Patent ID: 8828501

Claim:
A drying method for drying a coating layer which is formed by coating a moving web with a coating solution containing organic solvent, comprising steps of: drying said web by a drying device which comprises a casing surrounding the web at a transporting position just after the coating and before a blow drying apparatus, so as to prevent wind disturbance close to a coating surface, wherein the casing is tightly closed such that a wind velocity is at most 0.1 m/s when the web is not transported in the drying device, the web being transported almost perpendicularly inside the casing; heating with a heating device which is disposed within the casing, such that a temperature difference |T2−T1| between a temperature T1 of said coating layer at the entrance of said casing and a temperature T2 of said coating layer at the exit of said casing at most 5° C., wherein at least 70% by mass of said organic solvent in said coating solution is dried in said drying device; and further drying said coating layer by the blow drying apparatus disposed downstream from said drying device and disposed outside said casing, wherein a web guide roller is disposed within said casing and said guide roller is a roller whose temperature is controlled to facilitate drying.