Fabric to Fabric Class 7 Science Notes - Chapter 3
Fibre to Fabric Class 7 Science Notes - Chapter 3
Overview of the chapter
In Class VI, we learned about some plant-based fibres. In this chapter, we will look at some animal-derived fibres. Animals are used to produce wool and silk fibres. Wool is derived from the fleece (hair) of sheep or yak, while silk fibres are derived from silk moth cocoons.
Fibres are very thin, thread-like strands used to make fabrics (or cloths). Cotton, wool, silk, flax, jute, nylon, polyester, and polyacrylic are some examples of fibres. The fibres are spun into yarn (a long continuous thread) that can then be woven into fabric on a loom (or cloth). Yam is a long and twisted thread. The spinning process creates yarn from fibres
Natural fibre and man-made fibre are the two types of fibres (nylon, rayon). Some of our clothing is made with yarn derived from animal fibre. These are the different types of natural fibres that can be found in nature. Natural fibres are fibres derived from natural sources such as plants and animals.
Fibres from Plants
Plant fibre is primarily made up of cellulose and cellulose fibres. These are most commonly used in the production of paper and cloth.
- When cellulose is properly prepared, it produces long, lustrous fibres.
- Plant fibres are derived from plants such as cotton, jute, flax, and hemp.
- Cotton is widely used for its softness, absorbency, and versatility.
- Flax is a strong and durable fibre used in linens and clothing, rope and twine.
- Hemp is a versatile plant fibre that can be used for a variety of purposes, including the production of clothing, paper, and building materials. It is also used as a source of food and medicine.
- Jute is a strong, coarse fibre that is often used in the production of burlap, sacks, and twine. It is grown in warm, humid climates and is one of the most affordable plant fibres.
Basics of Fabric
Fibres
- Fibre is the name for the thread's finer end.
- Fibre is a structure that resembles a thread and is spun into ropes, textiles, and strings.
- Fibres from either natural or synthetic sources are used to create fabrics. Examples include polyester, nylon, and rayon.
Fibre to Yarn to Fabric
Fabric consists of thin strands called yarn, which in turn consists of thinner strands called fibres.
Wool
Wool comes from animals like sheep, goat, yak, camel, llama and alpaca, which bear a thick coat of hair which traps air and keeps them warm in winter.
Animals that Yield Wool
Sheep wool is the most prevalent type of wool on the market. Different regions of our country have different sheep breeds. Wool does not only come from sheep's wool; there are other places where it can be found.
some Indian Breed of Sheep which provide wool
| Name of Breed Of sheep | Quality of wool | Name of the state where Found |
|---|---|---|
| Lohi | Good quality wool | rajasthan, Punjab |
| Rampur bushier | brown fleece | uttar pradesh, himchal pradesh |
| Nali | carpet wool | rajasthan,haryana, Punjab |
| bakharwal | For woollen Shawls | jammu and kashmir |
| marwari | coarse Wool | Gujarat |
| patanwadi | for hosiery | gujarat |
Other places to find wool are
- In Tibet and Ladakh, yak wool is widely used.
- In hilly areas like Jammu and Kashmir, angora goats produce wool that is used for clothing.
- Soft Kashmiri goat underfur is woven into luxurious shawls known as pashmina shawls.
- Camels' body hair (fur) is used to make wool.
- South American llamas and alpacas produce wool as well.
From Fibres to Wool
Sheep are the main source of the wool. Sheep are raised and bred for their wool, which is then processed from their hair. We'll start off by talking about raising and breeding sheep.
Rearing and Breeding of Sheep
Rearing: It is the process of breeding, feeding, and caring for sheep. These animals are kept because they make one or more useful products for humans.
Breeding: Sheep are bred in order to produce breeds that produce copious amounts of high-quality wool. These sheep breeds are referred to as sheep of good breeds because they have a thick coat of hair on their bodies. The quantity and quality of wool produced increase as a result
Processing fibres into wool
Step 1: Shearing is the process of removing the sheep's fleece and thin layer of skin from the body. It is done in hot weather of summer so that the sheep can survive without their protective coat of hair. The fleece provides woollen fibres, which are processed to obtain woollen yarn.
Step 2: The fleece of sheep is thoroughly cleaned by washing with soap and water in tanks. This process is called scouring and is done by machines now-a-days. The scoured fleece is then dried.
Step 3: Sorting is the process of separating the fleece of a sheep into sections according to the quality of woollen fibres. After scouring, the hairy skin is sent to a factory where hair of different textures is separated or sorted. Every section of wool obtained after sorting contains the same quality wool, which is then mixed together.
Step 4: Burrs, which are tiny fluffy fibers, are removed from the hair (burrs are soft, fluffy fibres in wool).
(The fibers are then dried and scoured once more. The resulting wool is ready to be drawn into fibers.
Step 5: Sheep (or goat) natural fleece or hair is white, brown, or black in color. Sorted white woollen fiber can be dyed in a variety of colors.
Step 6: Straighten, comb, and roll the fibers into yarn. The long woollen fibers are spun (or twisted) into a thick yarn called wool, which is used to knit sweaters and other garments.
Woollen clothing is made by spinning short woollen fibers into fine yarn and weaving it on a loom (like shawls, etc).
Occupational hazards of fibre production
The wool industry is an important source of livelihood for many people in the country. Sorters are responsible for sorting the fleece of sheep into fibres of different qualities, but their job is risky due to the risk of getting infected by anthrax, which can cause a deadly blood disease called sorter's disease. Sorter's disease is an occupational hazard.
Silk
Silk is a natural fiber derived from an insect (called silk moth). As a result, silk fibers are also animal fibers. The silk fibers are spun by silkworms. Silk fiber is made of a protein. Silk is the most durable natural fiber.
Sericulture
Sericulture is a term for "silk farming." Sericulture is the practice of raising silkworms to produce silk. In India, sericulture is a very old profession. India is a major commercial producer of silk. The fascinating life history of the silk moth must be understood before we can talk about the production of silk.
Silk from Animals
Silk is a naturally occurring protein fiber that can be used in textiles and is obtained from silkworms.
Different kinds of silkworms produce the various types of silk.
It can be distinguished based on texture and lustre. Kosa, Tassar, Mooga, etc. are a few examples. Different varieties of silk moths produce them. The mulberry silk moth is one of the popular varieties.
Silk Moth Life Cycle Silkworm Formation
Female silk moths lay their eggs on mulberry leaves. Within a week, the eggs hatch into very small larvae. Caterpillars or silkworms are the larvae of the silk moth. Silkworms grow in size as they feed on the leaves of the mulberry tree.
Fabrication of Silk from Cocoons
Cocoons are collected and either left in the sun or boiled to separate the silk fibers.
After the silk has been reeled, the process of unwinding silk from a cocoon begins.
After that, silk fibers are spun into threads.
The silk threads are woven into the desired clothing
Fibres from Nature
Natural fibers are naturally occurring fibers derived by humans from plants or animals.
Animal fibers: These are fibers obtained from animals. Wool, silk, and so on.
Plant fibers: These are fibers derived from plants. These fibers are extracted from plants and used to make fabrics.
Artificial Fibers
Synthetic or man-made fibers are fibers that are created by humans using chemicals.
These outlast natural fibers in terms of durability.
For instance: acrylic, nylon, and polyester.
KEY TERMINOLGY
Cocoon: a cocoon is a protective covering made of silk or other fibers, created by some species of moths and caterpillars to enclose and protect their pupa.
Fleece: Fleece is a type of fabric that is made from synthetic fibers, such as polyester or recycled plastic. It is soft, warm, and lightweight, and is often used to make clothing and accessories for outdoor activities, such as jackets, vests, hats, and blankets.
Reeling: Reeling is a process that involves winding a flexible material, such as fiber, yarn, wire, or film, onto a spool or reel. This process is used in a variety of industries, including textiles, fishing, cable and wire manufacturing, and film and video production.
Silk moth: The silk moth is best known for the silk cocoons that it spins around itself as it transforms from a caterpillar to a pupa. These cocoons are harvested for their silk fibers, which are then woven into fabric.
Silkworm: A silk worm is the larval stage of the silk moth (Bombyx mori), a species of domesticated moth that is commonly used for commercial silk production. The term "silk worm" is often used to refer to the caterpillar of the silk moth, which is the stage of its life cycle during which it spins a cocoon made of silk fibers.
Sorting: Sorting of fibers refers to the process of arranging fibers into specific orders based on their properties such as length, thickness, color, texture, and strength. The sorting process is essential for many industries that use fibers, including textiles, paper making, and composites manufacturing.
Scouring: Scouring is a process that involves cleaning fibers or textiles to remove impurities and natural substances, such as dirt, grease, oil, wax, and proteins, that can affect the quality and strength of the final product.
Sericulture: Sericulture is the process of raising silk worms for the production of silk. It involves the cultivation of mulberry leaves, which are the main food source for silk worms, as well as the breeding and care of the silk worms, the spinning of their cocoons, and the harvesting of the silk fibers.
Shearing: Shearing is a process that involves cutting a material, typically a soft or flexible material, into a desired shape or size. There are different types of shearing processes, including mechanical shearing and thermal shearing, which use different methods to cut the material.
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