The effect of degreasing on adhesive joint strength

The paper investigates the effects of degreasing, surface preparation methods in adhesive bonding and con adhesive joint strength. Five types of degreasing agents were used in the study: acetone, extraction naphtha, Ultramyt, Wiko and Loctite 7061. The degreasing operation was performed by three methods: rubbing, spraying and immersion. Strength tests were performed on single-lap adhesive joints of hot-dip galvanized metal sheets made with Loctite 9466 adhesive according to the above variants of surface preparation. The experimental results demonstrate that adhesive joint strength is significantly affected by the applied degreasing agent. Moreover, the method of application of the degreasing agent is crucial, too. The results of strength testing reveal that the most effective degreasing method for hot-dip galvanized metal sheet adhesive joints is spraying using extraction naphtha. Thereby, degreased samples have the highest immediate strength and shear strength. The use of extraction naphtha is also effective in combination with degreasing by rubbing; however, it is not effective when used in combination with immersion, as reflected in the lowest strength results.