Effects of electrode types in corona discharge treatment on adhesive strength of low density polyethylene sheet

摘要

The surface modification of low density polyethylene (LDPE) sheet was carried out by corona discharge treatment using four different electrodes in shape, i.e., rod, groove, knife - like, and hemicylic electrodes. The adhesive strength was determined for the laminated film composed of LDPE with polyethylene-terephthalate (PET). The adhesive strength became strong when polymers were treated knife-like and hemicylic electrodes. It was also confirmed by XPS analysis that almost complete cohesive failure occurred in peeling test. Homogeneity of treatment was evaluated through peeled curve and the photograph in corona discharge. The treatment with hemicylic electrode led to be more homogeneous on oxygen content of LDPE surface than that with the other electrodes. The adhesive strength reached over 900 N/m when both of LDPE and PET were treated.