| 摘要 |
<p>A replaceable filter cartridge has a pleated paper filter medium (4) mounted within a frame or casing (1) having a closed side and an open side, the open side being covered by a removable protective tray (6) or lid the internal shape of which has been used in manufacture for moulding a sealing surface (14) onto the periphery of the frame or casing, the closed side of the frame or casing being provided with a perforated portion (3) which is also removable for use of the filter cartridge.</p> |
