Thermoforming and thermosetting polymers

Question 1

What are thermoforming polymers?

Answer 1

These are materials that can be heated and shaped repeatedly, and are able to be recycled.

Question 2

What are some types of thermoforming polymers and their properties?

Answer 2

• Acrylic - Hard, good plasticity, weather resistant, scratches - car headlights, baths
• Polypropene (PP) - lightweight, strong, good heat/chemical resistant - patio chairs, cling film
• Polyvinyl chloride (PVC)- Low cost, glossy/matte, flexible/rigid, chemical/weather resistant - Window/door frames gutters
• High density polythene (HDPE) - lightweight, chemical resistant, plasticity - buckets, pipes
• Polystyrene (PS) - cheap sheet, coloured/transparent - used in schools for vacuum forming.

Question 3

What are thermosetting polymers?

Answer 3

These are materials that are formed once and cannot be recycled.

Question 4

What are some types of thermoforming polymers and their properties?

Answer 4

• Melamine formaldehyde - resistance to heat, moisture, scratching and staining. - kitchen worktops
• Epoxy resin - strong adhesive, chemical and heat resistance, thermal insulation
• Urea formaldehyde - hard, stiff, electrical insulation - plugs, switches, electrics
• Polyester resin - forms reaction of acids and alcohols - sheet moulding compound

Question 5

What are the sources of polymers?

Answer 5

Polymers can be made from natural and synthetic resources.
- Synthetic polymers are made from crude oil by scientists and engineers.
- Natural polymers are made using a variety of materials like silk, wool, cellulose and proteins.

Question 6

What are the differences between thermoforming and thermosetting
polymers?

Answer 6

The main difference is that a thermosetting polymer will strengthen when heated, and cannot be remoulded or heated after the initial forming.
A thermoforming polymer can be reheated, remoulded and cooled as needed without causing a chemical change.

Question 7

How may polymers be finished?

Answer 7

• Most polymers already have a smooth finish.
• If a polymer has been cut from its original stock form, for example a piece of acrylic cut from a sheet, the edges that have been cut will be rough, and they will need to be finished.
• Other finishes can be applied to polymers. These include paint spraying, rubberising sprays and heat transfer printing.