PREPARATION OF POLYSTYRENE RESIN FOAM MOLDINGS

摘要

PURPOSE:To obtain resin foam moldings without occurrence of crack or rupture by carrying out bend-processing using a specific volatile foam agent while the foam contain more quantity of a foam agent than the specific one. CONSTITUTION:A volatile foam agent with a SP value of 7.0-9.1 is added into polystyrene resin and the resultant mixture is melted and kneaded in an extruder. After extruding this material from the extruder under a low pressure and foaming it, bend-processing is carried out under the condition that the foam agent with a SP value of 7.0-9.1 remains more than 0.5mol% in 1kg of the foam. In this state, the foam is softened and can be easily bent to process. After the bend-processing, the foam molding is gradually cured and finally comes to have a superior mechanical strength.