8 октября, 2015 
Pokraskin In this section, a guide is given to indicate the performance of several different adhesives for a selection of six thermoset plastics.
The bulk of this information was taken from ‘The Loctite Design Guide for Bonding Plastics’ issued by Henkel Ltd [3] and for more detailed information the reader should refer to this guide.
An adhesive cannot be selected solely on the basis of bond strength information as other factors such as cure speed, environmental resistance and dispensing method will all influence the final choice. The values given for the shear strength are given to provide a general idea of how each of the nine adhesives performed on the particular material. Different performances will be achieved depending on the fillers, lubricants, colourants and anti-static additives within the grade of plastic.
The nine different adhesives selected for these charts were as follows:
• Three cyanoacrylates (standard ethyl, toughened grade and ethyl + primer),
• Two acrylics (a standard methylmethacrylate (MMA) and a polyolefin bonder),
• Two epoxies (a 5-minute epoxy and a longer cure grade),
• One room temperature vulcanised silicone (alkoxy cure), and
• One ultraviolet (UV) acrylic (cure at 420 nm).
A brief description of each adhesive is given together with a few general comments on the overall performance of the adhesives.
The alkoxy silicone often showed a strength of 1.4 N/mm2 for many of the plastics tested but in this case the adhesive has failed cohesively. A silicone adhesive is often
used where sealing might be the main priority of the adhesive rather than structural strength.
In the case of UV adhesives where the material was invariably opaque, the plastic was bonded to a polycarbonate test specimen.
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