JOSEPH L. VODOKIK Industrial Rayon Corp., Cleveland, Ohio
ROBERT S . CASEY W . A . Sheufler Pen Co., Fort Madison, Iowa
C. S. GROVE, JR. Syracuse L‘niuersity, Syracuse 10, N . Y .
Considerable emphasis during the past year has been on synthetic fiber and cotton research, resulting in modifications that increased fiber utilization in industrial processes. Cyanoethylation of cotton has markedly increased many advantageous factors. Overexpansion of production facilities has shown itself in a depressed market, which can only be relieved by working with industry to provide new uses for fibers as materials of construction. New finishes, new coatings, and new treatments highlight these efforts to penetrate and open up potential new markets for increased fiber consumption,
UCK (7) in discussing the effect of the synthetic fibers on cotton and the other natural fibers has said:
Of course, fibers must always have affected each other t o some extent, but the rather distinct separation of the four principal types-cotton, linen, wool, and silk-into different brackets of economy and luxury, minimized to a great extent interfiber competition. Tradition in fiber use, geographical considerations, and living habits, and availability of not only the fibers but of technicians with the know-how for processing them, also tended to make competition among fibers unimportant for many centuries. The first half of the twentieth century brought a rofound change to the textile industry. The rapid increase in t i e use of the semi-synthetics, rayon and acetate, from about 1920, and the introduction of the true synthetics, nylon, Dacron and the acrylics in the late ’30’s and ’40’s more than doubled the fibrous raw materials available to textile mills, S o t only did the number of textile fibers increase, but also the range of physical and chemical properties which could be obtained from them. These new fibers with their new performance characteristics have already profoundly affected the natural fibers, as may the development of additional man-made fibers or any extension or improvement of their use characteristics. I t is impossible today to discuss realistically the position of any fiber, natural or synthetic, without taking into account the influence upon it of other members of the now considerable textile fiber family. This holds true in the field of textile economics, including matters of supply, demand, pricing, and marketing, but particulaily in the technological field where objectives of research studies, the evaluation of research results, and even the decision on the introduction of new products are highly dependent upon the cost, availability, and quality of competitive materials. Rutledge (67) describes hox a fiber can penetrate the industrial market, using as an illustration the experience of Orlon acrylic fiber in the field of dry filtration. The great increase in use of Orlon in dust collection bag proves the claimed advantages of Orlon. These advantages, such as good heat and acid resistance, high strength, and good flexing characteristics, function as a primary requisite in industrial fabric. If a fiber can perform, it gets the job. Longer life and fen-er shutdowns for changes are important. Here is where the greater strength, higher abrasion resistance, chemical stability, and many other plus properties of man-made fibers show their superiority. The growth of high tenacity rayon yarn consumption in the tire industry offers another case history ol hovi a man-made fiber, providing specific sought-after properties, penetrates an industrial market. Ut’ilization of such fibers in work clothes is favored by the functional aspect. Safety of these dotiles is the important factor; appearance is only secondary. 2016
SYNTHETIC FIBERS RESEARCH
Mauersberger (55’) states in his introduction to “Matthews’ Textile Fibers” that today the textile industry is the second largest peacetime industry of the nation. Many 1aborat.ories throughout the country are conducting research on fibers now known and are constantly endeavoring to develop new ones. A tremendous advance has been made in the development of manmade fibers. Although there still remain gaps in our fiber technology, the eubject has expanded considerably since the early pioneering of the original investigators. According to Quig ( 6 4 ) in his discussion of the technical developments leading t o the present man-made fibers the progressive industrialization of the world calls for functional fibers as it has for functional metals, plastics, paints, dyes, and other materials. The future of man-made fibers hinges upon this concept. It is certain that success r i l l come t o those fibers possessing the greatest measure of useful distinctiveness and the most favorable relationship of performance to cost. Kester (43) discusses “Spinning Dreams into Yarn” and states that the search is on in D u Pont laboratories for unique fibers of all types. Fibers stronger than any now known, ones with extremely high elasticity, fatigue resistance, or flame resistance, all t.hese qualities and more, are being sought. Whether any of these superior fibers, once found, will have an industrial future is almost impossible t,o predict. The first problem is to make them on a small scale so that they can be evaluated. In research development it must be recognized that a new fiber must have most of the advant.ages of existing ones for a given use, plus a few more. Buchanan ( 6 ) , discussing this same subject before a Denver audience, stated that research on man-made fibers is important, but emphasized as always, in America, it will be consumers who decide by their purchases what kind of fabric ill be made, and neither the sheep nor the silk worm nor the Du Pont Cn. is going to have much t o say about it. Dillon (%?) on current problems and future trends in synthetic fibers states that the impact of modern chemistry on t.he three essentials of life-i.e., food, shelter, and clothing-has thus far been rather puny. The replacement of natural matcrials by the synthetics as basic elements of construction is most advanced in the textile industry Any synthetic fiber must meet. three basic requiremects, availability, reasonable price, and superior properties for a t least one important application, if it is t o survive. He discusses many of the properties that these fibers must have and indicates how the nev synthetic finers can mect these requirements. He concludes that the synthetic fibers xi11 continue to encroach more and more on the domain of the natural fibers in induytrial fabrics where the principal demands on a fiber are availability and performance por dollar; and the fie!& yardsticks of style, subjective reaction, and promotion play miiior roles.
October 1954
INDUSTRIAL AND ENGINEERING CHEMISTRY
Goldberg (31) in an annual review of textile research achievements in 1953 states that, in spite of a depressed market, research in textiles from new fiber developments and old fiber improvements to the finishing of fabrics has not been dormant and the record of last year’s achievements is no less impressive than that of previous years’. Freedman (28) states that on the whole the man-made fibers are meeting with increased consumer acceptance, and that they are not presenting, in so far as consumers are concerned, any problems that have not been previously encountered with cotton, wool, linens, silk, rayon, or acetate. However, some problems that do exist and must be met in order to get complete consumer acceptance are due to:
1. Exaggerated claims in advertising and sales 2. A desire t o obtain a larger share of the market or to make a higher rofit by producing an inferior product 3. I)nsufficient knowledge on the part of the fiber producer, textile manufacturer, dyer, finisher, ,garment maker, advertiser, retailer, and the public, as to the attributes and the limitations of these man-made fibers 4. Gullibility of the public Pranal(63) discusses the relation of the chemical industry and textiles in Europe. Textile and chemical industries become closely related and more interdependent when the manufacture of fibers of the so-called man-made type is considered. Starting with fibers such as viscose and acetate and proceeding to the latest synthetic fibers, he stresses the growing importance of chemistry which though once a mere auxiliary of the textile industry, is now more and more playing the leading part. Moncrieff (60) in his new edition of “Artificial Fibers” reviews both old and new fibers. Two of the outstanding developments in the fiber industry of recent years have been the introduction of new methods of dyeing; and the great strides made by the stable fiber advancement in artificial fibers in changing in direction from artificial silk to artificial wool. For the future two trends are already clear; one, attention will pass from the synthesis of hydrophobic to that of hydrophilic fibers. New fibers which will be more like wool will be made. Two, the fiber industry is slowly but surely passing into the hands of the giant chemical groups. Evidently it is easier for the chemical manufacturer to learn the spinning technique than it is for a spinner to learn how to make chemicals. One other trend which is clear, but which it is hoped will not persist, is the increasing secrecy that surrounds the manufacture of some of the newest fibers. Goldberg (29, SO) in outlining textile progress and textile research achievements in 1953 mentions Du Pont’s new Teflon tetrafluoroethylene polymer as a fiber-forming material, Goodrich’s Zetek, which is a vinylidine cyanide fiber; D u Pont’s 109, which is a low wet swelling tough rayon. American Viscose has developed a new round cross-section, double delustered carpet rayon, featuring great soil resistance. From abroad come reports of a Dutch acrylic staple; Japanese nylon with a fluted outer surface; high tenacity rayon staple; a polyamide staple; a new polyvinylchloride yarn originating in Italy; and German Trelon, reputed to be softer than nylon or Perlon. Many developments have been made available through research on the natural fibers, such as treatment of cotton yarn with acrylonitrile t o yield cyanoethylated yarns with improved tensile strength, elongation, resistance to dry heat degradation and abrasion, along with permanent resistance to microorganism attacks. Science has even increased the silk output of the lowly silk worm by feeding them aureomycin and chloromycetin. Somers (72) has described progress with new polymers such as the isocyanates and their modifying effects on other polymers. Isocyanates are a versatile class of organic substances; they may form the basis of textile auxiliaries, of new types of permanent finishes, or of new fibers themselves. Perlon U is a type of
2077
outstanding synthetic fiber that can be made by the use of organic diisocyanates. Somers (7’1) describes new methods for making polyamides from new intermediates. Ellsworth (24) describes a new process for improving dimensional stability of rayon that was developed by pulp and paper industry researchers for prevention of dimensional changes in cellulosic materials due to moisture. The Upson process consists of treating cellulosic materials with a selected group of monoesters that are formed in the course of alkyd resin manufacture and that, oddly enough, have previously been considered undesirable by-products. The essential step is a thorough impregnation of the cellulosic material with the stabilizing agent. A modification of viscose rayon, chemically or physically, that results in lower moisture absorption, might well result in undesirable physical properties since moisture absorption and swelling are important where dyeing, body comfort, and a minimum generation of static are concerned. COTTON FIBERS RESEARCH
Like any important man-made structural material, modern industrial textile fibers ( 7 4 ) are created by engineers using scientific precision methods t o produce fabrics that will properly perform specific mechanical tasks. To achieve these results the textile engineer works with these basic variable elements, fiber, yarn, and weave. Much depends on the choice of fiber or fiber combination and the particular form of the fiber, whether it be in the form of staple, like the short fibers of cotton or wool, or in the form of filament like the continuous strands of silk. Of all industrially used fibers, cotton is still king, partly for economic reasons. To industrial users, thinking in terms of continuity of supply, cotton is attractive because of its widespread availability due to enormous production, and also because in spite of price fluctuations it is a relatively low cost raw material. Cotton’s spectacular leadership is due to outstanding physical properties. Cotton fibers have a natural twist which provides excellent spinning qualities resulting in strong yarns. An extremely durable fiber with good stability against stretching, it is highly resistant to degradation by heat and has good bulking and insulating qualities. High wet strength together with absorbency which causes the fiber to swell when wet results in excellent fabric performance under moist conditions. Cotton fabrics lend themselves to finishing processes providing water repellency, dimenAional stability, resistance to mildew and flame, improved electrical qualities, and other special requirements, Compton (1%’) discusses importance of cotton and processes of mercerization, cyanoethylation, and acetylation, which improve certain properties of cotton, such as dye-acceptance, resishance to mildew, abrasion resistance, and heat resistance. According to Smith (70) cotton, long considered an unchanging and unchangeable textile fiber, is becoming a new, different, and more useful textile raw material. Producers of synthetic fibers admittedly have been attempting to duplicate some of the fine qualities of cotton, its moisture absorptivity, its launderability, its relative freedom from static. By the same token, the cotton industry has been trying to learn how to modify cotton to produce some of the qualities of the synthetics that are desirable in particular applications, their speed of drying, loftiness, and luster. Cotton is responsive to virtually all the techniques that can be applied to the chemical fibers except one-that is, continuous extrusion. Finally, cotton can be improved by techniques not applicable to synthetic fibers, genetics and selective beeeding. McNamara (50) has described the latest chemical modification process for cotton-cyanoethylation. According to the release, the treatment of cotton with acrylonitrile has resulted in a new family of partially cyanoethylated cotton fibers that are similar in appearance, hand, and processing characteristics to cotton, but significantly different in that they are:
2078
INDUSTRIAL A N D ENGINEERING CHEMISTRY
1. Permanently resistant to microorganism attacks such as mildew and bacteria 2. More resistant t o wet and dry heat degradation 3. More recept'ive to all classes of dyes, including acid dyes 4. More resistant to abrasion
Partial acetylation of cotton fabric yields a fabric characterized by having ; 1. Resist'ance to microorganism attack 2. Resistance to dry heat degradation 3. Low moisture regain and high electrical resistance, and 4. Resistance to coloring with many direct dyes Resin treat'ments of cotton fabric are not commonly regarded a8 reacting chemically with the cellulose components of the cotton fiber. Propert.ies of the cotton fiber are modified so as to greatly enhance its marketability. Among some of the thermosetting resins that are being successfully used in emboseing, glazing, polishing, and in the crease-resistant finishes are: 1. Urea-formaldehyde or glyoxyal resins 2. Melamine-formaldehyde resins 3. Various aldehyde-ketone condensates
Reeves, McMillan, and Guthrie (65) reviewed the chemical and physical properties of aminized cotton and state that aminized cotton takes on most cotton dyes very rapidly; some of these, especially direct dyes, are more resistant to light and laundering on aminized than on untreated cotton. Combustibility of aminized cotton can be reduced either by application of dyes containing a phosphate or a sulforadical or by reacting the amino groups with tetrahydroxglmethylphosphoniumchloride. Certain metals react with the amino groups to form metal complexes that have oxygen exchange propert,ies. Buras, Cooper, Keating, and Goldthwait (G) describe the practical partial acetylation of cotton to improve heat and rot resistance. Data on the concentrat.ion of chemicals used, duration of treatments, temperature, and other operating conditions required for best results are present,ed. Hamlin (37) surveyed the literature on finishes for cellulosic textiles giving permanent protect,ion against microbiological attack; 44 references are included. Much work has been carried out on this protection of cellulosic fabrics from microbiological attack, both by means of inert physical barriers around the fibers, and by chemical modification of the cellulose molecule. Either method gives good protection, even during weathering, but in each case there are considerable drawbacks. The former method is quite useless unless the harrier is kept intact, and this is very difficult to achieve where the fabric is subject t o flexing. The latter method is undoubtedly a very inefficient method of proofing; unless t,he chemical reactions are carried out most carefully, the fabric loses strengt,h and is more susceptible to damage by repeated flexing. The ideal permanent proofing treatment against microbiological att,ack has by no meane been achieved. Compton and associates ( I S ) described new textile fibers created by reaction of cotton with acrylonitrile. Hansen and Bergman ( 3 8 ) give a general description of the microbiodecomposition of cellulose followed by an account of various mildew-proofing treatments and applications of toxic inhibitors to textiles. Yeager ( ? 7 )has comment,ed on the following properties that need t o be t,aken into consideration n-hen choosing fungicides for application to textiles, stability, toxicity, color change, efficacy, odor, and effect on handle of fabric. These properties are given for 15 different fungicides. The Treesdale Laboratories (14)report that laminating cotton with aluminum foil produces a ne\T fabric that resists temperatures of 450' F. FIBER MARKETS Ai3D PROSPECTS
The fiber market's are among the world's greatest, with poundages running into the billions of pounds. In our country, synthet,ic fibers have become a iamiliar part of every day life, yet they Etill account for only a minor percentage of the total vast
Vol. 46,No. 10
market,. There are eo far only t x o major types of synthetics, t'he cellulosic and the polyamide. There is, therefore, plent,y of room for growth either for these or for the newer synthetics. Growth of cellulosics, however, seems to be stopped a t least for some years by the growth of nylon, and now by the indicated growth of Dacron, polyester fiber, plus also great improvement in the finishing of cottons, and, finally, plain overexpansion of production. X o d e r n Textiles (68) reports that man-made fibers produced in the United States during 1953 totaled 1,497,000,000 pounds, an increase of 7% over 1952, but slightly under the record high output of 1951. Viscose and cuprammonium output, were up 8.5% during the year, but acet'at,ewas d o m 3%. Koncellulosic fibers, however, showed a 14% gain to reach a new record despite a sharp decline in staple and tow production in the last half of the year. -4preliminary computation of world rayon and acetate fiber output estimates that the total during 1953 v a s 4,090,000,000 pounds, a new record exceeding by 1.5% the product,ion in 1951, which was the previous record year. Shipments generally lagged behind production during the year, with the result that producers' stocks a t the year end xere slightly higher in all categories except regular and intermediate tenacity rayon yarn, where they were slightly lower. Total rayon and acetate shipments in 1953, amounting to 1,168,700,000 pounds, were close to the 1952 figure on shipments, which was 1,160,500,000 pounds. They T-iere 8% lower, however, than the peak shipment figure of 1,268,500,000 pounds in 1950. It is also estimated that 1953 imports show that the imports represent 6% of the total available supply, a percentage figure similar to that of 1952, but 2 percentage points less than in 1951. Soncellulosic production figures last year were 300,500,000 pounds which represents an increase of 14% over the previous year. The noncellulosic fibers include acrylic fiber, nylon, polyester fiber, polyethylene fiber, polyvinyl acetate fiber, protein fiber, saran, and textile glass fiber. A review of the synthetic fiber industry indicates that Dacron is very likely to prove a major fiber, perhaps ranking eventually with nylon, that nylon is still in a vigorous growth trend and likely in various degrees to add noticeably to the fortunes of Du Pont, Rfonsanto, American Viscose, American Enka, Allied Chemical, Industrial Rayon Corp., and the Erlanger Corp., that the acrylics are likely to have another year of difficult going before being in a position Lo prove themselves but. when they do, the total market may be clinched between four or more companies. Nevertheless, there should be a good place for these fibers in the textile industry, and the huge supply of acrylonitrile enthujiastmically built up by the chemical industry should eventually be absorbed by these fibers and by other uses. The Kovember 1953 capacity of the United States for manmade fibers was slightly over 2 billion pounds, on an annual basis. It is expected that this will increase to 2.22 billion pounds by July 1954; 2.27 billion pounds by March 1955; and 2.32 billion pounds by October 1985. If one compares these potential production figures with the previously estimated consumption figures, one can realize t,hat the market for textile fibers is tending toward a depressed state. This state of depression may permit the engineer to consider fibers for uses where they were formerly not considered because of unavailability and the price structure. The rayons seem to be in for a long period of readjustment. They are faced wit.h competition from nylon and Dacron, and to a lesser extent from other synthet'ics, and also from greatly improved natural fibers, especially cotton, and silk also is reappearing on the market, The indications are that the pattern in fibers will in the next 12 months become set for some years. DuPont announced latein April that the prices for Orion acrylic fiber continuous filament were reduced. Earlier in 1954 the Filament Denier 75 100 200
Price, 3/Lb. Former Reduced 3.65 3.25 2.50
2.65 2.35 2.25
October 1954
INDUSTRIAL AND ENGINEERING CHEMISTRY
price of Acrilan was reduced 45 cents a pound. The prices of Orlon fiber had been reduced earlier this year. The new price of $1.40 a pound on Acrilan fiber appeared intended to enable the fabric trade to offer fabric to volume cutters a t prices they could pay, it was added. When the Chemstrand Corp. plant, making this fiber, gets into full operation it will have a capacity of 30 million pounds per year. Chace (10) declares that the post World War I1 planning for production of man-made fibers was based largely on a stepped-up economy, increased population, the change of consumer buying habits influenced by leisure, comfort, and ease of care. This planning duly recognized the perfection of chemistry with the incorporation into new fibers of increased resistance to wear, fabric dimensional stability, iron-less care, permanent injection of color, and all the newer or recently developed characteristics. The plans accurately predicted the necessity of more exact manufacturing conditions, the more exact controls of temperature, humidity, strain and stress, to transpose the new fibers and yarns into high quality fabrics both for textiles and industrial uses. The need was recognized for labor-saving methods t o offer more pounds for the dollar. Due consideration was given to the increased capital necessary to finance the operation of new plants, new machinery, new methods, and most importantly, the reduction of capital turnover with respect to the dollar volume of gross sales, The money was invested, the new plants were built, the production was increased, and yet profits declined. He further states that the following basic errors committed within the industry were responsible for the depressed state of the industry: 1. Too much of the old 2. Too much stress on increased production as such 3. Too little attention to style and season 4. Too much hunger for extraordinary profit 5. Too little advance in dyeing and finishing technique and perfection 6. Too fast with too much a t too high a price on the new manmade fibers, with production and price overriding perfected performance
Martin (68)states that continued developments in the manmade fiber business need to be based on a follow-through to the consumer, He predicts that continued progress will be made in 1954 but not a t the rate many might desire. For several years after World War I1 there appeared an illusion that textile markets were prepared to accept ever increasing quantities of manmade fibers, when actually pipelines were only being filled and the natural level of consumption of the economy was built up to run smoothly in high gear. It is to be hoped that 1953 witnessed the final shattering of this illusion, and that now it is understood that the progress which lies ahead will be largely of the industry’s own making. Man-made fibers have the vitality and versatility to go forward on many, many fronts, but the rate a t which these achievements are gained depends on the intensity and thoroughness which see the various products and responsibilities through the consumer satisfaction. This indicates the opportunity ahead for the engineer and the industrialist to adapt and adopt the new fibers for industrial uses. INDUSTRIAL USES
Lake (17) expressed the view a t a symposium of the American Association of Textile Chemists and Colorists that the surface of potential industrial uses for fibers has only been scratched. Mersereau (16)mentions that it may not be generally realized but there are relatively few true blends of synthetic fibers used in industrial textiles. Despite the fact that the synthetics are getting progressively stronger in this important branch of the market, the purpose of using a fiber in an industrial application is, in most cases, to employ one particular physical property. Some of these properties are strength, chemical resistance, abrasion resistance, and freedom from dimensional change under varying conditions. A homogeneous blend will normally be only as
2079
valuable as a poor component under any specific condition, Therefore, if a strong fabric is needed, the tendency is to use 100% of the strongest available fiber. Stoll (73) compares the end use requirements versus material properties of textiles and divides the end use requirements of most fabrics and other textile products into nine major categories: 1. 2. 3. 4. 5. 6. 7. 8. 9.
Esthetic appeal Ease of handling Form stability Physiological requirements Special functional requirements Retention of esthetic appeal Resistance to chemical degradation and disintegration Resistance to mechanical fatigue and wear Ultimate strength and resistance to wear and tear
Tn order to achieve these end use requirements, the fiber properties should be divided and considered in four categories: 1. Inherent properties of the fiber material 2. Geometric form of the individual fibers 3. Physical properties of the individual fibers 4. Characteristics of bulk fibers
X o d e r n Textiles (61) has announced its new handbook, where all the basic information of the new fibers has been gathered into a single handy reference volume. hIoisson (60) states that because of the number of synthetic fibers now available, the volume in which they are used, and the variety of products they go into, more people need information about fibers than ever before. He presents a 1953 synthetic fiber table that reflects two years of research. This table has a terminology and reference section, with a regrouping of fibers in more logical order, and a separation of filament properties from staple properties where significant differences occur. The leader of the synthetic or man-made fibers is rayon. To industrial users rayon, like other synthetics, offers two primary advantages. First, being scientifically manufactured, its uniformity may be precisely controlled a t all stages of production, and second, its cost is relatively stable with prospects for eventual decreases as production grows. Today rayon staple fiber has limited industrial uses. The greatest industrial development was perfection of high tenacity, continuous filament rayon, which is of special value for fabric-reinforced mechanical rubber products. Approximately 500,000,000 pounds of rayon filament yarn were consumed in this field. Another cellulose-based fiber is acetate. Like rayon it is widely used in filament and staple form for consumer products. Of special interest in the electrical field, acetate’s dielectric strength is high. Even more significant is a high tenacity filament yarn, Fortisan, developed from acetate. The exceptional tensile strength and stretch resistance of Fortisan makes it useful for military applications such as flare parachutes, varnished insulation, and rubber and plastic combinations. However, it has low abrasion resistance and is quite expensive. A new rayon fiber for the tire cord has been described (67). A new type of high alpha cellulose makes possible the commercial production of “all-skin” rayon fiber allowing high stretch spinning techniques and permitting production of high tenacity rayon yarn, for tire cord, with strengths superior to those in current use, and staple fiber and yarn for viscose rayon fabrics with characteristics far surpassing those of today. Bass ( 8 ) has described the use of Super-Cordura in longer lasting rayon tires. This rayon yarn has uniform smooth filaments which in cross section are predominantly skin. They have an increased resistance to moisture, which is reflected in greater resistance to tire failure due to exposure of cords to moisture and easier drying in tire-building operations. Illingsworth (40) in reviewing the impact of man-made fibers on the rubber industry states that the day of the universal use of the natural fiber, cotton, for the wide ramifications of the rubber
2080
INDUSTRIAL A N D E N G I N E E R I N G C H E M K S T R Y
industry is past and very unlikely to return again. PITature, in designing the cotton hair, certainly did not consider the question of using this fiber as tire casing materials, and the advent of the man-made fibers has opened up vast possibilities that have hardly been explored. The synthetic fibers, nylon and Terylene, are likely to increase in importance. High tenacity nylon and Terylene have a much higher tensile strength than the industrial rayon yarns. Sylon has already established itself as a very good material for tire casings, and Terylene is now being evaluated in various composite products. The use of these two materials will be limited by economic considerations and the supply positions. The total production of nylon and Terylene at present Tvould be totally inadequate for the tire industry alone, and the use of the fibers will be limited to special applications where the high price of the material is justified by the superior performance of the synthetic fibers. Rayon will maintain its pobition for some years to come, The present standard high tenacity yarns are being replaced by rayons of approximately 2561, greater tensile strength. Nylon, in both staple and filament form, has several important industrial properties. T'ery high tenacity in both dry and wet conditions, excellent resistance to abrasion in flexing, toughness and elasticity, resistance to heat and many chemicals, and excellent electrical qualities. It has impoi tant military and industrial applications in parachutes, body armor, bridge pontoons, hose and belting, filter cloths, nets, insulation, plastic laminate, high tenacity tire cord, and many other uses. h'ylon (26%) in cotton blends improves fabric resistance 100% (60). Hotte (18) states that h'ylon, T - q e 6, has s h o m 20% more resistance to abrasion than Nylon, Type 66. A41thoughthe two types have similar chemical and physical properties Type 6 has a greater affinity for dyestuffs than Type 66. A a/,-ton Perlon (Type 6 Nylon) rolling mill strap, 126 feet long by 3 feet 7 inches wide and '/z inch thick has been installed (19). Perlon hoist cables are being tried in the mining industry; their weight is one half the weight of steel cables in current use. Of unusual interest, particularly in engineering problems involving electrical conditions, or the handling of strong acids, are the acrylic fibers that are among the newest of the true synthetics. Having low moieture absorption, dimensionally stable acrylic fibers are nonconductors of electricity and show good resistance t o many chemicals and destructive organisms. Orlon is light, strong, and resilient. It has outstanding resistance to ultraviolet rags, atmospheric effects, mildew, and bacteria, and thus, qualifies for many outdoor uses. Heat and chemical resistance suit Orlon for filter fabrics used under difficult filtering conditions; and, its bonding properties permit easy combination with rubber and plastic. Dynel, a staple fiber of vinyl and acrylic origin, in addition to its other properties, will not support combustion. This resilient fiber, while somewhat sensitive to heat, resists Etrong alkalies as well as acids, and is suitable for chemical resistant work clothing, filter cloth, insulation, hosiery dye nets, and other uses. Acrilan, another new acrylic fiber in staple form, has good resilience, high strength, and low stretch. I t dries quickly and resists mildew and many chemicals. X-51, available in staple and filament form, is notable for resilience, strength, and resistance to mildew and sunlight. Dacron, a new polyester fiber, is water repellent, dimensionally stable, and a good dielectric. Since it has good strength, flex life, shape retention, and resistance to abrasion, heat, and many chemicals, it shows promise for safety footwear and clothing, plastic laminates, and rubberized products. Saran is the generic name for a thernioplastic vinyl fiber characterized by toughness, flexibility, and resistance to chemicals, fire, and water. Vicara, a Roollike protein staple fiber with considerable heat and chemical resistance but poor strength, i s widely used as a blending fiber in apparel fabrics. Its industrial possibilities are limited, therefore. An interesting inorganic product is fibrous glass, such as Fiber-
Vol. 46,No. 10
glas, in both filament and staple form. Fibrous glass is incombustible, durable, and nonabsorbent with high tensile strength and resistance to weathering, heat, and many chemicals. Glassbased textiles have a higher electrical insulating resistance than do most other fabrics, particularly in high humidity applications, They are used in electrical installations, reinforced plastics, heat insulation, and filter cloths. Goldsmith (52) discusses the fact that a bigger glass fabric output opens the door to new uses. Glass textile yarn has the highest strength-weight ratio of any known textile fiber, but has very low knot and abrasion strength, necessitating special handling in all manufacturing operations. Some of the more significant developments are: 1. Glass laminates for automobile bodies 2. Air frames completely constructed of heat resistant and light but strong glass laminates 3. Glass fiber laminate hulls for small boats as well as large barges 4. Resin coated glass screening cloth 5. Decorative fabrics such as upholstery and curtains 6. Glass tape for electrical insulation 7. Parallel strand reinforcements for other film materials, such as plastic industrial tape. hIonsanto (61) states that polyester glass fiber laminates are fast becoming another basic material for manufacturing. The powerful reasons behind this rapid forging ahead of a relatively new material are: 1. Polyester glass fiber laminates offer a unique combination of properties. 2. Polyester glass fiher products of immense size can be produced by a new method of production, low pressure lamination, which requires only low pressures, little heat, and a relatively low capital investment for equipment. 3. Polyester glass fiber laminates with their ability to make large moldings in one piece open the doors t o an almost limitless list of new products. This particular brochure describes the production of the polyester glaes laminat,e. Modern Plastics (5.5) describes the production and properties of Chevrolet sports cars made with reinforced plastic bodies. These bodies are designed and constructed of reinforced plastic laminates resulting in lighter bodies. From a manufacturing standpoint Chevrolet cites both advantages and disadvantages for the reinforced plastics body. The low weight of the material promotes ease in material handling and the body sections are not readily subject to damage in transporting and assembling. The forming of plastics does not require heavy stamping presses. The quick molding of parts affords a short cut in primary design processes. However, the fabrication of plastic bodies now requires more labor and greater floor area than steel bodies. Recent developments indicate promise of eventually fitting manufactuie t o assembly line system that is a real key t o production efficiency. It has been estimated that the use of polyester resins in the reinforced plastics industry in 1954 nil1 jump to 35,000,000 pounds, compared to 26,000,000 in 1953, and 19,000,000 in 1952. The reinforced plastics division also uses phenolics, melamines, silicones, epoxys, alkyds, cellulosics, and vinyls. In the polyesters, fibrous glass is the main reinforcement, but with the other plastics cotton, rayon, nylon, paper, and the new synthetic fibera are used, I n order to fully utilize the reinforced plastics, continued research of chemical and mechanical engineering levels should produce new results. Gregg (53) describes the production of Fiberglas for air-drop containers, On a weight-t,o-strength basis these containers are stronger than steel and can t.alre from 1000 to 2000 drops. Fibres (66) discusses the working of modern fibrous material and outlines briefly the methods likely to give the most satisfactory result in such mechanical and manual operations as cutting, threading, drilling, milling, sawing, bending, forming, punching, and filing. The Asbestos Textile 1nstitut.e ( f ) has prepared a handbook devoted to the minernl asbestos fiber. It covere a description of
October 1954
INDUSTRIAL AND ENGINEERING CHEMISTRY
the products and their application and points out such advantages as incombustibility, high tensile strength, resistance to rot and decay, thermal stability, and other properties that are inherent in the inorganic asbestos fibers of which it is made. It lists representative uses and information on asbestos produsts. Fibres (26)describes a new heatproof fiber developed by research engineers of the Carborundum Co. that can stand a temperature of 2300’ F. without loss of properties and does not soften until subjected t o a temperature of approximately 3000’ F. Made of aluminum oxide and silicon carbide, a t present it is available only in a fluffy cottonlike bulk form. Extremely fine with a diameter of only 4 microns, which compares with 18 microns for silk, and 100 microns for human hair, it can be used as a superfilter or as a base for entirely new types of insulation in fireproof and electrical papers. Studies indicate that it may be suitable for heavy-duty brake linings, as a strength giving component in plastic laminates and high temperature gaskets, and as a flame filter to remove ash in gas turbines. Brooks ( 6 ) states that in 1954 the use of metallic yarns will extend t o buch fields as automotive fabrics, men’s apparel fabrics for suitings, shirtings, and knitted goods. Other new markets where increased use will be seen include the floor coveringindustry, plastics in which metallic yarns are imbedded for decorative quality, footwear, and decorative packaging material. From the standpoint of production, the ability to turn out a workable, nontarnishing, washable, metallic yarn is definitely established. One manufacturer (37) reports that spun fiber nylon filtration cloth is superior to continuous filament cloth because fuzzy fiber ends made solids removal easier. Kane (48) discusses microfiltration with a resin-impregnated wool filter. In selection of filtration media the engineer must consider these important factors: 1. Maximum allowable percentage of suspended solids in the filtrate 2. Physical characteristics of the suspended solids to be removed--lee., size, shape and nature 3. Amount of material to be removed He describes the preparation and tests on a graded density cartridge made up of woolen fibrous impregnated media. NONWOVEN FABRICS
Dwyer (dS) estimates that over 1000 different kinds of felt are bought by over 100 industries. Felt is very important to industry, because it is available in many densities, thicknesses, and qualities and is easily designed into products. I t cuts without fraying and can be die-cut, punched, skived, turned, molded, or otherwise simply processed. It has a high degreeof resiliency, an unusual high breaking strength, and an excellent coefficient of friction against wood, glass, or metal. Also, it is unaffected by normal atmospheric conditions, moisture, sun, heat, and cold, High capillary value for excellent wicking and filtering is one of its virtues. Felt dampens machine vibration and deadens noise effectively, and can be strongly cemented or bonded to other surfaces. Felt bobs and wheels in the full range of densities and hardnesses are aiding industry by making possible precision finishing, grinding, polishing, and buffing operations in the metal industries. Felt for such purposes must be specially engineered for the intended use. Aside from the important property of elasticity, felt can be coated with abrasive powder designed to do a specific finishing or polishing job. Maus (54)has described the use of nonwoven fabrics for hard-tofill jobs. Constant development of new types of nonwovens, new uses for them, and new methods of producing them, has kept the nonwoven fabric field in a flourishing condition. Industry uses nonwovens for filtration, decoration, packaging, and pattern making. As backing, lining, reinforcement, or padding, they appear in many products in the apparel, upholstery, automotive, and leather, or leather-substitute fields. They are used as insulation, as surface sheets, as containers, and as protective coatings.
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Larose (4?) studied compressibility of pile fabrics and reports on the relationship of thickness to pressure, using a modified form of equationa previously developed. COATED FABRICS
Johnson (41) discusses how new uses for vinyl and vinyl-coated materials have helped to expand the sales volume of plastic fabrics in the past year. Radical development has been seen during this time in the vinyl-coated fabric sheeting industry as manufacturers concentrate on satisfying a t one and the same time the consumer’s primary interest in appearance and the manufacturer’s concern with maximum performance. Different formulations of vinyl in the case of coated fabrics with different types and weights of textiles are employed to achieve special combinations of such qualities as scuff-resistance, resistance to oils and greases, flexibility over a wide temperature range, and high impact strength. Cotton-picker bags have been given new life when coated with Goodrich’s Geon vinyl plastic. A vinyl sponge plastisol has been developed for use as a laminate to fabric for rug padding and underlays and many other forms. The material will not rot or stain and is virtually odorless, according to the WatsonStandard Co. (16). The Scandinavia Belting Co. (68) has developed a vinyl chloride polymer in combination with a textile base belting that retains the strength imparted by the solid woven cotton base and that has high corrosion resistant qualities. This solid woven base is a multi-ply belt, where piles are actually interwoven and have no dependence on the adhesive qualities of the covering material. The coating makes the belting immune to stretch, shrinkage, and deterioration from prolonged exposure to con&tions of service that are alternately wet and dry. SYNTHETIC FIBERS MANUFACTURE
Hill (39) in his recent book describes the present state of knowledge of the comparatively new chemistry of the so-called high polymers as applied to the synthetic fibers industry. Chapters are included on the kinetics and energetics of polymerization reactions, on vinyl polymers, polyamides, polyesters, and polyurethanes, and on miscellaneous fiber-forming condensation polymers. Work is included also on conversion of the polymers into fibers by solubility, melt extrusion, wet and dry spinning processing. Hall (34-36) has discussed chemicals for use in synthetic fiber manufacture. The discovery and present day manufacture of synethetic fibers is of outstanding interest to organic chemists in that all these fibers are made from chemicals that have only in recent years become available in commercial quantities and a t reasonable prices. With few exceptions, none of these fibers could have been manufactured on the large scale 20 years ago, since the necessary chemicals were then either unknown or only available in small amounts. The manufacture of adipic acid and hexamethylenediamine, components of nylon, had to be tackled before the actual spinning of nylon could be commenced; the production of Orlon has only become possible on a large scale by the recent discovery of new methods for manufacturing acrylonitrile cheaply, Thus synthetic fibers are creating an entirely new synthetic chemical industry that now appears to be capable of almost infinite expansion. He describes chemicals needed for manufacturing nylon and others such as polyacrylonitrile, used for the production of Orlon and other fibers; polyvinylchloride is used in some French synthetic fibers, vinylidine chloride for saran and Velon, vinyl acetate, and polyethylene. He also describes the production of caprolactam, which is used for the production of Perlon L. He reviews the production of the chemicals needed for Terylene and Perlon U. For Terylene, ethylene glycol and dimethylterephthalate are needed. Perlon U requires sources of hexamethylene diisocyanate and tetramethylene glycol. Shapiro (89) has reviewed the fundamental principles of emul-
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sion polymerization, tracing the effect of many variables including copolymer composit’ion, emulsifying system, particle size, effect of these factors on molecular weight, chemical stability, mechanical stability, gloss, and washability. He discussed also the applications, ranging from emulsifying agents and warp sizings to finishing agents, pigment binders, and nonwoven fabrics, Wormell (76) has described the manufacturing techniques and production of milk casein and peanut protein fibers. Ardil, peanut protein fiber (31, is a ne17 manufacturer’s staple fiber, which can be blended with other fibers to give the resulting fabrics a soft, smooth handle, warmth, drape, and crease resistance. ?roperties and blending characteristics are discussed. Cheshire (11) points out the necessity for new developments on protein fiber. He mentions that under suitable conditions wool may be converted into a finer and stronger fiber with quite distinct and desirable characteristics. Koch (46) has described the producers, the history, the methods of manufacture, the chemical and physical properties of Fibrolane, Merinova, and Caslen, all of which are regenerated fibers produced from casein, the phosphoprotein of milk. The British Rayon &: Silk Journal ( 4 ) has described developments in man-made fiber production and processing technology in 1953. Much of the emphasis is on the polymer in relation to fiber properties. Whinfield (75) describes the development in Great Britain of the synthetic fiber knox-n as Terylene, which is manufactured in this country under the name Dacron. He shows its development through the three phases, laborat,ory, pilot plants, and large scale manufacturing. Modern Textiles ( 6 6 ) lists the types of rayon acetate and synthetic yarns and fibers that are produced in this country, together with t,he manufacturer. FIBER FINISHES
? a p e and Smith (6.8) in their discussion of silicone chemical applications in textile processes mention the use of silica sols on textiles to increase interfiber friction and aid in spinning, Silica sols have also found a number of import.ant applications in the finishing of fabrics to prevent slippage of yarn. They are used as antisnag treat,ments of nylon hosiery. They increase the strength and abrasion resistance of cotton and woolen fabrics. Water repellency may be achieved by use of certain of the silicone oils or esters. Organic silicates have been used as foam suppressers during cert’ain dyeing operat,ions. Wool is rendered nonfelting and shrink resistant when treated with phenolt,richlorosilane. I n tmhereinforced plastic industry, silicone resins are used to act as a size in giving improved adhesion between t,he fiber glass and the resin. Phenolmethylpolysilosanes may also be used for varnishing glass fabric, and mixtures of resinous and oily organosilicone polymers, when applied to glass fiber strands and yarns, confer increased strength and resistance to abrasion and flexing. Krammes and Pllaresh (46) have discussed the ident’ification of the various textile finishes. A wide variety of new finishing agents is now available. -4s a consequence, the textile industry is now producing durable finishes and attaining such properties a8 shrinkage control, wat,er repellency, spot and wrinkle resistance, and fire retardancy. Widespread use of the newer finishing agents has brought with it the problem of identificat,ion. The authors present a method t’hat is flexible, including solvent action, staining and spotting reactions, as well as other physical methods. Detrick ( $ 1 ) discusses t’he value of chemicals in adding that finishing touch to textile fabrics. He states that t.he textile industry, in the United States alone, in 1952 produced over 12 billion yards of broad woven fabric. While great strides have been made in the mechanical processing of fibere to fabrics, ut’ilization of chemicals to produce textiles of improved physical properties and sale appeal has lagged. Fiber lubricants and softeners are important. Starches, gums, and natural resins find large scale use in yarn sizing, print,ing, and stiffening. Chemicals
Vol. 46, No. 10
are needed to prepare the fibers and fabrics for dyeing and printing, as it is color that often attracts the buyer. Chemicals are used to make fabrics water-repellent, fungus-proof, mothproof, fire-retardant, and shrinkproof. Products which will bind water and hold it a t low humidity are a boon to the synthetic fiber manufacturer as antistatic agents. Chemicals are used to give the consumer a more attractive and durable fabric. Attractive colors plus the chemical modification of natural fibers and the synthesis of new fibers offer a solution so that the textile industry can obtain a fair share of the consumer dollar. IDENTIFICATION OF FIBERS
Luniak (48)has provided in a recent book, “The Identification of Textile Fibers,” clear instructions for carrying out fiber analyses, including a fiber atlas of 312 photomicrographs. The most important aid for identification is still the microscope, although a number of chemicaI reagents have been specially developed for work on analyses, which give typical reactions for various fibers. A new method for proving the presence of polyacrylonitrile fiber has been developed based on the fact that these fibers, when placed in concentrated sulfuric acids, split off prussic acid. The latter, with cupric sulfate, or other copper salt&,yields cupric cyanide and an oxidizing agent that will oxidizefor example diethylamineand show a blue color. Reif (66) describes identification procedures for Orlon, nylon, and Perlon based upon solvent action. Lundegard and Roseberry (49) have described easy, accurate, and reproducible procedures for identification of the synthetic fibers; nylon, Dacron, Orlon, Acrilan, X-51, Dynel, saran, and polyethylene. Identification is accomplished by: 1. The test for detecting chlorine 2. The flame test 3. The reaction to chemical compounds The microscopic tests a. The use of an identification dye
4.
Results of these tests are presented and summarized in tables showing the effect of heat and concentration of the chemical reactions, the longitudinal and cross-sectional appearances of the fibers, the colors produced by the identification dyes, and the odors, residue, and behavior of the fibers when subjected to a flame. Koch (44)describes a comprehensive method of identifying and differentiating between the chemical fibers. Identification is best carried out by using a microscope or by means of chemical or color reaction. Identification by other characteristics such as specific gravity, smelling phenomena, thermal behavior, melting point, detection of certain elements or compounds, luminescence, and behavior on burning, is either too complicated or lws reliable. FLBKMABLE FABRICS ACT
Buck (8) discusses the Flammable Fabrics Act that went into effect in July of this year. This act affects everyone who markets or handles fabrics finished for clothing use, or anyone who makea articles of wearing apparel directly from yarn. One can market or handle a highly flammable fabric if:
1. 2. 3. 4.
I t is intended for nonclothing use It is being shipped for fire-retardant finishing It will be processed into exempt clothing items I t goes into covered or unexposed parts of garments
While the act covers only clothing materials in general, industrial manufacturers should carefully consider the effects on their production of fabrics which might be exposed to flammable condition. LITERATURE CITED
(1) Asbestos Textile Institute, “Handbook of Asbestos Textiles,” Bulletin, February, 1954. (2) Bass, K. C., Modern Teztiles Mag., 34, No. 8 , 31 (1963).
October 1954
INDUSTRIAL AND ENGINEERING CHEMISTRY
(3) B r i t . R a y o n & Silk J., 30, No. 58 (1953). (4) Ibid., 30, No. 356, 52 (1954). (5) Broocks, Arthur C., D a i l y N e w s Record, p. 29 (Feb. 11, 1954). (6) Buchanan, Andrew E., Jr., Fibres (Natural and Synthetic). 14, No. 9, 327 (1953). (7) Buck, George S.,Jr., Papers Am. Assoc. Textile Tech., 9, No. 1, 9 (1953). (8) Ibid., Textile Inds., 118, No. 15, Supplement (1954). (9) Buras, E. M., Cooper, A. S., Keating, E. J., and Goldthwait, C. F., Am. Dyestuff Reptr., 43, No. 7, 203 (1954). (10) Chace, Wm. N., D a i l y N e w s Record, p. 1, Sect. 2 (Feb. 11, 1954). (11) Cheshire, 9.F., Brit.R a y o n & Silk J., 30, No. 352, 76 (1953). (12) Compton, Jack, Am. Dyestuff Reptr., 43, No. 4, 103 (1954). (13) Compton, Jack, Martin, W. H., and associates, TextileInds., 117, NO.10, 138-A (1953). (14) D a i l y N e w s Record, p. 25 (Oct. 29, 1953). (15) Ibid., p 21, Sect. 1 (March 18, 1954). (16) Ibid., p. 30 (May 12, 1954). (17) Ibid., p. 26 (May 24, 1954). (18) Ibid., p. 22 (May 26, 1954). (19) Ibid., p. 24 (May 27, 1954). (20) Descheemaeker, A., Teztile World. 104, No. 5, 100 (1954). (21) Detrick, S.R., Dailz! N e w s Record, p. 16, Sect. 2 (Jan. 21 1954). (22) Dillon, John H., Tertile Research J., 23, No. 5, 298 (1953). (23) Dwyer, R. V., Daily N e w s Record, p. 17, Sect. 1 (Jan. 21, 1954). (24) Ellsworth, Robt. E., Modern Teztile Mag., 34, No. 9, 32 (1953). (25) Fibres (Natural and Synthetic), 14, No. 10, 350 (1953). (26) Ibid., No. 12, p. 411. (27) Filtration Engineers, Inc , Filtration Fabrics Div., Newark, N.J., Bull. “Nylon Filter Cloth.” (28) Freedman, E., Papers Am. Assoc. Textile Tech., 9, No. 255 (1954). (29) Goldberg, J. B., Textile Forum, No. 1, 25 (1954). (30) Goldberg, J. B., Papers Am. Assoc. Textile Tech., 9, No. 266 (1954). (31) Goldberg, J. B., Tertile A g e , 18, 22 (1954). (32) Goldsmith, J. J., Daily N e w s Record, p. 26, Sect. 2 (Feb. 11, 1954). (33) Gregg, Charles, Ibid., p. 30 (April 29, 1954). (34) Hall, A. J., Fibres (Natural and Synthetic), 14, No. 9,303 (1954). (35) Ibid., No. 10, p. 343. (36) Ibid., No. 11, p. 393. (37) Hamlin. Marv. J . Textile Inst.. 44. No. 11. 745 (1953). i38j Hansen, E. C:, and Bergman, C. A., Am. DyestubReptr., 42, No. 15, 466 (1953). (39) Hill, Rowland, “Fibres from Synthetic Polymers,” Elsevier, London, 1953. (40) Illingsworth, B. J. W., Rubber A g e , 73, No. 45, 657 (1953). (41) Johnson, P. F., D a i l y N e w s Record, p. 16, Sect. 1 (Jan. 21, 1954). (42) Kane, E. D., IND.ENG.CHEX, 45, 860 (1953).
(43) (44) (45) (46)
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Kester, Gordon H., D u Pont M a g . , 47, No. 5, 1 (1953). Koch, Paul A., Modern Textiles Mag., 35, No. 1, 36 (1954). Ibid., No. 4, p. 71. Krammes, Ray, and Maresh, Charles, Am. Dyestuff Reptr., 42, No. 11,317 (1953). (47) Larose, P., Textile Research J., 23, No. 10, 730 (1953). (48) Luniak, Bruno, “Identification of Textile Fibres,” Pitman, London. 1953. (49) Lundegard, M., and Roseberry, E. D., Am. D y e s t u f Reptr., 43, No. 4, 93 (1954). (50) McNamara, T. P., Teztile Forum, 1954, p. 20. (51) “Man-Made Fibers Handbook,” Rayon Publishing Co., New York, 1953. (52) Martin, J. L., D a i l y N e w s Record, p. 2, Sect. 2 (Feb. 11, 1954). (53) Mauersberaer, H. R., “Matthews’ Textile Fibers,” 6th ed.. John Wiley, New York, 1954. (54) Maus, R. G., D a i l y N e w s Record, p. 48, Sect. 2 (Jan. 21, 1954). (55) Modern Plastics, 31, No. 4, 83 (1953). (56) Modern Textiles Mag., 34, No. 9, lOOA (1953). (57) Ibid., No. 10, p. 31. (58) Ibid., 35, No. 3, 8 (1954). (59) Moisson, G. M., Textile W o r l d , 103, No. 9, 109 (1953). (60) Moncrieff, R. W., “Artificial Fibers,” John Wiley, New York, 1954. (61) Monsanto Chemical Co., New York or Cleveland, “A Sketch Glass Fiber LamBook of Profitable Products-Polyester inates,” Brochure, 1953. (62) Payne, J., and Smith, E., Brit. Rayon & Silk J., 30, No. 353,Ql (1953). (63) Pranal, L., J . Teztile Inst., 45, No. 4, 125 (1954). (64) Quig, J. B., Teztile Research J., 23, No. 5, 280 (1953). (65) Reeves, W. A., McMillan, 0. J., Jr., and Guthrie, J. D., Teztile Research J., 23, No. 8, 527 (1953). (66) Reif, W., Melliand Teztilber., 34, No. 3, 219 (1953). (67) Rutledge, C. H., D a i l y N e w s Record, p. 52, Sect. 2 (Jan. 21, 1954). (68) Scandinavia Belting Co., Newark, K.Y . . Brochure, 1954. (69) Shapiro, L., Am. D u e s t u f Reptr., 43, No. 5, 132 (1954). (70) Smith, L., Ibid., 42, 789 (1953). (71) Somers, J. A,, Brit. R a y o n & Silk J . , 30, No. 350, 52 (1953). (72) Ibid., No. 354, 62. (73) Stoll, R. G., “End-Use Requirements versus Material Properties of Textiles,” Research and Development Report, Textile Series, Report No. 83, U. S. Dept. of Commerce, Office of Technical Services, Washington 25, D. C. (74) Wellington-Sears Co., New York, N. Y . , “Modern Textiles for Industry,” Brochure, 1952. (75) Whinfield. J. R., Teztile Research J., 23, No. 5, 289 (1953). (76) Wormell, R. L., J . Textile Inst., 44, No. 7, 258 (1953). (77) Yeager, C. C., Textile W o r l d , 103, No. 7, 137 (1953).
