What is enzymatic Desizing? Effect of temperature on enzymatic desizing :

Enzymatic Desizing

Enzymatic desizing uses enzymes to remove the size which was applied on the fabric. Enzymes are high molecular weight protein biocatalysts. These can be extracted from animals, plants or bacteria. They are specific in action.

Title:

To observe the effect of temperature on enzyme desizing of 100% cotton fabric.

Abstract:

In this experiment we were having the task to perform enzymatic desizing of fabric sample at different temperature that was presented to us .The fabric samples were provided to us which had different weights respect to each other and we have to undergo the process of enzymatic desizing for each of them with change in amount of temperature applied. The desized fabric after experiment was related with griege fabric sample ton relate absobancy. Tegewa rating was checked and hand feel for each sample respect to griege fabric was also observed.

Introduction:

Desizing is the process wherein the size carried out to the warp yarn earlier than weaving is removed to facilitate the penetration of dyes and chemical substances within the subsequent wet processing operations. In the system of desizing, not only sizing agents, however additionally a few natural impurities are eliminated from fibres. In desizing, the starches and polymers which are applied which are insoluble, are transformed into water soluble compound to ease of their elimination. Desizing of cotton material may be achieved by way of bodily, chemical or combination of physical and chemical mechanism, specifically rot steeping, acid steeping, remedy with enzyme and oxidizing agents.

Desizing has the following types:

· Enzymatic desizing of starches on cotton fabrics

· Oxidative desizing

· Acid desizing

Acid Desizing :

In this approach cotton fabric is dealt with with dilute sulfuric acid with a awareness of 5-10 g/1 at a temperature of approximately 40oC for 3-4 hrs. Dilute acid attacks the polymer chain of starch and due to chain cleavage of starch molecule brief water soluble or dispersible chain segments are shaped. The degraded starch is eliminated from the cloth by means of everyday washing remedy.

Enzymatic Desizing:

This experiment was done by the process of enzymatic desizing. Enzymatic desizing uses enzymes to remove the size which was applied on the fabric. Enzymes are high molecular weight protein biocatalysts. These can be extracted from animals, plants or bacteria. They are specific in action. The processes performed through enzymes are more environmentally friendly. The enzymes used for starch degradation are amylases hydrolyzing the starch into water soluble product. Moreover, the amylases have no effect on cotton structure. Enzymes are very sensitive to temperature and pH so while working with enzyme one should keep in mind this point.

Enzymatic desizing is much more better than the other two of the desizing procedures because firstly it is very fast as compared to acid and rot desizing and secondly it is environment friendly and last but not the least as compared to acid no damage is done to the fabric.Thats why enzymatic desizing is by far the mostly used method in industries.

Oxidative Desizing:

In oxidative desizing the risk of damage to the cellulose fiber is very high and its use for desizing is increasingly rare. Oxidative desizing uses potassium or sodium per sulfate or sodium bromate as an oxidizing agent

Materials and Method:

Materials:

Sized 100% cotton fabric
Distilled water
Wetting agent = 2g/l
Enzyme (Rucolase EPE 124) = 2, 4 g/l
Liquor Ratio = 1:50
PH = 6.5
Temperature = 90⸰c
Time = 45 mints

Desizing Procedure:

First of all 5 samples of 100% sized cotton fabrics were taken.The Samples were weighted on weighing balance. According to liquor ratio 1:50, distilled water was added to steel container. Calculated enzyme concentrations and wetting agent concentrations were added to those containers separately and set the pH according to given pH by adding given acid and base in the solution separately. Cotton fabric samples were dipped in container and heated in water bath at 90˚C for 45 minutes. Continuous stirring was performed for efficient desizing. Then the samples were further rinsed in cold water. The rinsed desized fabric samples were dried in oven at 120˚C for 5-6minutes.

Characterizations:

Hand Feel:

Took a sample of textile fabric and felt the surface of fabric with the help of index fingers and thumb before and after scouring process. The sized and desized fabrics were felt by hand to check softness and variation after desizing at different enzyme concentrations.

Weight loss:

Weight loss is defined as the amount of weight loss after the removal of sized material. The weight of cotton sample were measured at the start and the after the removal of starch were again measured and weight loss was calculated.

W1 = weight before desizing

W2 = weight after desizing

Weight loss % =

Tegewa rating

Drop of potassium iodide solution on desized samples were rubbed. The color variation was checked with TEGEWA color table.

Water Absorbency:

A drop of water was dropped on sample before desizing and samples after desizing. Time was noted for water drop absorbed into sample and was compared with the griege fabric..

Results and Discussion:

The fabric loss the weight after desizing process because the natural coloring matter and any other colouring matter is removed from natural fibers that is why the fabric loss it’s weight after process.

Weight loss%:

Table 1 Effect of temperature concentration on weight loss

Temperature (⸰C)	Weight loss%
40	8.9
50	12.9
60	10.8
80	9.4
90	12.92

Figure 1 Effect of temperature on the weight loss of fabric during de-sizing

The table shows that with increase in temperature the desizing efficiency also increase that’s why sample that was desized at 90⸰C has hight weight loss. It’s mean it’s good desized than that of other samples.

Tegeva Rating:

Table 2 Tegeva Rating:

Temperature (⸰C)	Tegava rating
40	5
50	6
60	4
80	7
90	7

Figure 2 Tegewa rating of fabric samples

Table (2) and Figure (2) present the Tegewa ratings of the samples of fabric. Higher the de-sizing of a sample higher the value of Tegewa. Tegewa ratting increase with increase in temperature . at 90⸰C temperature highest the value of Tegewa than that of other samples.

Hand feel:

Hand feel of the de-sized fabric was soft as compared to that of gray fabric. Sample e was having the softest hand feel as compared to other samples because large amount of sizing material was removed from it due to a relatively change in concentration of pH used in it.

Water Absorbency:

This water absorbency test shows that by changing the temperature of the solution the time it takes to absorb water were different.

Table 3 Effect of temperature on absorbency

Temperature (⸰C)	Time Taken(sec.)
40	8
60	3
70	2
80	0.89
90	0.7

Table show that at 90⸰C the time of water absorb is less than that of other temperatures.

Conclusion:

The conclusion we draw from whole of this practical was that in the enzymatic desizing process by increase in temperature of the solution the desizing efficiency also increase. Desizing at 90⸰C temperature is good than that of other samples which were desized at lower temperature from 90⸰C . Because at 90⸰C enzyme is active and it helps to degradation of starch.

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Hi. I’m Designer of Blog Magic. I’m CEO/Founder of ThemeXpose. I’m Creative Art Director, Web Designer, UI/UX Designer, Interaction Designer, Industrial Designer, Web Developer, Business Enthusiast, StartUp Enthusiast, Speaker, Writer and Photographer. Inspired to make things looks better.