A thermoplastic product includes a fabric-based reinforcing sheet and a polymerized thermoplastic material. The fabric-based reinforcing sheet is wound about a mandrel to form a plurality of layers having a cross-sectional shape that corresponds to the mandrel. The fabric-based reinforcing sheet includes a plurality of fiber bundles, which may have a bidirectional orientation or configuration. A polymerized thermoplastic material is disposed within each layer of the fabric-based reinforcing sheet. The polymerized thermoplastic material bonds each layer of the fabric-based reinforcing sheet to an adjacent layer.

Process for forming a permanent join between two sections of fibrous material contained in a thermosetting resin matrix, said process comprising overlaying the two sections and subjecting the overlaid sections to ultrasonic welding to form a permanent join between the two sections, wherein there is no significant change in the sub-ambient Tg of the fibrous material contained in the thermosetting resin matrix in the region of the permanent join.

Process for forming a permanent join between two sections of fibrous material contained in a thermosetting resin matrix, said process comprising overlaying the two sections and subjecting the overlaid sections to ultrasonic welding to form a permanent join between the two sections, wherein there is no significant change in the sub-ambient Tg of the fibrous material contained in the thermosetting resin matrix in the region of the permanent join.

A method of fabricating a fiber structure by multilayer three-dimensional weaving between a plurality of weft yarns and of warp yarns, the fiber structure having at least first and second portions that are adjacent in the warp direction, the first portion presenting, in a direction perpendicular to the warp and weft directions, a thickness greater than the thickness of the second portion, includes making the first portion using a step of three-dimensionally weaving warp and weft layers in which a fiber fabric is formed in the form of a Mock-Leno weave grid in a core of the first portion together with skins at a surface of the first portion, a weave of the skins being modified locally so as to deflect certain warp yarns from said skins and weave them with the fiber fabric in the form of the Mock-Leno weave grid.

An electromagnetic coil with improved insulation properties at high temperatures. A bobbin is insulated by a thin ceramic composite layer that is produced by winding a glass or ceramic fiber over the support structure and impregnating it with a pre-ceramic polymer. The pre-ceramic polymer is then modified to form a ceramic SiO.sub.2 matrix around the fibrous layer. The ceramic matrix secures the glass or ceramic fibers in place and produces a dense layer. A ceramic coated magnet wire is then wound around the insulated support structure. The magnet wire is a conductor that is spiral-wrapped with a glass fiber impregnated with a pre-ceramic polymer.

A preform-charge fixture creates a preform charge, which is a partially consolidated assemblage of preforms that can be efficiently transferred to a mold to create a finished part in a molding process, such as compression molding. In the illustrative embodiment, the preform-charge fixture includes peripheral cleats that are movable towards a central cleat to create a small gap therebetween that receives and constrains preforms in a desired position. The fixture also includes clamps, which are operable to engage an uppermost layer of preforms in the gap and apply a slight amount of downward pressure thereto to assure that the preforms are properly seated. The fixture also accommodates an energy source that heats the preforms so that, in conjunction with downforce applied by the clamps and/or gravity, the preforms can be tacked together, forming the preform charge.

A preform-charge fixture creates a preform charge, which is a partially consolidated assemblage of preforms that can be efficiently transferred to a mold to create a finished part in a molding process, such as compression molding. In the illustrative embodiment, the preform-charge fixture includes peripheral cleats that are movable towards a central cleat to create a small gap therebetween that receives and constrains preforms in a desired position. The fixture also includes clamps, which are operable to engage an uppermost layer of preforms in the gap and apply a slight amount of downward pressure thereto to assure that the preforms are properly seated. The fixture also accommodates an energy source that heats the preforms so that, in conjunction with downforce applied by the clamps and/or gravity, the preforms can be tacked together, forming the preform charge.

A method is described for forming a body having at least one through-going passage, said method has the steps of: a) providing a mixture comprising particles and at least one liquid pocket inside a curable matrix, b) subjecting said mixture to a first alternating voltage having a first frequency to form a body in which said at least one liquid pocket extends from a first surface of said body to a second surface of said body thereby forming at least one through-going passage lacking curable matrix, and c) curing said curable matrix into a cured matrix, wherein at least some of said particles are located at an interface between said at least one through-going passage comprising liquid and said cured matrix.

Embodiments of the invention are directed to methods, devices, and compositions for 3D printing of piezoelectric devices. The piezoelectric devices can be used for sensor applications using poly(vinylidene) fluoride (PVDF) and BaTiO.sub.3 (BTO) nanocomposites through in-situ electric poling 3D printing process.

A pre-preg product, such as a tape or sheet suitable for forming a composite having reinforcement fibers and a liquid crystal thermoset (LCT) precursor is provided. Further aspects of the invention are directed to a method for preparation of the pre-preg product and to composite products based on the pre-preg product.