Over Mold Manufacturer

Overmold Design Considerations

Bonding: In a perfectly overmolded part, the overlay is impossible to remove, and will tear before separating from the substrate, or even take some of the underlying material with it. Achieving a high-level chemical bond isn’t always possible, we have to evaluation of material bonding and mechanical bonding of dissimilar materials. Adhesion between the substrate and the over molded part is usually necessary to proper fit and function of the final product. Preheating the substrate might be necessary to bring its surface temperature closer to the melt temperature of the over mold, so as to reach optimum bond strength between the two materials. In most cases, we have to use mechanical interlock to augment or even replace a chemical bond. This can be achieved by placing an undercut in the substrate part, or a series of reverse-tapered or counterbored holes into which the overmolding material can flow, assuring a no-fail mechanism in all but the most demanding applications.

适当的草案角度、壁厚均匀和年代mooth transition lines must be maintained in both parts.
The thickness of the overmold material should be less than or equal to that of the substrate below it.
The melting temperature of the overmolding material should be less than that of the substrate (as in our LSR example).
Texturing of the substrate workpiece may help with adhesion. Texturing of the overmolded part may provide a better grip and more attractive surface.
The surface of the overmolded part should be even with or slightly below any adjacent substrate surfaces.