Recirculating coating liquid supply system with viscosity regulation

A recirculating coating liquid supply system for continuous delivery of a supply of coating liquid to a coating apparatus, the coating liquid comprising a mixture of coating liquid base and coating liquid thinner, the supply system comprising a holding tank for the coating liquid mixture, an applicator trough associated with the coating apparatus, conduit means for circulating coating liquid mixture from the holding tank to the applicator trough and from the applicator trough back to the holding tank, the conduit means including a main feed line having an inlet at the holding tank and an outlet at the applicator trough and a return feed line having an inlet at the applicator trough and an outlet at the holding tank, a main pump positioned in the main feed line, the main pump dividing the main feed line into an upstream section and a downstream section, a viscometer, means operatively connecting the viscometer to the upstream section of the main feed line, a coating liquid base tank, the coating liquid base tank carrying a supply of coating liquid base, a line connecting the coating liquid base tank with the downstream section of the main feed line, a dosing pump operatively connected to the line connecting the coating liquid base tank with the downstream section of the main feed line for introducing a measured quantity of coating liquid base to the liquid coating mixture flowing through the main feed line for adjustment of its viscosity, a supply of coating liquid thinner, a line interconnecting the coating liquid thinner supply with the downstream section of the main feed line and a dosing pump operatively connected to the line interconnecting the coating liquid thinner supply with the downstream section of the main feed line for introducing a measured quantity of coating liquid thinner into the main feed line for adjustment of the viscosity of the coating liquid mixture flowing through the main feed line.

A recirculating coating liquid supply system for continuous delivery of a supply of coating liquid to a coating apparatus, the coating liquid comprising a mixture of coating liquid base and coating liquid thinner, the supply system comprising a holding tank for the coating liquid mixture, an applicator trough associated with the coating apparatus, conduit means for recirculating coating liquid mixture from the holding tank to the applicator trough and from the applicator trough back to the holding tank, the conduit means including a main feed line having an inlet at the holding tank and an outlet at the applicator trough, the conduit means further including a return feed line having an inlet at the applicator trough and an outlet at the holding tank, the supply system further including a supply of compressed air, and means for expelling coating liquid from the main feed line into the applicator trough, the means for expelling including means for operatively connecting the supply of compressed air to the main feed line for the introduction of compressed air into the main feed line, means for draining the expelled coating liquid mixture from the applicator trough, means operatively connected to the means for draining for collecting the drained coating liquid mixture, a coating liquid thinner supply, and means for selectively interconnecting the coating liquid thinner supply with the main feed line for flushing the main feed line with coating liquid thinner, the applicator trough including means for collecting the coating liquid thinner flushed through the main line, the supply system further including means for draining the applicator trough of coating liquid thinner and means for collecting the drained coating liquid thinner.