| 摘要 |
PROBLEM TO BE SOLVED: To provide a duct superior in a heat-insulating property and workability in production even with simple composition. SOLUTION: This duct 1 is produced by covering an outer peripheral surface of a duct body 3 forming a flow passage 2 for fluid with a cover layer wall 5. The cover layer wall 5 is constituted by a heat contractive foamed resin sheet 6. The outer peripheral surface of the duct body 3 is covered with the heat contractive foamed resin sheet 6 thermally contracted. A clearance 7 is formed between the outer peripheral surface of the duct body 3 and the cover layer wall 5 by a protrusion 4. The heat contracted foamed resin sheet 6 constituting the cover layer wall 5 is polyethylene (a low density polyethylene, straight chained low density polyethylene, or polyethylene prepared with the usage of a metallocene catalyst), polypropylene, polyvinyl chloride, polystyrene, polyamide, or polyethylene terephthalate. |
