More on Production of Materials

Question 1

There are Many types of fibes

Answer 1

Fibres are tiny hairs that are spun into yarns- the threads that are woven or knitted into fabrics
Fibres come in either short lengths (staple fibres) or longer lengths (filaments) . Longer lengths can then be cut up if needed.
Fibres fall into three categories- natural, regenerated and synthetic.

Question 2

Natural fibres are from natural sources

Answer 2

Wool is from sheep’s fleece:
The sheap is sheared, the best wool comes from the shoulders and sides
Cleaning and scouring (washing with harsh chemicals) removes grease and dried sweat
The fibres are then combed using wire rollers- this is called carding

Cotton is from the seeds of cotton plants:
Before harvesting, the plants are treated with chemicals that cause the leaves to drop off
Fibres are cleaned to remove dirt
Seeds are removed
Carding

Silk comes from the cocoon of silk worms
The cocoon protects the worm whilst it becomes a moth
The cocoon is one piece of silk fibre, a filament. It is stuck together with a hard gum called sericin.
The gum is softened by soaking in warm water. the filament is then unwound

Question 3

Regenerated Fibres are chemically treated natural materials

Answer 3

Regenerated materials are made from natural materials- usually cellulose fibres from wood pulp
Different fibres are made from different chemicals eg Viscose fibres are made from sodium hydroxide (NaOH)

Question 4

Synthetic fibres are made from polymers.

Answer 4

Synthetic fibres are man made. Made from crude oil. Examples include polyester, lycra and nylon

Crude oil is fractionally distilled and some of the products are made into polymers
The polymers are melted and forced through holes
They are then cooled to form long filaments

Question 5

Material production can impact the environment

Answer 5

The consequences of mineral extraction can have a negative effect on the environment. Habitat loss and climate change are often attributed to this.
Sometimes the raw material is the problem: harvesting wood for timber causes deforestation, this may have a negative effect on species that rely on the forest for habitat or food.

Drilling for oil is the first step in polymer production. It is drilled for on land and out at sea. It can release toxic chemicals into the water and the atmosphere. Waste and oil can also leak causing large scale environmental damage. Land has to be cleared to drill for oil.

Mining metals uses a lot of energy from fossil fuels. This causes air pollution and contributes to global warming. Habitats are destroyed and large areas of land can be affected by the chemicals used to extract the minerals.

Farming for natural fibres often uses artificial fertilisers and pesticides to increase the yield of the crops. These can pollute the rivers and harm wildlife. It also requires lots of land to be effective.