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10 Problems Faced by Knit Manufacturers Today

April 05, 2018 Rohit Abhishek
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In recent times, we have seen a surge in demands of knit clothing throughout the world. In 2017, the entire knits trade amounted to 185 billion USD, amounting to around 50% of all material types. This trend is only going to go up. There are several factors favoring knits industry:
  1. The investment needed to set a knitting industry is quite lesser than any fabric making unit
  2. The lead time for manufacturing knit garments is lesser than that of woven fabrics
  3. There is a good flexibility in knitting process, allowing a rapid change in style and design. This allows a quick changeover which is much relevant in today's fast-changing fashion
Due to fast moving trends and growing media awareness, the current market demands have led to huge competition between the brands offering best bargain and promotional discounts to consumers. All this fierce competition has made manufacturers to offer multiple products at throwaway prices, limiting the operational profits.
 
Though the knit manufacturing offers various benefits to manufacturers, it comes with its own list of difficulties.
 

Problem 1: Weight to Length Conversion

The biggest problem faced by knitting facilities throughout the world is the absence of proper length measuring apparatus.

This is a much bigger problem in vertical setup facilities producing knitted textiles where there is a lack of investment on such length measuring apparatus. Also, the short lead time refrains manufacturers from following to this process. The importance is given to productivity with fewer resources. As such, devoting extra resources to length measurement means more manpower and space allotment. In such units, the problem is tackled by resorting to using weight as the system of measurement.

The weight of a fabric roll is measured on a weighing machine as it takes much less time than measuring length.  The weight is used everywhere from purchase till issuing of the roll.

Now, when the fabric is needed for cutting, the weight needs to be converted to length for proper tracking. This is done using the formula:

Now, this seems easy. Except that the parameters here are not so constant.

Let us have a look at the different parameters which comes into play over here.

1.      Weight in kilograms: The weight parameter almost remains constant. Though the weighing must be done properly without any interference in the process. Any problem here will ruin the complete thing. In almost all facilities, this process is recorded without any issue.

2.      GSM: This is the most uncertain parameter. Because of the knitting process, the composition is susceptible to huge variation at different points in the same roll. This can never give a proper GSM value as it can change if taken at a different part of the roll. Normally, it is taken at three points, i.e., start, middle, and end of the roll. Now, the procedure to take this is cutting out the fabric from the above points. A gsm machine is available, which cuts out a template in the shape of a circular fabric with the diameter of 113 mm. The sample cut out is almost with an area of 100 cm2. The cut sample is weighed and is multiplied by 100 to get the gsm value of the roll. 

 

As the gsm can vary at various points throughout the fabric, it does not give a clear-cut value. This amounts to discrepancies in the length of the roll, which in case of a larger sample, amounts to huge excess or shortage in the rolls.

3.     Width in meters: This is the parameter susceptible to different values inside the same roll. Though the width changes have remained a regular feature in the problem book of the cutting floor, it impacts the calculation to a much bigger extent. The increase/decrease in roll-width on floor generally forces changes in the marker width, stopping the laying process to remake markers. This hamper production. But, what is ignored is the fact that the actual length also changes with the change in width. This also is one of the parameters which creates discrepancies in roll length.


What is the solution?

The solution, in this case, can only be the elimination of this process completely. It has already been done in most countries. Still, the process is still prevalent in some countries of the Indian subcontinent. The length measuring facilities can provide a freedom from all these discrepancies and a good control on the most important cost controlling part, fabric rolls.

Problem 2: Relaxation

The knitting and packing of the knitted rolls are done at a great tension on the fabric. Due to the strain experienced by the rolls in such cases, the fabric elongates. If the fabric is laid and cut in this state, the cut pieces are susceptible to shrinkage at the time of assembly and can thus destroy the whole piece.

To avoid this, the process of relaxation is put into use. Before cutting, a relaxation period is finalized for different kinds of fabric. This period can be as low as 2 hours in some cases to as high as 48 hours. In this process, the rolls are opened and kept in bale form on a platter to allow them to relax and come back to their original length. This practice is common in almost all knit manufacturing facilities.

Now, where is the problem in all this?

The process of relaxation comes under question here. If the opened rolls are kept on top of each other, the roll weight on top greatly reduces the freedom of the fabric to relax. This form of stacking defeats the entire purpose of the relaxation.

When the knit fabric is relaxed, the length of the fabric changes along with the width. The relaxed fabric is worked upon with the width and length taken before relaxation. The result is the discrepancies in these fields. This is evident on the cutting floor when numerous marker changes happen due to a difference between marker width and fabric width. This causes a huge loss in production time. The reconciliation of the fabric is also affected but ignored citing the knits problems.

This practice is so abundant that in some factories they keep a huge buffer between the actual width of the fabric and the marker width. It can range from 4 inches to 8 inches. The loss of this fabric is ignored to compensate production time loss. In some facilities, they make markers on 3 widths:

·         the actual fabric width,

·         2 inches less than the actual width, and the

·         2 inches more than actual width.

 

What is the solution?

An ingenious way to handle this problem is to take the fabric width after relaxation. The width taken after relaxation will ensure there is no extra work in either marker making or any production losses. Also, the same will result in avoiding discrepancies in reconciliation.

intelloCut can come to our help in this scenario. intelloCut takes entry of the roll details, such as width, shrinkage, and shade. Based on the factory’s need, the grouping based on width, shade and shrinkage can be done. The grouping of the rolls and marker happens automatically in the system as per the above requirements. This step largely takes away all the manual calculations out of the work and saves much needed time on the floor. Also, this module considers the fabric availability and allocates markers as per the available fabric on the floor.

 

Problem 3: Curling/Edge allowance

In single jersey fabric, it is seen that the ends at the side of the roll curls away, thus rendering that portion unusable for laying, cutting and sewing. This behavior is due to the unbalanced loop structure and yarn/count of the fabric. This problem forces the cutting room to give unusual side allowance to avoid cutting the curled edges. A huge portion of the fabric is thus wasted and remains an unutilized burden on the cutting floor. As the buying width does not take curling allowance, the marker consumption on production markers increases, ending up with a short shipment.

There have been several kinds of research on the curling behavior but none of them has given any practical solution so far. Several procedures such as steaming the ends have been tried but if not done properly, can destroy the fabric.

What is the solution?

As of now, there has been no practical method to stop curling at fabric level.

 

Problem 4: Irregular Width Changes in a roll

When the knitted roll arrives at the fabric warehouse, it is a common practice to check only 10% of the rolls to make markers. In many cases, the roll shows different width when taken at different points in the same roll. Now, 90% roll width is not known or is taken only at the head of the roll. This creates a problem when there is a significant width change in the roll. This problem is more common in knits as the knit fabric is knitted in the circular form and then cut. The width irregularity can come either due to problems in knitting or due to cutting. This small discrepancy from manufacturing can lead to many significant problems later:

  1. Numerous marker changes on cutting floor, leading to production time losses.
  2. Numerous roll changes to utilize the existing markers, which also results in time losses.
  3. Fabric loss, if bigger width and smaller width rolls are cut together on smaller width.
  4. Improper tracking of the on-floor process losses.

 

What is the solution?

Although these problems can only be rectified and corrected at knitting stage by following a stringent check process, the losses can also be reduced by cutting floor. If 100% roll width inspection is followed and segregated before cutting, the fabric losses and production time losses can be controlled to a large extent.

This problem can be also be reduced, to an extent, if fabric grouping module of intelloCut is used. It automatically groups the rolls based on the different width and thus, reduces the losses on floor automatically by providing the marker width based on the available fabric width.

 

Problem 5: Shade Variations in a roll

Normally, the fabric is knitted as greige fabric and is later dyed to get the desired color. This process is very efficient as the process of knitting is fast due to no yarn change. Whatever color is required in the fabric, it is dyed in the dyeing unit.

Now, this has a problem. Because the fabric is quite long, the dyeing is done in a part by part manner. This means that there might be shade variation in those parts as keeping the shading formula same throughout, is a tough task. When such a condition arrives, the different shades must be handled differently to avoid shade variation after sewing. In such cases, special care is taken to not lay a ply with two different shades.

Also, sometimes, the dye is not done evenly in a widthwise form. This leads to shade variation from one selvedge to center of the roll. This can be a cumbersome situation for cutting floor. This phenomenon is normally known as CSV (Center to Selvedge Variation) defect.

 

What is the solution?

There can be two solutions to this:

  • If the CSV defect is too huge, the roll must be discarded.
  • But if the CSV defect is not so huge, a special marker can be made with pattern pieces of a size, placed along the length of the roll.

 

Problem 6:  Damage in fabric rolls

Damage in knits is a major problem. It is seen that the knit fabric has more cases of damages than woven fabric. This not only creates a problem in the operations but also decreases the utilization % of the fabric, forcing organizations to keep an extra buffer for damages. This increases the overall fabric cost, which in turn increases the final product cost.

There can be several reasons for damages in a fabric.

  1. Damages occurred during knitting: During knitting, sometimes due to mismanagement of the machines, the needle malfunction can cause miss-knits in the fabric. When found in repetitive fashion, this problem can create a havoc on the cutting floor, resulting in a generation of too many end bits to handle.
  2. Damages occurred during dyeing: Sometimes, a certain part of the fabric is dyed multiple times due to improper care during the dyeing process. These parts cannot be used anywhere and are thus marked as a damage.
  3. Damages occurred due to inspection cuts: Before laying, a template is taken out from fabric to perform various inspections such as GSM, shade and shrinkage testing. When the process is not controlled, the template cutout is more than what is required and taken out at different lengths. These cutouts, if smaller, are dealt with during panel replacement. If, however, the pieces are big enough, the whole portion is cut and taken out. This results in the generation of numerous end bits again.
  4. Damages occurred due to manual handling: During laying and cutting, when the fabric is not handled carefully, the fabric gets caught up in machinery and cut. In these scenarios, the damaged fabric is to be taken out completely.

 

What is the solution? 

  • A proper management and care of the machinery can deal with these damages at various levels.
  • A proper inspection and maintenance of the machinery are needed to ensure their flawless operations and their longevity.
  • Different amount of care is to be taken based on the different kinds of gsm fabrics. We cannot treat all fabric in a similar manner
  • Time to time workshop is needed in the various facilities to ensure proper management of fabrics.
  • The inspection process should be standardized so that a single template is taken for different inspections. The template cutting should be done at a single place with proper controls and proper templates.

 Also, the extent of the problem is aggravated by inadequate tracking of these damages. This information is nowhere in the books and thus the extent of the problem is unknown to upper management. Result: No action is taken to improve this. The first requirement over here is the tracking of each of the damages. Also, these damage entries should be reflected in the reports submitted to upper management. Only after this is done, any course of action can be planned to tackle it.

intelloCut’s on-floor tracking is developed to handle this requirement in the most efficient manner. intelloCut tracks on-floor changes in the system and suggest the most optimal revised plan for the floor. The plan adjusts to the real scenario on-floor in a similar manner as the GPS guided navigation. Also, the status of the plan is tracked regularly. The software alerts the user in case the current plan is generating end bits, which if unused, will be wasted. The user can take a decision to use the end bits in part change or change the plan. This intelligence will, unquestionably, result in the reduction in wastages and lead to accurate tracking.

 

Problem 7:  Shrinkage Variations

Shrinkage is the property of reduction/increase in the length and/or width of the fabric after wash. This is one of the most common facts of fabric quality. The amount of fabric that will shrink is not predictable as fabric shrinkage varies from one type of fabric to another. Even roll to roll shrinkage variation is found in the same fabric and in the same order (due to lot variation).

The styles which need washing post the assembly must determine shrinkage values of the fabric rolls. Rolls with considerable shrinkage difference cannot be mixed and cut together. If cut together, it will result in pieces responding differently to wash program. There is a risk of spec variation (out of measurement tolerance). The measurement of shrinkage is done in the following two methods.

  1. In Fabric Swatch: 100 X 100 cm fabric swatch is cut and marked length and width wise. The fabric is washed and post wash, length and width variation is checked to find fabric shrinkage percentage.
     
  2. In Blanket Form: Instead of fabric sample, a blanket is made with the fabric (3 sides closed and one side open through stitching to also record shrinkage behavior inseams). The blanket is washed in washing machine and shrinkage percentages are recorded.

 

What is the solution?

There are two ways to handle shrinkage variation during the cutting process.

  1. Adding shrinkage allowance to the pattern pieces while making markers: In this step, the pattern pieces include shrinkage allowance such that after cutting and washing, the garment shrinks to the size as per tech specifications.
  2. Using Cut Panel Laundry (CPL): In this step, the fabric is laid, cut and washed first. After washing, the fabric shrinks and comes back to its actual state. The pattern is then cut out of this fabric without any allowance and garment is constructed on normal specifications.    

 

Advantages of CPL over adding shrinkage allowances on the marker

  • CPL process fabric is completely preshrunk and no need to change the base pattern prior to bulk cutting

Disadvantages of CPL over adding shrinkage allowances on the marker

  • Huge unutilized fabric ends, results in heavy uncontrolled fabric losses
  • Double laying time
  • Huge extra effort in the processing of fabric before and after wash
  • No proper tracking of the fabric

 

 Problem 8: Uncontrolled Splicing

Splicing is a process where the fabric is overlapped at certain points in a lay to start laying ply from where the previous roll has ended. It helps in reducing the generation of end bits. By doing this, the need of making small markers is greatly reduced. In respect to the cutting floor, this process is a win-win case as it reduces the extra work of utilizing small end bits in small markers.

 

Then, why is this a problem?

This is a problem because, in this process, the splicing overlap is not captured. This results in huge hidden wastages as cutting person go for all the overlap regardless of their length. The worry is that the fabric which goes inside overlap is hidden and cannot be used anywhere else. As it is normally done on the floor manually, the accuracy of this process raises a lot of questions. If there are 20 overlaps in a lay with each overlap at 20 inches, 400 inches or 11 yards of fabric goes straightaway to wastages. As it is not tracked on the floor, the extent of the wastages is unknown.

What is the solution?

intelloCut handles this problem very efficiently by enabling the splicing report from CAD software. The overlap length is controlled and printed on a marker. Also, as the splicing is tracked automatically in intelloCut, the tracking is open. Splicing reduces the number of end bits but not eliminates it. If the extra end bit is not taken out, the overlap wastages surge ahead. intelloCut processes ensure that the splicing is controlled and the markers are revised as per the on-floor live scenarios. It revises the plan as per the end bits generated on the floor.

 

Problem 9: Improper Remnant Planning

The generation of end bits while cutting of any fabric is inevitable. The damages and shade variations act as the multiplier in end bits generation. The end bits, thus generated need to be tracked continuously and utilized properly using end bit marker planning. The short lead time and hand to mouth situation of fabric receipt leave very less scope of remnant planning. This can result in over 5-10% of fabric getting wasted on the floor and are untraceable. The units end up buying more than what is required to handle this case. This ends up increasing cost in already squeezed out costing. 

What is the solution?

In the above cases, what is needed is a solution which tracks on-floor end bits and plans them automatically in the existing plan with the smallest modification. This has to be automatic and free from manual intervention to provide better control over processes and ultimately the cost.

intelloCut fits exactly in this gap, providing the much-needed relief to the operators as well as the planning personnel. The live tracking and modification in the plan as per floor scenario enables the floor to cut down on end bits going in wastage. Not only this, the transparency provided is pretty helpful in reducing the fabric ordering in later stages.