Water repellency
Water repellency properties of fabric represent fabric behaviour towards water or up to which level fabric can impermeable towards the flow of water.
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| Water repellent fabric |
Waterproof, showerproof, and water-repellant are the types of this fabric properties.
Water-repellent fabrics are generally outerwear such as anoraks, cagoules and raincoats and also industrial fabrics such as tents and tarpaulins.
Widely waterproof and showerproof are two main categories of resistance to water.
Penetration of water in fabric samples is recognised based on the treatment that has been used in fabric production or in the processing unit.
Waterproof fabric is considered which is a barrier to pass the water by using coated or impregnated to a continuous form of another layer.
For coating generally, rubber, polyurethane, PVC or wax coatings are used.
Generally in fabrics, the gaps between the yarns, are filled in by the coating which gives rise to two main drawbacks. One is the fabric will no longer allow water vapour to pass through it, making it uncomfortable to wear when sweating. Another is the binding together of the yarns by the coating reduces the ability of the fabric to shear and thus mould to the body contours.
A showerproof fabric is considered which is treated in the process to delay the absorption and penetration of water.
Showerproof fabrics are obtained by coating them with a thin film of a hydrophobic compound such as silicone.
This hydrophobic film covers the surface of the individual fibres making them water-repellent.
When a fabric has been treated by a drop of water on the surface, it does not spread.
(However, whenever this coating or film is applied on fabric by process, it is necessary to leave minor gaps in the fabric weave, these untouched gaps keeping it quite permeable to air and water vapour.)
The process also leaves the handle of the fabric largely unaffected unlike fabrics with a waterproof coating.
Water can penetrate the fabric if it strikes it with sufficient force as in heavy rain or alternatively the flexing of the fabric during wear can cause the gaps in the weave to open and close so allowing the water to penetrate.
A showerproof fabric can also be produced by a correct choice of yarn and fabric construction to give a very tight weave that physically keeps the water out.
I.e. - the gabardine construction used in coats.
Questions -
- What is water repellence?
- What is the water-repellent fabric?
- How water repellent fabrics made?
- Where water repellent fabric used? OR what is the application of water-repellent fabrics?
References
Booth, J. E. :. (n.d.). Principles of textile testing an introduction to physical methods of testing textile fibres, yarns, and fabrics. London: National Trade Press Ltd,1961. from https://www.abebooks.co.uk/Principles-Textile-Testing-Introduction-Physical-Methods/19989810376/bd
Cenote, M. (2015). Google Books. In The SAGE Guide to Key Issues in Mass Media Ethics and Law (pp. 847–858). SAGE Publications, Inc.
Ferreiro López-Riobóo, J. I. (2015). Long-term (2001–2012) study of a proficiency testing scheme for textiles. Accreditation and Quality Assurance, 20(4), 239–245. https://doi.org/10.1007/s00769-015-1128-1
Babu, S. (n.d.). Textile Adviser. Textileadvisor.com. from https://www.textileadvisor.com/2020/05/testing-of-air-permeability-of-fabric.html
Ding, X. (2008). Fabric permeability testing. In J. Hu (Ed.), Fabric Testing (pp. 189–227). Elsevier.
Hakoo, A. (2019, April 29). Importance of Air Permeability/Fabric porous structure in the production of technical textile fabrics. Textile School. https://www.textileschool.com/5194/importance-of-air-permeability-fabric-porous-structure-in-production-of-technical-textile-fabrics/
- Further reading
- Part-1 Water repellency introduction
- Part-2 Water repellency measurement - spray rating
- Part-3 Water repellency measurement- bundesmann water test
- Part-4 Water repellency measurement- WIRA shower test
- Part-5 Water repellency measurement- Fabric hydrostatic head tester
Writer - DSPAT Team
