Patent ID: 6699422
Filing Date: 2004-03-02
Classification: B29C

Abstract:
Molding process for the production of plastic parts in which the molten molding material is fed, before molding in a mold cavity (KV), into a repository space (A), implemented as a cylinder and communicating with the mold cavity (KV) in such a way that the repository space (A) discharges without transition into the mold cavity (KV), whose volume nearly corresponds with the volume of the mold cavity (KV), and the molding material is conveyed out of the repository space (A) into the mold cavity (KV) by means of a piston (S) which is axially displaceable in the repository space (A), characterized in thatat the beginning of the injection process, the piston (S) is at a first dead center, at which the bottom of the piston aligns with the edge of the repository space (A) and with the wall of the mold cavity in such a way that a small amount of molding material melt reaches the mold cavity (KV) directly, the piston (S) then slides into the cylinder and the repository space (A), which becomes larger continuously, is filled with molding material melt at almost no pressure until the piston (S) reaches its second dead center position and the supply of the molding material melt is ended, the piston (S) is then moved almost to the first dead center position and the mold cavity (KV) is thus completely filled with molding material, and during the dwell time, the piston (S) is brought into the first dead center position.