POLYMERS

Thermoplastics

can be repeatedly softened by heating and hardened by cooling

• acrylic

• PET

• PVC

• PP

• ABS

Acrylic

• tough

• lightweight

• used for lenses, glasses, shower trays

PET

• tough

• flexible

• lightweight

• used for packaging, clothes

PVC

• tough

• rigid

• flexible

• used for pipes, electrical insulation

PP

• tough

• flexible

• resistant to chemicals 

• used for food packaging, medical equipment

ABS

• tough

• hard

• impact strength

• used for saftey helments, suitcases

Thermosetting

can only be heated and shaped once

• Epoxy resin

• UF

• Polyester resin

Epoxy resin

• tough

• hard

• good chemical resistance 

• encapsulating electrical components 

UF

• high tensile strength 

• hard

• resistant to deformation 

• used for electrical casings, sockets, switches 

Polyester resin

• resistant to water, heat, and chemicals 

• used for bath tubs, boat hulls 

Vaccum Forming Method 

• materials used: HIPS, Polyester, ABS, Acrylic

• used for plastic yogurt, pots, bath tubs

1. the mould is created from mdf/plywood

2. The mould is placed into vacuum former

3. plastic sheet placed into vacuum former and heated until pliable 

4. mould is raised up into the sheet and air is removed to seal it

5. plastic takes shape of mould and allowed to cool

6. remove mould once cooled

Injection Moulding Method 

• Materials - ABS, Acrylic, PVC

1. Beads, pellets, granites are placed into hopper

2. they are fed through and archimedes screw drag granules through melting it

3. once pass through heater and become liquid, hydraulic piston forces it into mould

4. plastic cools and takes shape of mould

5. removes mould using ejector pins

Blow Moulding method

• Materials - HDPE, PP, LDPE, PET

• water bottles, toys, bins

1. plastic is heated and extruded to create a piston 

2. piston is placed in the mould, which closes on it and pinches the end of plastic 

3. heated compressed air is blown into piston

4. plastic fills in the mould with hollow interior

5. plastic is cooled using water

6. once cooled, remove mould and trim excess plastic

Rotational moulding method

• Materials - HDPE, PP

1. plastic is weighed depending on desired thickness and put into mould

2. mould is placed on rig in huge oven and heated

3. as its heated it is rotated on 2 axes to allow polymer coat evenly

4. once desired thickness reached mould is cooled

5. remove from mould

Line Bending method 

• materials - Acrylic 

1. mark out line that requires bending 

2. preheat the strip heater to right temperature 

3. add the plastics in heater on marked out line 

4. once heated bend plastic to desired angle