Plasma technology has been widely used in various forms in the fields of functional materials, new materials synthesis, metal cutting, ozone generation, air purification, food, environmental, chemical, mechanical industries, etc. In particular, surface treatment of objects based on plasma has been studied by many researchers because it can improve several properties of the surface and broaden its application.
Dielectric barrier discharge is a very effective non-equilibrium plasma generation method that prevents the transition into spark and arc discharge that occurs in the discharge gap by inserting dielectric into the discharge space. Corona discharge is also an effective method of non-equilibrium plasma generation at atmospheric pressure. However, its discharge area is small and the power density is not high. Hence, if corona discharge and dielectric barrier discharge are properly combined, the discharge is more uniform and stable due to the corona effect at the corona electrode in the discharge space and high power density atmospheric pressure discharge can be realized.
The discharge formed by high frequency and high pressure after the insertion of dielectric into the corona discharge space is called dielectric barrier corona discharge (DBCD). Treatment of the surface of resin or cloth by DBCD can improve the surface properties by changing the adhesion, resistance, dyeing, painting, gloss, wear resistance, hydrophobicity, etc.
Kim Jin Hyok, a researcher at the Institute of Nano Science and Technology, has generated dielectric barrier corona discharge using quartz glass as dielectric in the atmosphere, treated the surface of Tetron fabric by passing it through the discharge space, and considered the change of its characteristics. At high frequency, high pressure power supply of 15 kHz and 18kV, he treated the Tetron fabric with varying discharge power, treatment speed and number of treatments, and measured the change of water penetration time to compare its surface characteristics.
As a result, he has found the following.
First, the higher the discharge power is, the shorter the water penetration time gets and the better the hydrophobicity becomes. When the slower the treatment speed is, i.e., the longer the treatment time for the unit area of the Tetron fabric is, the higher the treatment efficiency is, which leads to the shorter water penetration time. The more the number of treatment is, the better the surface properties become and the shorter the water penetration time gets.
From these characteristics, he determined the optimal surface treatment parameters by the Taguchi method. They are 900W of discharge power, 7cm/s of treatment migration rate and 4 rounds of treatment. Under these conditions, water penetration time is 9.2s.
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