High-efficiency plasma treatment of paper

A method for treating paper material with a plasma comprising the steps of:

• (a) supplying a treatment gas to an enclosure;
• (b) driving a treatment electrode or a counter electrode with an oscillating high voltage at a frequency less than about 2 MHz and greater than 1/tc where tc is the charging time of a web surface exposed to a rms ion current in the plasma generated in the enclosure with the treatment electrode and the counter electrode, the treatment electrode having a surface area in a treatment zone which is not greater than a surface area of the counter electrode;
• (c) conveying a paper web through the treatment zone between the plasma and the treatment electrode;
• and
• (d) incorporating the treatment gas in the treatment zone into a surface of the paper web in the form of oxygen containing reactive surface groups or nitrogen containing reactive surface groups.

A method for treating paper materials with a plasma comprising the steps of:

• (a) supplying a treatment gas to a plasma zone;
• (b) driving a treatment electrode or a counter electrode with an oscillating high voltage at a frequency less than about 2 MHz and greater than 1/tc where tc is the charging time of a web surface exposed to a rms ion current in the plasma generated in the plasma zone with the treatment electrode and the counter electrode, the treatment electrode having a surface area in a treatment zone which is not greater than a surface area of the counter electrode;
• (c) generating the plasma in the plasma zone with the treatment electrode and the counter electrode;
• and
• (d) conveying a paper web through the treatment zone between the plasma and the treatment electrode thereby removing or cross-linking aliphatic carbon species from the surface of the paper web and forming reactive surface groups on the surface of the paper web.