Investigating the Effect of Elastane Use on Tailorability and Appearance of Wool and Wool Blend Suiting Fabrics

ABSTRACT

In this study, the effect of the use of elastane on the tailorability and appearance of 100% wool and different proportions of wool – man-made fiber blended worsted suiting fabrics was investigated. The evaluations were made by means of mechanical properties. Although the amount of elastane used in the weft yarn of elastane-containing fabrics differed in each group, it was observed that the effect of elastane varied mainly depending on the fabric weight. It was seen that the use of elastane increased the bending rigidity for heavy weight (290 g/m² and above) fabric groups (groups 1 and 6) and negatively affected tailorability due to low shear rigidity for fabrics other than these groups. Except for the group with low fabric weight, all groups were found to improve the appearance in both weft and warp directions. However, it was concluded that fabrics containing 7% or more elastane in the weft may have a seam puckering problem due to low formability in the warp direction. The effect of elastane on extensibility was found to be influenced by fabric density, elastane content and construction in addition to fabric weight. The low fabric density and weight caused excessive extensibility, resulting in very poor tailorability.

摘要

研究了弹性纤维的使用对100%羊毛和不同比例羊毛-人造纤维混纺精纺西装面料的可裁剪性和外观的影响. 通过机械性能进行评估. 尽管含弹性纤维织物的纬纱中使用的弹性纤维的量在每组中不同，但观察到弹性纤维的效果主要取决于织物的重量. 可以看出，弹性纤维的使用增加了重重量（290 g/m² 及以上）织物组（第1组和第6组）的弯曲刚度，并且由于这些组以外的织物的低剪切刚度而对可裁剪性产生了负面影响. 除了织物重量较低的组外，所有组都能改善纬纱和经纱的外观. 然而，得出的结论是，纬纱中含有7%或更多弹性纤维的织物可能由于在经纱方向上的低成形性而具有接缝褶皱问题. 弹性纤维对延展性的影响受织物密度、弹性纤维含量和结构以及织物重量的影响. 织物密度和重量低导致延展性过大，导致可裁剪性非常差.

KEYWORDS:

• Tailorability
• elastane
• appearance
• suiting fabrics
• woolen fabrics
• mechanical properties

关键词:

• 可定制性
• 弹性纤维
• 外貌
• 西装面料
• 羊毛织物
• 机械性能

Introduction

Wool and wool blended fabrics are indispensable for suits. Since these garments are expensive, the expectation of quality from them is quite high. The consumer’s expectations from a quality garment are fabric quality, good appearance, comfort and wearability. Garment manufacturers, on the other hand, expect the fabric to be easy to tailor, to pass through the make-up (garment production) process easily and without unnecessary problems (Behera 2015; Fan and Hunter 2009). The use of elastane in outerwear fabric blends is preferred to improve flexibility for good appearance and wearability, and comfort (Ozdil 2008; Senthilkumar 2011).

One of the most common methods of producing elastic fabrics is by using core-spun yarns. Nowadays, the sirospun method is also used to produce wool and wool blended yarns containing elastane. Sirospun yarns are favored in the worsted industry due to their better wearability (Elkhamy 2007).

In many studies on improving the quality of wool and wool blend fabrics, it has been stated that good quality fabrics should have high extensibility and low shear rigidity, that wool and wool-rich fabrics are generally more easily adapted to good-looking garments than polyester-rich fabrics due to their higher extensibility and formability levels, and that low weight fabrics with low bending stiffness, low shear rigidity and low formability will cause tailoring problems during laying, cutting, sewing and fabric manipulation (Fujiwara 1983; Postle 1986; Wang, Postle, and Zhang 2003). De Boos and Roczniok (1996) attempted to modify the formability of fabric through the finishing process by increasing the extensibility of the fabric. Tokmak (2008) investigated the mechanical and performance properties of wool and wool blended fabrics with objective evaluation systems and searched for a reliable relationship between the physical and mechanical properties of these fabrics

Geršac (2004) investigated the relationship between fabric elastic potential, as an important property under lower tensile load, and garment appearance quality. Lam and Postle (2006) suggested in their study that the use of lycra in weft yarn has a significant effect on fabric mechanical properties and surface properties and that these are the most important properties explaining stiffness and tailoring properties. Varghese and Thilagavathi (2014) searched the elongation, bending, shear, surface, and compression properties of the stretch fabrics made from different fibers using KES-F. The study revealed that the stretch fabrics woven with polyester warp, cotton core spun lycra and polyester lycra in the weft had excellent aesthetic and drape properties. Jankoska and Demboski (2017) compared the mechanical properties, handle and tailorability of wool-blended fabrics for outerwear. The plain weave and twill weave fabrics with the same fiber composition and the same warp and weft count were tested in KES – F. Kim (2020) investigated the effect of the blend ratio of wool and polyester fibers, yarn and fabric structural parameters on the appearance properties and formability of worsted fabrics.

Tailorability was defined by Bassett as “the ease with which the fabric can be transformed into the intended end product” (Wang, Postle, and Zhang 2003). In the tailoring process, the fabric is stretched many times and the mechanical properties of the fabric change significantly under these moderate stresses. The elastic potential of the fabric has a direct influence on its mechanical properties (Pavlinic´ and Geršak 2003; Geršak 2003). The low-stress mechanical properties of fabrics are critical in determining both the quality and performance of fabrics and garments and the tailorability of the fabric (Behera 2015). Appearance is an important quality characteristic that both the manufacturer and the consumer expect from a well-made suit (Wang, Postle, and Zhang 2003). This characteristic is closely related to fabric formability (Geršak 2003), which depends on the initial modulus, extensibility and bending stiffness of the fabrics (Behara and Mishra 2007). It is obvious that elastane has a great influence on the extensibility, softness and therefore the bending rigidity of the fabric, which in turn will affect the tailorability and appearance of the garment. Therefore, investigating the effect of the use of elastane on the mechanical and physical properties of wool and wool blended suit fabrics is an important issue to ensure the high quality requirements expected from these fabrics and to take precautions against problems that may occur during garment production. When the literature was examined, it was seen that there are very limited studies on the effects of elastane use in woolen fabrics on appearance and no studies on the effect on tailorability. It is believed that this study will help to fill the gap in this field.

In this study, the effect of elastane use for 100% wool and wool/man-made fiber blends at different ratios on the tailorability and appearance of worsted woven fabrics was investigated. For this purpose, the most preferred wool, wool/polyester, wool/nylon and wool/polyester/nylon blended fabrics were selected with and without elastane. In the study, ready-made commercial fabrics produced for suits by an integrated worsted woolen-weaving mill with a high market share were used. The fabrics were grouped and the mechanical properties of the fabrics with and without elastane in each group were compared. The effect of the use of elastane on tailorability and appearance was evaluated through mechanical properties. These properties were measured by SiroFAST instrument.

Materials and methods

Materials

In this study, 100% wool and different ratios of wool/polyester, wool/nylon, and wool/polyester/nylon fiber blended woven fabrics and fabrics obtained by adding elastane at certain ratios were used. Elastane was used in weft yarn. In all, 12 types of fabrics were divided into 6 groups so that the fabrics with and without elastane in each group had the same fiber composition. The fabrics in each group have the same fabric construction and approximately the same fabric and yarn properties (Table 1).

Table 1. Properties of fabrics.

Groups	Fabric Type	Fabric Composition*	Weft Density (Picks/cm)	Warp Density (Ends/cm)	Areal density (g/m^2)	Construction
1	W1	100% Wool	27	29	330	2/2 Twill
	W2	98% W/2% EA	27,5	28	330	2/2 Twill
2	W3	71%W/29% PES	23	28	230	Plain
	W4	72%W/26%PES/2% EA	23	30	240	Plain
3	W5	50%W/50% PES	29	37	270	2/2 Twill
	W6	47%W/51% PES/2% EA	27	35	280	2/2 Twill
4	W7	24%W/76% PES	28	33	250	2/2 Twill
	W8	22%W/76% PES/2% EA	25	30	270	2/2 Twill
5	W9	74%W/18% PES/8%NY	37	39	245	3/1 Twill
	W10	65%W/24% PES/8% NY/3% EA	35	38	250	3/1 Twill
6	W11	90%W/10%NY	31	38	290	2/1 Twill
	W12	88%W/10%NY/2% EA	32	36	290	2/1 Twill

*W- Wool; EA-Elastane; PES-Polyester; NY-Nylon.

The yarns of the fabrics were spun by sirospun spinning method in the same integrated factory. All fibers are staple except elastane. The elastane used in fabrics is Dupont brand Lycra. Only the fabrics of group 5 additionally contains continuous PES yarns in the weft and warp direction. Yarn properties were shown in Table 2.

Table 2. Specifications of fabric yarns.

Fabric Groups	Fabric Code	Warp count (Nm)	Twist Direction	Warp Yarn Composition	(T/m)	Weft count (Nm)	Weft Yarn Composition	Twist Direction	(T/m)
1	W1	52/2	S	100% Wool	550	64/2	100% Wool	Z	660
	W2	52/2	S	100% Wool	550	60/2	96%W-4%EA	Z	667
2	W3	80/2	S	70%W-30% PES	750	70/2	70%W-30% PES	Z	750
	W4	80/2	S	70%W-30% PES	750	72/2	72%W-26% PES-2% EA	Z	750
3	W5	76/2	S	50%W-50% PES	667	76/2	50%W-50% PES	Z	750
	W6	76/2	S	50%W-50% PES	667	80/2	43%W-53%PES-4% EA	Z	750
4	W7	80/2	S	45%W-55% PES	667	90/2	45%W-55% PES	Z	667
		45/1		100% PES *		45/1*	100% PES *
	W8	80/2	S	43%W-56% PES	750	90/2	43%W-53% PES-4% EA	Z	750
		45/1		100% PES *		45/1*	100% PES *
5	W9	90/2	S	85%W-15% NY	800	90/2	60%W-40% PES	Z	750
	W10	90/2	S	85%W-15% NY	800	88/2	42%W-51%PES-7% EA	Z	750
6	W11	88/2	S	90%W-10% NY	750	90/2	90%W-10% NY	Z	750
	W12	88/2	S	90%W-10% NY	750	88/2	83%W-13%NY-4% EA	Z	750

*Continuous (Untwisted) Yarn.

All fabrics were subjected to open width continuous washing, drying, singeing, and decatizing processes in the finishing conditions of the integrated mill. Only the fabrics in Group 1 were subjected to a light milling finish. Drying conditions for all fabrics are 110°C, 45 seconds-1 minute. Decatizing conditions are 100–110 degrees, 1 bar steam and 150 seconds for wool/PES blended fabrics (Group 2, 3, 4 and 5). For wool and wool/nylon blended fabrics (group 1 and 6), only the time is different and is 180 seconds.

In this study, the wool fibers used in all yarns are Australian merino wool fibers. Average length of wool fibers is 72 mm. The fineness of the wool fibers was the same in each group, but there were differences between the groups. Fiber finenesses used in the groups are 21–25 microns for groups 1,2,3,4 and 5, 21 microns for group 6 and 25 microns for group 7. The fineness of the staple nylon and pes fibers is 2 and 2.4 DNY and the length is 88 mm, respectively. The yarn count of continous PES filament is 200 DNY. In addition, the fineness of the elastane fiber (Lycra®) used in the weft yarn in fabrics is 36 DNY.

Methods

In this study, the physical and mechanical properties of the fabrics were tested by means of SiroFAST measuring system. After fabric samples were conditioned under standard laboratory conditions (20 ± 2°C, 65 ± 2% relative humidity). The sample size was 150 mm x 50 mm for SiroFAST-1, SiroFAST-2 and SiroFAST 3 tests. SiroFAST-1 compression tests were performed with five replicates. SiroFAST-2 Bending meter tests and SiroFAST-3 Extension tests were done 3 warp 3 weft replicates (De Boss and Tester 1994).

SiroFAST (Fabric Assurance by Simple Tests) is the latest integrated set of instruments and test methods for the objective measurement of fabric developed by the CSIRO Wool Technology Division in Australia. SiroFAST system is used to predict the performance of fabric in garment production and the appearance of garments during wearing by measuring the mechanical and dimensional properties of the fabric. SiroFAST consists of three instruments and a test method: SiroFAST-1 is a compression meter that measures fabric thickness, SiroFAST-2 is a bending meter that measures the fabric bending length, SiroFAST-3 is an extension meter that measures fabric extension under different loads, SiroFAST-4 is a test procedure for measuring dimensional properties of fabric. The results obtained from the SiroFAST system are transferred to FAST control chart called “fabric fingerprints.” The gray areas and limits on the chart serve as a warning of a potential problem in production and end use, and provide detailed information about the tailorabilility of fabric (De Boss and Tester 1994). The lower and upper limits of the tested properties are given in Table 3. The evaluations were made according to the zone where the results fall on the chart. All the test results were analyzed statistically with SPSS. Levene’s test was performed to control for variances and“t-test for independent samples” was performed to determine the significance of the differences (in case of p < .05) between the mechanical properties of fabrics in the same group (Table 4). In the Table 4, “Sig. (2-tailed)” values show the statistical significance (p value).

Results and discussion

The results of the mechanical and physical properties of the fabrics tested with SiroFAST were shown in Table 3.

Table 3. SiroFAST results of fabrics.

		1.Group		2.Group		3.Group		4.Group		5.Group		6.Group
Performed Test	Optimum Range	W1	W2	W3	W4	W5	W6	W7	W8	W9	W10	W11	W12
E100–1*(%)	%2< >%6	2,30	2,87	3,27	3,07	1,57	2,93	1,43	5,13	1,53	2,23	1,80	3,27
E100–2(*%)	%2< >%4	7,90	8,10	2,93	14,20	2,93	7,57	2,37	6,50	3,27	6,77	3,77	5,73
B1*(µN.m)	15< >5	11,31	17,06	7,17	5,84	7,00	7,50	5,80	7,00	6,60	5,90	7,67	15,25
B2*(µN.m)	15<>5	6,04	11,74	8,37	3,99	5,60	3,70	4,50	5,00	3,50	2,60	5,00	13,83
F1*(mm^2)	>0,25	0,23	0,62	0,45	0,16	0,13	0,29	0,09	0,51	0,18	0,23	0,10	0,86
F2*(mm^2)	>0,25	0,82	1,52	0,18	1,45	0,25	0,45	0,15	0,44	0,21	0,43	0,20	1,19
G(N/m)	30< >80	17,43	16,30	19,17	14,27	27,00	12,70	19,00	13,30	24,30	13,30	16,63	19,80
T2(mm)	.2< >1.4	0,83	0,76	0,22	0,32	0,32	0,36	0,26	0,33	0,21	0,45	0,26	0,35

*1-warp direction 2-weft direction.

Table 4. Statistical analysis results.

		Levene’s Test for Equality of Variances	t-test for Equality of Means
				95% Confidence Interval of the Difference
Fabric Grups	Performed Test	Sig.	Sig. (2-tailed)	Lower	Upper
1	B-1	,729	,001	-7,668886	-3,824448
1	B-2	,087	,009	-9,078742	-2,314591
1	E100-1	,036	,368	-2,640046	1,506713
1	E100-2	,262	,143	-,403985	1,937319
1	F-1	,074	,185	-1,047878	,281212
1	F-2	,162	,023	-1,239160	-,154173
1	G	,078	,564	-3,877960	6,144627
2	B-1	,094	,004	,690369	1,962965
2	B-2	,503	,000	5,332807	6,467193
2	E100-1	,430	,051	,067320	1,599347
2	E100-2	,871	,000	-11,953022	-10,580311
2	F-1	,025	,013	,144095	,442571
2	F-2	,206	,019	-,426363	-,066971
2	G	,059	,005	2,476015	7,323985
3	B-1	,740	,038	,047645	,989481
3	B-2	,231	,001	-2,344759	-1,238229
3	E100-1	,259	,000	1,032979	1,700354
3	E100-2	,789	,000	4,263259	5,070075
3	F-1	,599	,004	,078594	,217503
3	F-2	,610	,005	,120505	,347892
3	G	1,000	,000	-14,753392	-13,846608
4	B-1	,602	,013	,348119	1,616882
4	B-2	,780	,132	-,187701	,989269
4	E100-1	,609	,000	3,421807	3,911526
4	E100-2	,561	,000	3,663141	4,403526
4	F-1	,108	,000	,302185	,495422
4	F-2	,530	,002	,167327	,392413
4	G	1,000	,000	-6,153392	-5,246608
5	B-1	,531	,289	-1,528554	,595220
5	B-2	,040	,013	-9,307244	-1,972756
5	E100-1	,065	,002	-2,016961	-1,249706
5	E100-2	,020	,000	-15,275634	-9,791033
5	F-1	,653	,001	-,140695	-,079305
5	F-2	,021	,036	-3,934792	-,338541
5	G	,783	,000	3,700439	6,099561
6	B-1	,169	,000	-8,807244	-6,346089
6	B-2	,105	,000	-10,946605	-6,733395
6	E100-1	,016	,001	-1,559215	-1,374118
6	E100-2	,034	,016	-1,610088	-1,323245
6	F-1	,103	,000	-,857065	-,662935
6	F-2	,283	,000	-1,077714	-,888952
6	G	,063	,025	-5,687649	-,645684

Thickness results

When the T2 fabric thickness values of the fabrics with and without elastane in the same group were compared, it was observed that the use of elastane caused an increase in thickness values in all groups except the first group (Figure 1). Elastane filament added to the weft yarn increased the fabric thickness (AL-Ansary 2011). The fabrics in the first group were subjected to a light milling process unlike the others. The milling finishing process has a large effect on the compressibility of the fabric (De Boss and Tester 1994). The lack of thickness increase in this group was related to this process. The thickness difference was omitted in this study.

Figure 1. Thickness results of fabrics.

Extensibility results

In the SiroFAST chart, the upper limit for extensibility is 6% and the lower limit is 2%. The result between these two limits means that the measured property is in the problem-free zone. High extensibility causes unwanted fabric distortion during the cutting and sewing processes. If the extensibility is less than 2%, overfeeding and seam puckering problems occur during moulding (De Boss and Tester 1994; Kawabata, Ito, and Niwa 1992). The extensibility properties were measured under 100 gf/cm load.

The fabrics in groups 2, 3 and 4 contain different proportions of wool/PES blend and 2% elastane. Analysis for group 2 showed that the addition of elastane did not make a significant difference (p1=.051) in warp direction, while increasing the value to 14% in the weft direction, resulting in excessive extensibility due to the use of elastane in weft direction. For Group 3 and 4, it was observed that the addition of elastane significantly increased the extensibility (Figure 2) in weft and warp directions (Table 4). For both groups, the use of elastane solved the possible problems in sewing operations with overfeed in the warp direction. However, it caused the weft direction extensibility values to fall into the “matching problem” zone in the FAST chart.

Figure 2. Extensibility results of the fabrics.

In groups 5 and 6, nylon fibers were used unlike the others. The addition of elastane significantly increased the weft direction values for both groups (Table 4). These values were found be very close to the acceptance limits. In the warp direction, it increased the values and moved them to the problem-free zone, thus solving the problems caused by low extensibility (Figure 2).

When the results of the wool/PES blended fabrics in this study were examined, it was seen that the use of elastane maximized the weft direction extensibility for wool-rich group 2. This result is similar to the results of many studies (Kim 2020; Postle 1986; Wang, Postle, and Zhang 2003) for wool/PES blended fabrics. However, when the results of all groups were analyzed, it was seen that it was not correct to relate the elastane effect with the wool ratio. It is known that the specification of the fabric is an important factor affecting the mechanical properties of the fabric under low stresses. Among all groups, the weft density of the fabrics in-group 2 has the lowest value (23 picks/cm). Due to the lower weft density, the weft yarn containing elastane in Group 2 was able to extend freely and showed a very high extensibility value (Cataloglu 2007; Şekerden and Çelik 2010). In addition, this group has the lowest fabric weight among all groups (Table 1). It was considered that the high effect of elastane on weft direction extensibility was also influenced by the low fabric weight.

The use of elastane caused a significant increase in the warp direction in groups 3 and 4, while group 2 had no significant effect on the warp direction. The amount of elastane used in the second group (2%) is lower than in the other two groups (Table 2). In addition, the second group is a plain weave and the other two groups are 2/2 twill weave. Twill provides more extensibility (Behera and Shakyawar 2000). Due to the high number of intersections in the plain weave, the amount of elastane in the second group did not increase the extensibility in the warp direction. Therefore, the matching problem in the warp direction of the elastane-free fabric in this group could not be solved.

In this the first group, the addition of elastane increased the extensibility values in the weft and warp directions, but this increase was not statistically significant (Table 4). Unlike the other groups, the fabrics in this group were subjected to a light milling process. The milling process prevented high extensibility (De Boss and Tester 1994). In addition, this group has the highest weight of all groups (330 g/m²). Elastane did not produce a significant increase in extensibility in the heavy weight fabric. In this group, the extensibility values of the fabrics with and without elastane were in the problem-free region in the siroFAST chart.

High extensibility improves fabric quality, wearing comfort and appearance, but causes undesirable fabric distortion during cutting and sewing (De Boss and Tester 1994; Kawabata, Ito, and Niwa 1992). Therefore, fabrics in-group 2 should be treated with the necessary finishing processes to control their extensibility properties (De Boss and Tester 1994) or the fabric specifications should be redesigned.

Bending rigidity results

The bending length is a characteristic property of a woven fabric and is dependent upon the energy required to produce a given bending deformation under its own weight. This energy (Moment of Hysteresis) is closely related to bending rigidity. Fabrics with a large value of hysteresis moment are inelastic and have low elastic recovery, and feel stiff (Geršac 2004).The stiff fabrics have high bending rigidity values but relatively high values usually do not cause a problem in tailoring and are desirable for woolen fabrics as they improve appearance. In addition, too low values lead to some significant problems such as distortion during cutting, seam puckering, poor shape retention (Basu 2004). In the SiroFAST table, the lower limit is 5µ.Nm and the upper limit is 15µ.Nm (De Boss and Tester 1994). The bending rigidity results of all fabrics in the groups are shown in Figure 3.

Figure 3. Bending rigidity results of the fabrics.

When the results of the first group were analyzed, it was found that the use of elastane significantly increased the bending rigidity (Table 4) both in weft and warp directions (Figure 3). It caused a slight stiffness in the warp direction (17.06 µ.Nm) but improved the appearance.

The use of elastane significantly reduced the bending rigidity in both weft and warp directions in the group 2. In Group 3, the bending rigidity decreased in the weft direction but increased in the warp direction. The difference was significant only in the weft direction (p2 = .013). On the other hand, in group 4, elastane caused an increase in weft and warp direction values (Figure 3), but the increase was significant only in the warp direction (p1= .013). When the fabric properties of the 4th group were examined, it was seen that the weight increase in the fabric containing elastane was higher than the other two groups (2 and 3). In the 4th group, the increase in bending rigidity was caused by the increase in fabric weight. However, the effect of elastane was more dominant in the weft direction and therefore the increase in this direction was found to be insignificant. According to these results, it is not correct to conclude that elastane increases the bending rigidity in the warp direction.

The addition of elastane in Group 5 decreased the bending rigidity in the both directions, but the difference was significant only in the weft direction (p2=.01). The value (5.90 μNm) in the warp direction of the fabric with elastane was above the lower limit of the SiroFAST chart. However, its value in the weft direction (2.6 μNm) was very low and in the problematic zone. The warp yarn of this group contained 85% W− 15% NY fibers, while the weft yarn contained 42% W − 51% PES − 7% EA fibers. The insignificant effect of the use of elastane in the warp direction was considered to be due to the difference in fiber properties. In Group 6, elastane significantly increased the bending rigidity in both weft and warp directions (Table 4). However, only the value in the warp direction (15. 25 µN.m) was slightly above the upper limit value (15 µN.m) in the SiroFAST table.

When all the results were investigated, it was observed that the use of elastane increased the bending rigidity in weft and warp directions in the groups (1 and 6) with the heaviest fabric weights (290 g/m² and above). In these groups, the bending rigidity of the fabrics containing elastane was found to be the highest. This result is consistent with the results of the study investigating the elastic potential of wool and wool/man-made fiber blend fabrics (Geršac 2004). In addition, the bending rigidity values of the fabrics containing elastane were in the problem-free region in the warp direction. Weft direction values were in the problem-free zone only for groups 1, 4 and 6.

Formability results

Formability is a prominent factor in garment appearance, which in turn depends on initial modulus, tenacity, extensibility, and bending rigidity of fabrics (Behara and Mishra 2007). In the Siro FAST chart, values below 0.25 mm² cause the problem of seam pucker. Formability is calculated by the bending and extensibility values of the fabric in both directions (De Boss and Tester 1994). Therefore, while evaluating the formability results, the reasons for these results was also addressed. Figure 4 shows the formability results of fabrics.

Figure 4. Formability results of fabrics.

When the results of Group 1 were analyzed, it was seen that the addition of elastane increased the formability in both directions (Figure 4), but this increase was significant only in the weft direction (Table 4). The addition of elastane increased the formability value in the warp direction from 0.23 mm² to 0.62 mm² and in the weft direction from 0.82 mm² to 1.52 mm² (Figure 3). Thus, a possible seam-puckering problem in the warp direction was solved. The high bending rigidity value in the warp direction in this direction was effective on this result.

When the results of Group 2 were analyzed, it was seen that the effect of elastane addition on formability was significant in both directions (Table 4). However, it caused an increase in weft direction (0. 18 mm² −1.45 mm²) while it caused a decrease in warp direction (0.45 mm² − 0.16 mm²). Group 2 has the lowest fabric weight among the groups (Table 1). Low formability is an important problem in fabrics with low fabric weight (Wang, Postle, and Zhang 2003). The use of elastane reduced the bending rigidity of the fabric in this group in both directions, i.e. softened it. Therefore, the formability of this fabric has also become more difficult. However, the excessive extensibility value obtained in the weft direction of this group solved the problem by increasing the formability value in this direction.

In groups 3 and 4, the addition of elastane significantly increased the formability values of the fabrics in both directions and solved the seam puckering problem caused by low formability (Table 4). In the fourth group, the increase in bending rigidity in the warp direction was associated with an increase in the weight of the fabric with elastane. Nevertheless, in this group there was a significant increase in extensibility in the weft and warp direction due to the use of elastane. Therefore, the increase effect can also be attributed to elastane. However, the high value of the fabric with elastane (W8 = 0. 51) is due to the higher weight of this fabric.

The analysis of the results of group 5 showed that the use of elastane increased the formability in both directions, but this increase was significant only in the weft direction (p = .036). In the weft yarn of this group, 7% elastane was used and elastane significantly increased the extensibility in the weft direction (Table 3). Also, the effect of elastane on bending rigidity was insignificant in this direction. The formability results are due to these. In this group, although the formability of the fabric containing elastane in the warp direction increased, its value in the SiroFAST control table (0.23 mm²) remained just below the limit value.

When the results of Group 6 were analyzed, it was observed that the use of elastane significantly increased the formability values in weft and warp direction (Table 4). When the siroFAST results were examined, it was seen that the use of elastane increased the value in the warp direction from 0.10 mm² to 0.86 mm² and in the weft direction from 0.20 mm² to 1.19 mm². Elastane solved the problem of low formability in both directions and prevented seam puckering. The fabric weight of this group is high (290 gr/m²).In this group, elastane increased the bending rigidity in both directions and the bending rigidity values were quite high (Table 3). Therefore, the use of elastane significantly increased the formability in both directions.

One of the main functions that influence the behavior of a fabric in the garment making process and the suitability of the fabric for the garment is formability. This property is more important in the warp direction than in the weft direction in products such as structured jackets, because there are more seams in this direction (De Boss and Tester 1994). In this study, it was found that the addition of elastane improved the formability values in both the weft and warp directions of all groups except the formability value in the warp direction of the W4 (72%W/26%PES/2% EA) fabric in Group 2.

Shear rigidity results

Shear rigidity is one of the principle determinants, which is a measure of a fabric can be deformed into a three-dimensional shape. In the SiroFAST chart, the lower limit of shear rigidity is 30 N/m and the upper limit is 80 N/m. If the shear rigidity is less than 30 N/m the fabric is easily distorted and can skew or bow during handling, laying up, cutting, or sewing. This skewing can lead to the formation of distorted panels. If the shear rigidity is greater than 80 N/m, the fabric can be difficult to form, mould, or shape at the sleeve head and correspondingly difficult to form into smooth three-dimensional shapes (De Boss and Tester 1994; Thilagavathi and Viju 2013).

When the results were analyzed, it was seen that the addition of elastane decreased the shear rigidity in all groups except Group 6. In group 6, elastane significantly increased the shear rigidity, but the values of all fabrics containing elastane were below the lower limit (30 N/m) (Figure 5). The difference in the decrease in shear rigidity due to the use of elastane was statistically significant in Groups 2, 3, 4 and 5 (p < .05), but not in Group 1 (p = .56). The fabrics in groups 1 and 6 are heavy fabrics (Table 1). Due to the heavy weight of the fabrics, the effect of elastane was not sufficient to reduce the shear rigidity of the fabrics in these groups.

Figure 5. Shear rigidity results of fabrics.

Weight is a factor affecting the shear parameter of the fabric. Although the weights of the fabrics in Groups 1 and 6 were high, the fabric with elastane did not show the required shear rigidity value (Figure 5). This conclusion is in line with the results of Shanbeh et al. (2019). As a result, the use of elastane was found to reduce the shear rigidity of fabrics, except for heavy weight fabrics. Varghese and Thilagavathi (2014) attributed the decreasing effect in shear rigidity to the easy sliding of the fibers forming the structure on each other in elastane added fabrics.

Conclusions

In this study, the effects of the use of elastane on tailorability and appearance of 100% wool and different ratios of wool/polyester, wool/nylon and wool/polyester/nylon fiber blended woven suit fabrics were investigated. Although there were differences in the amount of elastane used in the weft yarn of the fabrics containing elastane in each group, it was observed that the effect of elastane varied mainly depending on the fabric weight. The use of elastane increased the bending rigidity in the weft and warp direction in the groups (groups 1 and 6) with the highest fabric weights (290 g/m² and above). In the other groups, the effect of elastane on the values in the weft and warp directions varied according to the type of fiber used in the weft and warp yarn and the weight of the elastane fabric. However, any problems were not observed in all warp direction values.

The use of elastane improved the appearance by increasing the weft and warp formability values in all groups except the warp direction value of the group with the lowest fabric weight (group 2). However, in the 5th group containing 7% elastane, it was observed that the increase in the warp direction was insignificant and this value was below the limit in the SiroFAST chart. Therefore, it was concluded that fabrics containing 7% or more elastane in the weft may have a seam puckering problem due to low formability in the warp direction. The highest formability values were obtained from the two groups with heavy fabric weight. Elastane was also found to reduce the shear rigidity except for these two groups. Therefore, it was concluded that the use of elastane, except for those with heavy weight, would cause distortion and skewing of the fabric during tailoring.

The effect of elastane on extensibility was seen to vary depending on fabric density, elastane content and fabric construction in addition to fabric weight. Low fabric weight and density resulted in excessive extensibility, which led to very poor tailorability.

Prominent results

Although there were differences in the amount of elastane used in the weft yarn of the fabrics containing elastane in each group, it was observed that the effect of elastane varied mainly depending on the fabric weight.

The use of elastane has been found to increase the bending rigidity of heavy weight fabrics (290 g/m² and above).

It was found that the use of elastane can cause fabric deformation during cutting and sewing, except for the heavy weight fabric groups due to its low shear rigidity.

The use of elastane improved the appearance by increasing the weft and warp formability values in all groups except the warp direction value of the group with the lowest fabric weight.

It was concluded that fabrics containing 7% or more elastane in the weft may have a seam puckering problem due to low formability in the warp direction.

Disclosure statement

No potential conflict of interest was reported by the author(s).