Investigation of the effect of environment friendly atmospheric pressure cold plasma application on bond strength of pom and pp materials

Abstract

Purpose: Cold atmospheric pressure plasma (CAPP) processes were performed on polypropylene (PP) and polyoxymethylene (POM) polymers with different process speed and distance. Two different types of adhesives applied on these polymers and characterization methods were carried. It was aimed to investigate the effect of CAPP process on surface free energy and bonding strength.Theory and Methods:For CAPP treatment three different plasma process speed and two different distances were carried out on PP and POM materials. Polymers were treated at 0.5, 1, 1.5 cm/s process speed, 1-1.5 mm process distance. Piezobrush (R) PZ2 model atmospheric pressure plasma device, which uses air as the process gas, was used for surface treatments and a device was made by us to control the plasma processing speed. Water contact angle measurements, surface free energy measurement with special inks and tensile test carried out for characterization.Results:It was observed that the tensile strengths of adhesives increase due to increased surface free energy after CAPP process. Varying increases in adhesion strength were observed for each polymer-adhesive pairs after plasma treatments at different speeds and distances. After the CAPP treatment, the water contact angle measurements show that polymer surfaces changed to hydrophilic.Conclusion:The results show that atmospheric pressure plasma treatment is an alternative to other surface energy enhancement methods due to its environmental friendliness, ease of operation and low operating costs. However, it is necessary to continue rapidly in CAPP research for better results and popularization of use in practical applications.