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CALIFOR.i'ITA STA1'E UNIVERSITY, NORTHRIDGE
PRESifF..INK D.RYING OF FABRICS IN I'l!CROWAVE OVEN \\
A thesis subm:i.tted in pa:r-tial satisfaetion of the requirements for the degree of Master of Science in
Home Economies
by
Gertrud1;;1 Ml,)rrison ...... He:i.ma..."l
i '··· -··-··------·----~------.--· ------·-····· ····- ··--····· . .
~-. -'----.. ------·---
The thesis of Gertrude N:orrison Hsiman is approved:
Callfo:t I! l ! ' l I l______·------· ·····-· ---- -·--···------· ----·------·----·-·------·-·------ iii ,~,·~------·-· -~ I I ! ACKNOWLEDGNENTS I I wish to express my thanks and gratitude to all the people I whose collaboration with me hs.s made this study possible .. Special thanks go to l1iss Susan Richards for her contributions, suggestions and the loan of her books. I ,~ thanks also go to Mrs. Betty Bailey, :t i· i I ! i I iv ______, ______I ! TABLE OF CONTENTS Page TITLE PAGE ••~•••••e•••••••••••••••••••••••••••••••••••• i .APPROVAL PAGE ...... c; ...... Ql •• ,...... , •• ~ ••••• e • o ...... ii DEDICATIOt1 o ...... e •••••••••••••• ~. iii ACKNOWLEDGMENTS ••••••••••••••~•••••••~•••e••••o•••••••• iv UST OF TABlES ...... CJ -ft •• •-• ••-• •• (t ...... vii LIST OF li'IGUR.ES viii ABSTR.t\cr •••••••••••••••••••••• ~ ••••••••••••• s- •-• •• .,. •. "'• ix CHAPTER I. INTROJ.lJ CIT ON 1 Objective •••••s•~•·•••••••e•••••~••••••~•••• 1 Justific~tion e~···········-~···8·~·········· 1 Hypotheses 2 Assu."Ylptions 3 Limitations •••e••~•••••~~'••••••••~~•••••••• 3 Definition of Terms •••••••••o••••••••••••••• 4 II. REVIE"~!l OF LITERATURE ...... 5 Shrj.nksge 5 Nicrowave 17 IIL PROCEDTjP~k,; •• ~ ..... " , •• .- ••••• • •••., • "' •• 4t ..... ~ •• .., ••• 24 Pilot Study by Author ...... , ...... , ... . 24 Test Procodure 26 Oollf)ction eJJ.d Evaluation of Data • , ... ,...... , 32 ! ----·------·------··--·------· ---·-----·---··-···--·-··-·---·------' v r-·------·------··------·- l 1 I IV. TEST RESULTS AND-OBSERVATIONS •••••••••••••••••• J5 Test Results ~oeeee••~••••••••••••••••••••••• J5 Observations •••••••••••••••••••••••••••••••• J8 v. CONCLUSIONS .AJ.~D RECOMMENDATIONS •••••••••• •• •••• 4J SELECTED BIBLIOGRAPHY ...... 45 I 1 I APPEND[XES ••••••••••••••••••••••••••••••••••••••••••••• 48 I- Appendix A. Details -of Specimen Holder • ••••••• 49 Appendix B. Automatic Washl:ng Machine •• p ' Op eraw~ng arame~ers ~••••••••••••• .50 Appendix C. Dr,ying Apparatus Parameters ••••••• 51 ~mensional Changes of Selected Fabrl cs after Laundering Di"ied I under Three Conditions ...... 52 I Appendix E. ·- Area Shrinkage after One and Five i Lau.ndering a..~d Drying Cycles of !· I Selected Fabrics •••••••••••••••••• 53 ! ·i l ! ,------··------.l 1 I I LIST OF TABLES I Table Page 1. Elastic Properties of Various Fibers at Selected Extensions •e••••••e••~•e••••••••••••••••••••••••• 7 2. Percent Swelling in Fiber D'lamete:r and Length of Selected r~bers ~····•••••••-••••••~•·•••••••••••• 9 3. Fabric Description of Selected Interfacing and Underlining Woven Fabrics ••••~••••••••••••••••••• 28 4. Laundering Conditions for Selected Intarfa~lng and Underlining Fabric ·-··••••••••••••••••••••••• 30 .5. "F" Table after First Test cycle •••eeGe•••••••••• 39 6. "F" Table after Fifth Test CYcle ···············~· 39 !. i ! I I i t -·--·---~--- ~------~·-· ------.... ~------"·------·----- . -- ·------. ------"·--- ·-- ______.i vii ------·------ IJ:ST OF FIGURES I j :Figure Page 1. Typical Stress-strain CUrve of Textile Fibers ••••••••• 6 2. Approrlm!ition of Yarn Cross-section Showing Fibers l and Interfiber Space •••••••••••••••••••••••••••••••••• 10 I J. Forces Acting on Yarn AB Assembled into a Plain I Weave FabriC ••••••••••••••••••••••••••••••••ft• 6. The Effect of Fabric Cover Factor on Fabric I LalL~dering Shrinkage •••••••e~•·••••••••••e•••••~•••••• 1.3 of 7. The Effect Weave T;y-pe(Constant Cover Factor) I upon Fabric laundering Shrinkage o•••••••••••~••••••••• 14 ! 8. The UHF Spectrum Indicating Relative Position of the F~equency at wr~ch }ftcrowave Ovens Operate •••o•••• 18 9. Interaction Between Microwaves and Surrounding · Medi.a ••• ~ •••• : * ••• o •••••••••• o ••• ~ • ~ ...... "' ...... 18 lO. Components of a M:tc.ro\#rave Oven ...... 21 11. Average Lengthwise Shrinkage a11d Average Percent Shrinkage of 10 x 10-inch Specimens after First and Fifth Laundering and Drying ~Jcles •••••••••••••••~ 12. Average \?ldthw-lse Shrinkage and Average Percent Shrink2.ge of 10 x 10-:l.nch Sp.ecimens after }l~rst and Fifth Laundering and Dr7lng Cycles ••••~••••••••••• Average Area Shrinkage of 10 x lOw.inch Specimens I after First and Fifth Laundering and Drying G.vcles •••• 40 I I i I I I L ______------ viii I I ABSTRAC! PRESHRINK DRYING OF FABRICS IN MICROWAVE OVEN by Gertrude M. Heiman Master of Science in Home Economics June , 1974 The object of this research was to determine the effectiveness JofI a domestic microwave oven in the preshrink drying of selected I !interfacing and underlining fabrics. A comparative study was I . . I jconducted to determine whether the method of drying (i.e., tumble I idry, mi.crowave oven dry, or room-line dry) does significantly affect !the dimensional changes occur in the preshrinking of selected I ~hich I I iinterfaclng and underlin.i.ng woven fa.brics. I i The fabrics for this study were selected as representative of I I ;those available to consumers in Southern California4 These fabrics I iincluded one cotton, one rayon1 one polyester, two polyester-cotton I I ;blends, one rayon-polyester bland, and one rayon•polyester-goat ha:lr i !blend.. All fabrics tv8re of plain weave construction that did not 11•equirt) ironing when subjected t.o hom.e laundry processes. Specimens were laundered in four-pou.nd loads ac(!O:rding to I ·:procedures typic.:il of those us9d in the home for preshrinking iptn•poses and ace·ording to !HJC:;:>pted test. procedures.. Specilnens werl:'t ! i 1...... ---~~---·--·- ·--·-·------··------.. ix r:::::.::~::::g~.t::i:,:::::::d~ng p~~dur~--t~ble dry, ------~ . I I Five laundering and drying cycles were carried out. Specimens 1 I I 1were measured before laundering and.after the first and fifth 1 laundering and dry:!.ng cycles. 1,, I The changes in dimensions indicated that in the preshrink I i 1dryi:ng of. selected interfacing and U.""lderlining fabrics, the method I iof d..."7ing, whether by tumble dryer, microwave oven, or room-line I !dry, does significantly affect tha dimensional changes which occur. !The microwave oven is not recommended for the preshrink drying of I i !fabrics. ·I I I,. I I I I l ·j i ! i ! L--·------~------·------~-----~---· ------~ -- X r ·------· ·------. I ·j ' I I aiAPTER I INTROOOCTION In a reeent publication from Litton Microwave Cooking Center, I !Ludvigson suggested that approximately a yard of fabric could be I ; preshrunk in a. domestic microwave oven (9:63). A review of the I I textile literature disclosed that microwaves were being used in lthe'processing o£ textiles to dr,y dyes a.nd finishing agents (27:6). I l However, no information was found rel.ating to the preshrinking of I i :f'abries With a domestic microwave oven. I \ j£P~cti~ I 1 The objective of this study was to determine the effectiveness i i of a microvrave oven in the preshrink drying of s-elected interfacing 'j and underlining fabrics. l I !,_...... ,___ Justification I . I A problem for the home sewer is the tgndenc,y of textile I ! materials to shrlnk or stretch dUJ.-ing the first few launderings and subsequent dr·yings.. Such dimensional changes t and ospecia~ly shrinkage, in apparel fabric .may render a fitted garment uncomfortable and sonH.:rtimes even useless. ··A lengthwise shrinkage of only 1.5 percent ca..n cause a change in dress size .. Textile m~~ufacturers do treat fabrics with various mechanical .a:nd e.i1e.r.'..ica.1 finishes to p:ceve:nt e.ha.nges in fabric di.IUensions ...... ------·- ...... - ...... --...... - ... ·- 1 F"'deral Trade O.;mmiss:i.on (20: 31'1) .. T·o a v·o:td the i:m::-onvenien:ca of f 1~otions before they ar~1 cut (10:98). It is cu:ricms that many necessary r,;l ti.1. prf2•r.>b.runk goud.s.. Clothing const.ructicn experts cutting. These experts suggested that the preshl"inking.. of texti.1~S• r!la.terials be :performed by the method that will be u.s~d to ol€!au by drying J.n a mic:t"OTf<>.Ve oven could make home preshrinking .faster .. Preshrink drying of .fabric in microwave Oifen should ne verified.; N111.1 hypothesis: There is no significant different.-e bet:waen t.l:l~ di.mansion~J. changes ·w.o.ich occur during tht~ preshrinking of selected interfacing and underlining fabrios when dried by tumble dryer, microwave oven ~rking hypothesi~: There i.s n significant difference between the di..'llansional ehMgas which occur during tiu~ preshri.nking of selected interfacing 3 -1------·------~------·-··------~------~-''-1. 1and underlining fabrics when driad by tumble dryer, microwave oven . ,, I . !drying, or room-line dr,r. 1 'jAssumptions I: I l For the purpose of this study, the following assumptions are I1 !accepted: I I Consumers construct. maily of their own garments. I I Fashion fabrics, underlining and interfacing materials, and sewing notions are preshrunk in the home I I · by_ consumers to assure dimensional sta.bill ty. · ! constructed washable garments are cleaned i Home I I I by laundering and s1.1bsequent drying, which might cause I shrinkage if fabrics were not preshrunk by the consumer. I l Preshrinking may be accomplished by several methods; i the pri_mary one is la-undering and d.rying of the fabric in the home washer· and d..-yer .. I I The microwave oven is becoming a c~w~on kitchen appliance in the home. I I I ILiru.i tations l~---- l i The scope of this study w-as l:hni ted by time, money, and equipment i i !avai.lable to this resear~~er. 1be research was m1dertaken only to I ' :co:n:para the dimensional changes of salected fabrics when sub.Jected to jY8Xious drying proc<:dures durlr;g the presh..-..i_nldng pr<.wess; the study Since the vent:.i1atj_on cap!lbili tles of the dom.estic mi.crmn~.ve [ ov-sn l..i.rrl t the size of drying load to approx:lmately one yard of' fabr.•ie, interfe.~ing and underl:brl.ng fabrics were selected for testing pl.U"poses~ These fabrics represent fabr1.cs that th·rs consumer might use in one-yard amOlli'lts. Fabrics usad in this study were representa tive of 'those a:'lailable f<.rr . plrln weave const:.·uction which have the most potential for sb.ri.r-..kage. This will be dlscussed in the revi~:1w of literature., ::Lab\1rato:ry evaluations were conducted :i.n an e.ir cond:i.timH:d labo:~atory .. Defini t4o..n. .?:f. '!:!,;-rTlS_: Domestic microwave oven; Counter type microwave oven operating with 120 volts and a., c. poittar su.pply. Fabric st.abili ty: Rssistance to dimensional change . (24:84). Preshri:nking: rlashing and drying of fabric prior to cutting for the construction of a garment to prevent a subsequent det~rease in dimensions of the fabric. F.I~VIEW OF IJ:TERATtT'ftE Intrcduction «:""''><"C A search of the li te:ra.t.ure did not re-veal ar~r previous stu~ties Sh:r:i.nkage is defined as a decre.sse in d:i.!lHmdc·r.ls o:f s. f~:tfJ:i.c ~A3 a result of W!$tting :md rn.1bsequent dryin& ( 24: Tl.ll). TI:w Ral.axs.tio:1 sh:rinkag!J.'I: Rela:xaticm shrinkage :i.s the shrinkage acor.m;par,ying the release of fiber strains impa:rtad during manufacture of tho fab:r.:ic.. 1'he magnitude of this effect is dependent on the stress-stra:i.11 chru:-a\:'ite:r- istic of the fiber composing t.ha f~.b!... lc., Stress is the load per unit area whieh causes st.rain {9::350). The strain :J.s the elongatj.on U."ldar- gone by the fiber caused by exte~1al forces (13:1.5) (7:626-627).• A typical stress-strain behavior of fibers is shown in Figure 1. 5 6 Strain F'igu.:t-e 1. 'trpical stress-st.:r~tn CUl'Va of textile fibers (7:627) .. The i11i tial stt=~ep Jj.ne.:J.r portion (A) corresponds to a sl:i.ght st:t... etc.1:1ing of the molecule chains themselves, s.nd to a straighte:.1ing of the molec·ular network in the non-crystalline t·egions, with a. consequent st:raining of the cro0s~links between the molecules. If the fiber is stretched with.i.n the R~"Jg.'i.cm A~ the fiber recov-ers J.t~; or5.ginal 1· T.nbl<:J 1 represents the stress-strnin character'istics of fotU' T.ABl.E l ELtB'l'IC PROPER'liES OF Y/;RIO!.JS l'"'IBERS A'I' SELECTED EXTENSIONS (1J:92f 100, 273, 406) Cotton 9 Wool 100 (wet) Rayon External conditions and fj.ber macrostructure also affect the fib(n• rela..1eation shrinkage pr.>tantial.. Water and heat reduce t.he ntltrtbE (14:409) .. \ :tibars.. Speclficallyt the cross~links of cellulosic fibers tend to be broken and rapl~cad by water absorption on the hydroxyl groups. Hearle of the Textile Institute states that if a fiber wh.i.ch has been stret~c,"'l.ed beyond the elastic re<.."'very area and left extended (area OR of Figu.re 1) is i<"'.nnersed in water or treated with steam, a..1most to its original form. on subsequent cliJ-ring · (ll-t-:J32L In natural fibers 9 the complex cellu.lar structure gl•er;~.tly affE:;cts fiber extension., The angle of tha crystalllno spir'al of tho cell wall is correlated with ela-sticity. Extension takes p1lH!e by stretehing out tha spirals like a spring with flatter sp:l.rals have higher extensihtli ty than have: pls.nt fibers with steeper spirals (7:26.5). 'l~"le possibility of straining the fibe!'S during fabric manufacture is higr-Lly· probable. D!"'Y stresses stra imposed, particularly in weaving. Stresses are also inevitably im.posed on textile mater1.als in the wet state~ suc:h as during c.yG:ing a.:nd tentering processes (26:7}),. Fibers strained in manufacture w:tll revert to their normal ~mstr~tched dL~ensions under tha warm, ~ret} tension-free ccmdi tions of the first few home launderings and subsequent dryings Swelling shrinkage: Swelling shrink1-1ge results from the swelling and deswelling of the fibers due to the a.bsoz-:ption and d~s:orption of water. The magr.i tude of this effect depends not only upon the fiber, but also upon the fiber interaction of the yarn and fabric structure · (24:Tlll). . . . . 9 0 CCUl" S ,ju:r.·i.ng the ini t:ia.l h.Olil(l laxtnde:d.ng after manu£ acture When textile fibers wlthin a fabr:tc sc-rell i.n w~?.ter, the water molecules penetrate the f:l.be.l"· ar1d force the libel' molecules apart .. Since the fiber's lor1g-chain il101ecu1es are orie·:r.d:.ed pal'&11al to the a:x:ls, the diameter of the f'ib(~r will be co:n~SiderabJ..y increased; howe'ver, very little inc:ee.ase :i.n length will takt:'> p1a.ca (13t72) • Table 2 J.i.sts tho percr:mt increa~;e o.f tlH:! d.i.rJm.el:.e:l:' and length of four f:i.ber·s. Although the :rese;;.r~her fo0.:nd no r-eference to diF..mettJ:r:· increa.se for polyester would be less than nylon sines the muistu.ra regain of polyestt3!' ·was O,.J} or 0.8 percent depending on type, compared to 4.0 to 4 .. 5 percent moistlU'e regain o.f nylon (31~10). TABLE 2 PERCENT 3\-.lELLING IN FIBER DIAliE'I'ER AND LENGTH OF SELEGrED FIBERS (1J:71) Fiber The e.ff*)cts of th-s fiber swel:!.ing can be observed in yarns as a d:l.a.tneter iner>t~a.se of the ya:l"11,, 'tb.li:) incre.::;>e depends on the araount of fiber s;mlling and th~ ..?.\.1lount of ~uJ.terfi.ber space in the yarn. If there is n·~7 free :interfiber space in the yarn, the yarns must increa.se in dia.'11.eter by the same ruuount as the fibers swell. (26: 74) e . . twist and woven interladnE;s (6:8.5-87). li'igure 2. Approximation of yarn crcss~.sectlon shovJ.r.g fibers and interfiber space (6:90) .. Since fibers spiral a:Nn.trd in the yarn, the yarn l'!liJ.st e::i. thar un- twist or contrfwt itl length if the swollen iibe:rs are to ma:intrin their Ol'iginal length. Yarns in fabrtcs cannot untwist beca'J.se of the interlacingsacting on the cross yarns. Therefore, yarns rmst contract in length when their fibers swell. Collins has indicated that when a cctton yarn of ')~ 7 twist multiplier increases in diameter by 14 percent, it is not likely to shrink ml")re thari two percent .. Yarn shrinkage d11e to swelling- therefore, is not the prime source of cotton, plai1'1 weave fabric shl~inkage (26~?4). Fabrics of fibers with greater swelling properties than cotton would be expected to have greater yarn shrinkage; conversely, fabrics of fibers with less swelling property than cotton would be expected to have less yarn shrinkage. • + . . . . ll 1fove:'t fabrics are produced by int€lrlacing two sets of yarns at right angl-&s.. 'fhe 1)la:i.n wes.ve ha.s the simplest possible pattern of ::.•esulti:o.g in a. fabr:l.(~ which tends to ba fin:'l, res:i8ts yarn slippage~ and may exhibit a great deal of shr1nka.ge (16:24). th<3 area of the cloth covered by the warp CH' ·w<:lft yarns, Us:3.ng thtJ it :ls possible to calcttlate th•" perce.ntage area of the cloth coversd by one or more thre.r.ds. Thi.s is defined as the "cover facttJr u (16:30) .. y·.arns, when assembled. :i.nto woven fabric, exert forces UFlOl'l. one another at the crossover points.. (See Figt\re J.) 'fhe forces cause the warp and weft yarns to crimp (16:2.5) (9:1)1, 136) .. :s Figure J. Forces scting on yarn AB assembled into a plain wea·ve fabi-ic (9:1JO). the plane of the f'abr:i.c, p.r:.rallcl to cmt) set of yarm>r as in Fi.gure 4(B) !> the eff crtmp will redu.ee fabric length.. 'I'tt::Ls c:r:tmp exchange rrw,y occu,:r in woven fabrics (A) Weft yarn \IJarp yarn F'igtwe 4. Cri.rnp exchange du.e to applied tension (t) (16:.:34) .. The primary cause of' cotton and other cellulosic woven fabric shrinkage is the mechanism of c:::'imp adjustment. When yarns in a fabric are wet and swollen, one yarn has a longer bending path to curve aroa~d a swollen cross yarn. The first yarn must either increase in length or, alternatively, the cross yarns must move closer together. .A:n increase in warp length reqw.res the applicat.i.on of tension, and therefore, nhen tension is absent, the path of least resistance is taken and tha waft yan1 spacing decreases. Hence, the fabric shrinks in the direction of the first yarn (3:240-241) • (See Figure 5.) The mechanism of crimp adjustment would be negligible for thermoplastic fibers as they have so little swelling. lJ r I i I lI I . Figure 5. A geometric explanation of cloth shrinkage (26:74). (Note the increase in warp crimp.) Figure· 6 illustrates the effect of the cover factor of plain weave rayon fabric on laundering shrinkage.. The tighter fabrics I1 - 1shrink more than the slacker f.abrlcs (26:74). J8 ...... ~...... 34 II) -~ bJ) 30 Jj ·s:: • ~ ,J:l en 22 G) ~."' < 18 20 22 24 26 2.8 Total Cover' Factor Fig~re 6. The affect of fabric cover factor on fabric laundering shrinkage (26:74) • .Another fabric .construction shrink.;;q;e effect is seen in I !Figure ?.. \'lith ths same cover factor, weaves With more interlatU.ngs ! !shrink more than weaYes ld th fewer :tnter1acings .. I : i i L __ ---.. ------___ .. __ ------· __ .. __ ------...... ______-----·------... ------______, ______J . + 14 ~- - ("'- r-- Basket Twill Plain 2/2 2/IRH Weave Type Figure 7. The effect of weave type (constant cover factor) I upon fabric laundering shrinkage (26:74). I I To minimize shrinkage, manufacturers may give fabric a finishing !treatment designed to establish dimensional stability. Compressive I ~shrinkage is a patented finish that raduces shrinkage in cotton and jlinens. Fabrics shrunk by this method are identified as "SanforizedR.nj I I ! \The process mechanically "sets" the fabric at a reduced size. When I ! Jthe cons'Ui.ner .first launders the fabric, relaxation and swelling I ishrinkaga occur but Y..'i.th the resultant dimensions the S3llle as that ·at ! I ~hieh the manufacttwer "se~'the fabric (15:90-91). l I I SanforsettingR is a shrinking process used to finish rayon ifabrics .. The fabric is impregnated with a slightly .9.cid solution ot• ; I :glyoxal, then dried a.nd finally heat tre.ated., The hydroxyl groups of I I 'the cellulose molecule become esterified and therefore reduce the i l iamo1mt of water absorbed by the fibers so that less swelling is i /produced (4:268-270)., I I L___ -·----··-··--··· -·-- ····---·------·-· ·------·- ---·· ·-·--·--···------·- .. --·-·-··-·------·----··------··---·-··---···--·-----·- ··-·- ---' ...... 15 ------, I Po~ester and other synthetic fabrics are given a heat setting . 1 treatment to establish fabric dimensions. This stability will be 1 1I • 1 !retained provided the material is not heated above the temperature I I I lat which it was set. I Increased dimensional stability is a beneficial side effect of I jresin finishes which are applied to cotton, rayon and other cellulose I !fiber fabrics. The resin left within the fibers occupies the spaces !between the molecules and reduces swelling. Some resins combine I,chemically with adjacent molecules and cross-link the fiber molecules I, ! i lin a more rigid structure (4:1).5, 1)6, 140). I I . I I Felting and progressive shrinkage: ~~~- I Felting shrinkage resu.lts from the movement of individU!ll !fibers. wit..lrl.n yarns and fabrics. The fibers migrate and entangle I IWi th each other caus:i.ng an inc::.•ease in density and an accompanying I !decreasei in area (17:260). !_I· I l Iu order for fabrics to felt, the fibers must be easily !extensible when wet, and they must have some power of recovery I /from eA~ension when wet (26:74). The rate of felting is increased 1 I ! ~the presence of a directional frictional ~ffect {D.FoE.) i ! I twhich makes ::l.t possible for tha fiber to move or be IllOVed more I . leasiJy in one direction than in the other. It is accepted that ; 1the D.F.E., of wool is caused by the scale structure (17:261-262). Mechanical actinn is ~lso nec~~s~ry for felting to take 'place., vlhen alternating compression and relaxation forces are I .: ;applied, the corn.pressi ve :forc8s pack fibers more tightly together, i :and upon relax2.tion, the D.F'GE~ prevent-s many of them from reverting L·-~------·- ·-·------...,----·------~- .. --~----~-----~------~--~------~- ______j • + . + • + . ' +•.. o t'ne i r orl.g~"i..mu.. . .. pos:lt-t . ....on ,fJ? ~ ~ .2/2'.o J ~ Wool surpasses sll other fibers in thil ph.,vslcal ::p;~al:tt.ies th.a.t make felting possible. Other axrl.ma.l ha.irs possess tho felting property, but they ha-v-e l:i!a."\.t.~d com.--nerc:lal Utle (17:98)., i>Jhen vrool is blended with other fibers 9 its .felting qltallty is reduc~d" Pardo 60~40 percent cotton-tr:ool blendt9d :fabric, it is difficult to find ev:td.ence of felting .. Chlorination is a chemical nH'lthod of treatii.1g wool s? that tho;, fabric wi1~ be shrink-resi.sta11t. The surfacfJ ~;c&tles of ·•·mol an• modified so that the D~F.E9 is decreasedf thu.s 9 the felting qual.ity is letssen•3d. (17:266-26'7). ''lc.ol fabrics which have received this treatment are labeled ~~washable,. 'l Other m.ethods us~d to contr<>l the shrinkage of wool include: (1) treatmal'ltS with enzymes tha.t attack the fiber scales; (2) the use of silicone :fj"nishes that add -w·ater repellency as well as stability; (J) the interfacial polyrrwrizat.ion methods (8:335). Shrinkage due to fiber Migration has~ however, also been observed in certain circuahstanoes in non-sce.Jy fibers. Under certain conditions, some types of rayon staple fabrics have exhibited fiber movement, and shrinkage occurred after the ini tj.al relaxation arAd swelling shrinkages h~d occurred; hence, the tem ~progressive shrinkage" (26:74). . . 17 Yarn and fabric geometry can deteniJ.5.ne the @.mount of progressi:ve shrinkage., Rel~.t:'1. ya twist direct~.Lons of wtu'p and .J... 1··u J. ng yarns, cover factor, ya.rn :number a:nd staple length, all affect total progressive sh:rinkRge.. A high list modulus. :r!3ycn ·would be less liable to progresslve shrinkage than one 1-d th R J.o'!ii ¥-ret modulus (26:75, 76s 99)~ Microwaves Microwaves are electromagnetic radiations l )00,000 and )00 :megahcn:tz (1\fHz-) ( ~-~:':!? 10'';~ The relationship of wavelength •tnd frequency is shown by th£• fol.lo-;.'i.ng .i'o:rmula; Wavelangt.h x freq11ency = Speed of light. .. Within the ultra high f:?."equency ('GB.F) spectrum.J the Federal Communication O:muni~;sion ha.s allocated seve:Nll bands for inchJ.strial,. scientific and rne.::li.<~)'-1 purposes (sordet:Unes called ISH frequ~)i'h'!Y ba..nds) .. Ths nrl.c7t•owa.ve oven frequencies art' located within the ISM baJ:'lds .. Figure 8 illustrates the relative poosi ticns of the microwave oven (19:11) .. ~ficrowa.ves ara noni.onizing energy which cause a rise in temperature within the penet:cated substance. As microwaves penetrate substances containing polar molecules, these molecules move at a rate equal to the rate of the frequency of the microwaves. The molecules . . 18 I'!OYe to magnetically align themselves with the magnetic field produced by the microwaves. 'rhis ~novement results in friction between the molecules, thus producing frictional heat. Lossiness is a term used to exprerJs the degree to which substanceH wlll absorb n1icrowave energy (18:23) (29:4) (22:10). rl ~ 0 0 Q I ';! 0 II s::ro;g it ] ~ 0 f.« ... 0 ~ell r-f p• ~ M ¢I QS. e ~ ~ +'" bDG'l"' 0"0 4!.1 I ~'tfl!) $1d ~ ~ ell·~~ ~ ~ 'P l2; "" ~ .~ H 1l • I ' 300 ··~o 1500 2100 2 700 :3000 , I YJ.erowave Oven. ¥.d.crowave Oven Figure 8. The u.tfF spectrum indicating relB.tivs position of the frequer..ey at which microwave ovens operate .. H6ating afficieney of nrl.croua·ves is high because the heat is ·• created by polar action uithin th6 medium.. 'l'!ds ifl an imports.nt i'actor ·in decre~sing tho amount of the time nead~d to raise tho tempeJ.~atux-e of !a substance. ~th~:r s'l!bstances. Rd'lecticn, t.ransmiesi.on~ and Absorption aro I ill·i.J.st.r~>.ted in figm.. e 9.. I . ~ i/ K i ' ~ ' 1.'i Ref1ect1.on of microwaves :rrom m.eb.llic surfaces occurs in the same :ma11ner that. light :ts l'ElflectGd from. .a mirror., The nwst rF.)fle()ao reflected and not absorbed, the metals do ·not get hot.. The ;:;ides of the micr~:n-m.va ova:n make usa of this property to keep the ro.it':rowaves in the oven cav.t ty., The U.S tharei'or€1;; h.::lat. is rwt produced. Transmission med::i.ums inr;lude glv,.ss, pa:per, ·~.!l..."'t, cerar~.ic tnaterials and plast:.t<;!s,. These mediums are n@ut;;:-e.l or nonpols.r st1bstcmces and are candj.da.ta :materials for use e.s ute,nsils · in th-3 microwave oven. Absorption of microwaves produces heat 'Within a substance,. Water is a vary good abso1•ber of microHaves, and is u.s'9d as a st~J'ldard mecttum for heating and testing purposes~ Foods :rank high as micJ:•owave absorbers since they often contain water. O::llo:r- affects the absorpti<.m of mici'owa.ves. A dark container absorbs more erw1•gy than does a. l..i.ght ·one (18:66). This can be partially explained by the fact that microwaves are electromagnetic and b~have in a manner similar to light rays. A black body can absorb 100 percent of th~ light that falls upon it. .A black pan in an oven will absorb more radiant heat anergy thtU1 a shiny one. 'I'hus, the color of the containers or the medium placad in the microwave oven will affect the degree of lossiness. > + The n~icrowsve oven: The microwav-e oven reprBsents a. f),(~W breakthrough in meal preparation (21:4)~ S&.lss for doru.<,;~stlc mic~row.ava ovens ar~ predicted to b~1 o·~·er one m:l.llion in 1974 (21:15), A microwave oven can ba descrJ..bed as tt ca.vity, u.:n:telly :rectangular in m... oss !>action, into whicm :m:l.t~l·o·~n>.V$!1 ener.gy is fed from a wav-egu.ide,. The m..i.•:;rollave energy is ge:nerated by a vacuum. t ti.be called a. magnet.rcn ( 22: 11)., The typical micro·wave over! can be div:tde<'l into six major componen t A.>: ( .L- 8 ; '12...... -.:."') ... (See Figure 108) 1. The boxltke cavity 'rrhi·ch has metallic 1-ralls. The mim:-oluve energ;;r entering the c9.vlty is 1"€d'le<:,jt.ed· off the \valls until it reaches the load,. Approxi= mate dimensions of domestic ovens a1:•e 14 x 12. x 8 inches., 2. The door which provl.dE>s access to the c.uvi ty :md also confines tha microwave energy~ ). The power supply to eonvert low voltage ll.rie pOi.,..(">l' to the high Yoltages required by the magnetron. 4. The magnetron or rnicrcwava generator ·which is an oscillator capable of converting electrical power into !liicrov;aveno 5. The transmission, or coupling sectior.:, tvhich transfers the microwaves to the av~n (Incl·udes l>Ia.veguide and feed box ). 6. The stirrer whicll distributes the micro-waves in all direction~ to accomplish an even energy distribution in tha cavity. In addition, domestic models used. foJ:- food preparation have several other controls and parts: (1) The timer control mechardsm is extremely important, since the time rather than temperature is indicative of doneness. (2) A vapor duct is provided to emit. vapor and moisture which evaporates from the load. (3) A shelf should be . . ~<'lavas can be re:flected to the load f:rcm. the oven floor.. Sor~e mr>d6ls have trds huilt into the cavity.. The shelves are of :m:tcrowave tr:ms~ parent material such as glass, fiberglass or Pyroceram., Figura 10. Components of a. micrt.'IYiave oven (35~1) (29:10),. Reflected energy may dsmage the magnetron wave generator if the oven is turned or.:: when empty.. Some ovens are specifically des:i.gned so that reflected energy is out of phase and does not harm t.he magnetron wave generator (JO:l). A cooling system using forced air or ci1~culating liquida is needed to cool the fJlectronic CJ)Ulponents.. The design varies with the indi'Vidual manufacturer. Since m.icrcYt•Taves can be injurious to humans under specific eircumst.ances, the Depart.ment of Health, Education and \>Jalfare has sot up pGrformance standards for microwave ovens (42 CFR 78~2.3) (18~26) • To meet these standards, manufacturers have had to give special attention to door seals, door screens, and door-interlocks to keep leakage of microwaves below the minimum required by law., The door-interlocks automatically shut off the power when the door is opened. 22 An automati-c defrosting cycle :ts intervals. The rest period allo1-.rs thE! heat ga:nerated i.r1 th~ outer one and one-half inches of thfJ substarw9 to be conducted imra:rds resulting in a more even heating of the subst.anoec Contim.M.ms lllicrowave energy applied to frozen pr·och.wts results in m:d~sira.ble t.err.perature d:l.ffe:r.ences creating _hot spots w:i th:tn the product. Actual c:ooking begins a.t th~se ur.lpredictable hot spots before the frozen product is completely tha:wed (21:18)., the substance b<3:\.ng heated in the microwave cv0n. The greater the exposed surface area of the substance, the greater the r<.J:ilt:m.nt.. of' evaporation. The vapor eondenses on the cool i:nner surfaces ·~f the oven (18: 91). The US(..; of mioro"~>lave heating for drying various substanc~s is a particularly useful application of microwaves. Since microwaves a~e preferentially abBorbad by the water rather than the solid~ the moisture is heated and drivan off s.s vapor (2):.5?5) ... References to micro"tvave drying "t>rere fo•.u1d- for tha fin.ish-dryin.g of potato chips (.33:12), drying of No.:t'"'l, a seaweed. eaten in JRp&n (2:3:578), drying of flowers ()4), and industrial drying of textiles (27:16)o Microwave drying has several adv~mtages which are as follows: 1. The drying :rate is tremendously increased. 2·. Product deterioration during drying may be reduced or 0 eltminated since the product naed not rise above 212 F. J. A moisture~levali.ng effect is obtained becau,'>e th'i!!' ·substance becomes a less efficiant abso:a-ber of micro- vTaves as dryness takes place, ar;d therefore, the more :moist areas te!'ld to dr·y faster. 4., . The oompact.ness of the nucro~·UJ.ve equipment :ooe.kes it .. ,,..., 1£) expanding the. su:rrounding physical plant ( .;.(: ~) The use of microwave heating for industrial dry'l:"Jg of te:r:t:l.le materials has tha following additional ad~Jantages: 5. As little wicki.ng of liquid water occurs from the center of the material to the suri·ace, the deposition location of dyestuffs or finishing agents· may be better controlled. 6. The fact that w.icrowave heat:i.ng tends to make the moisture content more u,nifonn may elin-..inate the need for e. moisture regain period before further procos~:ing {27:16). The principal drawback is equipmel1t cost and fuel costs (27:16) .. In actual practice, mi<~rowaves :;tre used most economically to rt~-m.ove only the last few percents of moisture, usually the most difficult water to remove v..'ithout damage to the product (23:.587) .. • + Cf:lt-.FfER III PROCEDURE Pilot St.ud;.r bv Autho1: --·- ...... =---...... --~~.... "''""._,.-_ .. -n,,~ A p:t~olimintary series c•f stud:i.es ware card.ed Otlt by the resaarche:..'"' to determine b;.u;ic f\>a.dbility of using the domesti.e rn.i.cro'\>rave oven for drying text1.les and to establish basic pl'CH!eduraJ. tecr.n:tqv.es., Dry· Sfu-n.ple specimens, 15 by 15 inchE1s, 50% polyester e.nd 50% cottc•n, were weighed and wet out. 'I'hey 'h"ere then dried to origJ..:n~l weight in the microwave oven. The results indiceted the fo].J.mrl.ng: 1. Dete~~ination of drynessQ This investigator' 6 sense o:f' touch was sufficient to determine dryness, because the specimens felt dry only when tha original dry weight was establit:.;hed, 2. Specimen holder. A sped.m.en holder was designed and modified to reduce accumulation of znoi.sture in the oven. The ultima.t,e design is shown in Appendix Ae .3. Auxiliary oven materials. (a) A cup of water was placed in the oven as a precautionary measure in CL\Se the specimens to be dtied would not present an adequate load for the oven to preclude damage to the magnetron. It was determined that drying cannot be accomplished with a cup of water in the oven 24 . . sinee too mnch va.po:r :i:s present to be properly Yel'itfJd by the :micl'OWt~ve oven,. (b) A desiccant. w.a::.: placed in the oven to atd in. the remov~l of moisture~ that normally oollected on the cool interior O"'!ell surfaces., It was detert,dned that the disiccant did not improve the drying rate~ 4~ Hot spotting. A hct spot n1anifested itself' as a scorch on the :fabric duri.ng normal oven operation if an attempt was .m~~.de to oYer~dl"Y the fabric.. The area of the hot spot wa.s ahmys in tha s~~e location~ 5. Defrost cycle. The defrost qycle of the oven produced satisfacto~f dry1ng results; the fabric l'e:!!la1.ned cool and no scorching w-aF> observed. Twice the amount of time was requ..i.red to dry fabric u.til:l.f,ing the defrost ~~cle versus the no1~al oven operation. After establishi.ng procedures for drying use of the domestic microwave oven, a variety of textile materials were dried to determine possible fibers and fabrics which could be dried by this method. The results ware as follows: 1. A one-yard sa.'llple of blue, cotton, pinwale corduroy dried satisfactorily. It becrune very hot but dried wrinkle~free and fluffy .. 2. A white cotton terr,y towel took 25.5 minutes to complete~ dry. The towel had crease lines where it had been folded and ha.d a. harsh hand.. The itrv·estigator conclud~,d t.hs:t t.umble cll:·yi:ng of thi~ towe1i.ng 'Would produce more .satisfs.ctox·y resu.lts., )e Two yards of white nylon jersey p:t'esent~Kt :no problem in microwave oven dry:ing., Res·•.llt.s were sat.isfactory.. 4.. Drying E• nylon coil z:l..ppor in the zaic:row!I:'U~ ovel"t 1.\fas a failuYe because the pl.a.stic teeth Ut'.i.dt:a• the tab melted.. 5. Bias tape lias wet on the cardboard wr.ich was folded to allm.r the tape to be at slack tension., The t~p~) :mrl cardboard were towel-blotted dry before complete drying i.n the mlcrowave oven. 'l'he tape shrank seven percent and the folds remained in the tape. In summary; (1) fabrics of light to modium weight d.ri~•d satis factorily, but heavy weight fab-::-.tcs, which absorbed large sno1.mts of moisture, presented more wa.tor to the oven than could be \'ented; (2) i terns having metal co:mponents v-Tould require ext1·eme1¥ caref·Jl position~ ing in the oven to avoid d3maging the sample; (J) the o·V"en must be designed to run with less than a full load so that the reflected energy is out. of phase and does not harm the magnetron wave generator .. ~t Procedure Introduction: A comparative study was employed to determine whether the method of drying (i~e. tumblo dry, microwave oven dry, or room»line dr,y) does significantly affect the dimensional changes which occur in the pz·~shrinking of selected interfacing and underlining fe.brics. • + 'l'est Fa.brics: Afte:t' strr,.veylng the interfam.. ng and underlining fabrics nvatlable dey. These f.ab:dcs include;d o:ne cotton, one rayon~ one polyeuter; two polyester-cotton blends, one rayon-polyest~r blend!! and Ci'W rayon polyester-goat hair blend.. All fabrics were of plain weave construe:twn £.Tbich have the greatest pote12tia.l for shrinkage., The fabrics wen~ white o:r ecru. i11 r.:ol.or to :r.e at-sorption~ Nor>e of the f8hr1.cs required iron:i.ng when s'l.ibjeet to home laundering procedures. Fabric analysis was ca:.cried out using standard test proced~.res., ·rhe results are SUl'I!IMrized on Table ). Test SJ)ec:imens: Test specimens were prepnred for shrinkage detenrdnations fcllow1.ng the 11 Amerie:a.n Assor~iation of Textile Ch£'!1list and Colo:t (AATCC) Test i.>iet.hod 13.5-1973" (1:18.5). Nine test specimens, 15 by 15 inches in size, were cut from each test fabric so that no portion ,-.,f ;.my test specimen lias close:t· than one-tenth the width of ths f'abric from a selvaget cut or torn edg~. Each specimen was coded with a t~,o-digi t id(mtification nu'1ltber. '!'he first C'd.git identified the type of f'~brio, and the second digit identified the specimen within ea<.".h cyp~ .. The specimens were conditioned following the test method, ".American Society for 1'esting and Materials (ASTM) Dl910:4" (2:)52) .. r--·--··· ------·---- ·-··--·------;,~~~-;--·------·------~------~ l'J.BRIC Dl!:S(jR!l'TION OF SELECTED INT)':RFAC:rt!G AND UNDERUNING \\OVEN FABRICS Fabric ~/eight :r-br'i<: I _____'l'ype Color (l??J) I Width :l.n Ot,/•q, yd, J9) ..... ,,.brta Fiber Content -r Pricolinear ·-·---per .Yd. ~ inches (AS1'M D 191°- I La be l ·rnronaation "'---:;;.::::--~ '70'f, Rayon ,5.816 ====J==- I ~o.ru I $1.69 I 2.5 45 6) Machine wa~hable. . 1. ''"'"'"t ,,, ' -- I _... I "'" .... I l ·---~- ----4------·------~ L ---t -- .. ! l'olyoster 1,440 11) (None) 10~% '>~hit. I $l.'t,9 -r-- 4S 'n I '· I '(,.~;::;:;;• I I I Machine wash aed. teaperatur•. 68 --, 2 • .50? 99 Turnbl.. dry. ll-20 I ., I -1 t;otlrtlt I~~ ~~=~t:tton I """ !lang pl:"omptly. '· I I . ),112 69 &4 Wrinkle resiot.u1t. ! . I - -1·, .. ,.,.. --t-1- Drip dry. , I "'"'" ~- I I ~ 1.99) 68 81 Machine •ash, •arm; tuable dr,y; remove promptly. I1=1/J, I ----.- ·, t t_'·" 45 Anti-static,t~ll•'· >• («l-oot ' w; '""''" . I eyclo. I )2; . ----t------Mac.'-ine U•o coo "''""""-'. ""' '" . "'"""'':••• bl., ', ..... '~"''folr••~;,..,., •• 1M • """' ~low,""'''· ·~- '""" I1 l'!v:lerlining SpunRa;ron $1.19 J.0,56 ------,~·. JIl ... ,,., ___ +_::ll.OC"J' Vh~ul-::::-1 I I 6. :Liltert•.,.lng ---- 1----+-- I I _J __ Whlte I 7. Voila tl~::-=-:: I $1.)9 48 1,7:)) 6z 56 Machine wuh, t'Jlllble dry. I ------·-·· ------.---- ______j ~ \ . . rel.ative hund.di ty. Thre~ 10-i:nch gauge marks were d.:rawn pr...r<,.lle1 to the length of the 1cridth of th!i'? speclmtm.. •rhe gauge marks w~ro at least two inches from all edges of the test sptH:dmen ~md fi va i:nohes apart .. Test Methods: The generr..l tE:st pJ:>ocE:du:ra folloved was "'AA'l'CC 'f~st J:1ethod ,.1. J :;;---..~:: ., 9"Jr , n'umensJ.,C•nal. • ~ Ch anges ~n· Au t omatJ.c- · c.r,.om.~ .~r . .aun d cnng· o f Durable Press \•loven or Y.nit Fabri-::s" (1~185). Procedural v-ariations were mad~ in le:under:tng temperatures to be in accord~ncG with the drying prooedUl'e wa.s added.. The laundering and drying cyc.les of tho test were repeated for a total of five laundering and dx-ying t--r,;rc1 stud._v. Exact p<1.:r·.;;:n:wte:rs for th~; washir.g mac1:1ine e.re given in Appendix B.. Procechn"filS rEJcommended by the manufa Table 4. The eondi tiona ~ve.re those most nearly approximating recommended instructions from the fabric manufacturers; if the instructions were not available, condit1.ons "Jere selected from the "AATCC Test Method 1).5-1973" (l:l85)B The "Consumer's C-are Guid~ for Apparel," produced by the Consumer Affairs Co:mmi ttee, American . . . . JO l TABlE 4 l I LATJlliDERING CONDITIONS I FOR SELEcrED INTERFACING AND UNDERLI!-l'ING FABRICS I l I Fabric I Fabric 'no. I type Action Setting Temperature Cycle --...! --, . le !fair Canv~Gentle Cold 2. Underlining Regular Wa:rm (fil?-rnent) .3 .. Batiste- Regular Wann -- I 4. Nus lin Hot I . Regul-:~-= ~ I 5. Underlining Reg11la.r I Warm (filament I I e.nd staple) I ~~- J I I I i 6. UndO< ll~~ng,~ Gentle \tlann interfacing (!Staple) l 7o Vo5.ls Regul-'3-r Warm ______,___ ..]____ I. -- !. ______-----·-·------·------..... ______; Jl App,'J..!:'el ManlU'act:urel"'S Assoc:tatir.m1 -w-1..~.s also t.:l.on of exact cond.it.i.ons for la:~..rr1dering~ Latmdering was done using fu.ll ~;~lte:t· level of the v.m.sh(eJr •. Ballast fabric ·w-as added with the tost speo:lJTI~n t.o obtd.n a four pound load using a IDiniml,h"l1 of ten ballast p:'l.eces pe:r lead. Ballast fabri r: ccmsistt1d of .:36 by )6-~inci-11 hemmed s:nd bl*'a<.~hed cotton· sheeting" Each load received 91 grams of"AATCC Starodard Detergent 124. 11 'I'he washe1.. was allo¥md to proceed automatically th:t'ough the fj.nal sp:i.n cycle.. The load Has rem<.nre~i isnmedia tely at the conclusion cf' the final spin cycle. Spt~cimens w~are h.;-.ndled ·vd.th care to mi~tmize distortion. Three spee)~ans of each fabric type were dried by one of the three drpng prooed1.u·e~H m:ic:rot-rava drying, tumble d....-ying, or room- 1:tns drftng$ Specimens identi.fied by the second di.gi t of l, 2., or 3 of each .fabric were dried in the micro~or.:nre ovene The parameters for the oven are given in Appendix C. Manufa.otu.rer's recon-unended procedures for the l:tse of the oven were followed. Spec;lmens ~;ere stored in a plasti \1 bag upon rall.cval from the washing machine u.ntil they ctmld be dr:!.ad in the microl'rave oven. Dr;.ving was accomplisb6d by pl.ac.ing one specimen, folded into quarters, on the paper specd... "tlen holde~ (See Appendix A,.) The holder and specim~n were placed in the center of the oven floor. 'fte oven was operated on the Defrost Cycle for one and ona-hnlf :m.i.nutes of oven non" time,. The specimen was removed and unfolded after the oven completed the cycle. If the specimen did not feel dry to the touch (a valid pre-tasted indicator of dryness), the .'32 l'TtLS .repli!.n.ted for one-minute Defrost. cYcle intervals until the specimen felt 1.i:ry., N.aximum tir.N requil.•ed to dry any ona specimen 1·1as thl"ee and Spe<:rir<~.::!ns ide:ntifiad by the .second digit of 4, 5, or 6 o.f ~ach · fabric typo and t.he ballast fab:Flc •~er~ placed :tn the automatic · tumble d.ryer. The p8.l"l:UJ\etors for the dryer a::"e giYen in Appendix C.., '!'he 1(.)ad 'WfJ.S renwved immed1.ate1y after the d.ryor cycle uas eomp1eted (20 minutes). Specimens identified by the second digit of 7, 8, or 9 were hung on the clothes line r~.ck by 't\'l·o adjacent corrlers wi. th the fabric 1ength in the vertical dire hang until dry (two h01rt~s) in the rlt" conditioned labo:ra.tol Collection and EYA.lnati·::>n c•f D:>.ta. ··---- . _.._.... -~..._...... ,._,. All test specimr:ms wcrr·~ condi.. tic ned after the first and fifth 1.aundering &"ld dr-yiug e.ycles folJcwing the method stated intrAS'I'l~ Dl910-4 ''(2:.3.52). Room conditions l'.rere 69°F, and 34,% relative humidity after the first laundering and drying cycle. Room conditions were 72°F. and 35% relative hum:i.d'ity after the fifth lai.h"'ldering and dry:l.ng cycle., Shrinkage was calcmlated. after the first and fifth laundering and drying qycles. Each bpecimen was measured without tension on a flat, smooth, horizontal su~face. Measurements were taken and recorded to the nearest 0.005 inch for the distance between each set of gauge . . a plus sign,. 'l'ha follo1 Original vlidth - Final \ Original Length ~· Final Length _:-..: L<·mgth Shr:l.nke.ge 'I'he average shrinkage oi' both length and w1.dt.h was c&.loulated and charted for thf::J results after the fi:t·st ~ad fifth test. The following formulas ~m1•e used., Average -vddth shrinka.g~J f"or like t'r.;.brlc ci:::'ied in B. like ::: __.,-._~.,....~--~,_... ~....,...--- marL."ler. 3 Average length shrinkage for Length shr:i.nb::.ga of sample 1-!·2·+J like fabric dried in a like::---·~·~---~-~-.-~ mannere J The average percent shrinkage of both length and width W&..s calcu- lated to the nearest 0.1 percent after the first and fifth te~t.. 'rha results were charted., 'I'he fo!.lo'l'rirAg formulas ,.;era used. Average length shrinkage ~----- X 100 %A:ver~ga lengthwise shdnkuge Orig-ln.al length Average width sh1~nkage ------x 100 "" %Average 1<:"idthw.lse shrinkage Original width The area shrinkage of. each specimen \.:Yas calculated after the first a.n.d fifth tosts.. !'he .following formula was used. ( Original length. x original width) =Area shrinkage (sq. in.) . - (Final length x Final vddth) An "F" test of variance was conducted on the area shrinkage after the first and fifth test. J4 ,- -·-·-·----·------·· 1 1 The average area shrinkage was calculated and charted for the I results after the first and .fifth test. The following formula was j used. I I Average area shrinkage for A~ea shrinkage for sample 1+2+3 like fabric dried in a like = ------manner. I I I I I I ' I 1 ! j L... ·-·---·------·--·------·------··---·----·-----· ·------·----·---·------·--·-··------· . . RESULTS JJm OBSERVK£IONS The basic objective of this study was to ascertain wh~kher the method cf ciry:\ng (t. a,., tlUll.ble dcye:r, I:'.i.crowave oven, or 1•oo:m- line dry) cioas sig:nificantly affect the dimension&l changes which occur during tha preshrinking of selected inter·f~.cing .and underli'ning fabrics. Nine te::;t speci.mems were made from each of seven d:i.ffe.rent. fabrics.. Eg,ch group of l.'l.i.ne specimens ua.s washed together through five lattndering.s according to procedures typical of tho~e used in the home for pr,::,shri:nking purposes and according to accepted test procedura·s~ Thre':> specimens of each group were dried by ems of the three dry:i.ng pro(mduree--,-micrownva oven, tumble dryer, or room~.line dey. Shrinkage was dsterrrrl.ned after the :first and fifth laundering al'ld d..'"'Yirtg cycles. The :rueasured test :res1.1.lts which are given in Append:tx D are to the nearest 0.005 inch. An increase in size was expressed by the use of a plus sign. Figure 11 illustrate~ the average shrinkage and avero~tge percent shrinkage for the lengthwise shrinkage. Figure 12 illustrates the average shrinkage and average percent shrinkage for the widthwise shrinkage. 35 Average Lengthwise Shrinkage in Inches • • • • • • ...... ,• • • • • • 0 0 1-' 1-' 1\) N \.,.) ~ \.1\ \.1\ \.1\ \.1\ \.1\ \.1\ & \Jl 1-J .....; Hair 01-'' ><~ Canvas 11 I-'® 0 --~ ~· 1-' -~~ a~ t"' ·-un d er_,_,_n-,~ ;:r p. ing (fil-l (No shrinkage) ·~ ~ ament) (II '1 f3.~ s (D m~ 1-'m Batist~ ~l'l"~j:('ij"~/Z ~ ' ·.c:~· !t> [jq ~~~ ~~~ .... ~·TI1fl u; ~ ~ 'xj ':&!:/%@'~~~~ t-1 f.ll, 11> ~·;i(.,." 'I':~ 'tT"'~~'te'' -~ '("'A • , j'> 1"<;3' m ::J' cr u li ~. . '~,.. ..,;". ,. " ·"·· ,.~" ··. n "'yA .y.., r.•_...... ·~ ~-~J t'1tts n ~,.,.,~~ .~'<¢\~..... '"'~~ "'"~'"''·cJ.:..'<>ii-0\.~;;::_,._ ,.~'"lt.~~,~.:.ft. .• ,..,..,:\.""' ~J">..,scf'j!fill fr..s 0 ~-'' 1-1· .f.!il !II H IIlli II II HI. I H :::::::::::::= ~ ~o LilllillllllllllllllllliH= g~~ ~~~~(~~=~~~~ P' p. ~mAUt anr~ ;~~'l.,,,.. .. ~ ..~);;:~fl>.'\,·">2\d•.'\,:~.\ ..~"c •..•..• _..1L•, ~ ~ ;t:~~~ie> ~-~~~ lfli IIIII ll \H\HlHH\~ g·J~ Und~r?::tn- ?'f2~~~ :1 tr- ing/ In- ~,.~"·"'"''"'"'"'"..;I:'\'1'l\~'\"{''"~<'~r"\'C{'!J'!'JJ'4??:~; ~· ,~ t ,~;r a dng ull!'lnlr(lt!HtiYtlr1i.li'rr~f::~:~~ 111 (..) ; g. P~ tri'J~~ fJ.... '"rJ 't • .., ~~!>~;~~~).'?.f?:~;~~~~;:j_,.-;,(1?~,;#' .J'--; :'-.,.., i{OJ. .1..e n~~'.'h-...:;il;.-..." 9( . . Average Widthwise Shrinkage in Inches • • • • • .. • • • • 0 0 ._. •N •N \.,.) \.,.) ~ ~ \.11 \.11 \.11 ~ \.11 \.11 \.11 \.11 ~~ aq 1-" :::; o•; Hair >< (b CB.nvas i-'~ 0"' ~ 1::$> g.~ '1 til Ill "Ci(JQ ing (fil- it> Ill 8ll'lent) f?.. ~ s [:1, (liP., :su1 ,.1-::.r B-;a t•1.s t e "4;t; ~ !.J. H;letl c+ at it> '1111'""1 ::;'IU . . _ ...P~ff, ,J , •• ~ !'1usl1.n ~~~{{~~~~"'-~"'~-""~ ..,,,, ·•r·~--·.'XZ·'""' <.<~:~.,«~'\\'!' (.,•~ ~ () ~ :·~:\_". \~\ !-\~\:>~:\ \ "}~'!'\~{>."0\~\,_\\\,~"'.f-\,. \."\. "\ \..;:i'i').~? r .• '#. ~ ~· ~ ~ ~ 1T1rrnnrrrrnnn rnn mrrNn u o.. ~ m Underlil."i_ll §~ ~~n~r;~d~ .~-"" ('/) ~,i Undorlin- 7d{~%f{fi@J ''1 "'i , ·. "-'·· ", • }-J<~ ina/CJ In- ~~:;<;c,: " r-~ c+ ~ c+ jj! j i'!'" ;:4~.. Area shrinkage is gi ve11. 1.11 Appendix E for each specim€n .:~fter ens and five test cycles. These data -..;are used for the fi}i":n test analysis of variance :t''-'r the test of signif'ica.n.ce of th,., data relative to the d::l.fffH'ence betvJaen area shrinkage ~)f' sp(3d.IJ.ens dried b-y the different xnethods as Nmpa.rad to differences of area shrinkage of spef.;:i..Ittens within each fabric type. The "fi'" test results are shom1 in Tables 5 and 6 for t«;lsts ctmductf!d after one and fi va laundering and drying cycles., These, results -indit~ate that there is a significant diffarG-nce between the dimensional cha.nges which occu.r duri.ng the presh:!:'inking of selected :tnt~1rfacing a.nd underlirling fabrics ·...-hen dried by turnbJ.e dryer! microwave oven, or room-line dry .. The working hypothesis is accepted as stated; the null hypothesi.s i.s rejected as stated. Figure 13 lllustr&tes average area shrinkage data. Observations .certain observations were noticed by the :rea.earcher during the course of this study. The underlining fab~lc of 100% po~yester filament yarn had the least amount cf shrinkage.. This was expected b!'.::lCause }1olyester has the least amount of swelling eapabili ties of all the fibers used. 'l'vro other .fabrics which shrank vez:y little were those composed of 65~ polyester and J5~ cotton* However, the voile had mora shrinkage than the batist<;.;.. It was expected that the batiste with greater cover factor and more i.nterlacings wou.ld have greater shrinkage. The researcher's theory of this apparent discrepancy is that perhaps the manufacturer did a More complete preshrink J9 ~------1 I I i I TABLE 5 Source of Variance ss elf HS I Oommited IC"Ci te:don "F" :'F11 ~~-5 .. Ol r=- . -- I Beb1een cells J54 .. .5o 20 17.70 j 29.5.,00 F 1*82 2 .. 35 Between rows 2,.10 2 1.05 17.50 3.22 5.15 (drying method) I Between columns 349.3.5 6 I .58.20 970.00 2.)2 ) .. 26 (fabric type) I I Interaction J.,lO 12 .. 26 4 .. 30 1.99 2.64 within cells 2.).1-£31 42 .06 (error) Total J.57 .. 0J 62 I TABLE 6 "F" TABLE AF'J.'ER :E''I?'TH TEST CYCLE Sourco o£ Va:dancal--:S .r-fS Computed Criterion nFJ• I!Fn .05 .01 Between cells 370.97 zo 1 1.82 2.35 Between rows .5.8 0 2 2.90 I 13.,80 ).22 5.15 (drying method) Between. columns ).56.95 6 ' 59.50 28).00 2.)2 ).26 (fabric type) Interaction 8,.20 ].2· .69 ).29 1.99 2.-64 I I 1-Ji thin cells 8.89 42 .21 I I (error)-j...--To_t_a_._l_...._-+-~J-'?~9.~8,...0,-+--6-::-2 ...... _ --,1----- I ---- J Average Area Shrinkage in Square Inches 0 1--' N \A) ..(::" \.J\ ()'\ ""' co ~~ c+(lq H . Gl ~ a1.r '1 'i {II Canvas :,i..,.. '11vJ til • c+ Under f.l,(b~ ~ lining i"$ H; 1\) (fila 1-1· iJ'~ ment) 'i i-'!l'J~= ~r:: ~ ::1 fJl B..,.. te · ~s- !Jl .,l, ! o..(\') 'i .. s . I "1 \-'• 1 l~l· ~ ~~ fr ~Jk ,...~{ .e:- '1. ~~.~~~4'@.~#~.%~~~-:,,~t.ll·· ·· 0;:::(~. --·)'\A.··"'-.~-.;--·~"'\-.>.· •.. _ .• ,.'-'·., ~---- '\ , __ ,_.,.. ._.,~ -~F-... ~~ ; ~~ • .. \wl... n !HlTIIItll~nnlfr rn rnlHTlfll r~lfni nn~ ~~ b =d l1rldor~- ~ ,... -· · ~/:r~z~"%%{(~:0/1?'~~/,;?//,/w~~, ~ ~~ ,., J;:t::ling ~«~¥~{~:&~·~.(~~{~,<<0'~((~J>~,i«:;(:~~;:1,. ~-. "i{~ ~; :· i.T~d~r~ 1 ~~;~~~3'%~~;?;{,%%?:';%~~~~ 1 Iltk:!'r·.g; Al!;'i,'Y... ·~ 1~ ~::t:~~;~:;;~~~~;:~),~~::~~:~-.:~·i~:~~~::?~::s::·:~':~;:~~:~~~;.£·".·"'"'"· "". €:; " '" - ill!'! l \!'I Ill i pi II t l f' '!! f; iII I! I I! i! IiI I! I I;;~·-"-._:.__ 61 facing ~u!idil !dl1 li~HlniLi\!ll\l;,\\\\1\H:_-...::::: w I fj ~.?~~~~15::/?~~~~~~~~~~~~~ . t'.:"'~·:;.\:\~;::\\~~:: ~'::<.~::,.<.>:/.:y:~~~ I. Voi l (! e~ "'''- ,,,:;,,·~'-'·'-'-''·'.;,ct.. 'c.. _,,·_,-'}.. >? . ·...----.. ------"""-~ l '"ZJ ""' t+ i-''· ~+ ~ I \I) ~l (i) !-<) fJ) (./l 'Jl >-1· ("i- ct- cr- tz~ ~ . I aq I; Micro~>r&.Y~~ <"Pl".m~'l/:'::;~~~'Y'4~'"'"-'\ m I1 ~ ~·vv "( • ";>'; ' .,,,. rJ j 1 'h.Jr,'hl~' "i'\ ,. ·:c""·'~ i ... tJro.,.~ ·-> a··~-'-~ .. vr-,·r- ·--'"" !\.· ··•.,'A,'\;;~:_1L-~"')'~~ u., j Jtoom.aline drv iiI ill;:::::::::-..::: I f u l!iHi-= ---··--~-----.-...... ---·----~- Oil . . "'l{;ile fabric~ Both of these f&brics had less tha.'"l t>JO pen·cent goods. The hair canvA.s goat hair had much greater hmgtlr•d.se shrinY~tlge tha:.."l widthtvise shrl.nka:ge. The filling yarns werw coarsor than t.he wa:."ll y.;n•ns.. In the case of :microwave oven drying, the tabr:l..c actually inc:t'II:l2.Sed in 1-.ri.dth so some of the le;ngthwi.se slr::'inkage was probably due tc1 a ex-imp adjust.= r~ent. P0rh.?.ps the researcher's folding snd handling of this fabrlc caused this t-o ha:ppen. '£he• fabric did not feel or appear felted,. Average area shrinkage was less th~n two percent. The lOO% cotton muslin and the lOO)t spun viscose rayon underUning/ interfacing (staple) fabrj~ shrank about three pe~·cent in both length and width~ Evidently, the heat of the dryer and microwave oven ,assisted in the rEmlcval of w:rin.kles since spacir11ens dried by these processes were qu,ite wr1.nkle-f.ree.. The rayon, U.ne- dried specimens were especially ,.1rinkled. One cotton specimen dried in the Ilti.cro;.lf.ave oven became very slightly scorched~ The specimens ma.de :fror11 50~ rayon, J2% polyester, and 18% high modulus rayon, underlining (filament e.nd staple) fabric had the greatest shrinkage. The widthwise average shrinkage WB:S· 4.'7 percent, and the lengthwise shrinkage was approximately 2.75 percent. It appears likely to the researcher that the 50'% regular rayon.is the weft yarn and strains imposed during the weaving process may have caused greater than expected relaxation shrinkage. After the fifth washing and drying <:.fcl,.,, the fabx1.o exhibited less sb.rir1kage t.han. after the first. l'rash:i.ng and drying cycles" The researchert s theory for th:?_r; oceu.rrenca ;.ran that this filbrlc raw;led considerably, u.r.;d perhaps th{:;, i:inta:ng1ement of the raveled th.:reads eaused some crimp adjtlst.me:nt that was later recovered. Again the B.na dried specimens showed considerrabzy mo:re 'Wl·inlr.ling than cl:td thos!:)j specimens <-lried by the other tuo methods .. The ntic:z'.:Yvlava oven drying procedure dld. produce lt~ss shr:b:tkage than the other two methods of drying. In genera.l, the m.i Gi.'O>faVe ovor:. shrinkage was 0 to 1 percent less. After five laundering and d.r;yi.ng - cycies, the difference became less. . . > • CHAPTER V CONCLUSIONS AND REC0}1MENDATIONS Thera is a s1.gn:lf"icant difference between the r.ii.'llens:lon:tl changes which occur during the preshrinld.ng of selected interfacing and underlining Tabrics when d-ried by tumble dryer, m:'L.c:rm~a-,t\S oven ov,,m to b lining fabrics because less shrinking is produ<;ed. The residu.i.> shrinkage remaining in the fabric D'dght later cause a fitting pl~oblem for the consumer. In addition, hot spots could occur in ndcrowav::. oven drying and cause permanent damage to the fabri•J rendering the fabric useless. If a cOnsumer j_ntend.s to wash the garrnent after home con struction o.f suc..h garment, the author recommends that all the notions and the apparel fabrics are to be laundered in a domestic washing machine and dried in the domestic dryer or on a line before the ~onsumer begins to se·,. everi with manufactured preshrunk fabric. Further study is not recommended at this time· for domestic microwave ovens to be used in the dr;y"ing of fabrics., However, if future developments give more control of microwave energy, or if a tumble dryer using microwaves is developed, a similar study could be conducted to determine if these findings could be reversed. ,---·------· ---·-·-. ·----· . ------·-· ·------·· ------·~------··---·----·-~------·------·------··· 1 SELEG~ED BIBLIOGRAPHY I I I I I I I I i I ! . I 1 I I I I I I I '------.------_---··--·------·--··--"··----.. ----.---.----·------"---- SEUi:C'l'F;D BIBUOG.Fu\PHI BOORS 1.. Junsrlca.:n AssDa.:l.r-:.ticm of Textile Chemists snd Color:ist;<:;., AATCC 7.'e•.'!hnical Hanue.l. Vol .. L~9, N.. C. z ~C:in P:"sso~:l.o'nof 'rextile C.~ert'.ist.s and Colc,rist-s, 19"7'3. 2. Amer:t,,;.fu1 Society for· TesUng ;md M:aterials. }.-E,.fJ.U..9-l B~,o ls... £.L~J'N _§~::.:1!!.S~~ u Philadelphia: Americs.n Society for Testing Hater:i.als~ 19?1.- 4. Htl.J.l, l~~ ~T., 'I'extile Fi_rg._~b-in_g. )rd ed. NavT York: A.>nerican Elsevier Publishing (',o .. , Inc .. , 1966., Hamby, 6. Hearle, J. ~'1. s. ; Grosbel~g, P. ; a.nd Backer, S .. Structural ?v!ech;.11i cs <:Lf.' F:\.oers. Yarns 1 .,:~.ct fu~ .. NErw 'Yo:ck: "1Jiley..:fn~~~ilCi0''.f969~ Hearle, J. W. s., and Peter··c. , R.. R. Fibr~ StrD-.~-:~u::-'e,. Vc1e I. Hanchest&r: Butterwortfi&co:-'ltdo and the 'fextila Institute, 1963. 8. Joseph, Marjory Lo Int:roductor.:v Text:ila Sutenee. New York, s;n~iscc: Holt;-fiii1ah.art and ~unston, In~., 1966. 9.· Lord, F .. R., and Mohamed~ M. H. \ve..£Enf£.l C£nversio~ Yarn to Fabrice 1.fa.tford Hertsr England: Merrow-"P\i.b"iishing Co. Ltd., 1973. 11. McCall's S0wing Book~ Hew Ycrk: Ral."1do:m House, 1968. 12. Meredith, R., and Hearle, J. W. s. Physical t:f~2.St~_of Invest~atin[.,.!~!!-il~. New York: Interscience Publishers, Inc~, 1959. 4.5 li.~.. Hr.n:•ton, Y.l •. E., 1 ~t>-'!d Hearle, J. W. S~ J:l~'0-'?~E.£1?!:.;1'ties of '!'extile Fibel"J,. Nanchester~ Butte:t'worth & o;:-·m_-;--ru,d t.heTextile Instltutey 1962. 15. Pott-z.l', fit .. David, s.nd Corbman, Bernard P • .Fabric. Jrd ed.. San F'r.anc(Lscoz BoOkComps.ny, Inc .. , 1960 .. 17. T:r-otmans E. T. Jr.tetng ~Efl-~~r:£ca~~~~E~'?.O~L..?.f Textile Fibres. Li-th ed.~ Lcndon~ C.l:larles GriJfin&O-;·;···Ltd4, 1910 .. 18.. Van Zante, Helen J.. The H::'u:::ro'l'raYe (P7en. Bostom Houghton l1if'f:I:inojffi})B:njr, -19',7)., 19. 20. PROCEEDINGS 21. Los Angeles Home Econom:lsts in Business. O~~nt ~~en~s in~um?.!' al1.£_j£mm~~ ~ti2.r.~e Ovens., iJJs Ang~les 9 Calif., 19'?3 .. 22.. New York State College of Human Ecology.· Consumer l1icrouave Oven Systems Confe:ce~.. Ithaca., ifewYork.~~~l9?o:-··- 2J.. Scb.iffma.l'l, Robert F. 11 l,!icrowave Food Processing: A New Frontier·..," ll!i!~LJEt~~:~,E.g_re~ ,E.o_£sL_,- S!.'l~~r;.se and .J'ech[i<>,},!~}::J.'oc:_e~dings., V.Jashingtor1, D. c. Aug., 19'?0., ARTICLES IN JOURNALS OR M.i\GAZI1~ 24. Abbott, N• •].., ; Knoury, It"'.; and Barish, L. "The Mechanism of Fabric Shrinkage: The Role of FJ.bre Swelling." The Journal of the Textile Institute. Vol .. .5.5,1964, Tlll7"- 25. "Dimensional Stability Discussed at London Conference. u Textile Month. May,l972. 8)-84, 88. BUT.....LE'l'INS ~~ s _£i_£,J~L::;.~.£~lJ::J2._Q;~.2~1Ji.. Microwave Energy Ap; 30. Fa\c!~J~~ ?~~}2£t!Js_.M~2}:.~Lgl~~ctron~.. Thenuador. LoB Angeles, Calif .. )2 .. JJ. )4. 35. Olson, Wanda and Olson, Robert.. ,?e~,!},S and Usin.E_ a PortablfJ Microwave Oven" Agricultural Extension Service, University of .Minnesota. H. E. Fam.ly Living No... 29~19?2. PERSO.NAL INTERVIEW .36 .• Pardo, Clay E. Western Regional La.bora.tory, U.S.D.A. April 14, 1974., • . . r--~----····--~-~-----~------~------·-··------~~------~------~------~------"'""! I i I 1 I I I ! I I APPENDIXFS I I I I I I i i !I I i i I I I I I i I l ·~--.--. -.------~------~------·------1 48 APPENDIX A A seven-inch by on (See Ii'igure Fi.gure A-1. The roow.ining portion of the paper plate was inverted. A second paper plate, normal side up, was placed on top of the inverted paper plate.. (See Figure A-2.) tlr,.---· S_oeci.men ~ --7 Paper plates <)(' >-/---_---~-r-- ---"'"'--....:....----~~~~~~-\....::.....-~-· _._ tE-- Oven floor Figure A-2. Specimen Holder. 4-9 . . ~~------~-----~ -- ~ -----·-- --·-----~- . ---- ··--· --- - ·------~-- .... ·------·------·-----~--- ... - - - ··----··· --··· ------·-- ! APPENDIX B AUTOMATIC WASHING l'flACHINE OPERA'l'ING PARAMETERS . ------·--r-·------.. Setting Conditions Regular Action Agitator speed: 6J beats per ro.inuteo vlashing time: l2 minutos. Spin speed.: 618 rpm Final spin time: 4t :m..i..nutes ~------~--+---~--~------~ I Gentle Action 1 Ag:tta.tor speedt 42 beats par I 1 nrl.nute. Washing time: 5 minutes. Ii I Spin speed: 412 rpn. I Flnal spin time: 4! mlnutes .. I r---~------+--·------~ \ ¥ '·1 t I Cold Qrcle t:.?°F-u... v-.a.s h . wa. er,. I 62oF. runse. water. ! r-----~------r------~ I War.a1 Cycle l0~!5°F. Wash water. I 62±5°F .. Rinse water. I l 135:)~0 F. Wash water. Hot c:rele · I I. 100~5°F. Rinse water. 1 I· l__- -~ ------·------~J ,------1 I ! I J I I I- APPENDIX C I _J DRYING APPARATUS PARAME·rF.RS I I I i I Apparatus Conditions = Automatic Tumble Dryer Controlled load "PermanentPress" Cycle temperature while drying. Cool-down c-_ycle of 5 w.in'J.tes whiie tumbling ~"ithout heat w}len drying is complete. Automatic shut off at end of cooling period. Microwave Oven Power Source: 12.0 volts AC 60 cycle. Power ~ltput: 600 watts. -Automatic Defrost qy-cle: Power automatically turned ·on and off at)O-secondintervals •. Style: Counter type without browning unit. i I \ I ! I I I I ---·--~------~------~J 51 ------~---- -~------·-~ ------~------·- ·-- ---~ ------~------·------1 AFPE!fa.ti D I D!liE.'lSlO!IAL Cll.ANGES OF SELEcrED FABRICS AFTER LAUNDERING ! t DRI!!.D Ul'i!ZR THP.EE CONillTIOliS r--F-a_b_rc-le---t---Oryi--n-g---.--1-0_"_x-~~-~Br _One L·lUr.d_s_ri_n_g __-_-~,L--~-t-e-r-~-- _v_e_U.-undel"ings ~ type Condition I Spodmsn No. umgtn>ilse I Ridt.n\iise I' Lengthvi~e _j ;..'idtnWi.:e F======f======:=b: (inc:hes) (inches} (:inches) ~inches) 1. Hair Mi.erovave ov:n~--ll____ - .05 ·-:.os .15 . . . - +.05 Canvas - J2 .0.5 +.05 f .15 ... os i 1 lJ .os +.o5 .1s ... o5 i Tum bl dryor 14 1 0 15 05 . I . . . I " 15 .os .o .1 .os i 16 .os .o 1" .05 ·- t Ro011.-llne 17 .l .o ..25 - ;o 18 .1. .o .25 .o 19 .l .o .25 .os z. Under- Mi.erowaTo oven 21 .o .o .o .05 lining 22 .o .o .o .os (filAment) 2J .o .o .o .o I I Tumble dryer 24 .005 .o .o .os I 25 .o .oos .o .05 26 .o .o .o .05 I ftoom-llne 2? .o .o .o .025 2B .o .o .o .o I 29 -· .o .o .o .05 J. Batiste Microwave oven Jl I e05 .o .05 .o J2 .05 .a .os ' .o :.n .05 .o .05 .o Tumble dryer Jl+ .o .o .o .05 JS .05 .os .os .os J6 .05 .o .os .o Ro=-line J7 .o_s .o .05 .o J8 .os .oos .os -. .25 J9 • 05 . .o • 05 .o 4.· Muslin ,...icrowave ovom 41 .2 .25 .225 .2:5 ·- 42 .2 .27 .25 .J 43 .2 .25 .225 .275 J Tumble dryer 4lJ. .2 .) .25 .J 45 .2 ·.; .zs .J 45 .2. .27. .25 .J Ro=-line 47 .17 ~ .27 .225 .J 43 .2 .27 .2.5 ,275 • 49 .2 .27 .zs .25 5. Under- Mierowave oven 51 .17 .45 .25 .4 lining 52 .1.7 .45 .275 .5 (filamMt zo; 53 .2 .45 . ~ .:ws & ..-b.plo) Tul:lble dr.ver 54 .2 .1~5 .) .45 5.5 .z .5 .J .475 56 .2 .45 .)5 1 .45 .Room-line 57 .2 .5 .25 .5 I ·58 .2 .5 - .25 .5 I 59 .. 1? .s .25 .5 6. Un:ier- Nierowav£~~ o'Ven 61 .2 .2 .25 .2 lining/ 62 .2 .2 .225 .15 lnt..:;:-• 6J .15 .15 .2 .2 I facing Tumble dry"'r 64 .25 .275 .) .J5 (staple) 65 .2 .25 .275 .1!:15 66 .2 .25 .275 .J Room-line 67 .2 .) .J .)5 I 68 .2 .2.5 .2 .)5 69 .2.5 .) .) .) 7. Voile Mierowave ov.m 71' .iY/5 .1 .15 .15 72 .1 I .1 .175 .2 73 .l .l .175 .15 I Tumble dryer 74 .l .l .175 .2 , I 75 .l .1 .1; .2 76 .05 .1 .2 .2 Room-line 17 .1 . .1. .15 .1 78 .l .1 .15 .15 79 .1 .1 .15 oL ' I I L •.. ·····--- .... -· ··------· ------~· -·· . -·· ·------~- --·------J .52 r---·--·-·------·-··· ····---- -·--·-····--·--··-·-·-.. ------·------·---- · .. ·------...... -.-- .. -----·------·-...... ------·-·-· ·l I APPENDIX E ! I .A.REA SHRINKAGE AFTER ONE AND FIVE LAUNDERING I AND DRYING CYCU."'S OF SELEC'TED FA.BRICS I ·--· Fabr:l.c Drying 10~· X 1011 Shrinkage Shrinkage j~ Type Conditions Specimen No. after one after .5 test. tests. (sq. in.) (sq. in.) ; - --f--· .. i l 1. Hair Y.d.crowave oven 11 - 1.0 canvas 12 - 1.0 13 - 1 .. 0 Tmnbla dryer 14 1.0 2.0 I 15 .. 5 1.5 I 16 • .5 2.0 I Room-B .. na 17 1.0 2.5 18 I 1.0 2• .5 I 19 1.0 3.0 ! 2. Under- Hicrowave oven 21 - .s 1 li..ning 22 .s I - (filament) 2.3 - - Tumble dryer I 24 - .s II 25 - .5 26 ~ .. 5 Rooro.-li ne 27 - .J I 28 - - I 29 - .s I I ! J. Batiste :t-tl..crcwave oven Jl ..5 .. 5 I I J2 • .5 • .5 I 33 .5 .5 Tumble dryer i )4 I I I - .s i I J5 1.0 ~1 l j ! I )6 .5 .5 I I I I Room-line I 37 .5 .,,5 :38 .5 J.O 39 .s • .5 I II ! i 4. Muslin Microwave oven 41 4 • .5 4.7 42 4 .. 6 .5 .. 4 I 4J 4.5 s.o I Tumble< dryer 44 s.o 5.4 ' 45 .5.0 .5.4 46 4.6 5.4 1 Room-line 47 4.4 .5.2 Ii 48 4.6 5.2 l 49 4.6 4.9 i 1 ·--.. ·------~-.! 54 ,---··--·--···---·---·---···------.. ·------···--··-·-·--·-·--····--·-··-··---·-----·----·---·- -·------~ ! ! I i I .A.. REA SHRINKAGE AFTER ONE AND FIVE Lf.I.U1IDER1NG ! 1 I I AND DRYING CYCLF..S OF SELEC!ED FABHICS (CDNTINUED) I ! i i --.-· ! ' ; Fabric Drying -10" X 10" Shrinkage Shrinkage ' 'I'ype Conditions Spedmen No .. after one tLfter 5 i I test. tests. ! (sq. :tn.) .(sq. in.) - ··- : 5. Under- Hicrowa.ve oven 51 6.1 6.4 lining 52 6.1 I 7.6 (filament 53 6.4 6.2 & staple) 'l'urnble dryer 54 6.4 7.4 55 6.9 7.6 56 6.4 7.8 Room-line 57 6 .. 9 7.4 58 6.9 7.4 59 6.6 7.4 I . I :6· Under- ¥..icro-wave oven 61 4.0 4.... " lining/ 62 4 .. 0 3.7 I I. Inter- 6) ).0 4-.o I Tumble dryer 6.. 4 l' facing I 64 5.2. I I I (staple) I 65 4.5 5.4 ·I 66 4.5 5.. 7 . Room-lir1e 67 l 5.0 6.4 68 I 4.5 5.4 69 5.4 5.9 I 17. Voile Y.dcrowave oven 71 1.7 ).0 72 I z.o ).7 I - I 7J 2.0 ).2 TU<'llble dr