Fiber reinforced tape

Abstract

A fiber reinforced tape can have a thermoplastic resin and a plurality of unidirectional continuous twisted fiber yarns (e.g., carbon fiber yarns) embedded in the thermoplastic resin. Each of the plurality of unidirectional continuous fiber yarns can include 1,000 to 100,000 fibers (e.g., carbon fibers), and each of the fiber yarns can have 4 to 400 twists per meter in a lengthwise direction. The tape can have 0.1 to 2 yarn ends per millimeter in a cross direction. A composite material can be formed from layers of the plurality of fiber reinforced tapes. Advantageously, such tapes and composite materials have high strength and flexibility, and can be used to reinforce high pressure pipes.

Description

[0001] Claim for priority

[0002] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 594,800, filed on October 31, 2023, Attorney Number 1202320, which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure relates to fiber-reinforced tapes comprising unidirectional, continuously twisted fiber yarns (e.g., carbon fiber yarns) embedded in a thermoplastic resin and layered composite materials made from such fiber-reinforced tapes. These fiber-reinforced tapes can be used for the reinforcement and / or repair of high-pressure pipelines. Background Technology

[0004] Fiber-reinforced tapes are used in many applications, including reinforcing pipes. For example, the tape can be wrapped around the inner or outer sections of a pipe to increase or maintain its strength. Conventional tapes use thermosetting resins to help achieve the desired strength. However, thermosetting resins can be difficult to implement with the tape and generally have poor adhesion to layers formed with other materials. Additionally, to increase the strength of the reinforcement, the reinforcing tape is often applied in several layers, which reduces its flexibility.

[0005] Therefore, there is a continued need to develop fiber reinforcements that provide a balance between strength and flexibility. Summary of the Invention

[0006] Advantages of this disclosure include a fiber-reinforced tape with high strength and high flexibility. The fiber-reinforced tape comprises a thermoplastic resin and a plurality of unidirectional continuous fiber yarns embedded in the thermoplastic resin. Advantageously, the plurality of unidirectional continuous fiber yarns can be twisted, for example, having 4 to 400 twists / meter in the length direction.

[0007] In some aspects of this disclosure, the width of the fiber reinforcement strip in the transverse direction can range from 6 mm to 1525 mm. The fiber reinforcement strip may also have 0.1 to 2 yarn ends / mm in the transverse direction. Advantageously, the plurality of unidirectional continuous fiber yarns may consist of carbon fibers (e.g., about 1,000 to about 100,000 carbon fiber filaments).

[0008] In other embodiments, the fiber reinforcement tape may comprise a thermoplastic resin and a plurality of unidirectional continuous fiber yarns embedded in the thermoplastic resin. The plurality of unidirectional continuous fiber yarns include a first twisted fiber yarn and a second twisted fiber yarn, and the first twisted fiber yarn and the second twisted fiber yarn have different twists per meter in the length direction.

[0009] In some aspects, the second twisted fiber yarn comprises at least one of glass fiber yarn, aramid fiber yarn, basalt fiber yarn, ultra-high molecular weight polyethylene fiber yarn, liquid crystal polymer fiber yarn, poly(p-phenylene-2,6-benzodioxazole) fiber yarn, cellulose fiber yarn, rayon yarn, or combinations thereof.

[0010] In another embodiment, the composite material may comprise two or more layers of the fiber-reinforcing tapes of this disclosure. For example, the fiber-reinforcing tape may comprise (a) a thermoplastic resin; and a plurality of unidirectional continuous fiber yarns embedded in the thermoplastic resin, wherein the fiber-reinforcing tape has a transverse width in the range of 6 mm to 1525 mm and has 0.1 to 2 yarn ends / mm in the transverse direction; and each of the plurality of unidirectional continuous fiber yarns comprises 1,000 to 100,000 carbon fibers, and each of the plurality of unidirectional continuous fiber yarns has 4 to 400 twists / m in the length direction, or (b) a thermoplastic resin; and a plurality of unidirectional continuous fiber yarns embedded in the thermoplastic resin, wherein the plurality of unidirectional continuous fiber yarns comprises a first twisted fiber yarn and a second twisted fiber yarn, and the first twisted fiber yarn and the second twisted fiber yarn have different twists per millimeter in the length direction, or a combination of (a) and (b).

[0011] Another embodiment includes a conduit having a reinforcing layer, wherein the reinforcing layer includes at least one fiber reinforcing strip of the present disclosure.

[0012] Other advantages of this disclosure will become apparent to those skilled in the art from the following detailed description, in which only certain embodiments are shown and described, merely to illustrate how certain subjects are carried out. As will be appreciated, the invention is capable of having other and different embodiments, and several details thereof can be modified in various ways without departing from the invention. Therefore, the drawings and description are to be considered illustrative rather than restrictive. Attached Figure Description

[0013] Referring to the accompanying drawings, elements having the same reference numerals represent similar elements in all the drawings, and wherein:

[0014] Figure 1A and Figure 1B This is a schematic diagram of a fiber-reinforced tape according to an embodiment of the present disclosure. Figure 1B It shows Figure 1A A cross-sectional view of the band.

[0015] Figure 2A , Figure 2B and Figure 2C A conventional tape with impregnated fiber filaments is shown. Figure 2AAn image showing a top view of a standard belt is displayed. Figure 2B A cross-sectional image of a conventional strip is shown. Figure 2C A cross-sectional image of a conventional strip is shown schematically.

[0016] Figure 3A , Figure 3B and Figure 3C A fiber-reinforced tape according to one or more embodiments of the present disclosure is shown. Figure 3A An image showing a top view of the belt is displayed. Figure 3B A cross-sectional image of the band is shown. Figure 3C A cross-sectional image of the strip of this disclosure is shown schematically.

[0017] Figure 4 This is a schematic diagram illustrating the possible relative orientations of the fiber yarns in the layers of the fiber-reinforced tape of this disclosure.

[0018] Figure 5 A perspective view of a composite material is shown, which comprises three fiber-reinforced tape layers, wherein the fiber yarns in the tape layers are aligned relative to each other in a 0-0-0 orientation (i.e., all fiber yarns are aligned along the Z-axis).

[0019] Figure 6 A perspective view of a composite material is shown, which comprises three fiber-reinforced tape layers, wherein the fiber yarns in the tape layers are aligned relative to each other in a 0-90-0 orientation (i.e., the alternating tapes are rotated 90° relative to the Z-axis).

[0020] Figure 7 A perspective view of a composite material is shown, which includes two fiber-reinforced tape layers, wherein the fiber yarns in the tape layers are oriented relative to each other at 45°–45° (i.e., the first (top) tape layer is rotated 45° relative to the positive Z-axis, and the second (bottom) tape layer is rotated 45° relative to the negative Z-axis, such that the fiber yarns in one tape layer are oriented perpendicularly to the adjacent tape layer).

[0021] Figure 8 A perspective view of a composite material is shown, which includes three fiber-reinforced tape layers, wherein the fiber yarns in the tape layers are oriented relative to each other at a 0°–45°–45° orientation (i.e., the fiber yarns of the top tape layer are oriented along the Z-axis, and each subsequent tape layer is rotated 45° relative to the positive and negative Z-axis, such that the fiber yarns in the middle layer are oriented perpendicularly to the fiber yarns in the bottom tape layer).

[0022] Figure 9 It is a schematic diagram of a pipe having a reinforcing layer consisting of one or more fiber-reinforced strips of this disclosure.

[0023] Figure 10 The bending test of the composite material according to ASTM D790 is shown. Detailed Implementation

[0024] This disclosure can be better understood by referring to the following description (including the following definitions and examples). Specific features of the disclosed compositions and methods described herein in the context of individual aspects may also be provided in combination in a single aspect. Alternatively, for the sake of brevity, various features of the disclosed compositions and methods described in the context of a single aspect may also be provided individually or in any sub-combination.

[0025] Unless otherwise defined herein, scientific and technical terms relating to this application shall have the meanings commonly understood by one of ordinary skill in the art. Furthermore, unless the context requires otherwise, singular terms shall include plural forms, and plural terms shall include singular forms.

[0026] As stated above and throughout this disclosure, unless otherwise indicated, the following terms and abbreviations shall be understood to have the following meanings.

[0027] The singular forms “a”, “an”, and “the” used in the specification (including the claims) include the plural form, and references to a particular value include at least that particular value, unless the context clearly specifies otherwise.

[0028] This disclosure relates to a fiber-reinforced tape comprising a thermoplastic resin and a plurality of unidirectional, continuously twisted fiber yarns embedded in the thermoplastic resin. As used herein, tape is a continuous strip, and the term may be used interchangeably with belt or ribbon. Figure 1A Fiber-reinforced tapes according to certain aspects of this disclosure are shown. Figure 1B Show Figure 1AA cross-sectional view of the belt. As shown, belt 100 comprises a plurality of fiber yarns 110 embedded in thermoplastic resin 120. Furthermore, each yarn comprises multiple fibers, i.e., filaments (160). The yarns are unidirectional and continuous, and although not shown for convenience, the yarns are twisted. Referring to the Z, X, and Y axes, the belt may have a length in the Z direction, a width (130) in the X direction, and a thickness in the Y direction. The belt length may be greater than or similar to its width, but the belt thickness may be significantly less than its length or width. For example, the width of the fiber reinforcement tape in the transverse direction can range from about 6 mm to about 1525 mm (about 0.25 inches to about 60 inches), such as from 10 mm, 15 mm, 20 mm, 25 mm, 50 mm, 75 mm, 100 mm, 150 mm, 200 mm, 250 mm to about 1525 mm, 1500 mm, 1400 mm, 1300 mm, 1200 mm, 1000 mm, 900 mm, 500 mm, 200 mm, or any value or range therebetween. Furthermore, the thickness (Y direction) of the fiber reinforcement tape can range from about 0.75 mm to about 5 mm (about 0.03 inches to 0.2 inches), such as from about 0.75 mm or 1 mm to about 3 mm, 4 mm, 5 mm, or any value or range therebetween.

[0029] like Figure 1B As further shown, the belt may have a certain number of yarn ends (140) / mm in width or transverse (X direction). The number of yarn ends / mm is an indication of the stacking of yarns in the belt. In some embodiments, the fiber-reinforced belt may have about 0.1 to about 2 yarn ends / mm (2 to 50 yarn ends / inch) in the transverse direction, for example from about 0.2, 0.5, 0.7 to about 2, 1.5, 1 yarn ends / mm in the transverse direction, or any value or range therebetween.

[0030] As used herein, a fiber yarn, also referred to as a tow or roving, is a continuous, untwisted bundle of fibers. A fiber yarn may comprise from about 1,000 to about 100,000 individual fibers, and may also be referred to as a filament. The number of fibers in a yarn may be specified as 3k, 6k, 12k, and 15k, where “k” stands for “thousand,” such that a 3k yarn has 3,000 filaments. In some aspects of this disclosure, a continuous fiber yarn may comprise from about 1,000 fibers to about 100,000 fibers, for example from about 1k, 6k, 12k, 15k, 20k fibers to about 90k, 70k, 50k fibers, or values ​​or ranges therebetween. Individual fibers may be held together and / or protected by organic coating, sizing, or a combination thereof.

[0031] Furthermore, continuous fiber yarns can be twisted together in a helical arrangement using either an S-twist (the yarn appears to be pointing "up" to the left) or a Z-twist (the yarn appears to be pointing "up" to the right). The direction and amount of twist of the yarn affect the final properties of the yarn and tape. By twisting the yarn, the physical cohesion of individual filaments is introduced, which affects ease of handling and some mechanical properties. Although not all fibers behave the same after being twisted, twisting is considered to increase the strength of the fiber yarn (up to a certain level of twist), decrease its modulus, and increase its elongation.

[0032] In some aspects of this disclosure, each of the plurality of unidirectional continuous yarns may have about 4 to about 400 twists / meter (0.1 to 10 twists / inch) in the length direction of the yarn. For example, each of the plurality of unidirectional continuous yarns may have about 4, 8, 12, 16, 20, 24, 28, 32, 36, 40 to about 400, 360, 320, 280, 240, 200 twists / meter, or any value or range therebetween, in the length direction of the yarn.

[0033] Furthermore, the twisted fiber yarns implemented in the tape of this disclosure can have different twists per meter. That is, in some aspects, the plurality of unidirectional continuous fiber yarns embedded in the thermoplastic resin of the tape of this disclosure can have a first twisted fiber yarn having a different twist per meter in the length direction than the second twisted fiber yarn or even the third or fourth twisted fiber yarn.

[0034] In some embodiments of this disclosure, multiple unidirectional continuous fiber yarns are composed of carbon fibers; for example, multiple unidirectional continuous fiber yarns are carbon fiber yarns. Additionally, multiple unidirectional continuous fiber yarns may include more than one type of yarn material. For example, the multiple unidirectional continuous fiber yarns in the tape of this disclosure may include a first twisted fiber yarn, for example, composed of carbon fibers, and a second twisted fiber yarn, composed of fibers of different materials, and even third and fourth twisted fiber yarns, composed of even more different materials. In some aspects, additional twisted fiber yarns (one or more), such as the second twisted fiber yarn, may be glass fiber yarn, aramid fiber yarn, basalt fiber yarn, ultra-high molecular weight polyethylene fiber yarn, liquid crystal polymer fiber yarn, poly(p-phenylene-2,6-benzodioxazole) fiber yarn, cellulose fiber yarn, rayon yarn, or any combination thereof.

[0035] In some embodiments, the breaking elongation of the first twisted fiber yarn can be substantially the same as that of the second twisted fiber yarn, for example, within ±5%. In other aspects, the breaking elongation of the first twisted fiber yarn can be within ±10%, ±15%, or ±20% of the breaking elongation of the second twisted fiber yarn.

[0036] like Figure 1B As further shown, the multiple fiber yarns are not completely impregnated with thermoplastic resin. That is, the fiber yarn (110) has a very small amount of thermoplastic resin (120) between the yarn filaments (160). The use of twisted fiber yarns in the fiber-reinforced belt of this disclosure allows many individual filaments to be in direct contact with each other, while very little resin penetrates into the yarn volume. This unimpregnated yarn structure contrasts with impregnated fiber belts, which have separate individual filaments with resin penetrating into the spaces between the filaments. Furthermore, by embedding multiple continuous twisted fiber yarns with resin instead of impregnating the yarns with resin, the belt has relatively less resin and relatively more yarn by weight, resulting in a high-strength yet flexible belt. In addition, in some respects, the continuous twisted fiber yarns can contact both the upper and lower surfaces of the belt.

[0037] Figure 2A-2C A conventional tape (200) is shown, which has fibers (260) impregnated with resin (220). Figure 2A The image shown is a top view with (200) as the reference. Figure 2B A cross-sectional image of a conventional strip is shown. Figure 2C A schematic cross-sectional image of a conventional tape is shown. As shown, resin (220) in the conventional tape is contained between fiber filaments 260 in the tape. In contrast, the fiber-reinforced tape of this disclosure may have multiple fiber yarns embedded in resin (rather than impregnated with resin). Figures 3A-3C This structure is illustrated. For example... Figures 3A-3C As shown, the fiber-reinforced tape (300) may have multiple fiber yarns (310) embedded in a thermoplastic resin (320) (instead of being impregnated with resin). Figure 3C As shown, the example tape (300) can have very little resin (320) between the filaments (360). This construction uses significantly less resin and allows for a more flexible tape.

[0038] Thermoplastic resins that can be used to prepare the tapes of this disclosure include, for example, polyolefins such as polyethylene, poly(ethylene-vinyl acetate), or combinations thereof. Other resins that can be used to prepare the tapes of this disclosure include, for example, polyesters and their copolymers, polyamides, polyvinyl chloride, polyurethanes, thermoplastic vulcanizates, polyetheretherketones, polyetherimides, polyphenylene sulfides, polyacrylates such as polymethyl methacrylate, or combinations thereof. Advantageously, thermoplastic resins allow the tapes to be reworked by heating for reshaping or bonding. Thermoplastic resins also allow the tapes to be recycled.

[0039] As described above, the fiber-reinforced tape of this disclosure advantageously has a relatively small amount of resin to maintain flexibility. In some aspects, based on the total weight of the fiber-reinforced tape, the fiber-reinforced tape comprises from about 5 wt% to about 80 wt% of thermoplastic resin and from about 20 wt% to about 95 wt% of a plurality of unidirectional continuously twisted fiber yarns. For example, based on the total weight of the fiber-reinforced tape, the fiber-reinforced tape may comprise from about 5 wt% to about 35 wt% of thermoplastic resin and from about 65 wt% to about 95 wt% of a plurality of unidirectional continuously twisted fiber yarns.

[0040] Furthermore, the fiber-reinforced tape of this disclosure can have a higher porosity than conventional fiber-reinforced tapes. For example, the fiber-reinforced tape of this disclosure can have a porosity in the range of about 15% to 50%, such as about 17% to about 47%. The porosity can be determined by computed tomography (CT).

[0041] In some aspects, the fiber-reinforced tape of this disclosure may have a strength of about 100 g / m². 2 Approximately 5000g / m 2 areal weight within a range, for example, from approximately 1000 g / m³. 2 Approximately 2500g / m 2 .

[0042] In other respects, the fiber-reinforced tape of this disclosure may have a tensile elongation in the range of about 2% to about 10%, for example, in the range of about 5% to about 10%.

[0043] The fiber-reinforced tapes of this disclosure can also be used to form composite materials. Such composite materials may comprise layers of two or more fiber-reinforced tapes of this disclosure. Advantageously, the layers of two or more fiber-reinforced tapes may be adhered to each other with a thermoplastic resin to form a composite laminate.

[0044] Furthermore, the fiber yarns in each layer of the composite material may be oriented in the same or different directions relative to each layer. For example, the composite material may include a layer of first fiber-reinforced belt and a layer of second fiber-reinforced belt, wherein in the first fiber-reinforced belt layer, a plurality of unidirectional continuous fiber yarns are oriented in a first direction, and in the second fiber-reinforced belt layer, a plurality of unidirectional continuous fiber yarns are oriented at an angle greater than or equal to 0° and less than or equal to 90° relative to the plurality of unidirectional continuous fiber yarns in the first fiber-reinforced belt layer. The composite material may include additional layers of fiber-reinforced belts of this disclosure, wherein the fiber yarns in the additional layers are oriented at an angle greater than or equal to 0° and less than or equal to 90° relative to the fiber yarns in adjacent layers of the composite material.

[0045] Figure 4-8 Various composite materials and the relative orientation of fiber yarns in the layers forming the composite material belt are shown. For example, Figure 4Various orientations of the fiber yarns in composite materials having two or three fiber-reinforced tape layers are illustrated in this disclosure. These orientations include 0-0-0, 0-90-0, 45-45 (i.e., a positive 45-degree rotation and a negative 45-degree rotation), and 0-45-45. Other relative orientations, including 0-67, are also considered in this disclosure.

[0046] Figure 5 A perspective view of a composite material (500) comprising three fiber-reinforced tape layers (502, 504, 506) is shown, wherein the fiber yarns in the tape layers are aligned relative to each other in a 0-0-0 orientation. As illustrated in the figure, multiple fiber yarns in the first tape (502) are oriented along a first direction (i.e., the Z direction (longitudinal) or 0° relative to the Z-axis). The second tape layer (504) and the third tape layer (508) are combined such that the fiber yarns in each tape layer are oriented along the same Z direction, thereby producing a three-tape composite material in which the fiber yarns in each layer are oriented along the same Z direction.

[0047] Figure 6 A perspective view of a composite material (600) comprising three fiber-reinforced tape layers (602, 604, 606) is shown, wherein the fiber yarns in the tape layers are aligned relative to each other with a 0-90-0 orientation. As illustrated in the figure, a plurality of fiber yarns in the first tape (602) are oriented along a first direction (i.e., the Z-direction (longitudinal)), and the fiber yarns of the second tape layer (604) are oriented at a 90° angle relative to the orientation of the fiber yarns in the first tape (602), that is, the fiber yarns in the second tape are oriented at a 90° angle relative to the Z-axis or at a 0° angle relative to the X-axis. The fiber yarns of the third tape layer (606) are oriented at a 0° angle relative to the orientation of the fiber yarns in the first tape (602).

[0048] Figure 7 A perspective view of a composite material (700) comprising two fiber-reinforced tape layers (702, 704) is shown, wherein the fiber yarns in the tape layers are oriented relative to each other at a 45-45 degree orientation. As illustrated in the figure, a plurality of fiber yarns in the first tape (702) are oriented in a first direction, i.e., the tape and fiber yarns are rotated 45° positive relative to the Z-axis. The fiber yarns of the second layer (704) are rotated 45° negative relative to the Z-axis, such that the fiber yarns in the first tape (702) are oriented perpendicularly (90°) to the fiber yarns in the second tape layer (704).

[0049] Figure 8A perspective view of a composite material (800) comprising three fiber-reinforced tape layers (802, 804, 806) is shown, wherein the fiber yarns in the tape layers are aligned relative to each other at a 0-45-45 degree orientation. As illustrated in the figure, a plurality of fiber yarns in the first tape (802) are oriented along a first direction (i.e., the Z direction (longitudinal) or 0° from the Z-axis). The second tape layer (804) and the third tape layer (806) are rotated 45° positive and 45° negative relative to the Z-axis, respectively, such that the fiber yarns in the second tape layer (804) are oriented perpendicularly to the fiber yarns in the third tape layer (806). Heat can be applied to... Figure 5-8 Each of the composite materials shown is formed as a laminate of the composite material.

[0050] In some aspects, the composite materials or laminates thereof disclosed herein may have a flexural strength in the range of about 1 MPa to about 50 MPa, for example from about 10 MPa to about 20 MPa. In other aspects, the composite materials or laminates thereof disclosed herein may have a flexural modulus in the range of about 0.1 GPa to about 15 GPa, for example from about 1 GPa to about 5 GPa.

[0051] Another aspect of this disclosure includes pipes reinforced with one or more fiber-reinforced tapes or laminated composites of the present disclosure. The tensile fatigue resistance of the tape is a factor to consider in applications such as pipe reinforcement, as circumferential stress (followed by tensile failure) can cause failure in high-pressure piping applications. However, the fiber-reinforced tapes of this disclosure can be embossed or laminated to have sufficient strength to reinforce pipes, such as high-pressure pipes used to transport gases (e.g., natural gas or hydrogen). Furthermore, the fiber-reinforced tapes of this disclosure are flexible enough to allow for on-site installation of the tape to existing pipes, thereby allowing for on-site repair and / or maintenance of existing pipes.

[0052] Figure 9 A reinforced conduit with a reinforced layer consisting of one or more fiber-reinforced strips of the present disclosure is shown. As shown in this example, the conduit 900 comprises three layers: an outer layer or sheath (910), a reinforcing layer (912), and an optional inner liner (914). The outer sheath may be made of metal, such as steel or plastic. The reinforcing layer may consist of at least one fiber-reinforced strip of the present disclosure. Alternatively, the reinforcing layer may consist of layers of several such strips, such as two, three, four, five, six, seven, etc., layers of fiber-reinforced strips of the present disclosure. In one aspect of the present disclosure, the one or more fiber-reinforced strips may be helically wound along the longitudinal direction of the conduit, i.e., along the Z-axis direction, which points outwards from the drawing plane.

[0053] The inner layer may be composed of polyolefins such as polyethylene, polypropylene, polyvinylidene fluoride, polyvinyl chloride, polycarbonate, polyamide, polyurethane, etc., or any combination thereof.

[0054] although Figure 9 A three-layer construction with a reinforcing intermediate layer is shown, but reinforced pipes can have a reinforcing layer on the pipe itself, so that the pipe can be made of metal or plastic and the reinforcing layer can be on the outer surface of the pipe.

[0055] Furthermore, the reinforcing layer may include one or more helically wound fiber reinforcing tapes of this disclosure, wherein the fiber yarns are oriented at an angle of ≥0° and ≤90° relative to the longitudinal direction of the conduit, i.e., along the direction of Figure 9 The direction of the Z-axis outside the plane in the diagram.

[0056] Example

[0057] Fiber-reinforced tapes with untwisted or twisted fiber yarns were tested. The tapes were laminated to form a composite structure, which was then tested.

[0058] Comparative example (impregnated composite material with untwisted yarn)

[0059] Untwisted 24K filament single-ended roving carbon fibers are drawn along the machine direction of the composite tape processing production line. Polymer melt (high-density polyethylene) is fed into the crosshead impregnation die geometry and bonded to the carbon fiber roving, then cooled and wound onto the core material to obtain a polymer-impregnated unidirectional carbon fiber tape. The tensile properties of the tape are tested according to ASTM D3039 (Standard Test Method for Tensile Properties of Polymer-Based Composites), by cutting the tape into 19 mm wide and 1200 mm long pieces and stretching them at a test speed of 10 mm / min in a general-purpose testing machine.

[0060] The flexural properties of the composite material were tested by laminating 6-12 strips in a flatbed press (all layers either along the fiber direction or alternating between layers at 45-90° relative to the fiber direction). These laminates were cut into 12mm wide by 64mm long bars by water jetting according to ASTM D790 (Standard Test Method for Flexural Properties of Unreinforced and Reinforced Plastics and Electrical Insulators), and then bent on a general-purpose testing machine at a test speed of 12mm / min and a span / depth ratio of 16:1.

[0061] Example 1 (Twisted Fiber Reinforced Belt Composite Material)

[0062] Along the machine direction (length direction), 24K single-ended roving carbon fibers are twisted in the S or Z direction on a toroidal twister to approximately 0.02 twists / mm (approximately 20 twists / m). These discrete twisted rovings are pulled along the machine direction of the composite tape processing line. A polymer melt (high-density polyethylene) is fed into the crosshead impregnation die geometry and bonded together with the twisted carbon fiber rovings, then cooled and wound onto a core material to obtain an unimpregnated twisted carbon fiber tape. This process is designed to obtain an unimpregnated tape by not engaging the crosshead impregnation die geometry; that is, the fibers are pulled through open channels in a process similar to pultrusion. This process uses the same equipment and geometry as impregnating fiber yarn tape, except that the impregnation process has an impregnation geometry in a fully engaged die, where the fibers fully interact with the die and generate a driving force that allows the melt to penetrate the fibers.

[0063] The tensile properties of these tapes were determined by pulling them at a test speed of 63.5 mm / min on a general-purpose testing machine, according to ASTM D6775 (Standard Test Method for Breaking Strength and Elongation of Textile Ribbons, Tapes and Braids).

[0064] The flexural properties of the composite were tested by laminating 2-3 strips in a flatbed press (all layers either along the fiber direction or alternating between layers at 45-90° relative to the fiber direction). According to ASTM D790, these laminates were cut into 12mm wide by 64mm long bars by water jetting and bent on a general-purpose testing machine at a test speed of 12mm / min and a span / depth ratio of 16:1.

[0065] The physical properties of untwisted and twisted carbon fiber tape constructions were compared. Layers of untwisted and twisted carbon fiber tapes were loaded into thermoplastic resin to achieve comparable tensile strength. The untwisted fiber yarn tape achieved a fiber loading of approximately 60 wt% fiber and approximately 40 wt% thermoplastic resin, while the twisted carbon fiber tape construction achieved an 80% fiber loading. The higher percentage by weight of carbon fiber yarn resulted in a significantly higher areal density of 1350 g / m³. 2 And thickness (1 mm), as summarized in Table 1. Therefore, fiber-reinforced tapes with twisted yarns have certain advantageous properties involving strength and areal density.

[0066] Table 1. Properties of the fiber-reinforced tapes constituting the laminate.

[0067]

[0068] The mechanical properties of untwisted and twisted fiber tapes were compared using a general testing machine and summarized in Table 2 below.

[0069] Table 2. Mechanical properties of the fiber-reinforced tapes constituting the laminate.

[0070]

[0071] Although the tape is constructed to have a similar tensile strength of approximately 1600 MPa, the twisted carbon fiber yarn tape construction exhibits significantly higher elasticity (10.5% elongation vs. 1.7%) compared to the untwisted carbon fiber yarn tape, and also shows significantly higher maximum load strength (160 kg / mm ​​vs. 25 kg / mm).

[0072] For untwisted carbon fiber yarn tapes, the ASTM D3039 tensile test method is used to measure the force required to break the polymer composite specimen and the extent to which the specimen is stretched or elongated to that point. D3039 is more suitable for rigid thermosetting composites. The breaking strength and elongation of twisted carbon fiber yarn tapes are measured using the ASTM D6775 test method.

[0073] Composite materials

[0074] Laminated composites are prepared by stacking carbon fiber impregnated tapes in an offset orientation, where the orientation, expressed in angle, refers to the longitudinal axis of the carbon fiber yarns in each tape layer (e.g., ...). Figure 5-8 The relative orientation of the carbon fiber ribbons (within the Z-axis) varies. The composite material stacks are prepared as follows: carbon fiber yarns in the layers are stacked in parallel orientation (0-0-0), perpendicular orientation (0-90-0), cross-directional orientation with respect to the longitudinal axis (where the carbon fiber yarns in the ribbon layer are perpendicular to the carbon fiber yarns in the lower layer (45-45)), and cross-directional 45-45 stacks with an additional top layer (the carbon fiber yarns in the ribbon of this additional top layer are oriented at zero degrees relative to the Z-axis). Table 1 shows the orientation of the carbon fiber ribbons with respect to the carbon yarns. As further shown in Table 1, the ribbons constructed from twisted carbon fibers are thicker than unidirectional carbon fiber ribbons. Therefore, to compare the flexural strength of composites with similar thicknesses, a laminate with a unidirectional ribbon structure was prepared with 12 layers, and a laminate with a twisted carbon fiber ribbon structure was prepared with 3 layers, except for the 45-45 orientation, which was constructed with only 2 layers and compared with a 3-layer laminate with a 0-45-45 layer orientation.

[0075] The flexural strength of laminated composites made from untwisted and twisted carbon fiber yarn tapes was measured on a general-purpose testing machine using the ASTM D790 test method, and is summarized in Table 3 below.

[0076] Table 3: Flexural strength of the strips constituting the laminate.

[0077]

[0078] Laminated composites made from fiber-reinforced tapes comprising multiple continuously twisted carbon fiber yarns exhibit lower flexural strength, modulus, and maximum load at failure compared to laminated composites made from tapes with untwisted yarns.

[0079] All orientations of the laminated composite exhibit significantly higher flexibility (flexural modulus) when using twisted fiber yarns, while possessing tensile strength similar to that of untwisted yarn tapes. When used in reinforcing constructions, laminates with twisted fiber yarns will provide greater flexibility in the final construction, while possessing tensile strength comparable to corresponding laminated composites composed of untwisted fiber yarn tapes.

[0080] Therefore, composite materials and laminates prepared with fiber-reinforced strips comprising multiple continuously twisted carbon fiber yarns advantageously possess high tensile strength, but significantly better flexural strength and modulus compared to nearly equivalent composite materials prepared with fiber-reinforced strips having untwisted yarns. This laminated composite material of the present application also has the advantage of reducing the laminate weight for a given strength.

[0081] The bending test according to ASTM D790 includes a span / thickness ratio of 16:1 and a test speed of 0.5 inches per minute. Figure 10 As shown, such tests are performed on a stack of multiple fiber-reinforced strip layers (1010), with the bending position (1012) located at the center of the stack, and the test span supports (1014a, 1014b) result in a span / thickness ratio of 16:1.

[0082] This disclosure only shows and describes certain features and aspects of this disclosure and examples of their versatility. It should be understood that the techniques disclosed herein can be used in a variety of other combinations and environments and can be changed or modified. Therefore, for example, those skilled in the art will recognize or be able to determine many equivalents of the specific substances, procedures, and arrangements described herein using no more than conventional experiments. These equivalents are considered to be within the scope of the invention and are covered by the following claims.

Claims

1. A fiber-reinforced tape comprising: Thermoplastic resins; and Multiple unidirectional continuous fiber yarns embedded in the thermoplastic resin The fiber reinforcement tape has a transverse width ranging from 6 mm to 1525 mm and has 0.1 to 2 yarn ends / mm in the transverse direction; and Each of the plurality of unidirectional continuous fiber yarns contains 1,000 to 100,000 carbon fibers, and each of the plurality of unidirectional continuous fiber yarns has 4 to 400 twists / meter in the length direction.

2. The fiber-reinforced tape of claim 1, wherein, based on the total weight of the fiber-reinforced tape, the fiber-reinforced tape comprises: 5 wt% to 80 wt% of the thermoplastic resin; and The plurality of unidirectional continuous fiber yarns, ranging from 20 wt% to 95 wt%.

3. The fiber-reinforced tape of claim 1, wherein, based on the total weight of the fiber-reinforced tape, the fiber-reinforced tape comprises: 5 wt% to 35 wt% of the thermoplastic resin; and The plurality of unidirectional continuous fiber yarns, ranging from 65 wt% to 95 wt%.

4. The fiber-reinforced tape according to any one of claims 1-3, wherein the thickness of the fiber-reinforced tape is in the range of 0.75 mm to 5 mm.

5. The fiber-reinforced tape according to any one of claims 1-3, wherein the thermoplastic resin comprises a polyolefin.

6. The fiber-reinforced tape according to any one of claims 1-3, wherein the thermoplastic resin comprises polyethylene.

7. The fiber-reinforced tape according to any one of claims 1-3, wherein the thermoplastic resin comprises poly(ethylene-vinyl acetate).

8. The fiber-reinforced tape according to any one of claims 1-3, wherein the fiber-reinforced tape has a porosity in the range of 17% to 47% as determined by computed tomography (CT) scan.

9. The fiber-reinforced tape according to any one of claims 1-3, wherein the fiber-reinforced tape has a tensile elongation in the range of 2% to 10%.

10. The fiber-reinforced tape according to any one of claims 1-3, wherein the fiber-reinforced tape has a strength of 100 g / m². 2 Up to 5,000 g / m 2 Surface density within the range.

11. A fiber-reinforced tape comprising: Thermoplastic resins; and Multiple unidirectional continuous fiber yarns embedded in the thermoplastic resin The plurality of unidirectional continuous fiber yarns include a first twisted fiber yarn and a second twisted fiber yarn, and the first twisted fiber yarn and the second twisted fiber yarn have different twists per meter in the length direction.

12. The fiber-reinforced belt according to claim 11, wherein the first twisted fiber yarn is a carbon fiber yarn.

13. The fiber-reinforced belt according to any one of claims 11-12, wherein the second twisted fiber yarn comprises at least one of glass fiber yarn, aramid fiber yarn, basalt fiber yarn, ultra-high molecular weight polyethylene fiber yarn, liquid crystal polymer fiber yarn, poly(p-phenylene-2,6-benzodioxazole) fiber yarn, cellulose fiber yarn, rayon yarn, or combinations thereof.

14. The fiber-reinforced belt according to any one of claims 11-12, wherein the breaking elongation of the first twisted fiber yarn is substantially the same as the breaking elongation of the second twisted fiber yarn.

15. The fiber-reinforced belt according to any one of claims 11-12, wherein the breaking elongation of the first twisted fiber yarn is within ±10% of the breaking elongation of the second twisted fiber yarn.

16. A composite material comprising layers of two or more fiber-reinforced strips according to any one of the preceding claims.

17. The composite material of claim 16, wherein the layers of the two or more fiber reinforcing strips comprise at least two layers of the fiber reinforcing strips adhered to each other by a thermoplastic resin.

18. The composite material of claim 16, wherein the composite material comprises a layer of a first fiber reinforcing strip and a layer of a second fiber reinforcing strip, wherein the plurality of unidirectional continuous fiber yarns in the first fiber reinforcing strip layer are oriented along a first direction, and the plurality of unidirectional continuous fiber yarns in the second fiber reinforcing strip layer are oriented at an angle greater than 0° and less than or equal to 90° relative to the plurality of unidirectional continuous fiber yarns in the first fiber reinforcing strip layer.

19. The composite material of claim 16, wherein the layer of the two or more fiber reinforcing strips comprises a layer of first fiber reinforcing strips and a layer of second fiber reinforcing strips, wherein the plurality of unidirectional continuous fiber yarns in the layer of first fiber reinforcing strips are oriented along a first direction, and the plurality of unidirectional continuous fiber yarns in the layer of second fiber reinforcing strips are oriented at an angle of about 90° relative to the plurality of unidirectional continuous fiber yarns in the layer of first fiber reinforcing strips.

20. The composite material according to claim 16, wherein the composite material has a flexural strength in the range of 1 MPa to 50 MPa.

21. The composite material according to claim 16, wherein the composite material has a flexural modulus in the range of 0.1 GPa to 15 GPa.

22. A pipe comprising: A reinforcing layer and an outer sheath; wherein the reinforcing layer comprises at least one fiber reinforcing tape according to any one of the preceding claims.

23. The conduit of claim 22, wherein the fiber reinforcement tape is spirally wound along the longitudinal direction of the conduit.

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