PRINCIPLES OF FABRIC BLEACHING AND DISCOLLING
The whitening process can be part of the washing process. Thus, commercially available detergents contain bleaching chemicals, or they are offered under the name of bleaching / washing agents. However, if the washing results are not satisfactory or if there are visible stains after washing, then the underwear is subjected to an additional whitening treatment. In domestic conditions, among the listed chemicals, hydrogen peroxide and a solution of potassium hypochlorite are used. First, use hydrogen peroxide. Only then, when you don't see the results you want, potassium hypochlorite solution is used. However, at-home whitening with hypochlorite is generally problematic - the greatest possible care is required..
Bleaching is done on yellowed or decayed items of underwear, as well as stained white fabrics. Bleach is necessary to remove the following types of stains: from aniline or from tar products, like for example. blue ink, stale blood stains, grass stains, fruit, coffee, cocoa, stains from copy pencils, lipsticks for lips (in this case, the fatty substance must be removed with a solvent before bleaching), nicotine stains, red wine, mold, ink, urine, etc.. Red ink stains cannot be removed in this way.
Discoloration at home (dye dressing) is important in the case of re-staining. For this purpose, only preparations offered by the trade should be used (e.g.. Braun decolorizers - sulphites), which are better and more convenient to use than pure chemicals. Decolorants are then used, when color stains need to be removed, caused by discoloration, i.e.. dye transfer to another fiber, or larger fruit stains. It is generally preferable to use full cleaning rather than spot cleaning. Most often, a sufficient procedure is to immerse the stained pieces of linen in a bath of diluted decolorizer for some time. Yellowness and mildew stains also disappear in a cold decolorizing bath.
In order to avoid unnecessary failure and loss in bleaching and discoloration, certain basic rules and principles should be followed..
1. First, remove the finishing agent (glue). At home, it can be done by thorough wet washing with detergent. In this way, the sizing is almost completely removed, as well as most of the substances that inhibit moisturizing. Only then is the still damp cloth put into the solution, which, in the case of linen and cotton fabrics, may have a boiling point. However, for wool and natural silk, a summer bath should be prepared, because - as you know - all hot washing processes can cause felting of the fiber. Some types of fibers are not resistant to high temperatures at all. Moreover, the effect of the decolorizing bath is unnecessarily too intense at elevated temperatures. The duration of the treatment depends on the degree of discoloration required. Most often, a few minutes is enough.