Introduction to fibres - class-XI

yes, Yarn is made from fibres by spinning.

Natural fibres are fibres extracted from plants and animals. 

Cotton is a natural fiber it has the tendency to absorb the sweat. Also, its a breathing fabric and so allows air to pass through keeping your body cool.  cotton is the best fabric to use in summer.

Coir is extracted from the tissues surrounding the seed of the coconut palm. 

Cotton is the fibre that bums completely, leaving no residue.

In summer, it is advised to wear clothes made of cotton. We sweat a lot in summers. Cotton is a good absorber of water. Thus, it absorbs sweat from our body and exposes the sweat to the atmosphere, making its evaporation faster.

Hill stations are crowded and have waste disposal problem. Thus, plastic use should be minimum. Some hill stations like Nainital, have banned use of polyethene bags.

The fruit part of cotton plant yields cotton balls.

The outer covering of coconut is called coir.

Fibers  are a class of hair-like materials that are continuous "'filaments"' or are in discrete elongated pieces, similar to pieces of thread. They can be used as a component of composite materials. 

Animal fibers are generally made up of proteins. 

Natural fibres are obtained from plants and animals.

Cotton is obtained from cotton plant and wool is obtained from sheep.

Animal fibers are natural fibers that consist largely of particular proteins. These proteins include collagen, keratin and fibroin.

Fibres which are man-made are called synthetic fibres and which occurs naturally are called natural fibres. Rayon (synthetic fibre), when mixed with cotton (natural fibre), is used to making curtains, bedsheets etc. of clothes, ropes, seat-belts, curtains, sleeping bags, parachutes, tents etc.

Use of charkha was popularized by Mahatma Gandhi as part of the Independence movement. He encouraged people to wear clothes made of homespun yarn and disapprove of imported cloth made in Britain. Charkha is a handmade device used to spun yarn.

The suitable climate for growing jute is a warm and wet climate, which is offered by the monsoon climate during the fall season, immediately followed by summer. Temperatures ranging from 25-30 °C and relative humidity of 70%–90% are favorable for successful cultivation. Jute requires 160-200 cm of rainfall weekly with extra needed during the sowing period. River basins or alluvial or loamy soils are best for jute cultivation. Jute cultivation in red soils may require a high dose of manure.

Fibres can be classified as natural fibres and synthetic fibres.
Natural fibres are obtained from plants and animals. The examples of such fibres include cotton, jute, silk and wool.
Synthetic fibres are made from chemical substances, which are not obtained from plant or animal sources. Examples include polyester, nylon and acrylic.

A, B and C are natural fibres. 

The example of Natural polymers are ;- wool, silk, amber, cellulose etc.

Nylon is a synthetic fibre.

Rayon or artificial silk, nylon and acrylic represents fibre. Polyester and cotton are another example of fibre.

 All of the following represent(s) the characteristics of synthetic fibres.
They dry up quickly.
They are durable
They are less expensive and readily available.
They are easy to maintain

Burrs are the small filthy fibers. This has a pattern of knots. 

The female silk moth lays 200 eggs at a time, these eggs are stored on strips of cloth. The stored eggs are then kept under hygienic conditions, suitable temperature and humidity.

Table is made up of wood or wood pulp but cloth, rope and carpet are made up of various types of fibres and yarns which form these materials.

Endoscopes use bundles of optical fibres to transmit light and images from inside the body, relying on the principle of total internal reflection.

Synthetic fibres are also called as artificial or human made fibres since they are made by human in factories.

Spandex, Lycra or elastane is a synthetic fiber known for its exceptional elasticity. It is stronger and more durable than natural rubber. Because of its elasticity and strength (stretching up to five times its length), spandex has been incorporated into a wide range of garments, especially in skin-tight garments. A benefit of spandex is its significant strength and elasticity and its ability to return to the original shape after stretching and faster drying than ordinary fabrics.

Cellulose is made up of glucose units by glycosidic bonds.

Cotton bolls.

$Fibres$ are the thread forming solids which possess high strength and high modulus. This characteristic is attributed to the strong intermolecular forces like hydrogen bonding.

Weaving is a method of textile production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth. Cloth is made by crossing two sets of threads over and under each other. The two sets of threads are called warp and weft.