| 摘要 |
A filter element (10) comprises two corrugated layers (11, 12) of fusible filter media arranged superimposed to define elongate air flow passages (23) therebetween, and between said corrugated layers an internal support structure (16) which extends across a substantial part of the width of the element and along a substantial part of the length of the element to separate at least a part of one corrugated layer from direct contact with the other layer, the layers (11, 12) of fusible filter media being fused relative to one another for example by ultrasonic welding to provide a structural interconnection which inhibits separation of said layers when the pressure in the passages (23) exceeds the external pressure. |
