Filter bag for a pocket air filter and method for the production thereof
First Claim
1. A filter bag comprising first and second side walls formed of air-permeable filter material, the first side wall including two lateral edges welded to respective lateral edges of the second side wall, and a base edge welded to a base edge of the second side wall;
- the first and second side walls including respective first and second inside surfaces facing one another; and
a spacer disposed between the first and second side walls for separating the first and second side walls, the spacer defined by a single strip of flexible material which constitutes a separate strip with respect to the first and second side walls, the strip extending from one welded pair of lateral edges to the other welded pair of lateral edges while welded alternately to the inside surfaces of the first and second side walls, wherein the spacer is welded at a plurality of locations to each of the first and second side walls.
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Abstract
A filter bag for a pocket air filter includes two side walls. Both lateral edges of the side walls, and the edge of the base are welded to each other. The side walls are made of an air-permeable filter material which can be ultrasonically welded, and at least part of the surface of said side walls is joined by means of interconnected welded spacer elements running substantially parallel to said side walls. The spacer elements are formed by an intermediate layer made from a strip of flexible material, which is alternately welded to the side walls in zig-zag fashion.
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Citations
10 Claims
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1. A filter bag comprising first and second side walls formed of air-permeable filter material, the first side wall including two lateral edges welded to respective lateral edges of the second side wall, and a base edge welded to a base edge of the second side wall;
- the first and second side walls including respective first and second inside surfaces facing one another; and
a spacer disposed between the first and second side walls for separating the first and second side walls, the spacer defined by a single strip of flexible material which constitutes a separate strip with respect to the first and second side walls, the strip extending from one welded pair of lateral edges to the other welded pair of lateral edges while welded alternately to the inside surfaces of the first and second side walls, wherein the spacer is welded at a plurality of locations to each of the first and second side walls. - View Dependent Claims (2, 3, 4, 5)
- the first and second side walls including respective first and second inside surfaces facing one another; and
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6. A method of producing filter bags comprising the steps of:
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A) arranging first and second continuous outer strips in superimposed relationship, with a continuous intermediate strip disposed therebetween, the first and second outer strips including respective first and second inside surfaces facing one another, the intermediate strip constituting a separate strip with respect to the first and second outer strips;
B) applying an ultrasonic welding device to one of the first and second outer strips at spaced weld locations therealong; and
C) introducing, at each of the weld locations, a non-weldable separating plate, whereby the plate is introduced between the intermediate strip and alternating ones of the first and second outer strips at successive ones of the weld locations to cause the intermediate strip to be welded alternatively to the first and second inside surfaces of the first and second outer strips along a weld seam extending perpendicularly to the longitudinal direction separating the weld locations, wherein the plate is welded at a plurality of locations to each of the first and second inside surfaces. - View Dependent Claims (7, 8, 9, 10)
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Specification