Overmolding Design Tips
Wall thicknesses between 0.060″ to 0.120″ (1.5 mm-3 mm) generally provide the best bonding.
Keeping radii between 0.020″ or 0.5mm minimum in corners reduces localized stresses.
If the part requires thick TPE sections, they should be cored out to minimize shrinkage problems, reduce the part weight, and lower cycle time.
Avoid deep or un-veritable blind pockets or ribs in your design.
Use gradual transitions between wall thickness to reduce or avoid problems with the flow (backfills, gas traps, etc.)
The TPE/TPV should be less thick than the substrate to prevent warpage, especially if the part is flat, long, or both.
Overmolding needs mechanical or chemical bonding to the substrate, so your material choices should enable this.