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US 4,675,140 AGranted
Method for coating particles or liquid droplets
AssigneeWashington University Technology Associates
InventorsRobert E. Sparks, Norbert S. Mason
Life of this patent
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AssigneeWashington University Technology Associates
InventorsRobert E. Sparks, Norbert S. Mason
Estimating the term…
Solid particles or viscous liquid droplets of core material are encapsulated in a coating material largely as single particles with a single coherent coating, by feeding a suspension of the two materials onto a rotating surface. The suspension is centrifugally dispersed by the rotating surface into relatively large coated particles and relatively small droplets of coating material. Only the size of the droplets of unused coating corresponds to the droplets formed from atomization of the liquid coating material. The size of the coated particles depends on the size of the uncoated particles and is much less dependent upon the atomization characteristics of the rotating surface. Upon being thrown from the rotating surface, or falling from that surface, the droplets and coated particles are solidified by exposure to air and are separated by sieving, or the like. The solidified droplets of pure coating material may be recycled into the suspension. Coating of all particles is achieved by dispersing the individual components of core material in the coating material before the resulting suspension reaches the rotating surface.
A method of coating or encapsulating individual mass components of core material having the form of solid particles, aggregates formed by granulation or liquid droplets with a coating of material that is less viscous than the core material and solid at normal room temperatures but liquid at elevated coating temperatures, or in the form of a solution during the coating process, said method comprising the steps of:
In a process for coating particles with a liquid coating, a method for obtaining individually coated particles while simultaneously facilitating removal of the coated particles from excess coating liquid with which the particles are mixed in a suspension, the method comprising feeding the suspension to a rotating surface to separate the suspension into coated particles and atomized liquid droplets expelled circumferentially from the surface, and rotating the surface at a speed for obtaining a predominance of the excess pure coating droplets of a predetermined size which is smaller than the size of the coated particles.
Dependencies are inferred from the claim text.