Fabric mercerizing process in textile:
The principle of mercerizing cloth and the mercerizing yarn is the same but it is necessary to keep the cloth tense on both sides. So that the length and width of the fabric are always in tension. Fabrics are usually mercerized for brightness and to increase the color absorption capacity. https://bdfabric.com/yarn-mercerizing-process-in-textile/
Two types of machines are commonly used for mercerizing cloth. E.g.
1. Pad-chain type machine
2. Pad-chainless type machine
1. Fabric mercerizing process in textile-Pad chain type machine:
First, the scoured and bleached cotton cloth is subjected to 55° – 65° Towadel (Tw) concentrated Caustic Soda (NaOH) solution in a padding mangle for 2 to 3 minutes with tension at 18°C. The padded cloth is then squeezed with a squeezing roller and washed with hot water at 70°C with a certain tension. The cloth is then washed twice in cold water (once the tension is loosened). Fabrics washed in cold water are washed with 1° (Tw) sulfuric acid solution to remove residual caustic soda and then washed and dried.
2. Pad-chainless type machine:
No mangle pads or chains (stenters) are used in this method. The main feature of this machine is that the mercerizing process is done by keeping the fabric under tension. In some of these, the fabric is mercerized and washed by keeping the shape and size of the fabric with the help of a roller. In this machine, it is necessary to use a wetting agent with caustic soda solution as there is no system of angle pressure or squeezing. In this method, multiple fabrics of the same fleet, shape, and yarn can be mercerized simultaneously. There are tension pulleys to increase or decrease the tension of the fabric. For light fabrics usually, 45 to 65 pounds of pressure is used. There is a use of 250-pound pressure for thick cloth.
The cloth is usually inserted into the caustic solution container with the help of two low rollers. At the same time, two pipes are used to pour the caustic solution from the tank onto the top two rollers to improve the drying action of the cloth. In this case, the fabric usually travels 3-4 yards, and then it passes 6 yards in contact with other rollers so that caustic can penetrate the fabric well. The cloth pressure then passes through the inside of the mangle.
Again the cloth goes 8 yards ahead. This is the time when clothes are mercerized with caustic solution and it takes 40 to 60 seconds. The cloth is then taken to the front with the help of a roller and washed with hot water at a temperature of 70°C. Here clothes are washed by spraying hot water or by the counter current. And the cloth is then thoroughly washed in clean cold water. In this machine, 9-26 yards of cloth is mercerized per minute, but if two cloths are mercerized at the same time, the speed is kept a little less.