Fugitive dyes: Imaginary or Real?

Dyes that do not run or bleed are called fast dyes. A dye that runs or bleeds when the fabric contacts water or solvent is said to be fugitive. The fastness of the dye on the printed or dyed fabric is determined by (1) the affinity of the fiber to the dye stuff used in the dyeing process (2) the fixing or setting of the dye stuff in the dyeing process (3) the amount of loose dye not absorbed by the fabric. Fugitive dyes can occur in most fabrics including silks, wools, cottons, rayons, polyesters and nylon.

IMAGINARY BLEEDING

I have received some complaints of dye bleeding sent to my laboratory that turned out to be imaginary. On black and white fabrics with checks, stripes or black trimming on a white garment there is often an optical illusion of dye bleeding or color migration. When I sectioned off the white portion from the colored section it turned out to be an illusion of bleeding. I investigated the phenomenon and found that that the illusion is created by the way the eye receives the color. The effect of dye bleeding when observing black and white is known as Hermann’s grid. The effect can be observed by simply staring at black and white stripes and checks. Then isolate the white portion and you will see the imaginary staining or bleeding disappear. This is also one of the reasons why it is difficult to observe staining on a checked fabric when you look directly at it.

DYE BLEEDING PROBLEMS

Fugitive dyes may run into the area surrounding the dye or transfer from a dark lining onto an outer fabric. This is known as dye migration. Fugitive dyes may also run into another garment. This is known as dye transfer. The newly affected area will be color stained or streaked. The area from which the dye came from often does not show a color loss. Dye bleeding may occur in normal wear from perspiration, spillage of food or soft and hard drinks. Dye bleeding may also occur in drycleaning, spotting or wetcleaning. Inspect garments when accepting them for dye bleeding on the underarm, waist and collar area due to perspiration. Check stained areas for dye bleeding.

SPOTTING

When spotting, use a cloth under stained areas. Check cloth after flushing and note dye transfer. When spotting fabrics that may have fugitive dye, use the steam gun with caution. Work in small areas, always flushing into cloth. Dry rapidly with the air gun. Do not enter the garment into the drycleaning machine while it is damp or wet. Avoid the use of wetside chemicals which accelerates the bleeding of fugitive dyes.

DRYCLEANING

Some garments with fugitive dyes may bleed when drycleaned. If no water is used in the drycleaning system, the condition can usually be corrected by simply re-cleaning. Do not use soaking action to correct dye bleeding. The garment that has the bleeding problem must have proper agitation to reduce dye bleeding. Use normal extraction and dry accordingly.

WETCLEANING

Dye bleeding occurring in wetcleaning frequently occurs on loads requiring mild agitation. Garments that bleed due to lack of agitation may only require running the garments over again with adequate agitation. It might be necessary to do this several times.

SPOT BLEACHING

Some dye bleeding that cannot be corrected in re-cleaning and re-washing may need spot bleaching. The best spot bleach to use is titanium sulphate. Apply this bleach with a Q tip. It may be necessary to apply Vaseline on some colored areas to prevent migration of the bleach. Test colors for safety.

BATH BLEACHING

Some dye bleeding may require bath bleaching. The best bleach to use is titanium sulphate. Test the base dye since the bleach may only affect the dye that bled but not the base dye. If your testing determines that the base dye can be affected, dilute the bleach bath and only leave in the garment a few seconds before removing and rinsing.

RED DYES

Red dyes are known to be potential bleeders and should carefully be tested for dye fastness. You can easily test a red dye to drycleaning by wiping an unexposed area of the garment with a cloth damp with volatile dry solvent. To test the dye for solubility to water flush an area of the garment with the steam gun into a cloth. Note how readily the dye transfers. If a dye is fugitive to solvent, it is usually safe to water and vice versa.