Processing
Moulding Process
Production of foam products requires that the raw material be conditioned prior to the final “tooled” moulding process. The raw material has a spherical shape and looks like sugar.
The conversion process has three stages:
Pre-Expansion
Tiny spherical polystyrene beads are expanded to about 40 times their original size using a small quantity of pentane (typically 5% by weight) as a blowing agent. This process involves the heating of beads, using a flow of steam, which causes the blowing agent to boil and thus a honeycomb of closed cells is formed.
Maturing
As the material cools, the pentane liquefies and a partial vacuum is formed inside the bead. The beads are returned to a holding silo for approximately twelve hours to allow the pressure differential to equalize, giving a stabilised granule.
Final Forming
In this final stage the pre-expanded stabilized beads are reheated with steam after being injected into an aluminium moulding tool. The final expansion takes place and the beads coalesce to give a shaped moulding. This can also be used to form large blocks which can be sectioned to the required shape as panels, boards, cylinders etc. In this final form the EPS is made up of 98% air.
Dual Density Moulding
A dual density can be moulded in if your part requires additional strength.
A dual density moulding can offer you:
- Better durability
- Cost savings
- Different properties & qualities where needed
- Enhanced protection and shock absorption in specific areas within a moulding
Insert Moulding
First choice solution where fixtures and fittings need to form a secure and integral part of the final product.
- Far stronger than adhesive processes
- Utilises a shuttle press for H&S reasons
- Parts moulded in to form a one piece moulding
- Insert moulding components (not limited to)
- Metal fixtures and fittings
- Plastic pipe, nozzles
- Vac formed plastic
