TPE secondary injection molding typically utilizes TPE's soft-touch feel to produce items such as handles, gun stocks, fitness equipment, and tool handles. The TPE overmolding is usually quite thin, generally between 0.5-2 mm. However, in many cases, the hard plastic component of the TPE overmolding has a very complex structure. To achieve optimal secondary injection molding results, the following factors should be considered in the secondary injection molding process:

1. Compatibility between TPE and the hard plastic prefabricated component needs to be matched; the molecular structures should have similar solubility for better molecular compatibility;

2. Sharp corners should be minimized in the design to ensure good contact between the TPE and the hard plastic component, improving adhesion;

3. Use appropriate vents to prevent gas from being trapped in the mold cavity;

4. Balance the TPE thickness with the desired feel;

5. Maintain the temperature of the TPE melt to ensure adhesion;

6. TPE material overmolding requires drying and reprocessing to reduce surface waviness and achieve a uniform surface color;

7. The chosen plastic masterbatch's medium epoxy resin must be compatible with both the TPE and the component material;

8. Smooth surfaces require special treatment to increase the surface area of the TPE and the hard plastic component for better adhesion;

9. TPE should have good fluidity, as the TPE overmolding layer is relatively thin and small; the TPE generally needs to flow through a longer path and thicker areas to fill the mold.

10. The TPE fluidity length/product thickness ratio should be less than 150:1. A larger ratio may result in insufficient material and unsatisfactory overmolding;

11. Use a good adhesive.