| 摘要 |
A fluid filter is formed by producing an air laid nonwoven batt comprising a randomly arranged mixture of thermoplastic fibers and fibers which are not thermoplastic. The batt is then cut into sections, and portions of the batt are heated to a temperature sufficient to partially fuse the fibers, thereby increasing the density of the portion of the batt which is heated. Accordingly, a gradient density filter may be produced having a progressively greater density from the fluid receiving side to the fluid expressing side, so that larger particles are trapped at the fluid receiving side and progressively smaller particles are trapped as the fluid flows through the media, with the finest particles being trapped at the fluid expressing side. |
