J O H N F. KRASNY and MILTON HARRIS
I / E C
Harris Research Laboratories, 1 2 4 6 Taylor St., N. W . , Washington 1 1 , D. C.
AN NUAL
REVIWW
TEXTILES EXTILE
Tbillion
MILLS
will
spend
$4.5
for fibers in 1960, a n d more t h a n half of this sum will be for m a n - m a d e fibers, according to a r e cent survey. U . S. per capita consumption of noncellulosic synthetics has, for the first time, exceeded that of wool. T h e sales of "wash a n d w e a r " suits—an outlet for m a n - m a d e fibers as well as resin finishes—grew from 25,000 in 1954 to a n estimated 1,200,000 in 1956. These are just a few of the examples of the impact of textiles on chemical producers. T h e r e is not only growth in the consumption of chemical products in this market b u t also sharp declines and reversals. Only 10 years ago, cotton was the r a w material for 6 0 % of all tire cords; in 1955, its share had dropped to 4 % , a n d high tenacity rayon dominated the market (about 400 million pounds annually). But the consumption of nylon tire cord has almost doubled in each of the past 5 years a n d it has been estimated that this fiber will account for 5 0 % of the total within the next 5 years. Similarly, two major changes in chemical consumption have occurred within a very short time period in the floor covering industry. From its birth right after World W a r I I , the tufted carpet industry now accounts for over 4 0 % of the present carpet production, providing a r a p idly growing outlet for latices used in the backing of its products. Secondly, in the same period, wool has lost its predominant position as a carpet fiber, and m a n - m a d e fibers now account for roughly 4 0 % of consumption. This change is, of course, accompanied by a change in the dyestuffs used a n d by a d e m a n d for new finishes, especially of the antisoiling type. 40 A
Fiber Developments
T h e biggest expansion in fiber production, on a poundage basis, is in viscose staple rayon. I n the fully synthetic field, D u Pont announced plans for a new 40 million-pound nylon plant to produce tire cord a n d industrial products, a n expansion of its Dacron polyester fiber plant, a n d at least temporary cessation of production of Orion acrylic filament, while Orion staple production is also to be expanded. T h r e e additional American firms have announced new fibers: American Cyanamid, Creslan (formerly known as X-51), D o w Chemical, Zefran, a n d Tennessee Eastman, Vcrel. Verel a n d Creslan are described as acrylic fibers, chemically modified to provide both ease of
dyeing a n d resistance to heat a n d static. Zefran's chemical composition has not been disclosed b u t it, too, probably has an acrylic base. T h e U . S. is not alone in its rapid expansion in the fully synthetic fiber field. Polyamide fibers are in the planning or production state in 18, acrylics in eight, a n d polyester fibers in seven countries. Six J a p a nese plants are reported to produce poly(vinyl alcohol) fiber (the economics involved d o not seem to favor its production in the U . S. at present). Some details of the Japanese process were published in a n American journal. A Japanese process was described for markedly improving the heat resistance of vinyl fibers by nuclear radiation.
" W a s h and w e a r " cotton fabrics. Left. Untreated, washed, unironed. Treated, washed, unironed, worn 1 d a y (Rohm & Haas)
INDUSTRIAL AND ENGINEERING CHEMISTRY
Right.
Soil resistant treatment o f carpets (American Cyanamid Corp.)
Portable demonstration fire tester. Treated fabric on left chars only when in direct contact with flame (American Cyanamid Corp.)
M a n y new ideas for fiber-forming polymers have been discussed, such as polyamide fibers derived from two-carbon oxalic acid and from four-carbon pyrrolidone, in contrast with the present commercial production derived entirely from sixcarbon monomers. Russian scientists claim to have developed a more heat- a n d ultraviolet-resistant nylon, called Enant. T h e introduction of low-pressure polymerization for making an especially strong, high-melting polyethylene should help its consumption in textiles as well as plastics. A polyester fiber derived from byproduct lignin has reached pilot plant production in J a p a n . A new Swiss nylon fiber, originally described as a "polymer of goat's milk," turned out to be a translation error by a Latin-skilled reporter. H e recognized " c a p r o " as the root for " g o a t , " and " l a c t a m " as the appropriate word for " m i l k " ; hence " c a p r o l a c t a m , " goat's milk. I n fact, of course, it is the monomer for nylon 6. VOL. 49, NO. 1
•
JANUARY 1957
47 A
Finishes T r e a t m e n t of cotton provides the most important market for finishes. During 1955, approximately 600 million yards of cotton fabrics were processed with "wash and wear," a n d 800 million yards with "crushproof" finishes. This trend is continuing upward, and the yardage exceeds the entire production of newer synthetics. The finishes consist largely of urea- and modified ureaformaldehydes, and the melamine resins. O t h e r resin formulations were described as containing acrylic, isocyanate, and silicone products. T w o problems presented by these finishes are fiber embrittlement and chlorine retention. Fiber embrittlement, which leads to reduced serviceability, has been largely overcome by including various lubricants and thermoplastic resin emulsions in the treating formulations. Chlorine retention, which results in discoloration a n d degradation of the cellulose during washing, bleaching, and ironing, is a function of the nitrogen content of the resin finish. Blocking of the nitrogen has reduced the chlorine retention of such finishes, and new nitrogen-free types, such as the acrolein-formaldehyde or cpoxy resins, may ultimately eliminate this problem. T h e epoxy resins cannot, however, at present be removed from the fabric, thus allowing no margin of error for the finisher. Wash and wear finishes which are to be applied by dry cleaners or even in the home to the tailored garment are contemplated; this may give better permanency to trouser creases or pleats than if the treatment is applied to the fabric in the bolt as at present. In addition to the use of treated cotton in light-weight wash and wear suitings, the fully synthetic fibers blended with hygroscopic fibers offer promise of heavier weight, wool-type men's wash and wear suits within the next few years. Such suits m a y actually look better after machine washing and tumble drying t h a n after hand washing and drip drying. New finishes were disclosed during the year to combat such old bugaboos as shrinkage and static. Treatment with a diglycidyl ether is said to halt shrinkage of both wool and cotton fabrics. A British development in wool shrinkproofing employs a combination of pcracetic acid and sodium hypochlorite. A fluoro48 A
chemical latex finish to provide improved resistance to water and oil-borne stains was announced. Flameproofing agents received their share of attention. Diallyl phosphonates were introduced as laundering-resistant finishes which lower tear strength and flexibility of the fabrics to a lesser extent t h a n older finishes. U. S. D e p a r t m e n t of Agriculture chemists reported that an inexpensive triallyl p h o s p h a t e bromoform compound imparted good flame resistance to cotton, which is fairly durable in laundering. Comparing both inorganic a n d organic halogenated flame retardants, this group also found that the effectiveness increased in the order fluorine, chlorine, bromine, iodine, with the last two about equally effective; bromine seemed, however, preferable because of its lower cost and better chemical stability. O n the other hand, some companies reportedly lost interest in bromine- a n d phosphorus-containingflameproofers.
Dyeing T h r e e approaches are used to satisfy the d e m a n d for brighter, faster colors for old and new fibers. First, there is spin (dope) dyeing, which causes a shift from dyes to pigments. Second, modification of synthetic fibers, notably acrylics, permits easier application of conventional dyes. Reaction of acrylic fibers with hydroxylamine is one of m a n y techniques to produce improved dyeability. Others include incorporation of vinyl acetate and vinylpyridine with the acrylic, while some manufacturers use other undisclosed modifiers. T h e third method involves constant development of new dyes and dyeing techniques. A process for printing wool with vat dyes with a m i n i m u m of d a m a g e to the fibers was reported. An outstandingly bright blue dye for cellulosics, based on copper phthalocyaninc, m a d e its appearance, as did a new line of high-fastness dyes specifically designed for polyester fibers. An undisclosed b a t h additive is claimed to overcome difficulties in obtaining heavy black shades on nylon. T h e year 1956 marked the centennial of Perkin's discovery of mauve, which opened the era of synthetic dyes. T h e anniversary was celebrated by a New York convention under the joint sponsorship of 27
INDUSTRIAL AND ENGINEERING CHEMISTRY
technical societies. Even more impressive, perhaps, is the continued intense research effort, in the U. S. and abroad, to provide dyes as longlasting and serviceable as the modern fibers to which they must be applied. Coated and Nonwoven Fabrics, Reinforced Plasties Manifold are the attempts to utilize the specific properties of the various fibers in new end uses. Thus, D a c r o n coated with chlorosulfonated polyethylene has been tried in lightweight fabrics suited for arctic shelters, while fluorinated polyethylene coating for the same fiber provides heat- and chemicalresistant fabrics useful for jet fuel storage. Rubber-coated nylon found two more unusual uses: in the world's first inflatable airplane and as a mold material suitable for rapid, low-cost construction of concrete structures. However, nylon duck seemed to fail to replace the traditional cotton duck for military truck coverings. Nonwoven fabrics—i.e., mats of fibers held together by bonding agents such as acrylic-butadiene copolymer latices, vinyl copolymers, hydroxymethylated nylon (nylon 8), cellulose ethers, and others—are finding increased use in suit interlinings, filter cloth, plastic reinforcement, and as a base for coated fabrics. Interest is shown in use of a wider variety of fibers in plastic reinforcement. Glass, while it has its own processing problems, has thus far dominated the field. Dynel overlays have been used successfully to obtain smoother surfaces than with glass fibers alone. In almost all these developments, the research effort was provided by the suppliers of chemicals, fiber producers, or, in some cases, governmental agencies. It has been estimated that the textile industry itself spends only 0 . 1 % of its sales income on research, compared with an industry-wide average of 2 % , and 5 to 7 % found in some of the growth industries. But there are more and more signs that this will change, as textile industry executives fight to increase their diminishing percentage of the consumer dollar. Enhanced research effort by this industry can result only in even closer and greatly expanded cooperation with the chemical industry.
