| 摘要 |
PURPOSE:To reliably put on the mutual overlapping portions of films and to attain good heat insulation in case of a curtain for an agricultural house by using a tapered winding core to completely avoid meandering and unbalance in length of the let-out film at the time of unwinding a film roll. CONSTITUTION:A winding core 1 of a film roll is tapered, and a film is taken up on the winding core 1, with the winding start end positioned at the smaller diameter side. At the time of unwinding the thus formed film roll, the film is prevented from meandering. In case of utilizing such winding core for a curtain for an agricultural house, the mutual overlapping portions of films can be reliably put on to maintain heat insulation favorably. |
