Glass: Wikis

  
  
  
  
  

Did you know ...


More interesting facts on Glass

Include this on your site/blog:

Encyclopedia

From Wikipedia, the free encyclopedia

Moldavite, a natural glass formed by meteorite impact, from Besednice, Bohemia
A modern greenhouse in Wisley Garden, England, made from float glass
Clear glass light bulb
.A glass is an amorphous (non-crystalline) solid material.^ The physical and atomic characteristics of glass are treated in amorphous solid .
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ Pronunciation Key A usually transparent or translucent material that has no crystalline structure yet behaves like a solid.
  • Glass Definition | Definition of Glass at Dictionary.com 8 January 2010 23:13 UTC dictionary.reference.com [Source type: Reference]

^ Distinction between crystalline and amorphous solids ; in amorphous solid (physics): Magnetic glasses ) brittleness ( in ceramic composition and properties: Brittleness ) bulk modulus ( in bulk modulus (physics) ) use in .
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

.Glasses are typically brittle, and often optically transparent.^ Glass used for decorative purposes often has iron in it to alter its optical properties.
  • Glass Definition | Definition of Glass at Dictionary.com 8 January 2010 23:13 UTC dictionary.reference.com [Source type: Reference]

^ The qualities required in optical glasses have already been partly referred to, but may now be summarized: I. Transparency and Freedom from Colour.

^ As typical of the range of modern optical glasses Table I. is given, which constituted the list of optical glasses exhibited by Messrs Chance at the Optical Convention in London in 1905.

.Glass is commonly used for windows, bottles, modern hard drives and eyewear; examples of glassy materials include soda-lime glass, borosilicate glass, acrylic glass, sugar glass, Muscovy-glass, and aluminium oxynitride.^ The glass used in windows and windshields, called soda glass, is made by melting a silicate with sodium carbonate (soda) and calcium oxide (lime).
  • Glass Definition | Definition of Glass at Dictionary.com 8 January 2010 23:13 UTC dictionary.reference.com [Source type: Reference]

^ In making sheet glass it is customary to use 6 percent of lime and 4 percent of magnesia ( magnesium oxide , or MgO), and in bottle glass about 2 percent alumina ( aluminum oxide , or Al 2 O 3 ) is often present.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ A hard, brittle, translucent, and commonly transparent substance, white or colored, having a conchoidal fracture, and made by fusing together sand or silica with lime, potash, soda, or lead oxide.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

.The term glass developed in the late Roman Empire.^ According to some experts, glass making hasn't changed much since the Roman Empire was still on the rise.
  • Glass Making: It’s Only Getting Greener : Planet Green 25 September 2009 3:29 UTC planetgreen.discovery.com [Source type: FILTERED WITH BAYES]

^ The Romans use more glass than any society until modern times and also more than many of the less developed societies use even today.
  • Iridescent Roman Glass 25 September 2009 3:29 UTC www.mmdtkw.org [Source type: FILTERED WITH BAYES]

^ It's clear that, at least by late Roman times, glass was cut with rotating abrasive wheels, but we don't know much about the mechanics of their tools.
  • Iridescent Roman Glass 25 September 2009 3:29 UTC www.mmdtkw.org [Source type: FILTERED WITH BAYES]

.It was in the Roman glassmaking center at Trier, now in modern Germany, that the late-Latin term glesum originated, probably from a Germanic word for a transparent, lustrous substance.^ Although modern glassmakers have mastered the layering process, we are not quite sure how the Romans did it.
  • Iridescent Roman Glass 25 September 2009 3:29 UTC www.mmdtkw.org [Source type: FILTERED WITH BAYES]

^ Modern glassmakers know how to do this -- by adding a bit of metallic gold to the glass mix -- but it was only proved recently that this is also the way Roman fabricators did it.
  • Iridescent Roman Glass 25 September 2009 3:29 UTC www.mmdtkw.org [Source type: FILTERED WITH BAYES]

[1]
.Strictly speaking, a glass is defined as an inorganic product of fusion which has been cooled through its glass transition to the solid state without crystallising.^ Thus, a glass is defined as an 'amorphous solid that shows a glass transition '.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ The finished product has the look and feel of traditional stained glass, but with the strength and integrity of a solid piece of safety glass.
  • Free crystal glass calgary Download 19 November 2009 18:23 UTC wareseeker.com [Source type: FILTERED WITH BAYES]

^ It appears that part of the roof of the limestone and plaster furnace collapsed into the melting glass making the cooled product useless -- glass with too much calcium crystallizes and can't be used.
  • Iridescent Roman Glass 25 September 2009 3:29 UTC www.mmdtkw.org [Source type: FILTERED WITH BAYES]

[2][3][4][5][6] .Many glasses contain silica as their main component and glass former.^ Commercial glasses may be divided into soda–lime–silica glasses and special glasses, most of the tonnage produced being of the former class.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ The Cologne museum contains many specimens of Roman glass, some of which are remarkable for their cut decoration.

[7] .The term "glass" is, however, often extended to all amorphous solids (and melts that easily form amorphous solids), including plastics, resins, or other silica-free amorphous solids.^ Cover block 26 extends towards the molten glass 24, forming two wings 27.
  • Method for glass making using an oxy-fuel fired distribution channel - Patent EP0633228 25 September 2009 3:29 UTC www.freepatentsonline.com [Source type: Reference]

^ The physical and atomic characteristics of glass are treated in amorphous solid .
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ The proportions in which these ingredients are mixed vary according to the exact quality of glass required and with the form and temperature of the melting furnace employed.

In addition, besides traditional melting techniques, any other means of preparation are considered, such as ion implantation, and the sol-gel method.[7] .Commonly, glass science and physics deal only with inorganic amorphous solids, while plastics and similar organics are covered by polymer science, biology and further scientific disciplines.^ Thus, a glass is defined as an 'amorphous solid that shows a glass transition '.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

Glass plays an essential role in science and industry. .The optical and physical properties of glass make it suitable for applications such as flat glass, container glass, optics and optoelectronics material, laboratory equipment, thermal insulator (glass wool), reinforcement fiber (glass-reinforced plastic, glass fiber reinforced concrete), and art.^ Glass metal , the fused material for making glass.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ Further, these glasses, when made from properly proportioned materials, possess a very considerable degree of chemical stability, which is amply sufficient for most optical purposes.

^ Containing a lower iron content, ExtraClear has a higher visible light transmission and offers superior optics and clarity compared to standard glass.

Contents

History

.The history of creating glass can be traced back to 3500BCE in Mesopotamia.^ Glass Vases's history can be traced back to the great Stone Age.
  • WHOLESALE GLASS VASES | FLORAL & WEDDING GLASS VASES | WGV International 8 January 2010 23:13 UTC www.wholesaleglassvasesint.com [Source type: General]

^ The members of Back-up Service Group had a fun day with glass and their children created their own designs in fusing technique.

^ Skip this Advertisement Encyclopædia Britannica glass CREATE MY glass NEW ARTICLE SUGGEST EDIT ARTICLE HISTORY ADD TO YOUR SITE COMMENT Science & Technology : : glass .
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

Glass production

Glass ingredients

Quartz sand (silica) as main raw material for commercial glass production
Oldest mouth-blown window-glass in Sweden (Kosta Glasbruk, Småland, 1742). In the middle is the mark from the glass blower's pipe.
.Pure silica (SiO2) has a "glass melting point"— at a viscosity of 10 Pa·s (100 P)— of over 2300 °C (4200 °F).^ Extra profitable packs of cheap glass chillums - 10, 50 and 100 pcs!

^ The glass is composed of 50% silica (sand), 30% soda, 10% potash and 10% lime .
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ Quartz    Family of glass that is almost pure silica.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

.While pure silica can be made into glass for special applications (see fused quartz), other substances are added to common glass to simplify processing.^ Quartz    Family of glass that is almost pure silica.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Fused Silica    Glasses in the Quartz family.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ In the 1920s a new mould-etch process was invented, in which art was etched directly into the mould, so that each cast piece emerged from the mould with the image already on the surface of the glass.
  • WHOLESALE GLASS VASES | FLORAL & WEDDING GLASS VASES | WGV International 8 January 2010 23:13 UTC www.wholesaleglassvasesint.com [Source type: General]

.One is sodium carbonate (Na2CO3), which lowers the melting point to about 1500 °C (2700 °F) in soda-lime glass; "soda" refers to the original source of sodium carbonate in the soda ash obtained from certain plants.^ The alkali of Syrian and Egyptian glass was soda ash , sodium carbonate, which can be extracted from the ashes of many plants, notably halophile seashore plants: (see saltwort ).
  • WHOLESALE GLASS VASES | FLORAL & WEDDING GLASS VASES | WGV International 8 January 2010 23:13 UTC www.wholesaleglassvasesint.com [Source type: General]

^ Such glasses are made from three main materials—sand ( silicon dioxide , or SiO 2 ), limestone ( calcium carbonate , or CaCO 3 ), and sodium carbonate (Na 2 CO 3 ).
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ In making sheet glass it is customary to use 6 percent of lime and 4 percent of magnesia ( magnesium oxide , or MgO), and in bottle glass about 2 percent alumina ( aluminum oxide , or Al 2 O 3 ) is often present.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

.However, the soda makes the glass water soluble, which is usually undesirable, so lime (calcium oxide (CaO), generally obtained from limestone), some magnesium oxide (MgO) and aluminium oxide (Al2O3) are added to provide for a better chemical durability.^ That make glass more durable.

^ In making sheet glass it is customary to use 6 percent of lime and 4 percent of magnesia ( magnesium oxide , or MgO), and in bottle glass about 2 percent alumina ( aluminum oxide , or Al 2 O 3 ) is often present.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ The addition of lime ( calcium oxide , or CaO), supplied by the limestone, renders the glass insoluble again, but too much makes a glass prone to devitrification— i.e., the precipitation of crystalline phases in certain ranges of temperature.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

.The resulting glass contains about 70 to 74% silica by weight and is called a soda-lime glass.^ Finely divided vegetable charcoal added to a soda-lime glass gives a yellow colour.

^ The varieties of glass used for the manufacture of table-ware and vases are the potash-lead glass, the soda-lime glass and the potash-lime glass.

^ Soda Glass This is a dull, brittle glass that contains no lead.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

[8] .Soda-lime glasses account for about 90% of manufactured glass.^ In making sheet glass it is customary to use 6 percent of lime and 4 percent of magnesia ( magnesium oxide , or MgO), and in bottle glass about 2 percent alumina ( aluminum oxide , or Al 2 O 3 ) is often present.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ Finely divided vegetable charcoal added to a soda-lime glass gives a yellow colour.

^ The glass is composed of 50% silica (sand), 30% soda, 10% potash and 10% lime .
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

.As well as soda and lime, most common glass has other ingredients added to change its properties.^ Other materials are also added, some being put in to assist in refining the glass ( i.e., to remove the bubbles left behind in the melting process), while others are added to improve its colour.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ The two other most remarkable examples of this cameo glass are an amphora at Naples and the Auldjo vase.

^ Finely divided vegetable charcoal added to a soda-lime glass gives a yellow colour.

.Lead glass, such as lead crystal or flint glass, is more 'brilliant' because the increased refractive index causes noticeably more "sparkles", while boron may be added to change the thermal and electrical properties, as in Pyrex.^ Crystal glass , ∨ Flint glass .
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ In this table n is the refractive index of the glass for sodium light (the D line of the solar spectrum), while the letters C, F and G' refer to lines in the hydrogen spectrum by which dispersion is now generally specified.

^ On the other hand, while in the older crown and flint glasses the relation between refraction and dispersion had been practically fixed, dispersion and refraction increasing regularly with the density of the glass, in some of the new glasses introduced by Abbe and Schott this relation is altered and a relatively low refractive index is accompanied by a relatively high dispersion, while in others a high refractive index is associated with low dispersive power.

Adding barium also increases the refractive index. .Thorium oxide gives glass a high refractive index and low dispersion, and was formerly used in producing high-quality lenses, but due to its radioactivity has been replaced by lanthanum oxide in modern eye glasses.^ High quality with low price.
  • Crystal Glass, Crystal Glass Manufacturers & Suppliers 19 November 2009 18:23 UTC www.alibaba.com [Source type: General]

^ Modern technology has also provided high-speed precision cutting tools, tools that Roman glass-cutters would have given their left -- well, never mind what they would have given.
  • Iridescent Roman Glass 25 September 2009 3:29 UTC www.mmdtkw.org [Source type: FILTERED WITH BAYES]

^ Glass soap , ∨ Glassmaker's soap , the black oxide of manganese or other substances used by glass makers to take away color from the materials for glass.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

.Large amounts of iron are used in glass that absorbs infrared energy, such as heat absorbing filters for movie projectors, while cerium(IV) oxide can be used for glass that absorbs UV wavelengths (biologically damaging ionizing radiation).^ As glass is the main component of your sunroom, we take pride in providing superior sunroom glass choices, such as the like the Energy Star rated Comfort-Gard Plus glass for use in various applications or climates.
  • Sunrooms and Sunroom Products – Patio Enclosures, Inc. 8 January 2010 23:13 UTC www.patioenc.com [Source type: General]

^ Try to avoid using an excessive amount of glass with this method.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Glass soap , ∨ Glassmaker's soap , the black oxide of manganese or other substances used by glass makers to take away color from the materials for glass.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

Another common glass ingredient is "cullet" (recycled glass). .The recycled glass saves on raw materials and energy.^ Small amount of the raw material (silver or gold) is dabbed on the glass surface.

^ Unless the raw material s are very pure, the glass produced by modern methods is green .
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

However, impurities in the cullet can lead to product and equipment failure.
.Finally, fining agents such as sodium sulfate, sodium chloride, or antimony oxide are added to reduce the bubble content in the glass.^ A drinking vessel; a tumbler; a goblet; hence, the contents of such a vessel; especially; spirituous liquors; as, he took a glass at dinner .
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ Glass of antimony , a vitreous oxide of antimony mixed with sulphide.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ Just added a beautiful Stevens & Williams bubble glass bowl .
  • Tiffin Pairpoint Steuben Moser Lundberg Studios Lotton Tiffany Antique Baccarat Fenton Daum Phoenix Consolidated Bimini Libbey WMF Webb vase Glass Art Deco Sinclaire Ikora Glass St. Saint Louis Art Nouveau Glass Eames Loetz Kralik Glass Contemporary Glass Fry Foval 8 January 2010 23:13 UTC www.glasshound.com [Source type: FILTERED WITH BAYES]

[8] .Glass batch calculation is the method by which the correct raw material mixture is determined to achieve the desired glass composition.^ Small amount of the raw material (silver or gold) is dabbed on the glass surface.

^ Determine the Correct Flame Size Flame sizes are determined by what you are attempting to do with the glass.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

Composition and properties

There are three classes of components for oxide glasses: network formers, intermediates, and modifiers. The network formers (silicon, boron, germanium) form a highly crosslinked network of chemical bonds. .The intermediates (titanium, aluminium, zirconium, beryllium, magnesium, zinc) can act as both network formers and modifiers, according to the glass composition.^ The addition of a modifier (there are others than Na 2 O, although Na 2 O is widely used), causes the glass network to become 'looser', making processing of the glass easier.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

.The modifiers (calcium, lead, lithium, sodium, potassium) alter the network structure; they are usually present as ions, compensated by nearby non-bridging oxygen atoms, bound by one covalent bond to the glass network and holding one negative charge to compensate for the positive ion nearby.^ Hold glass tubing  in one hand  .
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ The presence of the 'bridging' oxygen ions makes a three-dimensional network structure possible.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ They consist of a network of (usually metallic) ion s, connected by oxide ions.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

Some elements can play multiple roles; e.g. lead can act both as a network former (Pb4+ replacing Si4+), or as a modifier.
.The presence of non-bridging oxygens lowers the relative number of strong bonds in the material and disrupts the network, decreasing the viscosity of the melt and lowering the melting temperature.^ The oxygen ion from the Na 2 O molecule fills up the space in the incomplete tetrahedron, resulting in two so-called non-bridging oxygen ions.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ The presence of the 'bridging' oxygen ions makes a three-dimensional network structure possible.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ To remedy this, its structure is modified by adding Na 2 O. Each Na 2 O molecule reacts with the silica network by breaking up the network at the site of a bridging oxygen ion.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

.The alkaline metal ions are small and mobile; their presence in glass allows a degree of electrical conductivity, especially in molten state or at high temperature.^ (Site Excerpt) In ancient times molten glass was kept in a liquid state .

^ Modifying the temperature of the molten glass brings the glass to a viscosity required for forming.
  • Method for glass making using an oxy-fuel fired distribution channel - Patent EP0633228 25 September 2009 3:29 UTC www.freepatentsonline.com [Source type: Reference]

^ Therefore, a need exists for a method of making glass comprising an improved method of modifying the temperature of the molten glass in a distribution channel.
  • Method for glass making using an oxy-fuel fired distribution channel - Patent EP0633228 25 September 2009 3:29 UTC www.freepatentsonline.com [Source type: Reference]

.Their mobility however decreases the chemical resistance of the glass, allowing leaching by water and facilitating corrosion.^ Borosilicate glass appreciable resistance to high temperature or sudden changes in temperature medium resistance to chemical attack moderately expensive to make.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ In addition to outstanding resistance to heat and thermal shock, borosilicate glasses are known for chemical durability and low coefficients of thermal expansion.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ The essential qualities of a bottle are strength and power to resist chemical corrosion.

.Alkaline earth ions, with their two positive charges and requirement for two non-bridging oxygens to compensate for their charge, are much less mobile themselves and also hinder diffusion of other ions, especially the alkalis.^ The oxygen ions form the bridges between the units; each 'bridging' oxygen is shared by two tetrahedral units so that the overall formule turns out to be SiO 2 , not SiO 4 as you might suspect from the basic unit.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ To remedy this, its structure is modified by adding Na 2 O. Each Na 2 O molecule reacts with the silica network by breaking up the network at the site of a bridging oxygen ion.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ The oxygen ion from the Na 2 O molecule fills up the space in the incomplete tetrahedron, resulting in two so-called non-bridging oxygen ions.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

.The most common commercial glasses contain both alkali and alkaline earth ions (usually sodium and calcium), for easier processing and satisfying corrosion resistance.^ Glass has always been present on Earth , formed whenever certain silicon -containing rocks melt due to phenomena such as volcanic eruption s, lightning strike s or the impact of meteorite s, and then cool rapidly, solidifying in the process.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ Such glasses are made from three main materials—sand ( silicon dioxide , or SiO 2 ), limestone ( calcium carbonate , or CaCO 3 ), and sodium carbonate (Na 2 CO 3 ).
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ Access to a glass saw or cut-off wheel can make this process easier for some.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

[9] Corrosion resistance of glass can be achieved by dealkalization, removal of the alkali ions from the glass surface by reaction with e.g. sulfur or fluorine compounds. .Presence of alkaline metal ions has also detrimental effect to the loss tangent of the glass, and to its electrical resistance; glasses for electronics (sealing, vacuum tubes, lamps...^ Butt Seals     Butt Sealing is the process of joining two sections of glass tubing together - end to end.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Select 10 mm glass tubing about 16 inches long, blowhose attached at one end, sealed at the other.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ The processes employed in the manufacture of the glass bulbs for incandescent electric lamps, are similar to the old- FIG. 19.

) have to take this in account.
.Addition of lead(II) oxide lowers melting point, lowers viscosity of the melt, and increases refractive index.^ To reduce the melting point of silica, it is necessary to add a flux; this is the purpose of the sodium carbonate ( soda ash ), which makes available the fluxing agent sodium oxide .
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ By adding about 25 percent of the sodium oxide to silica, the melting point is reduced from 1,723° to 850° C (3,133° to 1,562° F).
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

.Lead oxide also facilitates solubility of other metal oxides, leading to its use in colored glasses.^ In making sheet glass it is customary to use 6 percent of lime and 4 percent of magnesia ( magnesium oxide , or MgO), and in bottle glass about 2 percent alumina ( aluminum oxide , or Al 2 O 3 ) is often present.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ The present method of making glass articles may be used with other known methods of modifying the temperature of glass in a distribution channel.
  • Method for glass making using an oxy-fuel fired distribution channel - Patent EP0633228 25 September 2009 3:29 UTC www.freepatentsonline.com [Source type: Reference]

^ Glass soap , ∨ Glassmaker's soap , the black oxide of manganese or other substances used by glass makers to take away color from the materials for glass.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

.The viscosity decrease of lead glass melt is very significant (roughly 100 times in comparison with soda glasses); this allows easier removal of bubbles and working at lower temperatures, hence its frequent use as an additive in vitreous enamels and glass solders.^ Other materials are also added, some being put in to assist in refining the glass ( i.e., to remove the bubbles left behind in the melting process), while others are added to improve its colour.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ Fused silica itself is an excellent glass, but, as the melting point of sand (crystalline silica) is above 1,700° C (3,092° F) and as it is very expensive to attain such high temperatures, its uses are restricted to those in which its superior properties—chemical inertness and the ability to withstand sudden changes of temperature—are so important that the cost is justified.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ Glass has been made into practical and decorative objects since ancient times, and it is still very important in applications as disparate as building construction , housewares, and telecommunications.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

.The high ionic radius of the Pb2+ ion renders it highly immobile in the matrix and hinders the movement of other ions; lead glasses therefore have high electrical resistance, about two orders of magnitude higher than soda-lime glass (108.5 vs 106.5 ohm/cm, DC at 250°C).^ Select 10 mm glass tubing about 16 inches long, blowhose attached at one end, sealed at the other.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Empire Level's Open Reel Fiber Glass Measuring Tapes feature heavy duty construction, a high impact resistant ABS...
  • Glass Making Tools - Shop Smarter.com 25 September 2009 3:29 UTC www.smarter.com [Source type: General]

^ There were only two other glass companies that used a flower finial and they were Cambridge and Steuben.
  • Fenton's 100 Years of Glass Making by Debbie and Randy Coe 25 September 2009 3:29 UTC www.coesmercantile.com [Source type: General]

.For more details, see lead glass.^ The customers also became more interested in Fenton and came to tour the facility to see where the glass was made.
  • Fenton's 100 Years of Glass Making by Debbie and Randy Coe 25 September 2009 3:29 UTC www.coesmercantile.com [Source type: General]

[10]

Contemporary glass production

.Following the glass batch preparation and mixing, the raw materials are transported to the furnace.^ The Glass Furnace invites young glass lovers to introduce this magical material during the school season.

^ They did not have not enough fuel for the small furnace, and the necessary raw material was brought by scanty parties.
  • News & Information - Bohemian Crystal Glass Art Studios 19 November 2009 18:23 UTC www.design-glassware.com [Source type: General]

^ The proportions in which these ingredients are mixed vary according to the exact quality of glass required and with the form and temperature of the melting furnace employed.

.Soda-lime glass for mass production is melted in gas fired units.^ Overall, oxy/fuel firing provides a 90% reduction in the volume, or mass, of exhaust gases, lowering turbulence and surface glass losses.
  • Method for glass making using an oxy-fuel fired distribution channel - Patent EP0633228 25 September 2009 3:29 UTC www.freepatentsonline.com [Source type: Reference]

^ The glass is composed of 50% silica (sand), 30% soda, 10% potash and 10% lime .
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ There are four major families of glass, each a variation on the basic soda-lime glass and named after its additive s.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

.Smaller scale furnaces for specialty glasses include electric melters, pot furnaces, and day tanks.^ The Glass Furnace by 7 groups for 5 consecutive days, viewing various glass techniques in the workshops and having their own creative experience with glass in the fusion workshop.

^ The Glass Furnace hosted glass and stained glass artist Heyecan Ural for two day fusing workshop.

^ They have kept their own desings of beads as a souvenir of a beautiful day at glass furnace.

[8]
.After melting, homogenization and refining (removal of bubbles), the glass is formed.^ Other materials are also added, some being put in to assist in refining the glass ( i.e., to remove the bubbles left behind in the melting process), while others are added to improve its colour.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ Melt glass evenly down, forming a hole 10 mm in diameter with level 3 mm high side walls.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Reheat bubble and let glass collapse to a flat even plateau, remove torch.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

.Flat glass for windows and similar applications is formed by the float glass process, developed between 1953 and 1957 by Sir Alastair Pilkington and Kenneth Bickerstaff of the UK's Pilkington Brothers, who created a continuous ribbon of glass using a molten tin bath on which the molten glass flows unhindered under the influence of gravity.^ An effort at a more direct mechanical process is embodied in the inventions of Foucault which are at present being developed in Germany and Belgium ; in this process the glass is drawn from the molten bath in the shape of flat sheets, by the aid of a bar of iron, previously immersed in the glass, the glass receiving its form by being drawn through slots in large fire-bricks, and being kept in shape by rapid chilling produced by the action of air-blasts.

^ Tube was heated excessively causing glass to flow with gravity.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ This exercise will introduce you to the process of blowing into the glass, forming and shaping the tube end.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

.The top surface of the glass is subjected to nitrogen under pressure to obtain a polished finish.^ A good fire polish has a smooth finish and the ID and OD of the glass tube remains unchanged.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ D Laser Crystal 1) Polished from top K9 optical glass crystal 2) Artistically designed 3) Can be designedm personally...
  • Crystal Glass, Crystal Glass Manufacturers & Suppliers 19 November 2009 18:23 UTC www.alibaba.com [Source type: General]

^ Gas lines that hang from above or lay on top of the work surface will be exposed to flames and hot glass (not desirable)!
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

[11] .Container glass for common bottles and jars is formed by blowing and pressing methods.^ Their main line of glass products consisted of various kinds of bottles and fruit jars.
  • GLASS FACTORIES THAT MANUFACTURED INSULATORS 8 January 2010 23:13 UTC www.myinsulators.com [Source type: FILTERED WITH BAYES]

^ A sufficient weight of molten glass to form a bottle is gathered and placed in a funnel-shaped vessel which serves as a measure, and gives access to the mould which shapes the outside of the neck.

^ When the air has forced the glass to take the form of the mould, the mould is opened and the blower gives the blowing iron with the bottle attached to it to the " wetter off."

.Further glass forming techniques are summarized in the table Glass forming techniques.^ Warm Glass Board -- The bulletin board on this website, which is devoted strictly to fusing, slumping, and kiln-forming techniques.
  • Warm Glass -- your source for in 8 January 2010 23:13 UTC www.warmglass.com [Source type: General]

^ Art Glass Fusing Center -- Retailer of fusing supplies.  Offers numerous classes in kiln-forming techniques.  (Texas, USA)  A Warm Glass website sponsor .
  • Warm Glass -- your source for in 8 January 2010 23:13 UTC www.warmglass.com [Source type: General]

Once the desired form is obtained, glass is usually annealed for the removal of stresses. .Surface treatments, coatings or lamination may follow to improve the chemical durability (glass container coatings, glass container internal treatment), strength (toughened glass, bulletproof glass, windshields), or optical properties (insulated glazing, anti-reflective coating).^ A brief treatment of glass follows.
  • glass -- Britannica Online Encyclopedia 8 January 2010 23:13 UTC www.britannica.com [Source type: Reference]

^ Although Novelty Glass was dissolved in 1903, the factory itself may have produced insulators as late as 1907 under a succeeding firm's ownership.
  • GLASS FACTORIES THAT MANUFACTURED INSULATORS 8 January 2010 23:13 UTC www.myinsulators.com [Source type: FILTERED WITH BAYES]

^ The wings may project to any desired height, but preferably project to just above or just below the surface of the glass flowing through the distribution channel.
  • Method for glass making using an oxy-fuel fired distribution channel - Patent EP0633228 25 September 2009 3:29 UTC www.freepatentsonline.com [Source type: Reference]

Glassmaking in the laboratory

A vitrification experiment for the study of nuclear waste disposal at Pacific Northwest National Laboratory.
Failed laboratory glass melting test. The striations must be avoided through good homogenization.
.New chemical glass compositions or new treatment techniques can be initially investigated in small-scale laboratory experiments.^ The precise colour needed depends on the oxidation state of the colourant, the composition of the glass and the thermal treatment.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ Assuming the glassware was broken in use, or has been used in the laboratory at some point in time, it would be wise to assume the glass has some chemical residue on or in it.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

.The raw materials for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority.^ Glasses can be manufactured in different ways and from different materials.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ The mass production of fittings during the twenties and later led to the widespread use of moulded glass for both hanging and wall lights, and the amount of brass used in these designs was very much reduced.
  • News & Information - Bohemian Crystal Glass Art Studios 19 November 2009 18:23 UTC www.design-glassware.com [Source type: General]

^ Glass soap , ∨ Glassmaker's soap , the black oxide of manganese or other substances used by glass makers to take away color from the materials for glass.
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

.In the laboratory mostly pure chemicals are used.^ Assuming the glassware was broken in use, or has been used in the laboratory at some point in time, it would be wise to assume the glass has some chemical residue on or in it.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

Care must be taken that the raw materials have not reacted with moisture or other chemicals in the environment (such as alkali oxides and hydroxides, alkaline earth oxides and hydroxides, or boron oxide), or that the impurities are quantified (loss on ignition).[12] .Evaporation losses during glass melting should be considered during the selection of the raw materials, e.g., sodium selenite may be preferred over easily evaporating SeO2.^ The Glass Furnace invites young glass lovers to introduce this magical material during the school season.

^ You may find that painting the bench top and back shield flat black will help in determining the color of heated glass during the glassblowing process.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ GlassStands.com -- Extensive selection of stands and related materials for displaying glass (Texas USA)  A Warm Glass website sponsor .
  • Warm Glass -- your source for in 8 January 2010 23:13 UTC www.warmglass.com [Source type: General]

Also, more readily reacting raw materials may be preferred over relatively inert ones, such as Al(OH)3 over Al2O3. Usually, the melts are carried out in platinum crucibles to reduce contamination from the crucible material. .Glass homogeneity is achieved by homogenizing the raw materials mixture (glass batch), by stirring the melt, and by crushing and re-melting the first melt.^ Unless the raw material s are very pure, the glass produced by modern methods is green .
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

.The obtained glass is usually annealed to prevent breakage during processing.^ Tempered sunroom glass keeps you safe during accidental breakage, by allowing the glass to shatter into tiny pieces instead of sharp glass shards.
  • Sunrooms and Sunroom Products – Patio Enclosures, Inc. 8 January 2010 23:13 UTC www.patioenc.com [Source type: General]

^ You may find that painting the bench top and back shield flat black will help in determining the color of heated glass during the glassblowing process.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Equipment, Material, Tools and Terminology Anneal    Term used to describe the process of removing stresses introduced into the glassware during the glassblowing process.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

[12][13]
.In order to make glass from materials with poor glass forming tendencies, novel techniques are used to increase cooling rate, or reduce crystal nucleation triggers.^ Among the most successful design works – carelessly generated glass figures and a collection made with use of special techniques.
  • News & Information - Bohemian Crystal Glass Art Studios 19 November 2009 18:23 UTC www.design-glassware.com [Source type: General]

^ Tip: Heating large areas of of glass using this technique may give you control problems at step #6.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Warm Glass Board -- The bulletin board on this website, which is devoted strictly to fusing, slumping, and kiln-forming techniques.
  • Warm Glass -- your source for in 8 January 2010 23:13 UTC www.warmglass.com [Source type: General]

Examples of these techniques include aerodynamic levitation (the melt is cooled whilst floating in a gas stream), splat quenching, (the melt is pressed between two metal anvils) and roller quenching (the melt is poured through rollers).

Sol-gel science/technology

Silica-free glasses

.Besides common silica-based glasses, many other inorganic and organic materials may also form glasses, including plastics (e.g., acrylic glass), amorphous carbon, metals, carbon dioxide (see below), phosphates, borates, chalcogenides, fluorides, germanates (glasses based on GeO2), tellurites (glasses based on TeO2), antimonates (glasses based on Sb2O3), arsenates (glasses based on As2O3), titanates (glasses based on TiO2), tantalates (glasses based on Ta2O5), nitrates, carbonates and many other substances.^ Many forms of apparatus have been tried for ascertaining the temperature of glass furnaces.

^ Semi-opacity due to crystallization may be induced in many glasses by maintaining them for a long period at a.

^ Many specimens exist of German winged and enamelled glasses of Venetian character.

[7]
.Some glasses that do not include silica as a major constituent may have physico-chemical properties useful for their application in fibre optics and other specialized technical applications.^ Handmade-Glass.com -- The "other Brad" board, this is Brad Shute's board, which is the place to go for more technical questions about glass making, lampworking, and such.   .
  • Warm Glass -- your source for in 8 January 2010 23:13 UTC www.warmglass.com [Source type: General]

^ Assuming the glassware was broken in use, or has been used in the laboratory at some point in time, it would be wise to assume the glass has some chemical residue on or in it.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

These include fluoride glasses (fluorozirconates, fluoroaluminates), aluminosilicates, phosphate glasses, borate glasses, and chalcogenide glasses.
.Under extremes of pressure and temperature solids may exhibit large structural and physical changes which can lead to polyamorphic phase transitions.^ Owing to the physical changes produced in the material exposed prolonged observations of temperature are impossible.

[14] In 2006 Italian scientists created an amorphous phase of carbon dioxide using extreme pressure. The substance was named amorphous carbonia(a-CO2) and exhibits an atomic structure resembling that of silica.[15]

Physics of glass

See also Physics of glass
Unsolved problems in physics
What is the nature of the transition between a fluid or regular solid and a glassy phase? What are the physical mechanisms giving rise to the general properties of glasses? Question mark2.svg
The amorphous structure of glassy Silica (SiO2) in two dimensions. No long range order is present, however there is local ordering with respect to the tetrahedral arrangement of Oxygen (O) atoms around the Silicon (Si) atoms.
.The standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching.^ Plate glass is, nevertheless, considerably used for the cheaper forms of lenses, where the scattering of the light and loss of definition arising from these fine striae is not readily recognized.

^ The crucible with the semi-solid glass which it contains is now allowed to cool considerably in the melting furnace, or it may be removed to another slightly heated furnace.

^ Melt glass evenly down, forming a hole 10 mm in diameter with level 3 mm high side walls.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

[3][4][5][16] .If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crystallization is prevented and instead the disordered atomic configuration of the supercooled liquid is frozen into the solid state at the glass transition temperature Tg.^ Place the shoulder of the glass point into the flame at an angle - rotating at all times - and pull off the excess glass, leaving a semi-rounded bottom.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ A similar glass, if its cooling is greatly retarded, produces throughout its substance minute crystals of metallic copper, and closely resembles the mineral called avanturine.

^ The crucible with the semi-solid glass which it contains is now allowed to cool considerably in the melting furnace, or it may be removed to another slightly heated furnace.

.Generally, the structure of a glass exists in a metastable state with respect to its crystalline form, although in certain circumstances, for example in atactic polymers, there is no crystalline analogue of the amorphous phase.^ While it was a chance of a lifetime to make our own glass, there is no chance we will put any of Fenton’s workers out of a job.
  • Fenton's 100 Years of Glass Making by Debbie and Randy Coe 25 September 2009 3:29 UTC www.coesmercantile.com [Source type: General]

^ As a general rule, to which, however, there are important exceptions, both these qualities are found to a greater degree, the lower the refractive index of the glass.

^ Little is known about the actual cause of colour in glass beyond the fact that certain materials added to and melted with certain glass-mixtures will in favourable circumstances produce effects of colour.

[17] .As in other amorphous solids, the atomic structure of a glass lacks any long range translational periodicity.^ Besides the making of vessels of all kinds the factories of Murano had for a long period almost an entire monopoly of two other branches of the art - the making of mirrors and of beads.

^ Select 10 mm glass tubing about 16 inches long, blowhose attached at one end, sealed at the other.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Semi-opacity due to crystallization may be induced in many glasses by maintaining them for a long period at a.

.However, due to chemical bonding characteristics glasses do possess a high degree of short-range order with respect to local atomic polyhedra.^ Further, these glasses, when made from properly proportioned materials, possess a very considerable degree of chemical stability, which is amply sufficient for most optical purposes.

^ Working Range    Temperature at which glass is hot enough to shape and seal or bond.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ As a general rule, to which, however, there are important exceptions, both these qualities are found to a greater degree, the lower the refractive index of the glass.

[18] .It is deemed that the bonding structure of glasses, although disordered, has the same symmetry signature (Hausdorff-Besicovitch dimensionality) as for crystalline materials.^ Fragments of glass of the same composition as that aimed at are generally incorporated to a limited extent with the mixed raw materials to facilitate their fusion.

[19]

Glass versus a supercooled liquid

Glass is generally classed as an amorphous solid rather than a liquid.[16][20] .Glass displays all the mechanical properties of a solid.^ As regards both mode of production and essential properties optical glass differs widely from all other varieties.

^ Collectors from all across the United States converged on Williamstown, West Virginia for several days of bingo, displays, glass sales, seminars and factory tours.
  • Fenton's 100 Years of Glass Making by Debbie and Randy Coe 25 September 2009 3:29 UTC www.coesmercantile.com [Source type: General]

.The notion that glass flows to an appreciable extent over extended periods of time is not supported by empirical research or theoretical analysis (see viscosity of amorphous materials).^ Fenton turned back to the Victorian time period for ideas for their glass.
  • Fenton's 100 Years of Glass Making by Debbie and Randy Coe 25 September 2009 3:29 UTC www.coesmercantile.com [Source type: General]

^ The glass, now in its approximate form, is placed in a heated chamber where it is allowed to cool very gradually - the minimum time of cooling from a dull red heat being six days, while for " fine annealing " a much longer period is required (see above).

^ Fragments of glass of the same composition as that aimed at are generally incorporated to a limited extent with the mixed raw materials to facilitate their fusion.

.From a more commonsense point of view, glass should be considered a solid since it is rigid according to everyday experience.^ The Glass Furnace by 7 groups for 5 consecutive days, viewing various glass techniques in the workshops and having their own creative experience with glass in the fusion workshop.

^ The wall thickness of the glass will also be more apparent against a solid background.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

[21]
.Some people consider glass to be a liquid due to its lack of a first-order phase transition[20][22] where certain thermodynamic variables such as volume, entropy and enthalpy are discontinuous through the glass transition range.^ If glass-blowing had been a perfectly new invention of GraecoEgyptian or Roman times, some specimens illustrating the transition from core-moulding to blowing must have been discovered.

^ Although most of the vessels of this mille fiori glass were small, some were made as large as 20 in.

^ The various varieties of rolled plate-glass are now produced for some purposes with a reinforcement of wire netting which is embedded in the mass of the glass.

.However, the glass transition may be described as analogous to a second-order phase transition where the intensive thermodynamic variables such as the thermal expansivity and heat capacity are continuous.^ You may find that painting the bench top and back shield flat black will help in determining the color of heated glass during the glassblowing process.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Tip: Heating large areas of of glass using this technique may give you control problems at step #6.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ The crucible with the semi-solid glass which it contains is now allowed to cool considerably in the melting furnace, or it may be removed to another slightly heated furnace.

[23] . .Despite this, the equilibrium theory of phase transformations in solids does not entirely hold for glass, and hence the glass transition cannot be classed as one of the classical equilibrium phase transformations in solids.^ Hold glass tubing  in one hand  .
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Probably one of the most memorable events, for us, was to participate in the glass making class inside the Fenton factory.
  • Fenton's 100 Years of Glass Making by Debbie and Randy Coe 25 September 2009 3:29 UTC www.coesmercantile.com [Source type: General]

^ One workman holds the blowing iron with the mass of glass attached to it, and another fixes an iron rod by means of a seal of glass to the extremity of the mass.

[5]
.Although the atomic structure of glass shares characteristics of the structure in a supercooled liquid, glass tends to behave as a solid below its glass transition temperature.^ It has the most modern of electronics, yet next to the school shephards tend flocks while it thrives although there are few professional contemporary glass artists in the country.

^ When the glass has cooled so far as to become hard and solid, the furnace is hermetically sealed up and allowed to cool very gradually to the ordinary temperature.

^ M. de la Bastie's process of " toughening " glass consisted in dipping glass, raised to a temperature slightly below the melting-point, into molten tallow .

[24] A supercooled liquid behaves as a liquid, but it is below the freezing point of the material, and will crystallize almost instantly if a crystal is added as a core. .The change in heat capacity at a glass transition and a melting transition of comparable materials are typically of the same order of magnitude, indicating that the change in active degrees of freedom is comparable as well.^ For this reason every piece of pressed glass-ware, as soon as it is liberated from the mould, is exposed to a sharp heat in a small subsidiary furnace in order that the ruffled surface may be removed by melting.

^ This opening serves for the introduction of the glass-mixture, for the removal of the melted glass and as a source of heat for the processes of manipulation.

^ The process of sheet-glass manufacture described above is typical of that in use in a large number of works, but many modifications are to be found, particularly in the furnaces in which the glass is melted.

.Both in a glass and in a crystal it is mostly only the vibrational degrees of freedom that remain active, whereas rotational and translational motion is arrested.^ This only requires to be annealed and is then ready for cutting up, but the lump of glass by which the original globe was attached to the pipe remains as the bullion in the centre of the disk of glass.

^ As a general rule, to which, however, there are important exceptions, both these qualities are found to a greater degree, the lower the refractive index of the glass.

This helps to explain why both crystalline and non-crystalline solids exhibit rigidity on most experimental time scales.

Behavior of antique glass

.The observation that old windows are often thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a matter of centuries.^ Albert Hartshorne, Old English Glasses (London); E. W. Hulme, " English Glass-making in XVI. andXVII. Centuries," The Antiquary, Nos.

.It is then assumed that the glass was once uniform, but has flowed to its new shape, which is a property of liquid.^ On the other hand, the more extreme the optical properties of these new glasses, i.e.

[25] .In actuality, the reason for this is that when panes of glass were commonly made by glassblowers, the technique used was to spin molten glass so as to create a round, mostly flat and even plate (the crown glass process, described above).^ The glass is made in cylinders and in " crowns " or circles.

^ Crown and plate-glass .

^ Glassblowing Lathe    Equipment used as an aid in glass rotation.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

.This plate was then cut to fit a window.^ St Sofia when erected by Justinian had vaults covered with mosaics and immense windows filled with plates of glass fitted into pierced marble frames; some of the plates, 7 to 8 in.

.The pieces were not, however, absolutely flat; the edges of the disk became thicker as the glass spun.^ The abrasion is effected by pressing the glass against the edge of wheels, or disks, of hard material revolving on horizontal spindles.

^ The price, however, rapidly increases with the total bulk of perfect glass required in one piece, so that large disks of glass suitable for telescope objectives of wide aperture , or blocks for large prisms, become exceedingly costly.

.When actually installed in a window frame, the glass would be placed thicker side down both for the sake of stability and to prevent water accumulating in the lead cames at the bottom of the window.^ Place the shoulder of the glass point into the flame at an angle - rotating at all times - and pull off the excess glass, leaving a semi-rounded bottom.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ St Sofia when erected by Justinian had vaults covered with mosaics and immense windows filled with plates of glass fitted into pierced marble frames; some of the plates, 7 to 8 in.

^ Glass, in flat pieces, such as might be employed for windows, has been found in the ruins of Roman houses, both in England and in Italy , and in the house of the faun at Pompeii a small pane in a bronze frame remains.

[26] .Occasionally such glass has been found thinner side down or thicker on either side of the window's edge, as would be caused by carelessness at the time of installation.^ Traces of Roman glass manufactories have been found in Valencia and Murcia , in the valleys which run down to the coast of Catalonia , and near the mouth of the Ebro .

^ Glass, in flat pieces, such as might be employed for windows, has been found in the ruins of Roman houses, both in England and in Italy , and in the house of the faun at Pompeii a small pane in a bronze frame remains.

^ Melt glass evenly down, forming a hole 10 mm in diameter with level 3 mm high side walls.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

.Mass production of glass window panes in the early twentieth century caused a similar effect.^ The efforts made in France, Germany and England, in the 17th and 18th centuries, to improve the manufacture of glass in those countries had a very injurious effect on the industry of Murano.

^ Attempts to make mirrors of glass were made as early as A.D. 1317, but even in the 16th century mirrors of steel were still in use.

^ The double-handled blue-glass vase in the British Museum,dating from the 5th century, is probably a chalice , as it closely resembles the chalices represented on early Christian monuments.

.In glass factories, molten glass was poured onto a large cooling table and allowed to spread.^ When the glass has cooled so far as to become hard and solid, the furnace is hermetically sealed up and allowed to cool very gradually to the ordinary temperature.

^ The process consisted in spreading the leaf on a thin film of blown glass and pressing molten glass on to the leaf so that the molten glass cohered with the film of glass through the pores of the metallic leaf.

^ The crucible with the semi-solid glass which it contains is now allowed to cool considerably in the melting furnace, or it may be removed to another slightly heated furnace.

.The resulting glass is thicker at the location of the pour, located at the center of the large sheet.^ De Nehou's process of rolling molten glass poured on an iron table rendered the manufacture of very large plates possible.

^ The process of sheet-glass manufacture described above is typical of that in use in a large number of works, but many modifications are to be found, particularly in the furnaces in which the glass is melted.

These sheets were cut into smaller window panes with nonuniform thickness. .Modern glass intended for windows is produced as float glass and is very uniform in thickness.^ Until now, the typical result when laminating conventional clear float glass was color distortion and a reduction of visible light transmission as the laminate thickness increased.

^ For the production of thick sheets which are subsequently to be polished the process may thus claim considerable success, but it is not as yet possible to produce satisfactory sheet-glass by such means.

^ Guardian produces Architectural Laminated Glass in a full array of thicknesses and sizes.

Several other points exemplify the misconception of the "cathedral glass" theory:
  • Writing in the American Journal of Physics, physicist Edgar D. Zanotto states "...the predicted relaxation time for GeO2 at room temperature is 1032 years. .Hence, the relaxation period (characteristic flow time) of cathedral glasses would be even longer."^ Fenton turned back to the Victorian time period for ideas for their glass.
    • Fenton's 100 Years of Glass Making by Debbie and Randy Coe 25 September 2009 3:29 UTC www.coesmercantile.com [Source type: General]

    ^ Towards the middle of the 19th century it became the fashion to regard all cut-glass as barbarous, and services of even the best period were neglected and dispersed.

    ^ Staying at the Glass Furnace provides students with a time to learn, a time to relax, chat and share their glass and life experiences.

    [27] .(1032 years is many times longer than the estimated age of the Universe.^ In fact, glass with one of our DiamondGuard SRG coatings is proven to be over 10 times more scratch resistant than tempered and chemically strengthened glass.

    )
  • If medieval glass has flowed perceptibly, then ancient Roman and Egyptian objects should have flowed proportionately more — but this is not observed. .Similarly, prehistoric obsidian blades should have lost their edge; this is not observed either (although obsidian may have a different viscosity from window glass).^ The same oxide may produce different colours with different glass-mixtures, and different oxides of the same metal may produce different colours.

    ^ The stirring is therefore discontinued and the clay cylinder is either left embedded in the glass, or by the exercise of considerable force it may be gradually withdrawn.

    [20]
  • .
  • If glass flows at a rate that allows changes to be seen with the naked eye after centuries, then the effect should be noticeable in antique telescopes.^ The efforts made in France, Germany and England, in the 17th and 18th centuries, to improve the manufacture of glass in those countries had a very injurious effect on the industry of Murano.

    Any slight deformation in the antique telescopic lenses would lead to a dramatic decrease in optical performance, a phenomenon that is not observed.[20]
  • There are many examples of centuries-old glass shelving which has not bent, even though it is under much higher stress from gravitational loads than vertical window glass.
.Some glasses have a glass transition temperature close to or below room temperature.^ If glass-blowing had been a perfectly new invention of GraecoEgyptian or Roman times, some specimens illustrating the transition from core-moulding to blowing must have been discovered.

^ M. de la Bastie's process of " toughening " glass consisted in dipping glass, raised to a temperature slightly below the melting-point, into molten tallow .

.The behavior of a material that has a glass transition close to room temperature depends upon the timescale during which the material is manipulated.^ The Glass Furnace invites young glass lovers to introduce this magical material during the school season.

^ During the process of manipulation, whether on the chair or whilst the glass is being reheated, the rod must be constantly and gently trundled to prevent the collapse of the bulb or vessel.

^ During the class, they focused on covering and decorating glass by precious materials such as gold and platinum.

.If the material is hit it may break like a solid glass, but if the material is left on a table for a week it may flow like a liquid.^ The 3 artists working with the honey like texture of flowing hot glass compare themselves to bees and they are introducing their studio; their "kingdom" to Istanbul.

This simply means that for the fast timescale its transition temperature is above room temperature, but for the slow one it is below. The shift in temperature with timescale is not very large however, as indicated by the transition of polypropylene glycol of -72 °C and -71 °C over different timescales.[17] .To observe window glass flowing as liquid at room temperature we would have to wait a much longer time than any human can exist.^ This glass would be no less exciting than the times.
  • Fenton's 100 Years of Glass Making by Debbie and Randy Coe 25 September 2009 3:29 UTC www.coesmercantile.com [Source type: General]

^ The bowl is severed from the blowing iron, and the wine-glass is sent to the annealing oven with a bowl, longer than that of the finished glass, and with a rough fractured edge.

^ Finally, fluid steel can be run or poured off, since it is perfectly fluid, while glass cannot be thus treated, but is withdrawn from the furnace by means of either a ladle or a gatherer's pipe , and the temperature required for this purpose is much lower than.

.Therefore it is safe to consider a glass a solid far enough below its transition temperature: Cathedral glass does not flow because its glass transition temperature is many hundreds of degrees above room temperature.^ Working Range    Temperature at which glass is hot enough to shape and seal or bond.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Natural Gas* Fuel gas mixed with oxygen to generate temperatures hot enough to work borosilicate glass.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Because we offer a variety of high-quality glass options, AFG products are the first choice of many residential architects, designers, builders and remodelers.

Close to this temperature there are interesting time-dependent properties. One of these is known as aging. .Many polymers that we use in daily life such as polystyrene and polypropylene are in a glassy state but they are not too far below their glass transition temperature as opposed to rubber which is used above its glass transition temperature.^ Pluro Stopper    An adjustable size rubber stopper used in sealing openings in glass.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ There were only two other glass companies that used a flower finial and they were Cambridge and Steuben.
  • Fenton's 100 Years of Glass Making by Debbie and Randy Coe 25 September 2009 3:29 UTC www.coesmercantile.com [Source type: General]

^ During the class, they focused on covering and decorating glass by precious materials such as gold and platinum.

Their mechanical properties may well change over time and this is serious concern when applying these materials in construction. .In general for polymers there is a relation between the glass transition temperature and the speed of the deformation.^ Natural Gas* Fuel gas mixed with oxygen to generate temperatures hot enough to work borosilicate glass.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Propane*    Fuel gas mixed with oxygen to generate temperature hot enough to work borosilicate glass.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

Physical properties

Color

Common soda-lime float glass appears green in thick sections because of Fe2+ impurities.
.Many glasses have a chemical composition which includes what are referred to as absorption centers.^ Many of the vessels have four or as many as eight handles, and are decorated with serrated ornamentation, and with the trailed strands of glass already referred to.

^ Many glassblowers as policy will not accept glassware for repair until the user has cleaned the glass of all chemical and grease residue.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

.This may cause them to be selective in their absorption of visible lightwaves (or white light frequencies).^ Spectrally selective glass* is designed to combine excellent visible light transmittance with reduced infrared transmittance thereby reducing solar heat loads.

They absorb certain portions of the visible spectrum, while reflecting others. The frequencies of the spectrum which are not absorbed are either reflected back or transmitted for our physical observation. This is what gives rise to color.
.Thus, color in glass may be obtained by addition of electrically charged ions (or color centers) that are homogeneously distributed, and by precipitation of finely dispersed particles (such as in photochromic glasses).^ You may find that painting the bench top and back shield flat black will help in determining the color of heated glass during the glassblowing process.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ In 1574 Jacob Verzellini, a fugitive Venetian, residing in Antwerp, obtained a patent for making drinking-glasses in London " such as are made in Murano."

^ He obtained a knowledge of the methods of working practised in Bohemia by disguising himself as a porter , and thus worked for three years in a Bohemian glass-house.

[7] .Ordinary soda-lime glass appears colorless to the naked eye when it is thin, although iron(II) oxide (FeO) impurities of up to 0.1 wt%[28] produce a green tint which can be viewed in thick pieces or with the aid of scientific instruments.^ The invention, if it may be regarded as one, consisted in eliminating lime from the glass mixture, substituting refined potash for soda, and using a very large proportion of lead oxide.

^ Flint glass particularly, which appeared quite satisfactory when viewed in small pieces, was found to be so far from homogeneous as to be useless for lens construction.

^ Finely divided vegetable charcoal added to a soda-lime glass gives a yellow colour.

Further FeO and Cr2O3 additions may be used for the production of green bottles. .Sulfur, together with carbon and iron salts, is used to form iron polysulfides and produce amber glass ranging from yellowish to almost black.^ For melting the leadless glasses, open, bowl-shaped crucibles are used, ranging from 12 to 40 in.

^ In scientific glassblowing the glass used comes in tubing, rod or sheet form.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Solarcool Graylite Glass Solarcool Graylite glass provides a rich silver aesthetic when glazed with the reflective coating on the outboard (#1) surface and a dramatic, almost-black aesthetic when glazed with the reflective coating on the inboard (#2) surface.

[29] .Manganese dioxide can be added in small amounts to remove the green tint given by iron(II) oxide.^ Oxides of iron and manganese can only be used in glass manufacture in comparatively small quantities for the purpose of colouring or neutralizing colour in glass, and their introduction would not be a matter of sufficient importance to be specially recorded.

^ The material has been considered by some to be magnetic iron ore and by others oxide of manganese.

^ Manganese dioxide not only acts as a source of oxygen, but develops a pink tint in the glass, which is complementary to and neutralizes the green colour due to ferrous oxide.

Optical waveguides

The propagation of light through a multi-mode optical fiber.
A laser bouncing down an acrylic rod, illustrating the total internal reflection of light in a multimode optical fiber.
Optically transparent materials focus on the response of a material to incoming light waves of a range of wavelengths. Frequency selective optical filters can be utilized to alter or enhance the brightness and contrast of a digital image. .Guided light wave transmission via frequency selective waveguides involves the emerging field of fiber optics and the ability of certain glassy compositions as a transmission medium for a range of frequencies simultaneously (multimode optical fiber) with little or no interference between competing wavelengths or frequencies.^ Containing a lower iron content, ExtraClear has a higher visible light transmission and offers superior optics and clarity compared to standard glass.

.This resonant mode of energy and data transmission via electromagnetic (light) wave propagation, though low powered, is relatively lossless.^ Guardians ExtraClear low-iron float glass utilizes a new material formula that increases light transmission and color neutrality when compared to standard float glass.

.An optical fiber is a cylindrical dielectric waveguide that transmits light along its axis by the process of total internal reflection.^ There is also an intermediate stage in which the glass has a rusty red colour by reflected light, and a purpleblue colour by transmitted light.

The fiber consists of a core surrounded by a cladding layer. .To confine the optical signal in the core, the refractive index of the core must be greater than that of the cladding.^ As a general rule, to which, however, there are important exceptions, both these qualities are found to a greater degree, the lower the refractive index of the glass.

^ The optical desideratum is uniformity of refractive index and dispersive power throughout the mass of the glass.

.The index of refraction is a way of measuring the speed of light in a material.^ In this table n is the refractive index of the glass for sodium light (the D line of the solar spectrum), while the letters C, F and G' refer to lines in the hydrogen spectrum by which dispersion is now generally specified.

.(Note: The index of refraction is the ratio of the speed of light in a vacuum to the speed of light in a given medium.^ In this table n is the refractive index of the glass for sodium light (the D line of the solar spectrum), while the letters C, F and G' refer to lines in the hydrogen spectrum by which dispersion is now generally specified.

(The index of refraction of a vacuum is therefore equal to 1, by definition). The larger the index of refraction, the more slowly light travels in that medium. Typical values for core and cladding of an optical fiber are 1.48 and 1.46, respectively.
When light traveling in a dense medium hits a boundary at a steep angle, the light will be completely reflected. This effect is used in optical fibers to confine light in the core. Light travels along the fiber bouncing back and forth off of the boundary. .Because the light must strike the boundary with an angle greater than the critical angle, only light that enters the fiber within a certain range of angles will be propagated.^ Because Solarcool Azuria glass transmits more visible light than most competitive products, building interiors will be brighter and will require less artificial lighting.

This range of angles is called the acceptance cone of the fiber. The size of this acceptance cone is a function of the refractive index difference between the fiber's core and cladding.
Optical waveguides are used as components in integrated optical circuits (e.g. light-emitting diodes, LEDs) or as the transmission medium in local and long haul optical communication systems. Also of value to materials science is the sensitivity of materials to thermal radiation in the infrared (IR) portion of the EM spectrum. This infrared homing (or "heat-seeking") capability is responsible for such diverse optical phenomena as "night vision" and IR luminescence.

Modern glass art

A vase being created at the Reijmyre glassworks, Sweden
Paperweight with items inside the glass, Corning Museum of Glass
.
A glass sculpture by Dale Chihuly, “The Sun” at the “Gardens of Glass” exhibition in Kew Gardens, London.
^ Dale Chihuly, world's leading glass artist visited The Glass Furnace on June 24, 2006 .

^ As typical of the range of modern optical glasses Table I. is given, which constituted the list of optical glasses exhibited by Messrs Chance at the Optical Convention in London in 1905.

^ Before the cocktail party, Dale Chihuly came together with Beykoz Mayor Muharrem Ergul and masters/artists and students from session 3 of The Glass Furnace.

The piece is 13 feet (4 metres) high and made from 1000 separate glass objects.
Glass tiles mosaic (detail).
.From the 19th century, various types of fancy glass started to become significant branches of the decorative arts.^ Towards the end of the same century from 600 to 1000 workmen were, it is stated, employed on one branch of the art, that of ornamenting beads by the help of the blow-pipe.

^ In dealing with the manufacture of glass it is convenient to group the various branches in the following manner: Manufactured Glass.

^ Whether you are framing priceless art, a family photo or painting decorative glass, you expect the image to be clear and the colors to be true.

.Cameo glass was revived for the first time since the Romans, initially mostly used for pieces in a neo-classical style.^ In the 13th century the craft of glass-making was practised by the Moors in Almeria, and was probably a survival from Roman times.

^ If glass-blowing had been a perfectly new invention of GraecoEgyptian or Roman times, some specimens illustrating the transition from core-moulding to blowing must have been discovered.

^ The use of oxide of lead in glass-making was no new thing; it had been used, mainly as a flux , both by Romans and Venetians.

.The Art Nouveau movement in particular made great use of glass, with René Lalique, Émile Gallé, and Daum of Nancy important names in the first French wave of the movement, producing colored vases and similar pieces, often in cameo glass, and also using lustre techniques.^ Dancing Ladies items with their Art Nouveau style and opaque or transparent colors made them a favorite with customers.
  • Fenton's 100 Years of Glass Making by Debbie and Randy Coe 25 September 2009 3:29 UTC www.coesmercantile.com [Source type: General]

^ The name " patent plate " arose from the fact that certain patented devices originated by James Chance of Birmingham first made it possible to polish comparatively thin glass in this way.

^ But a modification of the first-named process was in use in the 4th and succeeding centuries, showing great ingenuity and manual dexterity, - that, namely, in which the added portions of glass are united to the body of the cup, not throughout, but only at points, and then shaped either by the wheel or by the hand (Plate I. fig.

.Louis Comfort Tiffany in America specialized in secular stained glass, mostly of plant subjects, both in panels and his famous lamps.^ Both groups left The Glass Furnace with appreciation and satisfaction; and we are also grateful to the officials that helped us host these special guests.

^ Stained Glass Organization of America .
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ The " Favrile " glass of Louis C. Tiffany of New York (Pl.

.From the 20th century, some glass artists began to class themselves as in effect sculptors working in glass, and as part of the fine arts.^ The participants at kilncasting class by Ebru Susamcolu , this time discovered the secretcs of working with glass and were fascinated by their works.

^ In the later part of the 17th century some glass decorated with enamel was made at Delhi .

^ Exceedingly fine canes of milk -white glass play an important part in the masterpieces produced by the Venetian glass-makers of the 16th century.

.Several of the most common techniques for producing glass art include: blowing, kiln-casting, fusing, slumping, pate-de-verre, flame-working, hot-sculpting and cold-working.^ Now, AFG's Patterned Glass offers architects, designers and builders the same freedom to create translucent works of art for a myriad of applications.

^ The glass being worked is moved into and around the flame.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ At The Glass Furnace, they spent time in the hot glass studio collaborating with some of Turkey's most accomplished glass masters and engaged in learning, applying, and experimenting with various hot and cold glass techniques.

.Cold work includes traditional stained glass work as well as other methods of shaping glass at room temperature.^ The uneven wall thickness will not heat to the working temperature uniformly, resulting in hot spots (thin wall) that blow out and cold spots (heavy wall) that do not move.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Compressed air is not capable of producing the flame temperatures necessary for working borosilicate and quartz glasses.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Working Range    Temperature at which glass is hot enough to shape and seal or bond.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

.Glass can also be cut with a diamond saw, or copper wheels embedded with abrasives, and polished to give gleaming facets; the technique used in creating Waterford crystal.^ Glass Saw (Cut-Off Wheel)    Equipment used to cut glass tubing and apparatus.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ Engraving is a process of drawing on glass by means of small copper wheels.

^ Tip: Heating large areas of of glass using this technique may give you control problems at step #6.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

[30] .Art is sometimes etched into glass via the use of acid, caustic, or abrasive substances.^ Sometimes purple glass is used in place of brown, probably with the design of imitating the precious murrhine.

^ The substances employed are the same as those used for the manufacture of sheet-glass, viz.

^ In the 16th century the fashion for using glass vessels of ornamental character spread from Italy into France and England.

Traditionally this was done after the glass was blown or cast. .In the 1920s a new mould-etch process was invented, in which art was etched directly into the mould, so that each cast piece emerged from the mould with the image already on the surface of the glass.^ Further, all the subsequent processes of cutting, moulding and annealing become increasingly difficult, owing to the greatly increased risk of breakage arising from either external injury or internal strain, as the dimensions of the individual piece of glass increase.

^ If glass-blowing had been a perfectly new invention of GraecoEgyptian or Roman times, some specimens illustrating the transition from core-moulding to blowing must have been discovered.

^ Although the moulds are heated, the surface of the glass is always slightly ruffled by contact with the mould.

.This reduced manufacturing costs and, combined with a wider use of colored glass, led to cheap glassware in the 1930s, which later became known as Depression glass.^ Many of the ornamental processes which we admire in Venetian glass were already in use in this century, as that of mille fiori, and the beautiful kind of glass known as " vitro di trina " or lace glass.

^ The varieties of glass used for the manufacture of table-ware and vases are the potash-lead glass, the soda-lime glass and the potash-lime glass.

^ The substances employed are the same as those used for the manufacture of sheet-glass, viz.

[31] As the types of acids used in this process are extremely hazardous, abrasive methods have gained popularity.
.Objects made out of glass include not only traditional objects such as vessels (bowls, vases, bottles, and other containers), paperweights, marbles, beads, but an endless range of sculpture and installation art as well.^ The Turkish ladies and gents cannot get enough of beads, and it is also my job to teach the other skills associated with flameworking such as sculpture off the mandrel, blown forms, filigree vessels etc...

^ The members of the club in other words employees of Turkey's leading holding, firstly joined beadmaking and fusing workshops and made their own glass beads and panels/plates.

^ As the school was full, not only did I meet some truly talented mosaicists but glass blowers and bead makers, Masters and students and some wonderful Turkish people as well...

.Colored glass is often used, though sometimes the glass is painted, innumerable examples exist of the use of stained glass.^ Whether you are framing priceless art, a family photo or painting decorative glass, you expect the image to be clear and the colors to be true.

^ Sometimes purple glass is used in place of brown, probably with the design of imitating the precious murrhine.

^ Silver oxide, mixed as a paint and spread on the surface of a piece of glass and heated, gives a permanent yellow stain.

Museums

.Apart from historical collections in general museums, modern works of art in glass can be seen in a variety of museums, including the Chrysler Museum, the Museum of Glass in Tacoma, the Metropolitan Museum of Art, the Toledo Museum of Art, and Corning Museum of Glass, in Corning, NY, which houses the world's largest collection of glass art and history, with more than 45,000 objects in its collection.^ The great variety of these vessels is well shown in the illustrated catalogue of GraecoEgyptian glass in the Cairo museum, edited by C. C. Edgar.

^ At the Glass Furnace, students have a chance to work with world renowned glass artists and masters while creating unforgettable memories.

^ Its more resistant to breakage than normal float glass.

[32]
.The Harvard Museum of Natural History has a collection of extremely detailed models of flowers made of painted glass.^ The author of the Atlante espanol, writing at the end of the 18th century, says that excellent glass was still made at Barcelona on Venetian models.

^ Imitations of natural stones were made by stirring together in a crucible glasses of different colours, or by incorporating fragments of differently coloured glasses into a mass of molten glass by rolling.

^ It has been proved that these variations depend to a great extent on the chemical nature of the glass of which the thermometer is made.

These were lampworked by Leopold Blaschka and his son Rudolph, who never revealed the method he used to make them. The Blaschka Glass Flowers are still an inspiration to glassblowers today.[33]

See also

References

  1. ^ Douglas, R. W. (1972). A history of glassmaking. Henley-on-Thames: G T Foulis & Co Ltd. ISBN 0854291172. 
  2. ^ ASTM definition of glass from 1945; also: DIN 1259, Glas – Begriffe für Glasarten und Glasgruppen, September 1986
  3. ^ a b Zallen, R. (1983). The Physics of Amorphous Solids. New York: John Wiley. ISBN 0471019682. 
  4. ^ a b Cusack, N. E. (1987). The physics of structurally disordered matter: an introduction. Adam Hilger in association with the University of Sussex press. ISBN 0852748299. 
  5. ^ a b c Elliot, S. R. (1984). Physics of Amorphous Materials. Longman group ltd. 
  6. ^ Horst Scholze (1991). Glass – Nature, Structure, and Properties. Springer. ISBN 0-387-97396-6. 
  7. ^ a b c d Werner Vogel (1994). Glass Chemistry (2 ed.). Springer-Verlag Berlin and Heidelberg GmbH & Co. K. ISBN 3540575723. 
  8. ^ a b c B. H. W. S. de Jong, "Glass"; in "Ullmann's Encyclopedia of Industrial Chemistry"; 5th edition, vol. A12, VCH Publishers, Weinheim, Germany, 1989, ISBN 3-527-20112-5, pp. 365–432.
  9. ^ http://books.google.com/books?id=34W4ZNDBHqQC&pg=PA64&dq=%22borate+glass%22&lr=&num=50&as_brr=3&cd=1#v=onepage&q=%22borate%20glass%22&f=false
  10. ^ http://books.google.com/books?id=ASIYuNCp81YC&pg=PA158&dq=%22glass+solders%22&lr=&as_drrb_is=q&as_minm_is=0&as_miny_is=&as_maxm_is=0&as_maxy_is=&num=50&as_brr=3&cd=3#v=onepage&q=%22glass%20solders%22&f=false
  11. ^ "PFG Glass". Pfg.co.za. http://www.pfg.co.za/about%20glass.htm. Retrieved 2009-10-24. 
  12. ^ a b "Glass melting, Pacific Northwest National Laboratory". Depts.washington.edu. http://depts.washington.edu/mti/1999/labs/glass_ceramics/mst_glass.html. Retrieved 2009-10-24. 
  13. ^ Alexander Fluegel. "Glass melting in the laboratory". Glassproperties.com. http://glassproperties.com/melting/. Retrieved 2009-10-24. 
  14. ^ P. F. McMillan (2004). "Polyamorphic transformations in liquids and glasses". Journal of Materials Chemistry 14: 1506–1512. doi:10.1039/b401308p. 
  15. ^ carbon dioxide glass created in the lab 15 June 2006, www.newscientisttech.com. Retrieved 3 August 2006.
  16. ^ a b S. A. Baeurle et al. (2006). "On the glassy state of multiphase and pure polymer materials". Polymer 47: 6243–6253&year=2006. doi:10.1016/j.polymer.2006.05.076. 
  17. ^ a b Folmer, J. C. W.; Franzen, Stefan (2003). "Study of polymer glasses by modulated differential scanning calorimetry in the undergraduate physical chemistry laboratory". Journal of Chemical Education 80 (7): 813. doi:10.1021/ed080p813. http://jchemed.chem.wisc.edu/Journal/Issues/2003/Jul/abs813.html. 
  18. ^ P.S. Salmon (2002). "Order within disorder". Nature Materials 1: 87. doi:10.1038/nmat737. 
  19. ^ M.I. Ojovan, W.E. Lee (2006). "Topologically disordered systems at the glass transition". J. Phys.: Condensed Matter 18: 11507–11520. doi:10.1088/0953-8984/18/50/007. 
  20. ^ a b c d Philip Gibbs. "Is glass liquid or solid?". http://math.ucr.edu/home/baez/physics/General/Glass/glass.html. Retrieved 2007-03-21. 
  21. ^ "Philip Gibbs" Glass Worldwide, (may/june 2007), pp 14–18
  22. ^ Jim Loy. "Glass Is A Liquid?". http://www.jimloy.com/physics/glass.htm. Retrieved 2007-03-21. 
  23. ^ M.I. Ojovan, W.E. Lee (2006). "Topologically disordered systems at the glass transition". J. Phys.: Condensed Matter 18: 11507–11520. doi:10.1088/0953-8984/18/50/007. 
  24. ^ Florin Neumann. "Glass: Liquid or Solid – Science vs. an Urban Legend". http://dwb.unl.edu/Teacher/NSF/C01/C01Links/www.ualberta.ca/~bderksen/florin.html. Retrieved 2007-04-08. 
  25. ^ Chang, Kenneth (2008-07-29). "The Nature of Glass Remains Anything but Clear". New York Times. http://www.nytimes.com/2008/07/29/science/29glass.html?ex=1375070400&en=048ade4011756b24&ei=5124&partner=permalink&exprod=permalink. Retrieved 2008-07-29. 
  26. ^ "Dr Karl's Homework: Glass Flows". Abc.net.au. 2000-01-26. http://www.abc.net.au/science/k2/homework/s95602.htm. Retrieved 2009-10-24. 
  27. ^ Zanotto, Edgar Dutra (1998). "Do Cathedral Glasses Flow?". American Journal of Physics 66: 392–396. doi:10.1119/1.19026. 
  28. ^ "High temperature glass melt property database for process modeling"; Eds.: Thomas P. Seward III and Terese Vascott; The American Ceramic Society, Westerville, Ohio, 2005, ISBN 1-57498-225-7
  29. ^ Substances Used in the Making of Coloured Glass 1st.glassman.com (David M Issitt). Retrieved 3 August 2006.
  30. ^ "Waterford Crystal Visitors Centre". http://www.waterfordvisitorcentre.com/. Retrieved 2007-10-19. 
  31. ^ "Depression Glass". http://www.glassonweb.com/articles/article/201/. Retrieved 2007-10-19. 
  32. ^ "Corning Museum of Glass". http://www.cmog.org/index.asp?pageId=1276. Retrieved 2007-10-14. 
  33. ^ the Harvard Museum of Natural History's page on the exhibit

Bibliography

  • Brugmann, Birte. .Glass Beads from Anglo-Saxon Graves: A Study on the Provenance and Chronology of Glass Beads from Anglo-Saxon Graves, Based on Visual Examination.^ It is probable that the glass drinking-vessels, which have been found in pre-Christian Anglo-Saxon tombs, were introduced from Germany.

    Oxbow Books, 2004. ISBN 1-84217-104-6
  • Ghosh, Amalananda (1990). An Encyclopaedia of Indian Archaeology. BRILL. ISBN 9004092625. 
  • Gowlett, J.A.J. (1997). High Definition Archaeology: Threads Through the Past. Routledge. ISBN 0415184290. 
  • Noel C. Stokes; The Glass and Glazing Handbook; Standards Australia; SAA HB125–1998

External links


Study guide

Up to date as of January 14, 2010

From Wikiversity

Crystal Clear app kaddressbook.png
Please help develop this page
This page was created, but so far, little content has been added. Everyone is invited to help expand and create educational content for Wikiversity. .If you need help learning how to add content, see the editing tutorial and the MediaWiki syntax reference.^ MB Crystal Astrology is a guiding tool that aims to help you in your quest of learning about the crystals and gems that possess healing properties.
  • Free crystal glass calgary Download 19 November 2009 18:23 UTC wareseeker.com [Source type: FILTERED WITH BAYES]

^ With  experience you will learn how much or hard to blow air, when to let gravity work for you, and even when to inhale to produce that certain look or shape.
  • Scientific Glassblowing Basics 8 January 2010 23:13 UTC www.ecu.edu [Source type: FILTERED WITH BAYES]

^ You can see the full Table of Contents on the main magazine page and find subscription information on the Subscribe Page.
  • SGAA - Stained Glass Association of America 8 January 2010 23:13 UTC stainedglass.org [Source type: General]

Please do not simply copy-and-paste large chunks from other projects.

Resources

See also


1911 encyclopedia

Up to date as of January 14, 2010
(Redirected to Database error article)

From LoveToKnow 1911

(There is currently no text in this page)


Wiktionary

Up to date as of January 15, 2010
(Redirected to glass article)

Definition from Wiktionary, a free dictionary

Contents

English

Wikipedia-logo.png
Wikipedia has an article on:
Most common English words: native « members « fortune « #959: glass » silver » winter » expect

Etymology

From Old English glæs, cognate with Old Saxon and Old High German glas (amber), which (in OHG) is attested as a gloss for Latin electrum (amber). These words are developed from Proto-Germanic *glaso-. Possibly ultimately from the Proto-Germanic root *glō-, *to shine (compare glow).

Pronunciation

Noun

a glass (2) of milk
Singular
glass
Plural
countable and uncountable; plural glasses
glass (countable and uncountable; plural glasses)
.
  1. (uncountable) A solid, transparent substance made by melting sand with a mixture of soda, potash and lime.^ A more important outcome, however, of Italian influence was the production, in emulation of Venetian glass, of a glass made of refined potash, lime and sand, which was more colourless than the material it was intended to imitate.

    ^ The invention, if it may be regarded as one, consisted in eliminating lime from the glass mixture, substituting refined potash for soda, and using a very large proportion of lead oxide.

    ^ The essential materials of which these mixtures are made are, for English flint glass, sand , carbonate of potash and red lead ; for plate and sheet glass, sand, carbonate or sulphate of soda.

    The tabletop is made of glass.
    .
  2. A vessel from which one drinks, especially one made of glass, plastic, or similar translucent or semi-translucent material.^ Although most of the vessels of this mille fiori glass were small, some were made as large as 20 in.

    ^ The coloured glass is usually not of one bright colour throughout, but semi-transparent and marbled; the colours in many instances are singularly fine and harmonious.

    ^ It is probable that the glass drinking-vessels, which have been found in pre-Christian Anglo-Saxon tombs, were introduced from Germany.

    Fill my glass with milk please.
  3. The quantity of liquid contained in such a vessel.
    Would you like a glass of milk?
  4. (physics, uncountable) Amorphous (non-crystalline) substance.
    A popular myth is that window glass actually is an extremely viscous liquid.
  5. (uncountable) Glassware.
    We collected art glass.
  6. A mirror.
    She adjusted her lipstick in the glass.
  7. A magnifying glass or telescope.
  8. (basketball, colloquial) The backboard.
    He caught the rebound off of the glass.
  9. (ice hockey) The clear, protective screen surrounding a hockey rink.
    He fired the outlet pass off the glass.

Derived terms

Translations

Adjective

glass (no comparative or superlative)
  1. (colloquial) Fragile.
    He has a glass ankle.

Translations

Verb

Infinitive
to glass
Third person singular
glasses
Simple past
glassed
Past participle
glassed
Present participle
glassing
to glass (third-person singular simple present glasses, present participle glassing, simple past and past participle glassed)
  1. (transitive) To furnish with glass; to glaze.
  2. (transitive) To enclose with glass.
  3. (transitive, British, colloquial) To strike (someone), particularly in the face, with a drinking glass with the intent of causing injury.
    • 1987, John Godber, Bouncers [1]
      JUDD. Any trouble last night? / LES. Usual. Couple of punks got glassed.
    • 2002, Geoff Doherty, A Promoters Tale [2]
      I often mused on what the politicians or authorities would say if they could see for themselves the horrendous consequences of someone who’d been glassed, or viciously assaulted.
    • 2003, Mark Sturdy, Pulp [3]
      One night he was in this nightclub in Sheffield and he got glassed by this bloke who’d been just let out of prison that day.
  4. To bombard an area with such intensity (nuclear bomb, fusion bomb, etc) as to melt the landscape into glass.

Interjection

glass
  1. (basketball) A warning called out to alert teammates that a shot is about to rebound off the backboard.
    The point guard launched a wobbly attempt at a three-pointer and immediately called "Glass!"

Anagrams

  • Anagrams of aglss
  • slags

Manx

Etymology 1

From Old Irish glas (blue-grey, green)

Adjective

glass
  1. green (of nature)
  2. grey (of animal)
  3. ashen (color/colour)
  4. verdant
  5. soft
  6. pale
  7. pasty
  8. raw
  9. unfledged
  10. sappy
  11. callow (of youth)

Etymology 2

From Old Irish glas (lock, clasp)

Noun

glass m. (plural glish)
  1. lock

Swedish

Pronunciation

Noun

Inflection for glass Singular Plural
common Indefinite Definite Indefinite Definite
Base form glass glassen glassar glassarna
Possessive form glass glassens glassars glassarnas
glass c.
  1. ice cream

Wikispecies

Up to date as of January 23, 2010
(Redirected to Charles Edward Glass article)

From Wikispecies

Charles Edward Glass, botanist (1934-1998)

Bible wiki

Up to date as of January 23, 2010

From BibleWiki

.
was known to the Egyptians at a very early period of their national history, at least B.C. 1500. Various articles both useful and ornamental were made of it, as bottles, vases, etc.
^ Various articles both useful and ornamental were made of it, as bottles, vases, etc.
  • Glass Definition | Definition of Glass at Dictionary.com 8 January 2010 23:13 UTC dictionary.reference.com [Source type: Reference]

^ The Free On-line Dictionary of Computing, © 1993-2007 Denis Howe Cite This Source Bible Dictionary Glass was known to the Egyptians at a very early period of their national history, at least B.C. 1500.
  • Glass Definition | Definition of Glass at Dictionary.com 8 January 2010 23:13 UTC dictionary.reference.com [Source type: Reference]

^ The only file board certified in every state in the USA. Made from float glass, the same process used to produce wine goblets and crystal vases.
  • Crystal Glass Nail File 19 November 2009 18:23 UTC www.pritinyc.com [Source type: General]

.A glass bottle with the name of Sargon on it was found among the ruins of the north-west palace of Nimroud.^ A glass bottle with the name of Sargon on it was found among the ruins of the north-west palace of Nimroud.
  • Glass Definition | Definition of Glass at Dictionary.com 8 January 2010 23:13 UTC dictionary.reference.com [Source type: Reference]

^ But ancient glass-makers made bottles, cups, beads, dice, chessmen, hairpins, pillars for theaters and palaces with lamps inside of them, and even glass coffins.
  • VII. Glass Making p2. A Look Through A Window Into One Of Nature's Workshops 25 September 2009 3:29 UTC chestofbooks.com [Source type: FILTERED WITH BAYES]

^ Also, a portion of the info is found in various articles in the 2-volume reference " INSULATORS: A HISTORY AND GUIDE TO NORTH AMERICAN GLASS PINTYPE INSULATORS " by John & Carol McDougald (1990).
  • GLASS FACTORIES THAT MANUFACTURED INSULATORS 8 January 2010 23:13 UTC www.myinsulators.com [Source type: FILTERED WITH BAYES]

The Hebrew word zekukith (Job 28:17), rendered in the Authorized Version "crystal," is rightly rendered in the Revised Version "glass." This is the only allusion to glass found in the Old Testament. .It is referred to in the New Testament in Rev 4:6; 15:2; 21:18, 21. In Job 37:18, the word rendered "looking-glass" is in the Revised Version properly rendered "mirror," formed, i.e., of some metal.^ So you see, when glass must be clear, as in spectacles and microscopes, cut glass and mirrors, no metals must be left in.
  • VII. Glass Making p2. A Look Through A Window Into One Of Nature's Workshops 25 September 2009 3:29 UTC chestofbooks.com [Source type: FILTERED WITH BAYES]

^ Colors were achieved by the addition of metals, usually in the form of oxides, because they were easier to mix into the re-melted raw glass.
  • Iridescent Roman Glass 25 September 2009 3:29 UTC www.mmdtkw.org [Source type: FILTERED WITH BAYES]

^ In the late 1970s, Crystal Glass formed a new company with some of the long-term employees, which evolved into the Crystal Employees Corporation.

(Comp. .Ex 38:8: "looking-glasses" are brazen mirrors, R.V.).^ Especially: (a) A looking-glass; a mirror .
  • glass@Everything2.com 8 January 2010 23:13 UTC everything2.com [Source type: FILTERED WITH BAYES]

^ It is referred to in the New Testament in Rev. In Job 37:18, the word rendered "looking-glass" is in the Revised Version properly rendered "mirror," formed, i.e., of some metal.
  • Glass Definition | Definition of Glass at Dictionary.com 8 January 2010 23:13 UTC dictionary.reference.com [Source type: Reference]

A mirror is referred to also in James 1:23.
This entry includes text from Easton's Bible Dictionary, 1897.
what mentions this? (please help by turning references to this page into wiki links)
This article needs to be merged with GLASS (Jewish Encyclopedia).

Simple English

Simple English Wiktionary has the word meaning for:

Glass is a hard material that can be made in many shapes. It is usually transparent, but it can also be made in colours.

Glass is often used to make windows and bottles. Many churches have windows made of colored glass.

The word "glass" can also refer to a drink container. It does not have to be made of glass, but can be made of any material, for example plastic.

Glass is used to make lenses. The word "glasses" is often used to mean eyeglasses.

The myth that glass is actually a liquid comes from the fact that old windows in houses and churches (2-300 years old) are sometimes a little out of shape: thicker at the bottom than the top. This phenomenon is actually due to the process of glass manufacture in the past which led to the glass pane being thicker at one edge than the other. It was sensible to install the windows with the thick edge at the bottom. Sometimes a window can be found with the thick edge at the top of the window.

Other websites

Error creating thumbnail: sh: convert: command not found
Wikimedia Commons has media related to:


rue:Скло


Citable sentences

Up to date as of December 16, 2010

Here are sentences from other pages on Glass, which are similar to those in the above article.








Got something to say? Make a comment.
Your name
Your email address
Message