Patent ID: 7255817
Filing Date: 2007-08-14
Classification: B30B

Abstract:
1. A method for compression-molding a cylindrical tablet by using a rotary powder compression-molding machine provided with a die and upper and lower punches fitted to a rotary table, a core punch penetrating the punch end of a lower punch at the center in a horizontal direction of the punch end of the lower punch, the core punch being movable in a sliding direction of the lower punch, and a center hole formed at the center in a horizontal direction of the punch end of the upper punch to allow the insertion of the core punch at the time of compression-molding, wherein the upper and lower punches are moved in their axial directions by upper and lower rollers while the upper and lower punches are passed between the upper and lower rollers with the rotation of the rotary table whereby powder filled in the die is compressively molded, the compression-molding method being characterized by using the core punch in which the difference between the smallest diameter of the core punch at the portion for forming the center opening of the cylindrical tablet and the reference diameter of the portion in design, is within 0.04 mm.