Pre-consolidated charges of chopped fibers for composite component manufacturing

Abstract

The present invention relates to a pre-consolidated charge of chopped fibers for composite component manufacturing. One embodiment is a method for manufacturing a composite component. The method includes: reducing the volume factor of a fragment of chopped fibers when forming the fragment into a pre-consolidated charge; forming a portion of the pre-consolidated charge into a formed volume charge that fits within a die; and compression molding the formed volume charge within the die.

Description

Technical Field

[0001] The present disclosure relates to the field of composite materials, and in particular to the manufacture of composite parts. Background Art

[0002] "Chopped fibers" is a term referring to small pieces of discontinuous fibers reinforced by a thermoplastic resin. Each piece is relatively small (e.g., less than ten inches wide) and includes short fiber segments. When the pieces of chopped fibers are heated to melting temperature and subjected to pressure, the thermoplastic between the pieces mixes, producing a single composite part reinforced by randomly oriented short fibers.

[0003] The sheets of chopped strands can be prepared by chopping up waste composite parts that would otherwise be discarded, or sheets can be cut to specific sizes from unidirectional prepreg tapes. The resulting sheets of chopped strands have a significant amount of volume. That is, when the sheets of chopped strands are stacked into a die for molding, the sheets are separated by air gaps.

[0004] It would therefore be desirable to have a method and apparatus that takes into account at least some of the above-mentioned issues as well as other possible issues. Summary of the invention

[0005] The embodiments described herein utilize compression molding to make a solid charge of chopped fibers for placement into a die. The solid charges have no air gaps and are shaped to fit into the die in which they will be placed. Therefore, the solid charges take up less space than loose sheets of chopped fibers, allowing the compression molding die to be smaller. Additionally, the solid charges are not separated by air gaps and will melt significantly faster than stacked sheets of chopped fibers.

[0006] One embodiment is a method for manufacturing a composite component, the method comprising: reducing the volume factor of chopped fiber fragments when forming the fragments into a pre-consolidated charge; forming a portion of the pre-consolidated charge into a formed volume charge that fits within a die; and compression molding the formed volume charge within the die.

[0007] Another embodiment is a non-transitory computer-readable medium containing programming instructions, which, when executed by a processor, are operable to perform a method for manufacturing a composite component, the method comprising: reducing the volume factor of fragments of chopped fibers when forming the fragments into a pre-consolidated charge; forming a portion of the pre-consolidated charge into a formed volume charge that fits within a die; and compression molding the formed volume charge within the die.

[0008] Another embodiment is a system for manufacturing a composite part. The system includes a mold that preconsolidates fragments of chopped fibers including discontinuous fibers and thermoplastic into a preconsolidated charge having a volume factor between 1 and 2; a female compression molding die having a socket defining a shape of the composite part; a male compression molding die having a protrusion complementary to the socket; and a shaped volume charge of preconsolidated chopped fibers manufactured from the preconsolidated charge, the shaped volume charge being disposed within the socket and flush against at least one wall of the socket.

[0009] Yet another embodiment is an apparatus for facilitating the manufacture of a composite part. The apparatus includes a mold including: a plurality of walls; and a recess surrounded by the walls, the recess receiving a fragment of chopped fibers including discontinuous fibers and a thermoplastic. The apparatus also includes a press sized to complement the mold.

[0010] Yet another embodiment is an article comprising a bulk formed charge comprising discontinuous fibers melted from fragments of chopped fibers and a thermoplastic shaped to be positioned against a wall of a socket of a compression molding die.

[0011] Other illustrative embodiments (e.g., methods and computer-readable media related to the foregoing embodiments) may be described below. The features, functions, and advantages that have been discussed may be implemented independently in various embodiments, or may be combined in other embodiments, further details of which may be seen with reference to the following description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Some embodiments of the present disclosure will now be described by way of example only and with reference to the accompanying drawings. The same reference number represents the same element or the same type of element throughout the drawings.

[0013] Figure 1 is a diagrammatic representation of a molding apparatus for making a preconsolidated charge of chopped fibers in an illustrative embodiment.

[0014] FIG. 2A to FIG. 2B is a flow chart showing a method for producing a pre-consolidated charge of chopped fibers and using them to fabricate a composite part in an illustrative embodiment.

[0015] Figure 3 to Figure 4 is a diagram showing pressure development of a pre-consolidation charge in an illustrative embodiment.

[0016] Figures 5 and 6 The forming of the pre-consolidated charge into a desired shape is shown in an illustrative embodiment.

[0017] Figure 7The insertion of a forming volume charge into a compression molding die is shown in an illustrative embodiment.

[0018] Figures 8 to 9 A forming volume charge disposed at a compression molding die is shown in an illustrative embodiment.

[0019] Fig.10 is a block diagram of a composite manufacturing system in an illustrative embodiment.

[0020] Fig.11 is a flow chart of an aircraft production and service methodology in an illustrative embodiment.

[0021] Fig.12 is a block diagram of an aircraft in an illustrative embodiment. DETAILED DESCRIPTION

[0022] The accompanying drawings and the following description provide specific illustrative embodiments of the present disclosure. Therefore, it will be understood that those skilled in the art will be able to design various arrangements that, although not explicitly described or shown herein, embody the principles of the present disclosure and are included within the scope of the present disclosure. In addition, any embodiments described herein are intended to help understand the principles of the present disclosure and are to be interpreted as not being limited to such specifically described embodiments and conditions. Therefore, the present disclosure is not limited to the specific embodiments or embodiments described below, but is defined by the claims and their equivalents.

[0023] Figure 1 1 is an illustration of a molding apparatus 100 for making a pre-consolidated charge of chopped fibers (including thermoplastic resin and fibers) in an illustrative embodiment. The molding apparatus 100 includes a mold 120 and a press 110. The mold 120 includes a wall 128 having a lip 122 and a base 126, which together define a recess 124 in which a fragment 130 of chopped fibers is disposed. The fragment 130 may be obtained by chopping (e.g., cutting small solid pieces from) a component 132 (e.g., a composite component) or by making pre-cut pieces (e.g., pre-impregnated unidirectional tape) from the component 132. In such an embodiment, the fragment 130 of chopped fibers thus comprises a portion of the chopped composite component (i.e., component 132).

[0024] Thus, the fragments 130 may include flat flakes, rough volume flakes, etc. The press 110 is sized to complement the mold 120 and is driven into the recess 124 at high pressure and temperature to produce a pre-consolidated charge. The fragments 130 may exhibit a considerable volume factor (e.g., between 5 and 10) when stacked in the recess 124. As used herein, "volume factor" refers to the ratio of the volume of the fragments of chopped fibers to the volume of the fragments of the same weight of chopped fibers after consolidation into a void-free solid. Therefore, most of the space within the recess 124 may include air gaps 134 that insulate the fragments 130 from heat. This may increase the time required to melt the thermoplastic within the fragments by a considerable amount (e.g., ninety minutes or more, even when pressure is applied). However, after the pre-consolidated charge has been consolidated, it can be used for compression molded parts. Since the pre-consolidated charge has no air gaps, it heats much faster (e.g., ten times faster or more) than loose fragments. When the molding apparatus 100 is operated to produce a pre-consolidated charge for a large volume of chips 130 (e.g., a volume that is twice or more the amount of chopped fibers required to fill a die for compression molding), then the total amount of time consumed in the manufacturing process is reduced. Specifically, performing a single isolated delayed heating process at the molding apparatus 100 followed by multiple accelerated heating processes in a compression molding system is much faster than performing multiple isolated delayed heating processes in a compression molding system.

[0025] About FIG. 2A to FIG. 2B Illustrative details of the operation of the molding apparatus 100 are discussed. For this embodiment, it is assumed that the molding apparatus 100 is empty and currently awaiting loading in order to manufacture a pre-consolidated charge of chopped fibers. The thermoplastics within the chopped fibers may include polyetheretherketone (PEEK), polyaryletherketone (PAEK), polyphenylene sulfide (PPS), nylon, and the like.

[0026] Figure 2A is a flow chart showing a method 200 for making a pre-consolidated charge of chopped fibers and using them to make a composite part in an illustrative embodiment. Figure 2A A broad overview of the approach is provided, but Figure 2B Additional and detailed descriptions of the steps within the method are provided.

[0027] Steps of method 200 Figure 1 The method 200 is described with reference to the molding apparatus 100 of the present invention, but those skilled in the art will appreciate that the method 200 may be performed in other systems. The steps of the flowchart described herein are not all inclusive and may include other steps not shown. The steps described herein may also be performed in an alternative order.

[0028] In step 202, a pre-consolidated charge having a volume factor between 1 and 2 (e.g., a volume factor between 1.1 and 1) is formed. The pre-consolidated charge can be formed by heating and pressing together loose pieces of chopped fibers in a molding apparatus 100 as described above. For example, in one embodiment, the entire molding apparatus 100 and the pieces of chopped fibers 130 are heated in an oven until the thermoplastic melts, enter a press, are pressed, and cooled. In another embodiment, the mold 120 and press 110 are heated in place, the thermoplastic in the pieces becomes molten by indirect heat from the mold 120, and the press 110 is closed. In another embodiment, the mold 120 is heated, and an IR convection element (not shown) is placed above the mold 120 to melt the thermoplastic in the pieces 130, then the mold 120 is moved to the press 110, the heater is shuttled out of the press, and the press is closed. If desired, the chopped fibers and / or chips of the molding device 100 may be preheated prior to loading the added chips.

[0029] After the pre-consolidation charge has been formed, the pre-consolidation charge may be further inspected to ensure that no foreign matter is present therein. For example, the pre-consolidation charge may be inspected via ultrasound or visual techniques.

[0030] In step 204, portions of the pre-consolidated charge are formed into a formed volume charge that fits within a female compression molding die. The forming process may include punching or cutting a plurality of pieces from the pre-consolidated charge, each piece being designed to fit within a socket of a female compression molding die. For example, Figures 5 and 6 As shown, a portion 500 of a pre-consolidated charge 400 may be trimmed, stamped, or otherwise formed into a plurality of formed volume charges 600. The volume of each formed volume charge 600 is equal to the volume of the composite part to be made therefrom.

[0031] In step 206, the forming volume charge is compression molded in the female compression molding die. For example, this may include driving the male compression molding die into the female compression molding die. The driving is performed while the forming volume charge is disposed in the recess of the female compression molding die. In addition, the driving is performed at a compression molding pressure and temperature (as described above).

[0032] Figure 2B The method 250 provides a description of Figure 2AIn step 252, the fragments 130 of chopped fibers including discontinuous fibers (e.g., glass fibers, carbon fibers) and thermoplastics are placed at the mold 120. The thermoplastics in the chopped fibers may include polyetheretherketone (PEEK), polyaryletherketone (PAEK), polyphenylene sulfide (PPS), nylon, etc. Step 252 may include pouring a predetermined mass of the fragments 130 into the mold 120. The placement action may be performed, for example, by an automatic dispenser or a robotic arm (not shown).

[0033] In step 254, the volume factor of the chopped fiber fragments is reduced while the fragments are formed into a pre-consolidated charge. For example, heat can be applied and then the press 110 can be activated. The press 110 applies a compaction pressure P (e.g., a pressure between 20 pounds per square inch and 500 pounds per square inch) and heat (e.g., a temperature above the melting point of the thermoplastic and below the degradation temperature of the thermoplastic, e.g., between 600 and 800 degrees Celsius) to the recess 124, as shown in FIG. Figure 3 As shown. In one embodiment, reducing the volume factor includes applying a pressure between 20 pounds and 5000 pounds per square inch to the fragments of chopped fibers. Although the fragments 130 are separated by air gaps, over time, the fragments 130 are melted into a single mass of chopped fibers. When consolidated, the mass forms a pre-consolidated charge having a volume factor of less than 2 (e.g., a volume factor of 1, corresponding to no air pockets, or a volume factor of 1.1, corresponding to very few air pockets). In a specific embodiment, reducing the volume factor includes applying a pressure that reduces the volume factor of the fragments of chopped fibers 130 from greater than 5 to less than 2. Figure 4 The pre-consolidated charge 400 is shown residing within the recess 124 after molding is complete. Thus, the application of heat and pressure causes the pieces of thermoplastic to plastically deform into a pre-consolidated charge that conforms to the mold.

[0034] In step 256, the pre-consolidated charge 400 is removed from the mold 120. In step 257, a portion 500 of the pre-consolidated charge is formed into a formed volume charge that fits within the socket of the compression molding die. The formed volume charges have the same mass as the final composite part they will be compression molded to form. The forming process may include punching or cutting a plurality of pieces from the pre-consolidated charge, each piece being designed to fit within the die. For example, as Figures 5 and 6 As shown, the pre-consolidation charge 400 may be trimmed, stamped or otherwise formed for a plurality of formed volume charges 600. The mass of each formed volume charge 600 is equal to the mass of the composite part to be made therefrom.

[0035] As the number of forming volume charges 600 formed from the pre-consolidated charge 400 increases, greater benefits are achieved in manufacturing speed. That is, when there are enough forming volume charges 600 to facilitate multiple compression molding runs at the compression molding die, the total amount of time spent melting the chips 130 during manufacturing decreases.

[0036] In step 258, the forming volume charge 600 is disposed at the socket of the die that is made to be consistent therewith. As used herein, the forming volume charge 600 "fitted in" the socket does not need to completely fill the entire volume of the socket, because compression molding will enable the forming volume charge to achieve this result. On the contrary, if the forming volume charge does not protrude from the socket when the forming volume charge is placed in the socket, the forming volume charge is considered to be fitted in the socket. In a further embodiment, the forming volume charge is placed flush against one or more walls of the socket. In other embodiments, the forming volume charge 600 is precisely fitted in the socket, but the socket changes shape later during the compression molding process, or the final shape of the resulting composite part is at least partially defined by the male die. This arrangement increases the conductive heating of the forming volume charge during compression molding. Figure 7 The forming volume charge 600 is shown placed into the socket 702 of the female die 700 for compression molding. The socket 702 includes an axis 704, which is shaped according to the desired form for the resulting composite component. For example, the axis 704 can facilitate the insertion of the resulting composite component into another composite component. The axis 704 can also be used to accommodate a pull-out pin or piston (not shown), which facilitates the resulting composite component to be pushed out after the resulting composite component hardens. In this embodiment, the forming volume charge moves along direction 710 and is located flush against the wall 706. Therefore, the forming volume charge 600 is placed in the disc-shaped portion of the socket 702, but does not enter the axis 704 of the socket 702. Figure 8 The formed volume charge 600 is shown inserted into the socket 702.

[0037] In step 260, the forming volume charge 600 is melted into molten chopped fibers via the application of heat. Because the forming volume charge 600 has no air gap, it is not isolated from heat. This means that conductive heat transfer (e.g., from the female die 700) and radiant heat transfer (e.g., from an infrared lamp or other heating element) apply heat directly to the thermoplastic within the forming volume charge, thereby reducing the amount of time to melt by a factor of ten to one, or even more. Therefore, the cycle time of the female die 700 is reduced, and composite parts can be manufactured more quickly. Further, when compared to other female dies that utilize fragments of chopped fibers, the size of the female die 700 can be reduced because the socket size of the female die 700 is determined to accommodate a low volume factor (e.g., between 1 and 2), while other female dies will have to accommodate a high volume factor (e.g., between 5 and 7).

[0038] In step 262, the molten chopped fibers are compression molded into a shape defined by the socket. Because the molten chopped fibers have a low viscosity, and because the shape of the socket may be complex, the molten chopped fibers will not flow completely into the socket without applying pressure and heat. The amount of pressure applied during molding may depend on the geometry and distance over which the chopped fibers flow. That is, more complex geometries and greater flow distances may require higher pressures and / or pressures. The amount of pressure used during this compression molding process may be between 20 pounds per square inch and 5000 pounds, and the temperature may be greater than the melting temperature of the thermoplastic in the chopped fibers, but lower than the degradation temperature of the thermoplastic. Fig. 9 (which corresponds to Figure 8 9) provides an embodiment in which a male die 900 having a protrusion 910 is pressed against the forming volume charge 600 in a direction 920 as the forming volume charge 600 melts so as to drive the molten thermoplastic into the shaft 704. In this embodiment, the die includes an integral heater 930 that facilitates heating during the compression molding process to prevent the thermoplastic from solidifying / hardening before the entire die cavity is filled.

[0039] In step 264, the molten chopped fibers are cooled into a composite part. The cooling process can be performed passively, or actively by drawing a cooling fluid (e.g., air, water) through the female die 700. After the composite part has been formed, it can be removed and the female die 700 can be reloaded with more forming volume charges made from the pre-consolidated charge 400.

[0040] Methods 200 and 250 provide a technical benefit over existing systems and techniques because it prevents time-consuming operations associated with melting pieces of chopped fibers from having to be performed each time compression molding occurs. Instead, a large pre-consolidated charge can be made that provides material for multiple repeated compression moldings. This reduces the total amount of time spent melting the pieces of chopped fibers, which increases production speed. In addition, because the volume factor of the forming volume charge is substantially lower than the volume factor of the pieces of chopped fibers, the socket used in the female compression molding die does not need to create a large enough volume to accommodate the stacked chopped fiber pieces. This reduces the size of the die used for compression molding, which reduces the thermal mass of the die. Therefore, this feature results in the technical benefits of reduced heating requirements and faster cycle times.

[0041] The two-step short fiber compression molding process can also provide quality benefits over the conventional one-step short fiber compression molding process. The fiber distribution in the pre-consolidated charge according to this new technology can be more consistent due to its simple geometry and the relatively little flow that occurs during its manufacture, while loose chopped fiber fragments can fall into the cavity of the female die and assume different orientations. More consistent input in a process generally results in more consistent output, thereby reducing variability between different part instances made with the same process and resulting in higher quality.

[0042] Unlike injection molding, which is a single-step process, the compression molding technique described herein is a two-step process in which filling and pressing are performed separately. Using compression molding instead of injection molding provides technical benefits in the form of reduced pressure requirements, reduced processing complexity, and enhanced structural properties because it can accommodate larger reinforcement elements (i.e., short fibers).

[0043] Example

[0044] In the following embodiments, additional processes, systems, and methods are described in the context of compression molding systems for chopped fiber composite parts.

[0045] Fig.101 is a block diagram of a composite manufacturing system 1000 in an illustrative embodiment. The composite manufacturing system 1000 includes a mold 1010 from which a pre-consolidated charge of chopped fibers is manufactured. The composite manufacturing system 1000 also includes a forming volume charge 1020 made of a thermoplastic 1024 and randomly oriented discontinuous fibers 1022 that reinforce the thermoplastic 1024. The forming volume charge 1020 is placed flush against a socket 1032 of a female die 1030, and the forming volume charge 1020 is compression molded into a composite part by driving a protrusion 1042 (e.g., a protrusion for applying a compression molding force) of a male die 1040 into the socket 1032. Heating during compression molding is achieved via a heater 1036 and a heater 1046 that are integral to the die. The heater can include a resistive heating element, a ferromagnetic susceptor heated by induction, a smart susceptor heated by induction, or other heating technology. After the desired shape has been formed, the die is cooled by pumping a cooling fluid (eg, air, water) through the cooling paths 1044 and 1034 of the die.

[0046] With reference to the accompanying drawings in more detail, embodiments of the present disclosure may be Fig.11 The method 1100 shown and Fig.12 1102 is depicted in the context of aircraft manufacturing and service. During pre-production, method 1100 may include specification and design 1104 of aircraft 1102 and material procurement 1106. During production, component and subassembly manufacturing 1108 and system integration 1110 of aircraft 1102 takes place. Thereafter, aircraft 1102 may undergo certification and delivery 1112 for entry into service 1114. While in service by a customer, aircraft 1102 is scheduled for a routine of maintenance and service 1116 (which may also include modification, rebuilding, refurbishment, etc.). Apparatus and methods embodied herein may be employed during any one or more suitable stages of production and service described in method 1100 (e.g., specification and design 1104, material procurement 1106, component and subassembly manufacturing 1108, system integration 1110, certification and delivery 1112, service 1114, maintenance and repair 1116) and / or any suitable component of aircraft 1102 (e.g., airframe 1118, systems 1120, interior 1122, propulsion system 1124, electrical system 1126, hydraulic system 1128, environmental system 1130).

[0047] Each process of method 1100 may be performed or executed by a system integrator, a third party, and / or an operator (e.g., a customer). For the purposes of this specification, a system integrator may include, but is not limited to, any number of aircraft manufacturers and main system subcontractors; a third party may include, but is not limited to, any number of suppliers, subcontractors, and vendors; and an operator may be an airline, a leasing company, a military entity, a maintenance organization, etc.

[0048] like Fig.12 As shown, an aircraft 1102 produced by method 1100 may include a fuselage 1118 having a plurality of systems 1120 and an interior 1122. Embodiments of system 1120 include one or more of a propulsion system 1124, an electrical system 1126, a hydraulic system 1128, and an environmental system 1130. Any number of other systems may be included. Although an aerospace embodiment is shown, the principles of the present invention may be applied to other industries, such as the automotive industry.

[0049] As described above, the apparatus and methods embodied herein may be employed during any one or more stages of production and service described in method 1100. For example, the components or subassemblies corresponding to component and subassembly manufacturing 1108 may be manufactured or processed in a manner similar to the components or subassemblies produced while the aircraft 1102 is in service. Moreover, during subassembly manufacturing 1108 and system integration 1110, one or more apparatus embodiments, method embodiments, or a combination thereof may be utilized, for example, by substantially speeding up assembly of the aircraft 1102 or reducing its cost. Similarly, one or more apparatus embodiments, method embodiments, or a combination thereof may be utilized while the aircraft 1102 is in service, for example and without limitation, during maintenance and repair 1116. For example, the techniques and systems described herein may be used for material procurement 1106, component and subassembly manufacturing 1108, system integration 1110, service 1114, and / or maintenance and repair 1116, and / or may be used for airframe 1118 and / or interior 1122. These techniques and systems may even be used in systems 1120 , including, for example, propulsion system 1124 , electrical system 1126 , hydraulic system 1128 , and / or environmental system 1130 .

[0050] In one embodiment, the component comprises a portion of an airframe 1118 and is manufactured during component and subassembly manufacturing 1108. The component may then be assembled into an aircraft in system integration 1110 and then used in service 1114 until wear renders the component unusable. The component may then be discarded and replaced with a newly manufactured component in maintenance and repair 1116. The inventive components and methods may be used throughout component and subassembly manufacturing 1108 to manufacture new components.

[0051] Any of the various control elements (e.g., electrical or electronic components) shown in the drawings or described herein may be implemented as hardware, a processor implementing software, a processor implementing firmware, or some combination of these. For example, an element may be implemented as dedicated hardware. A dedicated hardware element may be referred to as a "processor," "controller," or some similar terms. When provided by a processor, the function may be provided by a single dedicated processor, a single shared processor, or multiple separate processors, some of which may be shared. In addition, the explicit use of the term "processor" or "controller" should not be interpreted as exclusively referring to hardware capable of executing software, and may implicitly include, but is not limited to, digital signal processor (DSP) hardware, network processor, application specific integrated circuit (ASIC) or other circuit system, field programmable gate array (FPGA), read-only memory (ROM), random access memory (RAM), non-volatile storage device, logic, or some other physical hardware components or modules for storing software.

[0052] In addition, the control element can be implemented as instructions executable by a processor or computer to perform the function of the element. Some embodiments of the instructions are software, program code, and firmware. When executed by a processor, the instructions are operable to direct the processor to perform the function of the element. The instructions can be stored on a storage device readable by the processor. Some embodiments of the storage device are digital or solid-state memory, magnetic storage media such as disks and tapes, hard drives, or optically readable digital data storage media.

[0053] Furthermore, the present disclosure includes embodiments according to the following clauses:

[0054] Item 1. A method for manufacturing a composite component, the method comprising: reducing the volume factor of fragments of chopped fibers when forming the fragments into a pre-consolidated charge; forming a portion of the pre-consolidated charge into a formed volume charge that fits within a die; and compression molding the formed volume charge within the die.

[0055] Clause 2. The method of clause 1, wherein: the preconsolidated charge has a volume factor between 1 and 2.

[0056] Clause 3. The method of clause 1 or 2, wherein: reducing the bulk factor comprises placing pieces of chopped fibers into a mold.

[0057] Clause 4. The method of clause 3, wherein: reducing the volume factor further comprises applying heat and pressure that plastically deforms the fragments into a pre-consolidated charge that conforms to the mold.

[0058] Clause 5. The method of clause 4, wherein: reducing the volume factor further comprises removing the pre-consolidated charge from the mold.

[0059] Clause 6. The method of any of clauses 1 to 5, wherein: compression molding includes positioning a forming volume charge at a socket of the die.

[0060] Clause 7. The method of Clause 6, wherein: positioning the shaped volume charge at the socket comprises placing the shaped volume charge flush against a wall of the socket.

[0061] Clause 8. The method of clause 6 or 7, wherein: compression molding further comprises melting the forming volume charge into molten chopped fibers comprising discontinuous fibers and thermoplastic.

[0062] Clause 9. The method of clause 8, wherein: the forming volume charges have the same mass as the composite part they will be compression molded to form.

[0063] Clause 10. The method of clause 8 or 9, wherein: compression molding further comprises compression molding the molten chopped fibers into a shape defined by the socket, and cooling the molten chopped fibers into the composite part.

[0064] Clause 11. The method of any of Clauses 1 to 10, wherein reducing the volume factor comprises applying a pressure that reduces the volume factor of the chopped fiber pieces from greater than 5 to less than 2.

[0065] Clause 12. The method of any of Clauses 1 to 11, wherein the fragments of chopped fibers comprise portions of chopped composite components.

[0066] Clause 13. The method of any one of clauses 1 to 12, wherein: pieces of chopped fibers are cut from pre-impregnated unidirectional tapes.

[0067] Clause 14. The method of any of Clauses 1 to 13, wherein: reducing the bulk factor comprises applying a pressure between 20 pounds per square inch and 5000 pounds per square inch to the chopped fiber pieces.

[0068] Clause 15. A part of an aircraft assembled according to the method of any one of clauses 1 to 14.

[0069] Clause 16. A non-transitory computer-readable medium comprising programming instructions, the programming instructions being operable, when executed by a processor, to perform the method of any of clauses 1 to 14.

[0070] Item 17. A non-transitory computer-readable medium containing programming instructions that, when executed by a processor, are operable to perform a method for manufacturing a composite component, the method comprising: reducing a volume factor of chopped fiber fragments when forming the fragments into a pre-consolidated charge; forming a portion of the pre-consolidated charge into a formed volume charge that fits within a die; and compression molding the formed volume charge within the die.

[0071] Clause 18. The medium of Clause 17, wherein: the preconsolidated charge has a volume factor between 1 and 2.

[0072] Clause 19. The medium of clause 17 or 18, wherein: reducing the volume factor comprises placing pieces of chopped fibers into a mold.

[0073] Clause 20. The medium of Clause 19, wherein: reducing the volume factor further comprises applying heat and pressure that plastically deforms the fragments into a pre-consolidated charge that conforms to the mold.

[0074] Clause 21. The medium of Clause 20, wherein: reducing the volume factor further comprises removing the pre-consolidated charge from the mold.

[0075] Clause 22. The medium of any one of clauses 17 to 21, wherein: compression molding includes positioning a forming volume charge at a socket of a die.

[0076] Clause 23. The medium of Clause 22, wherein: positioning the shaped volume charge at the socket includes placing the shaped volume charge flush against a wall of the socket.

[0077] Clause 24. The medium of Clause 23, wherein: compression molding further comprises melting the forming volume charge into molten chopped fibers comprising discontinuous fibers and thermoplastic.

[0078] Clause 25. The medium of Clause 24, wherein: the formed volume charges have the same mass as the composite part they will be compression molded to form.

[0079] Clause 26. The medium of clause 24 or 25, wherein: compression molding further comprises compression molding the molten chopped fibers into a shape defined by the socket, and cooling the molten chopped fibers into the composite part.

[0080] Clause 27. The media of any of Clauses 17 to 26, wherein reducing the volume factor comprises applying a pressure that reduces the volume factor of the chopped fiber fragments from greater than 5 to less than 2.

[0081] Clause 28. The media of any of Clauses 17 to 27, wherein the fragments of chopped fibers comprise portions of chopped composite components.

[0082] Clause 29. The media of any of Clauses 17 to 28, wherein: the pieces of chopped fibers are cut from pre-impregnated unidirectional tapes.

[0083] Clause 30. The method of any of Clauses 17 to 29, wherein reducing the bulk factor comprises applying a pressure between 20 pounds per square inch and 5000 pounds per square inch to the chopped fiber pieces.

[0084] Clause 31. A portion of an aircraft assembled according to a method defined by instructions stored on a computer readable medium of any of clauses 17 to 30.

[0085] Clause 32. A system for manufacturing a composite part, the system comprising: a mold that preconsolidates pieces of chopped fibers including discontinuous fibers and a thermoplastic into a preconsolidated charge having a volume factor between 1 and 2; a female compression molding die having a socket defining a shape of the composite part; a male compression molding die having protrusions complementary to the socket; and a shaped volume charge of preconsolidated chopped fibers manufactured from the preconsolidated charge, the shaped volume charge disposed within the socket and flush against at least one wall of the socket.

[0086] Clause 33. The system of clause 32, wherein: the formed volume charge has a volume factor less than 2.

[0087] Clause 34. The system of clause 32 or 33, wherein: the female compression molding die includes an integral heater.

[0088] Clause 35. The system of any of Clauses 32 to 34, wherein the mold includes a recess to receive the fragment.

[0089] Clause 36. The system of any of clauses 32 to 35, wherein: the female compression molding die includes a plurality of sockets and the male compression molding die includes a plurality of protrusions, each protrusion being complementary to a different socket.

[0090] Clause 37. The method of any of clauses 32 to 36, wherein: the preconsolidated charge has a volume factor between 1 and 2.

[0091] Clause 38. The method of any of Clauses 32 to 37, wherein: the forming volume charge has the same mass as the composite part it will be compression molded to form.

[0092] Clause 39. The method of any of Clauses 32 to 38, wherein the fragments of chopped fibers comprise portions of chopped composite components.

[0093] Clause 40. The method of any one of Clauses 32 to 39, wherein: the pieces of chopped fibers are cut from pre-impregnated unidirectional tapes.

[0094] Clause 41. The method of any of Clauses 32 to 38, wherein the fragments of chopped fibers comprise portions of at least one of a chopped composite component and a pre-impregnated unidirectional tape.

[0095] Clause 42. Manufacturing a part of an aircraft using the system of any one of clauses 32 to 41.

[0096] Clause 43. An apparatus for facilitating the manufacture of a composite part, the apparatus comprising: a mold comprising: a plurality of walls; and a recess surrounded by the walls, the recess receiving a fragment of chopped fibers comprising discontinuous fibers and a thermoplastic; and a press sized to complement the mold.

[0097] Clause 44. The apparatus of clause 43, wherein: the die pre-consolidates the pieces of chopped fibers into a pre-consolidated charge having a volume factor between 1 and 2 in response to heat and pressure.

[0098] Clause 45. An article comprising: a bulk formed charge comprising: discontinuous fibers melted from fragments of chopped fibers and a thermoplastic formed to sit flush against the walls of a socket of a compression molding die.

[0099] Item 46. The article of Item 45, wherein: the volume factor of the bulk formed charge is between 1 and 2.

[0100] Although specific embodiments are described herein, the scope of the present disclosure is not limited to those specific embodiments.The scope of the present disclosure is defined by the appended claims and any equivalents thereof.

Claims

1. A method (200, 250) for manufacturing a composite component, the method (200, 250) comprising: When forming the chopped fiber chips (130) into a pre-consolidated charge (400), reducing the volume factor of the chips (130) by applying heat to melt the thermoplastic in the chopped fiber chips (130) and by applying pressure to eliminate air gaps between the chips; forming (204, 257) a portion (500) of the pre-consolidated charge (400) into a formed volume charge (600, 1020) that fits within a die (700, 1030), wherein the forming comprises punching or cutting a plurality of formed volume charges from the pre-consolidated charge (400), each of the formed volume charges having the same mass as a final composite part to be compression molded to form the formed volume charge, and each of the formed volume charges being disposed within a socket (702, 1032) of the die (700, 1030) and flush against at least one wall (706) of the socket to increase conductive heating of the formed volume charge during compression molding; as well as The forming volume charge (600, 1020) is compression molded (206, 262) within the die (700, 1030), wherein the forming volume charge (600, 1020) is melted (260) into molten chopped fibers via application of heat, the forming volume charge (600, 1020) containing no air voids such that the amount of time to melt is reduced.

2. The method (200) of claim 1, wherein: The volume factor of the fragments (130) is reduced so that the pre-consolidation charge (400) has a volume factor between 1 and 2.

3. The method (200, 250) of claim 1, wherein: Reducing the volume factor includes placing (252) the fragments (130) of the chopped fibers into a mold (120, 1010); and The heat and pressure plastically deform the fragments (130) into the pre-consolidated charge (400) that conforms to the mold (120, 1010).

4. The method (200, 250) of claim 1, wherein: Compression molding (206, 262) includes positioning (258) the forming volume charge (600, 1020) at a socket (702, 1032) of the die (700, 1030).

5. The method (200, 250) of claim 4, wherein: The molten chopped fibers include discontinuous fibers (1022) and thermoplastic (1024).

6. The method (200, 250) of claim 5, wherein: Compression molding (206, 262) also includes compression molding (262) the molten chopped fibers into a shape defined by the socket (702, 1032) and cooling (264) the molten chopped fibers into a composite part.

7. The method (200, 250) according to any one of claims 1 to 6, wherein: Reducing the volume factor includes applying a pressure between 20 pounds per square inch and 5000 pounds per square inch to the fragments (130) of chopped fibers.

8. A system (1000) for manufacturing a composite component, the system (1000) comprising: A die (120, 1010) for preconsolidating chopped fiber fragments (130) comprising discontinuous fibers (1022) and thermoplastic (1024) into a preconsolidated charge (400) having a volume factor between 1 and 2, wherein the thermoplastic in the chopped fiber fragments (130) is melted by applying heat and air gaps between the fragments are eliminated by applying pressure, a female compression molding die (700, 1030) having a socket (702, 1032) defining the shape of the composite component; a male compression molding die (900, 1040) having a protrusion (910, 1042) complementary to the socket (702, 1032); and A forming volume charge (600, 1020) of pre-consolidated chopped fibers, the forming volume charge (600, 1020) being manufactured by punching or cutting a plurality of forming volume charges from the pre-consolidated charge (400), each of the forming volume charges having the same mass as a final composite component to be compression molded to form the forming volume charge, and each of the forming volume charges (600, 1020) being disposed within the socket (702, 1032) and flush against at least one wall (706) of the socket (702, 1032) to increase conductive heating of the forming volume charge during compression molding, wherein during compression molding, the forming volume charge (600, 1020) is melted (260) into molten chopped fibers by applying heat, wherein the forming volume charge (600, 1020) does not contain air gaps so that the amount of time required to melt is reduced.

9. The system (1000) of claim 8, wherein: The formed volume charge (600, 1020) has a volume factor less than two.

10. The system (1000) of claim 8, wherein: The female compression molding die (700, 1030) includes an integral heater (930, 1036).

11. The system (1000) of claim 8, wherein: The mold (120, 1010) includes a recess (124) for receiving the fragment (130).

12. The system (1000) according to any one of claims 8 to 11, wherein: The female compression molding die (700, 1030) includes a plurality of sockets (702, 1032), and The male compression molding die (900, 1040) includes a plurality of protrusions (910, 1042), each protrusion being complementary to a different socket (702, 1032).

Images