Abstract: Disclosed is an air filter element (200) for insertion into an air filter housing, comprising an intake surface (275), a discharge surface (285), a filter medium (210), and a filter element-retaining device (240) which extends along at least a section of the periphery of the filter medium (210), between the intake surface (275) and the discharge surface (285), and which includes a retaining arrangement (270) that radially projects from the filter medium (210).

Abstract: A filter element has a filter body with a longitudinal axis, the filter body having a first end face and a second end face opposite the first end face. A first end plate is arranged at the first end face and has an open or closed configuration. A second end plate is arranged at the second end face. A support tube is arranged concentrically to the longitudinal axis and extends between the first and second end plates. The first end plate is reinforced by a reinforcement ring. The reinforcement ring has first openings that are visible from the exterior of the reinforcement ring, wherein the first openings enable a filling level check of a filling level of a material that connects the first end plate with the first end face.

Abstract: A filter body has a longitudinal axis and a first end face and a second end face opposite the first end face in a direction of the longitudinal axis. The filter body has a zigzag-folded filter medium arranged about the longitudinal axis, wherein the filter body has an inner circumference and an outer circumference and fold edges of the filter medium are positioned on the inner circumference and/or the outer circumference. The filter body further has a securing coil of at least one circumferentially extending thread applied onto the outer circumference. The fold edges have, at least over sections thereof, several embossments arranged such that the fold edges that are next to each other are secured relative to each other by the embossments.

Abstract: A compact filter has a compact filter element for exchangeable use in a filter housing and the compact filter element has a filter body of a web-shaped filter medium. The web-shaped filter medium has at least one flat filter medium web and one corrugated filter medium web that are placed onto each other and at least partially connected to each other by ultrasonic welding. At least one of the flat and corrugated filter medium webs is a composite filter medium web of at least two components, wherein at least one component is a synthetic material and one component is a non-synthetic material. The non-synthetic material is a plant-derived material and forms a support of the composite filter medium web and the synthetic material is a synthetic layer applied on the support.

Abstract: A compact filter has a compact filter element for exchangeable use in a filter housing and the compact filter element has a filter body of a web-shaped filter medium. The web-shaped filter medium has at least one flat filter medium web and one corrugated filter medium web that are placed onto each other and at least partially connected to each other by ultrasonic welding. At least one of the flat and corrugated filter medium webs is a composite filter medium web of at least two components, wherein at least one component is a synthetic material and one component is a non-synthetic material. The non-synthetic material is a plant-derived material and forms a support of the composite filter medium web and the synthetic material is a synthetic layer applied on the support.

Abstract: A filter element for cleaning a fluid having a pleated filter medium designed for radial flow, to the outside of which a circumferential reinforcing thread is applied. The outside of the filter medium is divided into two axial sections, to which the reinforcing thread is applied in a plurality of circumferential thread windings, such that the axial distance between directly adjacent thread windings differs in the two sections.

Abstract: A filter element for cleaning a fluid having a pleated filter medium designed for radial flow, to the outside of which a circumferential reinforcing thread is applied. The outside of the filter medium is divided into two axial sections, to which the reinforcing thread is applied in a plurality of circumferential thread windings, such that the axial distance between directly adjacent thread windings differs in the two sections.

Abstract: The invention relates to a multi-layer filter element. The invention provides a main filter layer which preferably consists of a melt-blown fleece and has an absolute filtration capability. A paper layer (2) on the clean side supports the filter element and does not contribute to the filtering of the fluid to be filtered. Said layer can therefore have a macropore structure, thereby allowing a low flow resistance. A layer (3)on the clean side which preferably also consists of paper serves to pre-filter the fluid and to protect and support the main filter layer. The inventive design of the multi-layer filter material provides a means for economically producing filter elements, especially filter cartridges which are folded in the shape of a star, since no trellis protective layers are necessary. The invention also facilitates an improved thermal disposability of the proposed filter cartridge.