Why this matters
Know which substrate resins bond reliably to which TPE or TPU grades, and when mechanical retention features matter more than chemical bonding. Buyers get better quotes when they describe the part function, material assumptions, quantity, quality expectations and the decision they need to make next.
Practical checklist
Next step
Use the quote form to send the minimum useful details. A first review can identify whether the part is ready for tooling discussion or still needs design cleanup.
Practical takeaway
Chemical bonding between the overmold and substrate depends on grade-specific compatibility, not just the general resin family: PP substrates usually pair with a PP-bonding SEBS TPE, ABS and PC both bond well with many standard TPE/TPU grades, and nylon needs a specialty amide-compatible TPE since standard grades will not bond to it at all. Where chemical bonding is weak or unconfirmed, mechanical retention features (through-holes, undercuts, texture on the bonding surface) can hold the overmold in place even without a strong chemical bond, and a peel test on an actual prototype is the only reliable way to confirm a given grade pairing before committing to tooling.
How to apply this guide
Use this guide as a preparation step before asking for mold price or production lead time. A stronger RFQ names the current project stage, the file format available, the expected first order, the annual volume, the target resin and the approval evidence needed after T1 samples.
If the project is still early, the guide can also show whether the next move is design cleanup, rapid tooling, production mold planning, material selection or quality-document scoping. That makes the inquiry more specific and helps the first engineering reply focus on decisions instead of basic clarification.