productisn
factors
Fiber-Fabric Relationships RENE BOUVET ,4rne&an
Viscose Corp., Marcus Hook, Pa.
EF0R.E attempting to chart a coum through the m e of complexities which confound the relationship of fiber properties with fabric performance, it might be well to say that much is still to be learned about the propertias of old and new fihers, about the impositions rasulting from processing strain, yam and fabric geometry, influence of finishes, eto., and thst the more trustworthy way to establish fiber performance ia by actual wear teats. Interesting advances have been made to appraise, through laboratory tests, many of the fiber properties,and today technologists are in a better position to chance an educated, experiencesupported gum aa to how fihers sre likely to perform in fabrics. Yet, the time is distant when a performance forecast can be safely baaed on the study ofa detailed fiber and fabric blueprint. An immense amount of march work remains to be done before the relationship lines between fiber characteristics and functional performance are well drawn and reliable forecasting becomes a reality. That textile experts should be 80 handicapped is not surprising, for profound changes and increaaiog expansions have aEected the industry over the laet 50 years. At the beginning of the 20th century there waa perhaps a half dozen natural fibera available-ootton, wool, silk, 5,x, jute, and animal hairsall growiug over a long period of time and, hence, exweed to changing conditions Btrecting their properties. To counteract their lack of uniformity, the industry perfected its manufacturing procedures &ugh years of trial and error. Although the knowledge of the fiber’s inner make-up remained limited, ita proceasing became time tested and set to a defkite routine.
B
September 1952
Then, man began to transform solutions of cbemicals into fibera in a eplit second. The age had begun when mechanical and chemical winiaardry outran nature in the process of transformation. Within a short perid, dreamera of magic fabrics became bleaeed with a substantial group of new fibem baving properties all their own. Scientists, having initiated those new fibers, had a better opportunity to explore their molecular mskeup, and they hold fewer secrets from man than those grown under the complicated process of nature. During the lsst half century, the number of useful textile fibers 6aa increased from sLr to over twenty-tM. A simple way to present these ia probably in two groupetbe natural fibera, then the man-made fiber, subdivided into hydrophilic and bydrophobic.
Natural Silk Catton Wool Jute Flax Animal hair
Available Fibem Man-Made Hydrophilic Hydrophobic Viscose rayon Dacron Acetate Orlon cupra Acrilan Aralac Dyne1 Vicara Vinyon Ardil Nylon Alginate Fiber@s . Vinylidene chloride Polyethylene
X61
No attempt ie made here to review the characteristics of eacb
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
2125
fiber. The discussion following deals with a few fundamental cbaracteristica in order to show, as far as feeble, bow they fit in the pattern of fiber properties versus fabric porformanca. TEYSILE SlRENGTE
..
counts. I t also infiuences the b r e h g strength and affects the feel of the cloth and its durability. Aa an example of fabric handle, consider two fabrics identical as to ends, picks, yam count, and weave. One eample is made of 6.6 denier %inch viawse rayon spln on the cotton system, the other of 5.5 denier rayon averaging 4 inchea spun 011 the worsted syatem. The contrast between their handle is striking, The cloth made of short staple is more bulky and gives the impression that it weigh8 more. The cloth made with the longer staple, spun on the worsted syutem, has a smoother face, a more compact cordy tauah, and feels leamr.
Tensile strength is an good a prohrty an any other to start with. It is a meaaurement of ability to reelst streases, generally expressed in grsms per aeuier, wet and dry. A atudy of the strew strain curve is neceaasry to de$rqrise the .qlatio&p existins between lo& and fiber deformetionS enaou$qd in yam and fabric manulscturing; P e d & man&I d , of. couree, are a great deallower than those &rupture point. W T H m PROP-ES The tensile strength of a I i b ia unqWMonably'mlated to Fiber Diameter. No less. important a role is played by fiber ita durability; however, o@er pmpertiiw and variables .. . i . diameter. Since a miuimum number of fibbers ia needed to meet &e& the life of a fiber. the requirementa of yam spinning, the count of a yarn,'apinnable When planning a &htwaightfab,nc,'sucb a+'% on Ourtain on a practical basis, is dehitely linked with the fiber diametar. material which is ellpected te &ad up well under properaswe, Small diameter fibers, in principle, permit the spinning of light=election of a high tenacity fiber nugeSste ita& beoeuee ekpsrience weight yam, of greater strength, greater flexibility, and better has pmved that a fabric osnnot'be serviceable unless it meets a capacity to reaiat the adverae in0uence of twist than mame fibers minimum strength requirement. In the industrial field where do. Coarse fibere generally impart grater rigidity and a more the ability to absorb a large amount of work often is the mdn resilientlike handle. Within oertgin limits, they resist Rst abraobjective,asinconveyorbeltsortiref~ric,hiehetrengthbeoomes sion better in the early atape but at the eame time are less capable one of the controlling elements. of absorbins Bex abmion. On the other hand, in SUitiOg, where there is enough rm*88 to Moisture Absorption. The relationship d m g between the provide a generous fabric strength, the importance of the fiber properties so far meutioned and functional performanas haa been tensile strength becomes less important and often yields to other relatively simple to describ in compmiaon to that of charactmadesirable characteriatcs such as handle, appearance, dyeability, ties like moisture absorpkn. Obvioudy, low moisture ahsorp cost,etc. tion, as &ent in mart of the new fibers, ofierssome advmtapcs It is. therefore. evident that tbs uwtief4 r a l 6 t i o W of ten& such as quick drying and high wet strength; but what about the a w n & with fudotionsl gropertiesis to be eva1aated;n thelight buman comfort an&? of the end WE. Thus, no general rtatement can be vgntured an The problem of comfort qualities in clothing are not too well to the preeiae role played by tensile ntrength, for the objective understood at the moment. It is generally accepted that moiaof the end uee dictates what the important pmprties are ta be. ture absorption is a necee On the other hand, wheu sity in a garment to be worn the objective involves comclam to the body. It is not plex functions, not always Heretofore, fdrics h v e b ~ e n constructed with the most likely that any test will ever d e h b l e and often not sep desirable 6bm,in amordaua with the 6ast practical texprove the need to be otherarable from each other, as tile logic, and with a bi& of -nomic& Funwise. What science can do in agarmsnt worn byanintional parformanos is appraisal b u s h actual wear mtn, possibly is to modify m@dustrial worker, it becomes and from such performpnas a backway relationship L eaciently the action of ibn extremely difiidt, if not tablished with the o & i d properties of the fiber. I n moisture absorption f i b hopeless, to identify what positions of fabric texture, of mechanicel handlinp, and so that they comply better part of the functional peri d u e n a of chemical m, tnnd to ohsoure the direct with the requisites of huformanceis the contribution linking of the orirJlul6her pmpertieu with the ultimate men comfort. Laboratories of a single or gmup of fiber performancs. In m n t yeam, notahle pmhm been are wor!dng on these requiproperties. made in measuring 6bm properties, and such values have Bites, but much time may helped to p d c t psaformanos, especially for industrial elapse before Sndingn of a end uses where the requirements a m more readily d&FlBBR LWGTa praoticalvduecometoliiht. able than they are in conn-tion with wearing apparel. Spec& Gravity. Specific Fiber length is an i n k At the same time, the advent of many new fiben and the gravity is another much die eating characteristic. It is endlessCOn&n&OMOf properdeu obuinnble by blending cuaaed6barproperty. The often more of a factor than has enLwg4 consideably the smpa of the study. Modem principal textile fibers range raalised. It controls the thinkiogpro-torgradually theprawntesquenca fmm 0.94 for polyethylene spinning system on which of "fabric to 6bm" supported by actual wear tests and to 2.54 for Fiberglas. Can the fiber can be processed, hop" eventually to inmrporate in a blueprint mawnahle thi. property be related to and each aystem of s p i n u i i modiiieationa to the original fiber pm@m to predict functional performance? imparts yarn characteristica The auswer is pees, espeoislly not related to the chemiin wearing apparel. Beeidea cal nature of the fiber. catering to neathetic appeal, The worsted syatem of spinning, for instance, &ing a m m e n t must be urotecfor long stsple, turns out tive, and its degree of pmteotion is largely related to ite power of insulation. Thus, the fia compact cordlike yam. The woolen system, with its low drafta, p e n d i m the yarn strength but favors the bulk, with ber which pmvidea the -test fabric t h i c k with the least weight sflords greatest potentisl protection. the result that though fabrics are made of the same'bec Cwf$dar two samples, identical in weigbt per square yard fiber they often are capable of unlike functions1 performance. and uor&uction; one is made of a fiber having a speciEc gravity Moreover, fiber length governs the range of thgspinpsble yarn of 1.14, the.other 1.38. The differenre to the touch Bpeaka for
+
-
2126
I N D U S T R I A L A N D .ENQ I N E E R IN G C H E M I S T R Y
Vd. 44, No. 9
S V W T Y E I I C FIBER
extreme brittleness Snd seriaua pmc4nsiug problems. The' &at widely used texWe fibers have at least 8% extensibility and are not truly stable. Most can be stahihed in the fabric folk by orocewes such as SanforiSinn for &ton. s t a b i l i s i resins for ;ideose rayon, and beat set& for the newer hydrophobic fibers. The relative dimensional stability of fibers is linked with the
-
then he linked ~peoi60ally to functional performance. It is hoped that fiber abrasion resistance values can eventually be related to the life of a garment exposed to lmown conditions. How&yft#ie 4 work required to realize such+ymbi+p,pyip. yF.hve pursued for many years befdre it bulhnates m practical 6ndmg~. The trade is intensely interested in abraaion resistance values, whether realized from h t , flex,or folded tests, but it is difficult to simulate tbe,variedconditioneunder,which.mg$pf tbp pr-ts are worn. Should abraaion resistance testsibe.w+eP,W f8bric rqpture or.to;+&%pint where weq:hae.;so F e d the.fabfic atsength that it ceases to be servic9r,ble?. Add to tbig the. intlueuce of fabric @i&es: Lubriwting poperties i n p y a ~ ethe a b h n resistaqoel whereas thhse oE a ,&ous:nature~&we it becaw they aot 88 .abradants. , These,we a ,few.of the variables which greatly.coorpliaate the (ask shead. ,, , . , Present l 8 b @ ~ , & r a s i oreaiataqq n tm&s;pield onlp indicationrr. :. '&'hey ody w k q ,it poseible:tq Bemgakq @e very tgcod~ fromthe very poor. ., , .,.: Stren!+?ain C w e r . The f i b w ~ s ~ a . @ r ec& a means for venturing Bome predictions.. the, e m . teristics of thk OWE is its ultimate value or break point, Howeve?, the more subtle CBB between fibera that determine their p4ormanc.e q. more to the shape of the cuwe rather than +the ul-9 values. Considerable ,difficulty has heen experienced, in attempk to numerically deecribe the shap +. curye, and the most valuable approaches contours in term of,
$9
'
.
wiof,
in ksrying am&nta,. as found h fiber blends. %th fuhctional performance. Blends. Blends of fibers are U t e io their combinstions if left to the imagination. Bowever, they must comply with principles predicated on reasonable cooperation of fiber lengtb, harmony of extensibility. similarity in drafting properties, and
dustry still must we the method of trisl and e m r to find practical answers. From the moment that the expected functioual performance h&'t&i conditions under wbicb fabria are to operate are well da bimqelf in a fair position to reach f meeting the requirements, at least, are promising rovided coat does not take precedence, ' P. but the rugged competition existing in the textile induatry s e e m b,hold the cpst,factorin,thp front line at all times. .'.A. Great progrggp has.alredy been. d e in the indwtaid fi&d to,determine the type. of,fiber that should be ,directed to& : , specifio endmea The.astapishinggr0wt.b of visoose rayon in tiw t k e induetry ie sgood;illustration of how clasely fiber char&?.ieri~ticeend performance can be correlated. The euccess of V i s o o ~ erwon in the tire field bas been and still is predicated on ..thoexploi@tiQn06 properties,evaluated in.thefiber f m . They are,* rotio of weight vemue stre48th,.,eJonpation, +esion @.FUpber, ,wdder resiatape. Tbex can be detsrmined with .Isbor~,mtvw,,.an~ the present determieatiaaa we reliable B s&ndard perfomnce can
to strain constitutes the main requirement, properties evaluated from the fiber used as a guide. There is no question that induntry more on this approach 88 instrumentation and testing metbod: reflect truer values. FORECASTING FUNCTIONAL PBOPEUTTES OF F*BBIC%
The ambitioua task of forece.~tingthe fqmtiond p r o p r p e ~ of fabrics conceived for appp+, ffiwrding to used therein, will de+ ye" to mate: s e m h is needed toembo*.in a,comrnimded..e r a w for drape, hdle,,crease re&tanq*w ! The amount of work required to reach & he It may well be that the practical value of such
become more clearly indicated before it receives the support of a c o n d industry-wide effort. At present, fabric wear tests must be used to judge the fiber. Conclusione are drawn from the performance, and on reducing such conclosions to spedcations a modest form of cornlation between fiber c h a r d c a and fabric performance in achieved. For many years pant, the U.8.armed forces have been uning the Speci6mtion appmsch to secure their fabrics. 8pedIim tions set limits to minimumbmad fuuctionn and general conetructim, leaving nome freedom 88 to fabric details. The experience being accumulated from “the cloth to the fiber” agpaoech is psving the way to an eventual reversat of that sequence. Today the fabric eugineer is faced with evalimting m y fibem with ever-cbanging properties. Perhapa only a few will meet the long-term requirements of sucoeas. Discotrery of a “revolutionsry” fiber does not u e c e d y make it a pal textfle fiber. It taken fully 10 yearn to develop a promising fiber and another decade to apply it properly. A p d understsnding of the poeaibllitiea and poteutialities oflered by new fibem depends on familiarity with their chemical and physical properties and a knowledge of the mechanics of textile mauufsctudng and the limitatious impoeed by mass
production methods, which are more widely used in the teroe industry tbun in commonly suspected. There are also the problems involved in meeting a prevailing high efficiency in the induatry, rugged competition, and unendiug cb8nges in the labor pattern. This information should supplement an intimate knowledge of exktkq fabrics and their performance before it can be used intelligently toward ihproving present fbbrica and deaigning new ones. Engineers of moderp fabrica should be fowway blends of science, mechanics, business, and inspiratiOn. It is natursl that they should be able to design more functional fabrics than have been made in the pant because they have more raw materials at their din&. They are ale0expected to build from the gnwnd u p t h a t in, from the fiber to the cloth. This method will gradually supernede the present practice of manufacturing the cloth and then appraising it. Textile engineem will eventually succeed in drawing fabric blueprints and applying adjustment factors to convert the fiber values into fabric performance. The task ahead in replete with hurdles which time and science will eventuslly conquer. R = O W ~ Dfor rosier
Aaemrrm M W
~ u o 81.186%. h
ax. 1852
Cost and Availability of Raw Materials HOWARD BUNN Carbide and Carbon Chernicah 6.SO .Fmst Mnd St., New York 17, N. Y.
HE chemical industry has
, 1
been a major force in the
that will d e d i n e the
T
reeant evolution of the
textile industry. When textiles came predominantly
an many oomplicated and intermhted factom SU-B or failure of the newer synthetie h m . Critical are the u m t and aveihbility of the raw materials. If the newer 6bem an to attain d maturity and fulfill their early promise, they must eombins d i d pmfomancs with d y a d a b i l i t y at lol* m t . The intxoduction of new 6bem and expansions in nylon and rayon pmduetion are exeating new marketa for mnnp brsic &ani&. The eventual nsulta of larger production of r-tile m materids should be a bnveriq of casta and a more general availability of intereatbq & e m i d for pl~tica,surfsea matinis, and other products far afield from tcxtllesp ben&t to all industry.
from n p l d nstural nourcea, the volume of chemicals required for processjng, dyeing, and 6ni8hing the fibers wan negligible. The comnm&l inhduction of rayon in 1891, and improvemeuts in the techniques for mex~ e r i s i ncotton ~ muresented the debut of ohemistry’s e5ork to duplicate, modify, snd improve on the p r o p erties of natural fibers. Today, the cbemical industry hae broadened its role to the extent tbat textiles now provide one of the largeat markets for &em&&, and textiles in turn derive their most promssive developments from these chemicals. The textile pmducing aad pmcewing industries now actually consume shout 25% of all the industrial chemicals sold. Although the uewex synthetic fihpmdnction presents many interesting poeaibilities far f u t m chemical developments in terms of intarmediatea, nolmts, Gniabes, and d i e d ne&, rayon and wetate production require far greater qusotities of chemic& 2128
from h e a d p o i n t of toasy’s consumption picture.
I n 1951,865,400,000pounas of rayon and 428,800,000 pounds of &te were p w d u d . Rayon production required on the order of l,aoO,000,000 pounds of cauatic, 300,000,000pounds of carbon biaulfide, and l,l00,OOO,000 pounds of sulfuric acid in addition to a billion pounds
of cotton h t e r s or wwd pulp. Acetate pmduction required approximately 700,000,oM) pounds of acetic anhydride, a billion pounds ~ care of by recycling of acetic acid (the bulk of whicb w a taken recovered acid), and 85,000,000pounds of acetone in addition to 300,000,000pounds of pulp. The raw materials for the new synthetic fibers reprenent a potential market for chemic& in the textile fieeld that may even exceed the present need8 of rayon and &te. When a new synthetic fiber in developed or an existing one expanded, the volume in of such magnitude that it hecornea neceaaary to expand production of basic intermedhtes or develop new p m e m 8 and intermediates. The d e e t of thia inmased volume is
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 44, No. 9
’
