The Assessment of Finishing Properties on the Mass per Unit Area, Pilling, Bursting Strength, and Wicking Behavior of Polyester Weft-Knitted Jersey Fabric

: Finishes bring an alteration to the physical and comfort properties of the textiles. That’s why various ﬁnishes are used to impart various functionalities to the fabric surface. However, it may also a ﬀ ect some properties. The purpose of this study is to investigate the e ﬀ ect of various ﬁnishes on pilling, mass per unit area, bursting strength, and wicking behavior of the polyester weft-knitted jersey fabric. Herein, 100% spun polyester weft-knitted plain jersey fabric was exposed to di ﬀ erent ﬁnish treatments to check their e ﬀ ect on the some physical and comfort properties of the fabric like mass per unit area, pilling behavior, bursting strength, and wicking properties of the weft-knitted jersey fabric. The fabric used was knit from 24 / 1, 100% spun polyester yarn on the single knit circular knitting machine. The developed fabric was washed on Fong machine. Finishes are applied on fabric by “Monofort Stanter” machine. The resultant fabric was characterized by random tumble pilling tester, bursting strength tester, and wicking tester to analyze their pilling grade, bursting strength, and wicking behavior respectively. A signiﬁcant increase has been found in wicking behavior, mass per unit area, and bursting strength of the fabric after ﬁnishing treatments. Moreover, the wicking ﬁnish shows the highest reduction in pilling grade from 3.5 to 2.5. Signiﬁcant improvement has been observed in bursting strength by all ﬁnish’s treatment. However, wicking ﬁnish treatment results in the highest increase in bursting strength of 4.2%. Signiﬁcant improvement has been observed in the vertical wicking speed of all treatment except silicon ﬁnish which signiﬁcantly reduces vertical wicking rate. However, the wicking ﬁnish (Recipe E) shows the highest increase in wicking rate by 13.75 times as compared to grey fabric.


Introduction
Polyester fabric is widely used in our daily life for casual and sportswear applications. Various finishes are added to impart some specific functionality. Finishes also bring an alteration to the physical and comfort properties of the textiles. Therefore, it is important to check the effect of such finishes on some other properties like pilling, bursting strength, wicking behavior, and dimensional stability of the fabric. Pilling is an unwanted effect on the fabric surface caused by the protruding fibers of the Wicking plays a key role in the comfort of any fabric. It has the ability of a fabric to evaporate moisture. Canen et al. investigated the comfort properties of compression garments. He studied the effect of elastane composition on the vertical wicking of single jersey plaited knitted fabric. The results show that by increasing in elastane composition percentage the vertical wicking of the fabric also increases. Moreover, they also investigated the effect of process tension on the vertical wicking of the fabric. The results reveal that low tension during the manufacturing process results in higher wicking as compared to higher tension [22]. Ikilem et al. conducted a study on the effect of Lycra percentage and some finishing treatments on vertical wicking behavior of seamless garments. They used conventional polyamide and meryl skinlife fibers for the manufacturing of fabric. The results expose that vertical wicking of the fabric significantly increases by increasing Lycra percentage. Moreover, applying antibacterial finishes causes reduction in vertical wicking rate because the yarn surface was all covered by finishing agents hence the water transport behavior also changed [23]. Yuliang et al. studied the incorporation of ZnO into Polyvinylidene fluoride (PVDF) and Polyacrylonitrile (PAN) nanofibers. The effect of hybrid PVDF/PAN/ZnO nanocomposite was investigated on antibacterial and wicking behavior. Significance reduction in vertical wicking of the nanocomposite has been observed by the incorporation of ZnO nanorods because it blocks pores available on the surface which affects vertical wicking speed [24].
Our local industries are facing a lot of challenges that significantly affect their production targets and business growth. One of the challenges is the lack of technical literature availability for a huge number of dyes and chemicals. Most of the time industries go for several trials to get some data for some specific finishes which needs a lot of time and huge financial resources. The current study was held to perform various trials of applying different finishes on 100% spun polyester weft-knitted jersey fabric and investigate their effect on the physical and comfort properties of the fabric. Herein, the effect of various finishes and washing treatments on the mass per unit area, pilling tendency, bursting strength, and wicking behavior of the 100% spun polyester weft-knitted plain jersey fabric has been investigated. Polyester fiber is widely used recently due to its low cost and ease of availability and its use is also increasing very rapidly. Industries are using different finishes on fabric to impart various functionality to achieve customer desire properties. Finishes provided by the manufacturer do not have technical literature which tells about the effect of such finishes on the properties of the fabric like pilling, bursting strength, areal density, and wicking behavior of the fabric. Hopefully, this study will help the users in a better selection of suitable finishes for imparting specific functions without compromising on other properties. This study will provide technical data to the industries about the few wet treatment recipes and their impact on various properties. Data of this study will save the time and financial resources of the industries.

Materials and Methods
Herein, polyester fibers were purchased from Ibrahim Fibers limited Pakistan, and the 24/1 100% spun polyester yarn manufacturing was carried out by a ring spinning machine. A 100% spun polyester weft-knitted jersey fabric was knitted on an 18/22 diameter/gauge circular knitting single jersey machine. The specifications fibers, yarn, knitting machine, and fabric are shown in Table 1. The developed fabric is exposed to different wet processing finishing treatment as shown in Table 2.  The developed fabric was cut into five pieces and marked on both sides for easy identification. One sample is considered as a reference while the remaining were exposed to various treatments as shown in Table 2. As wide practice of industries, fabric is exposed to washing treatment before dying to remove stains and oil spots in order to achieve better and uniform dying results. For this purpose, a recipe containing chemicals, e.g., Felosin RCN detergent and Diavan PCV, was prepared. Fabric was loaded to a Founge washing machine at 60 • C temperature for 20 min. Later the sample was exposed to a Hydro machine for removing water. Macro-emulsion of silicon oil based Sarofin SMT (Chem-Tech international) is used as softeners for improving softness and hand feel of the fabric. A recipe of acetic acid (local), Polyavin PEN (CHT R.Beitlich GMBH Germany) and Megasil MT (Chem-Tech International) were applied on the fabric via a Santex machine (Swiss Textile Machinery, Zurich, Switzerland). Furthermore, in order to enhance the wicking behavior of the fabric a recipe of acetic acid (local), Rucofin GSQ 200 (Rudolf Chemie), and Reapert SR New (Bozzetto group) were Coatings 2020, 10, 723 5 of 12 applied on the fabric and then exposed to Monofort stanter at 120 • C for 90 s to remove moisture. Moreover, normal finish contains recipe acetic acid (local), Foung lube and Polyavin PEN were applied in order to enhance hand feel of the developed sample.

Mass per Unit Area
Mass per unit area is the key parameter of the knitted fabric for the negotiation between supplier and buyer. Therefore, it is very important to control it through various possible parameters. GSM cutter method was used to calculate the mass per unit area of the fabric. The first fabric was cut via GSM cutter of size 112 mm 2 by following ASTM-D-3776 [25]. The weight of the cut fabric sample was done through digital weight balance. The mass per unit area (GSM) of fabric was calculated by Equation (1).

Pilling Test
Pilling is an unwanted effect on the fabric surface caused by protruding fiber. It is very common in knitted fabrics due to fabric loose structure and the use of low twist yarn. Firstly, samples were cut in the size of 10.16 × 10.16 cm 2 . Pilling test of all samples was performed on random tumble pilling tester by ASTM-D-3512 standard [26]. As per standard procedure, samples were kept in random tumble pilling tester for 30 min. The pilling grade was evaluated by a standard replica having grades ranged from 5 to 1, which represents very good to poor, respectively.

Bursting Test
Bursting strength refers to the perpendicular force required to break or rupture the fabric. To investigate the bursting strength of the fabric, the sample was cut in the size of 112 mm 2 by using the standard method of ASTM-D-3786 [27]. Resulted samples were clamped over a rubber diaphragm and a diaphragm bursting strength tester was used for calculating the value of bursting strength. During testing cut samples were clamped over the rubber diaphragm and increasing fluid pressure was applied to the fabric until it burst. Noted the value of pressure against each sample.

Vertical Wicking Test
To investigate the wicking behavior, vertical wicking tester was used, and the sample was cut in the size of 165 × 25 mm 2 in both wales wise and course-wise direction. The resultant wale-wise samples were hanged vertically in wicking machine such that the 0.5 mm length of samples dips in the water and note the time. After 30 min, samples were removed from the water and measure the total length to which water is traveled. The wicking speed of samples was measured by Equation (2). The same steps were repeated to investigate the wicking behavior of course-wise samples.
Wicking Speed = (Distance traveled by water in mm/Total time in min) (2)

Yarn Testing
Yarn quality was tested by UT-5 (S-400). The count was measured by wrapping the yarn over the reel and weight balance method. Moreover, the twist of the yarn was measured by the untwisting and re-twist method.

Effect of Finishes Treatment on the Mass per Unit Area
During fabric manufacturing, the yarns are under high tension. Later, when the fabric is wet in a tensionless condition the relaxation occurs and the course-wise and wale-wise dimensions become shortened. Therefore, the capability of the shrinkage rate for various treatments would be a significant advantage. Moreover, the mass per unit area has a direct relation with fabric shrinkage. When the fabric is exposed to any type of wet processing treatment it undergoes some shrinkage. When fabric shrink it alters some other properties as well. Different wet processing treatments undergo different shrinkage. The results of this study reveal that the mass per unit area of the fabric is increased by all recipe treatments B, C, D, and E as shown in Figure 1 and Table 3. However, treatment D and E record the highest increase in mass per unit area. As single jersey fabric has unstable structure and all types of wet treatments undergo relaxation of internal stresses produced in the loops and fibers during the knitting process and yarn manufacturing process, respectively. Such relaxation of fibers and loops is responsible for shortening the fabric in both the wale-wise and course-wise dimensions. In other words, we can call it shrinkage of the fabric. That's why wet treatment of the fabric cause to increase in the mass per unit area. Due to shrinkage, the structure of the fabric becomes more compact and mass per unit area also increases [28].

Effect of Finishes Treatment on the Mass per Unit Area
During fabric manufacturing, the yarns are under high tension. Later, when the fabric is wet in a tensionless condition the relaxation occurs and the course-wise and wale-wise dimensions become shortened. Therefore, the capability of the shrinkage rate for various treatments would be a significant advantage. Moreover, the mass per unit area has a direct relation with fabric shrinkage. When the fabric is exposed to any type of wet processing treatment it undergoes some shrinkage. When fabric shrink it alters some other properties as well. Different wet processing treatments undergo different shrinkage. The results of this study reveal that the mass per unit area of the fabric is increased by all recipe treatments B, C, D, and E as shown in Figure 1 and Table 3. However, treatment D and E record the highest increase in mass per unit area. As single jersey fabric has unstable structure and all types of wet treatments undergo relaxation of internal stresses produced in the loops and fibers during the knitting process and yarn manufacturing process, respectively. Such relaxation of fibers and loops is responsible for shortening the fabric in both the wale-wise and course-wise dimensions. In other words, we can call it shrinkage of the fabric. That's why wet treatment of the fabric cause to increase in the mass per unit area. Due to shrinkage, the structure of the fabric becomes more compact and mass per unit area also increases [28].

Effect of Finishes Treatment on the Pilling of the Fabric
The average pilling results of all the samples are exhibited in Table 4 and Figure 2. Treatment of fabric sample with recipe B cause deteriorate pilling grade from 3.5 to 2.5. Recipe C treated fabric shows half grade deterioration in the pilling grade from 3.5 to 3. As treatment D is considered it causes to reduce the pilling resistance. In terms of grades, it shows reduction in pilling grade from 3.5 to 3. Lastly, the treatment of the fabric with recipe E also causes to reduce piling grade from 3.5 to 2.5. To sum up, recipes B, C, D, and E showed a decrease in pilling resistance and pilling rating of the fabric. However, the results of the recipes C and D are comparatively appreciable which caused half grade deterioration in pilling as shown in Figure 2 and Table 4. On the other hand, recipes B and E caused the highest deterioration by one grade. The above results could be explained that during such treatments, the fraction between fabric and machines possibly caused to damage the surface fibers. Secondly, washing and finishing treatments caused increased wales and course density hence, yarns in the fabric come closer to each other. It causes to increase more protruding fiber per unit areas than untreated fibers, hence more pills appear per unit area [13]. Moreover, it is due to the ability of these softeners and finishes to reduce fiber to fiber friction by increasing individual fiber lubrication, thus, facilitating the fibers coming out of the main body of the fabric to form pills [13].

Effect of Finishes Treatment on the Pilling of the Fabric
The average pilling results of all the samples are exhibited in Table 4 and Figure 2. Treatment of fabric sample with recipe B cause deteriorate pilling grade from 3.5 to 2.5. Recipe C treated fabric shows half grade deterioration in the pilling grade from 3.5 to 3. As treatment D is considered it causes to reduce the pilling resistance. In terms of grades, it shows reduction in pilling grade from 3.5 to 3. Lastly, the treatment of the fabric with recipe E also causes to reduce piling grade from 3.5 to 2.5. To sum up, recipes B, C, D, and E showed a decrease in pilling resistance and pilling rating of the fabric. However, the results of the recipes C and D are comparatively appreciable which caused half grade deterioration in pilling as shown in Figure 2 and Table 4. On the other hand, recipes B and E caused the highest deterioration by one grade. The above results could be explained that during such treatments, the fraction between fabric and machines possibly caused to damage the surface fibers. Secondly, washing and finishing treatments caused increased wales and course density hence, yarns in the fabric come closer to each other. It causes to increase more protruding fiber per unit areas than untreated fibers, hence more pills appear per unit area [13]. Moreover, it is due to the ability of these softeners and finishes to reduce fiber to fiber friction by increasing individual fiber lubrication, thus, facilitating the fibers coming out of the main body of the fabric to form pills [13].

Effect of Finishes Treatments on Bursting Strength
Washing of fabric with recipe B cause to increase the bursting strength from 1.16 to 1.17 MPa. To improve the handfeel, of the fabric recipe, C was applied on the fabric and it has found that it causes to increase the bursting strength from 1.16 to 1.18 MPa.
To improve the hand-feel of the fabric, recipe D was applied to the fabric. The results reveal that the bursting strength increases from 1.16 to 1.19 MPa. To improve the wicking behavior of the fabric, recipe E was applied to the fabric. The results show an increase in bursting strength from 1.16 to 1.31 MPa as shown in Table 5. So, overall treatments B, C, D, and E showed 1.2%, 1.8%, 2.4%, and 4.2%

Effect of Finishes Treatments on Bursting Strength
Washing of fabric with recipe B cause to increase the bursting strength from 1.16 to 1.17 MPa. To improve the handfeel, of the fabric recipe, C was applied on the fabric and it has found that it causes to increase the bursting strength from 1.16 to 1.18 MPa.
To improve the hand-feel of the fabric, recipe D was applied to the fabric. The results reveal that the bursting strength increases from 1.16 to 1.19 MPa. To improve the wicking behavior of the fabric, recipe E was applied to the fabric. The results show an increase in bursting strength from 1.16 to 1.31 MPa as shown in Table 5. So, overall treatments B, C, D, and E showed 1.2%, 1.8%, 2.4%, and 4.2% increases in bursting strength, respectively. However, treatments D and E show more increase in bursting strength as compared to B and C as shown in Figures 3 and 4. Wet processing caused shrinkage and an increase in mass per unit area which has a direct relation to an increase in stitch density of the knitted fabric. Higher stitch density fabric required higher pressure to burst knitted fabric because a greater number of loops are prone to open and straightened before bursting [29]. Stiffer and brittle yarns can be easily broken then soft yarns and finishing treatments significantly reduce the stiffness of the yarns which leads to higher bursting strength of the fabric [30]. Moreover, softening treatment increased the smoothness of the yarn due to which yarn became more slippery when exposed to some force or pressure which caused an increase in bursting strength [16]. increases in bursting strength, respectively. However, treatments D and E show more increase in bursting strength as compared to B and C as shown in Figures 3 and 4. Wet processing caused shrinkage and an increase in mass per unit area which has a direct relation to an increase in stitch density of the knitted fabric. Higher stitch density fabric required higher pressure to burst knitted fabric because a greater number of loops are prone to open and straightened before bursting [29]. Stiffer and brittle yarns can be easily broken then soft yarns and finishing treatments significantly reduce the stiffness of the yarns which leads to higher bursting strength of the fabric [30]. Moreover, softening treatment increased the smoothness of the yarn due to which yarn became more slippery when exposed to some force or pressure which caused an increase in bursting strength [16].

Effect of Finishes Treatments on Wale-Wise and Course-Wise Vertical Wicking
Wicking test results for wale-wise fabric samples revealed that the treatment of fabric with recipe B shows an increase in wicking speed from 0.4 to 5 mm/min. Recipe C treatment shows an increase of wicking speed from 0.4 and 5.5 mm/min. When the fabric was treated with recipe D wicking rate decrease from 0.4 to 0.33 mm/min. Recipe E increase from 0.4 to 5.1 mm/min. Thus, overall, treatments B, C, and E showed 12.50, 8, and 13.75-time increases in wicking speed, respectively. However, treatment D shows five-times decrease. In all treatments, wicking speed showed a significant increase as shown in Figure 5. Treatment E showed the highest increase in wicking speed, treatment B showed a medium increase in wicking speed, while treatment C showed the least improvement in wicking speed. However, treatment D showed a slight decrease in the wicking rate. Because such finishes increased the hydrophilicity of the fabric except for silicon finishes which increase hydrophobicity. The hydrophilicity and hydrophobicity of the fabric directly affect the capillary action hence a significant increase has been observed in the vertical wicking rate by all treatment except treatment D (silicon wash) which reduce hydrophilicity and cause to deteriorate wicking rate [31].
Wicking test results for course-wise samples revealed that treatments B, C, and E show 10, 6.8, and 10.5 times increase in vertical wicking speed respectively. However, treatment D showed a 7.5-times decrease in the wicking rate. In all treatments, wicking speed showed a significant increase, except for treatment D, as shown in Figure 5 and Table 6. However, treatment E showed the highest increase in wicking speed. Treatment C showed the least improvement in wicking speed while treatment D showed a significant decrease. It has also been observed that the vertical wicking rate, of course, wise samples has been observed higher than that of the wale-wise samples because course density of the knitted fabric was mostly higher than wales density as shown in Table 1. Higher course density means lower distance amongst course-wise stitches which boost capillary action. On the other hand, lower wale density means more porosity and porosity prevent capillary action that is why the coursewise wicking rate is higher than the wale-wise wicking rate [32].

Effect of Finishes Treatments on Wale-Wise and Course-Wise Vertical Wicking
Wicking test results for wale-wise fabric samples revealed that the treatment of fabric with recipe B shows an increase in wicking speed from 0.4 to 5 mm/min. Recipe C treatment shows an increase of wicking speed from 0.4 and 5.5 mm/min. When the fabric was treated with recipe D wicking rate decrease from 0.4 to 0.33 mm/min. Recipe E increase from 0.4 to 5.1 mm/min. Thus, overall, treatments B, C, and E showed 12.50, 8, and 13.75-time increases in wicking speed, respectively. However, treatment D shows five-times decrease. In all treatments, wicking speed showed a significant increase as shown in Figure 5. Treatment E showed the highest increase in wicking speed, treatment B showed a medium increase in wicking speed, while treatment C showed the least improvement in wicking speed. However, treatment D showed a slight decrease in the wicking rate. Because such finishes increased the hydrophilicity of the fabric except for silicon finishes which increase hydrophobicity. The hydrophilicity and hydrophobicity of the fabric directly affect the capillary action hence a significant increase has been observed in the vertical wicking rate by all treatment except treatment D (silicon wash) which reduce hydrophilicity and cause to deteriorate wicking rate [31].
Wicking test results for course-wise samples revealed that treatments B, C, and E show 10, 6.8, and 10.5 times increase in vertical wicking speed respectively. However, treatment D showed a 7.5-times decrease in the wicking rate. In all treatments, wicking speed showed a significant increase, except for treatment D, as shown in Figure 5 and Table 6. However, treatment E showed the highest increase in wicking speed. Treatment C showed the least improvement in wicking speed while treatment D showed a significant decrease. It has also been observed that the vertical wicking rate, of course, wise samples has been observed higher than that of the wale-wise samples because course density of the knitted fabric was mostly higher than wales density as shown in Table 1. Higher course density means lower distance amongst course-wise stitches which boost capillary action. On the other hand, lower wale density means more porosity and porosity prevent capillary action that is why the course-wise wicking rate is higher than the wale-wise wicking rate [32].

Conclusions
This study revealed the effect of washing, silicon softeners, and wicking finishes on the mass per unit area, pilling behavior, bursting strength, and wicking behavior of the polyester weft-knitted jersey fabric. Results revealed that mass per unit area (GSM) of the fabric increases by all treatments. However, treatment E showed the highest increase of 8.5% and treatments B and C showed the lowest increase in GSM of up to 5%. Pilling showed deterioration by all treatments, however, treatments B and E showed the highest deterioration of 1 grade and C and D show the lowest deterioration by half a grade. Bursting strength of the fabric showed increases by all treatments, however, treatment E showed the highest increase of 4.2% and B showed the least increase of just 1.8%. Vertical Wicking of the fabric showed significant improvement by all finishes in both wale-wise and course-wise except for treatment D which showed a significant reduction in the wicking rate. Treatment E showed the highest increase in wicking rate 13.75 times in the wale-wise direction and 10.5 times in the coursewise direction as compared to the grey fabric while treatment C showed the lowest increase in wicking rate of 8 times in the wale-wise and 4 times in course-wise as compared to the grey fabric.

Conclusions
This study revealed the effect of washing, silicon softeners, and wicking finishes on the mass per unit area, pilling behavior, bursting strength, and wicking behavior of the polyester weft-knitted jersey fabric. Results revealed that mass per unit area (GSM) of the fabric increases by all treatments. However, treatment E showed the highest increase of 8.5% and treatments B and C showed the lowest increase in GSM of up to 5%. Pilling showed deterioration by all treatments, however, treatments B and E showed the highest deterioration of 1 grade and C and D show the lowest deterioration by half a grade. Bursting strength of the fabric showed increases by all treatments, however, treatment E showed the highest increase of 4.2% and B showed the least increase of just 1.8%. Vertical Wicking of the fabric showed significant improvement by all finishes in both wale-wise and course-wise except for treatment D which showed a significant reduction in the wicking rate. Treatment E showed the highest increase in wicking rate 13.75 times in the wale-wise direction and 10.5 times in the course-wise direction as compared to the grey fabric while treatment C showed the lowest increase in wicking rate of 8 times in the wale-wise and 4 times in course-wise as compared to the grey fabric.