Structural bonding of heat-setting reinforced plastics for engineering

It has been found possible to use adhesives in place of other techniques for joining composite materials with a polyester matrix, reinforced with fibre-glass, which are used for making body parts for the transport industry. Research has therefore been centred round bonding advanced composite materials (with fibres arranged in specifically chosen directions) which, in the face of increasing demand for light-weight vehicles, may possibly be the answer to the problem of manufacturing highly stressed parts.

The fibres (glass or carbon) in these materials (polyester or epoxy matrix) are in one long piece and all lie in the same direction which is the one in which the maximum mechanical characteristics of the materials— close to if not greater than metal—are found.

Joining is done using structural adhesives calculated on the basis of: (a) test procedure, (b) surface treatment of bonding surfaces, (c) effect of ageing, and (d) fatigue test.