Stabiliser Requirements
Stabiliser systems used in the extrusion
of foamed PVC are designed to offer control over the foaming process
in addition to the standard requirements for steels. The large surface
areas need special attention to ensure correct melt flow behaviour and
good colour control.
On top of these requirements processing
for foamed profiles and sheets require stabilisers which harmonise well
with the used organic and/or inorganic foaming agents. It is necessary
to give the foaming process the proper "kick" to obtain an
even foam structure without surface deficiencies or mechanical weak
points. Furthermore the achieved overall density has to be low in order
to provide lightweight use and economic processing.