ARRANGEMENT FOR INTRODUCING A GAS INTO THE CAVITY OF AN INJECTION MOLD FOR PRODUCING A HOLLOW PLASTIC BODY

摘要

An arrangement introduces a metered volume of gas into a cavity filled with a melt of plastic. The cavity is defined by an injection mold for producing a hollow plastic body and the injection mold has an injection channel for introducing the molten plastic into the cavity. The arrangement includes a gas-injection nozzle assembly having a housing mounted in the mold and a member displaceably mounted in the housing so as to be movable between a first position and a second position located in spaced relationship to the injection channel. The housing and the member conjointly define a forward end portion of a nozzle assembly facing into the cavity at a region of the cavity spaced from the injection channel. A conducting channel in the forward end portion conducts the gas into the cavity when the member is in the second position. The conducting channel defines a gas-discharge opening for discharging the gas into the cavity. The gas-discharge opening is freely projected approximately into the center of the region at which the nozzle assembly is located to thereby discharge the gas when the member is in the second position thereof and while the melt is injected into the cavity. A method of introducing the gas is also disclosed.