Coatings high-viscosity

Solutions of rhamsan have high viscosity at low shear rates and low gum concentrations (90). The rheological properties and suspension capabiUty combined with excellent salt compatibihty, make it useful for several industrial apphcations including agricultural fertilizer suspensions, pigment suspensions, cleaners, and paints and coatings. 

Panel filters may use either viscous or dry filter media. Viscous filters are so called because the filter medium is coated with a tacky liquid of high viscosity (e.g., mineral oil and adhesives) to retain the dust. The filter pad consists of an assembly of coarse fibers (now usually metal, glass, or plastic). Because the fibers are coarse and the media are highlv porous, resistance to air flow is low and high filtration velocities can be used. 

For a number of purposes the unmodified epoxide resins may be considered to have certain disadvantages. These disadvantages include high viscosity, high cost and too great a rigidity for specific applications. The resins are therefore often modified by incorporation of diluents, fillers, and flexibilisers and sometimes, particularly for surface coating applications, blended with other resins. 

The calender was developed over a century ago to produce natural rubber products. With the developments of TPs, these multimillion dollar extremely heavy calender lines started using TPs and more recently process principally much more TP materials. The calender consists essentially of a system of large diameter heated precision rolls whose function is to convert high viscosity plastic melt into film, sheet, or coating substrates. The equipment can be arranged in a number of ways with different combinations available to provide different specific advantages to meet different product requirements. Automatic web-thickness profile process control is used via computer, microprocessor control. 

Increase viscosity, e.g. magnesium oxide in unsaturated polyester resins increases the viscosity so much that a liquid resin becomes a tackfree solid, suitable for making sheet moulding compound (SMC). A relatively high viscosity is also desirable for latex compounds used to coat textiles. 

With the substantial interest in use of aqueous coating systems, an added burden is placed on the atomizing process. This burden results from the relatively high viscosities and surface tensions of aqueous systems. Fortunately, in applications using modified-release coatings, aqueous versions of such coating systems are typically in the form of latexes, or polymer dispersions, which have relatively low viscosities for the solids content of the coating system, and the presence of... 

High Solids Coatings, High solids coatings resemble the technology of solvent-free coatings but the compositions contain ca 70% by volume of solid resin and are modified by reactive diluents, low viscosity multiftinctional resins, or backbone structures other than the bisphenol A moiety. 

Hydroxy propyl methyl cellulose (HPMC).35 HPMC is a partly O-methylated and 0-(2-hydroxypropylated) cellulose available in several grades that vary in viscosity and extent of substitution. It is used widely in pharmaceutical formulations, especially in oral products, as a tablet binder, in film coating, and as controlled release matrix. Soluble in cold water, it forms a viscous colloidal solution. For a 2% aqueous solution (20°C), viscosity can range from 2.4 to 120,000 mPa-s. High-viscosity grades can be used to retard the release of water-soluble drugs from a matrix. 

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