Consistency, of lubricating

A typical spin-finish concentrate would consist of lubricant (usually blended), 75-85%, antistat, 5-10%, and additives (antioxidants), 5-10%. Formulations of textile machine lubricants based on water-soluble PAGs combine gear lubricity with ease of removal from fibres during processing. 

Lubricating greases [24] consist of lubricating oil in which a thickener is dispersed as a microscopic second phase. One of the more important physical aspects of the greases is the stability of the grease structure as provided by the oil thickener interaction. Two tests that... 

Apparatus for measuring the consistency of lubricating grease, asphalt and rubbers. A standard cone (for grease) or needle (for wax, rubber or asphalt) is lowered onto a test sample, under prescribed conditions, and the depth of penetration is measured. 

For rigid PVC the extract will be much smaller, typically 1-5%, and will consist of lubricants such as long-chain aliphatic esters, e.g. glyceryl mono-ricinoleate, long-chain aliphatic acids and alcohols, and hydrocarbon and amide waxes. Metal-based stabilisers such as metal carboxylates or organo-tin compounds may be present. Also present may be nonmetal stabilisers such as ESBO, organic phosphites, bisphenol A, and polyols such as trimethylolpro-pane or pentaerythritol. 

The base lubricant is usually a petroleum oil while the thickener usually consists of a soap or soap mixture. In addition they may contain small amounts of free alkali, free fatty acid, glycerine, anti-oxidant, extreme-pressure agent, graphite or molybdenum disulphide. 

Urea has the remarkable property of forming crystalline complexes or adducts with straight-chain organic compounds. These crystalline complexes consist of a hoUow channel, formed by the crystallized urea molecules, in which the hydrocarbon is completely occluded. Such compounds are known as clathrates. The type of hydrocarbon occluded, on the basis of its chain length, is determined by the temperature at which the clathrate is formed. This property of urea clathrates is widely used in the petroleum-refining industry for the production of jet aviation fuels (see Aviation and other gas-TURBINE fuels) and for dewaxing of lubricant oils (see also Petroleum, refinery processes). The clathrates are broken down by simply dissolving urea in water or in alcohol. 

The dry-extmsion process consists of four operations dissolution of the polymer in a volatile solvent filtration of the solution to remove insoluble matter extmsion of the solution to form fibers and lubrication, yam formation, and packaging. 

---