| 摘要 |
<p>PURPOSE:To prevent a container from deforming and an explosion sound from being generated by making the internal diameter of a bottom part smaller than the internal diameter of an opening part and then preventing negative pressure from being produced in the container main body when a metallic core is extracted from the container main body at the time of the molding of the container. CONSTITUTION:The peripheral wall part 6 of the container main body for the photographic film cartridge is reduced in thickness from the boundary of bottom part 3 toward the opening part 7, its external surface is formed in a parallel columnar shape, and the internal surface is expanded toward the opening part 7. Then this container main body is so formed that the internal diameter (a) of the bottom part 3 is 29.3 mm, the internal diameter (b) of the opening part 7 is 31.5 mm, and the internal angle alpha between the internal surface of the bottom part 3 and the internal surface of the peripheral wall part 6 is 91 deg.. Therefore, when injection molding is performed, the molding cycle is not made slow and when the metallic mold core is extracted, deformation and explosion sound generation are precluded.</p> |
