The reason for the polyester cotton blended fabric color difference
2016-01-19 08:28 | writer: admin
1. Improper pre-processing
The pre-processing of polyester-cotton blended fabric can make a big difference to the quality of the fabric dyeing, for example, the quality of desizing, the effect of scouring and mercerizing, the extent of setting, the alkali content of fabric, if any index can’t meet the requirements, will be reflected in the dyeing.
Due to the fixation curve of disperse dyestuff is differ, when choose the dyestuff, should as far as possible to choose the fixation curve is close to the dye color matching, compatibility, good performance, avoid due to poor compatibility the color shade is hard to control, and form the color difference.
3.Improper pressure of continuous dyeing machine
Consider that the disperse dyestuff can’t effect directly to the fiber, so the first dyestuff should be increased 10% concentration, in order to prevent the lighter color during the beginning. And need to use spray nozzle to add dyestuff, avoid left/middle/right color difference as add dyestuff from single side. Control the dyestuff height is in the same level, avoid the front/behind color difference.
Due to the suspensoid of disperse dyestuff and vat dyestuff can’t effect directly to the fiber, and the water absorbing of polyester is poor, so during the precure, quick drying or both sides with different drying, it all easy to cause dye migration. Curing temperature and time are the key to the thermosol dyeing of polyester/cotton blended fabric.
The disperse /vat dyestuff one step or two step thermosol pad steaming dyeing is usually for dark color of polyester cotton blended fabric, deoxidation is the key of vat dyestuff dye cotton. The liquid of vat dyestuff should be prepared with continuous mixing according to the need.
6. Improper treatment
After the thermosol dyeing, the width is shrinked more, so during the finishing, should be stentering in a high temperature. Improper temperature control will be cause the color shade change for some dyestuff, especially the waterproof fabric, the color shade will be yellow discoloration after stentering, and the shade became difference after stentering, it should be pay more attention when develop sample, avoid the finished fabric is disagree with the standard sample.
7. The improper selection of greige cloth
Due to the change of the fiber/quality/cotton assorting of greige, and sizing all have big influence to the dyeing, so, the greige of different supplier under the same dyeing process usually obtain different color.