Method For Manufacturing Molded Article With Core

Abstract

A method for manufacturing molded articles with cores uses a compression molding apparatus that includes upper and lower punches that have a double structure comprising a central punch and an outer punch that surrounds the periphery of the central punch. The central punch and the outer punch are movable and capable either of moving together or sliding with respect to one another. Molding materials are supplied for a core and an outer layer. The molding materials are compressed by the punches to form molded articles that include the core. The method may be executed in a rotary compression molding machine.

1 . A method for manufacturing a molding with a core using compression molding means that comprises an upper punch and a lower punch which are arranged in the vertical direction of a die, wherein both the upper punch and the lower punch have a double structure comprising a central punch and an outer punch surrounding the outer periphery of the central punch, wherein both the central punch and the outer punch are capable of compressing operations as well as sliding motions, the method comprising following steps in this order:
 an outer layer supply step 1 of supplying a molding material for outer layer into a space above the lower central punch enclosed by the lower outer punch with the lower central punch being in its lowered position;   an outer layer molding step of compression-molding the molding material for outer layer by moving the upper central punch and the lower central punch toward each other;   a core supply step of supplying a molding material for core into a space above the molding material for outer layer supplied in the preceding step enclosed by the lower outer punch with the lower central punch being in its lowered position;   an outer layer and core molding step of compression-molding the molding material for outer layer and the molding material for core supplied in the precedent steps by moving the upper central punch and the lower central punch toward each other;   an outer layer supply step 2 of supplying a molding material for outer layer into a space in a die above and around the outer layer and core molding formed in the precedent step so as to allow the core molding to completely be enveloped by the molding material for outer layer and the outer layer molding; and   a whole molding step of compression-molding the outer layer and core molding and the molding material for outer layer by moving the upper punch and the lower punch toward each other.   
     
     
         2 . The method for manufacturing a molding with a core according to  claim 1 , wherein a residual molding material removing step of removing molding material residue left on the lower outer punch is effected after the supply of molding material or during compression molding thereof or after the compression molding thereof, excepting most recently supplied molding material for outer layer. 
     
     
         3 . The method for manufacturing a molding with a core according to  claim 2 , wherein the molding material used is in the form of powder or granules. 
     
     
         4 . The method for manufacturing a molding with a core according to  claim 3 , wherein the molding includes plural cores, and wherein the method further comprises, after the core supply step of supplying a molding material for core, outer layer/core repeated supply steps of supplying a molding material for core or a molding material for outer layer into a space above the molding material supplied in the preceding step enclosed by the lower outer punch with the lower central punch being in its lowered position and, each time after the outer layer/core repeated supply steps, an outer layer/core repeated molding steps of compression-molding the molding material(s) supplied in the precedent steps by moving the upper central punch and the lower central punch toward each other. 
     
     
         5 . The method for manufacturing a molding with a core according to  claim 4 , wherein the molding has cores including microcapsular granule and microcapsular granule is used as the molding material for core, and wherein outer layer supply step and microcapsular granule (as molding material for core) supply step thereafter are effected as core outer layer/core repeated supply steps. 
     
     
         6 . The method for manufacturing a molding with a core according to  claim 2 , wherein the molding includes plural cores, and wherein the method further comprises, after the core supply step of supplying a molding material for core, outer layer/core repeated supply steps of supplying a molding material for core or a molding material for outer layer into a space above the molding material supplied in the preceding step enclosed by the lower outer punch with the lower central punch being in its lowered position and, each time after the outer layer/core repeated supply steps, an outer layer/core repeated molding steps of compression-molding the molding material(s) supplied in the precedent steps by moving the upper central punch and the lower central punch toward each other. 
     
     
         7 . The method for manufacturing a molding with a core according to  claim 6 , wherein the molding has cores including microcapsular granule and microcapsular granule is used as the molding material for core, and wherein outer layer supply step and microcapsular granule (as molding material for core) supply step thereafter are effected as core outer layer/core repeated supply steps. 
     
     
         8 . The method for manufacturing a molding with a core according to  claim 1 , wherein the molding material used is in the form of powder or granules. 
     
     
         9 . The method for manufacturing a molding with a core according to  claim 1 , wherein the molding includes plural cores, and wherein the method further comprises, after the core supply step of supplying a molding material for core, outer layer/core repeated supply steps of supplying a molding material for core or a molding material for outer layer into a space above the molding material supplied in the preceding step enclosed by the lower outer punch with the lower central punch being in its lowered position and, each time after the outer layer/core repeated supply steps, an outer layer/core repeated molding steps of compression-molding the molding material(s) supplied in the precedent steps by moving the upper central punch and the lower central punch toward each other. 
     
     
         10 . The method for manufacturing a molding with a core according to  claim 9 , wherein the molding has cores including microcapsular granule and microcapsular granule is used as the molding material for core, and wherein outer layer supply step and microcapsular granule (as molding material for core) supply step thereafter are effected as core outer layer/core repeated supply steps. 
     
     
         11 . A method for manufacturing a molding with a core using compression molding means that comprises an upper punch and a lower punch which are arranged in the vertical direction of a die, wherein both the upper punch and the lower punch have a double structure comprising a central punch and an outer punch surrounding the outer periphery of the central punch, wherein both the central punch and the outer punch are capable of compressing operations as well as sliding motions, the method comprising following steps in this order:
 an outer layer supply step 1 of supplying a molding material for outer layer into a space for the outer layer above the lower central punch enclosed by the lower outer punch with the lower central punch being in its lowered position;   a step of discharging excess molding material for outer layer out of the die;   an outer layer molding step of compression-molding the supplied molding material for outer layer by moving the upper central punch and the lower central punch toward each other;   a residual molding material removing step of removing molding material residue left on the lower outer punch after the supply of molding material for outer layer or during compression molding thereof or after the compression molding thereof;   a core supply step of supplying a molding material for core into a space for core above the molded material for outer layer enclosed by the lower outer punch with the lower central punch being in its lowered position;   a step of discharging excess molding material for core out of the die;   an outer layer and core molding step of compression-molding the supplied molding material for core and the molded material for outer layer by moving the upper central punch and the lower central punch toward each other;   a residual molding material removing step of removing molding material residue left on the lower outer punch after the supply of molding material for core or during compression molding thereof or after the compression molding thereof;   an outer layer supply step 2 of supplying a molding material for outer layer into a space for outer layer in a die above and around the outer layer and core molding so as to allow the core molding to completely be enveloped by the molding material for outer layer and the molded material for outer layer;   a step of discharging excess molding material for outer layer out of the die;   a whole molding step of compression-molding the whole of outer layer and core by moving the upper punch and the lower punch toward each other; and   a step of taking out the compressed molding.