6. When injection molding, the size of the first injection molding product can be slightly larger, so that it can be pressed tighter with another cavity during the second molding to achieve the effect of sealing.
7. Note that during the second injection, will the flow of the plastic impulse the product that has been molded for the first time and deform its plastic position? If this is possible, we must find ways to improve it.
8. The water conveyance arrangement of the two cavities and cores is as full as possible, and is balanced and the same.
9. In 99% of cases, the hard rubber part of the product is injected first, and then the soft rubber part of the product is injected. Because soft rubber is easy to deform.
10. In order to make the two plastics more "sticky", the "stickiness" between the materials and the roughness of the mold surface must be considered. Two-color injection molding has a special TPU; the smoother the mold surface, the tighter they "stick".