Method for coating glass containers

DETAILED DESCRIPTION The present invention meets this need by providing a method and apparatus for coating a glass container (bottles, jars, tubes, etc.
) with a layer of plastic by rotating the container about a horizontal axis while moving the container past a coating station having a plurality of liquid applicator nozzles.
Each nozzle means, or series of applicator tubes, applies an uncured liquid plastic such as polyurethane to an associated area of the container as the container is moved past the coating station in a direction perpendicular to the container axis.
Means are provided for supplying predetermined quantities of uncured liquid plastic (which may vary in composition, amount, color, etc.
) to respective ones of the nozzle means.
Means are also provided for rotating the coated container slowly as the coated container moves through a curing zone and for cleaning the nozzle means by pumping solvent therethrough.
With this arrangement of apparatus means, it is possible to efficiently coat a large number of containers rapidly and effectively.
In general, the preferred method performed with this apparatus is for coating glass bottles and is as follows: (a) the bottles are cleaned in a standard bottle washing process, (b) a silane primer is applied from a solvent mixture and the bottles are dried to remove the solvent; this may be performed as a part of the continuous flow coating process or prior to introducing the bottles into that process, (c) if priming is done as a pre-treatment, the primed bottles are loaded onto the continuous conveyor, (d) if desired, the bottles may be passed through a preheat (110.
degree.
F.
-130.
degree.
F.
) to remove any remaining solvent from the primer and assist in flow of the uncured polyurethane liquid plastic, (e) the uncured polyurethane liquid plastic is mixed and metered in predetermined amounts to each nozzle means (for example, four series of applicator tubes varying from 10-26 tubes each) and cast from the separate nozzle means as the bottle is rotated at approximately 40-60 RPM beneath the nozzle means; the bottle may make one or two revolutions per cast cycle, each casting cycle lasting 1-1