Structural foam moulding (also known as low-pressure foam moulding) allows some of the disadvantages of high-pressure injection moulding to be overcome. The main difference is that a chemical blowing agent is added to the plastic granules. This becomes active when the plastic is melted.
Less internal stress means a lower risk of deformation
Until the plastic has hardened, the foam injected into the mould continues to expand. This means the internal pressure on the cooling plastic is evenly distributed, reducing the internal stress in the finished product.
Advantages of structural foam moulding:
- Reduced risk of deformation
- Thicker walls possible
- More options for walls with different thicknesses
- Greater freedom in terms of design compared with high-pressure injection moulding
Common product wall thicknesses:
- 3 to 8 mm
Points to consider with structural foam moulding:
- ‘Foamed’ finish
- May be necessary to paint the product