Abstract: A vacuum cleaner has a vacuum cleaner bag having two layers made of filter material, which are joined together on at least three sides to form an inner chamber. An inflow opening is formed on a fourth side between the two layers, at least in regions, into which a connector for connecting to a vacuum cleaner can be inserted.

Abstract: A vacuum cleaner bag includes an outside wall composed of filter material, having with an inflow opening formed therein and a shape to define a closed interior space except for the inflow opening. A tube structure is disposed within the interior space of the outside wall and comprises an air-permeable material having a flow-through opening in a center region aligned with the inflow opening.

Abstract: A filter bag includes a first filter material layer including an inflow opening, a second filter material layer having edges along which the second filter layer is joined to the first filter material layer to form an inside space; and a flat, multi-layer filter insert arranged in the inside space and having sections connected, respectively, to the first and second material layers. The filter insert has at least two outer layers defining an intermediate area there between. The intermediate area includes a center layer or an intermediate space for dust collection.

Abstract: A filter bag includes a first filter material layer including an inflow opening, a second filter material layer having edges along which the second filter layer is joined to the first filter material layer to form an inside space; and a flat, multi-layer filter insert arranged in the inside space and having sections connected, respectively, to the first and second material layers. The filter insert has at least two outer layers defining an intermediate area there between. The intermediate area includes a center layer or an intermediate space for dust collection.

Abstract: The invention is directed to a process for producing non-woven fabric materials in which nano- and/or microfibers are produced by an electrostatic spinning process from a polymer melt or a polymer solution and deposited to form a non-woven fabric. A carrier material in web form is arranged or is passed through between at least two spraying devices which are in the form of electrodes for producing an electrical field and each side of the carrier material is coated with the nano- and/or microfibers of opposite polarity, which are produced by means of the spraying devices.

Abstract: The inventions directed to a process for producing non-woven fabric materials in which nano- and/or microfibers are produced by an electrostatic spinning process from a polymer melt or a polymer solution and deposited to form a non-woven fabric. A carrier material in web form is arranged or is passed through between at least two spraying devices which are in the form of electrodes for producing an electrical field and each side of the carrier material is coated with the nano- and/or microfibers of opposite polarity, which are produced by means of the spraying devices.

Abstract: The subject of the invention is a process for the production of fibers or a fiber product in an electrostatic spinning process, wherein polymers are spun from solution and/or the melt and one or more oxidizable substances or substances with a &pgr;-electron system is or are added to the solution and/or the melt prior to the spinning operation.

Abstract: Proposed is a process for producing non-woven fabric materials in which nano- and/or microfibers are produced by an electrostatic spinning process from a polymer melt or a polymer solution and deposited to form a non-woven fabric, wherein a carrier material in web form is arranged or is passed through between at least two spraying devices which are in the form of electrodes for producing an electrical field and each side of the carrier material is coated with the nano- and/or microfibers of opposite polarity, which are produced by means of the spraying devices. A non-woven fabric material produced by that process and the use of the material are also subject-matter of the present invention.

Abstract: Proposed is a method of electrostatic spinning of polymers to obtain nano- and microfibers wherein at least one substance which can be easily converted into the gaseous phase with an electronegativity>2 or increased molecular mass is added to a polymer solution or melt or is introduced into the space between the electrodes of a spinning apparatus, whereby ionisation of the process air, that is to say the air between the electrodes of the spinning apparatus, is reduced. In that way fibers of a smaller diameter can be obtained and can be spun from solutions of a lower polymer concentration.

Abstract: The invention relates to oriented webs of meso- and nanotubes (hollow fibers) wherein the tubes or hollow fibers have an internal diameter of 10 nm to 50 &mgr;m and are preferentially oriented in one direction and to a process for their production.