Abstract: A mat useful for reinforcing composite materials is made up of at least first and second sets of fibers, the first set of fibers laid as a ply in spaced apart parallel relationship in the direction of construction and the second set laid as a ply in spaced apart parallel relationship perpendicular to the direction of construction. These fibers define interstices, into which a continuous filament is knitted to provide stability. The filament has a core portion and a sheath portion, the sheath portion having a lower melting point than the core portion. The sheath portion is thermally fusible to form a plurality of closed loops in which the respective sets of fibers are entrapped. The fibers are glass or glass rovings and the filament is a polyester, the core portion being a high-viscosity poly(ethylene terephthalate) and the sheath portion being a low-viscosity poly(ethylene terephthalate).

Abstract: A mat useful for reinforcing composite materials is made up of at least first and second sets of fibers, the first set of fibers laid as a ply in spaced apart parallel relationship in the direction of construction and the second set laid as a ply in spaced apart parallel relationship perpendicular to the direction of construction. These fibers define interstices, into which a continuous filament is knitted to provide stability. The filament has a core portion and a sheath portion, the sheath portion having a lower melting point than the core portion. The sheath portion is thermally fusible to form a plurality of closed loops in which the respective sets of fibers are entrapped. The fibers are glass or glass rovings and the filament is a polyester, the core portion being a high-viscosity poly(ethylene terephthalate) and the sheath portion being a low-viscosity poly(ethylene terephthalate).

Abstract: A composite substrate (10) is prepared for reinforcing a bituminous roofing material by securing together a carrier web (12) with a first set (14) of fiberglass rovings bundles and a second set (16) of fiberglass rovings bundles. The carrier web will have a pair of opposed planar surfaces. The web will define a machine direction and a cross machine direction for the substrate, with the first and second sets of rovings bundles each positioned in parallel relationship, with the longitudinal axes defined by the individual rovings of the two sets being in non-parallel relationship to each other when viewed normal to the plane of the web. The bundle sets are maintained in the spaced apart parallel relationships and the non-parallel angular relationship by the adhesive, stitching or other conventional method of securing which holds the substrate together. If a stitching machine is used, the preferred yarn (18) would be a polyester yarn.

Abstract: A device knits together a tubular structure of continuous fibers with a stitch yarn, to provide a reinforcing substrate, especially for use with roofing materials. The device brings together first and second sets of the continuous fibers at a cylinder with a plurality of latch needles. The first set of fibers enter the cylinder radially in interstitial spaces between adjacent needles. At least one continuous fiber constituting the second set of fibers enters the cylinder tangentially at an insertion point. Axial manipulation of the needles at the insertion point results in knitting the stitch yarn around the intersecting first and second continuous fibers, resulting in the knitted tubular structure. The manipulation is achieved by rotating the means by which the second fibers and the stitch yarn are introduced, as well as the means for manipulating the needles, in a stepwise sequential manner around the circumference of the cylinder.

Abstract: The invention provides apparatus for producing multi-axial non-woven fabric comprising an endless series of yarn guides (3) having upper and lower reaches which extend widthwise of the apparatus and which are driven in opposite directions, rotatable creel means (2) for supplying yarns (1) to the yarn guides (3), the creel means (2) being driven in the same direction and at substantially the same speed as the endless series of yarn guides (3), and stitching means (5) for stitching the yarns (1) laid by the endless series of yarn guides (3).