The very thin thread-like strand from which cloth is made is called fibre.

* It is also called tantu or resha in hindi.

Yarn/thread: -       The long continuous length of interlocked fibres is called yarn or thread.

* It is used to production of textiles, sewing, knitting, weaving, embroidery or rope making.

Fabric: - The weaving or knitting of yarn/thread is called fabric or cloth.

Types of Fibre

Natural fibres: - The fibres that are obtained from plants and animals are called Naturalfibres.

Ex- Jute- From stem of jute plant.

Wool- From fleece of sheep and goat.

Cotton- From bolls of cotton flower.

Silk - From cocoons of silkworm.

Linen -From stalk of a plant (flax).

Types of Natural fibre:

Plant Fibre: - Fibre obtained from plants is called plant fibre/vegetable fibres.

Ex– cotton, jute, flex, etc.

Animal Fibre: - Fibre obtained from animals is called animal fibre.

Ex- wool and silk

Note: -           

* Wool burns with a bad smell because wool is rich in protein.

* Cottondoesn’t burn with a bad smell because cotton is rich in carbohydrate.

Synthetic Fibres:-Fibres that are synthesized in laboratory are called synthetic fibres.

Ex- Nylon, polyester, terry-cotton, acrylic, etc

Types of Fibres

Petrochemicals: - Those raw materials which obtained from petroleum and used to make synthetic fibres are called petrochemicals.

Polymer:- Those synthetic fibre which is made of multiple units of a chemical called polymer. All synthetic fibres are polymers.

* The individual unit in a polymer is called the monomer. Thus, a polymer is made up of many monomers.

* Naturally occurring polymers are proteins, starches, cellulose and latex.

* Cotton is made up of a polymer called cellulose. Cellulose and starch is made upof a large number of glucose units. Plastics are synthetic polymers.

* Polymers are form by chemical reaction in which a large number of monomermolecule arejoined sequentially, forming a chain.

Types of Synthetic Fibre

Rayon: -Rayon is first semi-synthetic fibre, prepared by chemical treatment of wood pulp (cellulose).

Q 1.Why rayon is different from synthetic fibre?

Sol:-Rayon is different from synthetic fibres because it is semi-synthetic. Raw material used for preparation of rayon is cellulose which is derived from plant cell wall.

* Rayon is similar to silk but is cheaper than silk. Hence, rayon is also called ‘poor man’s silk’.

* Rayon can absorb sweat. So, it is preferred over other synthetic fabrics in summer season.

* Rayon can be dyed in various colours.

* Rayon is usually mixed with cotton to make bedsheet and dress materials.

Nylon: - Nylon was made in 1931. The term ‘nylon’ has been derived from letters of ‘New York’ and ‘London’. Nylon is made from coal, water and air. Hence, nylon is called the first truly synthetic fibre. No ingredient from plant or animal source was used in making nylon.

* Nylon is strong, light and elastic.

* It is lustrous and easy to wash.

* Nylon is used in many articles; like socks,sarees, shirts, bags, toothbrush, rope, sneakers, parachute, umbrellas, etc.

* For the same thickness, a nylon thread is stronger than a steel wire.

Polyester: - Polyester is made of repeating units of a chemical called ‘ester’.

* All fruits and flowers have specific smell because of specific ester present in them.

* Terylene is a popular polyester which is used in dress materials.

* PET (Poly Ethylene Terephthalate) is another example of polyester. It is used for making bottles, utensils, films (magnetic recording tapes in cassettes), wires and many other items.

* Polyester fabrics do not wrinkle easily and are easy to wash.

Acrylic: -  Acrylic resembled wool and hence is also called synthetic wool.

* It is cheaper and more durable than wool, and is easier to wash and maintain.

* It is used for making sweaters, shawls, suits, and trousers etc.

Characteristics of Synthetic Fibres:

* They are less expensive.

* They are readily available.

* They can be easily washed.

* They are easy to maintain.

* They are durable.

Disadvantage of synthetic fibres

* They can absorb very little moisture.

* They have low melting points so melt easily.

* They are not biodegradable and hence causes a lot of pollution.

Q 2. Synthetic fibres are more popular than natural fibres. Why?

Sol:-Because of superior qualities, more durability and affordable cost.so,synthetic fibres are more popular than natural fibres.

Plastics:- Plastics is a polymeric substance that can be moulded when soft and then hardened on cooling to produce a durable article. It is made soft by applying heat and pressure before moulding.

Types of Plastic (on the basis of their reaction to heat)

Thermoplastic: -Those plastics which can be melted by heating andmoulded (dhala Jana) into desired shapes and sizes repeatedly are called thermoplastic.Ex: -Polythene, PVC, nylon, Terylene, etc.

* Thermoplastic is used for making combs, toys buckets, mugs, plastic films, polybags, grocery bags, bottles. Etc

Thermosetting Plastic: -Those plastics which cannot be melted by heating and cannot

bemoulded (dhala Jana) into new shapes and sizes are called thermosetting

plastics. Ex:-Bakelite, melamine, polyuria, duroplast.

* Bakelite is used for making electrical switches and switchboards, handles of utensils. Melamine is resistant to fire and is hence used for making utensils and floor tiles.

On the basis of arrangement of monomers, plastics can be of two types:-

1. Plastics with linear arrangement of monomers:-Those plastics in which monomers are arranged in a straight line chain are called Plastics with linear arrangement of monomers. These plastics are generally thermoplastics.

2. Plastics with cross linked arrangement of monomers:-Those plastics in which monomers are arranged in crossed linked are called Plastics with cross linked arrangement of monomers. These plastics are generally thermosetting plastics.

Properties of plastics

1. Plastics can be recycled, reused, rolled into sheets or made into wire.

2. Plastics are non-reactive with moisture and air and insoluble in water so, they are used to store various kind of chemicals.

3. Plastics is light in weight, strong and durable and moulded into different shapes and sizes.

4. Plastics are poor conductors of heat and electricity, that is why, electrical wire coverings, handles of screw drivers and frying pans are made of plastics.

5. They may be transparent, translucent, and opaque.

6. They are low in cost.

Biodegradable: - A material which can be decomposed by microbes is called a biodegradable material. 

Ex- Jute, cotton, paper, leftover food, etc

Non-biodegradable:- A material which cannot be decomposed by microbes is called a non- biodegradable material.

Ex- Plastic, iron, copper, etc.

* Plastic has become very popular due to many of its inherent benefits. But the non-biodegradable nature of plastic poses a big problem. Plastic waste is getting accumulated all around us, in the street, in drains, on garbage dumping sites, etc. So, it is not environment friendly. It causes environmental pollution (air, water, and land)

Nuisance (problem) of plastic bags:

* Plastic bag keeps on accumulating in the environment.

* It chokes drains.

* A stray animal can die if it accidentally swallows plastic bag.
How to tackle (निपटना/रोकना) the problem of plastic waste?

* Follow the principles of 4R’s, i.e. Reduce, Reuse, Recycle and Recover.

* Use recyclable plastic or use shopping bags of cloth or jute.

* Do not throw plastic bags on roads or in drains.

* Reuse plastic containers for keeping household items.