Dry-cleaning solvents

Dry bead process Dry-cell batteries Dry chemistry Dry-cleaning Dry cleaning fastness Dry-cleaning fluid Dry-cleaning solvent Dryers... 

The main uses of petroleum naphtha fall into the general areas of solvents (diluents) for paints, etc, dry-cleaning solvents, solvents for cutback asphalt, solvents in mbber industry, and solvents for industrial extraction processes. Turpentine, the older, more conventional solvent for paints, has been almost completely replaced by the cheaper and more abundant petroleum naphtha. 

Before hydraulic lines or fittings are disconnected, the affected area should be cleaned with an approved dry-cleaning solvent. 

After the parts have been cleaned in dry-cleaning solvent, they should be dried thoroughly with clean, low-lint cloths and lubricated with the recommended preservative or hydraulic liquid before assembly. Note Only clean, low-lint type 11 or 1 cloths as appropriate should be used to wipe or dry component parts. 

Tetrachloromethane, CC14, which is now known to be carcinogenic, was once used as a dry-cleaning solvent. The enthalpy of vaporization of CC14 is 33.05 kj-mol 1 and its vapor pressure at 57.8°C is 405 Torr. What is the vapor pressure of tetrachloromethane at 25.0°C ... 

Dodecylpyridinium iodide-reversed micelles trapping chlorophyll a have been suggested as interesting photochemical model systems [22] and water/AOT/chloroethylene systems as peculiar dry-cleaning solvents [64]. 

Distillation of tetrachloroethylene (formerly a dry-cleaning solvent) in new galvanised steel equipment produces traces of dichloroacetylene. This is toxic and may cause ill-health in those exposed. Should the acetylene chance to be concentrated (as in the sub-entry above), it is also very explosive. The galvanised metal becomes passivated in a few days and the effect was not found with other steels. 

Another challenge is to develop methods to replace the volatile organic solvents that are used in many industrial procedures. One choice is water as a solvent it is easily repurified, and has a harmless vapor. Another choice is supercritical carbon dioxide, a good solvent for many organic substances. It is not as innocuous as is water, but carbon dioxide can be easily recovered and reused. It is currently used to remove caffeine from coffee, and is being developed as a dry-cleaning solvent to replace organic solvents (Chapter 9). 

I now shall present a summary of an application of decision analysis to a specific chemical, perchloroethylene (PCE), a widely used dry cleaning solvent (also called tetrachloroethylene). Full details of this application are presented in an EPA report (5). Perchloroethylene was selected for us by the staff of the EPA Office of Toxic Substances as representative of chemicals on which EPA needed to make an unreasonable risk determination under TSCA. Our analysis was carried out as an exercise in methodology development and not to support any specific regulatory activities by EPA concerning perchloroethylene. 

Exposure Assessment. Since perchloroethylene is used as a dry cleaning solvent and PCE vapor is easily monitored, estimates of PCE exposure are relatively straightforward to make from existing data in the literature. Table II summarizes the results. Based on NIOSH data (17), machine operators are exposed to an average of about 30 ppm of PCE vapor during the working day, equivalent to a... 

The textiles printing industry, however, uses P.O.34 to an appreciable extent. The pigment provides average lightfastness (at 1/3 SD, it equals step 5-6 on the Blue Scale) its dry cleaning solvent resistance is excellent, and it withstands ex-... 

Resistant to many types of chemicals, such as detergents, gasoline, and dry-cleaning solvents. 

Stoddard solvent is a petroleum distillate widely used as a dry-cleaning solvent and as a general cleaner and degreaser. It may also be used as paint thinner, as a solvent in some types of photocopier toners, in some types of printing inks, and in some adhesives. Stoddard solvent is considered to be a form of mineral spirits, white spirits, and naphtha however, not all forms of mineral spirits, white spirits, and naphtha are considered to be Stoddard solvent. 

Uses Dry cleaning solvent for nitrocellulose, cellulose acetate, resins, oil, grease, albumin perfume fixative coating compositions for paper, cloth, leather lacquers. 

Chlorinated ethanes and ethylenes comprise ethyl chloride, ethylene dichloride (1,2 dichloroethane), vinyl chloride, trichloroethylene (TCE), perchloroethylene (RCE), and several CFCs. Some of the major uses of these compounds are as degreasing agents, dry-cleaning solvents, building blocks for manufacturing of polymers (e.g., RVC, ethyl cellulose), and raw material for the production of tetraethyl lead and CECs. We discuss ethylene dichloride, trichloroethylene, and perchloroethylene as examples of this group. 

What is mass (or chemical) transport It is the transport of a solute (the dissolved chemical) in a solvent (everything else). The solute is the dissolvee and the solvent is the dissolver. There are liquids that are generally classified as solvents because they typically play that role in industry. Some examples would be degreasing and dry cleaning solvents, such as trichloroethylene. In environmental applications, these solvents are the solutes, and water or air is usually the solvent. In fact, when neither water nor air is the solvent, the general term nonaqueous phase liquid is applied. A nonaqueous phase liquid is defined as a liquid that is not water, which could be composed of any number of compounds. 

By using Aerosol OT-100% Surfactant in dry cleaning solvent at a concentration of ca. 0.1 oz./gal. the soaps used as aids in watei—soluble stain removal can be replaced in the dry cleaning industry. In contrast to many soaps, Aerosol OT does not oxidize with consequent development of undesirabls odor upon aging. 

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