Blend application

Ribbon blenders are essentially self-contained mixers. They are employed in a variety of solid-liquid, solid-solid, and liquid-liquid blending applications in the chemical process industries. Examples include plastics, pigments, pharmaceuticals, specialty chemicals, confectionary. 

The correct number of Kenies Mixer models for blending applications... 

Problems of segregation, no-flow/erratic flow, flooding, etc, must be minimized if not eliminated, therefore containers designed for mass flow as opposed to funnel flow are preferred. The BINSERT has significant advantages over standard mass flow designs, which are particularly useful in tumble blending applications (Fig. 17) (18). 

Powders are dissolved either directly in the main mix tank or premix tank or indirectly using a vortex-type mixer (Figure 8.1) where powder is dropped into the vortex of a horizontally mounted pump head recirculating the fluid from and to the batch tank. Some specialised versions of this mixer can handle very viscous blending applications (50,000 cP or more). 

Fontaras G, Kousoulidou M, Karavalakis G, Tzamkiozis Th, Pistikopoulos P, Ntziachristos L, Stoumas S, Samaras Z (2010) Effects of low concentration biodiesel blend application on modem passenger cars. Part 1 feedstock impact on regulated pollutants, fuel consumption and particle emissions. Environ Pollut 158 1451-1460... 

Mixer Rankings for Turbulent-Flow Blending Applications... 

More than 4.5 million metric t of solvents is used in the United States annually, and it has been suggested by industry experts that ethyl lactate could replace conventional solvents in more than 80% of these applications (34). Vertec Biosolvents Inc. is currently using ethyl lactate in soy oil-solvent blends. Applications targeted by Vertec Biosolvents include conventional solvents that are under environmental scrutiny such as methylene chloride, methyl ethyl ketone, and N-methyl pyrrolidone (36). Table 3 lists the selling prices of some common solvents. 

To design the Kenics Mixer for a blending application, the procedure is as follows ... 

Silicates. Both sodium and potassium silicate solids or solutions have valued functionality including emulsification, buffering, deflocculation, and antiredeposition ability. Silicates also provide corrosion protection to metal parts in washing machines, as well as to the surfaces of china patterns and metal utensils in automatic dishwashers. Silicates are manufactured in liquid, crystalline, or powdered forms and with different degrees of alkalinity. The alkalinity of the silicate provides buffering capacity in the presence of acidic soils and enhances the sequestration ability of the builder system in the formulation. The sili-cate/alkali ratios of the silicates are selected by the formulator to meet specific product requirements. Silicate ratios of 1/1 are commonly used in dry blending applications with silicate ratios of 2/1 and higher commonly used in laundry and autodish applications. 

The finish is resistant to laundering and dry cleaning and is suitable for cotton, wool, synthetics, and blends. Application should always be from a master batch to assure uniformity of treatment. 

Chemical nature Buffered metallic complex blend Application ... 

Methane forms azeotropes with many hydrocarbons. For example, methane and n-butane at 32°F and 2660 psig form an azeotrope with 92.9 mol% methane. Azeotropes are ideal for fuel blend applications because the composition remains essentially constant as the fuel is being used and the tank is being emptied. Little has been done to date to identify the optimal temperature and pressure conditions for the formation of azeotropes for the various hydrocarbons and for commercial gasoline and diesel compositions. 

Much development work has produced powder coatings for decorative niche markets. They are now available in a wide range of gloss levels, colors, and specialized surface effects such as metallics, pearles-cent, fluorescent, antique, hammertone, textured, wrinkled, and clearcoats. Metallic powder coatings have presented an application challenge, because some types of metallics are dry blended. Application equipment manufacturers have learnt how to apply these challenging materials. ° ... 

Vinuesa, J.-F. Mirabel, P. Pnche, J.-L. Air quality effects of using reformulated and oxygenated gasoline fuel blends application to the Strasbourg area (F). Atmos. Environ. 2003, 27, 1757-1774. 

These determine the difficulty of the mixing application, as illustrated in Figure 9.41. The wider the viscosity difference between the component streams, the more difficult is the blending application. The most difficult application is the addition of a small, low-viscosity stream into a large, high-viscosity stream in laminar flow. For example, Tables 9.20(a) and 9.20(b) show effects... 

The variation coefficient, o/I, is used in blending applications to characterize the homogeneity in a static mixer. Equation (9.65) defines <3lx ... 

Both polymers have excellent hydrolytic stability—one because it is a polyether and the other because it sterically hinders hydrolytic action. The polycarbonate, like the polyether, is reported to be compatible with polystyrene. The high T would suggest dimensional stability and utility at very high temperatures, but thermal-oxidative limitations will probably favor blend applications at moderately high continuous-use temperatures. 

Table 6.4. Selected patents in latex blend applications... 

Insufficient chemical resistance of a blend at times leads to its rejection for use in an aggressive chemical environment, although it possesses an excellent combination of mechanical properties. Thus chemical and solvent effects on polymer blends are important factors that frequently determine blends applicability. Attention has been given to chemical resistance of blends starting from the fundamental concept of the solubility parameters. Apart from the chemical and environmental restrictions, thermal resistance of a polymer blend is often a major criterion for its applicability. Thus, the thermal conductivity, heat capacity and heat deflection temperature of polymeric materials are discussed in separate sections. 

One of the growing areas for PAB blend applications under the hood is in electrical and electronic connectors and systems for power distribution and control. Such applications often require low melt viscosity at injection molding temperatures to fill the intricate tooling that may be designed for up to hundreds of individual electrical connections. Practical toughness is required for snap-fit of the connections. Furthermore, glass-reinforcement of these PAB s may be required to improve modulus and dimensional stability. Typical blends suitable for these applications include PBT/PC, PA/PPE and PPS/PEI. 

Blending provides a convenient way of combining the mechanical, physical, or thermal properties of more than one material. One example is the blend of ABS and PVC. The ABS contributes high heat-distortion temperature, toughness, and easy moldability, while the PVC imparts weatherability and flame retardance, as well as reducing the cost of the blend. Applications of the blend include automotive interior trim, luggage shells, and canoes. 

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