US 4,442,143 A · Catalytic curing of coatings

Abstract

A method of curing a wet catalyst-curable resin on a substrate in which the substrate is passed through a treating zone provided by a sealed vapor-curing chamber connected to sealed entrance and exit ante chambers at respective ends. The ante chambers are each separated from the vapor-curing chamber by a wall provided with a passage having height-adjustable means to limit passage of gas. The substrate is passed in turn through the entrance chamber where the boundary layer of air is substantially replaced by inert gas, through the entrance chamber into the vapor-curing chamber where it is exposed to the catalyst vapor, and then through the exit chamber where the curing vapor is removed. When a web provides the substrate, a jet of curing vapor is impinged on the web surface as it enters the vapor-curing chamber at an angle and at a velocity effective substantially to remove the barrier layer of gas and permeate the coating. In starting up the entrance and exit chambers and vapor-curing chamber are purged with inert gas thereby to remove air and on termination of the curing operations the vapor-curing chamber is purged with inert gas to remove curing vapor. Apparatus is disclosed for carrying out the method, featuring height-adjustable doors between the vapor-curing chamber and the entrance and exit chambers. Other features are labyrinth seals and turning vanes adjacent to the passage from one chamber to the other to minimize escape of gas.

Claims14

Dependent claims

An apparatus for curing a wet catalyst-curable resin on a substrate with a vapor containing a catalyst, comprising,

a treating zone provided by a sealed vapor-curing chamber connected to a sealed entrance chamber at one end and a sealed exit chamber at the other end, the entrance and exit chambers each being separated from the vapor-curing chamber by a wall, each wall being provided with a passage,
each passage being provided with height adjustable means to limit the escape of vapor from the curing chamber,
conveying means running through the treating zone,
a curing vapor generator,
a source of inert gas,
a connection from the inert gas source to the generator,
an impinger near the entrance of the vapor-curing chamber for projecting catalyst vapor against the substrate, and a connection from the vapor generator to the impinger,
connections from the inert gas source to the vapor-curing chamber and to the entrance and exit chambers,
exhaust and scrubber means,
connections from the vapor-curing chamber and entrance and exit chamber to the exhaust and scrubber means,
means for flushing inert gas, from the gas source, through the vapor-curing chamber to the exhaust and scrubber means, for purging the vapor curing chamber,
a connection from the inert gas source to the entrance chamber to provide it with an atmosphere of inert gas to replace the boundary layer of air on the substrate passing through it with a boundary layer of inert gas,
a connection from the inert gas source to the exit chamber to provide it with an atmosphere of inert gas to replace the boundary layer of curing vapor with inert gas,
and control means for controlling the respective gas and vapor connections to balance scour flow and catalyst to achieve minimum dilution of the catalyst vapor and to maintain minimum catalyst concentrations in the chamber.

11 more elements

Dependencies are inferred from the claim text.

Catalytic curing of coatings

Life of this patent

Catalytic curing of coatings

Life of this patent

Abstract

Claims14