| 摘要 |
PROBLEM TO BE SOLVED: To provide a sock duct that always has a superior appearance, is easy to manufacture, is lightweight, is easy to perform handling and construction and the like, can be partially replaced in the case of clogging, and can exhibit sufficient noninflammable performance.SOLUTION: A sock duct 1 includes an outer surface forming member 10 and a shape holding member 20. The outer surface forming member 10 is composed of a cylindrical air-permeable cylindrical flexible material. The shape holding member 20 includes: a cylindrical body 22 formed into a cylindrical shape, by spirally winding the edges of an air-permeable sheet with a predetermined width so that the edges are overlapped with each other; and a spiral member 30 with necessary rigidity, which is fixed to the position where the edges of the sheet of the cylindrical body 22 are overlapped with each other; wherein at least one of at least one layer of the outer surface forming member 10 and the cylindrical body 22 of the shape holding member is composed of a nonflammable material, and the outer surface forming member 10 is provided detachably to the shape holding member 20 while covering an outer periphery of the shape holding member 20. |
