Polymers (incomplete)

Question 1

thermoforming/ thermo polymers

Answer 1

plastics which can be heated and reformed into a new shape with linear unlinked polymer chains

Question 2

thermosetting polymer

Answer 2

polymers formed in a chemical reaction with polymer chains linked together, these polymers cannot be heated and reformed

Question 3

elastomer

Answer 3

polymers that can be deformed under a force and return to there original shape when the force is removed

Question 4

granules (stock form)

Answer 4

small particles of a polymer

Question 5

sheet (stock form)

Answer 5

large flat sections of polymer with varying thickness

Question 6

film (stock form)

Answer 6

very thin polymer sheet

Question 7

Rods / extrusions (stock form)

Answer 7

specifically designed polymer bar to match a purpose

Question 8

bar (stock form)

Answer 8

solid long pieces of polymer with a round or square cross section

Question 9

tube (stock form)

Answer 9

hollow bar with a range of cross sections

Question 10

Foam (stock form)

Answer 10

solid polymer with gas pockets to reduce density and weight (e.g. polystyrene)

Question 11

Powder (stock form)

Answer 11

very fine granulated polymer

Question 12

natural polymer

Answer 12

polymers that already exist in nature (e.g. cellulose)

Question 13

Lubricants

Answer 13

wax or calcium stearate makes the polymer less viscous which allow it to more easily fill complex and highly detained moulds.
it also reduces moulding temperature as the idea viscosity occur at a lower temperature

Question 14

thermal antioxidants

Answer 14

additives that prevent a polymer from discolouring or oxidising under the excess heat when melted

Question 15

Pigments

Answer 15

tiny coloured particles which are added to molten polymer allowing control of the materials aesthetics

Question 16

Antistatics

Answer 16

additives which remove static charge which builds up on the surface of the insulated polymer which could damage electronic components and attract dirt

Question 17

Flame retardants

Answer 17

reduce the combustibility of the polymer making it safer for high fire risk applications such as plug sockets

Question 18

Plasticisers

Answer 18

reduces the hardness and brittleness of polymers to allow them to be bent and formed more easily

Question 19

Fillers

Answer 19

cheap bulk products such as sawdust are put into molten plastic keeping the properties the same while reducing the volume of expensive polymer needed.
some additives such as clay or chalk increase thermal conductivity to decrease mould cycle times

Question 20

Biodegradable plasticisers

Answer 20

these make the product more flexible and softer to speed up its breakdown when disposed of

Question 21

Bio-batch additives

Answer 21

Oxy, hydro or photo degradable additives which speed up the break done of the polymer after use

Question 22

Antioxidants

Answer 22

additives which reduce the oxidation of the polymer in an outdoor environment which could weaken and discolour the plastic

Question 23

UV stabilisers

Answer 23

additives which protect the polymer from being broken down by UV light which will discolour and weaken certain plastics like PVC

Question 24

Vacuum forming

Answer 24

Stock - thermoplastic sheet up to 6mm
Products - lightweight trays, box inserts and liners, takeaway coffee cups and yoguurt pots
Features - mould easy to make but needs draft angels and air holes. Not good for oneoffs. Small-scale batch and mass production

Question 25

Thermoforming (process)

Answer 25

Stock - thermoplastic sheet around 6mm
Products - bath, food packaging, fruit punnets, cake boxes, sandwich boxes
Features - like vacuuming forming but using another mold one on top and bottom at the same time vacuuming is applied. Better detail because of this. Slow process used in industry.

Question 26

Calendering

Answer 26

Stock - thermoplastic pellets
Products - thin polymer sheets and film
Features - heated rollers squash and stretch polymer to make it thinner. Industrial possess done by specialist manufacturer. Continues production

Question 27

Line bending

Answer 27

sheet plastic is placed on top of a thin wire heating element which heats the plastic only along that line causing it to become flexible so it can be bent into shape

Question 28

Lamination (lay up)

Question 29

Injection moulding

Answer 29

thermoform pellets are fed down a hopper into an archimedian screw which pushes the forwards into a heating element
the plastic melts into a liquid
a piston pushes forward forcing the liquid plastic into the mould causing it to take its shape
the mould is cooled with a water jacket
the mould splits in two and ejector pins release the final product

Question 30

Blow moulding

Question 31

Rotation moulding

Question 32

Extrusion

Question 33

Compression moulding