Injection moulding of hollow items with internal gas pressure - has process efficiency improved by injecting cooling fluid into gas-filled product cavity

摘要

An injection moulding tool (10) has a cavity (1) and an inlet nozzle (3) for a polymer (2). The polymer fills at least part of the cavity (1). A second component, typically a gas is injected through a co-axial or side wall injector (4) and forces the polymer (2) against the cavity walls (1) and creates a hollow cavity. Rapid cooling is achieved by introducing a cooling fluid into the gas-filled hollow cavity (7). The cooling fluid is supplied and extracted through an injector nozzle (9) which is pushed through the plastic component wall, during or after forming, and into the gas-filled hollow cavity (7). One or more injectors (9) can be used according to component size. USE/ADVANTAGE - For producing gas-filled hollow components. Improves cooling, reduces demoulded time and hence process efficiency, especially with larger components.