Process and apparatus for producing foamed styrenic polymers

摘要

A method and apparatus for producing a styrenic polymer foam profiles is described comprising mixing in an extruder:
- a styrenic polymer composition,
- a chemical blowing agent, e.g. in a quantity of 0.1 to 1.5 %wt related to the weight of the styrenic polymer composition. and
In addition a physical blowing agent is added, e.g. at a quantity of 5*10<Sup>-2</Sup> to 1.6*10<Sup>-1</Sup> mol/Kg of the styrenic polymer composition, and under sufficient pressure and heat to obtain a single phase mixture.

The mixture is then extruded through a shaping tool in order to form a foam, e.g. a foam profile.