Tramaco launches expandable microspheres for TPE, silicone rubber

German chemical manufacturer Tramaco GmbH (Tramaco) has launched new expandable microspheres that enable the production of very low density, highly homogeneous closed cell foam structures for use in diverse fields of application. Tramaco said that the microspheres could even be combined with conventional chemical foaming agents for optimal results in certain applications.

Unlike materials such as TPE/TPU that cannot be processed by chemical or physical foaming due to their low melt strength, Tramaco’s microspheres are filled with a physical foaming agent which is encapsulated in a polymeric shell and strongly expands under the influence of heat and keeps its increased volume during cooling.

Pre-expanded microspheres are brand-new in Tramaco’s portfolio: by application of these ultra-light fillers, with densities below 30 kg/m³, cell structures can also be created in materials which do not allow expandable microspheres or conventional chemical foaming agents in their processing operations.

The expendable microspheres can be used in the production of TPU-shoe soles, coatings, underbody coatings (UBC), wall coverings, insulation materials and silicone rubber (LSR and HTV). The product is also offered as powder (e.g. for plastisols) and polymer-bound masterbatches in granulated form (e.g. for injection moulding applications).