Developing the Conceptual Analysis for Fabric Sourcing Properly on the Way of Garments Manufacturing

Developing the Conceptual Analysis for Fabric Sourcing Properly on the Way of Garments Manufacturing
Mohammad Shahadat Hossain
B.Sc. in Textile Engineering (Major on Apparel Manufacturing)
Daffodil International University, Bangladesh
Email: shahadat1859@yahoo.com

Abstract:
We must need fabric to manufacture garments. Fabric & it’s quality is the first concern for garments trade. Fabric quality is depending on yarn quality, color, finish & smooth processing stage for knitting/weaving, dyeing, finishing etc. Business profitability is deeply involved with fabric as it is major portion of Garments. So the total sourcing of Fabric is including not only for technical concern but also for business profitability.

Introduction:
Fabric is the core part of garments. Quality of Garment is mostly dependent on fabric quality. So effective garments production is depending on right fabric collection. For garments manufacturing, we are sourcing fabric locally or globally. We need to be technically concerned from the customer’s point of view as well as we need to be more thankful & business minded for Fabric sourcing. We are sourcing Woven fabric & Knit fabric for manufacturing of Woven or Knit Garments. In this article, I am trying here to depict total aspect either for Woven Fabric/Knit fabric Sourcing.

Specification:
To specify particular fabric, specification is must because if we don’t specify about fabric while giving order to supplier, we can’t get proper/expected fabric. If we find certain particulars incorrect & complain to supplier, they have the right to say that the things we complain about were understood & accepted by us. Then there will be no point to claim or argue since no relevant specifications were detailed in the contract. In order to avoid this kind of detrimental ambiguity, when we order fabrics, we should spell out our specifications as much as possible.

The considering point which should be included:

1. Fabric type.
2. Fabric composition
3. Fabric construction
4. Yarn count of warp & weft for woven, knitting yarn count for Knit fabric.
5. What kind of yarn (OE.,ring spun, a grade, fully combed, semi combed or carded)
6. GSM of fabric or oz/sq yard for denim fabric
7. Width of fabric for woven & machine dia for knit fabric.
8. What types of dye or what color fastness standards we need.
9. Finish( consider that what you need as per suitability of your fabric)

Fabric testing:
Fabric should be tested on testing lab to evaluate the characteristics, we need. For testing, you must maintain standard given by the worldwide standardization body. Recognized testing authority are SGS, ITS, Bureau Veritas etc. Fabric can be tested on factory’s own lab depending on it’s availability. You have to ask the supplier about this matter. Necessary testing which are commonly needed on fabric stage is given below with their standard.

Fabric testing

Base test/ physical test:
These tests are used related to fabric base/ physical appearance

1. Composition test
It’s defining fibre content/types of fibre & their percentage of content used on respective fabric.i.e.; 100% Cotton, 85% Cotton 25% polyester etc.

2. Fabric weight (GSM):
Weight or heaviness/lightness of fabric is determined by GSM. It’s calculated by using GSM cutter & weight balance. GSM is variable depending on fibre content, structure of fabric & finish of fabric.

3. Strength test

• Bursting strength for knit: This test is done to evaluate the strength of knit fabric. The standard result should be 250 kpa/350 kpa & above. Test method: BS EN ISO13938-2:1999

• Tensile strength for woven: This test is done to evaluate the strength of woven fabric. The standard result should be 12 kg to 20 kg depending on gsm i.e; 12kg for less than 120 gsm, 15 kg for greater than 120 gsm but less than 250 gsm, 20 kg for greater than 250 gsm. Test method: BS EN ISO13934-2:1999

• Tearing strength for woven: This test is done to evaluate the strength of woven fabric.The standard result should be 800 g to 1.5 kg depending on gsm i.e.; 800g for less than 120 gsm, 1 kg for greater than 120 gsm but less than 250 gsm, 1.5 kg for greater than 250 gsm. Test Method: BS EN ISO: 13937-1:2000

4. Shrinkage test/ Dimensional stability:
This is the test for evaluation of shrinkage after wash for what this test is known as stability to washing. For weft knitted fabric, standard result should be +7% to -7% (+2% maximum on interlock or rib) & for warp knit fabric -5% maximum. For woven fabric +1% to -3% maximum should be the standard value. Test method: BS EN ISO6330:2001 

5. Spirality test only for single jersey:
This test is done only for single jersey fabric & standard result should be 5%. Test method: ISO163222-2:2005

6. Elastic Recovery test:
This test is done only on elastane contained fabric.

7. Martindale Abrasion resistance test:
This test is done on Woven or Knit fabric to measure resistant property against abrasion.

8. Martindale Pilling resistance test

Bulk test: 

1. Color fastness test to Wash
2. Color fastness test to Water
3. Color fastness test to Rubbing/ Crocking
4. Color fastness test to Light

Formaldehyde test:
This test is uncommon. It can be on base test or on bulk test.

Fabric color:
Fabric color is very sensitive & vital issue for sourcing fabric. When you want to source fabric, you should have proper idea of fabric color & strategy to get properly colored fabric. At first you have to submit physical swatch of your required fabric or pantone number to supplier/respective dyeing manager. At that time, you should also mention quantity of fabric, you need. Then they will give you the lab dip according to your color reference. Lab dip should be of three option i.e.; option A, option B & option C. Then dyeing section dye fabric for color approval of bulk production. For shade matching, Data color machine or Spectrophotometer should be used. Compatibility of fiber & dyes, we should have the knowledge about which dye is suitable for what fabric:

Fiber	Suitable dyes
Cotton/cellulosic fiber	Direct, Reactive, Vat, Sulpher, Azoic, Mordant , Pigment & Mineral dye
Wool,silk/protein fiber	Acid dye, Reactive dye, Mordant dye
Jute	Basic dye
Nylon	Acid dye, Disperse dye
Acrylic	Basic dye, Disperse dye
Acetate, Polyester	Disperse dye

 

We should have the knowledge about key properties of dyes:

Dyes	Key properties
Reactive dye	Fastness properties for wash, light, rubbing, perspiration are usually good. All shade is found, dyeing method is easy & price is cheaper. Water soluble dye & high electrolyte is necessary for dyeing with reactive dye.
Direct dye	Easily dissolved in water, easily diffusible into fiber & have strong affinity to cellulosic fiber. Various shades are found & comparatively cheaper. It has moderate light fastness property but wash fastness is not so good (2-3).
Acid dye	Easily soluble in water & have direct affinity towards protein fiber. Much bright shade is found. Wet fastness is very good but light fastness is moderate.
Vat dye	Water insoluble dyes & application process is difficult. Dull shade is found. Color fastness property is very good except rubbing fastness which is not so good. More expensive dyes.
Basic dye	Soluble cationic dye which has affinity towards anionic substrate i.e; protein fiber. Exhibit an unlimited shade range with high tinctorial strength, brightness & many colors are having fluorescent characteristics. The water solubility is very good in presence of glacial acetic acid but leveling power is poor. Light fastness is poor to moderate but wet fastness is good.
Disperse dye	Disperse dyes are molecularly dispersed. Very less soluble in water which makes fine dispersion. Light fastness is fair to good (4-5). Washing fastness is moderate to good (3-4).
Sulpher dye	Contain sulpher linkage within their molecule. Water insoluble dyes. Heat reduction & oxidation of the development of the dye. Wash fastness is excellent, wet fastness is good & light fastness is satisfactory.

 

Dyes are known by their commercial/brand name. The brand/commercial name, manufacturer & manufacturing country of some dyes are given below:

	Brand Name	Manufacturer
Basic dye	Astrazon	Bayer (Germany)
	Basacryl	BASF (Germany)
	Sevron	DU Pont
	Maxilan	Ciba (Switzerland)
Acid dye	Sandolan E, N, D, Fast, P,MF	Clariant
	AcidolK,M, Palatine Fast	BASF
	Telon	Dystar
	Novamina	ACNA (Italy)
	Polar	Ciba (Switzerland)
Vat dye	Caledon	ICI (U.K)
	Cibanone	Ciba-Geigy (Switzerland)
	Indanthren	BASF, Bayer (Germany)
	Sandothrene	Clariant
	Calcoloid	USA
Direct dye	Benzo, Benzoform, Benzamine, Sirius, Sirius supra	F. Bayer (Germany)
	Cuprantine, Diphenyl, Solophenyl	Ciba-Geigy (Switzerland)
	Cholorazo, Durazol	I.C.I (U.K)
	Benzanil	Yorkshire (U.K)
	Azoform, Pyrazol, thiazol, solar	Sandoz AG (Switzerland)
Reactive dye	Procion	I.C.I (U.K)
	Ciba cron	Ciba (Switzerland)
	Remazol	Hoechst (Germany)
	Levafix	Bayer (Germany)
	Reactone	Geigy (Switzerland)
	Primazine	BASF (Germany)

 

Fabric Finishes:
Grey fabric need to be brought in touch of several finish to use. These finishes can give better appearance & performance as well as enhance structural properties of fabric. The whole cycle of finishing consists of mechanical and chemical processes, which are used depending on the kinds and end uses of the fabric. Mechanical processes include drying, calendaring, embossing, sueding, raisingetc and chemical processes include in the application of special substances on the fabric, impregnation with size, starch, dextrin and other polymeric substances. There is a wide range of finish we use on fabrics:

1. Easy care
2. Non iron
3. Peach
4. Regular
5. Teflon
6. Water repellent
7. Soil release
8. Active cleaning
9. Resin finish
10. Lubricant finish

Consciousness to get right product at right time:

• At first we should determine our requirement of fabric, which we need & then check with several suppliers for development. 

• Evaluate the developed fabric from all aspect of quality & select developed sample which is meeting requirement.

• Asked offered price from suppliers from which you get suitable sample as per your requirement. Evaluate offered price by the mind of business, i.e.; should be concerned about the terms of pricing like: FOB, C&F, Ex-fty etc. 

• Also need to evaluate lead time of getting the fabric & origin of suppliers as transportation & C&F purpose is variable from place to place.

• Then you can place order with your suitable one & closely follow up to get the fabric at right time. 

• Followup process is including taking delivery confirmation both for sample & bulk, payment proceeding, reminding timely to get updated, advising ship mode & forwarder, taking necessary docs to release the goods & arrange C&F to release the goods.

Strategy to select right fabric:
As a buyer or Merchandiser, we should be very careful & practical oriented on every stage up to get the bulk fabric. At first we have to give clear specification to supplier, then ask them & follow up regularly to give you the sample/fabric swatch. Evaluate the quality & if it is approved, then negotiate about the price. You can choose with two, three or more suppliers at a time to get better feedback. We should have the proper knowledge about the construction, gsm & count of the fabric:

Relation between count & gsm of knit fabric:

• Single jersey  : Yarn count= -.141 X Gsm+50.22
• Single pique/lacoste : Yarn count= -.146 X Gsm+57.16
• Double lacoste  : Yarn count= -.167 X Gsm+64.36
• 1X1 Rib  : Yarn count= -.123 X Gsm+54.57
• Lycra 1X1 Rib  : Yarn count= -.119 X Gsm+59.12
• Interlock  : yarn Count= -.206 X Gsm+80.56

We can also follow the following chart for this purpose:

100%Cotton	Finished GSM
Yarn Count	S/j	Pique	Interlock	D/N	1X1 Rib	2X2 Rib
20/s	195-230	240-270	N/A	N/A	270-300	280-320
24/s	180-190	220-235	N/A	N/A	240-260	250-270
26/s	160-180	200-220	300-330	300-330	210-230	220-240
30/s	130-150	170-185	250-290	250-290	180-200	190-210
34/s	115-125	150-170	220-240	220-240	165-175	170-180
40/s	N/A	140-150	190-210	190-210	N/A	N/A
46/s	N/A	N/A	175-185	175-185	N/A	N/A

 

For woven fabric, by using the following formula we can get the clear concept about gsm & yarn count:

Woven fabric construction: EPI XPPI/Warp Count X Weft Count

GSM= [{EPI/ (Warp count/10)} + {PPI/ (Weft Count/10)}]/13 X33.901

For Example:
Fabric construction: 108x58/20x20
GSM= [{108/ (20/10)} + {58/ (20/10)}]/13 X33.901
        =216.44

Conclusion:
Fabric Sourcing is a vital part of Garments merchandising as well as Manufacturing of garments. I am trying here to express a view to source fabric properly. I think, we should be more proactive to use our technical view for sourcing of fabric. From my belief, we will increase higher profitability as well as best quality by concentrating on proper fabric sourcing.

References:

1. How to be a smarter Garments Merchandiser by Conway Liu
2. Dyeing & Chemical Technology by E.R Trotman
3. Textile testing by J.E booth
4. Knitting Technology by Spencer
5. Project work on Interstoff Apparels Ltd, Chandura, Gazipur, Bangladesh & Renaissance Sourcing Ltd, Gulshan-2, Dhaka-1212, Bangladesh