The sandwich injection molding process injects a core material into the outer skin. The process takes place in two or three steps in one cavity. First, the material of the stroke surface layer is injected into the cavity portion space. The core component is then injection molded through its first material into its internal center. Finally, the first component is sealed at the gate location.
In this way, the core material can be prevented from appearing on the surface, and at the same time, the second component in the gate system can be removed for the first injection of the first component.
A common application situation is that the molded part needs a beautiful appearance, and the core needs to use recycled materials, or the technical parts need a hard core, and the surface layer needs to be improved to obtain a better part feel. It is also possible to produce molded parts with stylish features such as a colored core with a transparent surface.