Impingement mixing Properties

Tamir, A. and Luzzatto, K. (1985). Solid-solid and gas-gas mixing properties of a new two impinging stream mixer. AIChE J., 31 781-787. 

P. Kolodziej, C. W. Macosko, and W. E. Ranz, "The Influence of Impingment Mixing and Stiration Thickness Distribution and Properties in Fast Polyurethane Polymerization". J. Polymer Eng s and Sci., 22 (6) April 1982. 

The compatibility of a colorant is assessed not only on the basis of the ease with which it can be mixed with the base resin to form a homogeneous mass but also on the requirement that it neither degrades nor is degraded by the resin. In relation to product functional properties, incompatibihty of a colorant can affect mechanical properties, flame retardancy, weatherability, chemical and ultraviolet resistance, and heat stability of a resin through interaction of the colorant with the resin and its additives. Flame retardancy, for example, may impinge directly on the performance of a colorant. Pressure to produce materials with lower levels of toxic combustion products can involve organic fire retardant additives that interact with the colorant either to negate the effect of the additives or affect the color. 

The processing requirements for RIM are very stringent (a) the reactive streams must be effectively mixed by impingement (b) the system must not produce molding defects due to turbulence or advance polymerization (c) completion or near-completion of the polymerization must be achieved in an economically acceptable time and without excessive exotherms and (d) the reaction must be free of undesirable by-products. To date, very few polymerization systems have been used commercially with RIM. Polyurethanes account for over 90% of RIM materials produced. Other RIM systems include the anionic polymerization of caprolactam to produce nylon-6, and the ring opening polymerization of dicyclopen tadiene. Fillers are often incorporated into RIM formulations to lower raw material costs and to improve certain properties such as stiffness. 

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