ATMOSPHERIC-PRESSURE PLASMA TREATMENT OF POLYETHYLENE VIA A PULSE DIELECTRIC BARRIER DISCHARGE - COMPARISON USING VARIOUS GAS COMPOSITIONS VERSUS CORONA DISCHARGE IN AIR

Modification of polyolefin surfaces is often necessary to achieve impr oved printability, lamination, etc. Although corona discharge and flam e treatments can produce the higher surface energy needed for these ap plications, the properties of the resulting surfaces are not always op timal. Atmospheric pressure plasma is a surface modification technique that is similar to corona discharge treatment, but with more control, greater uniformity, and higher efficiency. Using an atmospheric press ure plasma unit with a dielectric barrier discharge generated using an asymmetric pulse voltage, the effects of different gases, powers, and linespeeds on polyethylene surface treatment were studied. Our result s show that atmospheric pressure plasma can be used to achieve higher long-term wettability, higher surface oxygen and nitrogen, and a great er range of surface chemistries with better robustness versus standard corona treatment. Atomic force microscopy results suggest significant differences in the mechanism of surface functionalization versus etch ing and ablation depending on the gases used. (C) 1999 John Wiley & So ns, Inc.