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The effect of forced air-plasma pre-treatment, Lectro-treatTM, on polypropylene has been investigated using X-ray photoelectron spectroscopy (XPS), angle-resolved XPS (AR-XPS), and atomic force microscopy (AFM). The pre-treatment process is found to induce both surface chemistry changes and topographical changes. The parameters of the pre-treatment process can be optimised from these observations. The Lectro-treat pre-treatment process has been used for adhesive bonding of a demonstrator component: a bumper assembly. The adhesively bonded bumpers performed successfully in standard automotive tests. [ABSTRACT FROM AUTHOR]

Five commercial structural adhesives were tested using the thick adherend shear test (TAST). These adhesives have mechanical properties ranging from those of high-strength, heat-cured epoxies to ductile, acrylic-based materials. Consideration was given to the adherend selection and dimensions to approach a uniform shear stress-strain in the bonded area, so that the test could be used with both stiff and flexible adhesives. Comparison of the TAST results was also made with those obtained using the butt torsion test. The TAST extensometry has been shown to be suitable for measuring the shear strain properties of the adhesives tested without modification. From the shear behavior of the five adhesives measured using the TAST method, and from the results presented in this paper, it can be seen that the TAST method is repeatable and reproducible for a wide range of adhesive types and adhesive properties. From these results, it is possible to generate comprehensive adhesive shear data. Also, the curves from the butt torsion test and the TAST were found to be consistent and give the same behavior of the adhesives tested. [ABSTRACT FROM AUTHOR]