An apparatus for securing first and second skins to a core in a composite rotor blade includes an elongated member configured to be installed through a passage in the core of the composite rotor blade. The elongated member has a first end configured to be attached to an outer surface of the first skin and a second end configured to be attached to an outer surface of the second skin. The apparatus also includes a first patch configured to adhere the first end to the outer surface of the first skin, and a second patch configured to adhere the second end to the outer surface of the second skin such the elongated member extends from the outer surfaces of the first and second skins through the passage in the core.

The present disclosure generally relates to systems and methods for composites, including short-fiber films and other composites. In certain aspects, composites comprising a plurality of aligned fibers are provided. The fibers may be substantially aligned, and may be present at relatively high densities within the composite. For example, the composite may include substantially aligned carbon fibers embedded within a thermoplastic substrate. The composites may be prepared, in some aspects, by dispersing fibers by neutralizing the electrostatic interactions between the fibers, for example using aqueous liquids containing the fibers that are able to neutralize the electrostatic interactions that typically occur between the fibers. The liquids may be applied to a substrate, and the fibers may be aligned using techniques such as shear flow and/or magnetism. Other aspects are generally directed to methods of using such composites, kits including such composites, or the like.

Processes and material compositions are disclosed for applying polymer additive manufacturing to producing press dies, such as for sheet metal forming. As disclosed in various embodiments, material compositions comprise a thermoplastic, a first filler having low aspect ratio particles and a second filler having high aspect ratio. In at least one embodiment, composites according to the disclosed teachings have a compressive modulus greater than 3500 MPa and a compressive strength greater than 70 MPa, such that the composites have sufficient mechanical properties for press tooling and are amenable to extrusion-type additive manufacturing processes. In at least one embodiment, the use of the disclosed composites with additive manufacturing enables reduced overall mass of tooling by inclusion of voids inside the die.

A method for manufacturing a composite part reinforced with nanotubes, includes stacking a plurality of composite plies of prepreg and at least one composite ply integrating nanotubes, the at least one composite ply integrating nanotubes being positioned in an inter-ply space between two composite plies of prepreg, wherein the at least one composite ply integrating nanotubes is a ply having a thermoplastic component, the nanotubes being integrated in the thermoplastic component.

Provided is a resin molded body capable of increasing a flexural modulus. A resin molded body according to the present invention includes a urethane resin, long reinforcing fibers, an inorganic filler having an average particle diameter of 1 μm or more, and fine inorganic particles having an average particle diameter of 200 nm or less, a content of the fine inorganic particles being 0.06 parts by weight or more and 3.00 parts by weight or less with respect to 100 parts by weight of the urethane resin.

The present invention relates to multi-layered composite structures and to methods for the preparation thereof. The present multi-layered composite structures are light weight and capable of high load bearing making the present multi-layered composite structures especially suitable to be used as load bearing structures in, for example, automotive. Specifically, the present invention relates to methods comprising the steps of a) providing a mould for said multi-layered composite structure; b) layering said mould with two or more layers forming the outer surface of said multi-layered composite; c) filling said layered mould with a mixture comprised of non-expanded heat-expandable microspheres and closing said mould; and d) subjecting said closed mould to a temperature of 80° C. to 140° C. during 1 to 230 minutes thereby providing a relative pressure in said closed mould of 0.1 to 20 bar through expansion of said heat-expandable microspheres thereby forming a multi-layered composite structure in said mould with a foam enforced inner core and a multi-layered outer surface; and e) separating the multi-layered composite structure from said mould.

A thermoplastic surfacer for providing lightning strike protection to a composite component of an aircraft, methods of manufacturing the surfacer, and methods of applying the surfacer to a composite part. The thermoplastic surfacer includes a broadgood having an amorphous thermoplastic resin, one or more fillers embedded into the broadgood, and a lightning strike protection mesh or foil embedded into the broadgood. When applying the surfacer to a composite part of an aircraft, the method includes draping the surfacer on an at least partially unconsolidated composite part, consolidating the at least partially unconsolidated composite part by heating the part to a temperature at or above a melt temperature of a resins used in the part and in the surfacer, and filling at least one surface defect in the consolidated part using the amorphous thermoplastic polymer resin and milled fibers provided in the thermoplastic surfacer.

A flame retardant composition includes poly(carbonate-bisphenol phthalate ester) or a combination of poly(carbonate-bisphenol phthalate ester) and a poly(ester), an organophosphorous flame retardant present in an amount effective to provide 0.5-0.8 wt % of added phosphorous; 5-45 wt % of glass fibers; optionally, a poly(carbonate-siloxane); optionally, 0.01-10 wt % of a flame retardant sulfonate salt; optionally, 0.1-0.6 wt % of an anti-drip agent; and optionally, 0.01-10 wt % an additive composition, wherein the amount of the polymer component, the organophosphorous flame retardant, the glass fibers, and the optional components total 100 wt %; and wherein a molded sample of the flame retardant composition has a UL 94 rating of V0 at a thickness of 1.2 millimeter, preferably a CA UL 94 rating of V0 at a thickness 0.8 millimeter.

A method of extruding filament comprises the steps of cutting a bulk source material into pieces having size S.sub.1, performing a first extrusion pass comprising the steps of melting the pieces in an extruding device at a temperature T.sub.1 and extruding a first filament at an extrusion speed V.sub.1, and performing at least one additional extrusion pass k comprising the steps of cutting the first filament into pieces having size S.sub.k, melting the pieces in an extruding device at temperature T.sub.k, and extruding a final filament at an extrusion speed V.sub.k. A system for extruding filament is also described.

A bulk moulding compound comprising one or more cyanate ester, a catalyst, a filler and reinforcement fibres is provide, whereby the one or more cyanate ester is independently selected from a difunctional cyanate ester compound and/or a polyfunctional cyanate ester and mixtures of these cyanate esters. Furthermore, the catalyst is independently selected from the group consisting of 4,4′ methylene-bis(2,6-diethylaniline) (M-DEA), 4,4′-methylene-bis(3-chloro-2,6-diethyl¬aniline) (M-CDEA), aluminum(III)acetylacetonate, and mixtures thereof.