Method of producing powder compacts and foil or film-like mold members for use in the method

Abstract

A powder compact is produced by disposing a foil or film-like mold member packed with a powder in a cavity of a rubber mold which is loaded in a die. The rubber mold, the foil or film-like type mold member and the powder packed in the foil or film-like mold member are compressed by a punch to obtain a powder compact. The powder compact with the foil or film-like mold member being attached thereto is removed, by pressure, from the rubber mold. Since the powder to be compressed into a compact is not packed directly in the cavity of the rubber mold, but is packed in the mold member, no part of the rubber mold is caught in the space formed by the powder that is in contact with the rubber mold. Accordingly, cracks and chips in the powder compact can be prevented even when the rubber mold is restored to its initial shape and many shape and size variations of the powder compact can be realized.

1 . A method of producing a powder compact, comprising: 
 disposing a foil or film-like mold member packed with a powder in a cavity of a rubber mold which is loaded in a die;    compressing the rubber mold, the foil or film-like mold member and the powder packed in the foil or film-like mold member with a punch to obtain a powder compact; and    removing the powder compact with the foil or film-like mold member from the rubber mold.    
     
     
         2 . A method of producing a powder compact, comprising: 
 disposing a foil or film-like mold member packed with a powder in a cavity of a rubber mold which is loaded in a die;    compressing the rubber mold, the foil or film-like mold member and the powder packed in the foil or film-like mold member by a punch to obtain a powder compact;    removing the powder compact with the foil or film-like mold member from the rubber mold; and    removing the foil or film-like mold member from the powder compact.    
     
     
         3 . A method of producing a powder compact, comprising: 
 packing a foil or film-like mold member with a powder;    disposing the foil or film-like mold member packed with powder in a cavity of a rubber mold which is loaded in a die;    compressing the rubber mold, the foil or film-like mold member and the powder packed in the foil or film-like mold member with a punch to obtain a powder compact; and    removing the powder compact with the foil or film-like mold member from the rubber mold.    
     
     
         4 . An apparatus for producing powder compacts, comprising: 
 a foil or film-like mold member having an inside portion which is packed with a powder    a rubber mold having a cavity, the foil or film-like mold member being disposed in the cavity; and    a die for receiving the rubber mold, wherein 
 the rubber mold, the foil or film-like mold member and the powder packed in the foil or film-like mold member are compressed by a punch to obtain a powder compact, and  
 the powder compact with the foil or film-like mold member is removed from the rubber mold.  
   
     
     
         5 . The apparatus of  claim 4 , wherein the foil or film-like mold member is removed from the powder compact after the powder compact is removed from the rubber mold.  
     
     
         6 . The method of  claim 1 , wherein the foil or film-like mold member is made of a low melting point metal.  
     
     
         7 . The method of  claim 1 , wherein the foil or film-like mold member is made of a material selected from the group consisting of tin, aluminum, copper, iron, nickel, stainless steel, paper and synthetic resin.  
     
     
         8 . The method of  claim 7 , wherein the foil or film-like mold member is made of a material selected from the group consisting of tin, aluminum, copper, iron, nickel and stainless steel and has a thickness in a range of about 0.01 to 1.50 mm.  
     
     
         9 . The method of  claim 8 , wherein the foil or film-like mold member has a thickness in a range of about 0.03 mm to 1.00 mm.  
     
     
         10 . The method of  claim 1 , wherein the foil or film-like mold member is made of paper or synthetic resin and has a thickness in a range of about 0.05 to 3.0 mm.  
     
     
         11 . The method of  claim 10 , wherein the foil or film-like mold member has a thickness in a range of about 0.1 to 2.0 mm.  
     
     
         12 . The method of  claim 1 , further comprising applying heat to the powder compact with the foil or film-like mold member after it is removed from the rubber mold to melt or remove the foil or film-like mold member.  
     
     
         13 . The method of  claim 1 , further comprising applying heat to the powder compact with the foil or film-like mold member after it is removed from the rubber mold at a temperature below the melting point of the foil or film-like mold member to produce a presintered compact.  
     
     
         14 . The method of  claim 2 , wherein the foil or film-like mold member is made of a low melting point metal.  
     
     
         15 . The method of  claim 2 , wherein the foil or film-like mold member is made of a material selected from the group consisting of tin, aluminum, copper, iron, nickel, stainless steel, paper and synthetic resin.  
     
     
         16 . The method of  claim 15 , wherein the foil or film-like mold member is made of a material selected from the group consisting of tin, aluminum, copper, iron, nickel and stainless steel and has a thickness in a range of about 0.01 to 1.50 mm.  
     
     
         17 . The method of  claim 16 , wherein the foil or film-like mold member has a thickness in a range of about 0.03 mm to 1.00 mm.  
     
     
         18 . The method of  claim 2 , wherein the foil or film-like mold member is made of paper or synthetic resin and has a thickness in a range of about 0.05 to 3.0 mm.  
     
     
         19 . The method of  claim 18 , wherein the foil or film-like mold member has a thickness in a range of about 0.1 to 2.0 mm.  
     
     
         20 . The method of  claim 2 , further comprising applying heat to the powder compact after it is removed from the rubber mold at a temperature to produce a presintered compact.  
     
     
         21 . The method of  claim 3 , wherein the foil or film-like mold member is made of a low melting point metal.  
     
     
         22 . The method of  claim 3 , wherein the foil or film-like mold member is made of a material selected from the group consisting of tin, aluminum, copper, iron, nickel, stainless steel, paper and synthetic resin.  
     
     
         23 . The method of  claim 22 , wherein the foil or film-like mold member is made of a material selected from the group consisting of tin, aluminum, copper, iron, nickel and stainless steel and has a thickness in a range of about 0.01 to 1.50 mm.  
     
     
         24 . The method of  claim 23 , wherein the foil or film-like mold member has a thickness in a range of about 0.03 mm to 1.00 mm.  
     
     
         25 . The method of  claim 3 , wherein the foil or film-like mold member is made of paper or synthetic resin and has a thickness in a range of about 0.05 to 3.0 mm.  
     
     
         26 . The method of  claim 25 , wherein the foil or film-like mold member has a thickness in a range of about 0.1 to 2.0 mm.  
     
     
         27 . The method of  claim 3 , further comprising applying heat to the powder compact with the foil or film-like mold member after it is removed from the rubber mold to melt or remove the foil or film-like mold member.  
     
     
         28 . The method of  claim 3 , further comprising applying heat to the powder compact with the foil or film-like mold member after it is removed from the rubber mold at a temperature below the melting point of the foil or film-like mold member to produce a presintered compact.  
     
     
         29 . The apparatus of  claim 4 , wherein the foil or film-like mold member is made of a low melting point metal.  
     
     
         30 . The apparatus of  claim 4 , wherein the foil or film-like mold member is made of a material selected from the group consisting of tin, aluminum, copper, iron, nickel, stainless steel, paper and synthetic resin.  
     
     
         31 . The apparatus of  claim 30 , wherein the foil or film-like mold member is made of a material selected from the group consisting of tin, aluminum, copper, iron, nickel and stainless steel and has a thickness in a range of about 0.01 to 1.50 mm.  
     
     
         32 . The apparatus of  claim 31 , wherein the foil or film-like mold member has a thickness in a range of about 0.03 mm to 1.00 mm.  
     
     
         33 . The apparatus of  claim 4 , wherein the foil or film-like mold member is made of paper or synthetic resin and has a thickness in a range of about 0.05 to 3.0 mm.  
     
     
         34 . The apparatus of  claim 33 , wherein the foil or film-like mold member has a thickness in a range of about 0.1 to 2.0 mm.  
     
     
         35 . The apparatus of  claim 4 , further comprising a heater for applying heat to the powder compact with the foil or film-like mold member after it is removed from the rubber mold to melt or remove the foil or film-like mold member.  
     
     
         36 . The apparatus of  claim 4 , further comprising a heater for applying heat to the powder compact with the foil or film-like mold member after it is removed from the rubber mold at a temperature below the melting point of the foil or film-like mold member to produce a presintered compact.