PROCESS FOR PRODUCING MOLDED STRUCTURAL FOAM ARTICLE HAVING A SURFACE THAT ODUCIBLY AND FAITHFULLY REPLICATES THE SURFACE OF THE MOLD

摘要

PROCESS FOR PRODUCING MOLDED STRUCTURAL FOAM ARTICLE HAVING A SURFACE THAT REPRODUCIBLY AND FAITHFULLY REPLICATES THE SURFACE OF THE MOLD A process is disclosed for producing a structural foam article having a surface that reproducibly and faithfully replicates the surface of the mold within which the article was made. The process is an improvement in the "low pressure" process for producing structural foam, wherein the improvement resides in introducing the molten mixture of foamable thermoplastic material and blowing agent into the mold under such conditions that a no-slip boundary condition is maintained at an interface between the flowing thermoplastic and a predetermined portion of the interior surface of the mold, and by maintaining the temperature at said interface at or above a certain temperature (termed "replication temperature"), while the thermoplastic is flowing in the mold.