Method of treating inner surface of plastic tube with plasma.

摘要

In plasma-treating the inner surface of a plastic tube, the invention provides a treating method which ensures stable treatment under readily operative conditions. The present invention relates to a method comprising the steps of placing a plastic tube inside an electrically insulating tube wherein the difference between the inner diameter of the insulating tube and the outer diameter of the plastic tube is less than 2 mm, letting a gas into the plastic tube, keeping the inner pressures of both tubes at a reduced pressure, applying a high voltage across electrodes disposed outside the electrically insulating tube to initiate and sustain discharge inside the plastic tube and thus plasma-treating the inner surface of the plastic tube.