Manufacturing methods processes

The manufacturing methods/process simulation include the following steps (see individual MFM [manufacturing formula and method] for media hll run) ... 

Among famous methods of BR chlorination by molecular chlorine or chlorine-containing organic compounds in solution, water dispersion and liquid melt [27,143,176,262, 266] chlorination of BR by molecular chlorine in solution is the most manufacturable method. Process consists of several power-consuming stages [27,176,177] ... 

Table 1.5 Synthetic membrane manufacturing methods Process Materials...

The manufacture of MDF, with a few exceptions, dupHcates the manufacture methods for dry-process hardboard, described at length hereia. One exception to it is that most MDF is made ia the medium-density range, 640—800 kg/m although small amounts are made at lower or higher densities. Second, the vast majority of MDF is made with UF resia adhesives with resia requhemeats ia the 7—11% range, and wax is usually added at the 0.50—0.75% level. A small amount of exterior-grade MDF is made with isocyanate resia. 

Gra.de A. Types I and II both represent the requirements of the USP XX (26). The USP tests arose from original formal oxygen specifications made necessary by the low purity and certain contaminants, particularly CO and CO2, contributed by early chemical and cryogenic manufacturing methods. Containers marked Oxygen-USP must also indicate whether or not the gas has been produced by the air Hquefaction process (see also Fine chemicals). 

Manufacture and Processing. Until World War II, phthaUc acid and, later, phthaUc anhydride, were manufactured primarily by Hquid-phase oxidation of suitable feedstocks. The favored method was BASF s oxidation of naphthalene [91-20-3] by sulfuric acid ia the presence of mercury salts to form the anhydride. This process was patented ia 1896. During World War I, a process to make phthaUc anhydride by the oxidation of naphthalene ia the vapor phase over a vanadium and molybdenum oxide catalyst was developed ia the United States (5). Essentially the same process was developed iadependendy ia Germany, with U.S. patents being granted ia 1930 and 1934 (6,7). 

Manufacturing methods to assure product consistency and the safety of personnel exposed to the dmg or process intermediates. 

Batch Saponification. Batch saponification, the oldest PVA manufacturing method (252), is mainly used in the 1990s for the production of specialty products. The process uses a kneader in which the hydrolysis, washing, and drying operations are performed. This is the simplest method of saponification, but the production rates are low, and producing the product quaUty needed by many end uses is difficult. 

Sihcon carbide is also a prime candidate material for high temperature fibers (qv). These fibers are produced by three main approaches polymer pyrolysis, chemical vapor deposition (CVD), and sintering. Whereas fiber from the former two approaches are already available as commercial products, the sintered SiC fiber is still under development. Because of its relatively simple process, the sintered a-SiC fiber approach offers the potential of high performance and extreme temperature stabiUty at a relatively low cost. A comparison of the manufacturing methods and properties of various SiC fibers is presented in Table 4 (121,122). 

Water-Soluble Trivalent Chromium Compounds. Most water-soluble Cr(III) compounds are produced from the reduction of sodium dichromate or chromic acid solutions. This route is less expensive than dissolving pure chromium metal, it uses high quaHty raw materials that are readily available, and there is more processing fiexibiHty. Finished products from this manufacturing method are marketed as crystals, powders, and Hquid concentrates. 

After the second World War, German firms manufacturing indigotin faced serious competition from Knglish and American dyestuff companies. To counteract this, the Germans developed continuous operations for manufacturing the dye. However, because of the complexity of the equipment and the operations (126), the batch process is still the preferred manufacturing method. 

Utility Patents. Utility patents are granted to individuals only who have invented or discovered any new and useful method, process, machine, manufacture, or matter composition. These patents must be useful to society (have utility). A utility patent has a total time limit for exclusive use by the inventor of 17 years. 

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