Mercerizing is done after bleaching operation. Bleaching is enough for prepared the fabrics for dyeing and printing but mercerizing is done for adding some advantage to the fabric. Luster and strength of the fabric increases for mercerizing process. Cotton mercerizing is the most popular operation.
Mercerizing of cotton is done in three basic stages of materials. They are as:
- Hank form
- Package form
- Beam form
- White fabric
- Woven fabric
- Knitted fabric
Methods of application: Yarn or fabric can be mercerized by J-Box. Mercerizing is a continuous process. At first fabric is hanked by the roller in a J-Box. Fabric is passed through a solution which contains 23% NaOH at room temperature. Fabric is passed for 4-5 minutes. Then fabric is squeezed by the squeezed roller and washing is done in a bath at 85 degree Celsius. Then it also immersed in an acid solution bath which contain 5% CH3COOH. After that is washed in another bath at 85 degree Celsius. By this way we can get a mercerized fabric.
For white finished goods, mercerizing is done by the following sequence:
Fabric after scouring and bleaching process
Padding in alkaline liquor
Neutralization in acid solution
A marketable fabric can be produced by different way. But day by day man wants to wear that’s type of fabric which has all possible facilities. Mercerizing is done in different types of machine. Generally mercerizing is done in dyeing machine. Yarn and Fabric Mercerizing is near similar.
Different well known buyer wants to get mercerized products. They strictly follow the qualities of product. After mercerizing fabrics become more suitable for dyeing or printing or for white goods it ready for delivery to buyer.
Mercerizing is one of part of wet processing technology. Mercerizing is the special type of treatment. Mercerizing is done for get some special properties of the textile materials. By the mercerizing process the physical properties of the material changes. After scouring and bleaching process, mercerization is done.
Mercerizing is the process of subjecting a vegetable fiber to the action of a fairly concentrated solution of a strong base (Sodium hydroxide 50-70 deg Tw and 18 degree Celsius temperature) so as to produce great swelling with resultant changes in the fiber structure, dimensions, morphology and mechanical properties.
Mechanism of Mercerizing: We know that fiber cell structure is different from one to another. Some cell structure is triangular, some are oval, some are hexagonal, and some are zigzag and many more. When light falls on that cell it reflects the light as per its cell structure. Sometime this reflection is regular, some time it is not. It affects the luster of the fabric surface. For getting a regular reflection from the fiber it pass through a process called mercerizing process.
By mercerizing process the strength of the fiber increases up to 20-30%. Cotton fiber’s shape become round when it shrink in the solution of caustic soda (NaOH). The lumen becomes small and the cell wall become greater for this reason, strength of the fiber increased. The surface of the fabric become fine and light reflects on it constantly; so the luster of the fabric increase, the swelling power of the fiber also increase. Generally low twisted yarn is suitable for mercerizing. Mercerized fabric is more suitable for dyeing and printing than the bleached fabric.
Effects of mercerizing: Different types of changes are occurred for mercerizing in the cotton fabric. Following changes are the most important:
- Shrinkage in the area of the fabric.
- Tensile strength of the fabric increases.
- Fabric luster also increases.
- Hygroscopicity of the fabric increases.
- Capability for absorbing dyes increases.
- Preferential absorption of sodium hydroxide during the treatment.
- Mercerizing increased action of lower temperature.
- Possible compound formation soda cellulose.
Luster of the fabric is the most vital point. Attraction of the fabric depends on the luster of the fabric. Luster of fabric depends on various factors. They are as follows:
- Cross-section of the fiber.
- Staple length of the fiber.
- Wall thickness of the fiber.
- Concentration of Sodium hydroxide.
- Temperature of the mercerizing solution.
- Percent stretch.
- Yarn construction.
- Yarn twist.
- Doubling of yarn.
- Degree of singeing.
- Application of tension.
- Rate of drying.
Mercerizing increases the luster and strength of the fabric. Generally mercerizing is done for cotton. Mercerizing depends on the requirement of buyer. The price of the mercerized fabric is higher than bleached fabric.
In this present age every man wants to get most benefit from his investment. For this reason they are interested to get maximum output from low input. To ensure that one should be careful before start a project. One should be calculative in every steps of investment. Poor management could be harmful. So management should be strong. Skilled personnel are needed for that. Man, Machine, Money Should available. I represents some suggestions to improve the productivity of jute mills as well as textile sectors and others industry.
Way to improve productivity in jute mills:
- Standard moisture content in jute should be ensured.
- Moisture content and correct weightiest of jute received in jute mills should be properly recorded in the register meant for the purpose under attention by the competent officers on jute and batching department.
- Process stock taking should be done by carefully in terms on last Friday of every month in accordance with the guide line enclosed. They should be composed of –
- Project Head
- Accounts Head
- Production Manager
- Deputy Manager
- Concern Department
- Quantity of jute received in batching department should ensure.
- Regular checking on the procurement and issue of actual quality of Jute Batching Oil (J.B.O) by competent personnel is must.
- Preparation and application of emulsion on jute should be properly.
- Jute should be conditioned properly in the batching department. Even cut jute should be conditioned at least of 24 hours.
- Correct grade and quality of jute should be received in the jute department.
- Maintenance department must ensure proper setting and gauging of different rollers of carding machine.
- Proper carding ratio for different qualities of yarn should be regularly checked and maintain.
- The surface of the tin cylinder should be uniform and smooth.
- Standard twist for respective yarn should be maintained and excessive twist should avoid.
- Thread wastage should be minimized and bring down to standard as per guide line.
- Starch ingredient should be checked. Over drying and under drying in sizing should be avoided.
- Weaving and finishing department should ensure the application of water in dry beaming and damping.
- Recovery of the caddis from dust must be ensured and only actual dust should be thrown out after proper weightiest and entry into the register.
- Standard packing of finished goods must be ensured. In dry case it should never exceed 0.5 to 1% and standard for Hessian, Sacking C.B.C respectively.
- Representation of jute and batching department responsible for checking issue and receipt of raw jute should be placed frequently.
At last, the main factors to improve productivity through optimum utilization of the inputs may be listed as:
a) Human resource which requires careful handling for optimum output.
b) Control of input materials in terms of quality, quantity and cost.
c) Overall calculation is needed to reduce losses in the industry.
So, we can implement above factors in our practical life. I am sure production process loss will reduce and productivity will improve. One will reach his/her goal.