| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a covering material for efficiently manufacturing a covering material having quarter-circular welded parts (R parts) at four corners from a raw material film on a manufacturing line using a side seal method, and to provide a packaging material manufactured by the method. SOLUTION: This manufacturing method comprises: a step of film folding where both side edges 1a of a thermoplastic synthetic resin raw material film 1 are folded inward while the film 1 is continuously fed; a first welding/cutting step where both the edges 1a of the film 1 are welded and cut in valley shapes with both diagonal sides curved protrusively in quarter circular shapes at a predetermined pitch while the film 1 whose both side edges 1a are folded is intermittently fed; and a second welding/cutting step where the film is laterally welded and cut along a line connecting bottoms of the facing valley shaped welding/cutting parts of the side edges 1a. A covering material obtained by this manufacturing method, e.g. a book cover 10, has quarter-circular welding/cutting parts 1d at four corners and eliminates the danger of hurting the fingers by a sharp corner. COPYRIGHT: (C)2008,JPO&INPIT
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