Indian Journal of Fibre &Textile Research Vol. 16, December 1991, pp. 257-262
Durability of modal and its blends:Part I
R Vatsala
Department of Textiles and Clothing, College of Home Science A P Agricultural University, Hyderabad 500016, India
and V Subramaniam
Textile Technology Department, A C College of Technology Anna University, Madras 600 025, India
Received 16 January 1991; revised received 16 September 1991; accepted 1 October 1991
An attempt has been made to assess the durability characteristics of modal textile and its blends with polyester and cotton by subjecting them to repeated laundering using a common detergent. It is found that they require gentle laundering and careful handling to retain their shape. An increase in modal (Md) content in modal/cotton (Md/C) blends results in a drop in the tensile strength of blended fabrics. This effect of Md is not so pronounced in modal/polyester (Md/PE) blends. Increased addition of modal to polyester or cotton decreases the tear strength of the blends in both dry and wet conditions, irrespective of their use in singles or ply yarns. In wet condition, the trend is maintained but there is a further loss in tear strength.
Keywords: Breaking strength, Dimensional stability, Tear strength 1 Introduction
Consumers can make wise selection if some information on the performance characteristics of fabrics is known to them. In this work, an attempt has been made to assess the durability characteristics, viz.
dimensional stability and strength, of modal (Md) textile and its blends wth polyester (PE) and cotton (C) by subjecting them to repeated laundering using a common detergent. Of all the performance characteristics, dimensional stability and strength are the most important factors which determine the durability of the fabrics directly. The influence of other factors such as appearance, texture, etc. will not be of any avail if a fabric has no sufficient strength and stability in size and shape. Therefore, in the present work, performance of blended modal/polyester (Md/PE) and modal/cotton (Md/C) has been studied in terms of dimensional stability and strength.
The fit of a garment determines, to a large extent, the serviceability of a fabric. Hence, the dimensional stability of a fabric meant for clothing is relevant to a consumer. Dimensional changes in a fabric can manifest themselves in shrinkage in two directions, growth in one direction, growth in two directions and growth in one direction and shrinkage in the other".
In day-to-day use of textiles, tear resistance is
important for consumers' satisfaction. Fabrics with greater tear resistance tend to be more durable.
Therefore, tear strength of fabrics is an indication of durability.
2 Materials and Methods
Six MdjPE blends (3 shirtings A-C and 3 suitings D-F) and four Md/C blends (2 shirtings G&Hand 2 suitings I&J)having varying modal content, a 100%
modal sarce (K) and a 100% modal suiting (L) were subjected to nil, 10, 20 and 30 machine launderings using an anionic detergent. Fourteen Md/C blends (7 shirtings M-S and 7 suitings T-Z) were specially woven and tested. The construction particulars are given in Table 1.
2.1 Washing
The washing machine used was the impeller type with unidirectional rotation that is generally used by the Indian consumers. It's capacity was 3 kg and it had a timer. The AA TCC method formed a part of washing procedure". Tap water (hardness, 112 ppm;
pH, 7.4 using a 0.2% detergent solution) was used at 41
+ /-
3°C for laundering. The washing was done for 15 min followed by 3 rinses of3 min each with water.The fabrics were then spin dried for 10 min and
Table I-Construction particulars of test fabrics (plain weave)
Fabric composition Weight Thickness Ends/em Picks/em
g/m2 mm
Modal : Polyester
A (35:65) 77 0.167 38 36
B (52:48) 107 0.178 39 37
C (65:35) 125 0.188 42 37
D (52:48) 111 0.187 41 32
E (33:67) 178 0.337 32 24
F (67:33) 174 0.277 29 24
Modal : Cotton
G (52:48) 108 0.203 36 28
H (65:35) 128 0.216 56 60
1(16:84) 171 0.323 32 24
J (84:16) 179 0.295 31 24
Modal
K (100%) 168 0.234 32 24
L (100%) 64 0.163 30 26
Modal : Cotton (ShirtiDg)
M (0:100) 155 0.122 32 28
N (16:84) 144 0.117 32 28
0(33:67) \36 0.114 32 28
P (50:50) 134 0.117 32 28
Q (67:33) 132 0.109 32 28
R (84:16) \30 0.107 32 28
S (100:00) 129 0.096 32 28
Modal : Cotton (SWing)
T (0:100) 163 0.177 25 25
U (16:84) 172 0.182 25 24
V (33:67) 166 0.170 25 25
W (50:50) 175 0.175 25 25
X (67:33) 172 0.175 25 25
Y (84:16) 171 0.177 26 24
Z (100:00) 160 0.167 26 25
pressed. The fabrics A to L were subjected to nil, 10, 20 and 30 machine launderings (UL, 10L, 20L and 30L respectively) using a common anionic detergent composed of 21.373% phosphates, 36.12% active matter and having a pH 9.8. The fabrics M to Z could not be tested for their properties when conditioned and wet due to the paucity of these samples.
2.2 Tests
Unlaundered and laundered fabrics were tested for dimensional stability as per the AATCC method", The breaking strength was tested as per ASTM D
1982-64 (reapproved 1975) using CRT Machine. The
experiments were carried out in both wet and dry conditions. Samples M-S were tested for their tear resistance as per the Indian standard specifications".
Elmendorf tear tester was used for the purpose.
3 Results and Discussion
3.1 Dimensional Stability
Table 2 shows that most of the test fabrics have poor dimensional stability. The per cent change in dimensional stability beyond the stipulated pre-shrunk quality limits of
+ / -
1% for all fabrics except E and K at increasing levelsoflaunderings showsVATSALA & SUBRAMANIAM: DURABILITY OF MODAL AND ITS BLENDS
Table 2-Effect of laundering on dimensional stability of test fabrics
Fabric %change in dimensional stability
Warp Weft
IOL· 20L 30L 10L 20L 30L
Modai/PoIyester
A 1.72 2.00 2.56" OAO OAO 0.12
B 2.12 2.28" 3.20' 0.68 0.92 1.48
C 2.12 2.40' 3.75 1.08 1.88 2.04"
D 0.92 1.08 1.46 0.40 0.52 0.68
E 0.68 0.12 0.68 0.84 +0.22 +0.40
F 1.00 1.72 3.28c 0.80 0.28 1.48
Modal/Cotton
G 2.00 2.40" 4.00 + 15.48b 5.82a 4.40"
H 6.28b 0.52 0.40 +20.32b +2.40 +2.40
I
J 4.& 3.40" 5.88a 7.20b +9.20b +8.63b
Modal
K 3.20" 3.20" 3.88a 3.60b 3.72a +1.72
L 3.& 4.40" 5.72" 0.68 +1.60 +0.28
'Shrinkage beyond the 'sanforized' standards.
~Stretch beyond the 'sanforized' standards.
"Shrinkage beyond specifications for suitings.
Values with + sign indicate increase in dimension (stretch in %)and the other values indicate shrinkage %.
that the change could be due to: (i) the innate high water absorption capacity ofMd, (ii) swelling ofMd in water accelerated by detergents as the detergents increase the movement of the water molecules i.e.
pedesis and penetrability of water into the fabric like a wetting agent, (iii) thickness or bulk of the fabric in case of suitings, (iv) agitation resulting in mechanical pull, and (v) temperature of washing.
If these fabrics are to maintain good dimensional stability, special care should be taken when laundering them in view of the above attributes.
Fabric stretch is more than the standards of sanforization. In general, MdjC suitings show a tendency to sag more than shirtings, sarees and MdjPE suitings. This may be because of greater absorbency ofMd which renders the fabric heavy and causes sagging when hung to dry. The suitings need careful handling to minimize dimensional instabili ty.
3.2 Breaking Strength
Table 3 and Fig. I show that there is an overall fall in the breaking strength of samples with multiple launderings in the case of MdjC blends. This is in
agreement with the observation of Lord" in a more or less similar study with MdjC blends. Among the Md/PE suitings, sample E shows the highest breaking strength in both unlaundered and laundered states as has also been observed by Maurer and Martin".
However, MdjPE suitings show a lesser fall in strength compared to MdjPE shirtings in general.
This could be due to the use of two-fold yarns in the former, as observed by Ravindranathan and Balasubramanian '. Accordingly, the increase in strength of two-fold yam is due to the lateral pressure of its constitutent singles and also due to the pressure produced by the interlacement of two-fold yarns in the fabric; these two pressures are capable of compensating for any inherent weakness in the yarn and fabric.
All MdjC suitings show a higher strength both in unlaundered and laundered conditions compared to shirtings. MdjC blends, like MdjPE, show a fall in their strength (Fig. I)which is corroborated by the findings of Filatov et al.8.The 25% strength loss in sample L as compared to K can be attributed to the use of two-fold yams in latter in addition to being thicker and heavier.
The breaking strengths of conditioned and wet samples M-S are given in Table 4. The sample R, which is a 84: 16 Md/C blend, shows the maximum breaking strength while sample M (a 100% modal fabric) shows the least both in conditioned and wet states. All fabrics, excepting R, show a fall in their breaking strength when wet. An increase in the modal content in the Md/C blends results in a fall in the breaking strength in general.
3.3 Tear Strength
A large drop in the tear strength of all Md/C blends
Table 3-Effect of laundering on breaking strength of test fabrics
Fabric Breaking strength, N
UL IOL 20L 30L
Modal/Polyester
A 132.44 117.82" 100.26a 108.40·
(- 11.00) (- 24.30) (-18.15) B 218.74 rss.ro- 183.25a 183.06"
( -14.93) (- 1623) ( -16.32)
C 220.43 181.68 160.88a 163.63"
(-17.58) (-27.01) (- 25.77)
D 193.55 172.17
(- 11.05)
E 333.93 332.07
(- 0.56) Modal/Cotton
G 130.57 112.91 124.49 118.51
(- 13.52) ( -4.66) (- 9.24)
H 219.16 180.01 164.42
(-17.84) (24.98) (- 26.99) 255.55
J 194.24 144.31
(-25.71) Modal
K 162.94 124.10
(~ 23.83)
L 85.35 64.75a
(-24.14)
52.39a
(- 38.62)
41.59a
(-51.27) 'Significant at 0.01% level.
Values in parentheses indicate per cent change.
is observed after multiple launderings (Table 5).This drop in the Md/C blends after multiple laundering is in agreement with the findings of Ruppnicker".
Though Md/pE blends also show a drop, it is not up to
80
70~~ ~ L- ~--J
UL mL WL
Ll'vl'1 of laundering
Fig. l-s-Effect of laundering on breaking strength 220
200
Z 180
L0.
c 160 iii~ .!::01 140
.><
o
••
•...
In 120
100
-<>-M:PE(52148) --- M:C (65135 ) -Ir M:C (52148) -*-·M:PE(65/35 )
~M:PE(35/65) -- M ( 100'1.)
Fabric
Table 4-Breaking strength of conditioned and wet shirtings Breaking strength [(warp +weft)!2], N Conditioned
Modal/Cotton
M 380.63
(100.00)
N 388.48
(102.16)
0 339.43
(89.18)
P 324.71
(85.31)
Q 290.38
(76.29)
R 258.00
(67.78)
S 241.33
(63.30)
Wet % Difference
374.74 -1.55
(100.00)
401.23 +3.18
(107.01)
326.67 -3.76
(87.15)
272.72 -16.01
(72.78)
207.87 - 28.41
(55.43)
141.46 -45.17
(37.75)
132.73 -45.00
(35.42)
Values in parentheses indicate the per cent change relative to 100%cotton and are significantat 0.0 I%level except in the caseof samples 0and R in wet condition.
VATSALA & SUBRAMANIAM: DURABILITY OF MODAL AND ITS BLENDS
Table 5-Effect of laundering on tear strength Table 6-- Tear strength of conditioned and wet shirtings of test fabrics
Fabric Tear strength, N Fabric Tear strength [(warp+weft)/2]
UL IOL 20L 30L Conditioned Wet
Modal/Polyester N kg N kg
A 186.90 145.09 133.81 142.82 Modal/Cotton
B 175.21 121.55 102.02 97.12 M 13.03 1.33 13.03 1.33
(HlO.OO) (100.00)
C 173.54 114.30 90.45 80.50
N 12.09 1.23 5.96 0.61
D 140.33 96.92 (92.64) (-)
E 165.90 169.61 0 9.55" 0.97 6.44" 0.66
(73.18) (49.42)
F 177.76 133.51
p 9.40" 0.96 6.75" 0.69
Modal/Cotton (72.03) (51.80)
G 135.30 70.40 73.08 62.10 Q 9.57" 0.98 8.79 0.90
(73.33) (67.41)
H 170.40 83.09 76.91 67.49
R 9.89 1.01 9.73 0.99
155.19 (75.90) (74.67)
J 137.34 S 12.09 1.23 11.77 1.20
(92.79) (90.30)
Modal
K 134.20 89.76 "Significant at 0.05% level.
Values in parantheses are relative to 100% cotton.
L 171.00 67.59 71.81 58.76
the magnitude ofMd/C and 100% Md (Table 6). This is attributable to the PE component in MdjPE blends.
In the case of Md/C blends, tear strength is observed (Fig. 2) as has also been reported by Bansal et al.:".
Thus, there is a highly significant reduction in the tear strength ofMdjC blends. Insignificant advantage in the use of two-fold yarns over singles was observed in the present work as has also been noticed by O'Brien II.The onlysample which shows an increase in tear strength also happens to be the one which took several hours to get wet in the 'drop dispersion' test, referred to elsewhere, which indicates the presence of lubricating and other finishing agents on the fabric which make it impervious to water. Probably, the same water-repellent finish explains the yarn mobilityl2.13 and the increased yarn strength of this sample even after multiple launderings.
3.4 Effect of Moisture on Tear Strength
The wetting of Md/C results in decrease in tear strength which can be due to the modal component.
13 z, 12
.C-
ooc
~ 11 on
~ io
J
" 'Z!----o:..L\O-O-'6....L':-S4-3t67·51).50 67~33 e4~16 1O(rO
Blend c omposIfio n (M:C)
Fig.2-Effect of blend composition on tear strength
Patel et al,":reported a loss of 30-43% in the case of 65:35 Md/C whle Ananthan!' reported a loss of56%
for a similar blend. The wide range in loss of tear strength in the present work could be due to the wider range of Md/C blends studied. The highest strength registered by sample R compared to the others indicates that the addition of more Md reduces the
tear strength while the reverse is the case with the addition of cotton.
4 Conclusions
The heavier blends of modal with polyester and cotton have low dimensional stability and so will not be suitable for suitings for which the expected drape is different from that of other items such as dress materials.
An increase in the modal content of the fabric results in a decrease in its breaking strength.
Therefore, blending modal up to 16% with cotton for shirtings is desirable in view of its durability. Pure modal fabrics have low breaking strength followed by modal/polyester and modal/cotton blends. In general, all polynosic and polynosic blended textiles need gentle handling while laundering. This is specially so with modal/cotton blends as they tend to elongate more, specially when wet. Modal/polyester shirtings with higher modal content retain their strength better than modal/cotton blends.
Addition of modal to cotton or polyester reduces
their tear strength which is further lowered on wetting the blends.
References
I Balachandran Iyer S,Man-Made Text India. 18 (1975) 568.
2 AATCC, 143 - 1975.
3 AATCC, 139 - 1978.
4 Indian stan!ard specifications IS:6489 (Indian Standards Institution, New Delhi), 1971 (reaffirmed 1987).
5 Lord J, Text Inst Ind. 13 (1975) 188.
6 Maurer N Martin, Textilveredlung, 52 (1976) Translated.
7 Ravindranathan V&Balasubramanian N, Text Res J, 48 (1978) 389.
8 Filatov, Text Prog, 27 (1967) 63.
9 Ruppnicker G F, Am Dyest Rep. 60 (1971) 3\.
10 Bansal A P, Shah R K. Garde A R & Shah R K, ATIRA circular report. MP CT/97, March 1978.
II O'Brien W E&Weiner L I, Text Res J,24 (1954) 241.
12 Truslow N, Am Dyest Rep, 43 (1954) 4\'
13 Clark AJ, Polym surfaces (John Wiley and Sons, New York) 1978,235.
14 Patel A B,Dave B S&Patel I M, Colourage, 27 (1980) 3.
15 Ananthan T V& Radhakrishnan M, Some aspects of the physical properties of blended fabrics, paper presented at the 34th All India Textile Conference, Coimbatore, December 1977.
