Multi-layer plastic parts can be produced using four-station molds. This method is easy to implement when using recycled materials and barrier layers. The innermost layer is produced at the first station. Then, the mold is rotated 90° to the next station. At this time, the first component was injection molded using the second component. Then, the mold half continues to rotate to the third station, and finally rotates to the fourth station for the final stage of production.
At this time, a protective outer layer or a surface layer of the molded part is injection molded on the part. After the cooling phase, the final multi-layer part is released from the cavity. In a continuous cycle, each time the mold is opened, a final molded part is produced.