POLYMERS
...leaning such as those using chlorine. Safe and thoroughly calculated wet laundering would be required. Usage of harmless and effective oxidizing and reducing agents would become necessary for stains that cannot be removed by detergents. Practical training on bleaching by oxidation and reduction as a new cleaning technology should be carried out, as well as development of further bleaching technology which does not cause degradation of materials. Oxidizing and reducing agents such as chlorinated isocyanuric acid and aminoimino-methanesulfinic acid should also be brought into view. Practical trials are anticipated. Trouble, such as bleeding of patterned items or partial exudation of colors, is repeatedly found when garments are returned from dry cleaner's. Many are items that require laundering or washing in water, cleaners are blamed for such trouble, undetected when handed over. But then with tumble-dried items, somehow, bleeding rarely occurs. In most cases, bleeding is caused when a chemical bonding breaks off between reactive dyestuff and cellulosic fiber, which is generally known as 'acid hydrolysis' among experts. In short, acid substances resolve the bonding of dye and fiber and not the dye itself, thereby producing staining. Often, it involves past exposure to the rain when being worn or hung up to dry. The rain, regarded as acidic nowadays, contains sources of air pollution such as sulfur dioxide, which in the air turns into sulfuric acid, or nitrogen oxides that become nitric acid. The acidity of a rain-soaked garment is not so extremely high, however, highly-concentrated acid substances are produced as it dries, causing acid hydrolysis on reactive-dyed items. Such hydrolysed substances often have a tendency to migrate along with water in fiber, which is how bleeding occurs when garments are hung up to dry. As migration is conspicuously found in more easily-dried areas, staining trouble b...