| 摘要 |
PROBLEM TO BE SOLVED: To provide a forming method of a tough joint such that a portion having different strength from that of another portion is not continuously formed at both side margins of a heat-welded portion in case of lapping ends of a film on each other or butt-jointing them using a joint tape to heat-weld them, and that if a tear occurs, the tear does not propagate, and to provide a film for agriculture. SOLUTION: In a broadened film made by lapping the side margins of a pair of thermoplastic films 10a and 10b on each other or butt-jointing the side margins and lapping a joint tape T followed by heat-welding the films themselves or heat-welding the film and the joint tape T, an uneven shape is formed along the lengthwise direction of the heat-welded portion 13. COPYRIGHT: (C)2007,JPO&INPIT |
