They are filled with a physical foaming agent which is encapsulated in a polymeric shell and strongly expands under the influence of heat while keeping the increased volume during cooling.
There are diverse fields of application, e.g. TPU-shoe soles, coatings, underbody coatings (UBC), wall coverings, insulation materials and silicone rubber (LSR and HTV). By using MS, very low densities and highly homogeneous, closed cell foam structures can be produced (see photo).
TRAMACO offers a wide range of expandable microspheres as powder (e.g. for plastisols) and polymer-bound masterbatches in granulated form (e.g. for injection molding applications).
In some applications an optimal result can be reached by combining microspheres and conventional chemical foaming agents. Appropriate TRACEL®-Types are available for such applications.
Already 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, e.g. paints, lacquers, coatings or thermosets.