Fur Finishing

Naturally white, but slightly yellowed fur skins from sheep and lambs are reduction bleached, most commonly with dithionite or/and in combination with hydrogen peroxide in a weakly alkaline medium. A true bleach in the sense of destroying the natural pigments in the hair can only be achieved by means of oxidation with, e g., hydrogen peroxide, catalyzed by iron(n) salts. This exothermic process is very difficult to control and must be monitored carefully. In addition, the skin must not be chrome tanned, as this could cause serious damage. 

Normally, on wild or farmed skins, the hairs are dyed only if unavoidable. The leather portion, known as suede , is seldom dyed. In contrast, sheep- and lambskins are colored according to fashion trends. They are called double-face and are dyed tone-in-tone , with the same shade for suede and wool. Two-tone dyeing is also common. It is frequently named bicoloT because suede and hair have different colors. For example, black-dyed hair looks much more exquisite if the suede is dyed blue. Dyed suede with white wool can be found, and conversely undyed suede with dyed hair, too. 

Fur dyes are applied in a bath of color, by rolling the dye onto the fur, stroking it on with a feather, or simply by touching up the tips of the guard hair. For batch production, the vessels most frequently used for wet treatment are paddles in which the fur skins float in long (dilute) liquors. 

color effects for double face such as snow top , in which the dyed hair is brushed with special reductive chemicals to bleach it, are in fashion. Finally, it is also usual to print some lamb- or woolskins to imitate more valuable furs. Imitations are produced not only with sheep or lambskin but with rabbitskin, too. These various starting materials may be stencilled to resemble leopard or other spotted furs. 

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HartoweL [Hart Chem. Ltd. Wetting agent fur finishing frxmulations in textiles, pulp and psq)er processing. 

The smoothing or finishing of the surface was fur- merly accomplished by placing the sheets of paper between glazed pasteboards. The boarde, intermixed at intervals with heated iron plates, wore then put Into a press and subjected to heavy pressure—a process, which is well known by the name of hot-pressing. It was very beneficial to the paper, as it took out any superfluous moisture, and made it handle firmly. -... 

The sulphate of soda is heated in the salt oako fur-nace until it assumes a reddish-yellow tint, when it is raked out through tho doorway, G, and is considered finished. 

Repeated tumbling in sawdust removes unwanted residue. A final glazing, ironing, or spraying with a chemical and air blowing puts a sheen on the finished fur. The wool of sheep and other skins with dull and crimped hair can be stretched and made more lustrous by ironing on a special machine. It is brushed with water and some acetic acid and alcohol then ironed for a short time at ca. 200 °C. 

Before dyeing with oxidation dyes, the furs are treated with the appropriate killing agents and then mordanted with metal salts. Iron, chromium, and copper salts, alone or in combination, are used for mordanting, and the uptake process requires several hours. Adjustment of the pH is effected with formic, acetic, or tartaric acid. The final dyeing process is carried out in paddles with the precursors and hydrogen peroxide until the actual dye lake is developed and adsorbed within the hair fiber. It takes quite a few hours at room temperature until the dyeing process is finished. 

The change in policy by Courtaulds was fortunate for Vera Isabella Furness." Born on 2 June 1921, Furness attended a teacher training college and became a secondary school teacher. While teaching full-time, she studied for a B.Sc. (London) in chemistry through the Birmingham Central Technical College (later University of Aston), which she completed in 1946. Hired as a development chemist at BX Plastics, she undertook research towards an M.Sc., which she finished in 1948, followed by a Ph.D. in 1952. 

The most important market for insect resist finishes is the carpet industry. More than two-thirds of these finishes are nsed with floor coverings and wall hangings. Other significant markets include home furnishing and upholstery fabrics, blankets, uniforms, apparel and furs. 

Chemical cleaning of wool textiles as smaller carpets, wall hangings, upholstery fabrics, furs or uniforms can easily be combined with the application of insect resist finishes. Dip and cautious spray application is used for the protection of wool and silk textile exhibits in museums. 

Defoamers are used in fibre finishes in order to inhibit the formation of foam during the manufacturing and application of the finishes. Silicones and fluorochemicals are outstanding defoamers. They have very low surface tension and limited solubility in many organic compounds. They can quickly reduce the local surface tension of bubbles to create an imbalance of surface tension which leads to the easy rupture of bubbles. Silicones can be analysed using FUR. The analysis of fluorochemicals is difficult because fluorochemicals, especially perfluoro compounds, are resistant to many reagents. One microdetermination of fluorine by alkali fusion in a metal bomb was reported. Since it is too complicated and specialised apparatuses are used, this method is not introduced here. 

Organizations such as the Association of American Textile Chemists and Colorists (AATCC) and the American Society for Testing and Materials (ASTM) in the USA, the British Standards Institute in the United Kingdom, the Deutsches Institut fur Normung (DIN) in Germany and the International Organization for Standardization (ISO) headquartered in Switzerland publish test methods that can be used to evaluate the performance of chemical finishes. 

Astacin . [BASF AG] Finishes, softeners for leather and fur industry. 

Persistol. (BASF AG] Hydrophobic and oletphoi agents for textile finishing, furs. 

To provide the finishing touches on the production of leather and fur products ... 

Mikolajczyk, W., Wawro, D., and Struszczyk, H., Fibres Text. East. Fur., 1998, 6(2), 53. Struszczyk, H. et al., Polish Patent 163049, to Instytut Wlokien Chemicznych, Lodz, Poland. Starostka, P. et al., Polish Patent 165916 Bl, to Instytut Wlokien Chemicznych, Lodz, Poland. Eklund, V. et al.. Finish Patent 67562, to Neste Oy. 

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