Surface Modification of Fabrics Under Plasma Treatment

Plasma Treatment on Fabric:

The plasma-induced surface modification of textile substrates has gained increasing importance over the last few years. Probably the most advantage behind this renewed interest in plasma technology is the restriction of the concentration of AOX compounds in the discharged effluents to 0.5 mg/1. The other reason for this interest is the intriguing possibility of modifying properties leading to better performance. The range of applications is diverse and modifications of surface of various materials like cotton, wool, silk, polyester have been reported.

Plasma Treatment on Fabric

Plasma treatment generally takes place in dry conditions, thus the fibers are not swollen. The changes in properties induced by plasma treatment are therefore restricted to the surface and any damage to the interior of the fiber is very unlikely.

The physico-chemical nature of the modified fibre surface has a tremendous influence on the following important phenomenon:

1. Static electricity build up and dissipation.
2. Moisture transport and comfort.
3. Oily stain adsorption and release in detergent solution.
4. Soil deposition, release and redeposition in detergent solutions.
5. Wettability and adhesion.
6. Scourability and bleachability of textiles.
7. Wettability and dyeability

Form the physical point of view, roughening of fibre surface as seen by atomic force microscopy is responsible for changes in the coefficient of friction, top cohesion, spinnability, yam strength, etc., as well as for increase in felting resistance of wool. From the chemical point of view, the oxidation of the fibre surface and interaction with polymeric materials are the main factors responsible for improvements in various properties of plasma treated materials.

Effect on Wool:
Wool is a protein fiber. It is obtained from the fleece of the sheep or lamb or hair of the Angora or Cashmere goat. The effects of a plasma treatment on wool has revolutionary changed such as anti-felting effect, degreasing, improved dyestuff absorption and increase in wetting properties. We have published a informative article on “Effects of Plasma Treatment on Wool”. You can read also.

Other changes in wool properties are summerised below :

• Plasma treatment increases the fibre/fibre friction of wool.
• Plasma treatment does not change the strength and elongation;
• The fatty matter content in wool is reduced by about one-third due to plasma treatment.
• The water content of the wool top is reduced by about 3% due to plasma treatment.
• There is changes in spinning behaviour of plasma treated wool

Effect on Other Fibers:
Plasma may be used for removing the contaminants, finishing and sizing agents from the fabric. Desizing of polyester fabric that used polyvinyl alcohol as the sizing agent can be removed by plasma treatment.

The efficiency of scouring, mercerizing etc. depends on the penetration of water into the fibre and thus its wettability The wettability of cotton and silk is increased a few fold due to its pre-treatment by N 2 plasma. In case of polyester fabrics also the wettability increases significantly.

The hydrophobic effect on a woven cotton fabric can be obtained by surface treatment. Plasma treatment with acid as a component of original gas will result in a hydrophilic surface.

Polyester fibres can be effectively modified by low pressure plasma treatment.

Soiling of fabrics is another important aspect. Treatment of polyester with air plasma considerably decreases the soiling. During plasma treatment fabrics get negatively charged. The soils are also generally negatively charged and therefore there is increased repellency.

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