Dyeing is the combination of reaction among fiber, dyes, chemicals and water. In dyeing process different faults can be occur for various factor. Among all of the dyeing process, package yarn dyeing is different. In package yarn dyeing different types of faults are occurs but following are the most common.
Uneven dyeing: A textile engineer must have knowledge about the shade of color. Small percentage of shade difference can move a material to rejection. So, it needs to be high care full during dyeing. Dyeing is a continuous process and during dyeing ones should be sure about the shade of materials that it matched with the standard swatch. Uneven shade means the variation of shade in different layer of a yarn package. We know that package yarn dyeing is done by the In-0ut mechanism of dye liquor. So shade could be varying in various layer of a package. Followings are the causes and remedies of uneven shade.
→ Improper color dosing.
→ Using dyes of high fixation property.
→ Uneven heat-setting in case of synthetic fibers.
→ Lack of control on dyeing m/c
→ By ensuring even pretreatment.
→ By ensuring even heat-setting in case of synthetic fibers.
→ Proper controlling of dyeing m/c.
Batch to Batch Shade variation: In dyeing; dyeing is done according to the buyer requirement. An order for a specific shade could be small amount or large amount. In mill, different batch is made as per order or depending on the capacity of the machine. For this reason batch to batch shade variation could be take place. Followings are the causes and remedies way of batch to batch variation.
→ Fluctuation of Temperature.
→ Improper dosing time of dyes & chemicals.
→ Batch to batch weight variation of dyes and chemicals.
→ Dyes lot variation.
→ Improper reel speed, pump speed, liquor ratio.
→ Improper pretreatment.
→ Use standard dyes and chemicals.
→ Maintain the same liquor ratio.
→ Follow the standard pretreatment procedure.
→ Maintain the same dyeing cycle.
→ Identical dyeing procedure should be followed for the same depth of the Shade.
→ Make sure that the operators add the right bulk chemicals at the same time and temperature in the process.
→ The pH, hardness and sodium carbonate content of supply water should check daily.
So, friends make sure about the yarn dyeing faults and take steps for remove it.