Filter element and process for producing a filter element

摘要

The invention relates to a hotmelt adhesive comprising a hotmelt adhesive mixture, the mixture including a) 15-85% by weight of a first, polyester-based hotmelt adhesive and b) 15-85% by weight of a second, polyamide-based hotmelt adhesive.

主权项

1. A filter element, comprising:
a zigzag-folded filter bellows that is formed from a flat filter medium; wherein the filter bellows is glued together by at least two regularly or irregularly interrupted, adhesive beads of a hotmelt adhesive system that are extending on the filter medium; wherein the hotmelt adhesive system comprises a hotmelt adhesive mixture, the hotmelt adhesive mixture consisting of:
15-85% by weight of a first hotmelt adhesive that is polyester-based; and15-85% by weight of a second hotmelt adhesive that is polyamide-based;wherein the weight proportions of the first and of the second hotmelt adhesives together constitute 100% by weight of the hotmelt adhesive mixture; wherein the hotmelt adhesive mixture has a proportion of more than 75% by weight in the hotmelt adhesive system; wherein a remainder of the hotmelt adhesive system is formed fillers, including one or more of: chalk, titanium dioxide as a white pigment, a tack-providing resin, at least one further hotmelt adhesive on polycondensate basis; a zigzag-folded filter medium, which separates a raw side from a clean side of the filter element; wherein the zigzag folds of the filter medium have alternating fold tips and fold bottoms; wherein hotmelt adhesive beads are arranged in the fold interstices, the fold interstices extending alternatingly between the fold tips and the fold bottoms, wherein on the raw side as well as on the clean side of the filter medium at least two elongated adhesive beads are arranged extending parallel to each other and perpendicular to a direction of extension of the fold edges; wherein the adhesive beads on the raw side and/or the clean side are interrupted at regular intervals providing gaps in the respective adhesive bead where adhesive is not present, the intervals having an interval beginning point and end point; wherein the beginning and end points of the interruptions of the parallel extending adhesive beads are positioned to lie on one or more pre-defined straight lines, the predefined straight lines traversing across a plurality of said adhesive beads and interconnecting end points of said traversed plurality of adhesive beads; wherein the plurality of straight lines extend parallel to each other and, relative to the fold edges, are positioned at an angle of 10-80 degrees.