Patent ID: 6143237
Filing Date: 2000-11-07
Classification: B29C

Abstract:
A method for producing plastic molded parts with solid regions and hollow spaces, comprising:blocking off a portion of a cavity of a molding tool;injecting plastic melt into an unblocked portion, but not a blocked-off portion, of the cavity of the molding tool along a melt flow path, which extends from a plasticizing unit through a plastic injection nozzle into the molding tool;injecting the plastic melt until the unblocked portion of the cavity is filled with plastic melt;unblocking the cavity enabling the plastic melt to reach the previously blocked-off portion of the cavity;simultaneously and/or subsequently to injecting the plastic melt, injecting a pressurized fluid into the melt via at least one fluid injection nozzle, so that the melt injected into the molding tool is distributed in the cavity;forming a hollow space in the unblocked portion of the cavity by pressing the melt against cavity walls of the molding tool;forming a substantially solid plastic section in the previously blocked-off portion of the cavity;allowing a molded part thus produced to cool down to a temperature below the melting point of the plastic melt;relieving the cavity of the pressure of the pressurized fluid; anddemolding the molded part.