PRODUCTION OF AIRTIGHT CYLINDRICAL BODY

摘要

PURPOSE:To obtain an airtight cylindrical body free from a seamed part and to easily produce a large-diameter pipe besides a small-diameter pipe by forming a thermoplastic synthetic resin layer on the whole circumferential surface of a tube. CONSTITUTION:A tube consisting of fibrous material such as nonwoven fabric and knitted fabric is flattened. A thermoplastic synthetic resin layer 3a is formed on the flat surface part 2a of a tube 1 formed thereby. Then the tube is reflattened so that the unformed part of the thermoplastic resin layer 3a on the tube 1 is made a flat surface part. A thermoplastic synthetic resin layer 3b is formed on the newly formed flat surface part 2b. The thermoplastic synthetic resin layers 3a-3d are formed while dividing the whole circumference of the tube 1 into three or more times by repeating such operation.