| 摘要 |
A filter comprising a single length of filter material with a longitudinal axis wherein the length of filter material has a contour of elongated depressions and swells or apices substantially parallel to the longitudinal axis, the filter material further has folds substantially perpendicular to the longitudinal axis of the filter material forming pleats at substantially equal intervals. A process of making the filter and apparatus used in the process are a part of the instant invention. |
