초록 ▼

An improved warp/knit stitch reinforced multi-axial non-crimp layered fabric sheet used in structural applications, as for example, in aircraft and water applications, e.g. the skin of an airplane wing or fuselage structure, in water applications, e.g. skins of surfboards and boats, and in other are

An improved warp/knit stitch reinforced multi-axial non-crimp layered fabric sheet used in structural applications, as for example, in aircraft and water applications, e.g. the skin of an airplane wing or fuselage structure, in water applications, e.g. skins of surfboards and boats, and in other areas where high strength and relatively light weight is required. The fabric is comprised of a plurality of plies facewise disposed upon one another and knitted or stitched to form a structural sheet. Each fabric ply is made of strands of aligned structural fibers which can be later impregnated and even pre-impregnated with a resin curable matrix. The improved sheet is formed by applying unidirectional non-crimp and non-woven plies of different angular relationship to one another, e.g. a +45.degree., a 90.degree. and a -45.degree. ply and locating 0.degree. plies in essentially any position in the ply arrangement such that the 0.degree. ply can be on the bottom of the sheet, on top of the sheet, or interposed between plural ply layers of the sheet. The sheets are then knitted or stitched together to make a stack of multi-axial fabric layers. The fiber weight and thickness can also be varied throughout the sheets by using plies of different thicknesses or differing weights of fibers. Moreover, the percentage of a certain type of fiber in a particular ply can be varied. In addition, damage tolerance can be built into the cured laminate. Further, doublers and local area reinforcements can also be included in the sheet. In addition, a warp/knit, or warp/stitched fabric may be made to a desired width without otherwise affecting the structural properties of the sheet. An apparatus and a method for producing the fabric sheets is also disclosed.

대표청구항 ▼

[ Having thus described the invention, what we desire to claim and secure by Letters Patent is:] [1.] A warp/knitted multi-ply structural fabric sheet which is non-woven and non-crimped and capable of being used in structural applications, said fabric sheet being comprised of:a) a plurality of plies

[ Having thus described the invention, what we desire to claim and secure by Letters Patent is:] [1.] A warp/knitted multi-ply structural fabric sheet which is non-woven and non-crimped and capable of being used in structural applications, said fabric sheet being comprised of:a) a plurality of plies other than 0.degree. plies disposed upon one another, each ply being formed of parallel non-overlapping fibers laid side-by-side, and the fibers in one of said plies being oriented at an angle to the fibers in one of the other plies;b) a 0.degree. pre-stabilized ply located in said fabric sheet other than on an upper surface thereof, the 0.degree. pre-stabilized ply being formed of parallel non-overlapping 0.degree. fibers laid side-by-side and joined together by an additional joining material prior to the 0.degree. pre-stabilized ply being placed in facewise engagement with another of the plies, so as to substantially retain the parallel non-overlapping relation of the 0.degree. fibers during manipulation of the 0.degree. pre-stabilized ply; andc) a thread stitched through the plies to warp/knit the plies together into a structural fabric sheet.