Specifications, product

Most of the engineering plastics faithfully reproduce the mold configuration, and when the processing parameters are appropriately controlled they will repeat with excellent accuracy. 

We see plastic gears and other precision parts made of acetal, nylon, polycarbonate, and Noryl whose tooth contour and other precision areas are made with a limit of 0.0002 in. and the spacing of the teeth is uniform to meet the most exacting requirements. 

Generally, if we approach tolerances according to their purposes a) functional requirements, such as running fit, sliding fit, gear tooth contour, etc. b) assembly requirements— that is, to accommodate parts with their own tolerances and c) matching parts for appearance or utility, we should come up with feasible tolerances that will be reasonable and useful. This will be more productive than trying to apply tolerances strictly on a dimensional basis. 

Tolerances should be indicated only where they are needed, carefully analyzed for their magnitude, and of proven usefulness. It is important to determine if the tolerances shown are realistic for the specified plastic and process. The designer should recognize that extreme accuracy of dimensions is expensive and, in some cases, impossible to hold in processing. 

Adaptation of metal tolerances to plastics is not advisable. The reaction of plastics to 

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In practice, there is likely to be a trace of decane in the reactor eflfluent. However, this should not be a problem, since it can either be recycled with the unreacted chlorine or leave with the product, monochlorodecane (providing it can still meet product specifications). 

Finished product specifications and future constraints for Europe. 

The products could be classified as a function of various criteria physical properties (in particular, volatility), the way they are created (primary distillation or conversion). Nevertheless, the classification most relevant to this discussion is linked to the end product use LPG, premium gasoline, kerosene and diesel oil, medium and heavy fuels, specialty products like solvents, lubricants, and asphalts. Indeed, the product specifications are generally related to the end use. Traditionally, they have to do with specific properties octane number for premium gasoline, cetane number for diesel oil as well as overall physical properties such as density, distillation curves and viscosity. 

Nevertheless, we are witnessing most recently an important development in petroleum product specifications regarding two main factors ... 

Section 10.1 will consider the physical processes which oil and gas (and unwanted fluids) from the wellhead must go through to reach product specifications. These processes will include gas-liquid separation, liquid-liquid separation, drying of gas. 

The end product specification of a process may be defined by a customer (e.g. gas quality), by transport requirements (e.g. pipeline corrosion protection), or by storage considerations (e.g. pour point). Product specifications normally do not change, and one may be expected to deliver within narrow tolerances, though specification can be subject to negotiation with the customer, for example In gas contracts. 

Typical product specification for the oil, gas and water would include value for the following parameters ... 

The following table provides some quantitative values for typical product specifications. 

In the laboratory or process research section a laboratory procedure for a fine chemical is worked out. The resulting process description provides the necessary data for the determination of preliminary product specifications, the manufacture of semicommercial quantities in the pilot plant, the assessment of the ecological impact, an estimation of the manufacturing cost in an industrial-scale plant, and the vaHdation of the process and determination of raw material specifications. 

Useful materials incorporating fire-retardant additives are not always straightforward to produce. Loadings of 10% are common, and far higher levels of flame retardants are used in some formulations. These concentrations can have a negative effect on the properties and functions for which the materials were originally intended. Product-specific trade-offs are generally necessary between functionaUty, processibiUty, fire resistance, and cost. 

Anhydrous hydrogen fluoride is also available in cylinders, and aqueous hydrogen fluoride, either 50% or 70%, is also shipped in polyethylene bottles and carboys. Typical product specifications and analysis methods are given in Table 4. 

A.queous and yinhjdrous Hydrogen Fluoride product specifications, AUied-Signal Inc., Morristown, N.J., 1991. 

The properties that are achieved in commercial stmctural foams (density >0.3 g/cm ) are shown in Table 3. Because these values depend on several stmctural and process variables, they can be used only as general guidelines of mechanical properties from these products. Specific properties must be deterrnined on the particular part to be produced. A good engineering guide has been pubHshed (103). 

Formaldehyde is sold in aqueous solutions with concentrations ranging from 25 to 56 wt % HCHO. Product specifications for typical grades (18,117—119)... 

Bismuth citrate can be used only for coloring scalp hair such that the amount of bismuth citrate does not exceed 0.5% weight/volume of the product. Specific restrictions prohibit the use of bismuth citrate for coloring eyelashes, eyebrows, or hair on parts of the body other than the scalp they also iadicate label specifications. 

Purification of Carbide Acetylene. The purity of carbide acetylene depends largely on the quaUty of carbide employed and, to a much lesser degree, on the type of generator and its operation. Carbide quahty in turn is affected by the impurities in the raw materials used in carbide production, specifically, the purity of the metallurgical coke and the limestone from which the lime is produced. The nature and amounts of impurities in carbide acetylene are shown in Table 4. 

The fermentation-derived food-grade product is sold in 50, 80, and 88% concentrations the other grades are available in 50 and 88% concentrations. The food-grade product meets the Vood Chemicals Codex III and the pharmaceutical grade meets the FCC and the United States Pharmacopoeia XK specifications (7). Other lactic acid derivatives such as salts and esters are also available in weU-estabhshed product specifications. Standard analytical methods such as titration and Hquid chromatography can be used to determine lactic acid, and other gravimetric and specific tests are used to detect impurities for the product specifications. A standard titration method neutralizes the acid with sodium hydroxide and then back-titrates the acid. An older standard quantitative method for determination of lactic acid was based on oxidation by potassium permanganate to acetaldehyde, which is absorbed in sodium bisulfite and titrated iodometricaHy. 

Although steeping cycles vary from maltster to maltster, they can be classified as a variation or combination of one of three processes, indicated A, B, and C. The choice of steeping procedures depends on equipment limitations, process or product specifications, and company tradition. 

Of the three worldwide manufacturers of poly(ethylene oxide) resins. Union Carbide Corp. offers the broadest range of products. The primary quaUty control measure for these resins is the concentrated aqueous solution viscosity, which is related to molecular weight. Specifications for Polyox are summarized in Table 4. Additional product specifications frequendy include moisture content, particle size distribution, and residual catalyst by-product level. 

Table 4 gives information on significant uses and Table 5 provides manufactuting data on various alkylamiaes for 1988, from capacity announcements ia Chemical Week, Hydrocarbon Processing, and European ChemicalNem. Table 6 gives general sales specifications and the U.S. Hst price (1991). More detaHed product Specifications are avaHable from the various iadicated manufacturers. 

Product Specifications (l-6A5-lf, l-6B5-l.lb, and l-6E5-lh) Union Carbide Chemicals and Plastics Corp., Danbury, Coim., Jan. 20, 1989. 

Table 4. Product Specification for Chemical-Grade Propylene...

Finally, the laboratory expends significant effort communicating results to both internal and external customers. Production, quaUty assurance, and purchasing all have various information needs ranging from the simple pass /fail decisions to statistical summaries of the data and suppHer product quahty. Customers expect to receive lot analyses in the form of a COA and often also want their own product-specific information on the document as well. This information can automatically be appHed to the COA if entered into the LIMS. Often, a quaUty-conscious customer wants information about the product in the form of process capabiUty or control charts. Using LIMS, these charts can be provided on demand. 

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