Selecting Plastics

Question 1

What are the two catagories of plastics ?

Answer 1

Thermosetting- heat cannot change the polymers form once set

Thermoforming- heat and shaped then reheated and shapes

Question 2

Why is acrylic often used it school ?

Answer 2

Can be heated and bent using a line bender
It’s a thermoforming polymer

Question 3

What are the four polymers used in schools V

Answer 3

Acrylic
Polypropylene
High impact polystyrene
Polylatic acid ( PLA)- 3D printing filament

Question 4

Why is there a drive to reduce the use of plastics ?

Answer 4

They don’t biodegrade quickly and can pollute oceans

Question 5

Why is 3D printing increasingly more popular ?

Answer 5

• complex, intricate and curved shapes can be produced quickly and cheaply
• most common filament is PLA

Question 6

What are some PLA filaments combined with and why ?

Answer 6

• carbon fibre, wood fibres and even metal
• greater range of material choice

Question 7

What are some factors for considering design and production ?

Answer 7

Cost
Environment
Employees
Manufacturing process
Material availability

Question 8

If a roll of carbon fibre filament costs £ 45 for 750g and 25 parts for a prototype need to be printed what will the cost of the print be ?

Answer 8

Find cost per gram of filament
45 divided by 750= 0.06

Cost per part

0.06 times 25= 1.5

£1.50!