US 4,025,664 A · Container coating method

Abstract

A method for coating a cylindrical container with a thin, resinous coating by spraying powdered resin is disclosed. The technique involves spraying of finely divided resin particles at a velocity of at least about 200 feet per minute from a spray nozzle external to the container into the interior of a rapidly revolving container, particularly slender, cylindrical containers. The container may be sprayed by directing a pulse of a predetermined quantum of resin into the container to deposit a substantially uniform coating. Alternatively, a continuous flow of resin at a predetermined rate may be sprayed into a container. The resin particles are caused to adhere to the container by preheating the container. The coating is rendered continuous by preheating the container to temperatures above the softening point of the resin. Postheating of the coated container at temperatures in excess of about 300.degree. F matures the coating.

Claims27

Dependent claims

A process for coating the entire interior surface of a cylindrical type container having one open end and one closed end with an ultra-thin polymeric coating comprising:

a. preheating said container to a temperature of at least about 150.degree. F.;
b. spraying into the interior of said container from a location outside of said container a quantum of finely divided resin particles having maximum individual particle diameters of less than about 20 microns and a softening point less than about 150.degree. F. sufficient to coat the container interior with a continuous film, said resin entrained in a gas stream traveling at a velocity sufficient to create substantial turbulence in said container;
and
c. rotating said container rapidly to create a vortex therein and to cause said container to rotate at least two revolutions during spraying of the resin particles.

1 more element

Dependencies are inferred from the claim text.

Container coating method

Life of this patent

Container coating method

Life of this patent

Abstract

Claims27