The effect of technological and structural factors on the strength of polyethylene adhesive joints

Abstract

This paper discusses the issues concerning the strength of PE–HD 500 polyethylene adhesive joints depending on the applied variable structural and technological factors. The variable structural factor was joint geometry: the samples were single-lap joints and butt adhesive joints. As far as the technological factors are concerned, two types of cyanoacrylate adhesives were used (Loctite 401 and Loctite 406), different surface preparation methods were employed (with and without the application of a primer) and different primer-application techniques were used (the primer was applied to one or both adherend surfaces). The primer was selected with respect to the adherend and adhesive types. The samples of the produced adhesive joints were subjected to dimensional analysis followed by destructive testing. The strength tests were performed on the Zwick Roell Z150 testing machine in accordance with the DIN EN 1465 standard. Following the destructive tests, the adhesive joints were examined with respect to failure patterns based on visual valuation and the standard PN-EN ISO 10365. The statistical analysis was performed by the F-Snedecor and T-Student tests, the Cochrane-Cox test as well as relevant statistical models, taking into account the first error type of α = 0.05. The results demonstrate that the adhesive joint strength of elements made of polyethylene is affected by both surface preparation method (including the use of the primer) and the type of adhesive used. It is observed that the strength of adhesive joints increases with increasing the amount of the primer.