Test: Synthetic Fibres & Plastics- 1 - UPSC MCQ

Yarn is twisted to form thread. Thread is a type of yarn intended for sewing by hand or machine. Yarn is a long continuous length of interlocked fibre.

Synthetic clothes catch fire very easily.Fabric can melt and stick to the body of the person wearing it.

Plastics are non biodegradable, resistant to weather and durable. Plastic can be recycled too. It is used to make chairs, rope, bucket and a number of other utensils.

Terylene blended with wool is known as terrywool.

Synthetic fibers are made from petroleum polymers and are often less expensive than their natural plant and animal counterparts. These synthetics first appeared on the scene with artificial silk in 1894, and other fibers were developed throughout the 20th century, such as Rayon, Nylon, Acrylic and Polyester.

So, dacron, acrylon and acrylic are petroleum products.

Melamine is a thermosetting plastic as it cannot be moulded by heating. Polyester, Nylon and PTFE are thermoplastic that can be change in shape by heating.

When plastic is burnt, they release toxic gases that includes, carbon dioxide, carbon monoxide, sulphur dioxide etc. They cause air pollution.

Rayon is called as artificial silk. It is obtained from wood pulp containing cellulose. Chemical treatment of wood pulp forms rayon fibre which can be dyed in a variety of colours.

Polyvinyl chloride (PVC) is a thermoplastic which can be remoulded by heating. It is used for making pipes and other materials which is flexible and durable.

Unbreakable kitchenware is made from melamine. Melamine is a thermosetting plastic is resistant to fire and can tolerate heat better than other plastics.

Protein, animal fibres are natural fibres that consist largely of particular proteins. Instances are silk, hair/ fur and feathers. The animal fibres used most commonly both in the manufacturing world  as well as by the hand spinners are wool from domestic sheep and silk.

PET is  polyethylene terephthalate, a plastic resin and a form of polyester. Polyethylene terephthalate is a polymer that is formed by combining two monomers: modified ethylene glycol and purified terephthalic acid. The first PET bottle was recycled in 1977.

• The saturated solid state refers to a condition where a solid can transition to a liquid when heat is applied.
• This occurs at a specific temperature known as the melting point, where the solid absorbs heat but remains at constant pressure.
• At this point, the solid and liquid phases coexist, allowing the solid to melt into a liquid without changing the pressure.

Raw materials for the synthetic fibres are derived from petroleum products using a number of processes. Therefore, these fibres are called as synthetic fibres.