Overmoldingis a process where a second material is molded over a rigid substrate to create a single integrated component.

First shot: rigid plastic (PC, ABS, Nylon)
Second shot: soft material (TPE, TPU, silicone)

Benefits:
Improved grip and ergonomics
Better sealing performance
Enhanced product appearance
Reduced assembly and labor cost

Overmolding sounds simple: mold one material, then mold another over it. But anyone who's tried it knows the real challenge:

Weak bond between layers?
Flash creeping where it shouldn't?
Shrinkage mismatch causing warpage or stress cracks?
We've solved all of these – across thousands of molds.

At Winzun, overmolding is a science, not an art. We analyze material compatibility (TPE/TPU/TPV on PC/ABS/PA), optimize wall thickness and gate location, and run molding simulations to predict how the two materials will behave together – before we cut steel.

The result: parts that stay bonded, stay clean, and stay functional – over millions of cycles.