Different ways that low energy surfaces
mechanical incorporation of the water-repellent products in or wateron the fibre and fabric surface, in the fibre pores and in the spacing between the fibres and the yarns. Examples ： paraffin emulsions. chemical reaction of the repellent material with the fibre surface. Examples ： fatty acid resins. formation of a repellent film on the fibre surface. Examples ： silicone and fluorocarbon products. use special fabric constructions like stretched polytetrafluoroethylene films (Goretex), films of hydrophilic polyester (Sympatex) and microporous coatings (hydrophilic modified polyurethanes).
6.3 Repellent chemistry
6.3.1 Paraffin repellents
6.3.2 Stearic acid–melamine acid– repellents
6.3.3 Silicone water repellents
6.3.4 Fluorocarbon-based Fluorocarbonrepellents
6 Repellent finishes
outline
6.1 Introduction 6.2 Mechanisms of repellency 6.3 Repellent chemistry 6.4 Evaluation of textiles treated with repellent finishes 6.5 Troubleshooting for repellent finishes and particularities
6.1 Introduction
6.2 ms of repellency
Repellent finishes achieve their properties by reducing the free energy at fibre surfaces.
If the adhesive interactions between a fibre and a drop of liquid placed on the fibre are greater than the internal cohesive interactions within the liquid, the drop will spread. If the adhesive interactions between the fibre and the liquid are less than the internal cohesive interactions within the liquid, the drop will not spread.