Yarn mercerizing process in textile:
Other yarns are usually not mercerized except for the colored yarn used to make sewing yarn and check fabrics. Mercerize yarn from fabric mercerize are convenient for many reasons. https://bdfabric.com/mercerized-cotton-in-the-textile/
There are usually two ways to mercerize yarn. E.g.
1. Hank mercerizing process
2. Warp mercerizing process
1. Hank mercerizing process:
Although the Hank Mercerizing method is old, it is still widely used today. This method is a batch method. Here the yarn can usually be mercerized in the form of a hank on the gray stage, either dry or wet. Mercerizing the yarn while it is wet reduces the concentration of caustic soda solution in it.
When mercerized in dry condition, it is necessary to add 0.5% to 1% excellent wetting agent in a caustic soda solution. When this wetting agent is strong the yarn by caustic swells quickly and evenly everywhere. Later it can be easily removed by washing. For mercerizing in the shape of a Hank, the hinges are arranged one after the other between two parallel rollers in the mercerizing machine.
The rollers of the Hank Mercerizing Machine are rotated by two belts and pulleys which are attached to the gear wheel. The spindle and worm wheel are used to hold the tension in the Hanks by hand or to relieve tension. An alkali tray is placed under the rollers, which can be lifted with the help of handles.
When the mercerizing liqueur tray is lifted, it comes in contact with the yarn (hank) and is treated with liqueur by the rotation of the roller. The alkali is then removed by squeezing with a rubber roller. The alkali is then lowered onto the track and the water is brought down the hook on the watery track to wash the hank and is washed by a pipe.
Hank mercerizing process in textile:
At this point, Hank is kept in tension so that the yarn shines. Hank is then removed by a surface squeezing roller. Hank is then relieved of tension. Here the concentration of the alkali solution is 50° -55° (Tw) and the temperature is kept from 15°C to 18°C. The yarn is soaked in this solution for 3 minutes. The yarn is then treated with 1 to 3% sulfuric acid solution to remove the alkali. Later, when treated with a little ammonia, the effectiveness of the alkali is lost. The yarn is then dried well. Hank is washed and neutralized by mercerizing. Then it is dried and wrapped in a cone. Examining the brightness, strength, elasticity, etc. of this finished yarn, the following information is available.
1. The brightness of the finished yarn is very close to that of mercerizing at the same tension by any concentration of alkali solution above 30° (Tw).
2. Uneven dyeing is observed during subsequent dyeing of yarns mercerized by weak alkali solution.
3. Mercerizing with a certain concentration of alkali solution increases the tensile strength of the yarn and increases its luster and decreases the color absorption capacity.
4. Although maximum tension is applied during mercerizing to prevent yarn contraction, its strength does not change significantly.
5. When the tension of the yarn is high, the elongation of the finished yarn decreases.
2. Warp mercerizing process:
In some cases, yarn mercerization is more advantageous than fabric mercerization. Especially in the case of yarn used in knitted fabrics. Where mercerizing knitted fabrics without a special field is very difficult. Cotton yarn is also knitted with silk, wool, rayon, and other fibers. Although mercerizing fabrics are easier, less expensive, and faster than yarn, there is a special effect on fabrics woven with mercerized warp yarn.
In this case, the maximum strength and brightness of the yarn are increased. As a result, this increase in energy increases the weaving efficiency. The warp mercerizing process is a continuous process. In this method, several thousand warp yarns with a length of 5000 to 5500 meters are continuously mercerized at the same time.
Yarn mercerizing process in textile. In this method, the yarn is handled so that there is less handling. The yarn is automatically dried directly from the scroll in a row and then wrapped directly in a bobbin or school. This method is advantageous as it has a lower chemical cost than the Hank Mercerizing method.
Since the yarn is usually mercerized in the gray state, the standard wetting and Penang agent is added to the caustic soda solution. In this case, the tension of the yarn is kept under special arrangements.