A range of commercially available adhesives have been screened for bonding self-reinforced polypropylene joints using a single lap joint and tested in accordance with BS5350. Adhesives trialled were:

   2-part acrylic (low temperature applications)
   Hot-melt Films
   Cyanoacrylate & primer
   1-part PU & primer & treatment (higher temperature applications)
   2-part PU & primer & treatment (higher temperature applications)
   Hot melt PP–wood

Tests were conducted at 17 degrees c (ambient), 105 degrees c and 120 degrees c.

Joints bonded using the 2-part acrylic adhesive, which required no special surface preparation, had the highest shear strength at ambient temperature and the specimens failed in the self-reinforced polypropylene substrate, indicating that the shear strength of this adhesive exceeds that of the self-reinforced polypropylene.

The 1-part and 2-part polyurethane adhesives exhibited better resistance to elevated temperature, whilst the hot-melt film performed well at all temperatures and is suitable for bonding large areas.