| 摘要 |
PURPOSE:To obtain a mold simple in structure, easy to change indications of manufacture and mold history, poor in burrs and low in cost by a method wherein hollows are formed on the cavity side of the mold and charged with low melting point alloy and historical indications such as figures etc. are engraved on the surfaces thereof. CONSTITUTION:Hollows 6 for indication are formed on the prescribed positions to indicate the history of a molded piece on the cavity side 2 of a metal mold 1 to mold high molecular material such as rubber, synthetic resin, etc. and said hollows 6 are charged with low melting point alloy 7 (such as Wood's alloy etc.) higher in melting point than molding material in molding time as it is melted, cast and cooled and historical indications B such as figures, marks, etc. are engraved by a taken etc. to obtain the desired mold. Undercuts 8 or female thread 9 can be provided on the inside walls of the hollows 6 for indication so that the low melting alloy 7 does not separate easily from the hollows 6 for indication. |
