METHOD AND APPARATUS FOR OVERMOLDING FRAGILE HOLLOW ARTICLE

摘要

A method and apparatus for of overmolding a fragile hollow item with a plastic material. The process comprises providing the fragile hollow item collapsible under a pressure of about 25 MPa and greater and at least partially overmolding the fragile hollow item with the thermoplastic material while maintaining a substantially constant melt pressure of less than about 25 MPa. An apparatus for said process comprises at least two mold parts forming therebetween a mold cavity for receiving the fragile hollow item, an injection device for injecting the thermoplastic material into the mold cavity and over the hollow item, and a pressure-control mechanism for monitoring a melt pressure of the thermoplastic material and adjusting an injection pressure according to a pressure-dominated algorithm based on the melt pressure, wherein the pressure-control mechanism comprises at least one high-frequency pressure sensor located upstream of the mold cavity's front end.