Patent ID: 9186955
Filing Date: 2015-11-17
Classification: B29C,B29K,B29L,B60H,Y10T

Abstract:
1. A process for producing a blow-molded foam used for a climate control duct for vehicles including foamed cells having a flat shape in a direction orthogonal to a thickness direction of a wall defining the blow-molded foam, where an average cell diameter of the foamed cell in the thickness direction of the wall is 56 μm or more and less than 300 μm, and a standard deviation of a cell diameter of the foamed cell in the thickness direction of the wall is less than 40 μm, the process comprising: kneading a polyolefin-based resin having a melt flow rate of 1 to 10 g/10 min at 230° C. and containing a foaming agent mixed therewith in an extruder, wherein the polyolefin-based resin includes a propylene homopolymer having a long-chain branched structure; retaining the polyolefin-based resin at a cylinder-shaped space defined between a mandrel and a die outer cylinder; and extruding a parison between split mold blocks from a die slit at a extrusion rate of 700 kg/h or more by use of a ring-shaped piston after a predetermined amount of the resin is retained at the cylinder-shaped space and carrying out blow molding after clamping by blowing air on the parison at a pressure of 0.05 to 0.15 MPa.