Drying and curing apparatus

Claim 1

In an apparatus for drying and curing a plastic resin and the like applied in a dissolved state in a solvent onto a long sheet material such as paper or fabric, comprising a vertically extending heating chamber having an inverted U-shaped configuration and having at its lowermost parts an inlet and an outlet, means for moving the material through said heating chamber from said inlet to said outlet, means for circulating heated air through said chamber from a location adjacent said outlet to a location adjacent said inlet in the direction counter to that of the material travel, and means connected to said chamber at said location adjacent said inlet for exhausting the air from within the chamber to recover the solvent and for recirculating the air to said location adjacent the outlet into the chamber; the improvement comprising, a second heating chamber having a vertically extending and inverted U-shaped configuration and operating at a temperature higher than that in the first heating chamber, said second chamber having at one of its lowermost parts an inlet communicatively connected to said outlet of said first heating chamber and at the other lowermost part an outlet, means operatively associated with said second heating chamber for moving the material which has passed through said first heating chamber through said inlet of the second heating chamber into the same and passing it upwardly and then downwardly through the second chamber to deliver it through said outlet of the second chamber means for supplying a much smaller quantity of heated air and at a higher temperature than in the first heating chamber from a location adjacent said outlet of the second chamber into the second chamber and for causing the air to flow in the direction counter to that of the material travel in the second chamber, and means operatively connected to said second chamber for exhausting the quantity of air supplied into the second chamber through a location adjacent said inlet of the second chamber without recirculating the air into the second chamber.