1.15 Polymer Processes Flashcards
1
Q
State two features of vacuum forming
A
- Moulds are relatively easy to make but need a draft angle, air holes, and rounded corners
- Not cost effective for one-off manufacture
- Small-scale batch and mass production
2
Q
State two features of thermoforming
A
- Like vacuum forming, except an additional mould is pressed on the surface of the polymer sheet at the same time as the vacuum is applied
- Good for fine details such as moulding in logos
- Slow process, used in industrial production
3
Q
State two features of calendering
A
- Heated rollers squash and stretch the polymer to make it thinner
- Industrial production method, carried out by specialist manufacturers
- Used for continuous production
4
Q
State two features of line bending
A
- Uses an electrically heated element that provides heat along a line
- Quite slow and labour intensive used in school or college workshops
- Suitable for one-off or limited batch production
5
Q
State two features of lamination (lay-up)
A
- Requires a former to mould around
- Polyester resin used as the polymer
- A top gelcoat is applied which may contain pigment
- CFRP requires an autoclave for the product to ‘cure’
6
Q
State two features of injection moulding
A
- Complex 3D shapes can easily be made
- Fast industrial production method
- High initial tooling cost
- Used for large-scale mass or continuous production
7
Q
State two features of blow moulding
A
- Produces hollow thin-walled components
- High initial tooling cost
- Used for continuous production
8
Q
State two features of rotational moulding
A
- Seamless hollow components with a large wall thickness
- Mould continuously rotated through heating and cooling
- Large-scale batch or mass production
9
Q
State two features of extrusion
A
- Like injection moulding expect polymer is forced through a die
- Industrial production method
- Continuous position
10
Q
State two features of compression moulding
A
- Uses a pre-weighted ‘slug’ of polymer
- Polymer removed from moulds
- Large-scale batch production
