Patent ID: 6387309
Filing Date: 2002-05-14
Classification: B21D,B23P,B32B

Abstract:
A method of manufacturing a press die made of concrete, including a concrete body and a surface layer bonded to a pressing surface of said concrete body, said method comprising:placing a retardation means in a casting mold for the press die; filling an unhardened concrete in said casting mold above said retardation means, said unhardened concrete including an aggregate; naturally hardening said concrete to form a hardened concrete member; removing the hardened concrete member from said casting mold; washing a portion of the hardened concrete member contacting said retardation means to expose aggregate on a surface of said hardened concrete member; steam-curing said hardened concrete member; returning said hardened concrete member to said casting mold; forming a surface layer on the aggregate exposed surface of said hardened concrete member while said hardened concrete member is within said casting mold; and removing said hardened concrete member with said surface layer thereon from said casting mold.