Mechanical bonding undercuts

Section 11.5. will explain the three alternatives for bonding, where mechanical anchorage (undercuts) or self-adhesive silicone rubber allow for two colour injection moulding. 

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] ... 

Anchors without end plates (Fig. 11) consist of a metallic profile that is embedded in the masonry and can transmit loads to the substratum by mechanical locking, friction, bond, or a combination of these three (EUgehausen et al. 2006), rather than use of an element such as a plate, a key, or a peg. Mechanical locking can be obtained, for instance, by undercut, namely, shaping the end part of the hole and introducing an anchor with an end shape so as to result larger than the rest of the shaft. Friction systems, instead, consist of torsion or displacement-... 

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