Introduction: 

The wide consumption of denim by fashion globally has created a new opportunity for Bangladesh. The industry in Bangladesh presently has 30 denim producing factories with total investment of over USD 1 Billion. The monthly productions of denim stands at 30 million yards per month while the demand of nearly 60 million yards. To fulfill the balance demand, imported 30 to 35 million yards per month from countries like China, India & Pakistan which average value is USD 75 million. In this article I will give production of denim fabric with process flowchart. 

Fig: Denim fabric production

Denim fabric production section: 

Yarn store section. 
↓ 
Warping section. 
↓ 
Weavers beam preparation section( Scouring, Dyeing, sizing section) 
↓ 
Weaving section. 
↓ 
Finishing section (Singing, Mercerization). 
↓ 
Fabric store. 


Warping section: 

Cone from winding. 
↓ 
Creeling. 
↓ 
Control system 
↓ 
Reed 
↓
Measuring device 
↓ 
Winding on beam .

Weavers beam preparation by continuous method: 

1. Warp beam creeling. 
2. Scouring 
3. Dyeing: Slasher dyeing is done for warp yarn. There have two ways for dyeing such as (bottoming and tapping.) 

***Bottoming Process: 

Sulphur Dyeing. 
↓ 
Washing. 
↓ 
Indigo dyeing. 
↓ 
Washing. 
↓ 
Oxidation. 
↓ 
Washing. 


*** Topping process: 

Indigo dyeing. 
↓ 
Washing 
↓ 
Sulphur Dyeing. 
↓ 
Washing. 
↓ 
Oxidation . 
↓ 
Washing.

4. Sizing. 
5. Weavers beam. 

Weaving section: 

1. Air jet loom used for producing fabric. 
2. Example of Loom card.

·         Weave design: 3/1 R.H.T

·         EPI & PPI: 65 & 42.

·         Total ends: 4440.

·         Beam length: 2000m.

·         Fabric construction:

            7.2RS * 6OE

            65 * 42

·         Total air jet loom: 66

Finishing section:

1.      Singing and desizing process.

2.      Mercerization process.

Quality control in yarn dyeing section: 

***Offline quality control:

·         Yarn breakage.

·         Pump pressure.

·         Warp beam creeling.

***Online quality control:

·         Temperature.

·         Shade%.

·         Dyeing solution feeding.

***Product control:

·         Strength test.

·         Check shade%.

·         Fastness properties test.

·         Oil spot.

·         Impurities in yarn.

Quality control in weaving: 

***Offline quality control:

·         Thread breakage.

***Online quality control:

·         Auto selvedge cutting.

·         Tension maintain.

***Product control:

·         GSM of fabric.

·         EPI and PPI.

·         Fabric shade%.

·         Oil spot.

·         Strength test etc.

Instrument used for sample testing: 

***Matrohm machine:

·         Testing the indigo in the sample g/l.

·         To determine redox in dyed sample.

·         To measure pH

Conclusion:

 
Finally with the help of this topic we learned about the denim fabric production process. We also learned about different process and function of different equipment that is used for the denim fabric production.