11 октября, 2015 
Pokraskin Polyurethanes can have the physical structure of a solid casting, a flexible elastomer or soft or rigid foams. It can be either a thermoplastic or more usually it is a thermoset material. The isocyanates in polyurethanes often result in health and safety implications during cure or processing and so must be carefully controlled.
Polyurethane plastics can sometimes be difficult to bond and some surface treatment may be necessary. With the wide variety of grades and end-products available, it is
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difficult to give specific data. The data given in Table 3.5 is for guidelines only. Some polyurethanes can be stress cracked by cyanoacrylate adhesives and by some solvent — based activators or primers.
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Table 3.5 Adhesive shear strengths (polyurethanes)
Notes: All shear strengths are given as guidelines only and may vary considerably depending on grade of plastic, fillers, surface finish, etc. |
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