Monday, 1 October 2012

Fabric Losses during Spreading

The percentages of various costs that add up to the garment cost are as follows:

1.Raw Material cost: 50%
2.Direct labour Cost: 20%
3.Indirect Labour charges and factory overheads: 30%

The raw material cost ranges from 40% for hosiery to 60% for lingerie. The cost of fabrics is 80% of the cost of raw material. 

The fabrics can be broadly divided into the following three categories:
1. Tubular Knitted Fabric
2. Narrow open width fabric: The fabric width can accommodate two body pieces. Maximum market efficiency can be achieved if the number of smaller pattern pieces in the garment are relatively more. 
3. Wide open width fabric: This type of fabric is having a width of 1.5 meters and three body pieces can be placed in the width of the fabric. 

Fabric Losses
During the cutting process two types of fabric losses occur:
1. Marking Loss
2. Spreading Loss

Marking Loss arises due to the gap and the nonuseable areas at places between the pattern pieces of a marker. Marker efficiency indicates the amount of marking loss. 

Spreading loss is the fabric loss outside the marker. The various fabrics outside the marker are classified into different groups:

1. End of Ply Loss
2. End of Piece Losses
3. Edge Losses
4. Splicing Losses 
5. Remnant Losses
6. Ticket length Losses

1. End of Ply loss: The flexibility, limpness, extensibility alongwith the limitation of the spreading machinery necessitates an allowance of some fabric at the end of each ply. These losses may be upto 2 cm at each end or 4 cm per ply.

The end of ply loss is 1-2% of the total fabric usage. 

2.  End of Piece(Thaan) Losses: In textile industry, fabrics are produced and processed in different batches. This makes the fabric ends unsitable for use due to marks or distortions created.  

The end of piece varies from 0.5-1% of the total fabric usage. 

The loss is minimized if the average length of pieces that are purchased is increased. 

3. Edge Losses:  In normal practice during marker planning, the width of the marker is kept a few centimeters less than the edge-to-edge width of the fabric. The marker is made according to the usable width of the fabric. The usable fabric width depends upon the quality of the selvedge, the consistency of fabric width, and also on the precision of edge control during spreading. Let the fabric edge-to-edge width is 100 cm, and the marker width is 3 cm less than the fabric width. The edge loss is 3%. If the fabric edge-to-edge width is 150 cm, the loss is 2%.

Thus wider width has other benefits besides improved marker efficiency. 

4. Splicing Losses: Splicing is the process of overlapping cut ends ( the end of one length of the fabric and the beginning of the other) of two separate pieces of the fabrics so that the spreading is continuous.  Splicing is necessary as one roll of fabric is finished and the next taken into use. 
Also during spreading there may be some objectionable fabric faults, which make the product unsalable or substandard. These fausts are removed by cutting the lay at the fault point and incorporating splicing position into marker plans. 

During splicing the splicing line should be so selected that none of the pattern pieces contains the fault is incomplete. 

The position of the splice lines also dependent on the quality of the fabric being spread. If cutting out faulty material at the lay is a regular requirement, it is vital that the markers are provided with clearly defined splice lines. 

The splicing losses may vary up to the 5% of the total fabric usage. 

5. Remnant Losses: Remnant lengths are produced whenever companies separate different shades of fabric pieces and lay up only complete plies. 
Remnants are also generated when short lengths of material are left over after the completion of the lay, and are returned to the stores. 
All remnants are put to one side and cut separately. 

6. Length Losses ( L Losses): Woven fabrics and some knitted fabrics are sold by length.  Each fabrics piece is measured by the fabric supplier and a ticket is attached to each piece indicating the length for which the customer is invoiced. In many cases the gross length and the net length are marked in the ticket. This loss can be reduced by inspecting the length of the incoming fabric and reporting the fabric supplier in case of yardage short. 

What is FPT ( Fabric Package/Performance Test) and GPT ( Garment Package/Performance Test)

GPT- Garment Package/Performance Test

This test is done to analyze the performance of a garment after washing by the customer as per the wash care label.

We need three identical garments to perform this test:
1.       One Garment- Dimensional Stability
2.       One Garment – Appearance
3.       One Garment – Seam Slippage and Strength
4.       Button Pull Test- A Mock Patti is needed with about ten buttons attached to it.

Dimensional Stability is observed after washing.

Under appearance, visual observations are made regarding any changes in the fabric after washing. Defects like puckering, pilling, free movement of zipper.
Seam Slippage and Strength Test is done for all the seams present in the garment.

The aim is to find if the finished product is identical to the unfinished product.

Various buyers have their different requirements for GPT.

GPT is done after one wash or after three washes. Generally for Indian domestic suppliers or US buyers, GPT is done after three washes. For European buyers, GPT is done after one wash.

FPT- Fabric Package/Performance Test

Under FPT, about 3 meters fabric is required, the following tests are conducted:
1.       Yarn Count
2.       Construction
3.       GSM
4.       Fiber Composition
5.       Tensile Strength
6.       Tear Strength
7.       Colorfastness to washing at 40 deg.
8.       Colorfastness to rubbing.
9.       Colorfastness to perspiration.
10.   Colorfastness to Water.
11.   Shrinkage.

Here is an FPT from a company. 

Basically it contains the color properties and physical properties of the fabric. 

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