Dust filtration bag, e.g. for vacuum cleaner, includes a very open upstream layer only loosely attached to fine filtration downstream layers

摘要

The upstream layer is attached to the subsequent filtration layers over no more than 7 % of the total surface or is attached only round the edges. It has a surface weight of less than 30 g/m2>, preferably 10 to 25 g/m2> and a dust separation according to DIN 44956-2 of less than 50 %. The upstream layer can be a spunbonded, thermally bonded or wet-laid non-woven containing a high proportion of synthetic fibers. The thickness of the upstream layer is 0.05 to 0.25 mm. The remaining fine filtration layers of the dust filtration bag can be made up of various three-layer combinations of spunbonded or meltblown non-wovens or paper joined by ultrasonic welding or by adhesives. Each layer has a weight in the region of 20 to 60 g/m2>.