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Effect of knitting tightness & ether based lubricating agent on 100% cotton knitted single jersey fabric crease mark property

Abstract

Single jersey cotton weft knitted fabrics tend to form Crease Mark. Crease Mark is an indicative quality problem which is undesirable for Customer. This Project analyzed the root cause analysis of the Crease mark. It   was found that knitting tightness has a relation to form Crease mark. The experiment showed that 7.36% Crease mark form in 200 GSM fabric produces from 20s yarn with 3.1 mm Stitch length, which is higher than the 4.60% Crease mark for 3.25 mm Stitch length.

On the other hand Improved the Crease mark by using Ether based Lubricating agent Persotex AFC. Experiment with Persotex AFC & Multifunctional agent persoclean STN showed that 3.55% & 1.31% crease mark occurred respectively 3.1 mm & 3.25 mm stitch length 200 GSM fabric. The Crease mark is minor so reduces the extra cost for reprocessing the fabric.

Keywords: Crease mark, Stitch length, Knitting Tightness, Tightness

Factor, Anticreasing Agent

  1. Introduction

Cotton is one of the most popular textile materials because of its superior wearing comfort, hygroscopicity, dyeability, and air permeability. Nevertheless, cotton fabrics readily form creases during chemical processing or home laundering. The poor crease property of cotton is mainly due to the lack of covalence between molecular chains, which develops crease marks against external stress due to the formation of new H-bonds.

The dimensional stability of a fibre depends on the arrangement of its structural elements and the forces bonding them. In the case of the cellulose chain, the individual glucose components are bonded covalently with each other via a glycosidic oxygen bridge. The bonding of cellulose chains with one another is made possible by van der Waal forces and by the development of hydrogen bridges.

The forces acting from outside in system deformation tend to break existing bonds. If the latter resist this influence, full recovery to the initial position occurs when the load is removed. Residual deformation (creases) stems from irreversible bond changes, resulting in the slipping of fibrils and molecules by Hydrogen Bridge fracture.

Of importance in the crease behavior of cellulose fibres is the degree of orientation, which describes the proportions of amorphous and crystalline zones. The creasing tendency rises as the polymer degree of orientation increases. There are several reasons for Crease mark, one of them:

  1. Fabric produced from High twisted yarn:

The twist is the spiral arrangement of the fibres around the axis of the yarn. The amount of twist inserted in a thread defines the appearance and the strength of the yarn. The number of twists is referred to as turns per inch.

Yarns for machine knitting are usually loosely twisted because softness is desired in knit fabrics. High twisted yarn will create its impression on the fabric feel and create a fabric defect known as spirality (due to unrelieved torque in yarn). And the fabric will harder and relaxation property is less; hence the fabric has a high tendency to form a crease.

  1. Knitting Tightness:

Tightness factor

Tightness factor indicates the relative tension of a plain-weft knitted structure. Fabric tightness is the relative looseness or tightness of knitted fabrics, so as it implies looseness and tightness of a knitted fabrics, the only things that can varies this is the loop length which is also known as stitch length. When the stitch length is big, so the structure of the fabrics is loosened and the fabrics become slack and when the loops are small, the fabric is tighter.

The formulae for calculating tightness factor are as follows

Tightness Factor = √ tex count ÷ Stitch length

When construction is tighter, the fabric is compact; hence. Cellulose bond-breaking tendency is high and the friction rate is high in dyeing machine, therefore, has an increased tendency to form crease mark.

  • Dyeing Process:
  1. Friction between fabric & roller (winch): During exhaust dyeing fabric is passed through the winch roller there occur friction with material to the metal roller. Where the bonding of cellulose tends to break down as a result form Crease Mark.
  2. Fabric weight: Fabric weight increased in wet state. This fabric is storing in a j-box of a dyeing machine in a layer by layer. In this state, the material under pressure decreases the Crease property of the fabric.
  3. Fabric tension in the winch machine: When reel speed is high, friction is more. That’s why crease form.

In this project we are going to find out the relation of knitting tightness on Crease Mark & effect on persotex AFC(lubricating agent) on crease Mark.

  1. Experimental (Methods & Materials)

2.1 Experiment for Effect of     knitting Tightness

2.1.1Materials:

Fabric: 100%    Cotton knitted single jersey, Yarn Count: 20s, GSM:200, Dia: 72inch, Machine Dia×gauge:32×24, Stitch length: respectively 3.10 &  3. 25mm.Supplier Mim Fashion Ltd.

ht: 450kg

Colour: 22-Phantom

2.1.2 Chemicals:

Table2.1: Pre-treatment (Scouring & Bleaching) Liquor ratio 1:8
SL Item Group Item Description Ratio
1 Detergent Chimistone NILFCone 0.8 g/l
2 Sequestering Invatex Cs 0.5g/l
3 Stabilizer CROSPREP SFCS 0.4g/l
4 Anti-Creasing Agent NEX Crease ACA (Conc) 0.015g/l
5 Alkali Caustic Soda 2.20g/l
6 Oxidizing agent Hydrogen peroxide 2.10g/l
7 Acid Puronal Ar Liq 1.0g/l
8 H2O2 Killer JQ-CAT1000 0.35g/l
9 Enzyme Cellulase 0.30 % on BW

 

Table 2.2: Dye Bath Chemical Liquor Ratio 1:8
SL Item Group Item Description Ratio
1 Levelling agent Croscolor SLR new 1.0g/l
2 Sequestering agent Kappacom E-12 1.5 g/l
3 Anticreasing Agent Nex Crease ACA(conc) 0.015 g/l
4 Electrolyte Glouber salt 65 g/l
5 Alkali Soda Ash Light 16 g/l
6 Acid Puronal Ar Liq 1.0 g/l
7 Soaping Agent Exoline 3027 0.9 g/l

2.1.3Machine:

Fongs High pressure & Temperature Dyeing Machine Capacity: 560kg

Cycle time: 3 minute, Reel speed: 250 m/min

2.1.4 Procedure:

2.1.4.1 Pretreatment

Load the fabric into the machine & dosing the chemical & Auxiliaries. Temperature up at 950C and Run the process for 50 minutes. After completing scouring drain out the liquor from the dye bath. Rinse with hot at 900 C 10 minute. Neutralize the fabric with acid treatment and rinse twice at normal temperature & carry out next process.Fig:2.1

2.1.4.2 Dyeing:

Filling the water & Run 5-6 min at 600C, Check Ph 6, dosing the Auxiliaries then run 6 min, dosing color linearly 30 min & run for 20 min. Then dosing ½ salt and run 6 minutes, again dosing another ½ salt and run 20 minutes. Now dosing soda 70% progressive for 50 minutes and run 10 minutes, and then check the sample’s shade. Fig: 2.2

2.1.4.3 After Treatment:

After completing dyeing, process for wash the dyed fabric. Rinse twice for 10 minute, Normal hot at 600C for 6 minute then drain the water, Run wash for 6 minute, Neutralize the fabric by acid at 500 C for 15 minute and drain the liquor, then Soaping and softener at 900C for 20 minute then drain the liquor, hot rinse twice at 800 for 10 minute, then cold rinse 2 times & drain the water then unload the fabric. Fig2.3.

2.1.5 Finishing process

The finishing process designated slitting & dewatering on Blanco m/c, and then Stentering was done.

2.2 Experiment with Persotex AFC

2.2.1 Materials:

Fabric: 100% Cotton knitted single jersey, Yarn Count: 20s, GSM:200, Dia: 72inch, Machine Dia×gauge:32×24, Stitch length: respectively 3.10 & 3. 25mm.Supplier Mim Fashion Ltd.

Weight: 479kg

Colour: 36-Black

Pretreatment-Scouring
Figure 2.1: Pretreatment (Scouring).
Dyeing-process
Figure 2.2: Dyeing process.
After-Treatment-process
Figure 2.3: After Treatment process.

2.2.2 Chemicals:

Lubricating Agent (Persotex AFC) From Taiwan Persotex.

Persotex AFC is a special anionic surfactant which has excellent softening, lubricity and also has good resistance to alkali and salt. It can prevent the development of cracks and crease marks when dyeing of cellulose fibers & their blends.

Persoclean STN (Emulsifier and Scouring Agent) from Taiwan Persotex.

Persoclean STN 1g/l, Persotex AFC 1.5g/l, sequestering agent 0.5g/l, Enzyme 0.30% on BW used for Pre- Treatment. Liquor Ratio: 1:7

Table 2.3: Dye Bath Chemical, Liquor Ratio 1:7
SL Item Group Item Description Ratio
1 Levelling Agent Croscolor SLR new 1.0g/l
2 Sequestering agent Kappacom E-12 1.50g/l
3 Anti-Creasing Agent Persotex AFC 1.5 g/l
4 Electrolyte Glouber salt 80 g/l
5 Alkali Soda Ash Light 5 g/l
6 Alkali Caustic soda 1.5g/l
7 Acid Puronal AR Liq 1.0 g/l
8 Soaping Agent Exoline 3027 1.0g/l

2.2.3 Machine:

Fongs High pressure & Temperature Dyeing Machine

Origin: China, Capacity: 560kg.

Parameter for Machine:

Cycle Time: 105 Second (Must be less than 2 min)

Reel Speed: 200 m/min

Pump Speed: 95%

2.2.4 Procedure:

2.2.4.1 Pretreatment:

Pretreatment-process
Figure 2.4: Pretreatment process.

Load the fabric into the machine & Dosing the chemical & Auxiliaries Persotex AFC, Persoclean STN & Sequestering agent. Temperature up at 650C and

Run the process for 40 minutes. After completing scouring drain out the liquor from the dye bath. Hot rinse at 800 C for 8 minute then drain the liquor. Fig: 2.4

Auxiliaries-dyeing-process
Figure 2.5: dyeing process.

2.2.4.2 Dyeing:

Filling the water at 550C, Check Ph 6, dosing the Auxiliaries then run 6 min, Full salt dosing then run for 20 minute, dosing color linearly 30 min & run for 20 min. Soda 2 g/l dosing for 20 minute & run 10 minute. Then temperature up at 600C .Now dosing soda 3g/l & 1.5g/l caustic 70% progressive for 50 minutes and run 10 minutes then check shade of the sample. Fig: 2.5

2.2.4.3 After Treatment:

After completing dyeing, process for wash the dyed fabric. Rinse twice for 10 minute, Normal hot at 600C for 6 minute then drain the water, Run wash for 6 minute, Neutralize the fabric by acid at 500 C for 15 minute and drain the liquor, then Soaping and softener at 900C for 20 minute then drain the liquor, then cold rinse 2 times & drain the water then unload the fabric. Fig: 2.6

After Pretreatment process
Figure 2.6: After Pretreatment process.

2.2.5 Finishing process

The finishing process designated slitting & dewatering on Blanco m/c, and then Stentering was done.

  1. Test methods:

Crease mark checked visually by Quality expert.

Shrinkage test determined by Dimensional Stability of Washing (ISO 6330: 2012) & Spirality determine by ISO 16322-2.

Shrinkage% = x 100

Spirality calculation:

S=

Spirality = , where,S1 = right side distance of the specimen from the stitch line wash, S2 =  Left side distance of the specimen from the stitch line wash, L= Length before wash.

  1. Results:

4.1. Crease mark Check in for Experiment 2.1

Table 4.1: Data of Crease mark 
Stitch Length Checked fabric length Size of Fault No. Of fault Crease Mark %
3.1 mm 190 m 3.0״-6.0״ 14 7.36%
3.25 mm 193m 3.0״-6.0״ 9 4.60%

Calculation:

Number of Fault in 190-meter fabric is 14

So the no. of fault in 100 meter fabric is = (14 x100)/190 = 7.36%

The rest fault percentage is calculated in the same way.

Shrinkage:

For Stitch length 3.1 mm: Length % = -6%

Width% = -4.8%

For Stitch length 3.25 mm: Length % = -2.7%

Width %= -4.3%

Spirality:

For Stitch length 3.1 mm: 1%

For Stitch length 3.25 mm: 0.5%

 

4.2. Crease mark Check in Experiment 2.2

Table 4.2: Crease mark Check
Stitch Length Checked fabric length Size of Fault No. Of fault Crease Mark %
3.1 mm 197m 3.0״-6.0״ 7 3.55%
3.25 mm 381m 3.0״-6.0״ 5 1.31%

 

Stitch Length Checked fabric length Size of Fault No. Of fault Crease Mark %
3.1 mm 197m 3.0״-6.0״ 7 3.55%
3.25 mm 381m 3.0״-6.0״ 5 1.31%

 Shrinkage:

For Stitch length 3.1 mm: Length % = -6%

Width% = -4.8%

For Stitch length 3.25 mm: Length % = -2.7%

Width %= -4.3%

Spirality:

For Stitch length 3.1 mm: 1%

For Stitch length 3.25 mm: 0.5%

  1. Discussion:

From the result of Experiment 2.1, it was found 7.36% & 4.60% Crease Mark found for stitch length respectively 3.10 & 3.25 mm, Where GSM of Those fabric 200 and Yarn Count 20s. And in experiment 2.2 there was 3.55% & 1.31% crease mark found for respectively 3.10 & 3.25 mm stitch length after dyeing with Persotex AFC.

In experiment 2.1 indicates that there is a relation of Crease Mark on fabric construction. Higher the stitch length lower the crease mark & lower stitch length higher the crease Mark. In Table no: 5.1. It also Showed that Shrinkage rate for stitch length 3.1 mm is – 6% for length wise & -4.8% for width wise, and for 3.25 mm stitch length -2.7% in length wise & – 4.3% in width wise.

Crease Mark Relation on Stitch length
Figure 2.7: Crease Mark Relation on Stitch Length Exp2.1.
  1. Conclusion:

This project work presents an experimental investigation effect of knitting tightness & Ether based lubricating agent on 100% cotton knitted single jersey fabric Crease Mark property. We have gained the relation of stich length on Crease mark for specific GSM and count of yarn & improve crease mark by using persotex AFC.

Crease mark is a common quality problem in textile industry for this problem factory needs extra process & time so cost increases for this fault. We hope this work taken by us can play a significant role in future practical life to improve quality problem in a textile industry.

Crease Mark Relation on Stitch
Figure 2.8: Crease Mark Relation on Stitch Length Exp2.
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