Journal of the American Association of Textile Chemists and Colorists November 18, 1970/ Vol. 2, No. 23 (XX)

MeetingThe Challengesof the TextileIndustry ThroughApplicationResearchandTechnology

By PAUL L. MEUNIER, The Du Pont Co., Wilmington, Delaware

duction was 3,630 million pounds. I Ntextilespeakingindustry,of challengesI refer toofthosethe Although the differences in pounds occasions when the industry has been of wool and cotton are rela- confronted with serious problems tively small, the percentage change brought on by war, depression, new from 1939 to 1969 is revealing. discoveries and the like. Needless to Thirty-one years ago, cotton produc- say, it has accepted these challenges tion in the U.S. was 80.1 % of the and continues to advance along with total whereas in 1969 it was 41.3 %. other industries in our "exploding" Wool fell from 8.8% to 3.7% and silk technical age. from 1.0 % to 0.03 %. On the other How has this been accomplished? hand, man-made fibers increased from By applying the fruits of research and 10.1 % of total production in 1939 to technology! Whatever one's position 50.0% in 1969! Meanwhile, total fiber ABSTRACT might be on the question as to whether production more than doubled during Research and technology have produced our industry, particularly the dyeing this span. some remarkable improvements in dye- and finishing part of it, is as pro- This picture serves to illustrate the ing and finishing in a relatively short gressive as it should be, the fact re- nature of changes that have been tak- time. The author, the 1970 recipient mains that remarkable improvements of AATCC's Olney Medal for outstanding ing place in the last few decades and achievement in textile chemistry, have been made in a relatively short the need for the industry to keep traces several of the more notable time. pace with advancing technology. I will advances and offers some recommenda- U.S. mill production of man-made discuss a few notable developments tions for future growth. ~ibers - polyester, nylon, acrylic, in the dyeing and finishing field and rayon and acetate - in 1969 totaled then offer some recommendations for KEY WORD INDEX 4,740 million pounds. Cotton mill future growth. Carriers production was 3,925 million pounds, Dyeing wool was 355 million and silk was Dyeing Of Cotton Piece Goods Fibers 3 million pounds in 1969. In con- With Vat Dyes Finishing Padding trast to this, for the year 1939, man- Traditionally, the best quality dye. Research made fiber production was only 459 ing on any type of cotton fabric was Steaming million pounds, silk was 47 million, obtained with vat dyes by padding, wool was 397 million and cotton pro- drying and jig development with caus.

386/21 MeetingThe Challenges Machine (6), utiliing molten metal ton, rayon or wool were very for the development of the dyes, was poor on nylon. brought out in England. Nevertheless, broadwoven and knit The success of the pad-steam pro- fabrics, as well as hosiery and yarns of cess was based on the appreciation of a nylon, were dyed in the beginning and simple scientific fact - that the rate are still being dyed with disperse or tic soda and sodium hydrosulfite. This of reaction increases by about 100 % acid dyes, depending upon end-use re- is a batch process in which an average for every IOC rise in temperature. quirements. Demand for the superior load of 500-1,000 yards can be dyed Thus, when vat dyes in their pigment wash and lightfastness of acid type and finished in about three to four form and caustic and hydrosulfite are dyes is increasing because of wide- hours. This so-called pad-jig process brought together in a steam atmo- spread use of nylon in automotive up- was originally developed during the sphere, reduction and fixation of the holstery, carpeting and outerwear fab- first decade of this century (1). dye in the cotton fiber occurs rics. The goal in the coloration of all instantaneously. Another vital consid- textile materials is the production of a eration was that the stability of hy- Meeting A Need full range of attractive shades with drosulfite in a steam atmosphere Here is one example of the tole of maximum durability. In the U.S., without air is remarkably good. At research and technology in supplying there had been a strong demand for speeds of about 100 yards per minute a need during World War II. It will a continuous process to satisfy large each pad-steam range can produce the serve to demonstrate the type of co- volume production of goods at lower equivalent. of about 24 jigs in a given operation between research groups and costs. During the 1920's and 1930's, period of time. industry that is needed to meet our partial success was attained by two challenges. The U.S. Armed Forces continuous methods known as the re- DyeingOf SyntheticFibers had designed a jungle boot for combat duced pad-booster (2) and the pig- I shall define synthetic fibers as soldiers fighting in the tropical areas ment-pad-booster (3) systems which those manufactured from man-made of the Pacific. The boot consisted of a produced acceptable dyeings on cer- intermediates. This excludes the man- spun nylon fabric bonded to the rub- tain types of unmercerized goods for made fibers derived from natural ber sole. Substantial yardages of the work clothing and other limited uses. sources such as cellulose acetate, rayon nylon fabric, dyed in an Olive Drab In the 1940's, however, projected re- (regenerated cellulose) and nitro- #7 shade, were needed quickly for quirements of the U.S. military for cellulose. mass production of the boot. The War vat-dyed combat uniforms were so The first truly synthetic fiber was Production Board established a com- great that research efforts were re- nylon, invented by Carothers and in- mittee composed of industry repre- newed and intensified. The pad-steam troduced as a textile fiber in 1938. The sentatives from chemical manufactur- continuous dyeing process (4), intro- impact of this fiber and those that ing and dyeing and finishing groups to duced in 1944, proved to be the followed closely on its heels (i.e., study the problem. As a result, several answer to that particular challenge. It 'acrylic, polyester, spandex, olefin, successful processes were developed is still used worldwide for high quality etc.) on the textile industry and the for continuously dyeing the spun nylon dyeings on cotton and blends of cotton whole economy in general has been fabric with acid and chrome dyes and with synthetic fibers. At the same tremendous. The textile industry has the needs of the Armed Forces were time, in the 1940's, the Williams Unit never been so dynamic as during these suppiled (7). (5) was introduced. This provided a last three decades. Evidence of this is One of the processes consisted of short volume development chamber seen in the drastic changes which have padding nylon fabric with a solution for economical dyeing of certain types occurred in the fiber content of wear- containing dyes and a highly effective of fabrics. Later on, the Standfast ing apparel, floor covering, upholstery dispersing and wetting agent, followed fabrics and others. by steaming at atmospheric pressure Nylon filament yarn was first used for about ten minutes. We knew then - for hosiery. Then, during World that steaming under pressure at ele- War II, it was reserved chiefly for vated temperatures would have been PAULL. MEUNIER, military uses such as in parachutes, better because of time saving and im- the 1970 recipient ponchos and uniform fabrics. Nylon proved dye utilization, but suitable of AATCC's Olney staple fiber was employed in jungle equipment for pressure steaming was Medal, the associa- boot cloth. not available. The wonder chemical, tion's highest recog- nition for technical To the dyer and finisher, nylon rep- that is, the dispersing and wetting and scientific contri- resented new and somewhat perplex- agent, was - would you believe? butions to the ad- ing challenges. Although it possessed ammoniacal shellac! There has not vancement of textile affinity for nearly all classes of dyes, been anything before or since to sur- chemistry, is director their behavior on nylon was often pass it for nylon dyeing but, of course, of The Du Pont Coo's much different from that exhibited on dyes and chemicals we now have many good synthetic technical laboratory at Wilmington, Del. other fibers. For example: chemicals for this purpose. A native of Indianapolis, he holds a BS . Certain disperse dyes which had In dyeing nylon filament yarn or in organic chemistry from ,Butler Uni- excellent light fastness on cellulose fabric, irregularities are often ac- versity and MS and PhD degrees in or- acetate were very fugitive on ny- centuated, particularly by acid dyes, ganic chemistry from Pennsylvania State University. Since joining Du Pont as a lon; in the dyed fabric. These irregularities chemist in 1936, he has served in a wide . The washfastness of acid and di- may be of one or more of the follow- variety of assignments (TCC, Vol. 2, No. rect dyes On nylon was appreci- ing types: 14, July 15, 1970, pl0). His broad ex- ably better than on wool and cot- ( 1) Luster differences in yarn perience and knowledge in textile dyeing, ton; and which lead to streaky appearance, even printing and finishing have earned him wide acclaim in governmental, institu- . Certain vat dyes which exhibited when the yarn bundles are uniformly tional and commercial circles. very good lightfastness on cot- dyed.

22/387 0::0 Vol. 2, No. 23 (2) Physical variations in adjacent printing technology by studying the necessary basic information and prac- yarns of the fabric, such as might be effects of pressure steaming of padded tical processes for dyeing the first introduced during processing of yarn fabrics in autoclaves using varieties polyester fibers. Research teams ex- to fabrics. of assistants or potential swelling plored the chemistry of carriers and (3) Chemical differences typified agents. Also, a small, pressurized reel evaluated literally hundreds of com- by variations in the basicity of in- machine was built for dyeing from pounds as additives to the dyebath, dividual yarns. aqueous dyebaths at high tempera- pre-padded on the goods to be dyed or tures. Disperse dyes covel: both physical as pretreatments of the fabrics in so- and chemical irregularities because Finally, the day came when we called "standing baths." This work pre- ceded the announcement of Dacron they transfer readily during dyeing, gathered around a laboratory scale but luster differences can result in one-ppund package dyeing machine on by several years. It was evident streaky goods. On the other hand, at which our safety engineers had in- that carriers must be aromatic rather temperatures under the boil most acid stalled a pop-off valve set to go off if than aliphatic and to be highly effec- dyes migrate or transfer very little and the pressure exceeded 15 psi above tive they should have solubility in the not only fail to cover but actually ac- atmospheric pressure. The tempera- polyester fiber, thus being able to dis- centuate physical and chemical varia- ture at this pressure is 121C or 250F. rupt the ordered arrangement of fiber tions in conventional dyeing processes. To operate under pressure, we had molecule chains and allow dyes to simply closed off the expansion tank penetrate. Schuler and Remington Methods have been developed to or overflow kier. This first pressure (15) published one of the most widely improve the levelness of acid dye ap- dyeing experiment was a complete suc- recognized early papers on the plication to nylon through the use of: cess (12) not only because the dyeing mechanism of dyeing Dacron polyester elevated dyeing temperatures (8), swell- was good and the equipment did not fiber with disperse dyes. They showed ing agents, anionic dyeing assistants, rupture or blow up, but it gave us that the fiber is dyed by a reversible cationic dyeing assistants (9) and the confidence that commercial mill process involving solutwn of dye in development of new acid dyes having equipment, represented in this experi- good transfer properties (10). fiber. The dyes- are very slightly ment, would probably be operable. soluble in water and enter the fiber Just as nylon responded to scientific Later events proved this to be the from the solution in the aqueous dye- study and adoption of new techniques case. It is true that earlier workers at bath. Invaluable assistance and guid- to overcome serious commercial ob- Uxbridge Worsted Co. had demon- ance was given by industry people who stacles, so have the acrylics and strated the advantages of pressure participated in mill trials. Equipment polyesters. Complete lines of cationic dyeing of wool but they had built a modifications were made to increase and disperse dyes in powder, solution "submarine" to house a dye box or the effectiveness of carriers, e.g., the and paste forms have been developed. booster bath of conventional design insertion of top steam coils to main- For the acrylic fibers, cationic dye (13,14). tain high temperatures in becks and application is controlled by the use of By the time significant quantities of jigs. cationic or anionic retarding agents Orlon acrylic and Dacron polyester The huge market for carriers in (11). For the polyester fibers, carriers - fibers were available in the market, the this country alone is a strong indica- are used to improve the rate of dyeing industry had met several challenges, tion of the progress of the industry in of the disperse and cationic dyes. The namely: this field. Whereas assistants of vari- development of dyeing methods utiliz- ( 1) It had learned how conven- ous types had been employed previ- ing carriers is a separate story in itself tional becks and jigs could be covered ously in the dyeing and printing of and deserves special treatment else- tightly so that temperatures very close acetate, rayon, cotton and nylon, never where. In fact, the market for carriers to the boil, 208-21OF, could be ob- before had there been such de- used in these dyeing procedures is tained. Engineers learned how to pendence on specific organic chemi- large and very attractive. pump hot liquors without cavitation cals for carrier activity in dyebaths or in the lines, in printing pastes. New TechniquesOf Coloration (2) Carrier dyeing of polyester fibers was practiced widely, and PressureDyeing Now, I should like to beg your in- (3) Pressure dyeing was firmly es- dulgence while I reminisce that period tablished for dyeing yarns, sewing Of all the challenges to the so- of our recent history which is probably thread, raw stock and certain types of called "backward" dyeing and finish- the most important. These were the piece goods in beam machines. ing textile industry, that posed by the years just after World War II when need for pressure dyeing was perhaps the industry was trying to utilize to the most severe. On the other hand, it Not As Simple As It Sounds the fullest extent the nylon fibers re- is an excellent example of technical leased from military priorities. At the Lest we have the impression that progress and we should all feel proud same time, many of us were carrying such things just happen, let me assure to be part of it. out research on the dyeing of new you that they do not. For example, I have already described an incident fibers; e.g., the forerunners of Orlon many thought that an active boiling in one of the first applications of pres- and Dacron. We were convinced that bath meant that its temperature must sure dyeing. Economical and technical ( 1) all the new synthetic fibers re- be at or near the boil. In equipment advantages of pressure dyeing were quired the highest possible temperature open or partially open to the atmo- pointed out soon after polyester and for reasonable diffusion rates of dyes sphere, however, heat losses from con- acrylic fibers appeared on the mar" into fiber, (2) dyeing at elevated vection and radiation are so great that ket. As the volume of these new temperatures under pressure was a the temperature of the liquor was of- fibers increased, the demand for pres- "must" under certain conditions, and ten found to be as low as 180-190F. sure equipment and processes in- (3) other means of "opening-up" these Carrier dyeing sounds simple, too, creased also. Adaptation of existing intractable fibers must be found. In but intensified application research ef- circulating machines to pressure dye- these studies, we borrowed from textile fort was expended in developing the ing was accomplished quickly and new

November 18, 1970 ceo 388/23 MeetingThe Challenges new, level dyeing acid colors and im- studies were needed to bring about the proved leveling agents at the boil (10). final marriage of the two processes in the smooth running operations that The Thermosol Process we all know today. This was a joint equipment was also designed for raw- effort of the dyeing and finishing in- In the search for other means of stock, yarns and hosiery. Also, the dustry and dyes and chemicals manu- Burlington beam machine was rede- "opening up" the new synthetic fibers facturers. Among the problems solved signed for pressure to dye light and so that dyes could penetrate readily, and needs met in this enterprise were medium weight fabrics at elevated we discovered the thermosol process the following: temperatures. It has been widely used (16). The principle is very simple. (1) Speck-free vat dye pastes and for dyeing polyester/wool suitings as Nonionic dyes - a grouping that in- disperse dye pastes. well as nylon and nylon/wool ski- cludes disperse dyes, vat dye pigments, (2) Techniques for controlling mi- wear fabrics. azoic pigments, or any other coloring gration through the use of pad bath The Barotor, an ingenious idea for matter without pronounced ionic additives and infrared predrying. handling light weight, delicate fabrics properties - can penetrate and dye (3) Development of new disperse without tension and dyeing at high any thermoplastic fiber in which they dyes having high resistance to sublima- temperatures under pressure, was an- are soluble. For example, in addition tion. nounced in 1952. While it produced to the most widely known application (4 ) Chemical finishing, including excellent results, the expense of load- of disperse dyes on Dacron polyester durable press, water and oil-repellent ing and unloading on the movable bars fiber, the 2: 1 premetalized acid dyes finishes, etc. relegated the machine to operations can be dyed on nylon, special cationic At the latest count, there are about where it was used solely to correct dyes on Orlon acrylic fiber and soluble 70 completely continuous thermo sol- unlevel dye lots. No machine of this vat dyes which are leuco esters, can pad steam ranges in this country. Ad- type is in use today. be dyed on Dacron. Dyes are padded ditional semi-continuous arrangements Early in the 1960's, Burlington on the fabric which is then dried and involving the two basic elements of the Engineering introduced their low pres- exposed to a short heat treatment at a process are utilized. sure (LP) and high pressure (HP) temperature below the softening point becks. The LP machine, designed for of the fiber. On Dacron, using dis- Other Important Advances operation up to 220F, was recom- perse dyes, dyeing is complete in only While we have selected these few mended for fabrics of nylon, triace- 60 seconds in dry air, 10 seconds in areas of activity to illustrate the im- tate, acrylic fibers, wool and blends. contact with hot surfaces or about portance of research and technology The HP unit could be operated at 3 seconds in a very hot infrared to the progress of our industry, recog- temperatures up to 300F and used heating zone. The diffusion rates of nition must be given to other de- for polyester/wool, rayon or cotton dyes vary in the different substrates velopments, many of which are per- blends in a broad range of fabric such as nylon, polyester, acrylic; haps equally important. Some of these weights including knit goods. Al- also, dyes within any given group will are: though the investment is high, the vary in this respect. It was apparent, . Resin-bonded pigment printing and pressure beck is widely used. There however, that the process would be dyeing systems are approximately 290 pressure beck most useful for dyeing Dacron poly- . Flash-age printing of vat dyes on machines in the U.S. ester fiber because disperse dyes have drapery and slip cover fabrics Burlington Industries designed the a high degree of solubility in the fiber . New sulfur dyes, including the vat- pressure jet machine and Gaston and their wetfastness and lightfastness table types County is building it. Operating up to properties in general are very good on . Fiber-reactive dyes 300F, the pressure jet is based on the this fiber. Likewise, other colorants . Continuous dyeing processes for principle of introducing cloth in rope applied by the thermosol process, such wool rawstock in the scouring train form in a liquid stream enclosed in a as vat pigments and soluble vat dyes, and in special steamers pipe. The clotQ j~ propelled by a possess outstanding fastness properties. . Printing of synthetics by heat trans- specially, designed Venturi jet, deriv- In one sense, the thermosol process fer from paper ing liquid power from a circulating was developed and demonstrated com- . Continuous dyeing and printing of pump. Absence of moving parts makes mercially long before its time. The carpets it feasible to enclose the jet device in a early laboratory work was carried out . Continuous dyeing of polyester fab- pressure chamber. The rapid move- by Joseph Gibson (17) during the late rics and film from hot, non-aqueous ment of dye liquor in the overhead 1940's and mill trials were conducted solutions of dyes tube and the controlled movement of in 1949-1950 on fabrics of filament . Chelatable dyes for modified poly- cloth facilitate good dye distribution and spun Dacron and nylon. The real propylene through the goods and rapid, even challenge came later when fabric de- . Pad-steam continuous methods for dyeing. The pressure jet is immensely velopment and market studies of acrylic fiber tow and stock successful because it is used for dye- blends containing Dacron and cotton . Computer shade matching and in- ing polyester double knits. About 240 clearly showed that an economical, strumental measurement of color of these machines are in use in the continuous process for these blends . Polychromatic dyeing process U.S. was a "must" if Dacron was to pene- . Resin finishes for "wash-wear," Pressure jigs have also been de- trate the huge cotton market. durable press signed and built in Europe. They are The tools to accomplish this goal . Fluorochemical finishes for stain used for dyeing filament nylon and were available - the thermosol meth- resistance, oil and water repellency polyester fabrics. To my knowledge, od for dyeing the Dacron with dis- the pressure jig has had very limited perse dyes and the pad-steam process Many Challenges Remain application chiefly because of diffi- for dyeing the cotton portion of the The list is long but still incomplete. culty in sampling and competing pro- blend with vat dyes. Nevertheless, ap- There remain, however, several areas cesses have been developed, utilizing plication research and engineering where the challenges have been hurled,

24/389 (XX) Vol. 2, No. 23 and they are waiting for our answers. References R,po"", Vol. 47, 1958, pl83. (10) Tu,"a, G. R., N,wby, W. E. end Speck, The question of solvent dyeing, for (1) S'hkgd, U.s. P". 893,384. 1908; U.s. S. B.. Ama"an DY"'uff R,po,"" Vol. 56, instance, brings forth comments run- Pot. 1.121,295, 19f4. 1967, pm (P998). (2) Tk'. M. E., U.S. P,r. 1,652,649. 1927. (U) budu" J. F., Am"ican Dy""'!! R,- ning the gamut from "bullish" to (3) Wombk, G. F., U.s. P". 2,396,908, 1946. po,"" Vol. 42, 1953, p792. (4) Mounia, P. L., Ama',an Dye.>!u!! R,. (12) Lyl" C. G.. 1enn"00" J. J. ". end "bearish." Many organizations are po"a, Vol. 34, 1945. p206; Stott, P. H. ,nd Thomn, R. ,., Am,,',oo Dy"/uff R,po"", working on various aspects of solvent Shimp, R. A., U.s. P,r. 2,487,197, 1949. Vol. 40, 1951, p585. (5) Willi,m" S. R., U.S. P,t. 2,364,838, 1946. (f3) W,lt", R. J., U.S. P". 2,387,200, 1945. dyeing, hoping to convert from aque- (6) Bo"dm'n, G. L., Joumol of thl Soci"y (14) Roy", G. L, Zimmam'o, C. L., Waha, of Dym aud Colou,','" Vol. 66, 1959, p397. H. J. ,od Robineon, R. D., Tex/il, Rma"h ous systems to avoid pollution prob- (7) R,po" of Wa, Pmduution Bo"d Tnk Jaumal, Vol. 18, 1948, p598. lems as well as to take advantage of Commit"e on Dy,ing Nylon, Janu"y 19, 1945; (15) Sdmla, M. J. ,nd Remington, W. R, Di""n" L., The Ch,mical T"hnology of Dye. m,,,u,,'m,, of th, Falnday Sod,ty, Vol. 16, possible savings in overall cost. It will 'og ""d p,'nting, Vol. 11, 1948, p273 (R,inhold 1954, pp201, 246, 249 (Th, Abad"n Uni""ity take a long time to resolve problems of Publi,hing Co., N,w Y",k, N. Y.). p"" L,d.. Ab"d"o, Sco'bnd). (8) Bmok', J. A. end Reith, J. E., Am,,,,,,, (16) Anon, Du Pont T,dmk'l Bunetin, dye-solvent-fiber relationships, exhaus- Dy'''uff R'pDlt". Vol. 44, 1955, p698. No.5, 1949, p82. (9) B'ttk', J. A., Bmob, J. A., 1an",mn" (17) Gib,on, J. W., U.S. P,t. 2,663,612; U.S. tion properties of dyes and relative J. J. II. end bndal, H. P., Am"'''n Dy","!! P".2,663,613. costs of solvent versus aqueous dye- ing. It is difficult, however, to see how such a goal can be reached without considerably more fundamental re- search on these problems than is being done at present. In this country, two research programs have been initiated to develop the information vital to this issue. One is at Textile Research Institute and the other at North Caro- lina State University. Another challenge is that of satisfy- ing increasing demands for durable fire retardants on all types of wearing apparel, home and public transporta- tion fabrics, etc. Industrial research laboratories are active on this prob- lem but answers are needed urgently. Some progress has been made but performance levels and economics must be improved to satisfy projected needs. Here, again, fundameutal re- search on the basic issues - e.g., the effect of combustion products on the human system - by iudependeut research organizations, such as uni- versity doctoral programs, would be most welcome. Our industry, through the AATCC or independently, should be able to support more research programs. in colleges and universities as is done in many European countries. Whereas large textile firms in the U.S. have their own research organizations and modern facilities, many small busi- nesses do not and cannot afford them. Even so, I doubt that fundamental research is carried out even in those large organizations. Our need is for more young people, doctoral candi- dates and engineers, to become inter- ested in research for the sake of "push- ing back the frontiers of science." The WICATEX@SOFTENERLS-228,liquid softener, gives tow- place for this is in our graduate degree programs in the colleges and uni- eling a luxurious, velvety, soft hand and excellent wick-up, versities. Imparts balanced lubricity for shearing. Non.yellowingin Obviously I am not the first to sug- processing or ageing. Stored fabrics smell clean! Easily gest this but the challenges of our handled in bulk, Write for Technical Bulletin 44Q-ttv or future are going to be tougher and ask your Wica representative. tougher, so, it seems to me, our best preparation for meeting them is through the research efforts of our new, younger generations. 0:0 ,,,,,. IJatCa@ D"wn 'nd Oelon'" "gi",,,, '"d,m"k, of WICA CHEMICALS, BOX 506, CHARLOTTE, N. C. 28201 Th, Du Pom Co. iCli3ll!ii ,.-~ A OIVISION OF THE OTT CHEMICAL COMPANY

November 18, 1970 0:0 390/25

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