Investigation of bending and drape properties of woven fabrics and the effects of fabric constructional parameters and warp tension on these properties

Abstract

In this research, bending and drape properties of woven fabrics and the effect of weft density, weft yarn count and warp tension on these properties were investigated. Higher values were found for bending rigidities of the fabrics woven with thicker weft yarns and at higher weft densities. It was seen that bending rigidities of the fabrics in the warp directions increased as warp tension increased. Bending rigidities in the weft directions did not show any significant change, such as an increase or decrease depending on any change in warp tension. In the case of the fabrics woven with thicker weft yarns, the overall fabric bending rigidity increased as warp tension increased. Considering drape coefficients of the fabrics, it was observed that the drape coefficient increased as the weft density increased and weft yarn became thicker. The drape coefficient did not significantly vary depending on the variations in the warp tension.

Keywords

Bending drape woven fabric warp crimp weft crimp warp tension

‘Drape’ is a term used to describe the way a fabric hangs under its own weight. It has an important bearing on how good a garment looks in use.¹ Basically, fabric drape is not an independent fabric property. It depends on the fabric parameters, such as structure, yarn type and fiber content, as well as its finishing treatments. The study of objective evaluations of fabric drape started with Pierce,² who initiated research in fabric bending measurements using a cantilever test to assess two-dimensional drape. Chu et al.^3,4 developed the standard F.R.L. drapemeter for the measurement of three-dimensional drape. Cusick⁵ introduced a simple method to calculate the drape coefficient and found that it depends on both shear stiffness and bending length. Based on measurements from the drapemeter using Cusick’s principle, most researches reported the relationship between fabric drape and the values of mechanical properties obtained in the warp and weft directions.⁶ ^– ¹⁴ In general, bending, shearing and extension properties were shown to affect fabric drape.

Recently, several computer techniques have been developed or used for the simulation of fabric behavior.¹⁵ ^– ¹⁹ Vangheluwe and Kienkens¹¹ calculated the drape index using an image analysis technology, based on the number of pixels of the projected area of the draped fabrics. Wu et al.²⁰ used image analysis to simulate the mechanical properties of fabrics. Ruckman et al.²¹ integrated Cusick’s drapemeter principle with the image analysis technique to measure the static and dynamic drape of fabrics. Robson and Long²² evaluated drape by automatic characterization of drape profiles using an image analysis technique. The study establishes a strong correlation between the traditional cut and weight method of calculating the drape and the image analysis method.

Fabric bending rigidity is one of the most important factors influencing the handling and comfort of apparel; hence, the bending behavior of fabrics has received considerable attention in the literature. Since the 1930s fabric bending behavior has received much attention from scientists and has been widely investigated using different equipment based on the simple investigation of fabric deformation under its own weight, for example, the cantilever and loop methods^2,23,24 or more sophisticated methods measuring moment–curvature or force–angle relationships.²⁵ ^– ²⁷ In practice, the tools that are used to measure this property are the KES-FB2 and FAST-2 bending meter. The KES-FB2 pure bending tester measures bending rigidity per unit width and the hysteresis of the bending movement. The FAST-2 bending meter is based on Pierce’s bending length and measures a fabric’s two bending properties, namely the fabric bending length, which is related to the fabric’s ability to drape, and the fabric bending rigidity, which is related to the quality of stiffness when a fabric is handled.²⁸

Fabric bending rigidity is proportional to the fiber bending rigidity if all other factors about fabric construction, such as yarn count, yarn density, fabric pattern and finishing condition, remain the same. Studies showed that fabric density, yarn thickness and fabric pattern affect the bending rigidity of the fabrics. As the yarn density and thickness increased and the floating length of the yarns decreased, the bending rigidity of the fabrics increased.^1,29 ^– ³¹

There seems to be no doubt that tension during weaving has an important effect on the quality of the fabric. The effect of weft tension on physical properties of woven fabrics has been researched by Nosraty et al.³² In this study, a weft yarn tension controller was implemented in a single nozzle air jet loom for controlling the weft yarn tension variations during weft insertion. The fabric samples were woven with and without controlled weft yarn tension and their physical properties were measured. The results showed that the evenness of drape percentage of fabrics was affected by using the weft tension controller. The coefficient of variation (CV%) of fabric drape was decreased from 5.73% for fabrics woven in the uncontrolled weft yarn tension state to 3.0% for fabrics woven in controlled tension.

The purpose of the present work is to analyze bending and drape properties of woven fabrics; the effects of weft density, weft yarn count and warp tension on these properties are investigated.

Experimental details

In this study, 42 plain woven gray fabrics with different weft counts, weft densities and warp tensions were used. The fabrics were woven under controlled mill conditions. The type of warp and weft yarn, warp density (33 threads/cm) and warp yarn count (150 denier/36 filaments) remained the same. Twisted polyester (yarn twist of 350 turns/meter in the Z direction) warp yarn and cotton-carded ring-spun weft yarns are used in weaving fabrics. Warp tension is a parameter that represents the tension of all ends measured by the loom tension sensor. This parameter was entered from the machine computer and used to adjust warp tension by the tension control system of the air jet loom. The values of parameters changed for different fabric constructions are presented in Table 1.

Table 1.

Constructional parameters of the woven fabrics

Weft count	Warp tension (kN)	Weft density (threads / cm)
Nm 40.64 (Ne 24/1)	0.5	14/20/-
	1.0	14/20/-
	1.25	14/20/26
	1.5	14/20/26
	1.75	14/20/26
Nm 60.96 (Ne 36/1)	0.5	14/20/-
	1.0	14/20/26
	1.25	14/20/26
	1.5	14/20/26
	1.75	14/20/26
Nm 84.67 (Ne 50/1)	0.5	14/20/26
	1.0	14/20/26
	1.25	14/20/26
	1.5	14/20/26
	1.75	14/20/26

The test to determine the ‘Stiffness of fabric’ was carried out according to ASTM D1388,³³ using a stiffness tester. Before the tests, the samples were conditioned under laboratory conditions (25°C, 65% relative humidity (RH)). The tests were performed on each fabric sample at five replicas in both the warp and weft directions. Equation (1) was used to calculate the bending rigidities in the warp and weft directions:

(1)

where G is the fabric bending rigidity (mgcm), W is the weight per unit area (mg/cm²) and the bending length c is equal to half the length of the overhang (cm):

(2)

where G_o is the overall fabric bending rigidity (mgcm), G_w is the warp bending rigidity (mgcm) and G_f is the weft bending rigidity (mgcm).

The drape coefficient values of the fabrics were measured on the Cusick drapemeter according to ISO 9073-9.³⁴ The tests performed on each fabric sample for the five replicas and drape coefficient were determined. A low drape coefficient indicates easy deformation of a fabric and a high drape coefficient indicates less deformation.

It is well known that yarn crimp in a woven fabric is an important parameter that affects most of its physical properties. Therefore, warp and weft crimps in gray fabrics were measured according to the ASTM D3883-04³⁵ standard after the fabrics were conditioned under laboratory conditions.

Factor analysis of variance (ANOVA) was used to evaluate the influence of weft yarn count, weft density and warp tension on fabric bending rigidity and fabric drape coefficient. The p-values associated with F-tests for a three-way completely randomized ANOVA are presented in Table 2.

Table 2.

Analysis of variance (ANOVA) p-values for overall bending rigidities of the fabrics and drape coefficients of the fabrics (*** denotes the significance of the effect of the parameters on fabric overall bending rigidity and fabric drape coefficient; ns indicates that the factor is not significant; α = 0.05)

	ANOVA p-value
	Fabric’s overall bending rigidity	Fabric’s drape coefficient
Main effects
Weft count	0.0000***	0.0000***
Weft density	0.0000 ***	0.0000 ***
Warp tension	0.0000 ***	0.6000 ns
Interaction
Weft count x Weft density	0.0000***	0.0000***
Weft count x Warp tension	0.0000***	0.0000 ***
Weft density x Warp tension	0.0000***	0.0000 ***
Weft count x Weft density x Warp tension	0.0000***	0.0000***

Results and discussion

Fabric bending rigidity in the warp direction

Figures 1–3 show the bending rigidities of the fabrics in the warp directions according to the fabric constructional parameters and warp tension. As seen in the figures, as the weft density increases and the weft yarn becomes thicker, the bending rigidities of the fabrics in the warp directions increase. The highest bending rigidity in the warp direction was obtained in the fabric woven with a warp tension of 1.75 kN, with a weft yarn of Nm 40.64 (Ne 24/1), at a weft density of 26 threads/cm. The lowest bending rigidity in the warp direction was obtained in the fabric woven under a warp tension 0.5 kN, with a weft yarn of Nm 84.67 (Ne 50/1), at a weft density of 14 threads/cm.

Figure 1.

Bending rigidities of the fabrics in the warp direction for Nm 40.64 (Ne 24/1) weft yarn.

Figure 2.

Bending rigidities of the fabrics in the warp direction for Nm 60.96 (Ne 36/1) weft yarn.

Figure 3.

Bending rigidities of the fabrics in the warp direction for Nm 84.67 (Ne 50/1) weft yarn.

As is known, bending rigidities of fabrics depend on bending rigidities of the yarns that are used in their weaving, and the moving ability of weft and warp yarn in the fabric. As the yarn becomes thicker, the bending rigidity of the fabrics in that direction increases. In fabrics with a higher density, the relative mobility of fibers in the yarn or of yarns in the fabric is prevented and bending lengths of the fabrics become higher.³⁶ Therefore, in this study, as weft density increased, the bending rigidity of fabrics in the warp direction increased.

From the figures, it is seen that as warp tension increases, the bending rigidities of the fabrics in the warp direction increases. When warp tension was raised from 0.5 to 1.75 kN, a 30.2% and 48.8% increase in bending rigidity in the warp direction was observed in the fabric woven with Nm 40.64 (Ne 24/1) weft yarn, 14 threads/cm and 20 threads/cm, respectively. The same data for fabrics woven with weft yarn of Nm 60.96 (Ne 36/1) are 23.1% and 35.5%, respectively, and 17.5% and 33.5%, respectively, for the fabrics woven with a weft yarn of Nm 84.67 (Ne 50/1). When warp tension was raised from 1.25 to 1.75 kN, 13%, 4.2% and 8% bending rigidity in the warp direction increase was observed in the fabric woven with Nm 40.64 (Ne 24/1) weft yarn, 26 threads/cm, Nm 60.96 (Ne 36/1) weft yarn, 26 threads/cm and Nm 84.67 (Ne 50/1) weft yarn, 26 threads/cm, respectively. From a general point of view, the increase in bending rigidity in the warp direction is higher in fabrics woven with thicker weft yarns and/or at higher weft densities. Although a higher increase in bending rigidity in fabrics woven at a weft density of 26 threads/cm, in comparison with fabrics woven at other weft densities, was expected, it was seen that this increase was less than expected. The reason may be the fact that the evaluation was conducted for these fabrics between 1.25 and 1.75 kN, because fabrics could not be woven with all weft yarns and under all warp tension values at a weft density of 26 threads/cm.

Warp and weft crimps of all fabrics were measured to explain the difference between bending rigidities in the warp direction in these fabrics, which have the same structural parameters but are woven under different warp tensions. Results of the measurements are shown in Table 3. Considering these results, it was seen that as the warp tension increased, warp crimp decreased and weft crimp increased. Warp and weft yarns take on crimp when the shed is closed on a newly inserted weft yarn. When the warp yarns are closed on a newly inserted weft yarn, the newly inserted weft yarn is held by selvedge warps and the straight weft turns into a crimped form during beat up. Because of this, the weft yarn elongates and changes its cross section. At the same time, warp yarns between two wefts also elongate because of crimp. However, the elongation in warp yarns affects the entire warp length and, because of this, the increase in warp tension due to the crimp becomes less compared to the weft yarn.³⁷ This interaction between warp and weft yarns during fabric formation gives rise to the warp and weft crimp-tension relation . An increase in warp tension causes more pressure on the weft yarn and forces it to take more crimp and an increase in weft tension forces the warp yarn to take on more crimp. As a result of this relation, an increase in warp tension decreases warp crimp and an increase in weft tension decreases weft crimp. An increase in weft crimp with an increase in warp tension becomes greater when the weft yarn becomes thinner, and the weft density increases as the weft crimp level increases. Similarly, the decrease in warp crimp becomes greater with an increase in warp tension as the warp crimp level weft yarn becomes thicker, and weft density increases because of the increase in warp crimp level.

Table 3.

Warp and Weft crimps of the fabrics. Analysis of variance p-values for overall bending rigidities of the fabrics and drape coefficients of the fabrics (*** denotes the significance of the effect of the parameters on fabric’s overall bending rigidity and fabric’s drape coefficient; ns indicates that the factor is not significant, α = 0.05)

Weft count	Weft density (threads/cm)	Warp tension (kN)	Warp crimp (%)	Weft crimp (%)
Nm 40.64 (Ne24/1)	14	0.5	7.9	3.4
		1.0	7.6	3.8
		1.25	7.0	3.9
		1.5	6.7	4.0
		1.75	6.4	4.1
	20	0.5	10.4	3.8
		1.0	9.7	4.2
		1.25	9.2	4.1
		1.5	8.9	4.4
		1.75	8.3	4.7
	26	0.5	–	–
		1.0	–	–
		1.25	12.4	5.1
		1.5	11.6	5.4
		1.75	11	5.5
Nm 60.96 (Ne 36/1)	14	0.5	6.7	3.5
		1.0	6.1	3.8
		1.25	5.8	4.0
		1.5	5.6	3.9
		1.75	5.5	4.2
	20	0.5	7.6	3.8
		1.0	7.0	4.2
		1.25	6.6	4.5
		1.5	6.4	4.7
		1.75	6.2	4.8
	26	0.5	–	–
		1.0	9.3	4.7
		1.25	8.5	5.4
		1.5	8.1	5.5
		1.75	7.8	5.9
Nm 84.67 (Ne 50/1)	14	0.5	5.5	4.1
		1.0	5.2	4.3
		1.25	5.0	4.8
		1.5	4.8	5.0
		1.75	4.7	5.2
	20	0.5	6.3	4.6
		1.0	5.7	5.0
		1.25	5.6	5.4
		1.5	5.4	5.2
		1.75	5.2	6.0
	26	0.5	7.6	5.4
		1.0	6.6	5.9
		1.25	6.2	6.2
		1.5	5.8	6.6
		1.75	5.7	6.9

When warp tension was raised from 0.5 to 1.75 kN, the decrease in warp crimp, in fabrics woven with weft yarn of Nm 40.64 (Ne 24/1), was 18.9% with a weft density of 14 threads/cm and it occurred as 20.2% for the fabrics woven with weft yarn of Nm 60.96 (Ne 36/1), and as 14.5% for the fabrics woven with weft yarn of Nm 84.67 (Ne 50/1). When warp tension was raised from 0.5 to 1.75 kN, the decrease in warp crimp in fabrics woven with weft yarn of Nm 40.64 (Ne 24/1) was 20.2% with a weft density of 20 threads/cm, and it occurred as 18.4% for fabrics woven with weft yarn of Nm 60.96 (Ne 36/1), and as 16.1% for fabrics woven with weft yarn of Nm 84.67 (Ne 50/1). When warp tension was raised from 1.25 to 1.75 kN, the decrease in warp crimp in fabrics woven with weft yarn of Nm 40.64 (Ne 24/1) was 11.3% with a weft density of 26 threads/cm and it occurred as 8.2% for fabrics woven with weft yarn of Nm 60.96 (Ne 36/1), and as 8.1% for fabrics woven with weft yarn of Nm 84.67 (Ne 50/1). These results indicate that the decrease in the warp crimp, depending on the increase in the warp tension, generally increases when the weft yarn becomes thicker and weft density becomes higher. The decrease in warp crimp, which is seen in fabrics woven at a weft density of 26 threads/cm, may have occurred at a lower level due to the reason mentioned above. The fact that the crimp of warp yarns decreases as warp tension increases makes these yarns more resistant to bending in the fabric.³¹ As a result, higher bending rigidity in the warp direction was obtained in the fabrics woven under higher warp tension. The increase in bending rigidity in the warp direction occurred at higher levels in the fabrics in which the increase in warp tension caused a decrease in yarn crimp at higher levels (fabrics woven with thicker weft yarns and/or at higher weft densities).

Fabric bending rigidity in the weft direction

Figures 4–6 show the bending rigidities of the fabrics in the weft direction according to fabric constructional parameters and warp tension. As occurred in the case of bending rigidities in the warp direction, as the weft density increases and the weft yarn becomes thicker, the bending rigidities of fabrics in the weft direction increase.

Figure 4.

Bending rigidities of the fabrics in the weft direction for Nm 40.64 (Ne 24/1) weft yarn.

Figure 5.

Bending rigidities of the fabrics in the weft direction for Nm 60.96 (Ne 36/1) weft yarn.

Figure 6.

Bending rigidities of the fabrics in the weft direction for Nm 84.67 (Ne 50 1) weft yarn.

Bending rigidity in the weft direction did not show any significant change, such as an increase or decrease, depending on any change in warp tension, except the fabrics woven with weft yarns of Nm 60.96 (Ne 36/1) and Nm 84.67 (Ne 50/1) at a weft density of 26 threads/cm, in which bending rigidity in the weft direction decreased as warp tension increased. This decrease occurred as 3.8% for the fabrics woven with weft yarn of Nm 60.96 (Ne 36/1) and 5.9% for the fabrics woven with weft yarn of Nm 84.67 (Ne 50/1), as the warp tension was raised from 1.25 to 1.75 kN.

According to the weft crimp values of the fabrics in Table 3, it was seen that the increase in weft crimp occurred at higher levels depending on the increase in warp tension in the fabrics woven with thinner weft yarns and/or at higher weft densities. When warp tension was raised from 0.5 to 1.75 kN, the increase in weft crimp in fabrics woven with weft yarn of Nm 40.64 (Ne 24/1) was 20.6% with a weft density of 14 threads/cm, 20.0% for fabrics woven with weft yarn of Nm 60.96 (Ne 36/1), and as 26.8% for fabrics woven with weft yarn of Nm 84.67 (Ne 50/1). When warp tension was raised from 0.5 to 1.75 kN, the increase in weft crimp in fabrics woven with weft yarn of Nm 40.64 (Ne 24/1) was 23.7% with a weft density of 20 threads/cm, 26.3% for fabrics woven with weft yarn of Nm 60.96 (Ne 36/1), and as 30.4% for fabrics woven with weft yarn of Nm 84.67 (Ne 50/1). When warp tension was raised from 1.25 to 1.75 kN, the increase in weft crimp in fabrics woven with weft yarn of Ne Nm 40.64 (Ne 24/1) was 7.8% with a weft density of 26 threads/cm, 9.3% for fabrics woven with weft yarn of Nm 60.96 (Ne 36/1), and as 11.3% for fabrics woven with weft yarn of Nm 84.67 (Ne 50/1). Despite the interpretation above, the increase in percentage weft crimp in the fabrics woven at a weft density value of 26 threads/cm occurred at lower levels compared with the increase in crimp in percentage, which was seen in the fabrics woven at weft densities of 14 and 20 threads/cm. The reason may be the fact that the evaluation was conducted for these fabrics between 1.25 and 1.75 kN, because fabrics could not be woven with all weft yarns and under all warp tension values at a weft density of 26 threads/cm.

The increase, which occurred at higher levels in the weft crimp, reduced resistance of the weft yarns in the fabric to bending, especially in the case of fabrics woven with thinner weft yarns and/or at higher weft densities.³¹ This caused a reduction in bending rigidities of these fabrics in the weft direction.

Overall fabric bending rigidity

Figures 7–9 show graphically the overall bending rigidities of the fabrics. According to the graphics, overall bending rigidities increase as the weft yarn becomes thicker and weft density becomes higher, as expected. Overall bending rigidities of the fabrics woven with a weft yarn of Nm 40.64 (Ne 24/1) increased as the warp tension increased, while this increase occurred at lower levels in the fabrics woven with a weft yarn of Nm 60.96 (Ne 36/1). Any significant variation was not observed in the overall bending rigidities of the fabrics woven with a weft yarn of Nm 84.67 (Ne 50/1), despite the increase in warp tension.

Figure 7.

Overall fabric bending rigidity for Nm 40.64 (Ne 24/1) weft yarn.

Figure 8.

Overall fabric bending rigidity for Nm 60.96 (Ne 36/1) weft yarn.

Figure 9.

Overall fabric bending rigidity for Nm 84.67 (Ne 50/1) weft yarn.

Overall fabric bending rigidity is a geometrical mean of bending rigidity in the warp direction and bending rigidity in the weft direction. Particularly in the case of fabrics woven with weft yarns of Nm 40.64 (Ne 24/1) and Nm 60.96 (Ne 36/1), as warp tension increased, bending rigidity in the warp direction increased, while any significant variation was not observed in bending rigidity in the weft direction depending on the increase in warp tension and, therefore, variations in bending rigidity in the warp direction and in overall fabric bending rigidity occurred similarly, depending on the change in the warp tension. The increase in bending rigidity in the warp direction of the fabrics woven with a weft yarn of Nm 84.67 (Ne 50/1), depending on the increase in the warp tension, was observed at lower levels compared with the increase that occurred in bending rigidities in the warp direction of the fabrics woven with other weft yarns, while bending rigidity in the weft direction did not vary significantly as the warp tension increased, except for the fabrics woven with a weft density of 26 threads/cm and, therefore, overall fabric bending rigidity did not vary significantly despite a very insignificant increase. In the case of fabrics woven with a weft yarn of Nm 84.67 (Ne 50/1) at a weft density of 26 threads/cm, as the warp tension increased, bending rigidity in the warp direction increased (8.0%), while bending rigidity in the weft direction decreased (5.9%) more compared with other densities and these values are close to each other. Thus, overall fabric bending rigidity did not vary significantly in these fabrics.

Drapability

Figures 10–12 show graphically drape coefficients (DC%) of the fabrics, which were woven at different weft counts, weft densities and warp tensions.

Figure 10.

Drape coefficients of the fabrics for Nm 40.64 (Ne 24/1) weft yarn.

Figure 11.

Drape coefficients of the fabrics for Nm 60.96 (Ne 36/1) weft yarn.

Figure 12.

Drape coefficients ofthe fabrics for Nm 84.67 (Ne 50/1) weft yarn.

According to the graphics, it was observed that drape coefficients of the fabrics increased as the weft density increased and the weft yarn became thicker. The highest drape coefficient was observed for the fabric woven with a weft yarn of Nm 60.96 (Ne 36/1) under the warp tension of 1.0 kN at a weft density of 26 threads/cm (DC = 84.3%), while the lowest drape coefficient was observed for the fabric woven with a weft yarn of Nm 60.96 (Ne 36/1) under the warp tension of 0.5 kN at a weft density of 14 threads/cm (DC = 67.1%). Drape coefficients of other fabrics ranged between these two values. Drape coefficients of the fabrics did not vary significantly in a certain way in response to any variation in the warp tension.

Figure 13 shows graphically the relationship between overall bending rigidities and drape coefficients of the fabrics for different warp tensions. As seen in Figure 13, the drape coefficient of the woven fabric has a close correlation with fabric bending rigidity. Fabrics with higher bending rigidities have higher drape coefficients and less draping properties. The bending rigidities and drape coefficients of the fabrics woven with thicker weft yarns and higher weft densities were also found to be higher in this study. Correlation coefficients between bending rigidities and drape coefficients of the fabrics were obtained between 0.86 and 0.96 for different warp tensions.

Figure 13.

Relationship between overall bending rigidities of the fabrics and drape coefficients of the fabrics.

ANOVA p-values for overall bending rigidities of the fabrics and drape coefficients of the fabrics are presented in Table 2. According to the statistical analysis, weft count, weft density and warp tension have a significant effect on fabric overall bending rigidity. Weft count and weft density have a significant effect on fabric drape coefficient, while the effect of the warp tension on fabric drape coefficient is insignificant.

Conclusions

This study was conducted to investigate drape and bending properties of gray plain woven fabrics and the effect of weft density, weft yarn count and warp tension on these properties. Warp and weft yarn type, warp count and warp density were kept constant, while weft count, weft density and warp tension were varied in manufacturing of the fabrics. At the end of the study, higher values were found for bending rigidities of the fabrics woven with thicker weft yarns and at higher weft densities in the warp, weft and overall bending rigidities.

It was seen that bending rigidities of the fabrics in the warp direction increased as warp tension increased. This increase occurred at higher levels in fabrics woven with thicker weft yarns and at higher weft densities. Considering warp crimps of these fabrics, having the same structural parameters but woven under different warp tensions as the only exception, warp crimp decreased as warp tension increased. This made these yarns more resistant to bending in the fabric and, thus, higher bending rigidity was achieved in the warp direction.

Bending rigidity in the weft direction did not show any significant change, such as an increase or decrease depending on any change in warp tension. In the case of fabrics woven with thinner weft yarns at a weft density of 26 threads/cm, bending rigidity in the weft direction decreased as the warp tension increased. This decrease was explained depending on the increase in weft crimp versus the increase in the warp tension in the case of fabrics woven with thinner weft yarns and/or at higher weft densities. The increase, which occurred at higher levels, in the weft crimp, reduced resistance of the weft yarns in the fabric to bending, especially in the case of fabrics woven with thinner weft yarns and/or at higher weft densities. This caused a reduction in bending rigidity of these fabrics in the weft direction.

Overall fabric bending rigidity is the geometrical mean of bending rigidity in the warp direction and bending rigidity in the weft direction. In the case of fabrics woven with thicker weft yarns, as warp tension increased, overall fabric bending rigidity increased. The increase in bending rigidity in the warp direction of the fabrics woven with the thinnest weft yarn, except those woven with a weft density of 26 threads/cm, depending on the increase in the warp tension, increased at lower levels compared with the increase that occurred in bending rigidities of the fabrics woven with other weft yarns, while bending rigidity in the weft direction did not vary significantly as the warp tension increased and, therefore, overall fabric bending rigidity did not vary significantly despite a very insignificant increase.

Considering drape coefficients of the fabrics, it was observed that the drape coefficient increased as the weft density increased and weft yarn became thicker. The drape coefficient did not significantly vary depending on the variations in the warp tension. This study has evidenced once more that the effect of the bending rigidity of a fabric on its drape feature is quite significant. In this study, the fabrics woven with thicker weft yarns at higher weft densities gave higher bending rigidities and drape coefficients.

Footnotes

Funding

This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors.

References

Saville

. Physical testing of textiles. Cambridge: Woodhead, 2000. 310–310.

Pierce

. The handle of cloth as measurable quantity. J Text Inst 1930; 21: 377–416.

Chu

Cummings

Teixeira

. Mechanics of elastic performance of textile materials, part V: A study of the factors affecting the drape of fabrics the development of a drape meter. Textil Res J 1950; 20(8): 539–548.

Chu

Platt

Hamburger

. Investigation of the factors affecting the drapability of fabrics. Textil Res J 1960; 30(1): 66–67.

Cusick

. The measurement of fabric drape. J Text Inst 1968; 59(6): 253–260.

Hearle

JWS

Amirbayat

. Analysis of drape by means of dimensional groups. Textil Res J 1986; 56: 727–733.

Collier

. Measurement of fabric drape and its relation to fabric mechanical properties and subjective evaluation. Cloth Textil Res J 1991; 10(1): 46–52.

Collier

Paulins

Collier

. Effects of interfacing type on shear and drape behaviour of apparel fabrics. Cloth Textil Res J 1989; 7(3): 51–56.

Morooka

Niwa

. Relation between drape coefficients and mechanical properties of fabrics. J Textil Mac Soc Jpn 1976; 22(3): 67–73.

10.

Niwa

Seto

. Relationship between drapability and mechanical properties of fabrics. J Textil Mac Soc Jpn 1986; 39(11): 161–168.

11.

Vangheluwe

Kiekens

. Time dependence of the drape coefficient of fabrics. Int J Cloth Sci Technol 1993; 5(5): 5–8.

12.

Jeong

. A study of fabric drape behavior with image analysis, part I: Measurement, characterization and instability. J Text Inst 1998; 89(1): 59–69.

13.

Jeong

Philips

. A study of fabric drape behavior with image analysis, part II: The effect of fabric structure and mechanical properties on fabric drape. J Text Inst 1998; 89(1): 70–79.

14.

Okur

Cihan

. Prediction of fabric drape coefficients from FAST data. Textil Asia 2002; 33(7): 28–31.

15.

. Structure and mechanics of woven fabrics. Cambridge: Woodhead, 2004. 307–307.

16.

Collier

O’Toole

. Drape prediction by means of finite-element analysis. J Text Inst 1991; 82(1): 96–107.

17.

Jevsnik

Gersak

. Modelling a fused panel for a numerical simulation of drape. Fibres Textil East Eur 2004; 12: 47–52.

18.

Kobza

. Optimisation of the plane draping process. Fibres Textil East Eur 1996; 14–15: 43–48.

19.

Szablewski

Kobza

. Numerical analysis of Peirce’s cantilever test for the bending rigidity of textiles. Fibres Textil East Eur 2003; 43: 54–57.

20.

Yuen

. Mechanical properties of fabric materials for draping simulation. Int J Cloth Sci Technol 2003; 15(1): 56–68.

21.

Ruckman

Cheng

Murray

. Dynamic drape measuring system. Int J Cloth Sci Technol 1998; 10(6): 56–56.

22.

Robson

Long

. Drape analysis using imaging techniques. Cloth Textil Res J 2000; 18(1): 1–8.

23.

Cassidy

Cassie

. The stiffness of knitted fabrics: A new approach to the measurement of bending. Part 1: Development. Int J Cloth Sci Technol 1991; 3(5): 14–19.

24.

Mete

Lloyd

. Modelling the “CLOACK” test: an example of two-dimensional elastica theory. Int J Cloth Sci Technol 2000; 12(4): 255–264.

25.

Kawabata

Niwa

. Objective measurement of fabric mechanical property and quality: Its application to textile and clothing manufacture. Int J Cloth Sci Technol 1991; 3: 7–18.

26.

Livsey

Owen

. Cloth stiffness and hysteresis in bending. J Text Inst 1964; 55(10): 516–530.

27.

Abbott

Grosberg

. Measurement of fabric stiffness and hysteresis in bending. Textil Res J 1966; 36(10): 928–930.

28.

Miroslawa

Witold

Izabella

. Evaluating the bending rigidity of flat textiles with the use of an Instron tensile tester. Fibres Textil East Eur 2005; 13(2): 31–34.

29.

Alpay

Kavusturan

. Factors affecting the bending behavior of cotton woven fabrics. Tekstil Maraton 2000; 5: 56–61.

30.

Matsudaira

Tan

Kondo

. The effect of fibre cross-sectional shape on fabric mechanical properties and handle. J Text Inst 1993; 84(3): 376–386.

31.

Omeroglu

Karaca

Becerir

. Comparison of bending, drapability and crease recovery behaviors of woven fabrics produced from polyester fibers having different cross-sectional shapes. Textil Res J 2010; 80(12): 1180–1190.

32.

Nosraty

Jeddi

AAA

Kabganian

. Influence of controlled weft yarn tension of a single nozzle air-jet loom on the physical properties of the fabric. Textil Res J 2006; 76(8): 637–645.

33.

ASTM D1388-96:2002. Standard test method for stiffness of fabrics.

34.

ISO 9073-9:2008. Textiles- test methods for nonwovens – part 9: Determination of drapability including drape coefficient.

35.

ASTM D1388-04:2008. Standard test method for yarn crimp and yarn take-up in woven fabrics.

36.

Cooper

. The stiffness of woven textiles. J Text Inst 1960; 51(3): 317–335.

37.

Greenwood

. Weaving: Control of fabric structure. Durham: Merrow Publishing, 1975. 25–30.