Expanded polypropylene (EPP)

The foam produced from polypropylene (PP) is elastic, shock-proof and has a particularly pleasant feel. It is used in a range of hardness levels for the production of training shoes, car seats and even furniture, for example, to guarantee a soft landing. EPP is also popular for high-quality thermal insulation packaging and shock-proof packaging.

Suspension stabilisation

In contrast to the styrene in the EPS process, propylene is directly polymerised and then granulated. In order to make the resulting PP granules expandable, they are suspended in water via pressure and a high temperature, and impregnated with a foaming agent. After this step, the resulting EPP granules can be processed further in the same way as EPS beads. Injected into hollow moulds, the beads are foamed and welded at an elevated temperature to create EPP moulds, which, in contrast to the refractory EPS moulds, are particularly elastic.

Phosphates produced by Budenheim serve as suspension stabilisers in this process. The polymer surface becomes viscous and sticky through the increased temperature and contact with the foaming agent. The addition of phosphates is the only way of preventing the PP particles from forming lumps and of avoiding the time-consuming and complex cleaning of reactors. Based on their high quality and the stability of their chemical and physical composition, Budenheim phosphates are particularly suitable for supporting sensitive procedures in the EPP process without causing any detrimental effects.