초록 ▼

Hot runner injection molding apparatus for coinjecting two thermoplastic materials sequentially through separate channels to form at least a two-layer sandwich material is provided. There is a valve means for instantaneously switching the flow of thermoplastic material from one channel to the other

Hot runner injection molding apparatus for coinjecting two thermoplastic materials sequentially through separate channels to form at least a two-layer sandwich material is provided. There is a valve means for instantaneously switching the flow of thermoplastic material from one channel to the other channel, the valve means preferably comprising a shuttle ball member.

대표청구항 ▼

A method of coinjecting two thermoplastic materials to form a two or more layer member using a hot runner injection molding machine with two separate channels, one channel for each material, each channel having an exit end that opens into a common exit cavity having a common gate entrance to an inje

A method of coinjecting two thermoplastic materials to form a two or more layer member using a hot runner injection molding machine with two separate channels, one channel for each material, each channel having an exit end that opens into a common exit cavity having a common gate entrance to an injection mold, the method comprising of: A. heating the thermoplastic materials in the two channels; B. injecting material from the first channel through the common gate into the injection mold; C. simultaneously forcing a valve member to seat itself in the exit end of the second channel to prevent intermixing of the two materials; D. sequentially injecting material from the second channel through its exit end into the common exit cavity and into the common gate entrance; E. simultaneously stopping the flow of material into the common exit cavity by forcing the valve member into the exit end of the first channel to seat itself therein; and F. simultaneously cleaning the first material from the exit cavity and the gate entrance by forcing the valve member and the first material into the exit end of the first channel.