1. Glass
Topic 4.2c

2. Nature of Design DO NOT NEED TO WRITE THIS!
The rapid pace of technological discoveries is very evident in the manufacture and use of glass in electronic devices. Different properties have presented in glass for aesthetic or safety considerations for many years but the future of glass seems to be interactivity alongside electronic systems. The structure of glass is not well understood, but as more is learned, its use is becoming increasingly prominent in building materials and structural applications.
Nature of Design

3. Characteristics of Glass
Commercial glass is mostly made of sand. Using degrees over degrees Celsius.
In order to reduce the energy requirements, other materials are added to sand to reduce the temperature of fusion.
Characteristics of Glass

4. Characteristics of Glass
Glasses may be devised to meet almost any imaginable requirement.
Used for many specialized applications in chemistry, pharmacy, electrical industries, optics, and construction industry.
Like other ceramics, glasses are brittle.
Characteristics of Glass

5. Types of Glass Glass fiber (fiberglass) Lead glass (crystal)
Soda-lime glass (commercial)
Borosilicate glass (Pyrex)
Laminated glass (safety glass)
Tempered glass
Types of Glass

6. The lack of reactivity with most chemicals makes glass an ideal material for storage
One of the unique characteristics of glass is its ability to allow light to be transmitted with minimal scattering, allowing a clear view through it.
Transparency
Chemically Inert
Characteristics

7. The lack of reactivity shown by glass and the absence of toxic breakdown products has led to the extensive use for food storage.
Glass resists scratching under normal conditions of handling and cleaning, leading to long service with minimal degradation.
Non-Toxic
Hardness
More Characteristics

8. Even More Characteristics
When molten, glass is extremely plastic, allowing it to be formed, drawn, blown and joined into any imaginable shape.
Brittle
Aesthetic Appeal
Even More Characteristics
The main drawback with glass is that it can be brittle and inflexible.
Developments such as laminated glass and toughened glass reduce the risk of breaking.

9. The high volume of production, abundant raw materials, and ability to recycle glass make it relatively cheap to produce.
Glass is an excellent electrical insulator and because of this has found extensive use as an insulator on high voltage overhead electrical transmission lines.
Electrical Insulator
Cheap
Last Characteristics

10. The stability, inertness, and transparency of glass sees its widespread use in windows, food and chemical containers, lighting, and lenses.
Glass does not absorb any materials.
Applications of Glass

11. A material consisting of numerous extremely fine fibers of glass.
Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with finer machine tooling.
Glass Fiber

12. Lead Glass Commonly called crystal.
A variety of glass in which lead replaces the calcium content of a typical glass.
Lead oxide added to molten glass gives lead crystal a much greater ‘sparkle’ by increasing specular reflection.
Lead Glass

13. Soda-Lime Glass The most prevalent type of glass.
Used for windowpanes and glass containers for food and beverages.
Accounts for 90% of manufactured glass.
Soda-Lime Glass

14. A type of glass with silica and boron trioxide as the main constituents.
Known for having very low coefficients of thermal expansion.
Has a wide variety of uses including cookware, lab equipment, and medical devices.
Borosilicate Glass

15. Laminated Glass Type of safety glass that holds together when broken.
In the event of breaking, it is held together by an interlayer between two or more layers of glass.
Laminated Glass

16. Type of safety glass that is controlled through thermal treatment to increase its strength compared to normal glass.
Tempering puts outer surfaces into compression and the interior into tension.
These stresses cause the glass, when broken, to crumble into granular chunks instead of large jagged pieces.
Tempered Glass

17. Recovery and Disposal of Glass
Recycled glass, known as cullet, is used to make new glass.
Glass is grouped and sorted by color, before being crushed into fine pieces.
Once crushed, cullet can be re-melted and manufactured into new glass containers.
Because it is so expensive, the United States does not recycle glass.
Recovery and Disposal of Glass

18. Uses