| 摘要 |
<p>A disk cartridge is formed with a slidably mounted metallic shutter (11) for opening and closing a disk access opening formed in a cartridge shell. A stock roll material for forming the shutter is formed of a sheet of metallic base material (2), such as aluminium, to which upper (3) and lower (4) film layers are applied. The upper film layer (3) is formed of synthetic resin including a lubricant component and a colouring agent while the lower film layer (4) is formed of a synthetic resin which is harder than that of the first film layer (3) and to which no lubricant or colouring is added. The stock material is introduced to punching and bending processing apparatus (301) such that the upper lubricant containing film layer contacts the punch die (302) such that press oil need not be used during fabrication. Bending processing is carried out such that a U-shaped shutter (11) is formed having the lubricant containing film layer (3) at an inner surface thereof, and the harder lower film layer (4) forms the outer surface. Thus, the outer surface resists abrasion and flawing and may be printed upon with good results, while the inner lubricated layer ensures smooth sliding of the shutter (11) and eliminates the need for applying and removing press oil during manufacture. The colour applied to the lubricated film layer (3) ensures that the stock may always be correctly oriented at the initial stage of processing. <IMAGE></p> |
