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: Composites made from at least two plies are described, where one of the outer layers is a layer comprising glass fibers, and in particular is a staple glass fiber nonwoven. The layers have been bonded to one another by needling, and the extent of this needling is such that some of the fibers of the organic nonwoven emerge from the surface of the glass fiber sheet. The composite is then provided with a binder by using a rotating roll for single-side application to the glass fiber surface. The composites are particularly suitable for producing bituminized prefabricated roofing and waterproofing sheets, and as backings for coatings, e.g. PVC coatings.

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.

Abstract: The present invention provides non-woven laminate that is not subjected to final consolidation by a binder and the production thereof. The laminate includes at least one non-woven mat containing glass staple fibers pre-consolidated with a resin, and at least one non-woven layer of synthetic fibers. The synthetic non-woven layers and the pre-consolidated non-woven mat of glass fibers are bounded together by needling such that a portion of the fibers of the upper synthetic non-woven layer passes through the non-woven mat of glass fibers possibly through the underlying synthetic non-woven layer. The synthetic fibers are heat shrunken and the laminate is binder free.

Abstract: There are described a dimensionally stable laminate whose surfaces are formed by spunbonded webs and comprising at least two layers of spunbonded and at least one laid layer of reinforcing yarn, the laid layer or layers each being disposed between two layers of spunbonded and having a thread density of from 0.5 to 3 threads/cm, spunbonded and laid layers having been joined together by needling at about 20-70 stitches/cm2, a process for manufacturing this laminate, and its use for manufacturing roofing sheets and roof sealing sheets.