| 摘要 |
The invention relates to a longitudinally creped paper web for use in the manufacture of filter rods. In order to improve the filtering capacity and resistance to flow therethrough without weakening filter plugs formed from the web in respect of resistance to radial crushing the longitudinally creped web is provided with linear indentations transversely thereof which are sufficiently closely spaced one from the other longitudinally of the web to provide consistency in draw of short length sections cut from filter plugs made from the web. The invention also relates to the process and apparatus for forming such a filter web using co-operating spaced rollers for forming controlled linear compression zones extending transversely of the web, at least one of these two rollers being provided with ribs extending at least approximately axially of the roll. A drive to the two rollers is synchronized so that the surface speed of both the rollers is at the same speed as the speed of advance of the web being treated thereby. The treated web may either be formed into a roll or coil for storage and subsequent use or may be fed directly to a tow machine in which it is formed at once into filter plugs in the conventional manner. The invention also relates to filter plugs of which the filling comprises the gathered together material web. |
