Process for producing extruded foam products having polystyrene blends with high levels of CO2 as a blowing agent

摘要

In one embodiment, the present invention relates to a process for preparing foam board or sheet including the steps of (A) forming a foamable mixture of (1) a major amount of a styrenic polymer having a high melt index, (2) a minor amount of a low melt index styrenic polymer, and (3) a blowing agent containing a major amount of carbon dioxide under a pressure sufficient to prevent prefoaming of the mixture, and (B) foaming the mixture into a region of reduced pressure to form a foam product.