SHREYA GLASS
Activities:
Well Glass Toughner
Contact:
MR. PRIYANK PALJA
Address:
2, Tirth Township, Court Rd., Dakor-388225 -INDIA
Tel.No:
( ) 9978286500
Select to Send Email Enquiry
more
Glass – Toughened Glass
Topics Covered
Background
Key Properties
Applications
Transport Industry
Building and Construction Industry
more
How is glass made? Read about toughened glass manufacture
Have you ever wondered how is glass made? Toughened glass is made from normal, float glass. This page gives you all the details you need to know.
Toughened glass starts life as float glass. Float glass, when shattered breaks into dagger like pieces and can be harmful, it is therefore unsuitable for some applications. Before undergoing the toughening process the glass parts must be cut to size. Any additional machining must be completed before the glass is toughened as it would shatter if it was cut in its toughened state.
In the toughening process, the surfaces of the glass are heated in a furnace. Recommended temperatures vary but the glass reaches temperatures of over 600°C. The hot glass is then cooled rapidly by a blast of air over a period of between 3 and 10 seconds. As a result, the surfaces shrink, and (at first) tensile stresses develop on the surfaces. As the bulk of the glass begins to cool, it contracts. The already solidified surfaces of the glass are then forced to contract, and consequently, they develop residual compressive surface stresses, while the interior zone develops compensating tensile stresses.
The tension zone in the core of the glass takes up about 60% of the cross-sectional area of the glass. Compressive surface stresses improve the strength of the glass in the same way that they do in other materials. The nature of the stresses is depicted in Fig. 1.
After the process the toughened glass has a greater resistance to thermal stresses and thermal shock and has improved flexural and tensile strength.
However, following characteristics remain unchanged; • Colour, • Clarity, • Chemical composition, • Light transmission, • Hardness, • Specific gravity, • Expansion coefficient, • Softening point, • Thermal conductivity, • Solar transmittance, • Stiffness.
The higher the coefficient of thermal expansion of the glass and the lower its thermal conductivity, the higher the level of residual stresses developed, and the stronger the glass becomes. Thermal toughening takes a relatively short time (minutes) and can be applied to most glasses. Because of the high amount of energy stored in residual stresses, tempered glass shatters into a large number of pieces when broken. The broken pieces are not as sharp and hazardous as those from ordinary glass.
Above is a representation of the main elements of a glass toughening facility. The size of the machinery required is dependant on the size of toughened glass parts one wishes to produce. However, for example a 1200 x 1300 mm bed which is designed for producing small parts, such as door panels would cost £140,000 + VAT (LGT Limited). This is towards the lower end of the price scale but second hand systems can be purchased for less.
Reference: Manufacturing Engineering and Technology Serope Kalpakjian
If you need some toughened glass, contact us with the details.
Return From How is Glass Made to Toughened Glass Page
more
Activities:
Well Glass Toughner
Contact:
MR. PRIYANK PALJA
Address:
2, Tirth Township, Court Rd., Dakor-388225 -INDIA
Tel.No:
( ) 9978286500
Select to Send Email Enquiry
more
Glass – Toughened Glass
Topics Covered
Background
Key Properties
Applications
Transport Industry
Building and Construction Industry
more
How is glass made? Read about toughened glass manufacture
Have you ever wondered how is glass made? Toughened glass is made from normal, float glass. This page gives you all the details you need to know.
Toughened glass starts life as float glass. Float glass, when shattered breaks into dagger like pieces and can be harmful, it is therefore unsuitable for some applications. Before undergoing the toughening process the glass parts must be cut to size. Any additional machining must be completed before the glass is toughened as it would shatter if it was cut in its toughened state.
In the toughening process, the surfaces of the glass are heated in a furnace. Recommended temperatures vary but the glass reaches temperatures of over 600°C. The hot glass is then cooled rapidly by a blast of air over a period of between 3 and 10 seconds. As a result, the surfaces shrink, and (at first) tensile stresses develop on the surfaces. As the bulk of the glass begins to cool, it contracts. The already solidified surfaces of the glass are then forced to contract, and consequently, they develop residual compressive surface stresses, while the interior zone develops compensating tensile stresses.
The tension zone in the core of the glass takes up about 60% of the cross-sectional area of the glass. Compressive surface stresses improve the strength of the glass in the same way that they do in other materials. The nature of the stresses is depicted in Fig. 1.
After the process the toughened glass has a greater resistance to thermal stresses and thermal shock and has improved flexural and tensile strength.
However, following characteristics remain unchanged; • Colour, • Clarity, • Chemical composition, • Light transmission, • Hardness, • Specific gravity, • Expansion coefficient, • Softening point, • Thermal conductivity, • Solar transmittance, • Stiffness.
The higher the coefficient of thermal expansion of the glass and the lower its thermal conductivity, the higher the level of residual stresses developed, and the stronger the glass becomes. Thermal toughening takes a relatively short time (minutes) and can be applied to most glasses. Because of the high amount of energy stored in residual stresses, tempered glass shatters into a large number of pieces when broken. The broken pieces are not as sharp and hazardous as those from ordinary glass.
Above is a representation of the main elements of a glass toughening facility. The size of the machinery required is dependant on the size of toughened glass parts one wishes to produce. However, for example a 1200 x 1300 mm bed which is designed for producing small parts, such as door panels would cost £140,000 + VAT (LGT Limited). This is towards the lower end of the price scale but second hand systems can be purchased for less.
Reference: Manufacturing Engineering and Technology Serope Kalpakjian
If you need some toughened glass, contact us with the details.
Return From How is Glass Made to Toughened Glass Page
more
Glass
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
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
Glass in the common sense refers to a hard, brittle, transparent, solid, such as that used for windows, many bottles, or eyewear, including, but not limited to, soda-lime glass, borosilicate glass, acrylic glass, sugar glass, isinglass (Muscovy-glass), or aluminium oxynitride.
In the technical sense, glass is an inorganic product of fusion which has been cooled to a rigid condition without crystallizing.[1][2][3][4][5] Many glasses contain silica as their main component and glass former.[6]
In the scientific sense the term glass is often extended to all amorphous solids (and melts that easily form amorphous solids), including plastics, resins, or other silica-free amorphous solids. In addition, besides traditional melting techniques, any other means of preparation are considered, such as ion implantation, and the sol-gel method.[6] However, glass science commonly includes only inorganic amorphous solids, while plastics and similar organics are covered by polymer science, biology and further scientific disciplines.
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.
The term glass developed in the late Roman Empire. It was in the Roman glassmaking center at Trier, Germany, that the late-Latin term glesum originated, probaby from a Germanic word for a transparent, lustrous substance.[7]
Contents
1 General properties, uses, occurrence
1.1 Glass in buildings
1.2 Physical applications
2 Glass production
2.1 Glass production history
2.2 Glass ingredients
2.3 Contemporary glass production
2.4 Glassmaking in the laboratory
3 Silica-free glasses
4 The physics of glass
4.1 Glass versus a supercooled liquid
4.2 Behavior of antique glass
4.3 Physical properties
4.3.1 Color
5 History
5.1 South Asia
5.2 Romans
5.3 Anglo-Saxon world
5.4 Islamic world
5.5 Medieval Europe
5.6 Late medieval Northern Europe
5.7 Murano glassmaking
6 Glass art
7 See also
8 References
9 Bibliography
10 External links
//
Borosilicate glass
Borosilicate glassware, here displayed two beakers and a test tube.
Borosilicate glass is a type of glass with the main glass-forming constituents silica and boron oxide. Borosilicate glasses are most well known for having very low coefficient of thermal expansion (~ 3 x 10-6 / C at 20oC), making them resistant to thermal shock, more so than any other common glass. Borosilicate glass was first developed by German glassmaker Otto Schott in the late 19th century[1] and sold under the brand name "Duran" in 1893. After Corning Glass Works introduced Pyrex in 1915, it became a synonym for borosilicate glass in the English-speaking world (however, since 1998 Pyrex kitchen brand is no longer made of borosilicate but of soda-lime glass[2]).
Borosilicate glassware, here displayed two beakers and a test tube.
Borosilicate glass is a type of glass with the main glass-forming constituents silica and boron oxide. Borosilicate glasses are most well known for having very low coefficient of thermal expansion (~ 3 x 10-6 / C at 20oC), making them resistant to thermal shock, more so than any other common glass. Borosilicate glass was first developed by German glassmaker Otto Schott in the late 19th century[1] and sold under the brand name "Duran" in 1893. After Corning Glass Works introduced Pyrex in 1915, it became a synonym for borosilicate glass in the English-speaking world (however, since 1998 Pyrex kitchen brand is no longer made of borosilicate but of soda-lime glass[2]).
Most borosilicate glass is clear. Colored borosilicate, for the art glass trade, was first widely brought onto the market in 1986 when Paul Trautman founded Northstar Glassworks[ citation needed ]. There are now a number of small companies in the U.S. and abroad that manufacture and sell colored borosilicate glass for the art glass market.
In addition to the quartz, sodium carbonate, and calcium carbonate traditionally used in glassmaking, boron is used in the manufacture of borosilicate glass. Typically, the resulting glass composition is about 70% silica, 10% boron oxide, 8% sodium oxide, 8% potassium oxide, and 1% calcium oxide (lime). Though somewhat more difficult to make than traditional glass (Corning conducted a major revamp of their operations to make it), it is economical to produce because its superior durability, chemical and heat resistance finds excellent use in chemical laboratory equipment, cookware, lighting, and in certain cases, windows.
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