Viscose JULIUS B. GOLDBERG J. P. Stevens 0 PROPERLY appraise the effect of the newer
T
& Co., Inc., 350 H d o n S t . , New York,N . Y.
’iscose rayon, exceeding by far all other man-made fibers and yarns in total production and consumption, is certain to retain this lead and find even greater markets with the introduction of nylon, Orlon, Acrilan, Dacron, dynel, and Vicara. Each of these newer synthetics possesses unique characteristics which can enhance fabrics heretofore composed principally of viscose. In combination with this more abundant lower-priced fiber, it is now possible to design fabrics with improved wear resistance, greater dimensional stability, warmth to touch, resistance to wrinkling, loft, and many other desirable properties. The economic factor, too, must not be overlooked, and despite potential reduction in the cost of the raw materials and the operations involved in making the newer testtube textiles, the basic low cost of cellulose and chemicals used for viscose rayon, as well as constantly simplified production methods, are advantages that are not likely to permit any drastic inroads by the increasing family of chemical fibers.
synthetic fibers on the market for viscose, it is important to take note of the present domestic production and consumption of rayon. During 1951, approximately 865,000,000 pounds of all forms of viscose rayon were manufactured in the United Statea. Of this total about 38% was high tenacity continuous filament yarn for tire cord and related uses, with almostanequal amount going into apparel and household fabrics. The balance, approximately 200,000,000 pounds, was in the form of tow or staple fiber. In addition about 90,000,000 pounds of staple were imported, and since exports were comparatively low, there is w a t e d a total consumption of close to 1 billion pounds. By bomparison, production of the newer man-made fibers totaled some 200,000,000 pounds. It has been predicted that the output of the noncellulosic fibers will reach as high as 500,000,000 pounds within 3 or 4 years. While it is evident that the rate of increase in the manufacture of such fibers and yarns is likely to he greater than that of viscose, thcrc are many reasons why the latter can be expertcd to rontinue to forge ahead in the race for leadership. COST FACTORS
It would bc foolhardy to attempt to forecast the probable cost of making the newer synthetic materials beyond the realistic figures which are now available. Existing modern plants in which viscose is currently being manufactured cost much less than any of the completely integrated establishments now under construction for producing the newer materials. Particular emphafiis is placed on tht: factor of complete integration, since some data which have been published on the costs of new plants have not included facilities for manufacturing the monomers or polymers used in tlic spinning of the ultimate fibers. Raw materials costs for the production of viscose are appreciably lower than those for the synthetics with which we are now familiar. Cellulose now sells for from 10 to 16 cents per pound, depending on whether it is derived from wood pulp or cotton linters. New sources of low-cost cellulose are constantly being explored and it is conceivable that the trend will he to somewhat lower prices of this basic material. Caustic soda, carbon disulfide, and mlfuric acid, the principal chemicals used in transforming the purified cellulose to the final product, are likewisc available in large quantities a t moderate costs. Compared with the prices of such materials as benzene, acetylene, cyclohexa,ne, furfural, ethylene, acrylonitrile, acetic acid, acetone, dimethylformamide, xylene, ethylene glycol, zein, formaldehyde, and the many September 1952
other organic raw materials and solvents required to make the nylon, Dacron polyester, acrylic, and azlon fibers, it appears that v i s cose is likely to have the edge on this score for some time to come. PROPERTIES, PERFORMANCE CHARACTERISTICS
We are well aware of the fact that many of the newer “miracle” fibers can yield a better dollar value in some applications, because of their contribution of greater length of life in service, higher strength-weight ratios, lowered maintenance expenditures, or other cost-reducing elemenh On the other hand, i t must be remembered that close tr, two thirds of all man-made fiber consumption is in a p p a r ~ or l household fabrics. As long as the men, women, and children, in this country a t least, are privileged to wear what they like or what fashion dictates, it has been demonstrated that the serviceability of viscose rayon in well-constructed garments of properly designed fabrics is adequate t o meet the competition of the neiver synthetics, the use of which must of necessity add to the cost of such garments. Of prime importance in the rapid increase of viscose production and ready consumer acceptance are the many physical and chemical properties which make i t YO versatile. The strength of today’s rayon is definitely high enough to meet the needs of most applications except in some Hpecial fields of industrial fabrics. Remarkable improvement has been made in recent years and high tenacity yarns are now being spun which are superior in strength to most of the natural fibers. In physical form alone viscose can be made to meet almost every known requirement. It is possible t o extrude filaments of extreme fineness and suppleness or of coarseness and rigidity, in any degree of luster, dopedyed, with cross srctions ranging from almost circular to flat and even hollow, and with a predetermined amount of durable crimp. Elongations can be varied widely for specific requirements and in some instancrs experimental fibers and yarns have been made with greatly reduced iwt-swelling characteristics or with modified dyeing properties. If some day we are offered an all-green viscose, it will not be the result of envy of other manufactured fibers but merely because someone has found another use for chlorophyll. Whiteness has generally been regarded as a symbol ofpurityand virtue, and viscose has always rated high in this respect. At least any failings along thrse lines can usually be remedied by simple inexpensive bleaching methods with no serious complications. Soil removal from garments or household fabrics composed of viscose is good with conventional laundering or dry-
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cleaning procedures and the problem of pilling encountered in spun-yarn fabrics of some of the newer synthetics is virtually nonexistent. Latitude of dyeability is an attribute possessed by viscose which is certainly the envy of every one of its newer textile associates. Rayon fabrics can be dyed or printed with the widest variety of dyestuffs and to any degree of brilliance with color fastness properties t o suit any need-and a t the lowest cost. In blends with the other man-made fibers it is possible to keep the viscose undyed or white without any appreciable staining or to obtain attractive cross-dyed effects. Woven fabrics can be stabilized against excessive shrinkage or stretch in use or in continued laundering or dry cleaning, by any one of several practical, reasonably priced chemical finishing methods, Resistance to wrinkling or greatly improved recovery from creasing and temporary or durable water repellency can be achieved through relatively simple chemical treatments. Heat resistance is superior to that of most of the newer synthetics so t h a t no special precautions are necessary in ironing apparel fabrics to prevent their glazing or sticking. The creping power of viscose yarns is a property not found in any of the other manmade fibers, unless some costly unorthodox techniques are employed. While the resistance of viscose to mildew or bacteria and flamma,bility is generally inferior to that property of itsnewchemiea);cousins, the application of materials to guard against deterioration or ignition and burning mag he readily accomplished in a practical manner. Moisture absorption of the regenerated cellulose fibera is high as compared with that of nylon, Dacron, and the acrylics, but with the exception of the advantage of rapid drying of washable fabrics, in most apparel fabrics this hydrophobia is not only unnecessary but often detrimental to certain end uses. The foregoing brief reviexi- of the many desirable features of viscose has been presented to stress the firm foundation and sturdy fortifications which any new synthetic textile material must face if there is any thought of achieving supremacy in the field of man-made fibers. ADVANTAGES O F THE NEWER FIBERS
With all of these attributes in viscose we still recognize the unusual merits of the more modern supernatural fibers. We cannot overlook their importance for industrial uses where chemical resistance makes their performance outstanding or in certain household and apparel fabrics where ease of care is of sufficient importance to justify the higher cost of the fabricated article. There are certain areas in which viscose rayon appears to be strongly entrenched and no great inroads on these markets by any of the newer synthetics are anticipated. Specifically these include tire cord, where, as indicated earlier, the present market consunies over 300,000,000 pounds annually, garment linings taking over 40,000,000 pounds, and the increasingly important markets of carpeting and automobile interiors. A t the same time a loss of perhaps up to 5,000,000 pounds must be expected in lingerie fabrics and it is quite likely that in the field of curtain fabrics more ground will be yielded. The hosiery trade showed a tremendous reduction in rayon consumed from 1942 to 1949. With under 6,000,000 pounds now being used by this trade it is not likely that further losses could be very great.
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Assuming that the large price differential is likely to be maintained for many years ahead, it seems obvious that the newer fibers will serve to stimulate even greater use of viscose by imparting some of their unique characteristics t o fabrics in which they are incorporated either as blends or in combination yarn constructions. For example, experience has taught us that nylon has no equal in its resistance to abrasion, and in woven or knitted materials where serviceability and performance are materially affected by rubbing or chafing, the addition of comparatively small percentages of this polyamide fiber is undoubtedly opening the door for greater consumption of viscose rayon. Outerwear apparel has provided a sizable outlet for viscose rayon in recent years, but the added features of nylon content have done a great deal t o make such fabrics even more acceptable. As we profit by experiences with fabrics in actual service, it is reasonable to assume that as long as we are dealing withacostlier “additive,” the proper amounts of nylon needed will eventually be accurately established and the absolute minimum used to achieve the desired advantages. Just as the part-wool blankets made with 95% cotton and 5% wool have questionable merit, constructions containing such small amounts of the newer synthetics to make them attractive from a promotional viewpoint only are existent as growing pains in any children, and it can be assumed that they will be outgrown if not outlawed by gradual consumer education. The acrylic fibers are unusual because of their high bulking power, pleat and crease retention, and resilience, and the judicious use of certain percentages of such synthetics in combination with viscose has opened new fields for the latter. Likewise, Dacron shows promise of contributing to the liveliness and shapeholding properties of viscose fabrics and it, too, can be expected to add to the consumption of the ever-popular rayon. Vicara posseses such attributes as softness, warmth to touch, and resilience. While it is admittedly too IOTV in tensile strength t o be used t o any extent by itself, it does enhance basic spun viscose staple fabrics for certain end uses and promises to result in the creation of blends which can further expand the market forviscose. To a great extent, the Vicara manufacturer’s slogan, “The fiber that improves the blend,” actually sounds the keynote for the anticipated growth in the consumption of viscose rayon through the use of all of the new synthetics. Dynel, the polyvinyl chloride-acrylonitrile copolymer, also has many unusual properties which can be utilized to modify the handle and performance of viscose and it, too, should result in greater outlets for the lowest priced man-made fiber. As long as the newer synthetics possess unusual dyeing properties, viscose can always be relied upon to be useful in combinations to yield attractive cross-dyed effects, so in their dyeing limitations, too, there is a characteristic which is likely to maintain or increase the demand for viscose. Viscose is still the king of man-made fibers, and it will take more than a mild revolution led by the new fibers to depose this ruler or cause any severe loss of the empire built up during the past 40 years, The newer man-made fibers are providing us with fabrics which are indeed unusually serviceable, stable, crease resistant, easy t o care for, and luxurious to the hand. We appreciate their virtues and bow to their charms, but for the present and immediate future they may be regarded as the pastries of our dmner table. We are happy to sweeten our diet but they are not likely to supplant our daily bread, viscose rayon. RECEIVED for review M a r c h 31, 1952.
ACCEPTEDJuly 7 , 1952.
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 44, No. 9
