Foaming of plastics in injection moulding

Thermoplastic foam injection moulding produces a foamed core with hollow spaces with a compact part surface. This allows you to reduce the weight and material usage while maintaining the mechanical properties of your part.

Physical or chemical foaming generates an internal pressure within the part. This effectively counteracts any warping or shrinkage and prevents sink marks. You obtain dimensionally stable parts and reduce rejects - particularly advantageous for parts with complex geometries.

Another advantage of foaming plastics in injection moulding is the lower internal part pressure. Clamping force and injection pressure can be reduced compared to the standard injection moulding process. You benefit from lower energy costs, reduce your CO2 emissions and protect your mould and injection moulding machine. For large, flat parts, you can often even switch to a smaller injection moulding machine.

One effect of foaming plastics in injection moulding: the escaping gases create streaks on the surface of the part. However, visible parts can easily be upgraded to high-quality and even functionalised surfaces using the following ENGEL processes:

• ENGEL foilmelt

• ENGEL variomelt

• Gas counter pressure technology

Thanks to our in-house development and production of plasticising components, we can offer you screws specially developed for physical and chemical foaming. Benefits include higher process stability, optimum melt quality and increased plasticising performance.