A method of preparing a continuous yarn from comingled discontinuous glass fiber and thermoplastic fiber is described. An exemplary yarn comprising comingled recycled glass fiber and acrylic fiber is described. Methods of preparing fiber-reinforced composite components from the yarn are also described. The fiber-reinforced composite components can be used in a variety of applications. In an exemplary application, the composite is used to provide component parts for a model rocket body and nosecone.

A method of forming an injection-bonded joint includes providing a first part and a second part having a second part upper edge and a second part lower edge, and forming a chamber wall within a bondline region between mating surfaces of the first part and the second part. The chamber wall divides a bondline length of the bondline region and defines at least one adhesive chamber. The method further includes forming a bondline dam along each of the second part upper edge and the second part lower edge in a manner such that the chamber wall, the bondline dams, and the mating surfaces collectively enclose the adhesive chamber having a chamber upper edge and a chamber lower edge. The method also includes injecting a structural adhesive into the adhesive chamber through an injection port and discharging excess adhesive from the adhesive chamber through a bleed hole.

A propulsion chamber for a liquid propellant rocket engine is provided. The propulsion chamber includes an inside wall made of metal, an outside covering made of organic matrix composite material, and a cooling circuit arranged between the outside covering and the inside wall. The propulsion chamber further includes at least a first axial endpiece secured to the metal inside wall and presenting at least one radial protrusion received in a concave recess in an inside face of the outside covering. The concave recess is situated axially between first and second belts of reinforcing fibers oriented substantially circumferentially in the outside covering in such a manner as to take up forces associated with inside pressure and thrust.

The present invention generally relates to a system and method for using a volatile organic compound (VOC) free low radiant flux LED UV curable composition, and more particularly to unique and novel uses of the composition such as one or two or more of a fire retardant, clear coat, composite material, resin, top coat, improved holdout coating, a sealant coat, and combinations of the same.

The present invention generally relates to a system and method for using a volatile organic compound (VOC) free low radiant flux LED UV curable composition, and more particularly to unique and novel uses of the composition such as one or two or more of a fire retardant, clear coat, composite material, resin, top coat, improved holdout coating, a sealant coat, and combinations of the same.

For producing a dome-shaped element (2) provided with thermal protection for a solid propellant rocket engine, a coupling annular body (4) is arranged in a mold (5) and has a surface (20) that is clean and activated, by an atmospheric-pressure plasma treatment, before depositing a primer layer (26) and an adhesive layer (27) on the surface (20); ablative material is then automatically applied to the adhesive layer and to an area (17) of the mold (5) so as to form a series of superimposed layers (30).

The present invention introduces the use of a carbon nanotube-based material in the production of phased array patch antennas of various shapes and sizes including slot and spiral patch antennas. The use of this material provides the ability for the antennas to withstand high-intensity shock vibrations and other intense disturbances and continue emitting phased array signals. Furthermore, the use of this material for patch antennas allows for the alteration of the desired frequency and directional degree of interest by simply energizing various elements within the carbon nanotube-based material.

Fluted core sandwich panels are joined together to form a composite structure. Variations in panel ends are accommodated by a core stiffener insert installed in a joint between ends of the panels.

A method of additively manufacturing propellant elements, such as for rocket motors, includes partially curing a propellant mixture before extruding or otherwise dispensing the material, such that the extruded propellant material is deposited on the element in a partially-cured state. The curing process for the partially-cured extruded material may be completed shortly after the material is put into place, for example by the material being heated at or above its cure temperature, such that it finishes curing before it fully cools. The propellant material may be prepared by first mixing together, a fuel, an oxidizer, and a binder, such as in an acoustic mixer. After that mixing a curative may be added to the mixture. The propellant mixture may then be directed to an extruder (or other dispenser), in which the mixture is heated to or above a cure temperature prior to the deposition, and then deposited.

A hybrid rocket solid fuel grain having a cylindrical shape and defining a center port is additive manufactured from a compound of thermoplastic fuel and passivated nanocomposite aluminum additive. The fuel grain comprises a stack of fused layers, each layer formed as a plurality of fused abutting concentric circular beaded structures arrayed to define a center port. During operation, an oxidizer is introduced along the center port, with combustion occurring along the exposed port wall. Each circular beaded structure defines geometry that increases the surface area available for combustion. As each layer ablates the next abutting layer, exhibiting a similar geometry, is revealed, undergoes a gas phase change, and ablates. This process repeats and persists until oxidizer flow is terminated or the fuel grain material is exhausted. To safely achieve this construction, a fused deposition additive manufacturing apparatus, modified to shield the nanocomposite material from the atmosphere, is used.