Abstract: Provided is composite carbon fibers in which polymers having an amino containing group are covalently bonded to the surface of the carbon fiber. Aspects are also directed to processes for preparing the composite carbon fibers. Additional aspects are directed to reinforced composites comprising a resin matrix and the composite carbon fibers, and to processes of making such reinforced composites.

Abstract: A method of analytically determining a laser power for laser sintering includes choosing a batch of powder material for building a plurality of test rods; selecting a range of laser power for building the test rods; determining a plurality of power increments within the selected range to define a plurality of laser power settings; programming a laser sintering machine to build at least one test rod at each laser power setting; constructing the test rods; wherein the optimal power is at least one watt below a lowest laser power setting associated with the formation of voids; identifying the laser power setting used to construct a respective test rod without formation of voids in the surface as an optimal laser power; and configuring the selective laser sintering machine with the optimal laser power when conducting a laser sintering process using the chosen batch of powder material.

Abstract: A process for preparing a feedstock having polyaryletherketone particles for using in selective laser sintering. The process includes the steps of determining a particle size distribution of the polyaryletherketone particles in the feedstock based on a number of particles corresponding to each of a plurality of particle size ranges to obtain a particle size distribution determination. The process further includes the step of reducing the number of particles in the feedstock corresponding to one or more size ranges having a depressed melting temperature relative to the average melting temperature of the polyaryletherketone particles in the feedstock based on the particle size distribution determination.

Abstract: A semipreg that can be cured/molded to form aerospace composite parts including rocket booster casings. The semipreg includes a fibrous layer and a resin layer located on one side of the fibrous layer. The resin layer includes an epoxy component that is a combination of a hydrocarbon epoxy novolac resin and a trifunctional epoxy resin and optionally a tetrafunctional epoxy resin. The resin matrix includes polyethersulfone as a toughening agent and a thermoplastic particle component.

Abstract: A method of producing an object from a polymer powder using a laser sintering system, whereby the laser sintering system introduces heat energy to solidify select points of a layer of polymer powder according to build data of the object and adjusts the heat energy according to solidification of select points of other layers.

Abstract: There is provide a process for unwinding material from a spool (2) wherein the angle (?) of take off at the first contact point (4) for the unwind is always in the range 0±20°, and wherein the first contact point (4) for the unwind is no more than 600 mm from the axis (3) of rotation of the spool (2). There is also provided an apparatus for the unwinding of material from a spool (2) comprising an axis (3) upon which a spool (2) may be rotatably mounted and a static first contact point (4) for the unwound material positioned no more than 600 mm from the centre of the axis (3), wherein the angle (?) of take off at the first contact point (4) for the unwind is always in the range 0±20°.

Abstract: Pre-impregnated composite material (prepreg) that can be cured/molded to form aerospace composite parts. The prepreg includes carbon reinforcing fibers and an uncured resin matrix. The resin matrix includes an epoxy component, polyethersulfone as a toughening agent, and a curing agent. The resin matrix is also composed of a thermoplastic particle component that includes hybrid polyamide particles wherein each hybrid particle contains a mixture of amorphous and semi-crystalline polyamide.

Abstract: A system for inspecting a part while said part is produced by additive manufacturing, includes an additive manufacturing apparatus having a build tray, the apparatus being configured to fabricate the part layer-by-layer on the tray; an automated tool holder carrying a tool configured to deposit, add or weld layer-upon-layer of material; the tool holder and tray are configured to move relative to one another along a defined path; and an inspection device attached to the tool holder and configured to scan a layer of material in situ. The tool holder alternately arranges the tool and inspection device in a working position so that the tool holder fixes the tool in the working position for depositing, adding, or welding the layer of material and thereafter the tool holder switches said tool with the inspection device into the working position for scanning and detecting defects in the layer of material.

Abstract: A powder composition suitable for use in selective laser sintering for printing an object. The powder composition includes a first fraction including a plurality of polyaryletherketone (PAEK) particles having a mean diameter less than 30 microns, a second fraction having a plurality of polyaryletherketone (PAEK) particles having a mean diameter greater than 30 microns, and a third fraction having a plurality of carbon fibers. The first fraction and the second fraction are formed by an air classification separation performed on a pulverized powder. After the separation, the first fraction, the second fraction, and the third fraction are blended in a high intensity mixer. The powder composition when used in selective laser sinter results in parts with increased tensile strength and reduced surface roughness, among other improvements, as compared to similar powders omitting the first fraction. The PAEK may include polyetherketoneketone (PEKK).

Abstract: A powder composition suitable for use in laser sintering for printing a three-dimensional object. The powder composition includes a polyaryletherketone (PAEK) powder having a plurality of particles. The plurality of particles having a mean diameter of D50. The composition includes a plurality of carbon fibers having a mean length L50. L50 is greater than D50. The particles are substantially non-spherical. A portion of the carbon fiber is embedded into the particle via high intensity mixing.

Abstract: Acoustic structures in which acoustic septa are located in the cells of a honeycomb for reducing the noise generated from a source. The honeycomb used to form the acoustic structure has walls that contain convex and concave contours which make the honeycomb flexible. The acoustic septa are formed by inserting planar acoustic inserts into the honeycomb cells to form a septum cap which is friction-locked within the cell and then permanently bonded in place. The planar acoustic septum is configured to match the unique shape of the cell contours to provide desired friction-locking when inserted into the cells and desired acoustic properties after being permanently bonded in place.

Abstract: A powder composition suitable for use in selective laser sintering for printing an object. The powder composition includes a first fraction comprising a plurality of polyaryletherketone (PAEK) particles having a mean diameter less than 30 microns, a second fraction comprising a plurality of polyaryletherketone (PAEK) particles having a mean diameter greater than 30 microns, and a third fraction comprising a plurality of carbon fibers. The first fraction and the second fraction are formed by an air classification separation performed on a pulverized powder. After the separation, the first fraction, the second fraction, and the third fraction are blended in a high intensity mixer. The powder composition when used in selective laser sinter results in parts with increased tensile strength and reduced surface roughness, among other improvements, as compared to similar powders omitting the first fraction. The PAEK may include polyetherketoneketone (PEKK).

Abstract: The filament count of a carbon fiber tow is increased by spreading and commingling the carbon filaments of a first tow with the carbon filaments of a second tow. The carbon filaments of the first and second tows are spread apart using a gas stream. The spread tows are aligned with each other and brought into contact as they pass over a grating in the presence of the same or a different gas stream to form an entangled tow. The entangled tow is then formed into a combined tow. The modulus and denier of the carbon filaments in the first and second tows may be the same or they can be varied to provide combined tows with a wide range of filament counts and filament combinations.

Abstract: An acoustic honeycomb panel is plugged with an acoustic honeycomb plug. The acoustic honeycomb plug is adhesively bonded in the panel using a honeycomb seam. The honeycomb seam is composed of a honeycomb support that is located within the seam channel and an adhesive. Using honeycomb seams to adhesively bond acoustic honeycomb plugs into acoustic honeycomb panels is useful in repairing damaged areas of acoustic honeycomb panels that are located in the acoustic treatments for jet engines.

Abstract: Method for producing an object by additively manufacturing a preform of the object from a building material comprising a polymer. The preform is encapsulated with a metal or metal alloy encapsulant that is capable of withstanding temperatures greater than the preform. The encapsulated preform is heated at a predetermined temperature and for a period of time, such that the preform at least partially transmutes into the form of a carbonaceous solid.

Abstract: Acoustic structures in which acoustic septa are located in the angled cells of a honeycomb for reducing the noise generated from a source. The honeycomb used to form the acoustic structure has cell walls that extend at an angle relative to the honeycomb edges such that the depth of the honeycomb cells is greater than the honeycomb core thickness The acoustic septa are formed by inserting planar acoustic inserts into the angled honeycomb cells to form septum caps which are friction-locked within the angled cells and then permanently bonded in place.

Abstract: Pre-impregnated composite material (prepreg) that can be cured/molded to form aerospace composite parts that are designed to tolerate hot and wet conditions. The prepreg includes fibers and an uncured resin. The uncured resin includes an epoxy component that is a combination of a trifunctional epoxy resin, a tetra functional epoxy resin and a solid epoxy resin. The resin includes polyethersulfone and a thermoplastic particle component. The uncured resin also includes a curing agent.

Abstract: A process for manufacturing a three-dimensional object from a powder by selective sintering the powder using electromagnetic radiation. The powder includes recycled PAEK. In one embodiment, the powder includes recycled PEKK. In one embodiment, the powder includes first recycle PEKK and second recycle PEKK. In one embodiment, the powder consists essentially of recycled PEKK. The process may include the step of maintaining a bed of a selective laser sintering machine at approximately 300 degrees Celsius and applying a layer of the powder to the bed. The average in-plane tensile strength of the three-dimensional object is greater than that of a three-dimension object manufactured by selective sintering using a powder including an unused PEKK powder.

Abstract: Provided is a composition for the treatment of fibers, such as PAN precursor fibers. The finish composition includes a polysiloxane; an emulsifier; water; and a dicarboxylic acid having a pKa from 1 to 4, and boiling point from 200 to 400° C. The dicarboxylic acid may have the following formula: where R1 is absent or a saturated or unsaturated, linear or branched, aromatic substituted or unsubstituted, hydrocarbon group; Y1 and Y2 are independently hydrogen, nitrogen, oxygen, sulfur, phosphorus, C1-C6 alkyl group, or an alkoxy group; and X1 and X2 are independently one or more hydrogen atoms, a metal, a quaternary amine, or a hydrocarbon group having up to 6 carbon atoms, the hydrocarbon group being an alkyl group, an alkylene group, or an aromatic group, which may be branched or linear, and may optionally have one or more heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur and phosphorus.

Abstract: A thermal panel having a high temperature side located nearest a source of heat and a low temperature side. The thermal panel includes a corrugated composite material core having hot side ridges and cold side ridges. A hot side skin is attached to the hot side ridges to form a plurality of first cells. A cold side skin is attached to the cold side ridges to form a plurality of second cells. The first cells and second cells are substantially filled with an insulating material that has a thermal conductivity which is lower than the thermal conductivity of the composite material.