Class 8 Synthetic Fibres
Synthetic Fibres & Plastics
State whether ‘True’ (T) or ‘False’ (F) :
- Plastic is a natural polymer. F
- Nylon absorbs water and dries easily. F
- Silk is obtained from the silkworm. T
- Plastics are biodegradable. F
- Nylon is used to make parachutes. T
- We use nylon for making unbreakable dinner wares. T
Match the following :
- Silk (a) Rayon
- Wood pulp (b) Polyester
- Nylon (c) Thermosetting plastic
- Terylene (d) Nylon
- Melamine (e) Protein
- Rope (f) Toothbrush
- 1. a, 2- e , 3- f , 4- b , 5 – c , 6 – d
Give one word for the following:
- Fabrics that do not wrinkle easily.
2. Used to make non-stick cookware.
- Name two thermoplastic items.
Medical equipment and plastic chairs.
- Name two thermosetting plastic items.
Electrical insulator and tableware.
- Name one natural fibre.
6. Which synthetic fibre is called synthetic silk?
7.Which raw material is used to make nylon?
It is prepared from coal, water and air.
Short Answer Questions:
- Why should we not use plastics?
Once the plastic is used, it finds its way into our waterways and rivers. These plastic bags harm marine animals. When fish consumers this plastic, its body gets poisonous and when we consume this toxic fish, it affects us.
- State the characteristics of synthetic fibres.
Resistant to moths and fungi
Wrinkle resistant, dry up quickly
Easy to wash and care
Pick different dyes readily
- Write the properties of nylon.
Properties of the Nylon
It is strong and elastic.
It is easy to launder.
It dries quickly.
It retains its shape.
It is lustrous.
It is responsive to heat setting.
It is highly inflammable.
- What is plastics? Name any five commonly used articles made of plastics.
Plastics are a subspecies of a class of materials known as polymers. These are composed of large molecules, formed by joining many, often thousands, of smaller molecules (monomers) together. Plastics are made from low molecular weight monomer which is mostly derived from petroleum, that is joined together by a process called polymerization.
They are used on millions of items, including cars, bullet-proof vests, toys, hospital
equipment and food containers.
- How do carelessly thrown plastic bags (polyethene) affect : (a) Dirty water
drains and sewers? (b) Animals (such as cows)?
The poly bags carelessly threw here and there are responsible for clogging the drains, too.
(b) Garbage dump where animals, especially cows, are eating garbage. In the process of eating the food waste, they swallow materials like polyethene bags and wrappers of food. The plastic material chokes the respiratory system of these animals, or forms a lining in their stomachs and can be the cause of their death.