Spin finishing

The air jet textured yam process is based on overfeeding a yam into a turbulent air jet so that the excess length forms into loops that are trapped in the yam stmcture. The air flow is unheated, turbulent, and asymmetrically impinges the yam. The process includes a heat stabilization zone. Key process variables include texturing speed, air pressure, percentage overfeed, filament linear density, air flow, spin finish, and fiber modulus (100). The loops create visual and tactile aesthetics similar to false twist textured and staple spun yams. 

Nylon is the preferred fiber for flocking because of its good chemical bonding to a wide range of adhesives, its toughness, and its ease of dyeabiHty and printabihty. Nevertheless, the tow must be manufactured with the proper ktex, cohesion, and spin finish to be readily converted to flock (133). 

A number of disinfectants apparentiy owe their activity to formaldehyde, although there is argument on whether some of them function by other mechanisms. In this category, the dmg with the longest history is hexamethylenetetramine (hexamine, urotropin) [100-97-0] which is a condensation product of formaldehyde and ammonia that breaks down by acid hydrolysis to produce formaldehyde. Hexamine was first used for urinary tract antisepsis. Other antimicrobials that are adducts of formaldehyde and amines have been made others are based on methylolate derivations of nitroalkanes. The apphcations of these compounds are widespread, including inactivation of bacterial endotoxin preservation of cosmetics, metal working fluids, and latex paint and use in spin finishes, textile impregnation, and secondary oil recovery (117). 

In addition, if used in spin finishes they must be thermally stable, oil-soluble and exhibit low migration on the fibre. 

Commercially produced nylon 66 core fibers were washed with water to remove the spin finish and then pretreated with two different coupling agents l,4-bis(3-aminopropyldimethylsilyij-benzene (APDMSB) obtained from Petrarch, and fumaric acid (FA) ... 

Spin quantum number (s or /n5)—This number describes the apparent spin of the electron. The term apparent spin is used since the atom behaves magnetically as though it were a spinning object, but the wave-like nature of the electron makes such spinning difficult to comprehend. Only two values for s are possible I Jj and — (corresponding to clockwise or counterclockwise spins). Finishing the house analogy, we can see that in an atom, no two electrons can have the same four quantum numbers. In much the same way, no two houses can occupy the exact same address at once. 

Softener and processing aid for synthetic and natural fibres. Used as a spin finish on acrylic fibres and as a softener on both natural and synthetic fibres. It is particularly effective on acrylics but gives a pleasing soft silky handle on nylon. It is recommended as the softener for chlorine/resin finished wool to overcome the harsher handle resulting from such processes, to aid processing and give a lofty hand. 

EMEREST Glycerol Esters are based on fatty acids. In the leather and textile industries, they are used as components in lubricants, softeners, and dye carriers, and as co-emulslfiers for synthetic fiber spin finishes. Industrial applications include uses as lubricants, rust preventatives, and mold release agents. 

Has a monoester content of 50-60%, free glycerol 1%, and moisture 1%, maximum. It is used as a component in mold release agents, a vehicle for agricultural insecticides, an anti-icing fuel additive, and a rust preventive additive for compounded oils. It is used in the textile industry as a lubricant component in synthetic fiber spin finishes. 

Is a versatile O/w emulsifier and solubilizer of petroleum oils, solvents, and fats. High water solubility enhances its ability to solubilize petroleum solvents. In the textile Industry it is used as an emulsifier for dye carriers, as an antistatic scrooping agent in primary spin finishes, and as a fiber processing aid. 

Is a water-soluble surfactant used as a base lubricant for synthetic fiber spin finishes, open end spinning, and overspray finishes. It is also an excellent co-emulsifier and coupling agent for many formulations. 

Is used in the textile industry as an antistat and lubricant for wool and synthetic fiber processing, and as a co-emulsifier and antistat in synthetic fiber spin finishes. It is also an anti-precipitant, leveling, and migrating agent in various dyeing procedures, and an antistat in carpet shampoos. 

Non-red label solvent scour for the removal of oils, spin finishes, and other lubricants from polyester and other synthetic fibers. Low foaming for use in high turbulence equipment. 

Melt or solution spinning of synthetic fibers is a marvel of modern technology. Fiber lubrication, which is of the utmost importance in this high-speed process, is achieved by the application of spin finish—a combination of oils and surfactants. A typical spin line for the production of polyester staple fiber is shown schematically in Figure 2. The number of filaments, which can vary from tens to thousands, come into contact with various parts of the machinery, some of which are heated for proper fiber modification. To replenish the lost finish and to ensure adequate lubrication,... 

The commercial importance of spin finishes can be realized from the sheer volume of synthetic fibers produced. For the year 2000, the production figures of the three major synthetic fibers, e.g., polyester, polyamide (nylon), and poly(acrylonitrile) were approximately 18, 4, and 3 million tons, respectively (51). If spin finishes are applied at 0.25-0.5% level, the annual requirement of these finishes will be in the range of 70-140 thousand tons. This has given rise to industries that supply spin-finish components and completely formulated spin finishes for specific applications (52). An experimental nonproprietory spin finish formulation supplied to TRI/Princeton by Henkel Corp. follows ... 

Apart from lubricants, spin finishes contain antistatic and spreading and emulsifying agents. These are generally alkyl sulfates, alkylbenzene sulfonates, sulfonated fats and oils and poly(ethylene glycol)-modified fatty acids, fatty acid amides, fatty alcohols, and fatty amines. Potassium alkyl phosphates are extensively used in the production of polyester staple fibers. 

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