1. Soft and hard plastic two-color design
The two materials must have a certain temperature difference in the melting point. Generally, it is recommended to reach 60°. It is recommended to be at least 30°. The melting temperature of the first shot material is high. Generally, the first shot is PC or PC/ABS, and the second shot is TPU or TPE, PC thickness is 0.6-0.7mm, soft rubber part thickness is required to be 0.4mm or more.
Try to widen the contact area, make grooves to increase the adhesion, or use the core for the first shot, and the second part of the material is injected into the first shot. The surface of the first shot is as rough as possible.
2. Material compatibility
Multi-color injection molded mating materials must meet two basic compatibility conditions. They are compatible with the adhesive compatibility and processing.
3. Transparent and non-transparent two-shot design
(1) Double shot design of small lenses
The first shot is non-transparent, and the second shot is made of a lens. The first shot uses a PC with a high melting point and the second shot uses a PMMA.
(2) Transparent and non-transparent bijective design for decoration
The first shot is a non-transparent material, the second shot is a transparent material, and the non-transparent material is generally a high temperature of the PC material of SABIC, and the second shot transparent material is PMMA or PC. The PC needs to be sprayed with UV to protect it. PMMA can choose uv or fortification. If there are characters on the surface, you must choose UV.