Process of extruding polysulfone foam
AssigneePackaging Industries Group, Inc.
InventorDennis A. Knaus
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Abstract
A method for the preparation of polysulfone foam using methylene chloride as a blowing agent. A pressurized combination of heat-plastified foamable gel of polysulfone containing methylene chloride as a blowing agent is extruded into a zone of lower pressure through an orifice of a die. As the gel expands into a foam, it forms a product of decreased density, increased resiliency and flexibility, and improved insulation properties over conventional polysulfone foam.
Claims13
In a process for producing a polysulfone foam, the steps of mixing a polysulfone polymer with a volatile organic blowing agent under sufficient heat and pressure to form a flowable gel and releasing said pressure to convert said flowable gel into a cellular mass, said blowing agent comprising methylene chloride.
In a process for producing a polysulfone polymer foam, the method which comprises the steps of mixing and kneading a polysulfone polymer with a volatile organic blowing agent under conditions of heating and pressure to form a flowable gel and, thereafter releasing the pressure by extruding out said gel, the improvement wherein said blowing agent comprises methylene chloride.
Dependencies are inferred from the claim text.