Glass Processing and Properties_120CR0399.ppt

Glass Processing and Properties

1. Glass Processing and Properties
PRESENTED BY :
PRATYUSH KUNDU
120CR0399

2. Table of Contents
Introduction
Importance In Various Industries
Raw Materials
Glass Manufacturing Steps
Types of Glasses, their Applications
Glass Processing Techniques
Properties of Glass
Challenges and Future Trends
Conclusion

3. Introduction
Glass is amorphous material having Glass-Transition
Temperature. Glass is liquid arrested in a solid structure
and it is made by avoiding crystallization.
Its unique properties, such as transparency, hardness,
and thermal resistance, make it an essential component
in various industries ranging from construction and
automotive to electronics and household goods.

4. Importance in Various Industries
Construction Industry: Glass is extensively used in the construction of buildings and structures for
windows, doors, facades, and skylights. Its transparency allows natural light to enter interior spaces,
enhancing energy efficiency and aesthetic.
Automotive Industry: In the automotive sector, glass serves as windshields, windows, and mirrors.
Its strength, clarity, and ability to withstand impacts are crucial for ensuring driver and passenger
safety.
Electronics Industry: Glass plays a vital role in electronics manufacturing, particularly in the
production of display panels, touchscreens, and optical fibers. Its smooth surface, thermal stability,
and electrical insulation properties are highly valued in electronic devices.
Household Goods: Glassware, cookware, and light bulbs are common household items made from
glass. Its inert nature, resistance to chemical reactions, and ease of cleaning make it ideal for food
storage, cooking, and illumination.

5. Glass manufacturing materials can be divided into 5 categories:
Glass Former
Flux
Modifier
Coloring Agents
Fining Agents
Cullet(Broken glass)

6. Raw Materials
Glass Former:
One of the most important components present in any glass
Silica (SiO2),
Boric Oxide (B2O3) and
Phosphoric Oxide are the most common types of glass formers present in oxide glasses.
The use of Silica Glass is wide but melting temperature of Silica is too high (1600 -1725
deg C).
To reduce the processing temperature of Silica, different types of flux such as Na2O and
PbOcan be used.

7. The addition of fluxes to silica reduces the overall cost of glass processing but results in
degradation of properties.
Sodium Carbonate and Calcium Carbonate are common fluxes.
Potash Glass is more dense than soda glass.
To overcome this problem , different property modifiers or intermediates such as Boron
,Sodium , Magnesium ,Titanium , Calcium can be used to modify the properties of glass.
Colorantsare used to control the color in the final glass.
The amount of Iron oxide (Impurities) present in the glass results in unintentional change in
color of glass.
The other types of colorants used are gold and silver. These types of colorants change glass
color by forming colloids in glasses.

8. As the raw materials melt and react inside the furnance ,carbon dioxide and water
emission takes place which causes formation of bubbles.
Fining agents such as arsenic ,antimony oxides, potassium and sodium nitrates are
added to raw materials to remove bubbles from melt.
The high temperature and low viscosity is maintained to raise gas bubbles at upper
surface of the melt and hence removed from the melt.
Finingis important because it controls the homogeneity of glass by eliminating

9. Manufacturing Steps:

10. Batch Preparation: The process begins with the careful selection and measurement of raw materials.
The primary ingredients for glass production include silica sand, soda ash (sodium carbonate),
limestone (calcium carbonate), and cullet (recycled glass). These materials are mixed together in
precise proportions according to the desired composition of the glass.
Melting: The batch materials are fed into a furnace, typically a continuous tank furnace or a pot
furnace, where they are heated to extremely high temperatures, typically around 1500°C -1600 °C. The
intense heat causes the raw materials to melt and fuse together into a homogeneous liquid known as
molten glass.
Forming: Once the batch materials have melted, the molten glass is ready to be shaped into the
desired form.
There are several methods for forming glass, including:
-> Blowing
-> Pressing
-> Drawing

11. Refining: Once the raw materials have melted, they undergo refining to remove any impurities. This
process involves adding chemicals such as sulfur dioxide or chlorine to the molten glass, which
react with the impurities to form gases that can be removed
Annealing: After forming, the newly shaped glass undergoes an annealing process to relieve
internal stresses and strengthen the glass. The glass is gradually cooled in a controlled manner at a
carefully controlled rate to prevent cracking or distortion. Annealing typically takes place in a lehr, a
long oven with multiple temperature zones, where the glass moves slowly on a conveyor belt.
Finishing: Once the glass has been annealed, it may undergo additional processing steps to
achieve the desired surface finish and properties.
These finishing processes may include:
Cutting: Glass sheets or objects are cut to size using diamond or carbide-tipped tools.
Grinding and Polishing: The edges and surfaces of glass may be ground and polished to remove
any sharp edges or imperfections and create a smooth, glossy finish.

12. Coating: Glass surfaces may be coated with various materials such as metal oxides to
enhance properties like reflectivity, thermal insulation, or scratch resistance.
Quality Control: Throughout the manufacturing process, rigorous quality control measures
are employed to ensure that the glass meets the required specifications for strength, clarity,
and dimensional accuracy. Samples of the glass may be taken at various stages of production
for testing and analysis.
Packaging and Distribution: Once the glass has passed quality control checks, it is packaged
and prepared for distribution to customers. Depending on the application, glass may be
shipped as individual pieces, rolls, or sheets, and may undergo additional packaging to
protect it during transit.

13. Types of Glasses ,their Applications and Properties:
Soda-Lime Glass:
Composition:Soda-lime glass is the most common type of glass and is
composed of silica (sand), soda ash (sodium carbonate), and lime (calcium
oxide).
Applications: It is used in various everyday items such as windows, bottles,
containers, and tableware.
Properties:
Transparency: Soda-lime glass is transparent, allowing light to pass through.
Strength: It has moderate strength and can withstand normal handling but is
not as strong as some other types of glass.
Thermal Expansion: Soda-lime glass has a relatively high coefficient of thermal
expansion, making it susceptible to thermal stress.

14. Borosilicate Glass:
Composition: Borosilicate glass contains silica, boron trioxide, soda ash, and
alumina.
Applications: It is commonly used in laboratory glassware, cookware, lighting
fixtures, and high-temperature applications.
Properties:
Thermal Resistance: Borosilicate glass has excellent thermal shock resistance
and can withstand rapid temperature changes without breaking.
Chemical Resistance: It is highly resistant to chemical corrosion, making it
suitable for use in harsh environments.
Transparency: Borosilicate glass is transparent and has a low refractive index.

15. Tempered Glass:
Composition: Tempered glass is typically soda-lime glass that has undergone a
special heat treatment process.
Applications: It is used in applications where safety is a concern, such as
automotive windows, shower doors, and glass doors and partitions.
Properties:
Strength: Tempered glass is significantly stronger than untreated glass and can
withstand higher impact forces.
Safety: When tempered glass breaks, it shatters into small, relatively harmless
fragments instead of sharp, jagged shards.
Thermal Resistance: Tempered glass has improved thermal resistance
compared to untreated glass but may still be susceptible to thermal stress.

16. Laminated Glass:
Composition: Laminated glass consists of two or
more layers of glass bonded together with an interlayer
of polyvinyl butyral (PVB) or ethylene-vinyl acetate (EVA).
Applications: It is used in safety glazing applications
such as automotive windshields, building facades,
and glass floors.
Properties:
Safety: Laminated glass provides enhanced safety as the interlayer holds
the glass together when broken, reducing the risk of injury from flying
shards.
Sound Insulation: It offers improved sound insulation compared to
monolithic glass, making it suitable for noise-sensitive environments.
UV Protection: Laminated glass can be manufactured with UV-blocking
interlayers to protect against UV radiation.

17. Glass Processing Techniques
Thermal Processing:
Annealing:
Process:Annealing involves heating the glass to a high temperature and then slowly cooling it to
relieve internal stresses. This process helps to reduce the likelihood of spontaneous breakage and
improves the overall strength and durability of the glass.
Applications: Annealing is commonly used in the manufacturing of flat glass, such as window panes
and mirrors, as well as in the production of glassware and other glass products.

18. Tempering:
Process: Tempering involves heating the glass to a high temperature and then rapidly cooling it using air jets or
quenching in a controlled manner. This process creates surface compression and edge tension, resulting in
increased strength and resistance to impacts.
Applications:Tempered glass is widely used in applications where safety is a concern, such as in automotive
windows, shower doors, glass partitions, and tabletops.
Heat Strengthening:
Process: Heat strengthening is similar to tempering but involves a slower cooling process, resulting in lower
surface compression and edge tension compared to tempered glass. While not as strong as tempered glass,
heat-strengthened glass still offers improved strength and resistance to thermal stress.
Applications: Heat-strengthened glass is commonly used in architectural applications such as windows, doors,
and glass facades where increased strength and resistance to thermal stress are required.

19. Acid Etching:
Process: Acid etching involves applying an acidic solution, such as hydrofluoric
acid, to the surface of the glass to create a frosted or matte finish. The acid reacts
with the glass surface, creating a rough texture that diffuses light.
Applications: Acid etching is often used for decorative purposes in glassware,
shower doors, windows, and architectural glass panels to enhance privacy or
aesthetics.
Surface Coatings:
Process: Surface coatings involve applying thin layers of materials such as metal
oxides or polymers to the surface of the glass to alter its properties. Coatings can
provide benefits such as improved scratch resistance, UV protection, glare
reduction, or enhanced thermal insulation.
Applications: Coated glass is used in a wide range of applications, including
automotive windshields, architectural glass, and electronic displays, to improve
performance and durability.
Acid Etched glass

20. Mechanical Processing
Cutting:
Process: Cutting involves using specialized tools such as diamond or carbide-tipped blades
to score and break the glass along desired lines. Various cutting techniques, including
straight cutting, curved cutting, and shape cutting, are employed to achieve precise shapes
and sizes.
Applications: Cutting is a fundamental process in glass fabrication used to produce glass
sheets, panels, windows, and custom glass components for various applications.
Grinding:
Process: Grinding involves using abrasive materials to remove material from the surface of
the glass, resulting in a smooth and uniform finish. Grinding can be used to remove sharp
edges, surface imperfections, or to achieve precise dimensions.
Applications: Grinding is commonly used in the fabrication of optical components, lenses,
mirrors, and glass sculptures to achieve high precision and surface quality.

21. Polishing:
Process: Polishing involves buffing the surface of the glass using fine abrasives to
create a glossy, reflective finish. Polishing removes any remaining surface
imperfections or scratches left from cutting or grinding processes.
Applications: Polishing is used in the production of high-end glass products such
as optical lenses, mirrors, decorative glassware, and precision instruments to
enhance aesthetics and optical clarity.
Drilling:
Process: Drilling involves using specialized diamond or carbide drill bits to create
holes in the glass. The drilling process requires careful control of speed, pressure,
and coolant to prevent cracking or chipping of the glass.
Applications: Drilling is essential for installing hardware, fittings, and accessories
in glass panels, windows, doors, and architectural glass structures.
Glass Polishing

22. Properties of Glass
OpticalProperties
Transparency:
Glass is transparent to visible light, allowing light to pass through without significant absorption or
scattering. This property makes glass suitable for applications requiring visibility, such as windows, lenses,
and optical instruments.
Refractive Index:
The refractive index of glass determines how light propagates through it. It is a measure of how much light
is bent or refracted as it enters the glass from air. Different types of glass have varying refractive indices,
influencing their optical performance in lenses, prisms, and other optical components.
Dispersion:
Dispersion refers to the splitting of light into its component colors (rainbow effect) as it passes through a
material. While glass generally exhibits some degree of dispersion, certain types of glass, such as optical
glasses used in lenses and prisms, are engineered to minimize or maximize dispersion based on specific
applications.

23. Mechanical Properties
Strength:
The strength of glass refers to its ability to withstand applied forces without breaking or deforming.
Various factors, including composition, surface treatments, and manufacturing processes, influence the
strength of glass. Tempered glass, for example, is significantly stronger than regular glass due to its
thermal treatment process.
Toughness:
Toughness is the ability of glass to absorb energy without fracturing. While glass is inherently brittle,
certain types, like laminated glass, exhibit improved toughness due to the interlayer that holds the glass
together upon impact. Toughened or tempered glass also demonstrates increased toughness compared
to untreated glass.
Elasticity:
Elasticity refers to the ability of glass to deform under stress and return to its original shape once the
stress is removed. While glass is not as elastic as metals or polymers, it does exhibit some degree of
elasticity, especially under low-stress condition

24. Thermal Properties
Thermal Conductivity:
Thermal conductivity measures the ability of glass to conduct heat. Glass is a poor
conductor of heat compared to metals, making it useful for thermal insulation in
windows and building materials. However, thermal conductivity varies among different
types of glass, with borosilicate glass exhibiting higher thermal conductivity than soda-
lime glass.
Coefficient of Thermal Expansion (CTE):
CTE quantifies how much a material expands or contracts with changes in temperature.
Glass has a relatively low CTE, but it varies depending on the composition and
manufacturing process. This property is critical in applications where dimensional
stability is essential to prevent cracking or distortion due to thermal stress.

25. Chemical Properties
Resistance to Corrosion:
Glass is generally resistant to chemical corrosion from most acids, bases, and solvents.
However, certain aggressive chemicals or conditions may lead to glass corrosion or
etching over time. Borosilicate glass, in particular, exhibits high resistance to chemical
corrosion, making it suitable for laboratory glassware and chemical storage containers.
Chemical Stability:
Glass is chemically stable under normal environmental conditions, maintaining its
integrity and properties over time. This property ensures that glass maintains its
transparency, strength, and other desirable characteristics even after prolonged exposure
to the elements or harsh chemical environments.

26. Applications of Processed Glass
Architectural Glass:
Windows: Glass windows are essential components of buildings, providing natural light,
ventilation, and aesthetic appeal. They come in various types, including single-pane, double-
pane, and energy-efficient windows.
Facades: Glass facades, also known as curtain walls, are exterior building envelopes made
primarily of glass panels. They offer transparency, insulation, and architectural elegance,
commonly used in modern skyscrapers and commercial buildings.
Skylights: Skylights are glass windows installed on roofs to allow natural light into interior
spaces. They enhance daylighting, reduce the need for artificial lighting, and create a
connection to the outdoors in residential and commercial buildings.
Automotive Glass:
Windshields: Automotive windshields are laminated safety glass designed to protect
occupants from wind, debris, and collisions. They provide structural support to the vehicle and
support the deployment of airbags during accidents.
Windows: Side and rear windows in vehicles are typically made of tempered glass to ensure
safety in case of breakage. They provide visibility, insulation, and protection from the
elements.
Mirrors: Automotive mirrors, including rearview mirrors and side mirrors, are essential for
driver visibility and safety. They are made of reflective glass coated with metal layers to
enhance reflectivity.

27. Electronics:
Display Panels: Glass is a common substrate material for display panels in electronic devices such as
televisions, monitors, and smartphones. It provides a smooth surface for displaying images and protects
the underlying electronic components.
Touchscreens: Glass touchscreens enable user interaction with eletronicdevices through touch gestures.
They offer durability, scratch resistance, and high clarity, making them suitable for smartphones, tablets
Household Item:
Glassware: Glassware includes various items such as drinking glasses, bowls, plates, and vases
made from processed glass. They are used for serving food and beverages, decorative purposes,
and storage.
Cookware: Glass cookware, such as baking dishes and casserole dishes, is oven-safe, non-reactive,
and easy to clean. It is ideal for baking, roasting, and serving hot dishes.
Light Bulbs: Incandescent, fluorescent, and LED light bulbs often contain glass components such
as bulbs or tubes. Glass bulbs provide a protective enclosure for the lighting elements and help to
diffuse and transmit light effectively.

28. Challenges and Future Trends
Challenges
Environmental Impact of Glass Processing:
Glass processing involves high energy consumption and emissions of greenhouse gases,
contributing to environmental pollution and climate change. The extraction of raw materials, such
as silica sand and soda ash, also poses environmental concerns, including habitat destruction and
depletion of natural resources.
Waste Management:
Glass production generates significant amounts of waste, including offcuts, scrap glass, and
emissions from manufacturing processes. Proper waste management and recycling are essential to
minimize environmental impact and promote sustainability in the glass industry.
Energy Efficiency:
The glass industry is energy-intensive, requiring large amounts of heat for melting raw materials
and shaping glass products. Improving energy efficiency through the adoption of advanced
technologies and process optimization is crucial for reducing greenhouse gas emissions and
conserving energy resources.

29. Future Trends
Emerging Technologies in Glass Processing:
The glass industry is continuously evolving with the adoption of advanced technologies to enhance
product quality, efficiency, and sustainability. Some emerging trends include:
Industry 4.0: Integration of digital technologies such as automation, artificial intelligence, and data
analytics to optimize production processes, improve quality control, and reduce resource
consumption.
Additive Manufacturing (3D Printing): Exploring additive manufacturing techniques to fabricate
complex glass structures and customized products with minimal material waste.
Smart Glass: Development of smart glass technologies, including electrochromic, thermochromic,
and photochromic glass, for dynamic control of light transmission, thermal insulation, and privacy.
Bioinspired Materials: Drawing inspiration from nature to design novel glass compositions with
enhanced properties such as self-cleaning surfaces, anti-fogging coatings, and biodegradability.

30. Conclusion
Importance of Understanding Glass Processing for Various Industries:
Understanding glass processing is crucial for various industries, including construction, automotive,
electronics, and household goods, for the following reasons:
Safety and Durability: Proper glass processing techniques ensure the safety and durability of glass
products, especially in applications where strength and resistance to impacts are critical, such as
automotive windshields and architectural glass.
Functionality and Aesthetics: Glass processing enables the customization of glass products to meet
specific functional and aesthetic requirements, enhancing their performance and visual appeal in
diverse applications.
Innovation and Sustainability: By embracing sustainable manufacturing practices and adopting
advanced processing technologies, the glass industry can drive innovation, reduce environmental
impact, and create opportunities for sustainable growth.
In this presentation, we've explored the world of glass processing, covering its manufacturing
techniques, properties, challenges, and future trends.

31. Thank you !
PRESENTED BY:
PRATYUSH KUNDU
120CR0399
FINAL YEAR, 8
th
SEMESTER