Abstract: Some embodiments of a compression mold for forming a rib-and-sheet part includes a mold cavity and a mold insert. A sheet is placed in the mold cavity, and the mold insert is placed on the sheet. A preform assemblage is placed in a gap that is formed between the mold insert and the wall of the mold cavity. A mold core is biased above the preform assemblage, prior to molding operations, via a compression spring.

Abstract: Rib-and-sheet structures include a rib comprising continuous, aligned fibers. The rib is fabricated via compression molding from continuous, aligned fiber, thereby providing an aligned, continuously reinforced rib. In one embodiment, rib-and-sheet structures are produced in a two-step compression-molding process, wherein a near net-shape rib is molded, in a first mold, from fiber-bundle based preforms, and then a rib-and-sheet part is molded by placing, in a second mold, the rib with either: (i) a preformed sheet, (ii) plies that form a laminate/sheet or (iii) chopped fibers that form a sheet during the molding process. In another embodiment, rib-and-sheet structures are fabricated in a one-step compression-molding process, wherein fiber-bundle-based preforms and (i) a preformed sheet, (ii) plies that form a laminate/sheet, or (iii) chopped fibers are combined in a single mold and molded in a single step.

Abstract: A hybrid preform comprises a bundle of unidirectionally aligned fibers, and at least one partial cut that extends part of the way, but not all of the way, through a transverse cross section of the bundle of fibers at least one location along the length of the bundle.

Abstract: 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.

Abstract: Method and apparatus for splaying fibers for the forming preform charges for the production of composite discs, and for the production of composite disc, wherein rotary compaction is applied to an appropriately arranged assemblage of preforms.

Abstract: A method and apparatus for the continuous fabrication of fiber-bundle-based and composite-tape based preforms and preform charges includes a mandrel about which a constituent material, which is maintained under tension, is wound. The tension is insufficient to fully consolidate the wound material.

Abstract: 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.

Abstract: A method for altering polymer properties for the molding of parts comprises exposing, to a scission-causing stressor, a region of a polymer form. The scission-causing stressor is controlled to achieve, in a relatively higher molecular-weight polymer at the region, an amount of scission that results in a reduction in the molecular weight of the relatively higher molecular-weight polymer, thereby forming a relatively lower molecular-weight polymer at the region.

Abstract: A system and methods are disclosed for producing compression-molded components having one or more desired characteristics with respect to one or more objectives. In accordance with one embodiment, a parameter space comprising a set of values of a parameter is defined, where the parameter corresponds to a property of fiber bundles, and where the set of values represents all possible values of the parameter in the parameter space. The parameter space is narrowed, and a statistical model is generated based on a sampling of the narrowed parameter space. A value of the parameter is selected based on the statistical model, and a bundle of fibers conforming to the selected value is produced. A component comprising the bundle of fibers is then manufactured using a compression-molding process.

Abstract: A compression molding method for creating fine, features having desired fiber-alignment patterns involves creating a pressure gradient in a mold cavity during the soak phase of the compression-molding process. In the illustrative embodiment, the gradient is created by movement of a structure, and results in a flow of nearby fiber and melted resin. This alters local, preexisting, non-random fiber alignments. The process imparts geometries to a part (the bulging features) that are not otherwise present on the mold surface.

Abstract: A method for forming fiber-reinforced composite parts via compression molding, particularly useful for forming parts that include off-axis, out-of-plane, or small, intricate features. In accordance with the method, non-flowing continuous fiber bundles and flowing continuous fiber bundles are placed in a mold, wherein the flowing continuous fiber bundles are disposed proximal to a minor feature. The non-flowing bundle has a length about equal to the length of a major feature of the mold. The flowing bundle has a length that is somewhat longer than the length of the minor feature. Under heat and pressure, resin softens and fibers from the flowing continuous fiber bundles flow into the minor feature.

Abstract: A method for making structural foam parts having continuous aligned fibers includes placing an assemblage of fiber-bundle-based preforms in an injection mold, creating a melt flow of resin and, optionally, short, loose fiber, and adding foaming agent to the melt flow. When the foaming agent/melt flow mixture is introduced into the injection mold, the foaming agent foams. The assemblage is structured and positioned so that fibers therefrom adopt a desired alignment and position in the final part. Structural foam fills the remainder of the volume of the part.

Abstract: Some embodiments of a compression mold for forming a rib-and-sheet part includes a mold cavity and a mold insert. A sheet is placed in the mold cavity, and the mold insert is placed on the sheet. A preform assemblage is placed in a gap that is formed between the mold insert and the wall of the mold cavity. A mold core is biased above the preform assemblage, prior to molding operations, via a compression spring.

Abstract: A method for designing fiber-composite parts in which part performance and manufacturing efficiency can be traded-off against one another to provide an “optimized” design for a desired use case. In some embodiments, the method involves generating an idealized fiber map, wherein the orientation of fibers throughout the prospective part align with the anticipated load conditions throughout the part, and then modifying the idealized fiber map by various fabrication constraints to generate a process-compensated preform map.

Abstract: A method useful for forming a composite part having regions in which fibers align with the principle stress vectors as well as regions having a randomized fiber alignment. To form the randomized fiber alignment, a preform cavity is formed in a preform arrangement, and the preform arrangement is molded in accordance with compression molding protocols to form a part.

Abstract: Methods and apparatus for additive manufactures of complex parts using co-aligned continuous fibers are disclosed. Filament subunits having complex shapes are fabricated and inserted into a mold cavity. The layup is compression molded to form a complex part having high tensile strength.

Abstract: A cartridge for storing and transporting fiber-bundle-based preform charges includes a plurality of cells arranged within the housing, wherein each cell is physically adapted to receive a preform charge and prevent it from moving therein as the cartridge is transported. In some embodiments, the cartridge and preform charges it conveys are serialized.

Abstract: 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.

Abstract: A preformer capable of simultaneously forming plural preforms includes a forming surface and source of heat. The forming surface includes guides to keep fiber bundles, the nascent form of the preforms, spaced apart and to maintain their cross-sectional dimension. In some embodiments, the preformer further includes a source of energy, and in some embodiments, the preformer includes a source of energy and a cooling source. A method for forming preforms is also disclosed.

Abstract: Methods and apparatus for additive manufactures of complex parts using co-aligned continuous fibers are disclosed. Filament subunits having complex shapes are fabricated and inserted into a mold cavity. The layup is compression molded to form a complex part having high tensile strength.