Troubleshooting for repellent finishes and particularities

Conditions for high repellency of finished fabrics inclnde a close-packed textile structnre with small inter-yam spaces (therefore better woven than knitted) with fine yams (preferably microfibres or microfilaments) and a uniform distribution of the repellent finish. This last condition is enhanced by the removal of protmding surface fibres by singeing or shearing. 

Any residnal sizing agents or surfactants present on the fabric can defeat the repellency properties. All fabrics destined for repellent finishes should be well prepared prior to finishing. Non-rewetting, thermally degradable or volatile surfactants such as isopropanol should be used in the repellent finish bath to maximise the final properties. 

Repellent finishes are usually compatible with easy-care and durable press finishes and many softeners. However, most silicone products interfere with the oil repellency of fluorocarbon finishes and should generally be avoided in an oil-repellent formulation. This is a remarkable contrast to the incorporation of silicone segments in the backbone chain of fluoropolymers, which generates a special soft handle. 

The combination of EC and antistatic finishes, achieved with selected products is important for synthetic microfibre textiles. Other common finish combinations include hand builders, flame retardant and antimicrobial agents, which generate valuable and useful multifunctional finishes. 

FC finishes alone do not sufficiently prevent coffee, tea and other foodstuffs from dyeing nylon and wool carpets with coloured spots, especially when these liquids are not quickly removed. Stain blocking for these carpets is achieved by the combination of FC products with syntans. The latter are also used for wet fasmess improvement of acid dyed nylon (see Chapter 13). Stain repellency is promoted by hydrophobic finishes, mostly fluorocarbons, but with decreasing costs also by 

---