Glass Industry. GLASS, CERAMICS AND RELATED MATERIALS GLASS, CERAMICS AND RELATED MATERIALS glass...

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Transcript of Glass Industry. GLASS, CERAMICS AND RELATED MATERIALS GLASS, CERAMICS AND RELATED MATERIALS glass...

  • Slide 1
  • Glass Industry
  • Slide 2
  • GLASS, CERAMICS AND RELATED MATERIALS GLASS, CERAMICS AND RELATED MATERIALS glass glass synthetic vitreous fibres synthetic vitreous fibres pottery pottery ceramic tile ceramic tile industrial ceramics industrial ceramics brick and tile refractories synthetic gems optical fibres.
  • Slide 3
  • Common Processes and Hazards Batch raw material processes Batch raw material processes Firing or melting processes Firing or melting processes Material handling in production, fabrication, packaging and warehousing Material handling in production, fabrication, packaging and warehousing Rebuilds and reconstruction activities Rebuilds and reconstruction activities
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  • Definition an inorganic product of fusion that has cooled to a rigid condition without crystallizing an inorganic product of fusion that has cooled to a rigid condition without crystallizing When glass is cooled from the hot molten state, it gradually increases in viscosity without crystallization over a wide temperature range, until it assumes its characteristic hard, brittle form. Cooling is controlled to prevent crystallization, or high strain. When glass is cooled from the hot molten state, it gradually increases in viscosity without crystallization over a wide temperature range, until it assumes its characteristic hard, brittle form. Cooling is controlled to prevent crystallization, or high strain.
  • Slide 5
  • Glass, chemically, is actually more like a liquid, but at room temperature it is so viscous or 'sticky' it looks and feels like a solid. At higher temperatures glass gradually becomes softer and more like a liquid. It is this latter property which allows glass to be poured, blown, pressed and moulded into such a variety of shapes. Glass, chemically, is actually more like a liquid, but at room temperature it is so viscous or 'sticky' it looks and feels like a solid. At higher temperatures glass gradually becomes softer and more like a liquid. It is this latter property which allows glass to be poured, blown, pressed and moulded into such a variety of shapes.
  • Slide 6
  • History Glass technology has evolved for 6,000 years Glass technology has evolved for 6,000 years A most important development in glass technology was the use of a blow pipe A most important development in glass technology was the use of a blow pipe The first glass was coloured because of the presence of various impurities such as oxides of iron and chromium. Virtually colourless glass was first made some 1,500 years ago. The first glass was coloured because of the presence of various impurities such as oxides of iron and chromium. Virtually colourless glass was first made some 1,500 years ago. Today many products of glass are made in fully automatic processing lines Today many products of glass are made in fully automatic processing lines Although glass is one of the oldest materials, its properties are unique and not yet fully understood. Although glass is one of the oldest materials, its properties are unique and not yet fully understood.
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  • Applications Chemistry Chemistry Pharmacy Pharmacy Electrical and electronics industries Electrical and electronics industries Optics industries Optics industries Construction and lighting industries Construction and lighting industries
  • Slide 8
  • Major constituents Silica sand Silica sand Soda ash Soda ash Lime stone Lime stone Dolomite Dolomite Feldspathic materials Feldspathic materials Lead oxide Lead oxide Boric acid Boric acid Crushed glass Crushed glass
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  • Minor constituents The remainder of the batch consists of several additional ingredients, chosen from a group of some 15 to 20 materials commonly referred to as minor ingredients. The remainder of the batch consists of several additional ingredients, chosen from a group of some 15 to 20 materials commonly referred to as minor ingredients. These latter additions are added with a view to providing some specific function or quality, such as colour, which is to be realized during the glass preparation process. These latter additions are added with a view to providing some specific function or quality, such as colour, which is to be realized during the glass preparation process.
  • Slide 10
  • Common glasses Soda-lime-silica glass (commercial glass) Soda-lime-silica glass (commercial glass) Lead-potash-silica glass Lead-potash-silica glass Borosilicate glass Borosilicate glass
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  • Soda-lime-silica glass SiO2 (silica) 70% Na2O (sodium oxide)12% CaO (calcium oxide) 8% MgO (magnesium oxide) 3% Al2O3 (aluminium oxide) 1% SiO2 (silica) 70% Na2O (sodium oxide)12% CaO (calcium oxide) 8% MgO (magnesium oxide) 3% Al2O3 (aluminium oxide) 1% Commercial glass is colourless Commercial glass is colourless Additional chemicals have to be added to produce different colours of glass such as green, blue or brown glass. Additional chemicals have to be added to produce different colours of glass such as green, blue or brown glass.
  • Slide 12
  • Lead-potash-silica glass It is made by using lead oxide instead of calcium oxide, and potassium oxide instead of all or most of the sodium oxide It is made by using lead oxide instead of calcium oxide, and potassium oxide instead of all or most of the sodium oxide High refractive index High refractive index Relatively soft surface Relatively soft surface High electrical resistivity High electrical resistivity Radiation protection (h igher lead oxide contents typically 65%absorb gamma rays and other forms of harmful radiation) Radiation protection (h igher lead oxide contents typically 65%absorb gamma rays and other forms of harmful radiation)
  • Slide 13
  • Borosilicate glass silica (70-80%) and boric oxide (7-13%) with smaller amounts of the alkalis (sodium and potassium oxides) and aluminium oxide. silica (70-80%) and boric oxide (7-13%) with smaller amounts of the alkalis (sodium and potassium oxides) and aluminium oxide. ovenware and other heat-resisting ware (Pyrex) ovenware and other heat-resisting ware (Pyrex)
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  • Types of special glass include : Vitreous silica Vitreous silica Aluminosilicate glass Aluminosilicate glass Alkali-barium silicate glass Alkali-barium silicate glass Technical glass Technical glass Glass ceramics Glass ceramics Opical glass Opical glass Sealing glass Sealing glass
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  • Glass making Pot process Pot process Tank process Tank process
  • Slide 16
  • Pot Process The manufactured of high quality glass such as optical and mirror glass & small quantities of specialty glass The manufactured of high quality glass such as optical and mirror glass & small quantities of specialty glass Hazard of hand shoveling & filling of the pots Hazard of hand shoveling & filling of the pots Optical and specialty glasses contain heavy metals (lead, barium and manganese) Optical and specialty glasses contain heavy metals (lead, barium and manganese)
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  • Pot Furnace
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  • Tank Process Permits enclosed &continuous feeding of bath ingredient (reduced dust exposure) Permits enclosed &continuous feeding of bath ingredient (reduced dust exposure) Refractory blocks and bricks used in the construction of the furnaces and tanks contain free silica. Refractory blocks and bricks used in the construction of the furnaces and tanks contain free silica.
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  • Tank Furnace
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  • Slide 21
  • Glass objects formed by: Blowing Blowing Pressing Pressing Casting Casting Rolling Rolling Drawing Drawing Floating Floating
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  • The blow pipe
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  • Pressing & Blowing
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  • Continuous float process
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  • Ribbon of float glass exiting from lehr after being annealed Ribbon of float glass exiting from lehr after being annealed
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  • Glass additive Accelerate melting Accelerate melting Stabilizer Stabilizer Improved optical properties Improved optical properties Remove bubbles Remove bubbles Color Color
  • Slide 27
  • Accelerate melting Fluorine Fluorine Calcium fluoride Calcium fluoride Sodium silicafluoride Sodium silicafluoride
  • Slide 28
  • Stabilizers Increased resistance Increased resistance Barium, Lead, Ca, Mg,Zn oxides Barium, Lead, Ca, Mg,Zn oxides
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  • Improved optical properties Rare earth metals Rare earth metals Thorium Thorium
  • Slide 30
  • Remove bubbles Salts of arsenic Salts of arsenic antimony antimony
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  • Color Salts of chromium ( green yellow) Salts of chromium ( green yellow) cobalt (red blue ) cobalt (red blue ) cadmium (yellow) cadmium (yellow) manganese manganese nickel (black) nickel (black) selenium ( red) selenium ( red)
  • Slide 32
  • Potential health and safety hazards found during manufacturing of glass, ceramic and related materials
  • Slide 33
  • Ergonomic stressors; biomechanical hazards Ergonomic stressors; biomechanical hazards Uses or sources of exposure to hazard Potential effects (physical hazards or health effects) Precautions or control strategies Overexertion from manual mater