Analysis the Influenced of Plain and Twill Structures on Woven Fabric Properties

Fabric outer appearance is influenced by various fabric structures. In this research work, the physical properties of plain and twill were analyzed. Physical, mechanical and other aesthetic properties are also tested and the finding results are also compared between two samples. After testing the samples it is found that rubbing fastness remains unchanged for plain and twill fabric. Abrasion resistance, pilling, crease recovery and cover factor were evaluated for twill and plain structures using ISO 12945-2, ISO 12945-1 and ISO 2313 methods respectively. Abrasion resistance and pills property are not good for twill fabric in comparison with plain fabric but crease recovery is better of twill fabric.

Journal of Textile Science and Technology woven fabric is required for export every year but only about forty-five million meters of woven fabric is exported by us. This scenario showed the lacking of our woven fabric industry. For that it is essential to establish more and more woven factories to reduce the gap between supply and demand [2].
Woven fabric is produced by the interlacement of warp yarn that is longitudinal and weft yarn that is transverse and it is the most versatile fabric for its construction. It is the most sophisticated & aristocratic fabric available with different designs. Plain, twill, satin etc. can be produced by variation of the interlacement of warp and weft yarn. These variations of the designs have changed mechanical properties of woven fabrics. For textile fabric it is described as a result of the material's resistance to the activity of external forces causing the change of shape [3]. As the properties of fabric vary according to their weave structure, we have taken two structures of woven fabric such as 1/1 plain and 3/1 Z twill to analyze the influence of plain and twill structures on woven fabric properties.
Plain weave is the basis of three fundamental types of textile weaves (along with satin weave and twill). In plain weave cloth, the warp and weft threads cross at right angles. Each weft thread crosses the warp threads by going over one, then under the next, and so on. The next weft thread goes under the warp threads that its neighbor went over, and vice versa [4]. Twill is a type of textile weave with a pattern of diagonal parallel ribs. It is one of three fundamental types of textile weaves along with plain weave and satin. It is made by passing the weft thread over one or more warp threads then under two or more warp threads and so on, with a "step", or offset, between rows to create the characteristic diagonal pattern [5].
The aim of this study is to identify the influence of plain and twill structures on woven fabric properties. From literature it is possible to detect that due to variation of fabric construction, the mechanical properties of the fabric also vary.
Among various properties, for this experiment abrasion resistance, pilling resistance, crease recovery and cover factor of two different types of fabric designs were tested [6].

Testing Procedure of Pilling Formation (ISO 12945-1)
For this test four specimens each 5 inch × 5 inch were cut from the fabric. A seam allowance of 12 mm was marked on the back of each square. In two of the samples the seam was marked parallel to the warp direction and in the other two parallel to the weft direction. The samples were then folded face to face and a seam was sewn on the marked line. This gave two specimens with the seam parallel to the warp and two with the seam parallel to the weft. Each specimen was turned inside out and 6 mm cut off each end of it thus removing any sewing distortion. The fabric tubes made were then mounted on rubber tubes so that the length of tube showing at each end was the same. Each of the loose ends was taped with poly (vinyl chloride) (PVC) tape so that 6 mm of the rubber tube was left exposed. All four specimens were then placed in one pilling box. The samples were then tumbled together in a cork-lined box. The usual number of revolutions used in the test was 18,000 which take 5 hrs [8]. The specification of the machine was Brand: James Heal; Origin: UK; Model: 1516 ORBITOR; Volts: 110 -230 V; Frequency: 50/60 Hz; Amp: 0.5 A; S/N: 1516/2/1014.

Testing Procedure of Crease Recovery (ISO 2313)
A specimen was cut from the fabrics with a template 2 inch long by 1 inch wide. It was carefully creased by folding in half placing it between two glass plates and adding a 2 kg weight. After 1 min the weight was removed and the specimen transferred to the fabrics clamp on the instrument and allowed to recover from crease. As it recovers, the dial of the instrument was rotated to keep the free edge of the specimen in line with the knife edge. At the end of the time period allowed for recovery, usually 1 min the recovery angle in degrees was read on the engraved scale. Warp and weft way recovery were reported separately to the nearest degree from the mean values of ten tests in each direction [9].

Testing Procedure of Cover Factor
Cover factor is a number that indicates the extent to which the area of a fabric is covered by one set of threads. For any woven fabric, there are two cover factors: a warp cover factor and a weft cover factor. Under the cotton system, the cover factor is the ratio of the number of threads per inch to the square root of the cotton yarn count. It is calculated by the following formula 1 2 1 2 28 where, K c = Cloth cover factor K 1 = Warp cover factor = EPI/Warp count K 2 = Weft cover factor = PPI/Weft count [10].

Testing Procedure of Color Fastness to Rubbing (ISO 105-X12)
Rubbing fastness is the resistance to fading of dyed textiles when rubbed against a rough surface. This test determines the fastness of dyestuff to either wet or dry rubbing. For rubbing fastness testing test specimen 15 cm × 5 cm was placed on the base of the crock meter. Square of white test cloth (5 cm × 5 cm) of cotton desized, bleached but without finish was attached to the finger of the crock meter. This finger was used in rubbing action on the sample specimen i.e. rubbing 10 cm long to and fro 10 times at 10 seconds. 20 rubs in 10 s and finger pressure on the specimen was 9 N. For testing dry and wet rubbing separate specimen was used. Three specimens for dry and wet rubbing respectively in warp way direction and another three specimens for both rubbing respectively in weft direction were used for two different constructed samples. Change in color in the specimen and staining in the white cloth was determined by grey scale.

Determination of Abrasion Resistance
The wear index indicates the abrasion resistance of both of the fabrics. The more the wear index (Table 1) indicates lower abrasion resistance properties. From the tables we can see that the average wear index (Table 2) of plain fabric is less than the twill fabric.
Due to less interlacement or more porous, twill weave is not so resistant to abrasion compares to plain.

Determination of Pilling
From Table 3, it's clear that the pill formation tendency of twill fabric is more  than the plain fabric. Due to less interlacement the migratory tendency of fibers from the constituent yarn is less in plain weave than twill. As a result, it is found that plain fabric is more resistant to pill formation than twill weaves. Table 4 shows the comparative crease angle.

Determination of Fabric Crease Recovery
After completing the test we found crease recover angle (Table 4) of plain fabric is 105˚ and twill fabric is 110˚. So the crease formation of plain is much higher than twill fabric.
Due to the increase of the weft yarn count, the crease recovery angle increases for all types of weave structures.

Determination of Cover Factor
The comparative result of cloth cover is given in Table 5. The more the cloth cover the more compact the fabric will be. Here the cloth cover of plain fabric (22.65) is greater than the cloth cover of twill fabric (21.26). So the plain fabric is more compact.

Determination of Color Fastness to Rubbing
The comparative grey scale rating is given below.
From Table 6 it is seen that both of the fabric show good rubbing properties.

Conclusion
In this study, elaborate knowledge about the variation of mechanical properties (abrasion resistance, pilling resistance, crease recovery, color fastness to rubbing, cover factor) on the fabric structure of woven fabric was studied. After examination, we found that twill fabric has more wear index than plain fabric. Plain fabric has lower tendency to form pills in comparison with twill fabric. But crease