The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 31, 1976
Filed:
Dec. 12, 1974
Robert M Martin, Golden, CO (US);
Coors Porcelain Company, Golden, CO (US);
Abstract
In accordance with the invention, hollow pellets having outer surfaces of one material and inner surfaces of another material are manufactured by dropping drops of liquid into a bed of powder containing the material of which it is desired to make the outer surface portions of the hollow pellets and preferably also a binder, the liquid containing the material of which it is desired to make the inner surface portions of the hollow pellets. When the drops of liquid fall into the powder, the powder immediately forms a spherical shell around each drop so as to form the hollow pellets upon vaporization of the liquid. It is preferred that the powder additionally contain some sodium bicarbonate or the like and that the liquid be an aqueous acid solution such that, upon initial formation of the spherical shell of powder, the acid reacts with the sodium bicarbonate to generate carbon dioxide which causes the spherical shell to expand while yet additional powder coalesces onto the shell. This results in hollow pellets wherein the inner surfaces are formed from material included in the liquid and the outer surfaces are formed from material included in the bed. The method is particularly useful for the manufacture of pellets wherein at least the outer surfaces are of ceramic, there being a firing operation on the pellets after removal from the powder bed so as to sinter the ceramic to monolithic structure.