Oil repellent finishes

The oldest repellent finish is to repel water. The purpose of this finish is self evident. Drops of water should not spread on the surface of the textile and should not wet the fabric. The drops should stay on the surface and easily drip off. Similarly, oil repellent finishes should prevent oily fluids from wetting treated textiles. In a similar manner, soil-repellent finishes should protect textiles from both dry and wet soils. In all cases, the air permeability of the finished fabric should not be significantly reduced. Waterproofing treatments will not be covered in depth. A waterproof textile should withstand the hydrostatic pressure exerted by a column of water from at least aim height before the first drops of water penetrate through the fabric. In practice this is mostly achieved with coatings which have the disadvantages of stiff handle, lack of air and vapour permeability and consequently poor wear comfort. 

Friedrich S and Schindler W, Influence of water- and oil repellent finishing on the permeability to air of a woven cotton fabric , Melliand Textilberichte, 1990, 71, 211-213,E67-E68. 

Nuva. [Hoechst AG] Fluorine derivs. water and oil repellent finishing agents for textiles, leader. 

Velustrol KPA. [HoechstAG] Polyethylene emulsion softener for oil-repellent finishing on cotton fabrics. 

Ceria, A., Hauser, P, 2010. Atmospheric plasma treatment to improve durability of a water and oil repellent finishing for acrylic fabrics. Surf. Coat. Technol. 204, 1535-1541. 

Water and oil repellent finishes, normally perfluoroalkyl sulfonate (PFAS) and perfluorooctane sulfonate (PFOS), are not to be used, and their threshold limit is 1 pg/m each in the coated material whereas all other PFAS forms, the threshold limit is 20 pg/kg and MSDS is required to be supplied for verification. The test method is based on solvent extraction and GC-MS or HPLC-MS. For per fluoro carboxylic acids and salts (PFCA), the limiting value is 0.05 ppm or sum total is 0.1 ppm. 

Appretan EM, a polyvinyl acetate for stiffening finishes 2.5% Nuva CSF, a fluorocarbon for water and oil repellent finishing... 

Uses Water and oil repellent finishing of textiles from n. and natural fibers Properties YIsh. opalescent liq. 

Although the critical surface tension concept has been criticized for its empirical nature [27], critical surface tension data have been very useful in developing water- and oil-repellent finishes. One reason for this practical impact may be the similarity between the systems studied by Zisman and the surfaces of water-and oil-repellent finishes. 

Fluorochemicals used in water- and oil-repellent finishes have been monomeric or polymeric. The first fluorochemical repellents used commercially were monomeric. In analogy to repellents with a hydrocarbon hydrophobe (see Section 12.1), perfluoroalkanoic acids, and phosphate esters have been applied as chromium complexes [121-123], zirconium or titanium alkoxides or salts [124-126] or have been converted to quaternary amines [127,128] ... 

Figure 3. A drop of water, including cellnlolytic enzymes, on the surface of cotton fabric coated with water and oil repellent finish.

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