Processing of Materials – Ceramics and Glass

Subject: Basic Technology
Class: JSS 3
Term: First Term
Week: 7
Age: 12-15 years
Topic: Processing of Materials – Ceramics and Glass
Sub-topic: Methods, Production, and Uses
Duration: 60 minutes

Behavioural Objectives

By the end of the lesson, students should be able to:

1. Define ceramics and glass.
2. Explain the methods of producing ceramics and glass.
3. Identify various uses of ceramics and glass materials.
4. List examples of ceramics and glass products used in daily life.

Keywords

• Ceramics
• Glass
• Kiln
• Molding
• Glazing
• Annealing

Set Induction

The teacher displays common ceramic and glass items such as plates, mugs, mirrors, and windows, asking students to identify their materials.

Entry Behaviour

Students are familiar with common household items made from ceramics and glass, such as plates and glass windows.

Learning Resources and Materials

• Samples of ceramic products (plates, mugs)
• Glass objects (mirrors, bottles)
• Pictures or videos showing the production process of ceramics and glass

Building Background/Connection to Prior Knowledge

Remind students of previous lessons on wood and metal processing. Now, they will explore other important materials – ceramics and glass – which also have practical applications.

Embedded Core Skills

• Critical thinking and observation
• Practical knowledge of material production
• Environmental awareness

Learning Materials

• Sample ceramics and glass objects
• Charts showing the production stages
• Videos demonstrating the firing and annealing process

Reference Books

• Lagos State Scheme of Work
• Basic Technology Textbook for JSS 3
• Processing of Materials Handbook by O. Adediran

Instructional Materials

• Ceramic plates, glass bottles
• Visual aids or posters of the production stages
• Safety gear for handling glass materials

Content

I. Definition of Ceramics and Glass

• Ceramics: Non-metallic, inorganic materials made by shaping and firing clay or other minerals at high temperatures.
• Glass: A hard, transparent material made from sand (silica), soda ash, and limestone, melted and cooled to form a solid structure without crystals.

II. Methods of Producing Ceramics and Glass

A. Ceramic Production Process

1. Preparation of Clay: Collecting and refining clay to remove impurities.
2. Shaping/Molding: Shaping the clay using molds or on a potter’s wheel.
3. Drying: Allowing the shaped items to air dry before firing.
4. Firing in a Kiln: Heating the dried items in a kiln at temperatures between 1,000°C and 1,400°C to harden them.
5. Glazing: Applying a glass-like coating for decoration and waterproofing.
6. Second Firing: Re-firing glazed ceramics to fix the glaze.

B. Glass Production Process

1. Mixing Raw Materials: Silica (sand), soda ash, and limestone are mixed.
2. Melting: The mixture is melted in a furnace at around 1,700°C.
3. Shaping: The molten glass is shaped using molds or blown into the desired form.
4. Annealing: Gradually cooling the shaped glass to prevent cracking.
5. Finishing: Cutting, polishing, or coating the glass for final use.

III. Uses of Ceramics and Glass

Uses of Ceramics

1. Plates, cups, and bowls used in homes.
2. Tiles for flooring and walls.
3. Sanitary ware such as toilets and sinks.
4. Electrical insulators.
5. Artistic items such as sculptures and pottery.

Uses of Glass

1. Windows and mirrors.
2. Bottles and jars for packaging.
3. Eyeglasses and lenses.
4. Decorative items such as chandeliers.
5. Laboratory equipment like test tubes and beakers.

Evaluation (Fill-in-the-Blank Questions)

1. __________ is made by shaping and firing clay at high temperatures.
   (a) Glass (b) Metal (c) Ceramics (d) Plastic
2. The machine used for firing ceramics is called a __________.
   (a) kiln (b) oven (c) furnace (d) heater
3. __________ is the raw material primarily used in making glass.
   (a) Clay (b) Silica (c) Wood (d) Limestone
4. A __________ process cools glass slowly to prevent cracking.
   (a) glazing (b) drying (c) annealing (d) molding
5. __________ are used for packaging beverages.
   (a) Ceramic plates (b) Glass bottles (c) Plastic bags (d) Metal cans
6. __________ is applied to ceramics to create a smooth, shiny surface.
   (a) Paint (b) Varnish (c) Glaze (d) Sandpaper
7. Windows are typically made from __________.
   (a) ceramic (b) metal (c) plastic (d) glass
8. __________ is a use of ceramics in construction.
   (a) Beakers (b) Tiles (c) Mirrors (d) Lenses
9. The process of shaping ceramics on a wheel is called __________.
   (a) annealing (b) molding (c) glazing (d) throwing
10. A __________ furnace melts raw materials for making glass.
    (a) kiln (b) glass-blowing (c) blast (d) electric

Class Activity Discussion (FAQs)

1. What is ceramic?
   Ceramics are materials made from fired clay or other minerals.
2. How is glass made?
   Glass is made by melting silica, soda ash, and limestone in a furnace.
3. What is glazing in ceramics?
   Glazing involves applying a glass-like coating to ceramics for waterproofing.
4. Why is annealing important in glass production?
   It prevents glass from cracking during cooling.
5. What are the main uses of ceramics?
   Ceramics are used for plates, tiles, sanitary ware, and electrical insulators.
6. What are the raw materials for making glass?
   Sand (silica), soda ash, and limestone are the primary materials.
7. What is a kiln?
   A kiln is a high-temperature oven used to fire ceramics.
8. Can ceramics be recycled?
   Yes, but it’s a complex process.
9. How are glass bottles produced?
   By blowing molten glass into molds.
10. What is the difference between ceramics and glass?
    Ceramics are made from clay and hardened by heat, while glass is made by melting silica and cooling it into a solid form.

Teacher’s Activities

1. Demonstrate the steps of making ceramics and glass using diagrams or videos.
2. Show real-life ceramic and glass products and explain their production processes.
3. Guide students to identify different uses of ceramics and glass.

Learners’ Activities

1. Observe and describe various ceramics and glass objects.
2. Participate in discussions about the production and uses of the materials.
3. Answer evaluation questions based on the lesson.

Evaluation Questions

1. Define ceramics and glass.
2. List the raw materials used in making glass.
3. Explain the purpose of annealing in glass production.
4. What is glazing in ceramics?
5. Mention three uses of ceramics.
6. Name two common glass products.
7. What equipment is used to fire ceramics?
8. State the first step in producing ceramics.
9. Why is silica important in glass production?
10. Differentiate between molding and blowing in production processes.

Conclusion

The teacher inspects students’ understanding through their answers and gives feedback.