High solids

The second type of thin-film evaporator, termed a wiped-film evaporator, introduces feed material on a heated waU of a cylinder. Rotating wiper blades continuously spread the feed along the inner waU of the cylinder to maintain uniformity of thickness and to ensure contact with the heated surface. The volatile components are driven off and coUected on an internal chilled condenser surface. The condensate or distUlate is removed continuously. At the end of the process, the residual becomes dry and heavy and drops to the bottom of the unit for removal. The wiped-film evaporator is best suited for treatment of viscous or high-solids content feed. 

High solids, water, high purity required... 

D. C. Busby and co-workers. Supercritical Fluid Spray Application Technology A Pollution Prevention Technologyfor the Futures PP- 218—239 Proceedings of the 17th Water-Borne and High-Solid Coating Symposiums New Orleans, La., 1990. 

However, this difference would not seem to be large enough to account for the very large differences in solvent losses that have been reported. Another factor may be that high solids coatings may reach a stage where solvent loss is controUed by diffusion rate much eadier than is the case in low solids coatings (8,43). 

A. E. Cassel and B. P. Johnson, Evaluation of Devices for Producing High Solids Sludge Cake, NTIS Report No. PB80-111503, National Technical Information Service, Washington, D.C., 1980. 

High Solids Costings. High soHds coatings resemble the technology of solvent-free coatings but the compositions contain ca 70% by volume of soHd resin and are modified by reactive diluents, low viscosity multifunctional resins, or backbone stmctures other than the bisphenol A moiety. 

Heavy-gravity particles have a relatively faster setthng velocity than light-gravity parficles of the same size. High solids concentration increases the viscosity and density of the fluid medium. 

Size of solid particles - Lxiw solids concentrations (less than 10% average) classified by size and material, generally exhibit no adverse affect to pump efficiency. However, the discharge configuration of the pump must be sufficiently large to prevent obstructions. For example, sanitary and wastewater pumps that handle high solids. 

In addition, with high solid content of the cooling water and at high flow velocities, severe corrosive conditions exist which continuously destroy surface films. Cathodic protection alone is not sufficient. Additional measures must be undertaken to promote the formation of a surface film. This is possible with iron anodes because the anodically produced hydrated iron oxide promotes surface film formation on copper. 

Monte, S.J., Proc. 25th Int. Symp. Waterborne, High-Solids, Powder Coating, 190 (1998). 

SBR latices are high-solids dispersions of rubber particles in water, the viscosity and rheology of which are, in general, independent of the polymer properties, unlike solutions. They offer a wide range of molecular weight and glass transition temperature. Three classes of SBR latices are available in the market. 

Neoprene 654. It is a high-solids, low-viscosity latex containing a very low gel polymer. It offers good tack and flexibility. 

Fillers. Fillers are not commonly added to CR adhesives. Calcium carbonate or clay can be primarily added to reduce cost in high-solids CR mastics. Maximum bond strength is obtained using fillers with low particle size (lower than 5 [jim) and intermediate oil absorption (30 g/100 g filler). In general, fillers reduce the specific adhesion and cohesion strength of adhesive films. Although polychloroprene is inherently flame retardant, aluminium trihydrate, zinc borate, antimony trioxide or... 

Chandalia, K. et al.. In Storey, R. and Thames, S. (Eds.), Proceedings of 28th International Waterborne, High-Solids and Powder Coating Symposium. New Orleans, LA, 2001, p. 77. Woods, G., The ICI Polyurethanes Book. Wiley, New York, NY, 1987. 

Fig. 3. RSST results on some typical production novolacs. The solids on these materials are 74, 70, and 62%, respectively. Note that the reaction does not become initiated significantly below 70 C and that the high solids system is capable of self-heating rates as high as 5500°C/min under these conditions. (Chart courtesy of Borden Chemical and Bill Burleigh.)...

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