Systems and methods for making pre-impregnated continuous fiber tape and fiber tows

Abstract

A system and method for making pre-impregnated continuous fiber tape and fiber tow is disclosed. The system includes: an agitation unit 101 configured to draw a plurality of fibers from a source of material and oscillate the plurality of fibers in a back and forth motion perpendicular to a direction of feed and along a plane of the plurality of fibers to form a plurality of agitated fibers; an impregnation unit 102 configured to impact a metered matrix material onto the moving agitated fibers and pass the agitated fibers through a plurality of fixed split surfaces 304 in the impregnation unit 102 to form an impregnated tape 306; and a consolidation unit 104 including a consolidation die 503, wherein the consolidation die 503 is heated to pass the impregnated tape 306 through the consolidation die 503 and convert the impregnated tape 306 into one or more continuous fiber tows, wherein a plurality of stages in the consolidation die 503 are configured to progressively reduce a cross section of the impregnated tape 306.

Description

[0001] Cross-reference and priority of related applications

[0002] This application claims priority to Indian Patent Application No. 202041034421, filed on August 11, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application generally relates to the field of manufacturing continuously reinforced fibers. More specifically, this application relates to a system and method for preparing pre-impregnated continuous fiber tapes and filaments. Background Technology

[0004] Today, the manufacturing technology of fiber prepregs has made great strides. However, existing continuous fiber reinforcement filament and tape production systems using impregnation mechanisms are also subject to various limitations. Existing systems use large amounts of plastic for reinforcement or impregnation of the fibers in the initial stages. Pultrusion mechanisms are used in existing systems. This results in a large amount of plastic or molten material deposited in the mold or on the walls of the system; the molten material may be a combination of fiber and plastic. Furthermore, this saturated plastic can burn during the preparation of continuous fiber reinforcement tapes or filaments, leading to damage to the mold or system. Therefore, since the shape of the final product depends on the mold, it is necessary to continuously and regularly clean or wipe the plastic and inspect the system for wear. Other limitations include: the inability to control the plastic-to-fiber ratio during large-scale production; the saturation of large amounts of molten plastic in the mold or system; requirements for [specific components]; poor system durability; small product tolerances; and high system cost.

[0005] Therefore, there has long been a need for a system and method for preparing pre-impregnated continuous fiber tapes and filaments to make the repair, reuse and recycling of parts more economical, durable and feasible. Summary of the Invention

[0006] The present invention is intended to introduce concepts related to systems and methods for preparing pre-impregnated continuous fiber tapes and filaments, which are further described in the description. The present invention is not intended to define the essential features of the claims, nor is it intended to define or limit the scope of the claims. This system can be scaled to mass production and can meet on-demand production needs because it is highly customizable.

[0007] In an embodiment, the present application discloses a system for making pre-impregnated continuous fiber tape and fiber strands, the system comprising: an agitation unit configured to draw a plurality of fibers from a material source and oscillate the plurality of fibers in a back and forth motion, perpendicular to the direction of feed and along the plane of the plurality of fibers to form a plurality of agitated fibers; the system further comprising an impregnation unit configured to impinge a metered matrix material onto the moving agitated fibers and pass the agitated fibers through a plurality of fixed splines surfaces in the impregnation unit to form an impregnated tape; the system further comprising a consolidation unit comprising a consolidation die, wherein the consolidation die is heated to pass the impregnated tape through the consolidation die and convert the impregnated tape into one or more continuous fiber strands, wherein a plurality of stages of passages in the consolidation die are configured to gradually reduce the cross-section of the impregnated tape to improve impregnation efficiency.

[0008] In an embodiment, the present application discloses a method for making pre-impregnated continuous fiber tape and fiber strands, comprising: drawing a plurality of fibers from a material source through an agitation unit and oscillating the plurality of fibers in a back and forth motion, perpendicular to the direction of feed and along the plane of the plurality of fibers to form a plurality of agitated fibers; the method further comprising impinging a metered matrix material onto the moving agitated fibers through an impregnation unit and passing the agitated fibers through a plurality of fixed splines surfaces in the impregnation unit to form an impregnated tape; the method further comprising obtaining one or more continuous fiber strands via a consolidation die in a consolidation unit by heating the consolidation die and passing the impregnated tape through a plurality of stages of passages of the consolidation die, the plurality of stages of passages being configured to gradually reduce the cross-section of the impregnated tape to improve impregnation efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0009] The detailed description will be described with reference to the accompanying drawings. In the drawings, the left-most digit of a reference number indicates the first occurrence of the reference number in the drawing. The same numbers are used throughout the drawings to reference like features and components.

[0010] Figure 1 is a system 100 for making pre-impregnated continuous fiber tape and fiber strands according to an embodiment of the present application.

[0011] Figure 2 is an internal view 200 illustrating the agitation unit 101 according to an embodiment of the present application.

[0012] Figure 3 is an internal view 300 illustrating the impregnation unit 102 according to an embodiment of the present application.

[0013] Figure 4 is an internal view illustrating a set of heated kneading rolls 103 according to an embodiment of the present application.

[0014] Figure 5is an internal view 500 of a consolidation unit 104 according to embodiments of the present application.

[0015] Figure 6 is a swivel mechanism 600 according to embodiments of the present application.

[0016] Figure 7 is a method 700 for making pre-impregnated continuous fiber tape and fiber strands according to embodiments of the present application.

[0017] Figure 8 is a perspective view 800 of a plurality of fiber channels 801 in an impregnation unit 102. DETAILED DESCRIPTION

[0018] Reference throughout this specification to "various embodiments", "some embodiments", "one embodiment", or "an embodiment", means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in various embodiments", "in some embodiments", "in one embodiment", or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics can be combined in any suitable manner in one or more embodiments.

[0019] Figure 1 is a system 100 for making pre-impregnated continuous fiber tape and fiber strands according to embodiments of the present application.

[0020] The system 100 for making pre-impregnated continuous fiber tape and fiber strands can include a mixing unit 101, an impregnation unit 102, and a consolidation unit 104. In an embodiment, the mixing unit 101, the impregnation unit 102, and the consolidation unit 104 can be configured to operate continuously in a synchronized manner with each other. In an embodiment, a material source for providing fiber as a raw material to the system 100 can include one or more rolls or similar fiber bales. In an embodiment, the fiber can be carbon or the like. The continuous fiber tape and fiber strands can be made by impregnating a thermoplastic or thermoset material in the fiber. In a preferred embodiment, a thermoplastic can be impregnated in the fiber. In an embodiment, the thermoplastic or impregnation material can be referred to as a matrix material. The use of thermoplastic material to make pre-impregnated continuous fiber tape and fiber strands requires less or no control of the environment in the system 100. The thermoplastic material or matrix makes the repair, reuse, and recycling of 3D printed parts more economical and feasible. While reference is made to the use of thermoplastic material, it can not be limited to the described plastic. Any type of plastic can be used by making specific modifications or adjustments to the environment in the system 100. Some modifications or adjustments can be, but can not be limited to, lower heat, pressure-based matrix injection, flow metering, curing system, etc.

[0021] Reference is now made to Figure 2 is an internal view 200 of the agitation unit 101 according to an embodiment of the present application. In an embodiment, the agitation unit 101 can be configured to create a back-and-forth motion. In an embodiment, the agitation unit 101 is configured to extract the plurality of fibers from the material source and to swing the plurality of fibers in a back-and-forth motion, perpendicular to the direction of feed and along the plane of the plurality of fibers, to form a plurality of agitated fibers at the output of the agitation unit 101. In an embodiment, the agitation unit 101 can include an agitation screw 201, a guide roller 202 and an agitation motor 204. The guide roller 202 can be connected to the agitation screw 201 and the agitation motor 204. The agitation motor can be configured to drive the agitation screw 201 and the guide roller 202 to operate in synchronization. The agitation screw 201 can be configured to rotate, while the guide roller 202 can be configured to swing in a back-and-forth motion to swing the plurality of fibers in a back-and-forth motion over the impregnation unit 102. The back-and-forth motion can diffuse the plurality of fibers and distribute the matrix material over the width of the formed agitated fibers. The back-and-forth motion of the plurality of fibers in the agitation unit 101 can minimize the volume of saturated deposits accumulated in the corners of the impregnation unit 102 to reduce the residence time and thermal degradation of the saturated deposits. Such motion can also induce shear thinning of the matrix material, which can reduce the local viscosity of the matrix material, improve impregnation in the impregnation unit 102, i.e. obtain uniform distribution of the matrix material in the fibers, to improve the quality of the output fibers. In an embodiment, the variable frequency of the agitation unit 101 can be set according to parameters such as the linear velocity of the fibers, the viscosity of the plastic, etc.

[0022] Figure 3is an internal view 300 of the impregnation unit 102 according to embodiments of the present application. The impregnation unit 102 can include one fiber inlet 301, at least two plastic inlets 302, a plurality of fixed split surfaces 304, one or more heaters 303, and one or more mounting holes 305. In an embodiment, the agitated fibers from the agitation unit 101 can enter the impregnation unit 102 through the fiber inlet 301. The agitated fibers can be melted by the heaters 303 at the fiber inlet 301 to minimize the time the agitated fibers are exposed to thermal degradation. The impregnation unit 102 can be configured to impregnate the matrix material on the moving agitated fibers, where the matrix material can be injected into the impregnation unit 102 through the at least two plastic inlets 302. In an embodiment, the plastic inlets 302 can be disposed horizontally apart from each other with the fiber inlet 301 disposed between the two plastic inlets 302. In an embodiment, the matrix material can be metered before being injected into the impregnation unit 102. In other words, metering the matrix material is the calculated amount of matrix material required for the agitated fibers to be immersed or impregnated. Thus, the calculated amount of matrix material, which can be a thermoplastic material, can be injected into the impregnation unit 102 through the plastic inlets 302. In an embodiment, the metering of the matrix material can be achieved by controlling the extrusion speed or the feed screw speed to prevent the buildup of the metered matrix material or the molten material comprising the mixture of the fiber bundle and the metered matrix material. In an embodiment, the saturated deposit can be the molten material. Thus, the metered matrix material can be immersed or impregnated with the agitated fibers in the impregnation unit 102. The impregnation unit 102 can also be configured to pass the agitated fibers through the plurality of fixed split surfaces 304 to form an impregnated band 306. The mounting holes 305 can be used to secure the impregnation unit 102 in the system. In an embodiment, the system 100 utilizes the fixed split surfaces 304 instead of the rollers currently used in existing systems. Since the impregnation unit 102 does not include any moving parts, this provides for convenient and faster manufacturing and prevents the maintenance costs of the rollers, which is more economical. The fixed split surfaces 304 can be configured to drive the matrix material deep into the agitated fibers, distribute the matrix material evenly along the length of the agitated fibers, diffuse the fibers, and increase the tension of the agitated fibers. In an embodiment, the internal surface of the impregnation unit 102 can be coated with a dry lubricating material, such as graphene, to increase the life of the impregnation unit 102 and reduce the friction and fiber shear in the impregnation unit 102.

[0023] Referring to Figure 8 In an embodiment, the impregnation unit 102 can include a plurality of fiber channels 801. This can allow the use of one impregnation unit 102 to develop multiple spools simultaneously. This makes the heat requirement of the impregnation die lower, which makes the setup more economical. In an embodiment, if higher production rates are required, more plastic inlets can be provided towards the end of the impregnation unit 102.

[0024] Figure 5 is an internal view of a consolidation unit 104 according to embodiments of the present application. In an embodiment, the consolidation unit 104 can include a heater box 501, a fiber band inlet 502, a consolidation die 503, a fiber filament outlet 504, and a temperature sensor slot 505. The impregnated band 306 from the impregnation unit 102 can enter the consolidation unit 104 through the fiber band inlet 502. The consolidation die 503 can be heated by the heater box 501 in order to transform the impregnated band 306 into one or more continuous fiber filaments. The consolidation die 503 can include a multi-stage channel configured to gradually reduce the cross-section of the impregnated band 306 to improve impregnation efficiency. Gradual reduction of the cross-section of the impregnated band 306 is necessary to prevent breakage of the continuous fiber filament, which can occur if the cross-section of the impregnated band is directly reduced to the cross-section of the continuous fiber filament. Thus, using a multi-stage channel can allow the impregnated band 306 to be gradually shaped into a circular cross-section that forms the continuous fiber filament without damaging the fibers. This also helps to improve the throughput of the system 100, as the system 100 can be run at a relatively faster speed compared to a single-stage consolidation. Thus, the continuous fiber filament can be obtained from the fiber filament outlet 504. The continuous fiber filament can be circular with an impregnated metering matrix material, such as a thermoplastic. The heater box 501 can be slotted.

[0025] Figure 4 is an internal view of a set of heated kneading rollers 103 according to embodiments of the present application. In an embodiment, the system 100 can optionally include a set of heated kneading rollers 103 configured to provide tension and compaction force to the impregnated band 306 from the impregnation unit 102 to iron out voids present within the impregnated band 306. The set of heated kneading rollers 103 can be disposed between the impregnation unit 102 and the consolidation unit 104. The set of heated kneading rollers 103 can include a stationary roller 403, a rotating roller 404, a compaction spring 401, an axle 405, and a tension adjuster 402. The alignment of the rotating 404 and stationary rollers 403 can be adjusted by the tension adjuster 402 and the compaction spring 401, where the stationary roller 403 is fixed and the rotating roller 404 is movable. The stationary 403 and rotating 404 rollers can be placed close enough to ensure that the matrix material does not fully solidify. However, the stationary 403 and rotating 404 rollers cannot be placed too close so that the material on the surface of the impregnated band 306 can stick to one or both of them. The higher tension provided to the impregnated band 306 by the set of heated kneading rollers 103 can keep the fibers in the impregnated band 306 intact during consolidation. In an embodiment, the set of heated kneading rollers 103 can be heated by, but not limited to, hot air, infrared heating elements, and the like. Such heaters can ensure that the contact with the fiber band does not result in excessive cooling.

[0026] Figure 6is a spooling mechanism 600 according to embodiments of the present application. The spooling mechanism 600 can be a prior art mechanism known in the art. In an embodiment, the spooling mechanism 600 can include a guide 601, a spool 602, a continuous fiber filament 603, a threaded rod 604, a coupler 605, and a stepper motor 607. In an embodiment, the spooling mechanism 600 can be required after the consolidation process in the consolidation unit 104 in order to spool the continuous fiber filament 603 obtained from the consolidation unit 104. The spooling mechanism 600 can collect the continuous fiber filament 603 in a uniform pattern on the spool 602. The guide 601 can oscillate back and forth to wrap the incoming continuous fiber filament 603, which can ensure that the continuous fiber filament does not slip once it can be wound onto the spool 602 and can also ensure that the upper layers of the wound continuous fiber filament 603 do not crush the lower layers. In an embodiment, the spooling mechanism 600 can be monitored by an encoder. The encoder can be configured to monitor the linear speed of the continuous fiber filament 603. In an embodiment, the speed of the stepper motor 607 can be varied as the size of the spool 602 grows to ensure a uniform linear speed. The threaded rod 604 can be configured to rotate to cause the back and forth movement of the guide to distribute the material uniformly on the spool. The coupler 605 can be configured to connect the motor shaft with the threaded rod.

[0027] Figure 7 is a method 700 for preparing a pre-impregnated continuous fiber tape and fiber filament according to embodiments of the present application.

[0028] At step 701, the stirring unit 101 can be configured to draw a plurality of fibers from a source of material, such as a roll of fiber roving, and oscillate the plurality of fibers in a back and forth motion, perpendicular to the direction of feed and along the plane of the plurality of fibers to form a plurality of stirred fibers. In an embodiment, the stirring unit 101 can include a stirring screw 201, a guide roller 202, and a stirring motor 204. The guide roller 202 can be connected to the stirring screw 201 and the stirring motor 204. The stirring motor can be configured to synchronously drive the stirring screw 201 and the guide roller 202. The stirring screw can be configured to rotate, while the guide roller 202 can be configured to oscillate back and forth to oscillate the plurality of fibers in a back and forth motion on the impregnation unit 102. The back and forth motion can spread the plurality of fibers and distribute the matrix material across the width of the formed stirred fibers.

[0029] At step 702, the impregnation unit 102 can be configured to form the impregnated tape 306 by immersing the metered matrix material into the moving agitated fibers and passing the agitated fibers through a plurality of fixed split surfaces 304 in the impregnation unit 102. In an embodiment, the agitated fibers from the agitation unit 101 can enter the impregnation unit 102 through a fiber inlet 301. The agitated fibers can be melted by a heater 303 at the fiber inlet 301 to minimize the time the agitated fibers are exposed to heat degradation. In an embodiment, the plastic inlets 302 can be arranged horizontally apart from each other with the fiber inlet 301 arranged between the two plastic inlets 302. In an embodiment, the matrix material can be metered before being injected into the impregnation unit 102. In other words, the metered matrix material is the calculated amount of matrix material needed for the agitated fibers to immerse or impregnate. Thus, the calculated amount of matrix material, which can be a thermoplastic material, can be injected into the impregnation unit 102 through the plastic inlets 302. Thus, the metered matrix material can immerse or impregnate with the agitated fibers in the impregnation unit 102. The fixed split surfaces 304 can be configured to drive the matrix material into the depth of the agitated fibers, distribute the matrix material evenly along the length of the agitated fibers, diffuse the fibers, and increase the tension of the agitated fibers.

[0030] At step 703, optionally, the set of heated kneading rollers 103 can be configured to provide tension and compaction force to the impregnated tape 306 to iron out the voids present in the impregnated tape 306. The set of heated kneading rollers 103 can be arranged between the impregnation unit 102 and the consolidation unit 104. The set of heated kneading rollers 103 can include a fixed roller 403, a rotating roller 404, a compaction spring 401, and a tension adjuster 402. The fixed roller 403 and the alignment of the fixed roller 403 can be adjusted by the tension adjuster 402 and the compaction spring 401, where the fixed roller 403 is fixed and the rotating roller 404 is movable.

[0031] At step 704, the consolidation die 503 in the consolidation unit 104 can be configured to obtain one or more continuous fiber filaments by heating the consolidation die 503 and passing the impregnated tape 306 through a plurality of stages of passages in the consolidation die 503, which are configured to gradually reduce the cross-section of the impregnated tape 306 to improve the efficiency of impregnation. It is necessary to gradually reduce the cross-section of the impregnated tape 306 to prevent the breakage of the continuous fiber filaments, which can occur if the cross-section of the impregnated tape is directly reduced to the cross-section of the continuous fiber filaments. Thus, using the plurality of stages of passages can gradually shape the impregnated tape 306 to form a circular cross-section of the continuous fiber filaments without damaging the fibers.

[0032] At step 705, after the consolidation process in the consolidation unit 104, the spooling mechanism 600 can be required to wind the continuous fiber yarn 603 obtained from the consolidation unit 104. The spooling mechanism 600 can collect the continuous fiber yarn 603 in a uniform pattern on the spool 602.

[0033] Some embodiments of the present application can include an encoder, a processor or a controller to execute instructions required to configure and control the temperature and other environmental conditions inside the system 100.

[0034] Thus, the system 100 and the method 700 for preparing pre-impregnated continuous fiber tapes and yarns are cost effective and reduce the complexity of large scale production of impregnated continuous fiber tapes and yarns. This is possible because of the metered injection of the matrix material, such as thermoplastic, which not only provides the required calculated amount of matrix material for impregnation with the fibers, but also reduces the saturation of the impregnation unit 102 with a large amount of molten material, improving the ratio of plastic to fiber. The cleaning and wiping process to clear the molten material also improves the durability of the system 100 and various components of the system 100 without being damaged. Further, since the system 100 remains clean by preventing the deposition of molten material, the shape of the impregnated tapes and yarns does not get distorted. All the units in the system 100 can work effectively in series to provide high tolerance impregnated continuous fiber tapes and yarns.

[0035] The embodiments, examples, and alternatives set forth in the preceding paragraphs or in the explanations and drawings, including any one aspect or respective individual feature, can be used independently or in any combination. Features described in relation to one embodiment are applicable to all embodiments, unless the features are incompatible.

[0036] Although the embodiments of the system 100 and the method 700 for preparing pre-impregnated continuous fiber tapes and yarns have been described with specific language relating to structural features and / or methods, it is understood that the claims, which follow, are not necessarily limited to the specific features or methods described. Rather, the specific features and methods are disclosed as embodiments of the system 100 and the method 700 for preparing pre-impregnated continuous fiber tapes and yarns.

Claims

1. A system (100) for preparing pre-impregnated continuous fiber tapes and filaments, characterized in that... The system includes: The stirring unit (101) is configured to extract multiple fibers from the material source and swing the multiple fibers in a back-and-forth motion perpendicular to the feeding direction and along the plane of the multiple fibers to form multiple stirred fibers. The impregnation unit (102) is configured to impinge metering matrix material onto moving, agitated fibers and pass the agitated fibers through a plurality of fixed slit surfaces (304) in the impregnation unit (102) to form an impregnation band (306); and The consolidation unit (104) includes a consolidation mold (503), wherein the consolidation mold (503) is heated to allow the impregnated tape (306) to pass through the consolidation mold (503) and to convert the impregnated tape (306) into one or more continuous filaments, wherein the multi-level channels in the consolidation mold (503) are configured to gradually reduce the cross-section of the impregnated tape (306) to improve impregnation efficiency.

2. The system (100) according to claim 1, characterized in that, The system also includes a set of heated kneading rollers (103) configured to provide tension and pressure to the impregnation belt (306) to iron out voids present in the impregnation belt (306), wherein the set of heated kneading rollers (103) is disposed between the impregnation unit (102) and the consolidation unit (104).

3. The system (100) according to claim 1, characterized in that, The metering matrix material is a thermoplastic or thermosetting material.

4. The system (100) according to claim 1, characterized in that, The stirring unit (101) includes a guide roller (202) configured to oscillate the multiple fibers in a back-and-forth motion, wherein the guide roller (202) is connected to a stirring screw (201) and a stirring motor (204).

5. The system (100) according to claim 1, characterized in that, The impregnation unit (102) includes one or more heaters (303) and at least two plastic inlets (302) configured to inject the metering matrix material into the impregnation unit (102), wherein the plastic inlets (302) are arranged horizontally apart from each other, and a fiber inlet (301) is located between the two plastic inlets (302) and configured to convey the stirred fibers from the stirring unit (101) to the impregnation unit (102), wherein the metering matrix material is obtained by controlling the extrusion speed or the feed screw speed to prevent the accumulation of the metering matrix material or a molten material comprising fiber bundles and a mixture thereof.

6. The system (100) according to claim 2, characterized in that, The heated kneading rollers (103) include a fixed roller (403), a rotating roller (404), a compaction spring (401), and a tension regulator (402), wherein the alignment of the rotating roller (404) and the fixed roller (403) is adjusted by the tension regulator (402) and the compaction spring (401), wherein the fixed roller (403) is stationary and the rotating roller (404) is movable.

7. The system (100) according to claim 1, characterized in that, The consolidation unit (104) includes a heater box (501) with slots.

8. The system (100) according to claim 1, characterized in that, The stirred fibers are melted at the fiber inlet (301) of the impregnation unit (102) to minimize the time the stirred fibers are exposed to thermal degradation.

9. The system (100) according to claim 1, characterized in that, The continuous filaments are circular.

10. The system (100) according to claim 1, characterized in that, The impregnation unit (102) includes multiple fiber channels (801), which allows multiple spools to be developed simultaneously using one impregnation unit (102), thereby reducing the heat requirements of the impregnation unit (102) and making the setup more economical.

11. The system according to claim 1, characterized in that, The inner surface of the impregnation unit (102) is coated with a dry lubricating material to increase the lifespan of the impregnation unit (102) and reduce friction and fiber shearing in the impregnation unit (102).

12. The system according to claim 1, characterized in that, The variable frequency of the stirring unit (101) is set according to the linear velocity of the fiber and the viscosity of the plastic.

13. A method (700) for preparing pre-impregnated continuous fiber tapes and filaments, comprising: Multiple fibers are extracted from the material source by the stirring unit (101), and the multiple fibers are oscillated back and forth, perpendicular to the feeding direction and along the plane of the multiple fibers, to form multiple stirred fibers. The metering matrix material is impacted onto the moving, agitated fibers by the impregnation unit (102), and the agitated fibers are passed through a plurality of fixed slit surfaces (304) in the impregnation unit (102) to form an impregnation strip (306). One or more continuous filaments are obtained by heating the consolidation mold (503) in the consolidation unit (104) and passing the impregnation strip (306) through the multi-level channels of the consolidation mold (503), wherein the multi-level channels are configured to gradually reduce the cross-section of the impregnation strip (306) to improve impregnation efficiency.

14. The method (700) according to claim 13, characterized in that, Tension and pressure are provided by a set of heated kneading rollers (103) in the system (100) to iron out voids present in the impregnation belt (306), wherein the set of heated kneading rollers (103) is disposed between the impregnation unit (102) and the consolidation unit (104).

15. The method (700) according to claim 13, characterized in that, The impregnation unit (102) includes one or more heaters (303) and at least two plastic inlets (302) configured to inject the metering matrix material into the impregnation unit (102), wherein the plastic inlets (302) are arranged horizontally apart from each other, and a fiber inlet (301) is located between the two plastic inlets (302) and configured to convey the stirred fibers from the stirring unit (101) to the impregnation unit (102), wherein the metering matrix material is obtained by controlling the extrusion speed or the feed screw speed to prevent the accumulation of the metering matrix material or a molten material comprising fiber bundles and a mixture thereof.

16. The method (700) according to claim 13, characterized in that, The stirred fibers are melted at the fiber inlet (301) of the impregnation unit (102) to minimize the time the stirred fibers are exposed to thermal degradation.

17. The method (700) according to claim 13, characterized in that, The continuous filaments are circular.

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