Patent ID: 8728363
Filing Date: 2014-05-20
Classification: B29C,B29K,B29L

Abstract:
1. A process for producing a wide thermoplastic resin foam having a width to thickness ratio of at least 100, comprising: feeding a molten foamable thermoplastic resin through a manifold having multiple symmetrically bifurcated flow paths that terminate in a plurality of coat-hanger-shaped flow paths at downward ends thereof, extruding the molten foamable thermoplastic resin as foamed strands through delivery apertures formed in a plurality of die plates, the die plates being disposed at downward ends of the plurality of coat-hanger-shaped flow paths and arranged corresponding to said respective coat-hanger-shaped flow paths, and coalescing said foamed strands together, wherein: in each of said plurality of die plates, the delivery apertures disposed on opposite side regions have a diameter (α) and the delivery apertures disposed in a center region of each die plate have a diameter (β), whereby (α) is greater than (β), and so as to provide a uniform flow rate of the molten foamable thermoplastic resin in a width direction on downstream sides of said coat-hanger-shaped flow paths, wherein said plurality of die plates satisfy the following condition whereby: W wherein in each of said die plates, the ratio (α/β) of the diameter (α) of said delivery apertures in said opposite side regions to the diameter (β) of said delivery apertures in said center region is 1.05 to 1.40, and wherein in each of said die plates, said delivery apertures in said opposite side regions are located within ranges of 30%, based on a width of said die plate, from opposite side edges of said die plate.