1.3 Enhancement of Materials

Question 1

Lubricants

Answer 1

Wax and calcium stearate, reduces the viscosity of the molten polymer making it less ‘sticky’ allowing more intricate shapes to be formed and allows the moulding temperature to be lowered, saving energy.

Question 2

Thermal Antioxidants

Answer 2

Help to prevent the polymer oxidising or discolouring due to excessive heat during processing

Question 3

Pigments

Answer 3

Tiny particles that are mixed into the polymer in the molten stage to give colour to the final processed product

Question 4

Antistatics

Answer 4

Insulate products such as electric wire covers, plugs and sockets due to their poor electrical conductivity. Insulating properties can lead to a build up of static electrical charge which attracts dirt and dust. The antistatics improve the surface conductivity by attracting moisture from the room surroundings therefore reducing the static charge.

Question 5

Flame Retardants

Answer 5

Reduce the likelihood of combustion or spread of fire. Metals or chlorine added to polymers such as polyester.

Question 6

Plasticisers

Answer 6

Added to plastics such as PVC to become less hard and brittle at normal temperature. Added to LDPE in manufacture of food allowing wrap to be stretch over food product. Help in processing because they allow polymers to be easily formed.

Question 7

Fillers

Answer 7

Provide bulk to the product meaning that less polymer is required and to improve the polymer properties. Commonly used fillers are sawdust and wood flour and mineral fillers such as chalk and clay. Sawdust and flour provide bulk reducing the amount of polymer required. Mineral fillers can help increase the thermal conductivity of a polymer giving shorts mould cycle times.

Question 8

Antioxidants

Answer 8

Help to reduce the environmental deterioration of the polymer from exposure to oxygen.

Question 9

UV Light Stabilisers

Answer 9

Prevent polymer chains being broken down by sunlight. UV exposure causes polymers to lose colour and become brittle.

Question 10

Biodegradable plasticisers

Answer 10

Make polymers more flexible, softer and easier to break down which means faster degradation time.

Question 11

Bio-batch additives

Answer 11

Oxy-degradable, photodegradable and hydro-degradable additives added to polymers reduce degradation time from hundreds of years to few months or years. Oxy-degradable additives used in high volume single use items such as carriers bags.

Question 12

Enahncemenet using perservatives

Answer 12

Important for outdoor timber, protecting wood from fungal and insect attack. Often, a copper based preservative is used because is it a naturally occurring mineral with excellent fungicidal properties. Preservatives with pigments used to enhance aesthetics. Preservatives with fire retardant properties used to pressure treat wood for roof systems and cladding. Wood can be impregnated with polyaccharised effective cure with the wood structure similar to cellulose in timber. Combined with pigments. inexpensive softwoods can be made to look like expensive hardwoods. Which is good for the environment as softwoods grow much faster than hardwoods.