Two-Shot (2K) Molding — Two Materials, One Cycle
Two-shot molding injects two materials or two colors into one mold in a single machine cycle. The result is a permanently bonded part — rigid housing with soft-touch grip, a sealed button panel, a two-color logo — with no secondary assembly. It is RUNMULTI’s core specialty.
When 2K Is the Right Choice
- High volumes where removing an assembly step pays back the tooling
- Hard/soft parts needing a strong chemical or mechanical bond
- Two-color cosmetic parts with crisp boundaries
- Integrated seals and gaskets
Where 2K Projects Fail — and How We Prevent It
Most 2K problems are designed in: incompatible material pairs, poor shut-off between shots, flash at the soft-material edge, or warpage from uneven shrinkage. Our DFM checks material compatibility, the shut-off geometry, wall transitions and mechanical interlocks, so the first samples bond properly.
Common Material Pairs
PC + TPE · ABS + TPE · PC/ABS + TPU · PP + TPE/TPV · PA + TPE (adhesion-modified grades) · PC + PMMA · two colors of the same resin.
We recommend specific grades for bonding in your quote.
2K vs. Overmolding
For lower volumes, overmolding (two separate molds) often costs less to tool. At higher volumes, 2K usually gives lower part cost and better consistency. We price both options when it’s a close call.
Your Designs Stay Confidential
- We sign your NDA or send our template before you share detailed files.
- [PLACEHOLDER: confirm — files stored only on local workstations and encrypted storage]
- [PLACEHOLDER: confirm — files are never uploaded to public AI or third-party tools; only anonymized text descriptions, and only where the NDA allows]
- [PLACEHOLDER: confirm — files deleted on request after delivery]
- Case studies are published only with the client’s written permission.
[PLACEHOLDER: NDA template PDF download link — template to be reviewed by a lawyer]
Planning a hard/soft or two-color part?