Design of Pin-Point Gate Injection Mould for Shells of Earplugs

The whole design scheme of injection mould for shells of earplugs was determined by analyzing its structure and injection molding technology. In order to adapt to the high product batch and high requirement for appearance quality, an angle ejector of injection mold side core pulling was designed. The layout of a type of pin-point mould with one module and four cavities was determined. The selection of parting surface, the calculation of the cavity number and layout, mold core and cavity design and the design of cooling system were mainly introduced. This paper introduces the structure and working principle of the injection mould for the earplug shell in details. The automatic demoulding of the pouring material is realized. The mold structure is compact which reduces the cost of die manufacturing. It has been proved by practice that the mould is reasonable in structure and the quality of plastic part is stable and has good economic benefits.