Coatings continued types

Exxate solvents are efficient coalescent aids for water-borne latex coatings. Water is used in water-borne coatings as a diluent or latent solvent in combination with an active solvent. A latex emulsion (individual resin particles) affords a continuous protective film after the resin particles coalesce during the drying process. Successful film formation requires a solvent coalescent aid that softens the resin particles allowing individual particles to form a continuous film. The coalescent solvent must remain in the film until after the water evaporates from the coating. The type of latex often determines which coalescent solvents affords the best film properties. 

A steady-state rocket-type combustion spray unit has been developed, called high velocity oxy fuel (HVOF), that creates a steady state, continuous, supersonic spray stream (1.2—3 mm dia) resembling a rocket motor exhaust. The portable device injects and accelerates the particles inside a barrel (rocket nozzle). It produces coating quaHty and particle velocities equal to the D-gun at 5—10 times the spray rate with significantly reduced coating costs. 

The primary substrates or support iaclude many types of paper and paperboard, polymer films such as polyethylene terephthalate, metal foils, woven and nonwoven fabrics, fibers, and metal cods. Although the coating process is better suited to continuous webs than to short iadividual sheets, it does work very well for intermittent coating, such as ia the printing process. In general, there is an ideal coater arrangement for any given product. 

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