| 摘要 |
Securing a rigid or flexible filter (2) in a dimensionally stable frame (1) comprises stretching the filter and temporarily securing it in the frame using eg. a dot pattern (6a - 6c) or line of hot-melt glue, double-sided adhesive tape, etc. The frame is then at least partially surrounded by a preferably low permeability material (3), eg. needle-felt, that is subsequently secured in place by at least one seam (4), preferably a straight seam. The stitching for the seam passes through the material and filter inside but close to the frame to permanently secure the filter in place. |
