A shell core (1) configured for being incorporated in a shell of a fiber reinforced polymer composite structure wherein: the core has a first surface (2) and an opposite second surface (3), a first groove (4) is formed in the first surface (2) and divides the core into a first core part (5) and a second core part (6), the first groove (4) is defined by two opposing side walls (7a,7b) and a bottom (8), the distance T1 between the bottom (8) of the groove (4) and the second surface (3) of the core is of such a size that the core is flexible/bendable along the first groove, and the opposing walls (7a,7b) converge towards the bottom (8) forming an angle A1 of at least 45° with each other.

A fiber composite structure includes a base structure being formed of a first fiber composite material that includes first fiber bundles embedded in a first matrix material, wherein the base structure includes an opening defined by first fiber bundles which include first sections and a second section that continuously or uninterruptedly interconnects the first sections, wherein the second section forms a bay that defines a part of the circumference of the opening. The fiber composite structure further includes a functional structure positioned in the opening of the base structure and joined with the first fiber composite material of the base structure.

A method for forming a fiber-reinforced thermoplastic control surface may comprise: stacking plies of thermoplastic composite sheets to a first desired thickness to form a first skin; stacking plies of thermoplastic composite sheets to a second desired thickness to form a second skin; forming the first skin in a first contour; forming the second skin in a second contour; forming a stiffening member including a thermoplastic resin, the stiffening member including a shape having a plurality of peaks and troughs; assembling the stiffening member between the first skin and the second skin; and joining the stiffening member to the first skin and the second skin.

The provided articles and methods use a non-woven fibrous web containing 60-100 wt % of oxidized polyacrylonitrile fibers; and 0-40 wt % of reinforcing fibers having outer surfaces comprised of a polymer with a melting temperature of from 100° C. to 300° C. The non-woven fibrous web has an average bulk density of from 15 kg/m.sup.3 to 50 kg/m.sup.3, with the plurality of fibers substantially entangled along directions perpendicular to a major surface of the non-woven fibrous web. Optionally, the oxidized polyacrylonitrile fibers can have a crimped configuration. Advantageously, these articles can display a combination of low thermal conductivity, high tensile strength, and flame resistance.

The provided articles and methods use a non-woven fibrous web containing 60-100 wt % of oxidized polyacrylonitrile fibers; and 0-40 wt % of reinforcing fibers having outer surfaces comprised of a polymer with a melting temperature of from 100° C. to 300° C. The non-woven fibrous web has an average bulk density of from 15 kg/m.sup.3 to 50 kg/m.sup.3, with the plurality of fibers substantially entangled along directions perpendicular to a major surface of the non-woven fibrous web. Optionally, the oxidized polyacrylonitrile fibers can have a crimped configuration. Advantageously, these articles can display a combination of low thermal conductivity, high tensile strength, and flame resistance.

The present application discloses a method of making a preform for use in manufacturing a component made of a composite material. The method includes stitching fibers onto a film to form a fiber bed in a two-dimensional shape, removing the film from the fiber bed, and adjusting the fiber bed into a three-dimensional shape to form the preform.

Multilayer fibreglass fabric with stitching comprises various stitching processes. These stitching processes not only create poor-surface finish but also it reduces the mechanical strength and increases cost of process and machinery. Therefore, present disclosure proposes a method for bonding of multilayer fiberglass fabric without stitching which comprises: pre-processing (601) wherein a raw material is selected and assembled according to requirement or final product. Processing (602) wherein processes like pressure rolling and needle punching are carried out. Post-processing (603) wherein the output in winded up, cut and packed in pre-determined sizes and dispatched. In present disclosure various combinations of input material are possible according to customer requirements.

The present invention relates to an interlayer sheet for a spar cap comprising: a first fibre layer comprising a first plurality of fibres, having a first upper fibre surface and a first lower fibre surface, a second fibre layer comprising a second plurality of fibres, having a second upper fibre surface and a second lower fibre surface. The first fibre layer is arranged on top of the second fibre layer, such that the first lower fibre surface is in contact with the second upper fibre surface. The first fibre layer is of a different characteristic than the second fibre layer. Furthermore, the present invention relates to a spar cap for a wind turbine blade, comprising a plurality of pre-cured fibre-reinforced elements including at least a first pre-cured fibre-reinforced element and a second pre-cured fibre-reinforced element; and a number of interlayer sheets arranged between the plurality of pre-cured fibre-reinforced elements.

An apparatus for molding a part includes a plunger cavity, a plunger, and a mold cavity, wherein the plunger is oriented out-of-plane with respect to a major surface of the mold cavity, and first and second vents couples to respective first and second portions of the mold cavity. In a method, resin and fiber are forced into the mold cavity from a plunger cavity, and at least some of the fibers and resin are preferentially flowed to certain region in the mold cavity via the use of vents.

A composite structural panel for use in bridge structures, and method of manufacturing same, comprises a top panel and a bottom panel separated by and attached to at least one, but preferably a plurality, of structural composite preforms which may be fabricated by a continuous manufacturing process and may be saturated by resin using a continuous wetting process. The composite preforms may take any cross-sectional shape but are preferably trapezoidal. The top and bottom panels may be fabricated from a plurality of layers of woven fabric layers and non-woven fabric layers which are saturated with a resin that is subsequently cured using cure processes known in the art. The composite structural panel of the invention is usable as a flat structural member for use as bridge decking, ramps, trestles, and any application requiring a structural panel.