Vinal fibers

Vinal fibers, or poly(vinyl alcohol) fibers, are not made in the United States, but the fiber is produced commercially in Japan, Korea, and China where the generic name vinylon is used. These materials are the subject of this article (see also Vinyl polymers, vinyl alcohol polymers). 

Vinal fiber n. A manufactured fiber in which the fiber-forming substance is any long chain synthetic polymer composed of at least 50% by weight of vinyl alcohol units and in which the total of the vinyl alcohol units and any one or more of the various acetal units is at least 85% by weight of the fiber (FTC... 

Vinal fibers are made from polymers containing at least 50% vinyl alcohol units and in which at least 85% of the units are combined vinyl alcohol and acetal crosslink units. The fiber is inexpensive, resembles cotton in properties, and is produced in Japan. 

Fibers q)un from H insolubilized by aldehydes Vinal fibers"... 

Another vinyl-based fiber, polyvinyl alcohol, or vinal, was developed in Japan but has not been produced or used in the United States. As such, it illustrates the importance of both relative availability of raw materials and differences in markets, in the success of a chemical product. Acetylene made from calcium carbide is converted to vinyl acetate, which, following polymerization, is saponified to polyvinyl alcohol. 

A process has been developed in Japan for producing fibers from poly(vinyl alcohol). The polymer is wet spun from a warm aqueous solution into a concentrated aqueous solution of sodium sulfate containing sulfuric acid and formaldehyde, which insolubilizes the alcohol by formation of formal groups (see below). These fibers are generally known as vinal of vinylon fibers. 

The fibers are supplemented by the reaction product, coated with natural mbber or SBR and vinal pyridine latex. During the subsequent drying procedure at 150-230 °C, the methylol group reacts with both the fiber surface and the active molecule groups of the rubber. The rubber bonded to the fibers is also cross-linked in the subsequent vulcanization process. 

Vinyl fibers are those man-made fibers spun from polymers or copolymers of substituted vinyl monomers and include vinyon, vinal, vinyon-vinal matrix (polychlal), saran, and polytetrafluoroethylene fibers. Acrylic, modacrylic and polyolefin—considered in Chapters 8 and 9—are also formed from vinyl monomers, but because of their wide usage and particular properties they are usually considered as separate classes of fibers. The vinyl fibers are generally specialty fibers due to their unique properties and uses. AH of these fibers have a polyethylene hydrocarbon backbone with substituted functional groups that determine the basic physical and chemical properties of the fiber. 

The vinyl fibers, with the exception of vinal and vinyon-vinal matrix fibers, are extremely hydrophobic and difficult to dye, and consequently they can be dyed only through pigmentation of the polymer melt before fiber formation or through dyeing with disperse dyes. Vinal and vinyon-vinal matrix fibers dye readily with dyes used on cellulosics including direct, mordant, reactive, vat, and sulfur dyes. 

Vinyl fibers except for vinal and vinal-vinyon do not generally undergo specialized finishing, although antioxidants and antistatic agents may be used. Vinal and vinal-vinyon matrix fibers can be treated with urea-aldehyde based durable press finishes to improve their wrinkle recovery, and vinal can be made flame retardant with phosphorus-containing finishes used for cellulosics. 

ISO, lUPAC) VY Vinal ( = poly(vinyl alcohol) fiber)... 

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