A research team from the Department of Physics, Chiang Mai University is adopting plasma technology, especially low-temperature plasma, by inducing  water resistance in textiles.

Plasma is an ion gas which is conductive by nature and reacts strongly to electric and magnetic fields. It is an efficient source of radiation and can be used in various kinds of applications, especially to improve the quality and performance of many products and processes.

Since plasma can improve the quality of products, the research team had the idea to use plasma as a coating on silk, a popular Thai textile, to give it waterproof properties.

Project leader Pradoong Suanpoot said that to coat plasma on silk, the team had to develop a plasma reactor, a plasma production source that will produce plasma for use when required.

Plasma is normally found in nature but to use plasma for specific requirements, production control and special sources of energy are needed.

Prodoong said that in the controlled environment of the sealed reactor chamber, the team could produce plasma by putting gas into the machine and then passing high-voltage electrical fields through it to make the gas split into ions and create plasma.

He said when plasma was coated on textiles, plasma ions would remain on the textile surface and give the treated surface a micro roughness. When water or liquid droplets come into contact with the surface, instead of soaking in and spreading, the process directs the liquid into precise, selected areas, even on a very small scale. This can render textiles waterproof.

Pradoong said the team had applied this method for use on Thai silk to improve the quality of the local product and this added more value. It would eventually help silk merchants sell their products at a higher price and with bigger margins.

Apart from Thai silk, he said the plasma treatment could also be applied for use on other kinds of textiles.

Meanwhile, the use of plasma to coat textiles offers a cleaner treatment method to the production process when compared to using chemical substances, as it does not release toxic compounds into the environment.

Pradoong said the team spent a year developing the plasma reactor, a key component for producing plasma for use in the experiments.

The team plans to further develop a complete version of the reactor prototype, which is expected to be ready next year.

The team also plans to use the new reactor to provide a plasma-coating service for local small and medium entrepreneurs and offer them the chance to use new technology that will improve their products.

"The reactor is an important part of the adoption of plasma technology. If we don't have this kind of machine, we can't produce plasma for practical use," he said.

Normally, a plasma reactor costs around Bt20 million to Bt40 million when imported. This limits the use of plasma technology, especially among local SMEs in Thailand.

Local development will help businesses use plasma services at a lower cost. The team also received Bt6 million as support from the National Research Council of Thailand to develop the reactor.

Textile treatment with plasma is just one of its ap plications. Other potential applications include plasma coating to produce high quality tools and construction materials, for superior surface finishing of plastics, plasma cleaning and etching to produce a new generation of chips for high-performance computers, and to make energy saving and environmentally friendly plasma.

Meanwhile, plasma treatment also helps increase the surface properties of advanced materials such as teflon.

Pongpen Sutharoj

The Nation