Compound cost

The choice of process is generally based on economic issues such as volume of seals to be produced elastomeric compound, cost and waste and product design. 

Mineral oils also known as extender oils comprise of a wide range of minimum 1000 different chemical components (Figure 32.6) and are used extensively for reduction of compound costs and improved processing behaviors.They are also used as plastisizers for improved low temperature properties and improved rubber elasticity. Basically they are a mixture of aromatic, naphthanic, paraffinic, and polycyclic aromatic (PCA) materials. Mostly, 75% of extender oils are used in the tread, subtread, and shoulder 10%-15% in the sidewall approximately 5% in the inner Uner and less than 10% in the remaining parts for a typical PCR tire. In total, one passanger tire can contain up to 700 g of oil. 

Nandanan et al. [35] reported the utilization of linseed oil as an MFA in nitrile rubber vulcanizates. Linseed oil not only acted as a plasticizer but also as the fatty acid component of the activator in the NBR vulcanizates. Use of linseed oil gave appreciable increase in properties like tensile strength, tear resistance, etc. while the viscosity of the compound was marginally lower than that of the control compound (which used di-octyl phthalate as the plasticizer). The vulcanizates containing linseed oil also exhibited increased cure rate as well as reduced leachability compared to the control at a dosage of 2-5 phr. This loading was seen to replace 6 phr DOP and 2 phr stearic acid in conventional NBR vulcanizates thereby reducing compound costs. 

Aid in the uniform dispersion of additives. Make powdered solids (e.g. particulate fillers with high energy and hydrophilic surface) more compatible with polymers by coating their surfaces with an adsorbed layer of surfactant in the form of a dispersant. Surface coating reduces the surface energy of fillers, reduces polymer/filler interaction and assists dispersion. Filler coatings increase compound cost. Fatty acids, metal soaps, waxes and fatty alcohols are used as dispersants commonly in concentrations from 2 to 5 wt %. 

Mueller and Stickney at Battelle revealed very substantial compounding costs for protection against photochemical oxidants. Table 13-14 summarizes the results of an analysis based on responses to a questionnaire. These costs include the introduction of such ozone-resistant polymers as butyl, neoprene, EPDM, Hypalon, and polysulfide. Fair... 

Table 2 displays a cost estimate prepared for the U.S. Army Environmental Center (USAEC). This estimate assumed that the Enviro-Blend compound cost 340 per ton and was applied at a ratio of 3% by weight. Disposal costs of 14 per ton were used (D22759S, p. 14). 

First introduced industrially in the 1930s, thermoplastic polymers are today produced and consumed in vast quantities and play a major role in many aspects of our everyday lives. It is estimated that over 16 million tons were consumed in Western Europe alone in 1991 [1]. Mineral fillers have, since the beginning, made an important contribution to the spectacular growth of thermoplastic polymers. The addition of mineral materials was initially seen mainly as a means of extending or reducing the compound cost but, as the relative cost of the polymers decreased, this became less important and attention was more and more focused on the property improvements that could be achieved. 

The need to minimise production costs and hence the selling price of mineral fillers is a dominant theme running through the technology. Although compound cost reduction was one of the principal reasons for using fillers in the past, this is of less importance now, due to the fall in the cost of the commodity thermoplastics. Indeed, the cost in use of fillers (taking into account volume costs and the cost of incorporation) can now lead to a rise in overall compound costs and it is often the minimisation of this cost increase that has become important. 

In addition to the raw material cost, one also has to take into account compounding costs, the cost of any coupling agent or surface modifier that is not already present on the filler and the cost of additional stabilisers that might be re-... 

The point of the foregoing was to illustrate the importance of considering all aspects of formulation changes - energy savings may or may not be real, and the extra compound cost, plus possible adverse affects on overall performance must also be considered. 

However, a perfumer needs to justify the complexity of a formula and the use of bases against the demands of his or her company in keeping compounding costs to a minimum. To include in a formula half a dozen or more bases, all of which contain many of the same materials is quite unjustified from the point of view of production. The perfumer should try, wherever possible, to use existing bases rather than trying to work only with bases of his or her own making. Much... 

A material added to a polymer in order to reduce compound cost and/or, to improve processing behavior and/or, to modify product properties... 

There are several approaches to evaluation of the blend economy. Eor example, the cost of a blend equals the weight-average of material cost, plus the compounding cost per unit mass, e.g.,... 

Fillers increase the strength of the compound and impart useful rheological properties while reducing the compound cost. Table III and FIGURE 3 (using data based on LP-32 polymer) illustrate typical effects on the properties of filled compounds. 

A final word in this short summary of impact modification concerns the amount of imagination compounders and polymer scientists continue to invest in the development of rubber-modified compoimds. Efforts are being made to decrease their compounding costs, to enhance their paintability, and to formulate them to replace more competing materials such as ABS, thermoset rubber, and PVC—thereby allowing more recyclable "aU-olefin" automotive interiors, for example. Recent efforts have even been made to incorporate ground vehicle tire rubber or other "ultrafine rubber particles into PP to create vulcanized elastomeric thermoplastics that cost less than half as much as standard TPVs. Similar concepts will continue to push impact-modified POs into new applications [7-26, 7-27, 7-28]. 

Bunsen, Robert Wilhelm (1811-99) German chemist, who held professorships at Kassel, Marburg, and Heidelberg. His early researches on arsenic-containing compounds cost him an eye in an explosion. He then turned to gas analysis and spectroscopy, enabling him and Kirchhoff to discover the elements caesium (1860) and rubidium (1861). He also popularized the use of the Bunsen burner. 

In summary, the cost of production of secondary metabolites is difficult to estimate. The physiological cost of production varies for different secondary compounds costs for compounds containing limiting elements such as nitrogen may be especially sensitive to environmental fluctuations in these nutrients. Physiological cost and evolutionary success are not linked in linear fashion for evolutionary considerations, some estimate of cost linked to fitness is essential. 

Increased output Improved physical properties Higher-impact strength Reduced reject rates Faster start-up Elimination of plate-out Compound cost reduction Enhanced gelation... 

The non-fluid, non-critical containment requirements of these products mean that polymer compound costs and production costs can be minimised. Underground cable and telecommunication ducts are produced as variants of minimum mechanical specification drainage pipes. Where high flexibility is required, to allow cabling around tortuous paths in equipment and buildings, then corrugated pipes are used. Since there is no fluid flow... 

Materials modification, such as with fibers or with fillers, is extensively adopted with thermosetting plastics, and now with engineering plastics, so as to obtain a desirable combination of properties. It is not done simply to save money as often a molding, made from a filled compound, is the same price as one made from the unfilled plastics material. This is because of the high density of most fillers and because of the high compounding costs. Many of the fillers used are fibrous fillers as the use of such materials improves properties such as modulus. 

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