An additional problem is caused by solvents that evaporate too quickly, causing, that some of the dirt-forming substances can bind strongly to the fibre. Otto Wachter even talks about inclusion, tj. incorporating small amounts of substances into the intermolecular structure of the fibres, e.g.. wool. Unfortunately, after removing the fatty substances, dirt usually remains and only wet washing changes the situation. So you can say, that in the case of ordinary dirt, wet cleaning gives better results. Organic solvents do not have a greater effect on inorganic impurities and only water dissolves and rinses them. You can also not use organic solvents to clean fabrics dyed or painted with paints with an oil or resin binder. In addition, organic solvents should not be used to clean the so-called. wet fabrics, found during archaeological excavations in the ground. Rapid removal of water would cause deformation and damage to fabrics. The routine operation of dry cleaning begins with the use of low performance solvents (after testing the color fastness).
The most common solvents used for this purpose are:: trichlorethylene, tetrachlorethylene, carbon tetrachloride and gasoline. Neither of these measures is perfect. Trichlorethylene, commonly known as "tri” however it is non-flammable, easily volatile and non-corrosive to metals, however, it is poisonous. It may be partially decomposed by prolonged exposure to light, hydrogen chloride is released, very harmful to fabrics. For this reason, "three” is used in the presence of ammonia. You can three” protect against decomposition by adding a stabilizer, np., phenol. "tri" may be too aggressive for cleaning vintage fabrics. After unfolding "tri” has a strong degreasing effect on the product, until its damage. Fibers devoid of the original amount of fat are damaged particularly quickly. tetrachlorethylene (perchloroetylen) is a very good solvent of fatty substances (incombustible, medium volatile and not harmful to fibers and dyes), however, it can also be too aggressive to clean some old ones, vintage fabrics. Carbon tetrachloride, solvent with good cleaning properties, it is highly poisonous, negatively affects most metals in the presence of water. Decomposes in the presence of water into carbon dioxide and hydrochloric acid, it also attacks the fibres, so it is used less and less. Gasoline is used in several varieties, with different specific gravity and boiling point, considering it a good solvent for fats and oils, but it is a flammable liquid, and its vapors are capable of creating explosive mixtures with air.
