Surface modification of fabrics using a one-atmosphere glow discharge plasma to improve fabric wettability

In industrial applications, a steady-state glow discharge capable of operating at one atmosphere would allow many plasma-related surface modification processes to be done on the production line, rather than in expensive vacuum systems that force batch processing. In this paper, we report some encouraging results from the plasma surface treatment of polypropylene meltblown nonwovens in the UTK one-atmosphere glow discharge plasma reactor. This reactor generates a large volume (up to 2.4 liters), low power (less than 150 watts), uniform glow discharge plasma in a parallel plate configuration with oval electrodes of 213 cm(2) face area, the lower electrode being covered with a 3.2 mm thick insulating Pyrex surface. The plates are set up in an enclosed box that makes it possible to control the working gas used, and the spacing between the plates can be varied. This reactor is energized by a custom-made high impedance kilohertz power supply capable of supplying up to 5 kilowatts of kilohertz power at RMS voltages up to 10 kV, and over a frequency range from 1 to 100 kHz. Exposing a wide variety of polymer fabrics reveals that the wettability, wickability, printability, and surface contact angle of the materials are significantly changed in a direction that may lead to new uses for these materials.