Product with Internal Undercuts

Products with internal undercuts (e.g., threaded closures, housings with a retracted edge, parts with snap-in noses. 

There are two basic ways of joining the hard and soft components of a composite, chemical and mechanical [14], A purely mechanical joint is obtained by overmolding apertures or undercuts in the hard component. The use of internal or external adhesion promoters permits the production of composites with liquid-tight frictional joints [15], A bond formed by chemical cohesion has a number of advantages over a mechanical joint formed by interlocking [16] ... 

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