| 摘要 |
To produce a tubular filter (5), a continuous ribbon (11) of a porous and gas-permeable filter material is wound around a mandrel (10) in overlapping coils (12). The overlapping edges are durably bonded together by shaping the overlapping zones (15) to give profiled cross sections (17a,17b), using ultrasonic welding (20), so that they have a flush lock between them. The filter material is in two layers, with a micro-porous thermoplastic filter layer and a membrane layer. |
