FREMGANGSMAADE TIL FREMSTILLING AF STYRENPOLYMERSKUM OG SKUM FREMSTILLET DERVED

摘要

A styrene polymer foam is produced, which foam is more environmentally acceptable and can be used to produce insulating foam over a wide density interval, which foam is decorative and does not require modification of existing equipment for high-pressure operation using a mixed blowing agent consisting of carbon dioxide plus ethyl chloride and, where appropriate, a fluorocarbon for producing a foam which possesses primary cells and secondary cells and which is delimited by the stiffeners and the walls. The production process comprises heat- plasticizing the styrene polymer and adding a mixed blowing agent consisting of carbon dioxide, ethyl chloride and, where appropriate, a fluorocarbon to the heat-plasticized polymer under a pressure which is sufficiently high to prevent foaming, reducing the temperature of the mixture and reducing the pressure of the mixture when it is extruded in order to form the foamed product.