e.g:
#
A method of impregnating polystyrene beads with an aliphatic hydrocarbon, rendering it into expandable polystyrene. The method involves the use of an ...
www.freepatentsonline.com/4560705.html
#
Impregnating polystyrene beads with an expanding agent - US Patent ...
Patent Claims: A method of impregnating polystyrene beads with an expanding agent to render the beads expandable, comprising the steps of preparing an ...
www.patentstorm.us/patents/4560705/claims.html

#
A method for production of expandable polystyrene beads by supplying a polymer melt flow and an expanding agent flow to a mixing zone, dispersing the ...
www.faqs.org/patents/app/20080203597 - 46k - Cached - Similar pages
#
Process for the production of extruded sheets of expanded ...
Typically, the desired density of the expanded polystyrene for use as insulating ... as it is obtained in fact if only CO2 is used as expanding agent, ...
www.freshpatents.com/Process-for-the-production-of-extruded...



--------------------------------------------------
Note added at 1 hr (2009-03-30 16:33:30 GMT)
--------------------------------------------------

Bitte um Entschuldigung, ich habe die Sprachrichtung nicht richtig gelesen. Der englische Beitrag ist somit ungültig.