PURPOSE: To provide the subject method comprising: providing a number of grooves on the inner wall of the discharge port of a die to pre-cool the projected parts of the extruded foaming body containing a coloring agent, thereafter introducing the foaming body into a sizing die, pressing the projected parts to smoothen and harden the surfaces of the foaming body thereby to obtain the foaming body having grained patterns.
CONSTITUTION: A coloring agent is mixed in a foaming resin, and the resin is sent to an extruding die 2 through an extruder 1. A plurality of grooves 21 are formed at the inner wall surface of the die 2, and a foaming resin 3A is extruded through a passageway 22. On the surface of the die 2 there are shaped projected parts 21 by the grooves of the die 2 and the resin is led to a pre-cooler 4 and pre-cooled to such a degree as not hardening the projected surface. Then, the resin is introduced into a cooled sizing die 5, and the projected parts 21 are pressed to flatten the surfaces thereof to substantially the same level as the recessed parts 22. Then, by completing the hardening of the resin, the object foaming body 3B having grains consisting of the deep color parts a of a non-foaming body and the light color part b of a foaming body.
ODA SHIGEO
IIJIMA AKIRA
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