Abstract: A filter is formed by a multilayer filter medium comprising at least one textile supporting layer, at least one filter layer which is applied to at least one side of the supporting nonwoven, wherein the filter layer is constructed from glass fibres, and at least one textile covering layer which is applied to the filter layer, wherein the filter layer comprises a mixture of at least two types of glass fibres, wherein the first glass fibre type of the mixture has a diameter of 0.6 ?m±0.3 ?m, and wherein the second glass fibre type of the mixture has a diameter of 1.0 ?m±0.3 ?m, and wherein the first and second glass fibre types of the mixture are present in a ratio by weight in the range 1:1.1 to 1:4.

Abstract: The present invention relates to a filter composed of a multi-ply filter medium, which comprises at least one non-woven stiffening layer, at least one filtration layer, at least one covering layer and where necessary at least one non-woven microfibre layer, the non-woven stiffening layer comprising fibres of synthetic polymers and the fibres being both partially oriented and oriented fibres.

Abstract: The present invention relates to a filter composed of a multi-ply filter medium, which comprises at least one non-woven stiffening layer, at least one filtration layer, at least one covering layer and where necessary at least one non-woven microfiber layer, the non-woven stiffening layer comprising fibers of synthetic polymers and the fibers being both partially oriented and oriented fibers.

Abstract: The present invention relates to a filter composed of a multi-ply filter medium, which comprises at least one non-woven stiffening layer, at least one filtration layer, at least one covering layer and where necessary at least one non-woven microfibre layer, the non-woven stiffening layer comprising fibres of synthetic polymers and the fibres being both partially oriented and oriented fibres.

Abstract: In accordance with the invention, a laminate of two or more layers and the method of making it is provided. The laminate includes at least one organic synthetic filament non-woven layer, and at least one woven web or scrim of glass fibers pre-consolidated by a binding agent. The polyester non-wovens and the woven webs or scrims are bound by needling such that a part of the (e.g., polyester) filaments penetrate through the laminate and emerge at the lower surface of the laminate and lie adjacent thereto The formed laminate is subjected to a final consolidation by an acrylate or a styrene binder.