Inject Molding Flashcards
1
Q
What is a risk during the melting part of inject moulding
A
- material degradation, polymers might start to break down
2
Q
Explain the process of inject moulding
A
- fed granules through hopper
- forced through barrel by rotating screw
- melted in barrel
- injected into mould
- cools down in mould, at constant pressure
3
Q
At what order number is it justified to inject mould a product
A
100,000
4
Q
Explain what runners, guide pins and gates are used for
A
Runner = ensures uniform distribution of polymers
Guide pins = to ensure proper alignment
Gate = entry point for material to enter mould
5
Q
design considerations when inject moulding
A
- thin walls, to reduce uneven cooling
- draft angles, tapered walls for easy ejection reducing potential damage
- minimise undercuts, for easy ejection
- reduce stress, avoid sharp angles
- shrinkage
6
Q
What is the problem with mould ejected pins
A
They leave marks on the component
