Study on desizing of cotton fabric by using enzyme

Name of the experiment: Study on desizing of cotton fabric by using enzyme.

Theory:

Desizing is the process of removing the size material from the warp yarns in woven fabrics. Sizing agents are selected on the basis of type of fabric, environmental friendliness, ease of removal, cost considerations, effluent treatment, etc.

Desizing, irrespective of what the desizing agent is, involves impregnation of the fabric with the desizing agent, allowing the desizing agent to degrade or solubilise the size material, and finally to wash out the degradation products.

Enzymatic Desizing:

Enzymatic desizing is the classical desizing process of degrading starch size on cotton fabrics using enzymes. Enzymes are complex organic, soluble bio-catalysts, formed by living organisms, that catalyze chemical reaction in biological processes. Enzymes are quite specific in their action on a particular substance. A small quantity of enzyme is able to decompose a large quantity of the substance it acts upon. Enzymes are usually named by the kind of substance degraded in the reaction it catalyzes. Amylases is the enzyme that hydrolyses and reduces the molecular weight of amylose and amylopectin molecules in starch, rendering it water that is soluble enough to be washed off by the fabric. Effective enzymatic desizing require strict control of pH, temperature, water hardness, electrolyte addition and choice of surfactant.

Advantages of Enzymatic Desizing:

• No damage to the fibre.
• No usage of aggressive chemicals.
• Wide variety of application processes.
• High biodegradability.

Disadvantages Enzymatic Desizing:

•  Lower additional cleaning effect towards other impurities, no effect on certain starches (e.g. tapioca starch) and possible loss of effectiveness through enzyme poisons.

Object of the experiment:

1. To know about desizing process.
2. To know about how to work at lab for desizing.
3. To know how to calculate the recipe.
4. To make solution for desizing.
5. To make a well report.

Recipe:

• Enzyme = 2cc/l
• Leveling agent = 1.5cc/l
• Wetting agent = 2cc/l
• Sequestering agent = 1.5cc/l
• Acetic acid = 1cc/l
• Time = 60min
• Temp = 60℃
• pH = 4-5
• M:L = 1:15
  

Calculation:

• Fabric weight = 5.12gm
• Enzyme = 0.01024cc
• Leveling agent = 0.00768cc
• Wetting agent = 0.01024cc
• Sequestering agent = 0.00768cc
• Acetic acid = 0.0055cc
• Total liquor = 76.8cc
• Fresh water = 76.75cc

Working procedure:

1. Firstly cut the fabric from sample. Weight the sample fabric.
2. Calculation the recipe. Then make solution.
3. Wet the sample fabric. Put in the solution jer.
4. The jer put in machine.
5. Setup the machine & start.
6. Finish the process at 60 min in 60℃. Put out the sample & wash.
7. Then dry the sample & add the sample with report.

Wastage:

Wastage = (Desizing befor fabric weight - Desizing after fabric weight) 

               = (5.5 - 5.12)gm = 0.38gm

 

Conclusion: 

This practical is very important in our life. By this practical we know how to desizing. All work done very carefully use to acid. Thanks to my teacher who teach me.