Lesson Notes By Weeks and Term - Junior Secondary 3

TERM – 3^RD TERM

WEEK FIVE

Class: Junior Secondary School 3

Age: 14 years

Duration: 40 minutes of 5 periods each

Date:

Subject: BASIC TECHNOLOGY

Topic: PROCESSING OF MATERIALS –CERAMICS AND GLASS

SPECIFIC OBJECTIVES: At the end of the lesson, pupils should be able to

1. Identify the methods of production of ceramics
2. Identify the uses of ceramics
3. Identify the methods of production of glass
4. Identify the uses of glass

INSTRUCTIONAL TECHNIQUES: Identification, explanation, questions and answers,

demonstration, videos from source

INSTRUCTIONAL MATERIALS: Videos, loud speaker, textbook, pictures,

INSTRUCTIONAL PROCEDURES

PERIOD 1-2

NOTE

PROCESSING OF MATERIALS –CERAMICS AND GLASS

Ceramics

 The production of ceramics involves several methods, each tailored to specific types of ceramics and desired characteristics. Here are some common methods of ceramic production:

1. Removal of Clay: This method involves extracting raw clay from the earth, typically through mining or excavation. The clay is then processed to remove impurities, rocks, and other unwanted materials.

The purified clay is prepared for shaping through various techniques.

2. Moulding Clay: Once the clay is prepared, it can be shaped into the desired form through different molding techniques.

   - Hand molding involves manually shaping the clay, while wheel throwing uses a rotating wheel for precision.

   - Other methods include slip casting, press molding, and extrusion, each offering distinct possibilities for creating ceramic objects.

3. Firing: Firing is a crucial step where shaped clay undergoes high-temperature treatment in a kiln. Bisque firing is the initial firing to harden the clay, making it more durable for subsequent glazing.

   - Glaze firing follows, during which a glaze is applied to the ceramic surface, creating the final aesthetic and protective layer.

4. Decoration: Ceramic pieces can be decorated in various ways to enhance their visual appeal. Techniques include glazing, painting, carving, sgraffito (scratching designs into the surface), and applying decals.

 Decorations not only add artistic elements but can also serve functional purposes, such as creating textured surfaces or highlighting specific features of the ceramic piece.

Uses of ceramics

Ceramics have a wide range of uses across various industries due to their unique properties, which include heat resistance, hardness, electrical insulation, and chemical inertness. Here are some common uses of ceramics:

1. Ceramics are widely used in the production of dishes, plates, bowls, and kitchen utensils due to their durability and heat resistance.
2. Tiles and bricks made from ceramics are used for flooring, walls, and roofs in both residential and commercial buildings.
3. Ceramics are integral to the electronics industry, being used in the production of insulators, capacitors, resistors, and substrates for electronic components.
4. Traditional pottery and ceramic art pieces are created for aesthetic purposes, including sculptures, vases, and decorative tiles.
5. Ceramic materials are used for cutting tools, grinding wheels, and bearings due to their hardness and wear resistance.
6. Ceramics are present in everyday items like coffee mugs, flower pots, and decorative tiles.

Glass

The production of glass involves several methods, primarily focusing on the transformation of raw materials into molten glass and then shaping and cooling it to create the final product. Here are the main methods of glass production:

1. Batching: Raw materials such as silica sand, soda ash, and limestone are precisely measured and mixed to create a batch of glass.
2. Melting: The batch is melted in a furnace at high temperatures (around 1700°C or 3092°F) to form molten glass. This process may take several hours to achieve a homogeneous melt.
3. Forming: The molten glass is shaped into the desired form using various methods, including:

     - Blown Glass: Molten glass is gathered on the end of a blowpipe, and the glassblower shapes it by blowing air into the pipe.

     - Float Glass: Molten glass is poured onto a bath of molten tin, creating a smooth and flat surface.

     - Sheet Glass: Molten glass is rolled into sheets between large metal rollers.

     - Container Glass: Molten glass is formed into bottles or jars using molds.

4. Annealing: The formed glass undergoes an annealing process, where it is slowly cooled in an annealing oven. This gradual cooling relieves internal stresses and enhances the glass's strength and durability.
5. Cutting and Finishing: Once the glass is annealed, it can be cut, polished, or otherwise finished according to the desired product. This includes cutting sheets into specific sizes or shaping glass containers.
6. Coating and Decorating: Glass may undergo additional processes for coating or decorating, such as applying coatings for UV protection, adding decorative patterns, or applying colored coatings.
7. Tempering (for Tempered Glass): Tempered glass is subjected to a special heat treatment that imparts increased strength and safety. When broken, tempered glass shatters into small, relatively harmless fragments.

Uses of Glass

Glass is a versatile material with a wide range of applications due to its transparency, durability, and adaptability. Here are some common uses of glass across various industries:

1. Construction and Architecture: Glass is a fundamental component of windows and doors providing natural light and insulation.
2. Containers and Packaging: Glass containers are commonly used for storing food and beverages due to their non-reactive nature and impermeability.
3. Automotive Industry: Laminated glass is used in car windshields for safety, while tempered glass is used in side and rear windows.
4. Electronics: Glass is a key component in electronic devices such as smartphones, tablets, and computer monitors.
5. Tableware and Kitchenware: Glass is a common material for drinking glasses and cups. Some cookware, like baking dishes and casserole dishes, is made from glass.
6. Medical Applications: Glass is widely used for laboratory glassware, including beakers, test tubes, and petri dishes.
7. Home Decor and Furniture: Glass mirrors are used for personal grooming and interior design.
8. Lighting: Incandescent and LED light bulbs use glass envelopes to protect the filament or LED elements.
9. Art and Design: Used in artistic and religious contexts for creating colorful and intricate designs.

EVALUATION: 1. Discuss the steps for processing ceramics.

2. Identify 5 uses of ceramics
3. Mention and describe all steps in glass production.

CLASSWORK: As in evaluation

CONCLUSION: The teacher commends the students positively