| 主权项 |
1. A filter element comprising:
a multi-layered filter medium comprising a plurality of layers and folded along folding lines; a first one of the plurality of layers is a plastic mesh configured to absorb traverse forces, the plastic mesh having crossing plastic threads, the crossing plastic threads having a second set of plastic threads crossing a first set of plastic threads at a thread angle of between 70 degrees to 102 degrees; a second one of the the plurality of layers is a meltblown layer of meltblown fibers selected from the set of: polybutylene terephthalate (PBT) meltblown, polyamide (PA) meltblown, polypropylene (PP) meltblown and polyether sulfone (PES) meltblown; wherein the first and the second layers individual layers lie loosely on top of each other; wherein the multi-layered filter medium has at least one functional region in at least one section located between adjacent folding lines, wherein the at least one functional region is a first embossment; wherein the layers of the multi-layered filter medium are firmly bonded to each other along the first embossment; wherein the at least one functional region is a plurality of spacer knobs or stabilizing knobs formed as half cylinder shell projections into a flat sections of the filter medium between two adjacent fold lines of the filter medium; wherein the spacer knobs or stabilizing knobs are embossments into the plurality of layers between two adjacent fold lines of the filter medium, the embossments formed by energy-inducing embossing; wherein the folding lines are embossed so that second embossments are formed along the folding lines by energy-introducing embossing and the layers of the multi-layered filter medium are thereby firmly bonded to each other along the second embossments; wherein between the fold lines and the spacer knobs, the plastic mesh and the meltblown layer are not connected to each other and can still align themselves relative to each other. |
