JOURNAL OF SCIENCE & TECHNOLOGY • No. 94 - 2013
STUDY ON C R E E P AND C R E E P R E C O V E R Y B E H A V I O U R O F K N I T T E D FABRICS NGHIEN C i r u HIEN TUONG RAO VA PHUC HOI RAO CUA VAI DET KIM
Chu Dieu Huong Dam Thi Huyen
Hanoi University of Science and Technology Hung Yen University of Technology and Education Received Januaiy 04,2013; accepted April 01,2013
ABSTRACT
In using, the fabnes and the garment products are deformed by loading force, which is usually lower than broken strength. Creep is a deformation commonly seen in fabrics and garments. This paper will refer to investigate the creep and creep recovery phenomenon of knitted fabnes which are widely used in Vietnam. Three commonly weft knitted fabrics in Vietnam are Single, Rib 1x1 and Interlock were examined on this research The cotton yarn Ne40 has been used for all investigated knitted fabnes Five values of loop length In knitting have been examined for every kind of fabrics knitted which are 352, 362, 372. 382, 392. 413, 428. 443, 458. 473: 343. 353. 363. 373, 383 (mm/IOQ stitchs) for single jersey, rib 1x1 and tntedock cotton knitted fabircs. respectivly. it was found that the creep deformation of single and interlock ts tend to direct proportional with the their loop length while the creep recovery of these two fabricd is inverse propodtonnal with their loop length. The creep atid creep recovery of rib fabric changes without any regular but the rib fabric with average of loop lengtti (443 mm/100 stitchs) is best In creep and creep recovery. This rib fabric is most stability in dimension and in extension, which has been reported in two our other research [5],[6J.
Keywords' knitted fabric, creep, creep recovery
Trong qua trinh su- dung, vai va cdc san phim may m^c thw&ng bi biSn d^ng khi chju t^c di^ng cua ngo^i lue, cac It/c nay thwang nho hon ngudng k6o ddt cua vai Rao Id hi$n tifpng thut/ng xiy ra vai vai va cdc sdn pham may m$c Bai bdo ndy khdo sdt hi$n tu^ng rao vd phpc hdi rdo cua cdc tog/
vai det kim, la loai vat du'oc sCr dung khd ph6 bien & Vipt nam. Ba lo^i vat d^t kim thdng dung (m^t mat phai, rib vd vdi tntedock) dwpc si> dpng trong nghiin ci>u ndy. SQI cotton cht s6 40/1 dupv dOng cho ca ba loai vai fvldi loai vdi ducfc det vdi 5 mCrc chidu dat vdng spi khdc nhau: 352, 362, 372, 382, 392 (mm/100 vong spi) ddi vai vat mot m$t phai, 413. 428, 443. 458. 473 (mm/100 vdng sai) dSi vin vai hb va 343, 353. 363, 373. 383 (mm/100 stitchs) d6i v&i vai interlock Kit qua cho thiy biin d^ng rao cua val_ mot mdt phdi va cua vdt tntedock c6 xu hw&ng ty 1$ thu$n v&i chiiu ddi vdng sai trong khi SLT phijc hdi rao ciJa hai lopl vat ndy lai cd xu hu&ng ty 1$ nghich v&i chieu ddi vdng s<?i. Si/ bien dg/ig rdo vd phpc hdi rao ciHa vai rib khdng tudn theo qui lu$t, nhwng lopi vai nb c6 mwc chiiu ddt vdng spt Id 443 mm/100 vdng sp-; cd khd nang phpc hii rdo tdt nhit theo ca hai hw&ng dpc vd ngang. Diy cQng la loai vdi rib cd dp dn dtnh kich thw&c vd dd gidn tit nhit nhw da bdo cdo trong hai nghidn ciiu trw&c ddy cua chung tdl [51, [61
1. INTRODUCTION during body motion. The loss of elasticity Knitted fabrics from cotton are very ^"'"'"8 " ' ^ ' ' °"^ °^ * ^ "^^^^ ™ P ° ^ * popular in clothing industry. Dimensional Problems that could affect the long-term properties of this category of knitted fabric is reliability of knitted garments such as widely affected by external applied forces that underwear and sportswear [1].
could involve permanent deformations. At present, there is no any standard or Repetitive elongation is a very common form official procedure permitting to measure of deformation in textile materials and permanent deformation involved by a very high especially in knitted structures. Knitted fabrics number of cyclic elongations that simulates the are tendent to direct proportionnal employed in use of a knitted garment. Several works in the clothing undergo a very large number of past have examined the dimensional behaviour elongations when putting the apparel on or of knitted fabrics at rest or under constant
JOURNAL OF SCIENCE & TECHNOLOGY • No. 94 - 2013 forces. The key element is the geometry of the
I knitted loop have significantly contributed to the geometric analysis of plain knitted fabric.
But in most cases, the plain knitted fabric was described with very simple geometrical shapes such as arcs of circle and segments[l].
Alternatively the dimensional properiies of knitted fabrics were studied by some researchers using the force method. In the theoretical models of Postle et al. and Hepworth et al. yarn was treated as a perfectly elastic structure that is naturally straight. A theoretical work accomplished by MacRoy et al. attempted to describe load-extension phenomenon of plain knitted fabrics. MacRoy's Model emphasized slippage between loops and applied load with loop elements being straightened. This arcticle studied the dimensional behaviour of a plain knitted fabric made of cotton under constant load.
When stress is applied constantly, there is an increased extension with time in viscoelastic materials. This phenomenon is called creep [5], [6]. When the load is removed, there is immediate partial recovery of the deformation followed by a delayed recovery over a period. This recovery is known as creep recovery [5]. Almost all textile materials exhibit an appreciable amount of creep. An obvious example is the creep of garments due to their storage In the stores for a long time. If a garment is hung on a hanger for a long time. It will deform at fulcrums under its weight. Sometimes this deformation sets in the garment and is unrecoverable. This is the creep phenomenon, which is undesirable especially for luxurious garments. The material and stmcture of the textiles as well as the amount of load and environmental condition affect the creep behavior of textile materials. Creep behavior of fibers and yams is important In the yam and fabric making processes.
The aim of this study is to evaluate the creep phenomenon of knitted fabrics in depending on the change of loop length of the fabrics.
1.1. Creep and creep recovery
In a test of creep, load value start at zero and suddenly increases to a constant value (TQ ,
Changes in the deformation E whh time t is recorded and creep function is defined:
f(ffo,f)=^
After certain time T, load can be suddenly tum to zero. The creep and creep recovery curve is presented in Fig 1.
Fig. 1. Creep curve Ej. - relative deformation
Ep - constant deformation
hi this case, the curve consists of two parts, the first is called creep curve and the second Is recovery curve. A long time after removal of test specimens, the deformation to a constant value e^
can equal to zero and is called constant deformation.
2. MATERIALS AIVD METHOD 2.1 Materials
Three basic and commonly weft knitted fabrics in Vietnam are Single, Rib 1x1 and Interlock, which were used in this research.
Knitting process of experiment fabrics was conducted in Dong Xuan Knitting Company (DOXIMEX) - Ha Noi, on the Single circular knitting machine (Unitex, Singapore), Rib circular knitting machine (Fukahara, Japan) and Interlock circular knitting machine (Fukahara, Japan), respectively. All these knitting machines have the machine gauge of 21.
Tlie levels of fabric's loop length were changes based on the ability technology of knitting machines. Each fabric has 5 different loop length levels (Table I),
2.1 Experiment method
The samples were prepared according to ISO 13431 (01/8/1999). The samples were cut with size 300x50 mm in which the working length of fabric sample is 200 mm.
JOURNAL OF SCIENCE & TECHNOLOGY • No. 94 - 2013 Table 1 The eharaeteristies of investigated knitedfabrics
Single jersey LSD-352R LSD-362R LSD-372R LSD-382R LSD-392R R i b l x l 209-413R 209-428R 209-443 R 209-458R 209-473 R Interlock 409-343R 409-353R 409-363R 409-373R 409-383R
Loop length (i 00 stitch) 352 362 372 382 392 413 428 443 458 473 343 353 363 373 383
couses/100 mm 205 210 200 190 190 235 220 215 210 205 177 170 163 157 150
Wales/100 mm 145 138 131 128 127 198 195 193 190 185 145 141 139 134 127
Specific mass (E/m^l 137 135 134 132 130 145 142 139 133 129 185 182 187 177 170 One end of specimen is fixed to a clamp
and the lower end is suspended with a constant load, which is about 20% of strength and observed for 4 hours. The creep study of knitted fabric was carried out independently to find out the effect of various durations of loaduig on creep.
Recording the results of instantaneous deformation of die sample at the time of the load applied to the sample (at 20 first seconds). Then recording the results of specimen deformation at the point 5,10,30,60,90, 120,150,180,210and 240 minutes.
After 4 hours, load was removed, remouved the sample, after that immediately measure the length of the sample , the resuh is recorded.
That is the Immediate creep recovery, Sample was measured at the time: 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 12 hours, 24 hours and 48 hours. Record the results at the time.
3. RESULTS AND DISCUSSION Based on the experimental results, using Maple 16 software to interpolate the function relationship based on the least squares method.
From the interpolation equation drawn curves show the relationship of creep deformation and creep recover' with time.
Creep and creep recovery curves of all investigated knitted fabric by vertical direction and by horizotal direction are presented in Figures 3 to 5 and 6 to 8.
25 -J
V-
M Sl"-
^'
^ -
^••—
^ = IE
r~
E
10 1
=
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s s
D r .
g
m c
""
n .
"•"
10 4
==
u 101
-LCS-35IRIIP- - Lcs-aaa R I zp - • LCS.372 H13P - - I - C S - 3 K R 1 4 P -
Fig 3. Creep and creep recovery curves by vertical direction of single fabrics
102
JOURNAL OF SCIENCE & TECHNOLOGY * No. 94 - 2013
-- —
= ^
^ « . E m B
r~
.^~
Kf.r F A B
""^^^
R.C:
—
s a n ^
~^
V'
i i ; ; ;
/
''g i.e reepan ldc 'eef J re zov ^ry cun ves >y\ erh cai dir 'ction c f rib fabrics1 ^ =
I—o-4<»j«3K*»p *ta-axiwi —tm^nmmo JwawR Fig 5. Creep and creep recovery curves by vertical direction of interlock fabrics.
CREEP ADD CKEErRECOVERT CUBVERT OF S COD B ^ aHGI.E KNITTED FABRIC SAMPLES
I — 0 - L g » ; ^ 5 I B ' » r i L C ^ J ^ B I Z W L C S . 3 7 1 R I 3 H - ^ L C » J « 2 a f « — — i < » . » 2 K i a w ]
Fig 6. Creep and creep recovery curves by horizotal direction of single fabric.
Fig 7. Creep and creep recovery curves by horizotal direction of rib fabrics.
103
JOURNAL OF SCIENCE & TECHNOLOGY • No. 94 - 2013
Fig 8. Cl i.'ep and creep recovery curves by horizotal direction of interlock fabrics.
REFERENCES
1. Saber Benabdessalem, Saber Elmarzougui. "Dynamic Fatigue of Plain Knitted Fabric". Journal of Textile and Apparel, technology and management. Volume 5. Issue 2. 2006.
2. Virginijus Urbelis, Antanas Petrauskas, "Creep and Creep Recovery Behaviour of Textile Fabrics and their Fused Systems". Materials Science. Volome 11. pp 162-168. 2005.
3. V, Urbelis, A, Petrauskas and A. Vitkauskas. "Time -Dependent Mechanical Behaviour of Heterogeneous Textile Fabric Systems" Fibres & Textiles in Eastern Europe, Volume 12, No 4, 2004, pp, 37-42.
4. R.P. Nachane & G.F.S. Hussain. "Inverse creep in some textile yams", Indian Joumai of Fibre
& Textile Research, Volume 23, 1998, pp. 81-84.
5. Chu Dieu Huong, Nguyen Thi Hang. "Effect of loop length on the extension properties of knitted fabric". Journal of Science & Technology, 88-2012,
6. Chu Dieu Huong, Dao Thi Chinh Thuy " The dimensional stability of knitted fabric for perssure garment". Journal of Science & Technology, : i-2012.
Author'address: Chu Dieu Huong- Tel.: (+84)1698134359, Email: [email protected] School of Textile - Leather and Fashion.
Hanoi University of Science and Technology No. 1, Dai Co Viet Str., Ha noi, Viet nam