Relation between Stitch Lengths, Yarn Count, GSM & Machine Dia

Stitch length:

Stitch length (knitting) is the length of yarn in a knitted loop. Stitch length is theoretically a single length of yarn which includes one needle loop half the length of yarn (half of a sinker loop) between that needle loop and the adjacent needle loops on either side of it.

Yarn count:
Yarn count is the numerical expression which indicates or expressed the fineness or coarseness of yarn. According to Textile Institute, Count a number indicating the mass per unit length or the length per unit mass of yarn. 

GSM:

‘GSM’ means ‘Gram per square meter’ that is the weight of fabric in gram per one square meter. By this we can compare the fabrics in unit area which is heavier and which is lighter. The GSM of fabric is one kind of specification of fabric which is very important for a textile engineer for understanding and production of fabric. 

1. Relation between Yarn count & GSM. 

For Single jersey, Count=4350/GSM and 

Ne=50.22-0.141GSM (For single Jersey) 

Ne=54.57-0.123GSM (For 1x1 Rib) 

Ne=59.12-0.119 GSM (For Lycra 1x1 Rib)

2. Relation between GSM, Stitch Length and Yarn Count. 

                                 K 
GSM = …………………………………….                    k=constant 
             Yarn count (Ne) X Stitch length 

K=12068.59 (Single jersey or plain) 

K=16431.497 (1x1 Rib) 

K=19005.333 (2x1 Rib) 

3. Relation between Fabric Dia & machine Diameter. 
Fabric Dia = (Machine Dia X 2) ± 5% for single jersey 
Fabric Dia = (Machine Dia X 4/3) ±5% For Rib.

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Fabric Faults | Causes of Woven Fabrics Defects or Faults

Fabric Faults

Fabric faults are responsible for major defects found by the garment industry. Due to the increasing demand for quality fabrics, high quality requirements are today greater since customer has become more aware of “Non-quality” problems. In order to avoid fabric rejection, mills have to produce fabrics of high quality, constantly. Often inspectors are given the responsibility of inspecting finished garments without adequate training in fabric defects and their causes. The ultimate solution, of course, is to provide actual examples or photographs of both major and minor defects.

Woven fabric

Names of Woven Fabrics Defects or Faults: 

1. Bad Selvedge
2. Burl Mark
3. Drawbacks
4. Dropped Pick
5. End Out
6. Jerk-in
7. Knots
8. Mixed End (Yarn)
9. Mixed Filling
10. Open Reed
11. Slub
12. Smash
13. Soiled Filling or End
14. Stop Mark
15. Thin Place 
16. Holes 
17. Drop Stitches
18. Loop Distortion

1. Bad Selvedge
Causes: A defect in a fabric because of faulty weaving, warp ends being set too far apart for the thickness of the yarn or in finished fabric, an appearance in which the underlying structures is not connected to the degree required. 

2. Burl Mark
Causes: When a slub or extra piece of yarn is woven into the fabric, it is often removed by a "burling tool." This will usually leave an open place in the fabric. 

3. Drawbacks 
Causes: Caused by excessive loom tension gradually applied by some abnormal restriction. When the restriction is removed the excess slack is woven into the fabric. Usually the ends are broken. 

4. Dropped Pick 
Causes: Caused by the filling insertion mechanism on a shuttleless loom not holding the filling yarn, causing the filling yarn to be woven without tension. The filling yarn appears as "kinky." There will also be areas of "end out." 

5. End Out 
Causes: Caused by yarn breaking and loom continuing to run with missing end. 

6. Jerk-in 
Causes: Caused by an extra piece of filling yarn being jerked part way into the fabric by the shuttle. The defect will appear at the selvage. 

7. Knots 
Causes: Caused by tying spools of yarn together. 

8. Mixed End (Yarn) 
Causes: Yarn of a different fiber blend used on the wrap frame, resulting in a streak in the fabric. 

9. Mixed Filling 
Causes: Caused by bobbin of lightweight yarn or different fiber blend used in filling. Will appear as a distinct shade change. 

10. Open Reed 
Causes: Results from a bent reed wire causing wrap ends to be held apart, exposing the filling yarn. Will be conspicuous on fabrics that use different colored yarns on wrap and shuttle. 

11. Slub 
Causes: Usually caused by an extra piece of yarn that is woven into fabric. It can also be caused by thick places in the yarn. Often is caused by fly waste being spun in yarn in the spinning process. 

12. Smash 
Causes: Caused by a number of ruptured wrap ends that have been repaired. 

13. Soiled Filling or End 
Causes: Dirty, oil looking spots on the wrap or filling yarns, or on package-dyed yarn. 

14. Stop Mark 
Causes: When the loom is stopped, the yarn elongates under tension; when loom starts again' the slackness is woven into the fabric. 

15. Thin Place 
Causes: Often caused by the filling yarn breaking and the loom continuing to run until the operator notices the problem. 

 

16. Holes
Causes: Bad needle, take down mechanism too tight, high tension on yarn, bad yarn needle too tight in their slots, dial height too low or too high, badly tied knots, improper stitch setting.

17. Drop Stitches
Causes: Takedown mechanism too loose, defective needles, too loose yarn tension not sufficient, wrong needle timing set, needle tricks closed.

18. Loop Distortion
Causes: Bad and bent needles, bent trick walls, uneven yarn tension, needle timing set wrong, yarn carriers set wrong. 
   

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Garment Checking | Checking List of Apparel Garments Industry

Before packaging of garments must be check out. It is so much important before buying whatever thegarment is made by exporter or other foreign countries. 

Checking List of Garments Industry are Point out Below:

A. Cutting Quality Check List: 

1. Pattern to Cutting Garments Measurement Check.
2. Fabric diameter Measurement Check.
3. Cutting Lay Check.
4. Fabric Roll to Roll Shade Check.
5. Fabric G.S.M Check.
6. Bundle Mistake Check.
7. Size Mistake Check.
8. Fabric Color Mistake Check.
9. Yarn contaminated Check.
10. Any Fabric Problem Check.

B. Sewing Line quality Check List: 

1. Buyer Approved Sample & Measurement Sheet Check.
2. Sample Wise Input Check.
3. Buyer Approved Trims Card Check.
4. Buyer Approved Sample Wise Style Check.
5. All Machine Thread Tension Check.
6. Style Wise Print & Embroidery Placement Check.
7. All Process Measurement Check.
8. All Machine Oil Spot Check.
9. All Process S.P.I Check as Per Buyer Requirement.
10. Input Time Shading, Bundle Mistake & Size Mistake Check.
11. Buyer Approved Wise Contrast Color Check.
12. As per Buyer Requirement Wise Styling Check.
13. All Machine Stitch Tension Balance Properly.

C. Sewing Table Quality Check List: 

1. Style Wise Garments Check.
2. All Process Measurement Check..
3. Front Part, Back Part, Sleeve & Thread Shading Check.
4. S.P.I Check for All Process.
5. Print/Embroidery Placement Check.
6. Main Label, Care Label, Size Label &Care Symbol Check.
7. Size Mistake Check.
8. All Process Alter Check.
9. Any Fabric Fault /Rejection Check.

D. Finishing Quality Check List: 

1. As Per Buyer Requirement Wise Iron Check..
2. Buyer Approved Sample Wise Style Check.
3. Front Part, Back part, Sleeve, Rib Thread & Contrast Color check.
4. Print/Embroidery Quality & Placement Check.
5. All process S.P.I check.
6. Oil Spot/Dirty Spot Check.
7. Main Label Care label & Care Symbol Check.
8. Any Fabric Fault & Fabric Reject Check.
9. All process Measurement Check.
10. Blister Poly & After Poly Getup Check.
11. Hang tag & Price Sticker Check.
12. Assortment Every Carton Pcs Quantity Check.
13. Buyer Requirement Wise Ctn Size, Poly Size, & garments Size Check.

E. Out Side Print & Embroidery Quality Check List: 

1. Buyer Approved Sample or Artwork Wise Bulk Sample Print & Embroidery Design Check.
2. Size Wise Approved Pattern Placement Check.
3. As per Sample Wise Print Design, Color & Quality Check.
4. Bundle & Size Wise Print/Embroidery Check.
5. Fabric Top Side in Side Check.
6. Print / Embroidery Pattern Placement Check.
7. As Per Sample Wise Print/Embroidery Design, Thread Color Quality Check.
8. Print/Embroidery Color Wise Wash Test Check.

F. Store Quality Check List: 

1. Buyer Approved Trims Card Check.
2. Buyer Approved Sample Wise Main, Size & Care Label Check.
3. Buyer Approved Sample Wise Care Symbol Check.
4. Thread Color Shading & Quality Check.
5. Buyer Wise Hang tag & Price Sticker Check. 

Author of This Article: 

Noor Ahmed Raaz

B.Sc. in Fashion & Design

University of Chittagong

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