PRODUCTION OF SYNTHETIC FABRICS
Subject:
Home Economics
Term:
First Term
Week:
Week 11
Class:
JSS 3 / BASIC 9
Previous lesson: Pupils have previous knowledge of
Manufacturing Process of Linen
that was taught in their previous lesson
Topic:
PRODUCTION OF SYNTHETIC FABRICS
Behavioural objectives: At the end of the lesson, the pupils should be able to
- define synthetic fabrics
- explain the process of synthetic fabrics
- give examples of synthetic fabrics
Instructional Materials:
- Wall charts
- Pictures
- Related Online Video
- Flash Cards
Methods of Teaching:
- Class Discussion
- Group Discussion
- Asking Questions
- Explanation
- Role Modelling
- Role Delegation
Reference Materials:
- Scheme of Work
- Online Information
- Textbooks
- Workbooks
- 9 Year Basic Education Curriculum
- Workbooks
Content:
PRODUCTION OF SYNTHETIC FABRICS
PRODUCTION OF SYNTHETIC Fabrics.
Manufacturing Process of Rayon Viscose rayon is obtained from the cellulose of wood pulp or cotton linter.
The steps involved are as follows:
(i) Purification: The cellulose (wood pulp or cotton linters) is first purified.
(ii) Acid treatment: The cellulose is then treated with the right chemicals. E.g. caustic soda and carbon-disulphide to form a thick thread-like liquid.
(iii) Spinning: The liquid is then forced through a nozzle containing many fine holes called the rayon filament or fibres are produced.
(iv) Delustering: This is the process of adding a white pigment powder into the spinning solution so that the filament will not have metallic luster.
(v) Dyeing: This may be carried out after the yarn is spun or the dye can be added to the spinning solution.
(vi) Weaving: The spun yarn is woven into a fabric in the process called weaving.Spinneret with filaments.
Manufacturing Procedure of Acetate
(i) The cellulose is purified.
(ii) It is treated with acetic acid and acetic anhydride, then with water. Cellulose acetate is formed.
(iii) Cellulose acetate is dissolved in acetone to form a thick liquid.
(iv) The liquid is spun into filaments or fibres.
Manufacturing of Nylon.
Nylon is made by linear polymerization process of the two chemicals, hexamethylenediamine and adipic acid.
The steps involved are as follows:
(i) After polymerization, the polymer is extruded in a ribbon form and chipped into small flakes or pellets.
(ii) The polymer is melted and extruded through spinnerets into cool air.
(iii) The nylon filaments that are formed are then stretched to give strength and fineness.
(iv) The nylon filaments can then be woven into fabric.
LAUNDERING OF Fabrics.
Laundry processes are the steps to be followed when laundering personal or family clothes. They include the following:
1. Sorting: This is grouping the materials according to
(i) colour
(ii) types e.g. cotton, wool, polyester, etc.(iii) degree of dirt, and highly soiled fabrics.(iv) colour-fast and non-colour fast fabrics.
2. Mending: This is sewing or stitching split seams or tears and fastening loose buttons and hooks before washing.
3. Stain removal: Removal all stains accordingly before washing.
4. Soak or steeping: This is leaving the materials in water for some time to loosen surface dirt.
5. Washing: Washing is removing dirt from clothes with the aid of water and soap using any of the following methods:
(i) Washing by rubbing
(ii) Washing by kneading and squeezing
(iii) Washing by squeezing alone
(v) Using a washing machine if available.
6. Boiling: Boiling is used when necessary. It helps to whiten and disinfect clothes. Cotton and linen materials could be boiled e.g. babies’ napkins, handkerchiefs, white bed sheets, etc.
7. Rinsing: Rinsing is the process by which dirty lather is washed off the clothes.
8. Blueing and stiffening: Blue or stiffening agent could be added to the rinsed clothes if desired.
9. Drying: Drying is the complete removal of water from rinsed clothes. It could be by:
(i) exposure to sunshine
(ii) exposure under a shady but breezy place.
(iii) using an electric dryer.
10. Ironing: Ironing is pressing dried clothes with a hot iron in order to regain their original appearance.
For best results, clothes should be ironed while slightly damp or if they are very dry.
11. Airing:
Airing is hanging out ironed clothes in the open for a short time before storage. it helps to dry out the steam left in between the threads of the clothes after ironing.
12. Folding and storage: Aired clothes could be:(i) folded and stored in a box or drawers(ii) by hanging in a wardrobe.
Laundry Agents and Equipment.
Laundry agents are substances with cleansing properties for washing clothes.1. Water: This is a very important cleaning agent in laundry
Uses of Water for Laundry
(i) Water is used for soaking clothes and household articles before washing.
(ii) It cleanses articles with non-greasy dirt to a certain extent. For instance, sugar dissolves in water.
(iii) Hot water will melt and soften grease.
(iv) It is used for rinsing washed articles.
(v) It is used to dampen articles before ironing.
2. Detergents: A detergent is any substance that cleanses or aids the removal of dirt. Soaps and synthetic/soapless detergents are all detergents. soap is made by the reaction between fats/oil of animal/vegetable origin, and alkalis.
Synthetic detergents are made from mineral oil or petroleum products.
Uses of Detergents for Laundry
(i) Detergents are used to lower the surface tension of water.
(ii) Enable the water to wet the dirty articles/fabrics.
(iii) Break up grease-held dirt in the fabric into tiny particles.
(iv) Remove dirt from the fabric.
3. Bleaches:Uses of Bleaches for Laundry
(i) Make white cotton and linen fabrics whiter.
(ii) Remove certain stains.
(iii) Kill disease carrying germs in fabrics.
4. Stiffening agents: These include different types of laundry starch, as, hot water starch, cool water starch, spray or aerosol starches, gum Arabic, glue.
Uses of Stiffening Agents for Laundry
(i) To stiffen cotton and linen fabrics.
(ii) To give the fabrics a smooth surface.
(iii) To give the fabrics a fresh look.
(iv) To make fabrics keep clean for longer period.
Note: A starched article keeps clean longer than unstarched articles.
This is because dirt cannot adhere easily to the smooth surface.
5. Stain removers: A stain is a spot or a mark made on a fabric which gives a colour that is different from the rest of the surface of the fabric.
There are different types of stains e.g. vegetable, animal and grease stains.
Each type of stain requires a specific remover, as follows:
6. Laundry blue: This is used during the last rinse to improve the appearance of faded white material or materials with a blue background.
Laundry Equipment Laundry equipment are classified into groups:
1. Equipment for washing: These include:
(i) Galvanized or plastic buckets and basins.(ii) Laundry sinks or tubes.
(iii) Washing machines.
(iv) Laundry brushes
2. Equipment for boiling:
(i) Stainless steel pots.
(ii) Tongs for turning clothes while boiling.
3. Equipment for drying:
(i) Wooden or plastic pegs.
(ii) Clothes lines.
(iii) Hangers both for indoors and outdoors.
4. Equipment for finishing:
(i) Pressing irons e.g. box and flat, electric and steam irons.
(ii) Ironing boards.
(iii) Ironing pads.
Evaluation:
1. Give five factors to consider when laundering clothes
2. (a). Define the term laundering.
(b) List four laundry agents and their uses. (c) State three laundry agents and uses.
Presentation
Step 1
The subject teacher introduces the new topic
Step 2.
He introduces the new topic
Step 3:
The class teacher allows the pupils to give their own examples and he corrects them when the needs arise
Evaluation
1. Give five factors to consider when laundering clothes
2. (a). Define the term laundering.
(b) List four laundry agents and their uses. (c) State three laundry agents and uses.
3. Mention two uses of stiffening agents in laundry.
4. Mention two uses of Detergents for Laundry
5. Mention two uses of Water for Laundry
Conclusion:
The subject goes round to mark the pupil’s notes. He does the necessary corrections
