Method and apparatus for producing hollow plastic objects with

Abstract

A method and an apparatus for producing plastic objects with hollow spaces is disclosed. The method comprises the following steps: establishing a fluid connection (9) between the main cavity (2) of a mold (1) and an overflow cavity (8) and injecting a sufficient amount of plastic melt into the cavity (2) of the mold (1) along a melt flow path, which extends from a plasticizing unit (4, 5) through a plastic injection nozzle (3) into the mold (1), such that plastic melt passes from the main cavity (2) into the overflow cavity (8). The fluidic connection (9) between the main cavity (2) and the overflow cavity (8) is then broken-off prior to the introduction of a pressurized fluid, especially a pressurized gas, into the melt in the cavity (2) by means of at least one fluid injection nozzle (7), so that the melt situated in the cavity (2) is distributed in the cavity (2) while forming a hollow space, and is pressed against the cavity walls of the mold (1). The thus formed molded part is then allowed to cool down to a temperature below the melting point of the plastic melt, the cavity pressure is relieved, and the molded part is removed from the mold. The method advantageously achieves the result that the produced molded parts do not have any gas exit openings and the waste in the overflow main cavity (8) remains minimal.