Fusible core injection molding

The lost-core molding is a special process of plastic injection molding. It is used for producing molded parts with cavities or undercuts that would not be possible with tools with demoldable cores.

Description

The procedure consists of three main steps. First, it is poured from a low-melting metal a core which corresponds to the forming cavity in the form prescribed part. This is inserted in the second step in the injection mold and sprayed with plastic. Molding and core are removed from the mold and placed together in the third step in a heating bath to melt out the core. The bath temperature is set slightly higher than the melting point of the core alloy, so that the molded part is not damaged. By inductive heating of the core metal in the heating bath, the Ausschmelzzeit reduced to a few minutes. Liquid core metal collects at the bottom of the heating bath and is available for new cores.

Application

The use of core melting process is not limited to injection molding of thermoplastics, but with corresponding core alloys on thermosetting molding compounds ( thermosetting plastics ). Application finds the lost core process, for example, for injection-molded intake manifolds of car engines. Can be obtained by modifying the system in the meantime, however, also produce small parts, such as valves or the pump housing, by the preparation of the cores, and melting the molded parts is carried out in an injection molding machine.

• Special injection molding