Abstract: The invention relates to a new base interlining for producing roofing membranes which have to meet a wide variety of requirements. The new base interlining provides a sufficient mechanical stability, good perforation strength, good tensile strength and a high resistance to thermal stress, inter alia required for base interlining during bituminization. In addition, the new base interlining requires a considerable reduced volume of impregnating bitumen when producing bituminized roofing materials and therefore high costs of special bitumens for filling the base interlining can be avoided. Beside the new base interlining, a method for producing it as well as roofing membranes comprising the base interlining are subject matter of this invention.

Abstract: A polyester filament nonwoven ply is suitable for roofing and roof-sealing webs and has a latent shrinkage force which counteracts drafting forces which may subsequently occur as the result of stresses or during thermal processing operations. The roofing webs thus remain dimensionally stable even when exposed to heat. The shrinkage force is obtained according to the claimed process by drafting the ply accordingly in a drafting mechanism arranged after a dryer.

Abstract: An improved bituminized flame-retardant textile material is provided that effectively overcomes bitumin adhesion difficulties associated with products of the prior art wherein the flame-retardant present on the surface of a textile support interfers with and hinders the achievement of bitumin adhesion. An anti-flame agent is applied in a quantity of 20 to 100 grams per square meter over 30 to 90 percent of the upper surface of the textile support. The remaining portions of the upper-surface of the textile support are free of the anti-flame agent. It surprisingly has been found that the surface portions of the textile support that are free of the anti-flame agent provide areas for the achievement of optimum bitumin adhesion with the textile support while still making possible entirely satisfactory flame retardancy for the overall product.