Application of Plasma Technology in Textiles

Application of Plasma Technology in Textile
  • Desizing of cotton fabrics.
  • Hydrophobic enhancement of water and oil-repellent textiles
  • Anti-felting/shrink-resistance of woollen fabrics.
  • Hydrophilic enhancement for improving wetting and dyeing.
  • Hydrophilic enhancement for improving adhesive bonding
  • Removing the surface hairiness in yarn.
  • Scouring of cotton, viscose, polyester and nylon fabrics.
  • Anti-bacterial fabrics by deposition of silver particles in the presence of plasma.
  • Room-temperature sterilization of medical textiles.
Plasma technology can be used to remove PVA sizing material from cotton fibers. In conventional desizing process we use chemicals and hot water to remove size. But desizing with plasma technology we can use either O2/He plasma or Air/He plasma.

Firstly the treatment breaks down the chains of PVA making them smaller and more soluble. X-ray photoelectron microscopy results reveal that plasma treatment introduces oxygen and nitrogen groups on the surface of PVA which owing to greater polarity increase the solubility of PVA.

Of the two gas mixtures that were studied, the results also indicate that O2/He plasma has a greater effect on PVA surface chemical changes than Air/He plasma.

Water Repellent Finishing on Cotton
The literature on water-repellency and waterproofing is frequently confusing, because the repellency effect observed depends upon the test method and the test conditions used.
  • The term ‘water-repellent’ is actually a relative term because there is always some attraction between a liquid and a solid with which the liquid is in contact.
  • The term ‘waterproof’ is normally taken to represent the conditions where a textile material (treated or untreated) can prevent the absorption of water and also the penetration of water into its structure.
Felting of Wool
  • The process of felting involves relative movement of the fibers which may be caused either by mechanical rubbing or by a series of compression-extension operation.
  • Under the influence of these intermittent forces of squeezing, twisting etc., the wet fibers migrate in a preferential root ward direction because of the DFE, and at the same time they tend to curve, loop and entangle with each other. This is the reason of Felting of Wool.
  • This process is irreversible. Because of the anchoring effects of the entangling and the differential frictional properties of fibres.
  • Crimpiness, flexibility and hygroscopic quality combined with delicacy of fibers, are the most important factors in felting.
  • Felting is a complex process, and the felting capacity depends not only on the inherent properties of wool, but also on the conditions of the felting process.
Anti Felting Treatment on Wool by Plasma Technology
Plasma treatment of wool fibers has shown to reduce this curling effect by etching off the exocuticle that contains the disulfide linkages which increase cross linking and contribute towards shrinkage. This procedure also enhances wetability by etching off the hydrophobic epicuticle and introducing surface polar groups.The increase in surface area of the fiber, recorded with atomic force microscopy, is increased from 0.1m2/g to 0.35m2/g. These physio chemical changes degrease the felting/shrinkage behavior of wool from more than 0.2g/cm3 to less than 0.1g/cm3. 
Wool fiber
For this process we may use oxygen, nitrogen or mix. Of these gases.

Several studies have shown that dye ability or printability of textiles can be markedly improved by plasma treatments. This effect can be obtained on both synthetic and natural fibres. Capillarity improvement, enhancement of surface area, reduction of external crystallinity, creation of reactive sites on the fibres and many other actions can contribute to the final effect depending on the operative conditions. Also production of colors on fibres exploiting diffraction effects has been attempted.
E.g.. The dye exhaustion rate of plasma treated wool has been shown to increase by nearly 50%. It has been shown that O2 plasma treatment increases the wetability of wool fabric thus leading to a dramatic increase in its wicking properties. Also the disulphide linkages in the exocuticle layer oxidize to form sulphonate groups (which is act as active sites for reactive dyes)which also add to the wetability . The etching of the hydrophobic epicuticle and increase in surface area also contributes towards the improvement in the ability of the fibers to wet more easily.

  • The graph below shows that plasma treated wool can achieve 90% exhaustion in 30 minutes as compared to 60 minutes for untreated samples.
  • When wool is dyed with reactive dyes maximum exhaustion is achieved A possible explanation to this behavior of reactive dyes is due to the increase in sulphonate groups on the fiber surfaces.


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