Lubricants and cohesive agents

Waxes are a group of organic compounds consisting mainly of heat-sensitive hydrocarbons which are insoluble in water but soluble in most organic solvents and, most of them, free from glyceride. Sources of waxes can be animal, vegetable, mineral, synthetic and petroleum. The waxes used for fibre finishing are 

One chemical test that is useful for textile wet processes may be the spot test. By using hydroxamic acid, waxes and fatty oils can be distinguished from their mineral counterparts. In a small crucible, one drop of a saturated ethanol solution of hydroxamic acid is mixed with one drop of an ethanol solution of the sample and one drop of an ethanol solution of KOH. The mixture is heated to bubbling (evaporation) and then allowed to cool and is acidified with HCl. A drop of FeCl, is added to the acidified sample. A violet colour confirms the existence of waxes and fatty oils. Carboxylates may also give a positive result. If the saponification number of waxes needs to be known, ASTM D1387 can be used. ASTM D1386 can be used to determine the acid number of waxes.  

Oils and greases belong to the same type of organic compounds as waxes but have lower molecular weights. Oils have a lower viscosity and are used at lower temperature than greases. 

The total content of oils, fats and waxes on fabrics can be extracted with 1,1,1-trichloroethane using the Soxhlet extractor. By comparing the fabric weight before and after extraction, the weight percentage of oils, fats and waxes can be easily calculated. It was reported that supercritical CO can be used instead of the toxic organic solvent to extract the commercial finishes from polyester, nylon and polypropylene fibres.  

Many synthetic compounds can be used as lubricants and cohesive agents. In the 

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