SPIRALLY INTERTWINED FIBER COMPOSITES

Abstract

An injection-moldable composite pellet comprises a matrix containing a polymer material and at least one fiber embedded in the matrix. The at least one fiber has a first spiral shape and a different composition than that of the matrix. The first spiral shape comprises at least one loop that extends spirally around an axis.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 423,245, filed November 7, 2022, the contents of which are incorporated by reference in their entirety. BACKGROUND

[0002] A composite material is a material composed of at least two constituents to produce a material with improved physical and / or chemical properties. Composite materials are used in various applications that require lightweight and high-strength materials. In the automotive industry, for example, composite materials are used to manufacture oil pans, valve covers, intake manifolds, and various other components or parts. These parts can be manufactured using injection molding by melting a pelletized material or other suitable composite feedstock and injecting the molten composite into a mold to achieve a desired shape that encompasses the composite. SUMMARY

[0003] One aspect of the present disclosure relates to an injection-moldable composite pellet. The composite pellet comprises a matrix containing a polymer material and at least one fiber embedded in the matrix. The at least one fiber has a first spiral shape and a different composition than that of the matrix. The first spiral shape comprises at least one loop that extends spirally around an axis.

[0004] The first spiral shape may have a first length that extends linearly between a first end and a second end of the fiber along the axis, and the composite pellet may have a second length that is greater than the first length. The composite pellet may include a plurality of fibers embedded in the matrix, wherein the fibers may be evenly distributed throughout the matrix. The first spiral shape may have a first length that extends linearly between a first end and a second end of the fiber along the axis, and the composite pellet may have a second length that is equal to the first length. The composite pellet may include a single fiber embedded in the matrix. The at least one fiber may include a recycled material. The at least one fiber may include glass fibers, carbon fibers, or aramid fibers.The matrix may comprise a thermoplastic polymer material or a thermosetting polymer material. The matrix may have a second spiral shape corresponding to the first spiral shape and formed as a coating encapsulating the at least one fiber. The polymer material may be a first material having a first melting point, and the at least one fiber may comprise a second material having a second melting point higher than the first melting point. The polymer material may be a first material having a first tensile strength, and the at least one fiber may comprise a second material having a second tensile strength greater than the first tensile strength.

[0005] One aspect of the present disclosure relates to a composite material. The composite material comprises a matrix comprising a polymer material and a plurality of fibers embedded in the matrix. The fibers each have a spiral shape and are intertwined to form a network within the matrix. The spiral shape comprises at least one loop that extends spirally around a first axis. The fibers are made of a different material than the polymer material.

[0006] The spiral shape may have a diameter that extends linearly along a second axis perpendicular to the first axis and a length that extends linearly between a first end and a second end of the fiber along the first axis. The length may be greater than the diameter. The length is less than or equal to 10 mm. The fibers may comprise a first fiber having a first loop and a second fiber having a second loop, wherein the first loop may be intertwined with the second loop, thereby entangling the first fiber and the second fiber. The polymeric material may be a first material having a first tensile strength, and the at least one fiber may comprise a second material having a second tensile strength greater than the first tensile strength.The polymer material may be a first material having a first melting point, and the at least one fiber may include a second material having a second melting point higher than the first melting point.

[0007] One aspect of the present disclosure relates to a method for forming a plurality of composite pellets. The method comprises melting a fibrous material. The method comprises extruding the molten fibrous material to form continuous fibers each having a spiral shape. The method comprises shortening the continuous fibers to form a plurality of spiral fibers. The method comprises mixing the spiral fibers with a matrix material to form a mixture, wherein the matrix material and the spiral fibers differ in composition. The method comprises melting the mixture, thereby causing the matrix material to encapsulate the spiral fibers. The method comprises extruding the mixture to form an extrudate.The process comprises shortening the extrudate to form the composite pellets, each comprising at least one of the spiral fibers embedded in the matrix material.

[0008] A method for manufacturing a composite part may comprise preparing the composite pellets as described above. The method may comprise melting the composite pellets. The method may comprise injection molding the melted composite pellets to form the composite part, wherein the spiral fibers intertwine within the matrix material. BRIEF DESCRIPTION OF THE CHARACTERS

[0009] The foregoing and other features of the present disclosure will become more apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings. Recognizing that these drawings illustrate only some embodiments according to the disclosure and are therefore not to be considered limiting of its scope, the disclosure is described with additional specificity and detail through the use of the accompanying drawings. Fig. 1 is an image showing the interweaving of a plurality of loosely packed springs, each having a spiral shape, according to one embodiment. Fig. 2 is a schematic perspective view of an example of the structure of a spiral fiber according to an embodiment. Fig. 3, Fig. 4 and Fig. 5 are each a schematic perspective view of an example of the structure of a composite pellet according to various embodiments. Fig. Figure 6 is a flow diagram of an example process for producing spiral fibers as described in Fig. 2, according to one embodiment. Fig. 7 is an image of an example material formed into a spiral shape according to one embodiment. Fig. Figure 8 is a flow diagram of an exemplary process for producing composite pellets as described in the Fig. 3, Fig. 4 or Fig. 5, according to one embodiment. Fig. 9 is a flow diagram of an example process for making a composite part from the composite pellets produced by the example process of Fig. 8, according to one embodiment.

[0010] In the following detailed description, reference is made to the accompanying drawings. In the drawings, like symbols generally refer to like components unless the context dictates otherwise. The example implementations described in the detailed description, drawings, and claims are not to be considered limiting. Other implementations may be utilized and other changes may be made without departing from the spirit or scope of the subject matter presented herein. It is to be understood that the aspects of the present disclosure, as generally described herein and illustrated in the figures, may be arranged, substituted, combined, and configured in a variety of different configurations, all of which are expressly contemplated and made a part of this disclosure. DETAILED DESCRIPTION

[0011] The embodiments described herein generally relate to a composite material and a manufacturing method for a composite material. In particular, the embodiments described herein relate to a pelletized composite material as a starting material for producing a composite material by an injection molding process. The various concepts presented above and explained in more detail below can be implemented in numerous ways, as the described concepts are not limited to any particular implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes.

[0012] In one aspect, embodiments of the present disclosure provide an injection-moldable composite pellet. The composite pellet includes a matrix comprising a polymeric material and at least one fiber embedded in the matrix. The at least one fiber has a first spiral shape and a composition different from that of the matrix. The first spiral shape includes at least one loop spiraling around an axis.

[0013] The first spiral shape may have a first length that extends linearly between a first end and a second end of the fiber along the axis, and the composite pellet may have a second length that is greater than the first length. The composite pellet may include a plurality of fibers embedded in the matrix, wherein the fibers may be evenly distributed throughout the matrix. The first spiral shape may have a first length that extends linearly between a first end and a second end of the fiber along the axis, and the composite pellet may have a second length that is equal to the first length. The composite pellet may include a single fiber embedded in the matrix. The at least one fiber may include a recycled material. The at least one fiber may include glass fibers, carbon fibers, or aramid fibers.The matrix may comprise a thermoplastic polymer material or a thermosetting polymer material. The matrix may have a second spiral shape corresponding to the first spiral shape and formed as a coating encapsulating the at least one fiber. The polymer material may be a first material having a first melting point, and the at least one fiber may comprise a second material having a second melting point higher than the first melting point. The polymer material may be a first material having a first tensile strength, and the at least one fiber may comprise a second material having a second tensile strength greater than the first tensile strength.

[0014] In another aspect, embodiments of the present disclosure provide a composite material. The composite material comprises a matrix comprising a polymer material and a plurality of fibers embedded in the matrix. The fibers each have a spiral shape and are intertwined to form a network within the matrix. The spiral shape includes at least one loop that spirals around a first axis. The fibers are made of a different material than the polymer material.

[0015] The spiral shape may have a diameter that extends linearly along a second axis perpendicular to the first axis and a length that extends linearly between a first end and a second end of the fiber along the first axis. The length may be greater than the diameter. The length is less than or equal to 10 mm. The fibers may comprise a first fiber having a first loop and a second fiber having a second loop, wherein the first loop may be intertwined with the second loop, thereby entangling the first fiber and the second fiber. The polymeric material may be a first material having a first tensile strength, and the at least one fiber may comprise a second material having a second tensile strength greater than the first tensile strength.The polymer material may be a first material having a first melting point, and the at least one fiber may include a second material having a second melting point higher than the first melting point.

[0016] In another aspect, embodiments of the present disclosure provide a method for forming a plurality of composite pellets. The method comprises melting a fibrous material. The method comprises extruding the molten fibrous material to form continuous fibers each having a spiral shape. The method comprises foreclosing the continuous fibers to form a plurality of spiral fibers. The method comprises mixing the spiral fibers with a matrix material to form a mixture, wherein the matrix material and the spiral fibers differ in composition. The method comprises melting the mixture, whereby the matrix material encapsulates the spiral fibers. The method comprises extruding the mixture to form an extrudate. The method further comprises foreclosing the extrudate to form the composite pellets.The composite pellets each contain at least one of the spiral fibers embedded in the matrix material.

[0017] A method for manufacturing a composite part may comprise preparing the composite pellets as described above. The method may comprise melting the composite pellets. The method may comprise injection molding the melted composite pellets to form the composite part, wherein the spiral fibers intertwine within the matrix material.

[0018] Embodiments of the present disclosure provide a composite material having increased strength, toughness, and durability compared to existing composite materials without requiring changes to the compositions of the materials used for a matrix and / or the fibers included in the composite. More specifically, embodiments of the present disclosure relate to a composite material including fibers having a curved, coiled, helical, and / or spiral shape. For convenience, the fibers having a curved, coiled, helical, and / or spiral shape may be referred to hereinafter as "coiled fibers," although the present disclosure does not limit the configurations of the fibers as such. The coiled fibers may, for example, be in the form of a coiled chain with a series of continuous loops (or turns).

[0019] When forming a part (e.g., during the injection molding process, etc.) using the pelletized composite feedstock described herein, the matrix material melts, and the spiral fibers may mobilize within the matrix when pulled apart (e.g., due to the natural movement of the fibers relative to each other and / or tension applied during the injection molding and / or forming process, etc.). In various embodiments, the loops of mobilized fibers become entangled (e.g., entangled, braided, interlaced, coupled, engaged, bonded, interlaced, etc.) to form a bundle or network of spiral fibers, making it difficult to separate individual spiral fibers. In other words, the entanglement of the spiral fibers increases the resistance of the spiral fibers to stresses (e.g., tensile loads) imposed on the composite material.An analogy of such a mechanism can be shown in a bundle of loosely packed springs 106 that become entangled when tension is applied to pull the bundle apart, as in . Fig. 1 shown.

[0020] The entanglement or interlacing of the spiral fibers increases the resistance for the spiral fibers to slide against each other and / or through the matrix when forces (e.g., stresses) are applied to form (e.g., injection and casting) the part. For a formed (e.g., injection-molded) part containing a fiber-reinforced composite material, the fibers of the composite must physically break for the formed part to fracture and / or fail. In this regard, increasing the resistance to sliding due to the entanglement of the spiral fibers described here increases the stress (e.g., tensile stress) required to break the spiral fibers in the composite, resulting in a stronger composite (e.g., with increased tensile strength) compared to a composite with unentangled (e.g., separated, parallel, etc.) and / or straight fibers embedded in the matrix.In other words, the strength of the composite can be improved by altering the fiber structure without changing the composition of the fibers and / or the matrix. Accordingly, the mechanical properties of the molded part can be improved without significantly changing the composition of the composite part or its manufacturing process.

[0021] In some embodiments, the present disclosure provides a starting material used in an injection molding process. The starting material comprises a plurality of pellets that can be melted and formed by the injection molding process to form a part or component containing the composite material described herein. In this context, the pellets are also referred to hereinafter as composite pellets. In various embodiments, each pellet contains at least one of the spiral fibers embedded in a matrix material, wherein the fibers and the matrix material differ in composition and mechanical properties.

[0022] As in Fig. 2, pellets (e.g., pellets 200, 300, and 400 described below) of the composite material may include at least one helically shaped fiber 180. For example, the fiber 180 helically wraps around a central axis AA' (e.g., along the Z-axis) for a distance defined as length (or height) H1 and extends linearly from a first end (e.g., a bottom end) 182 to a second end 184 (e.g., a top end) along the central axis AA'. The fiber 180 is also defined by a diameter D1 that extends linearly along a direction (e.g., along the X-axis) perpendicular to the central axis AA'. In some embodiments, the length H1 is greater than the diameter D1, such that the fiber 180 is elongated along the central axis AA'. In some embodiments, fiber 180 occupies a volume similar to that of a cylinder with diameter D1 and length H1.In this context, the diameter D1 and the length H1 can be used independently or together to describe the size of the fiber 180. In some embodiments, both the diameter D1 and the length H1 are in the millimeter or submillimeter range, while their specific values ​​can vary depending on the size of the pellets into which they are incorporated, as described below.

[0023] Furthermore, the fiber 180 includes a plurality of continuous loops (e.g., turns) 186 spaced apart along the central axis AA' by a distance P. A number N of loops 186 can be any positive integer greater than or equal to 1, such as 2, 3, 8, or 11, etc. Accordingly, the pitch P is defined as the ratio between the length H1 and the number N. In some embodiments, increasing the number N of individual fibers 180 increases the likelihood of forming an entangled network of fibers 180 during an injection molding process because each additional loop 186 in a fiber 180 provides an additional point of entanglement with an adjacent fiber 180. However, the number N should not be too large (e.g., for a given length H1) so that the pitch P is below a threshold corresponding to a distance that allows the insertion of a loop 186 from an adjacent fiber 180.In some embodiments, the diameter D also influences the degree of interlacing between a plurality of fibers 180. In some embodiments, for a given length H1 of the fiber 180, the diameter D, the number N, and / or the pitch P are determined empirically. In some embodiments, the loops 186 are not spaced equally, but rather at different intervals, so that the pitch P varies along the central axis AA'. In some embodiments, the fiber 180 comprises a first section with a series of loops 186 connected in series and a second section that is substantially straight, i.e., without any loops 186.

[0024] In some embodiments, each individual pellet provided herein includes the fiber 180 or a plurality thereof positioned or otherwise arranged in a matrix material (e.g., a polymer matrix material) such that when a plurality of such pellets are melted and subjected to an injection molding process, the fibers 180 intertwine, lock, couple, interlock, bond, or intertwine with one another to increase the degree of entanglement between the fibers 180. In at least one embodiment, as in Fig. 3, a composite material pellet 200 may include only a single fiber 180 embedded in a matrix material 204. In some embodiments, the size of the fiber 180 (e.g., the length, diameter, etc.) may correspond to the overall size of the pellet 200. For example, the length H1 of the fiber 180 and a length (or height) H2 of the pellet 200 extending linearly along a central axis BB' (e.g., along the Z-axis) may be approximately equal, and the diameter D1 may be at least about 50% of a diameter D2 of the pellet 200. In some embodiments, the diameter D1 is approximately equal to the diameter D2.

[0025] In some embodiments, the fiber 180 is positioned within the pellet 200 such that the central axis AA' of the fiber 180 and the central axis BB' of the pellet 200 are aligned, as shown in Fig. 3. In some embodiments, the fiber 180 is positioned within the pellet such that the central axis AA' is angled relative to the central axis BB'. In this context, the length H1 of the fiber 180 may be greater than the length H2 of the pellet 200. In some examples, the length H2 of the pellet 200 may be between about 5 mm and about 10 mm, inclusive. Accordingly, the length H1 of the individual fiber 180 within the pellet 200 is at least on the order of submillimeters, but does not exceed about 10 mm.

[0026] In another embodiment, as in Fig. 4, a pellet 300 may include a plurality of fibers 180 embedded in a matrix material 304. The pellet 300 has a diameter D3 and a length (or height) H3 that extends linearly along a central axis CC' (e.g., along the Z-axis). As illustrated, the diameter D3 is greater than the diameter D1, and the length H3 is greater than the length H1. For example, the diameter D1 and the length H1 of the fibers 180 may be less than or equal to approximately one-quarter, one-fifth, one-sixth, one-tenth, or any other desired size of the diameter D3 and the length H3, respectively, depending on application requirements.

[0027] In some embodiments, the fibers 180 are evenly distributed throughout the matrix material 304. In some embodiments, the fibers 180 are oriented in different directions relative to the central axis CC'. In some embodiments, the pellet 300 includes fibers 180 of different sizes (e.g., different heights and different diameters). In some examples, the length H3 of the pellet 300 may range from about 5 mm to about 10 mm, inclusive. Accordingly, the length H1 of each of the plurality of fibers 180 in the pellet 300 is at least on the order of submillimeters, but does not exceed about 10 mm.

[0028] In still other embodiments and as in Fig. 5, a pellet 400 may be formed in a spiral shape that corresponds to, matches, or approximately matches the shape of a single fiber 180 embedded in a matrix material 404. In this regard, the matrix material 404 may be formed as a coating that encapsulates the single fiber 180. In some embodiments, portions of the matrix material 404 fuse to partially or completely fill a gap between two adjacent loops 186. The pellet 400 has a diameter D4 and a length (or height) H4 that extends linearly along a central axis EE' (e.g., along the Z-axis). As shown, the diameter D4 is approximately equal to the diameter D1, and the length H3 is approximately equal to the length H1. In some examples, the length H4 of the pellet 300 may range from about 5 mm up to and including about 10 mm.Accordingly, the length H1 of the single fiber 180 in the pellet 400 is at least in the order of submillimeters, but does not exceed about 10 mm.

[0029] It should be noted that various fiber and / or matrix geometries may be used in the composite. For example, the fibers may be formed in any shape configured to intertwine. In the embodiments of the Fig. 3-5 the diameter and / or pitch of the spiral fibers can be varied depending on application requirements.

[0030] A method 600 for producing spiral fibers for a composite material is described in Fig. 6. It is noted that method 600 is merely an example and is not intended to limit the present disclosure. Accordingly, before, during, and after method 600 in Fig. 6 additional work steps are planned.

[0031] The method 600 includes, in operation 602, providing a fiber material comprising glass fiber, elemental carbon, polymers (e.g., polyamide), other suitable materials, or combinations thereof. The fiber material may be a virgin fiber material or a recycled fiber material. For example, operation 602 may be performed as part of a recycling process for carbon fibers, glass fibers, aramid fibers (e.g., polyamide), or another fiber material. The method 600 includes, in operation 604, heating and / or melting the fiber material.

[0032] The method 600 in operation 606 includes extruding the heated and / or molten fibrous material to produce fibers having a curved, crimped, and / or spiral shape, such as the spiral shape of fiber 180 described herein. For example, at operation 606, the method 600 may include extruding the heated and / or molten fibrous material by forcing the fibrous material through an orifice (e.g., a hole, an orifice, a nozzle, etc.) of an extruder. The orifice may be structured to produce an extrudate containing a plurality of continuous fibers having the spiral shape, wherein the length of the continuous fibers may be determined based on the amount of extruded fibrous material.

[0033] In at least one embodiment, an inner surface of the opening includes a first portion with a rougher geometry or texture to offer greater resistance to extrusion than a second portion connected to and opposite the first portion, thereby creating an asymmetric flow of the continuous fibers through the opening. Such asymmetric flow causes the continuous fibers to spiral about an axis (e.g., the central axis AA' of fiber 180). In one embodiment, the method 600, at operation 606, produces spiral-shaped fibers, such as fiber 180. In this regard, the fibers produced at operation 606 each include one or more continuous loops, such as loops 186, connected in series along the axis. In some embodiments, the method 600, at operation 606, produces fibers of different shapes and sizes (e.g.,Diameter and length or height). In some embodiments, the heating and / or melting in operation 604 and the extrusion in operation 606 are performed in the same facility and simultaneously.

[0034] The method 600 includes, in operation 608, subsequently processing the continuous fibers by cutting or otherwise shortening them to form discontinuous fibers, each having a spiral shape and sizes (e.g., diameter and length) similar to those of the fibers 180 described herein. In some embodiments, the length (or height) of the spiral fibers is no more than 10 mm, which corresponds to the height (or length) of one of the pellets 200, 300, or 400 described herein. In some embodiments, the resulting spiral fibers have a structure analogous to the structures 650 formed by a food extrusion process, as in Fig. 7 shown.

[0035] A method 700 for producing composite pellets, each containing at least one spiral fiber formed by the method 600 described herein, for an injection molding process is described in Fig. 8. It is noted that method 700 is merely an example and is not intended to limit the present disclosure. Accordingly, before, during, and after method 700, Fig. 8 additional work steps are planned.

[0036] The method 700 includes, in operation 702, providing (or forming) a plurality of spiral (e.g., curved, coiled, and / or helical) fibers, such as the fibers 180 described herein. The plurality of spiral fibers may be produced by any suitable method, such as the method described in Fig. 6. The method 700 includes, at operation 704, mixing the spiral fibers with a matrix material (e.g., a nylon material, etc.) to form a blend.

[0037] In some embodiments, the matrix material comprises a first material and the spiral fibers comprise a second material that is different from the first material, i.e., the fibers and the matrix material have different compositions. In one example, the first material may comprise a polymeric (e.g., organic) material and the second material may comprise an inorganic material. In another example, the first material and the second material each comprise a polymeric material. In some embodiments, the second material has higher strength (e.g., tensile strength) than the first material. In some embodiments, the second material has a higher melting point than the first material. In some embodiments, the first material comprises a thermoplastic polymer material, a thermosetting polymer material, or a combination thereof. The first material may, for example, be a polyamide (e.g., nylon).In some embodiments, the second material comprises glass (e.g., glass fibers), elemental carbon (e.g., carbon fibers), polyamide (e.g., aramid fibers), other suitable fiber materials, or combinations thereof.

[0038] The method 700 includes, at operation 706, heating the mixture to melt the matrix material, which subsequently encapsulates or embeds the spiral fibers. In some embodiments, heating the mixture occurs at a temperature that is at least equal to the melting point of the matrix material (i.e., the first material) but lower than the melting point of the spiral fibers (i.e., the second material).

[0039] The method 700 includes, at operation 708, extruding the mixture to form an extrudate in which the fibers are embedded in the matrix material. The method 700 includes, at operation 710, then processing the extrudate by cutting or otherwise shortening it to form a plurality of composite pellets, such as pellets 200, 300, or 400 described herein. In some embodiments, the composite pellets are formed to have a height (or length) in a range from about 5 mm to about 10 mm, inclusive. In some embodiments, after the spiral fibers are shortened in operation 608, they are further shortened in operation 708. The resulting composite pellets each contain at least one spiral fiber embedded in the matrix material. In one example, the composite pellets may each contain at least one spiral glass fiber embedded in a nylon matrix.In another example, the composite pellets may each contain at least one spiral carbon fiber embedded in a thermoset matrix. In another example, the composite pellets may each contain at least one spiral of aramid fibers embedded in a thermoset matrix.

[0040] A method 800 for performing an injection molding process for producing a composite part using a pelletized starting material is described in Fig. 9. It is noted that method 800 is merely an example and is not intended to limit the present disclosure. Accordingly, before, during, and after method 800, Fig. 9 additional operations are planned.

[0041] The method 800 at operation 802 includes providing (or forming) a pelletized feedstock containing a plurality of composite pellets, such as pellets 200, 300, or 400 described herein, wherein the composite pellets each contain at least one spiral (e.g., curved, coiled, and / or helical) fiber, such as fibers 180, embedded in a matrix material, such as matrix material 204, 304, or 404. The spiral fibers and the composite pellets may be produced by any suitable method, such as methods 600 and 700 described herein, respectively.

[0042] The method 800, in operations 804 and 806, generally comprises melting the composite pellets and then injection molding the molten composite pellets to form the composite part of any size and shape according to the application requirements. In some embodiments, the process of injection molding the molten composite pellets causes the spiral fibers in the composite pellets to intertwine (e.g., couple, connect, interlock, braid, link, entangle, interlock, etc.) and form a bundle or network of intertwined (e.g., braided, entangled, coupled, interlock, linked, interlaced, etc.) spiral fibers in the matrix material of the resulting composite part.In some embodiments, loops, such as loops 186 of fiber 180, of a spiral fiber penetrate and intertwine with the loops of adjacent spiral fibers, creating the intertwining between the spiral fibers. In some embodiments, the entangled spiral fibers require greater force to be physically separated and broken than unentangled (e.g., separated, parallel, etc.) and / or straight fibers. Accordingly, the strength (e.g., tensile strength) of the overall composite material, and thus of the resulting composite part, is increased without altering the composition of the components (e.g., the fibers and the matrix material) of the composite material.

[0043] It should be noted that the term "example" as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and / or illustrations of possible embodiments (and that such term is not intended to imply that such embodiments are necessarily exceptional or superior examples).

[0044] As used herein, the terms "about" and "approximately" generally mean plus or minus 5% of the stated value. For example, "about 0.5" would include 0.475 and 0.525, "about 10" would include 9.5 to 10.5, and "about 1000" would include 950 to 1050.

[0045] The term "substantially" and similar expressions, as used herein, have a broad meaning consistent with the common and accepted usage of those skilled in the art to which the subject matter of this disclosure relates. Those skilled in the art who read this disclosure should understand that these terms are intended to facilitate description of certain described and claimed features, without limiting the scope of those features to the precise numerical ranges specified. Accordingly, these terms should be understood to mean that insubstantial or insignificant modifications or changes to the described and claimed subject matter (e.g., within plus or minus five percent of a particular angle or other value) are considered within the scope of the invention as recited in the appended claims.

[0046] The terms "coupled," "connected," and the like, as used herein, mean the direct or indirect connection of two elements to one another. Such a connection may be stationary (e.g., permanent) or movable (e.g., removable or detachable). Such a connection may be achieved by the two members, or the two members and any additional intermediate members, being integrally formed with one another, or by the two members, or the two members and any additional intermediate members, being fastened to one another.

[0047] It is important to note that the construction and arrangement of the various exemplary embodiments are only illustrative. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art who read this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes, and proportions of the various elements, values ​​of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Other substitutions, modifications, changes, and omissions may also be made in the construction, operating conditions, and arrangement of the various exemplary embodiments without departing from the scope of the embodiments described herein.

[0048] Although this specification contains many specific implementation details, these should not be construed as limitations on the scope of any embodiment or what may be claimed, but rather as descriptions of features specific to particular implementations of particular embodiments. Certain features described in this specification in connection with individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in connection with a single implementation may also be implemented in multiple implementations separately or in any suitable subcombination.Furthermore, although features are described above as operating in certain combinations and even originally claimed as such, in some cases one or more features from a claimed combination may be dropped from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] US 63 / 423,245

[0001]

Claims

[1] Injection-moldable composite pellet comprising: a matrix comprising a polymer material; and at least one fiber embedded in the matrix, the at least one fiber having a first spiral shape and a composition different from that of the matrix, the first spiral shape comprising at least one loop spiraling around an axis. [2] The composite pellet of claim 1, wherein the first spiral shape has a first length extending linearly between a first end and a second end of the fiber along the axis, and wherein the composite pellet has a second length greater than the first length. [3] The composite pellet of claim 2, comprising a plurality of said fibers embedded in said matrix, said fibers being uniformly distributed in said matrix. [4] The composite pellet of claim 1, wherein the first spiral shape has a first length extending linearly between a first end and a second end of the fiber along the axis, and wherein the composite pellet has a second length equal to the first length. [5] The composite pellet according to claim 4 comprises a single fiber embedded in the matrix. [6] The composite pellet of claim 1, wherein the at least one fiber comprises a recycled material. [7] The composite pellet according to claim 1, wherein the at least one fiber comprises glass fibers, carbon fibers or aramid fibers. [8] The composite pellet of claim 1, wherein the matrix comprises a thermoplastic polymer material or a thermosetting polymer material. [9] The composite pellet of claim 1, wherein the matrix has a second spiral shape corresponding to the first spiral shape. [10] The composite pellet of claim 9, wherein the matrix is ​​formed as a coating encapsulating the at least one fiber. [11] The composite pellet of claim 1, wherein the polymeric material is a first material having a first melting point and the at least one fiber comprises a second material having a second melting point higher than the first melting point. [12] The composite pellet of claim 1, wherein the polymeric material is a first material having a first tensile strength and the at least one fiber comprises a second material having a second tensile strength greater than the first tensile strength. [13] Composite material comprising: a matrix comprising a polymer material; and a plurality of fibers embedded in the matrix, the fibers each having a spiral shape and being intertwined with one another to form a network within the matrix, the spiral shape comprising at least one loop spiraling around a first axis, and the fibers comprising a material different from the polymeric material. [14] The composite material of claim 13, wherein the spiral shape has a diameter that extends linearly along a second axis perpendicular to the first axis and a length that extends linearly between a first end and a second end of the fiber along the first axis, and wherein the length is greater than the diameter. [15] The composite material of claim 14, wherein the length is less than or equal to 10 mm. [16] The composite material of claim 14, wherein the fibers comprise a first fiber having a first loop and a second fiber having a second loop, and wherein the first loop is intertwined with the second loop, thereby intertwining the first fiber and the second fiber. [17] The composite material of claim 13, wherein the polymeric material is a first material having a first tensile strength and the at least one fiber comprises a second material having a second tensile strength greater than the first tensile strength. [18] The composite material of claim 13, wherein the polymeric material is a first material having a first melting point and the at least one fiber comprises a second material having a second melting point higher than the first melting point. [19] A method for forming a plurality of composite pellets, comprising: Melting a fiber material; Extruding the molten fiber material to form continuous fibers each having a spiral shape; Shortening the continuous fibers to form a multitude of spiral fibers; Mixing the spiral fibers with a matrix material to form a mixture, wherein the matrix material and the spiral fibers differ in composition; Melting the mixture so that the matrix material encapsulates the spiral fibers Extruding the mixture to form an extrudate; and Shortening the extrudate to form the composite pellets, each comprising at least one of the spiral fibers embedded in the matrix material. [20] A method of manufacturing a composite part comprising: Forming the composite pellets according to claim 19; Melting the composite pellets; and Injection molding of the molten composite pellets to form the composite part, whereby the spiral fibers intertwine within the matrix material.

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