Fluorochemicals are organic compounds consisting of perfluorinated carbon chain. This is a film former that reduces the surface energy of a substrate, thereby providing one or more of the following properties:

• Oil Repellency


• Soil Resistance


• Water Repellency

  How do fluorocarbons affect the surface tension? Fluorocarbons form a thin film around the fiber, thus providing the fiber with a lower surface tension, since its surface tension is lower than most liquids.

Large contact angle	Small contact angle
Difficult to wet	Easy to wet
Low Critical Surface Tension (CST) of solid	High CST

The surface tension figures of various liquids and textiles is given here for a quick reference:

Since fluorocarbon particles are mainly cationic these are adsorbed by the anionic surface of the fiber. The heat evaporates water and causes the fluorochemical to flow. The final cure temperature results in continuous film formation around the fiber.

Fluorocarbons can be applied by any of the following ways:

• Padding: Most common method used in the fabric form due to high wet pick-up and complete fabric coverage.


• Kiss Coat: Again in fabric form. Low wet pick-up (10-30%) and is used for one-sided treatment of fabric. Poor repellency on the un-coated side.


• Spray: One-sided treatment of fabric. Lower wet pick-up than in padding (20-50%). Spray pressure is important.


• Foam: Low wet pick-up (10-15%) and one-sided treatment again. Foaming agent is needed (1-2%). Coverage could be uneven.


• Exhaust: Must be run after dyeing. Requires high affinity of fluorochemical for fiber. Usually for yarn packages, garments and knits.

• Bath concentration


• Drying and Curing


• Contaminants


• Silicones


• Sewing lubricants


• Rewetters


• Mechanical finishing


• Calendering


• Napping


• Application method


• Fabric construction