Patent Application
20200115847
The disclosure relates to the field of composite materials. More specifically, the disclosure relates to composites having interlaced fibers in a polymer matrix.
Polymer composite materials include a matrix material and one or more reinforcing materials. The reinforcing materials enhance the strength and/or stiffness of the product while the polymer matrix allows the composite to be formed in complex shapes. The earliest composite materials were reinforced with paper or cotton fabric. Later polymer composites were reinforced by chopped or broken reinforcing fibers randomly disturbed within the matrix. The discontinuous nature of the reinforcing fibers prevented them from achieving significant reinforcement because the strength between isolated fibers was limited by the strength of the matrix material itself or by the adhesion between the matrix material and the fibers.
Later polymer composites incorporated woven mats of reinforcing fibers. The woven mats allowed the full strength and stiffness of the fibers to be employed when the composite was loaded in tension, and to a lesser extent when loaded in compression and flexion. Woven mats also allowed the strands of the reinforcing fibers to be oriented in the optimal direction, or a combination of directions, depending on the expected loading of the part. However, composites manufactured from woven mats greatly increased manufacturing cost and complexity because the mats generally need to be pre-cut and laid in the mold by hand.
3D printing is the process of creating a finished part by depositing (adding) layer after layer of material, until the desired part is obtained. The oldest form of 3D printing is stereolithography, where a bath of liquid polymer is selectively polymerized at its surface by UV radiation. The solidified polymer is then submerged into the liquid so that additional layers can be built upon the previous layers.
The next major innovation in 3D printing was the development of filament deposition modeling (FDM). FDM melts a polymeric or metallic filament and deposits the molten material in thin layers. FDM is faster than stereolithography and allows a wider variety of printing materials. However, neither FDM printing or stereolithography is well suited to fabricating structural components. The first 3D printing system suitable for the fabrication of structural components was selective laser sintering. In this system, a thin layer of metal powder is deposited onto the print surface and selectively sintered by a laser. Another layer of powder is applied over the previously sintered layer, and the process is repeated, so that the second layer is sintered to the first. While these sintered metal components fabricated are suitable for structural applications, their relatively high density makes them unsuitable for some application. Various attempts have been made to adapt FDM printing to create structural composites by adding reinforcement fibers into the polymer filament. While this does improve the mechanical properties, the strength of the fabricated components remains insufficient for use in high-performance applications.
Automated tape placement is a highly precise process for creating composites from unidirectional pre-impregnated textiles (prepreg) textiles. It can be thought of as a more advanced version of the hand lay-up FRP processes, where the human operator is replaced by a robot. This permits very precise fiber placement, but it can only be used on relatively simple curvilinear surfaces. Composites fabricated by automated tape placement are cured by the same methods as hand lay-up.
A method is described for producing an interlaced composite. The method includes: depositing onto a deposition surface a first one or more warp filaments in a first linear direction, inserting, on top of the first one or more warp filaments, a first one or more weft filaments in a second linear direction, where the second direction is in the same plane as the first one or more warp filaments but is not parallel to the direction of the first one or more warp filaments, depositing, on top of the one or more first weft filaments, one or more second warp filaments in first linear direction, where the second one or more warp filaments are not collinear with the first one of more warp filaments, and inserting, on top of the second one or more warp filaments, a second one or more weft filaments in the second direction.
A machine for fabricating three-dimensional interlaced composite components is also disclosed. The machine includes a frame, a print plate supported by the frame, a first plurality of warp heads supported by the frame, which deposit filaments on a print plate and move parallel to each other within a first plane. The machine also includes a second plurality of warp heads supported by the frame which also deposit filaments on the print plate and move parallel to each other within the first plane and which do not move coaxially with any of the first plurality of warp heads. The machine also includes a weft inserter, supported by the frame, which deposits weft filaments on the print plate in a different direction than the first and second plurality of warp heads and traverses the length of the print plate in the same directions as the first and second plurality of warp heads.
A composite component structure is also disclosed which has a plurality of warp filaments interlaced with, and bonded to, a plurality of weft filaments, where the warp filaments are parallel to each other and include one or more reinforcing fibers bonded to a polymer matrix. The weft filaments are parallel to each other and include one or more reinforcing fibers bonded to a polymer matrix. The plurality of weft filaments and the plurality of weft filaments are interlaced in at least two of the following weaving patterns: twill weave, and satin weave. The filaments of the plurality of weft filaments and the filaments of the plurality of weft filaments are continuous where the weaving patterns transition from one pattern to another.
A tape structure is also disclosed which includes transmission material. The transmission material can be made of any material capable of conducting heat or transmitting signals, data, or electric current, including conductive metallic wire and light guide material like optical fiber. The transmission material may be preimpregnated in the filament prior to consolidation or impregnated as part of the consolidation process. An interlaced composite can include multiple transmission material types that perform different functions. An interlaced composite can also include transmission material of the same type in multiple tapes that can interact with each other.
Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the examples, as claimed.
To facilitate an understanding of the principals and features of the disclosed technology, illustrative embodiments are explained below. The components described hereinafter as making up various elements of the disclosed technology are intended to be illustrative and not restrictive. Many suitable components that would perform the same or similar functions as components described herein are intended to be embraced within the scope of the disclosed electronic devices and methods. Such other components not described herein may include, but are not limited to, for example, components developed after development of the disclosed technology.
It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.
By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.
It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a device or system does not preclude the presence of additional components or intervening components between those components expressly identified.
As used herein, “warp” refers to parallel filaments deposited along the primary direction of deposition within a plane.
As used herein, “weft” refers to any filaments deposited along any axis not parallel to the primary direction of deposition within a plane.
As used herein, “plane” refers to the thickness of interlaced composite generated during a single pass of the deposition system.
As used herein, “deposition” refers to adding composite filaments to a composite structure in a controlled fashion and pattern.
As used herein, “consolidation” refers to heating and applying pressure to an assembly of thermoplastic materials in order to form them into a single sheet structure.
As used herein, “composite” refers to a combination of two or more materials differing in form or composition on a macro scale. As used herein, a composite includes, at least, a composite matrix binder and reinforcing elements. The composite constituents do not dissolve or merge completely into one another although they act in concert.
As used herein, “tape” refers to an element having length much greater than its width or thickness.
As used herein, “filament” refers to an element including resin and having length much greater than its width or diameter. In the preferred embodiment, a filament also includes one or more reinforcing fibers.
As used herein, “transmission material” refers to an element that does not include a resin and is capable of conducting heat or transmitting signals, data, or electric current. Examples of transmission material forms as used herein can include a yarn, fiber, wire, sheet, strip, film, or ribbon.
As used herein, “transmission tape” refers to a tape composed partially or entirely of transmission material.
As used herein, “resin” refers to an isotropic material used as a matrix binder within a composite.
As used herein, “thermoset” refers to a polymer which solidifies from a liquid form during processing due to an irreversible chemical reaction.
As used herein, “thermoplastic” refers to a polymer which solidifies from a molten form during processing due to freezing.
As used herein, “engineering polymer” refers to polymers having at least one mechanical, thermal, or electrical material property which is superior to “bulk” polymers such as polyethylene (PE). Examples of engineering polymers include, but are not limited to, nylon (PA), polycarbonate (PC), acetal (PMA), polyetheretherketone (PEEK), poly(p-phenylene sulfide) (PPS), and polyetherketoneketone (PEKK).
As used herein, “sizing” refers to pre-coating a reinforcing fiber with another substance in order to change its properties during processing.
An FRP composite can be made by laminating layers of unidirectional fibers. However, a more balanced composite is created by interlacing non-parallel filaments to create a woven structure. For example, in orthogonal textiles, interlacing the warp and weft yarns generates crimp, or curvature, in the yarns, which affects the overall mechanical properties of the textile. Similar effects are observed in the mechanical properties of composites based on interlaced reinforcing fibers. Woven structures can be classified by fabric geometry into the categories of plain weave, twill weave, and satin weave textiles.
Referring now to the Figures, in which like reference numerals represent like parts, various embodiments of the disclosure will be disclosed in detail.
The deposition process consists, at least, of depositing a continuous filament in a sequence of short segments of two or more groups of warp filaments interspersed with depositing intervening weft filaments. In the preferred embodiment, enough warp filaments are deposited to substantially cover the width of the composite component. The length of the warp segments is determined by the desired pitch of the weft. For clarity and brevity in this section, the warp segments are referred to as “[numeral] segment, [numeral] [type] group. For example, the first segment of the first group of warp filaments is referred to as “first segment, first warp group.”
More complicated weaving patterns may require more than two groups of warp filaments. For a particular weaving pattern, the minimum number of warp groups is equal to the maximum number of warp filaments the weft will pass over plus the maximum number of warp filaments the weft will pass under. For example,
In some embodiments, the deposition sequence can also be tailored to produce different weaving patterns at different locations within the same plane of a single interlaced composite structure. Neither hand-layup FRP nor automated tape-placement machines can achieve this effect.
In some embodiments, multiple layers can be deposited at the same time. In these embodiments, a first two more groups of warp filaments and a weft filament are deposited in the manner described above. However, before advancing to the next weft filament in that layer, a second two or more additional groups of warp are deposited on top of the layer, along with another weft filament, creating two layers of interlaced composite. The number of layers which can be deposited at once is only limited by the sophistication of the deposition machine and the number of warp groups available. In some embodiments, this technique can also interlace warp filaments between layers. Using the two-layer example described above, the warp groups would alternate between which layer was deposited first for each weft location. Thus after the first weft location, at the next weft location the second two or more warp groups and their weft filament deposit first, followed by the first two or more warp groups and their weft filament. In this way, the first two or more warp groups are now in the upper layer and the second two or more warp groups are in the lower layer.
In most embodiments, the warp and weft are orthogonal to each other. However, in some embodiments, favorable material properties may be achieved by creating a smaller angle (less than 90°) between the warp and weft. For example,
In some embodiments, the gaps between filaments may be filled in with additional resin as a post-processing operation. In other embodiments, the filaments may be spaced closely enough together to fuse together during deposition to create a void-free layer. In further embodiments, the filaments may be spaced closely enough together during deposition that a post-processing step can eliminate any gaps. For example, the final part may be removed, heated, and compressed to re-flow the matrix of the filaments, causing it to fill in the gaps and expel any gasses trapped in the gaps.
However, in some embodiments, the gaps may be intentionally left in place to reduce density and crack propagation. For example, in some combinations of resin and fiber, filling the gaps may reduce the strength and/or impact resistance of the final composite part because filling the gaps with resin promotes crack propagation. In some embodiments, the strength and impact resistance of the final part may be especially sensitive to cracks near the interface between the resin and the reinforcing fiber. In these embodiments, leaving the gaps empty may eliminate a pathway for cracks to propagate to this interface, resulting in superior mechanical properties. In other embodiments, leaving the gaps empty may improve the buckling resistance of the filaments and correspondingly improve the overall compressive strength of the part. In these embodiments, the high interfacial strength resulting from allow the gaps to remain allows the fibers to act as reinforced columns of resin where the reinforcing fiber acts as “rebar.”
In the preferred embodiment, the filament includes a high-performance reinforcing yarn coated with a polymer resin to create a composite filament. In some embodiments, the polymer is an engineering polymer. In the preferred embodiment, the resin is polyetherketoneketone (PEKK).
Several important mechanical and processing parameters are relevant to the processing behavior and final mechanical properties of the composite, including melt viscosity, melt temperature, stiffness, toughness, density, and chemical and thermal stability. Because the reinforcing fibers provide the majority of the strength and stiffness in the resulting composite, an appropriate fiber should be selected for the composite filament to achieve optimal performance. In some embodiments, the interface between resin and the reinforcing fiber has the strongest influence on the composite's properties. If the interface is weak, the fiber will pull out of the matrix and fail to carry load, resulting in a lower overall composite strength. Therefore, in some embodiments, surface modification (e.g. etching, sizing) of the fiber may be required for the filament to exhibit good interfacial strength. In some embodiments, nylon 6 or nylon 6.6 may be paired with unsized carbon fiber. In the preferred embodiment, PEKK resin may be paired with unsized carbon fiber.
In some other embodiments, the reinforcing fibers may be aramid (e.g. Nomex®, Kevlar®), metals, glass, silicon carbide, zirconium oxide, or aluminum oxide. Persons skilled in the art will understand that other suitable reinforcing fibers may also be used. In some embodiments, different warp filaments with different reinforcing fibers and/or resins may deposited. In some embodiments, all of the warp filaments in a warp group may be same. In other embodiments, the warp filaments in a warp group may be different.
In some other embodiments, the filament may include a thermoset resin. In these embodiments, the thermoset resin is uncured during deposition. The resin is cured after deposition, resulting in bonding between the warp and weft filaments. In some embodiments, the resin may be selectively cured during each step in the deposition sequence. In some other embodiments, the resin of an entire layer may be cured simultaneously. In some embodiments, the resin may be cured by UV light. In some other embodiments, the resin may be cured by applying heat. In these embodiments, the heat may be applied by conduction, convection, radiation, or any combination of the three.
In some embodiments, the filaments may include comingled thermoplastic resin fibers and reinforcing fibers instead of reinforcing fibers pre-impregnated or pre-coated with resin. In these embodiments, the resin is melted during the deposition process and wets the reinforcing fibers at that time.
In some embodiments, the filament used may be a single-polymer thermoplastic fiber or yarn of multiple thermoplastic fibers. In these embodiments, the resin is not melted during deposition. Instead, the warp and weft are melted and fused where they interlace after deposition. This may occur locally (for example by laser or heated roller) or an entire layer may be fused by passing a heat source over it. This process may desired if a lightweight component is desired with lower stiffness than would be produced by a reinforced composite.
The mechanical system of the composite printer can be considered a combination of a jacquard loom and an FDM printer. Referring now to
In one embodiment, the warp heads 902 are each supported by a guide rod 906 and a lead screw 904. The lead screw 904 also drives the motion of the warp heads 902. The lead screws 904 and guide rods 906 are supported by end plates 908. The end plates 908 and the print plate 916 are supported by a frame 910. Each lead screw 904 is driven by a motor 918. In some embodiments, the lead screws 904 and guide rods 906 may be alternated from the top to bottom position in alternating warp heads 902 to accommodate more tightly packed warp heads 902. In another embodiment, additional mounted plates 908 may be provided farther back from the printing space to accommodate additional motors 918 connected to longer lead screws 904. These embodiments also allow higher warp-head densities. In some embodiments, the lead screw 904 may be connected to the motor 918 through a flexible coupling 912. In some embodiments, the non-driven end of the lead screw 904 may be supported by a floating bearing to prevent binding. In some embodiments, motor and/or lead screw may be fitted with an encoder to indicate the position of the warp head 902 to a control device. In some embodiments, the motors may be stepper motors. In some other embodiments, the motors may be servo motors, direct-current motors, or alternating-current motors, as may be understood by one having ordinary skill in the art.
In some other embodiments, the warp heads 902 may be supported by one or more beams or by multiple guide rods, as may be understood by one having ordinary skill in the art. In further embodiments, the warp heads 902 may be driven by linear motors, chains, belts, pneumatics, or hydraulics, as may be understood by one having ordinary skill in the art.
In one embodiment, the composite filament enters the warp head in the solid state, where it is heated and extruded. The heater section 932 mates to the cover plate 934. The heater section includes a cavity for a heating element 940. In one embodiment, the heating element may be a ceramic cartridge heater. In other embodiments, the heating element may another resistive element, such as nichrome wire, or an inductive coil, as will be understood by one having ordinary skill in the art. The filament to be deposited travels through a channel 942 between the heater section 932 and the cover plate 934. In some embodiment, the warp head 902 may not have a heater section 932. In some of these embodiments, the thermoplastic resin of the filament may be melted remotely as it is deposited, for example by a laser.
The warp filament is preferably supplied from a reel (not shown). The reel is preferably stationary, and mounted remotely from the warp head 902. The filament must be kept under tension to control its placement. In one embodiment, a roller (not shown) on the warp head applies pressure against the print plate 916 to create tension on the filament during deposition. The tension pulls the filament off of a tensioned reel (not shown). This may be described as a “filament pulling” system. In another embodiment, the “filament pushing” system, pair of powered rollers (not shown) pulls the filament off of the reel and forces it into tube (not shown) which guides the filament to the warp head 902. This embodiment is similar to the drive system of a MIG welder for delivering the welding wire to the torch, as will be understood by one having ordinary skill in the art. The overall force on the filament during the extrusion process is a combination of tension on the filament embedded in the molten filament and pressure in the warp head. In another embodiment, tension in the filament can be controlled by varying the torque on the lead screw 904.
The print plate 916, 1270 is also an important component of the printer system. In one embodiment, the print plate 916 moves solely in the vertical (“Z”) axis. As each layer of composite is completed, the print plate 916 drops down so that a new layer can be deposited on top of the previous later.
A more sophisticated print plate 1270 is shown in
In some embodiments, the print plate 1270 also moves in a direction transverse to the motion of the warp heads. This transverse motion allows deposition of warp filaments which is closer together than the center-to-center distance between the warp heads. For example, in one embodiment, after a layer is completed, the print plate 1270 can move transversely by an amount equal to one-half the pitch between the warp heads and repeat the layer. This technique results in a higher warp density than repeating the warp filaments on top of one another, because the second-layer warp filaments will “settle” in the spaces between the first-layer warp filaments.
In some embodiments, the print plate 1270 also rotates about axes orthogonal to the Z axis. In these embodiments, the print plate can tilt, allowing the creation of more complicated three-dimensional composite structures. In the preferred embodiment, the print plate can move linearly in three orthogonal directions and rotate about three axes parallel to those directions.
In some embodiments, the print plate 1270 will be heated during the printing process. This controls the cooling rate of the thermoplastic resins. In one embodiment, the print plate 1270 may be heated by a resistive heating element embedded into the print plate. Unlike the warp heads 1212, 1222, which require an operating temperature above the melt temperature of the thermoplastic matrix, the print plate 1270 operates below the melt temperature and therefore requires less precise temperature control than the warp heads. In other embodiments, the print plate may be heated by a heated fluid, such as water or a water-glycol mixture, or by steam. As will be understood by one skilled in the art, many methods for controlling the temperature of thermoplastic molds may be used to control the temperature of the print plate 1270.
In some embodiments, the print plate 1270 may be treated with a permanent surface treatment, such polytetrafluoroethylene (PTFE), to promote releasing the final composite part. In other embodiments, the print plate 1270 may be treated before each part with a temporary release agent, for example a silicone fluid, as will be understood by one having ordinary skill in the art.
In some embodiments, the printer may include a compression roller 1260. In these embodiments, the compression roller 1260 compresses the interlaced composite structure between deposition of layers. In some embodiments this provides greater consistency in the final composite part. In other embodiments, the compression roller 1260 may be heated. The heating may serve one or more purposes: (1) controlling the cooling of the molten thermoplastic resin in the filaments; (2) melting, or re-melting, the thermoplastic resin to ensure a high-quality bond between the composite filaments (including without limitation warp-to-weft bond and layer-to-layer bond); and (3) curing thermoset resins in composites that employ them.
In one embodiment, the compression roller 1260 has a pair of motive sections 1264 which are driven by at least two lead screws 1266 and two or more guide rods 1268. The lead screws 1266 drive the motive sections 1264 which in turn carry the compression roller 1260 with them. In certain embodiments, the compression roller 1260 may incorporate one or more drive motors 1262. In some embodiments, the drive motor(s) 1262 may provide all of the motive power and the motive sections may run on four guide rods 1268. In other embodiments, the drive motor(s) 1262 work in concert with the lead screws 1266 to move the compression roller 1260s.
The weft inserter must be able to start and end each insertion completely outside of the print space, to allow the warp heads to move between insertions.
In one embodiment, the weft is not melted during insertion, because the molten warp filaments will bond to the weft when they are deposited. In another embodiment, a heating module (not shown) may be added to the end of the rapier to deposit molten weft filament. In another embodiment, the rapier 1242 may be a flexible metal tape driven by a sprocket or drive roller, as will be understood by those skilled in the art.
In this embodiment the entire weft insertion system 1240 travels the length of the print space in the same direction as the warp heads 1204, 1296. This allows insertion of the weft at the proper location. In one embodiment, the weft insertion system 1240 rides on two guide rails 1248 and is driven by a lead screw 1250 and motor 1252. In other embodiments, the weft insertion system may be driven by linear motors, chains, belts, pneumatics, or hydraulics, as may be understood by one having ordinary skill in the art.
As noted above, the deposited warp and weft filaments must be cut once they reach the desired length. Several methods may be used to cut the filaments. In one embodiment, an extendable scissors may be used.
The cutting mechanism includes two cutting blades 1502, two levers 1504; a primary pivot 1506, two secondary pivots 1508, a frame 1510, and a hollow rapier 1512. The levers 1504 are connected to the cutting blades 1502 on one end at the secondary pivots 1508. The other ends of the levers 1504 are free. The cutting blades are rotatably fixed to the frame 1510 at the primary pivot 1506. During cutting operation, a wire or rod (not shown) within the hollow rapier 1512 pulls on the free ends of the levers 1504, drawing them away from primary pivot. The pulling force tends to pull the secondary pivots 1508 and the ends of the cutting blades 1502 toward the hollow rapier 1512. This imparts a moment on the cutting blades 1502 which rotate about the primary pivot 1506, causing a cutting action.
In another embodiment, a rotary cutter may be used to cut the filaments.
In operation, the arm extends into the printing space transversely to the filaments to be cut. For example, to cut warp filaments, the rotary cutter extends into the cutting space in a direction transverse to the motion of the warp heads. The arm provides a down force between the printing plate 916, 1270 and the rotary blade 1602. As the rotary blade 1602 passes over each filament, the filament is severed between the rotary blade 1602 and the printing plate 916, 1270. Although the distance to which the rotary cutter is extends is controlled, it will cut all of the filaments it passes over. Therefore, composite structures with complicated edge geometries must be carefully positioned within the cutting space so that the rotary cutter can cut all of the filaments needed, without cutting unwanted filaments. This limitation means that the rotary cutter is unsuitable for composite structures to be printed with holes in their interiors.
In another embodiment, a drag knife style cutter may be used to cut the filaments.
In operation, the arm extends into the printing space transversely to the filaments to be cut. For example, to cut warp filaments, the drag knife cutter extends into the cutting space in a direction transverse to the motion of the warp heads. The arm provides a down force between the printing plate 916, 1270 and the drag knife 1602. As the drag knife 1602 passes over each filament, the filament is severed between the drag knife 1602 and the printing plate 916, 1270. In one embodiment, the drag knife is fixed to the end of the arm, and has the same limitations as the rotary cutter. In another embodiment, an auxiliary actuator can lift the drag knife slightly from the cutting surface, allowing selective cutting of filaments as the drag knife passes across the print plate.
In some embodiments, one or more tapes may be transmission tapes that include transmission material. Transmission material can include any material suitable for conducting heat or transmitting data, signals, or electric current. Examples of transmission material can include metallic wire, optical fiber and metallic or light guide material. The mechanical and processing parameters of a transmission tape may vary depending on the type of transmission material used and the desired functionality.
For example, in some embodiments, transmission material may be enclosed between two tapes during the consolidation process. As an example,
In some embodiments transmission tape 1800 and 1850 can be manufactured using methods described in paragraphs [0082]-[0086] and FIGS. 7A-9C of International Application No. WO 2017/200935 (incorporated herein in its entirety). For example, transmission wire 1820 or transmission ribbon 1870 could be fed into composite weaving machine 100 in the position one of the middle warp filaments, such as warp filaments 222b-c or 212b-c. The consolidation process described in paragraphs [0082]-[0086] would result in transmission wire 1820 or transmission ribbon 1870 being enclosed between at least one tape above and one tape below.
In some embodiments, the transmission material may be impregnated in a resin prior to consolidation. For example,
In these embodiments, the resin used may depend on the composition and use of the transmission material. As an example, a transmission tape may include transmission material that is metallic wire used for transmitting electric current. Transmitting electric current through metallic transmission material may cause the temperature of the transmission tape to increase. Such a transmission tape would require that the metallic transmission material be impregnated in a resin that can withstand the temperature increase. In one embodiment, the resin may be a thermoplastic polymer with a heat deflection point above the anticipated temperature increase in the transmission tape. In another embodiment, the resin may be a thermoset polymer. A thermoset polymer has the advantage of avoiding the risk of re-melting when heat is applied. In some examples, the resin selected should be compatible with resin used in other filaments in the lattice structure. For example, acrylonitrile butadiene styrene (“ABS”) and polycarbonate are thermoplastic polymers that experience good adhesion. Also, resins in the same polymer family will bond to each other more readily, such as polyamides and polyesters. In contrast, if a nonpolar resin is used with a transmission tape and other filaments in the lattice structure have polar resin, the transmission tape would not bond to the other tapes during consolidation.
In some embodiments, increasing the temperature of the transmission tape may be desirable. For example, transmission tapes integrated into structural components of vehicles or aircrafts can be heated to defrost accumulated ice. Such embodiments may include transmission material made of resistance wire with high resistivity and oxidation resistance. For example, nichrome, an 80/20 alloy of nickel and chromium, is a commonly used resistance material used for heating purposes. Heating transmission tapes may require a resin that can withstand the higher temperatures created by the transmission material, such as a thermoset polymer.
In some embodiments, transmission tapes may absorb heat from a structural body. For example, some embodiments may include tapes with transmission material with high thermal conductivity, such as copper or aluminum. The transmission tape may absorb heat from the structural body, or component fastened to that structural body, such as circuit boards or batteries, in which the interlaced composite is integrated. This can aid in cooling the structural body or component. In examples where the transmission tape is a filament, the resin used must allow heat to pass through to the transmission ribbon. In some examples, it may be preferred that the transmission tape be composed entirely of transmission material to avoid potential obstacles from the conductivity of resin. In such examples, the heat from the structural body or component may then pass directly into the transmission material.
In some embodiments, a transmission tape containing metallic transmission material may need insulation from conductive material that may be used in other tapes. For example, in some embodiments the metallic transmission material may be part of a closed circuit. Carbon fiber is an example of a conductive material that may be used in tapes. If a weave includes a carbon fiber tape in contact with the metallic transmission material, some of the electric current passing through the metallic transmission material may transfer to the carbon fiber tape. Depending on the weave pattern, this can cause the circuit to short. In this example, a non-conductive material is needed between the metallic transmission material and carbon fiber tape to serve as an electrical insulator. For example, in some embodiments the metallic transmission material may be preimpregnated in a non-conductive resin.
In other embodiments, an interlaced composite may include multiple weave layers with at least one non-conductive layer between two conductive layers such that the non-conductive layer electrically insulates the conductive layers from each other. As an example,
In some embodiments, transferring electric current between warp and weft tapes may be desirable. For example, as shown in
Light guide material is another type of transmission material that may be incorporated into weave tapes. Light guide material is a transmission medium that can be used to direct light from one place to another. Some light guide material, such as optical fiber, allow for data transmission using light. Light guide material allows for transmissions over greater distances and at greater speeds than more traditional metallic wires. Additionally, light guide material is unaffected by electromagnetic interference, unlike metallic wires. However, some light guide material can be more delicate and subject to damage under lower stress levels than metallic wire. In such cases, tape fusing methods that apply lighter pressure to the weave may be preferred, such as heat or ultrasonic welding.
In some embodiments, light guide transmission material may be impregnated in a transparent or translucent filament material that allows light diffusion, such as acrylic, polycarbonate, polypropylene, or similar, to create a light guide transmission tape. Light passing through the light guide material may diffuse through the filament material, and the filament may then serve as a light source. For example, a weave containing such light guide transmission tapes may be incorporated into a semi-transparent roof structure, such as the roof of a vehicle. By activating the light source that passes light through the light guide material, the light guide transmission tape may provide cabin lighting.
In some embodiments, multiple warp and weft tapes in an interlaced composite may include metallic transmission material arranged so that the transmission material forms a grid. Such a grid may allow a structural body to detect touch or damage. For example, in one embodiment a grid can create a transparent electrode layer for a capacitive touch panel. In another embodiment, ultrasonic elastic waves may be transmitted as vibrations through the tapes creating a surface acoustic wave (“SAW”) touch panel.
Integrating transmission material into interlaced composites allows data and power to run through structural bodies, which provides for numerous applications in addition to what has already been described herein. For example, an interlaced composite may include metallic transmission material connected to a radio frequency (RF) module. The metallic transmission material may act as an RF antenna for the RF module. Transmission material may be used to detect damage to a structural body as party of a security system or to detect damage before it becomes visible. Transmission material can also be used to detect tampering to a structural body, such as a utility cabinet. Additionally, transmission material can be used to accumulate life cycle data of structural bodies. For example, a vehicle including a processor and memory can store impact or damage information detected by the transmission material. Date and location data could be associated with the impact information to create a record of vehicle damage, in some examples.
Interlaced composites may include multiple transmission ribbons that perform different functions. For example, an interlaced composite may include metallic transmission ribbon acting as an RF antenna, fiber optic material providing lighting, additional fiber optic material providing data transfer, and additional metallic transmission material creating an electric grid to serve as a touchpad. In some embodiments, a single warp or weft tape may include transmission material types that perform different functions. It is contemplated that there may be any number of possible transmission material combinations that are possible insofar as they do not interfere with each other.
Integrating data and power transmission capabilities into interlaced composites as described herein can reduce the volume needed in many structural bodies that house electrical and other wiring. For example, the sizing and shape of many vehicle parts are restricted by the need to run electric components through the vehicle body. Vehicle doors have a minimum thickness required so that they may house wiring required for powering the windows and other functions. Additionally, the touch sensor capabilities of interlaced composites may replace bulkier buttons and knobs, such as for power windows and door locks. By integrating the wiring into the structural body of the door using integrated composites as described herein, the doors to a vehicle may be produced thinner and stronger, thus expanding the cabin space of the car without compromising safety.
The design and functionality described in this application is intended to be exemplary in nature and is not intended to limit the instant disclosure in any way. Those having ordinary skill in the art will appreciate that the teachings of the disclosure may be implemented in a variety of suitable forms, including those forms disclosed herein and additional forms known to those having ordinary skill in the art. For example, one skilled in the art will recognize that executable instructions may be stored on a non-transient, computer-readable storage medium, such that when executed by one or more processors, causes the one or more processors to implement the method described above.
While certain embodiments of this disclosure have been described in connection with what is presently considered to be the most practical and various embodiments, it is to be understood that this disclosure is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
This written description uses examples to disclose certain embodiments of the technology and also to enable any person skilled in the art to practice certain embodiments of this technology, including making and using any apparatuses or systems and performing any incorporated methods. The patentable scope of certain embodiments of the technology is defined in the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
This application is a continuation-in-part of U.S. Application Pub. No. 2018/0038045, filed Oct. 19, 2017 (pending), which is a divisional application of U.S. Pat. No. 9,809,926, filed Aug. 7, 2015, which claims priority to U.S. Provisional Patent Application No. 62/034,930 filed Aug. 8, 2014. This application is also a continuation-in-part of International Application No. PCT/US2017/32703, filed May 15, 2017 (pending), which claims priority to U.S. Provisional Patent Application No. 62/336,974 filed May 16, 2016. The entire contents and substance of each of the above applications is hereby incorporated by reference in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62034930 | Aug 2014 | US | |
| 62336974 | May 2016 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14821502 | Aug 2015 | US |
| Child | 15788061 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15788061 | Oct 2017 | US |
| Child | 16711668 | US | |
| Parent | PCT/US2017/032703 | May 2017 | US |
| Child | 14821502 | US |
