| 摘要 |
<p>This invention relates to a method and apparatus for perforating the walls of an assembled filter element used on smoking products including a continuously moving conveying means for receiving a plurality of said filter elements and means for retaining said assembled filter elements on said conveying means, a plurality of piercing elements positioned at right angles to the direction of movement of said assembled filter elements, and a means for manipulating the piercing elements so that it penetrates and withdraws from the walls of the filter element.</p> |
