| 摘要 |
PURPOSE:To prevent a loading defect at the time of loading of a film into a camera or the rolling defect and loosening of winding in the camera by specifying the thickness, tensile strength in the transverse direction, etc., of the light shielding paper and sealing paper to be wound together with a photographic film on a spool. CONSTITUTION:A narrow part 7 at the front end of the light shielding paper 3 and a tapered part 8 thereof are partly folded at a folding line 6 and the sealing paper 4 for preventing loosening is stuck thereto. Tearing of the sealing paper having a width (b) by holding the turn back part (a) is generally practiced in order to unseal the film at the time of loading of the film to the camera and, therefore, the tensile strength in the transverse direction of the light shielding paper is required to be made higher than the tensile strength in the transverse direction of the sealing paper; however, the light shielding paper loses resilience if the thickness thereof is increased. The rolling defect and the loosening of the winding are then resulted. The overall thickness of the light shielding paper is, therefore, confined to <=95mum and the tear strength thereof to <=2.0kg/cm<2>; further, the tensile strength in the transverse direction thereof is confined to <=3.5kg/cm<2>. The overall thickness of the sealing paper is confined to <=80mum, and the tensile strength in the transverse direction thereof to <=2.5kg/cm<2>. Further, the width size thereof is confined to <=20mm. The purpose is thus attained. |
