Preparation method of composite core material capable of being internally provided with load structure units in partitioned mode and composite core material

Abstract

The invention discloses a preparation method of a composite core material capable of being internally provided with load structure units in a partitioned mode and the composite core material. Basic unit core rods are arranged in all corner wheel penetrating holes in a penetrating mode, second fibers are arranged on all yarn storage devices, the ends of all the basic unit core rods and the ends of all the second fibers are bundled and then dragged through a traction device, and the load structure units are arranged in the load structure units in a partitioned mode; then synchronously controlling the corner wheels to rotate by a first angle in the same direction, enabling the yarn storage devices filled in the notches of the corner wheels to rotate along with the corresponding corner wheels, synchronously controlling the driving plates to reversely rotate by a second angle, and enabling the yarn storage devices filled in the notches of the driving plates to rotate along with the corresponding driving plates; circulating for multiple times to obtain an integral fiber braid layer filled with each basic unit core rod; and arranging a packaging sheath layer on the outer side of the fiber integral braid layer to obtain the composite core material. The composite core material can give full play to axial mechanical properties, has good flexibility and resilience folding and unfolding characteristics, has outstanding comprehensive mechanical properties such as tensile resistance, bending resistance, compression resistance and impact resistance, and is relatively simple and efficient in forming process.

Description

Technical Field

[0001] The present invention belongs to the technical field of composite core material preparation, and particularly relates to a method for preparing a composite core material with a partitioned built-in load structure unit and a composite core material. Background Art

[0002] At present, solid core rod composite materials are mostly prepared by pultrusion process, the combination of pultrusion and winding, or the combination of pultrusion and braided sleeve. Most of the fibers inside are arranged parallel to the axis. Without additional protection, the static mechanical properties in other directions except the axial direction are not fully utilized, and the dynamic mechanical properties are poor. In addition, although the solid core rod composite materials prepared by the combination of pultrusion and winding wrap the axial unidirectional fibers with a winding layer, and the solid core rod composite materials prepared by the combination of pultrusion and braided sleeve wrap the axial unidirectional fibers with a braided sleeve layer, both of these two processes form a "skin-core structure". In this structure, it is difficult for the "skin" layer to effectively restrain the crack propagation in the "core" layer structure, resulting in poor comprehensive mechanical properties, especially the dynamic mechanical properties.

[0003] Patent CN1898085B discloses an aluminum conductor composite core reinforced cable and its preparation method. The ACCC cable has a composite core surrounded by an external film and at least one layer of aluminum conductor. The composite core includes multiple fibers in one or more matrix materials, and the fibers are from at least one fiber type. The fibers inside the single-rod type composite core material exemplified by patent CN1898085B are all in a unidirectional arrangement structure. Such composite core materials are highly sensitive to stress concentration. Especially in the surface layer, they are easily affected by stress concentration, resulting in damage penetration, or are easily separated at the interfaces of different materials inside and expand rapidly over a large range, that is, crack propagation. The transmission wires equipped with such composite core materials must use a customized terminal joint clamping system for construction. Compared with the conventional level, there are differences in construction efficiency, difficulty and cost. The key of the customized terminal joint clamping system lies in designing a conical inner cavity and a bushing based on the axis of the composite core material, and decomposing all the vertical pressures of the fittings originally along the diameter direction of the composite core material into partial vertical pressures and axial tensions by using the conical inclined surface. The fittings are part of the customized terminal joint clamping system, and the axial tension specifically refers to the surface friction force between the fittings and the composite core material. In addition, the bending and flexible rebound properties of such composite core materials are easily restricted by their own diameter structure, which is also a challenge for the bulk storage and supply transportation of products.

[0004] Patent US8250845B2 relates to a composite twisted pair wire formed by impregnating carbon fibers with a thermoplastic resin, and provides a fiber composite twisted pair wire, which is a cable with a 1×n structure. The cable is formed by impregnating a carbon fiber bundle with a thermosetting resin and then twisting multiple stranded wires. Each stranded wire is formed by covering the outer periphery of the carbon fiber bundle with fibers and then curing and heat-treating by applying a thermosetting resin. Taking the stranded composite core material in Patent US8250845B2 as an example, by twisting several small-diameter single-rod core materials into a large-diameter core material, compared with the single-rod composite core material, it not only has similar characteristics, but also significantly improves the bending performance, can achieve bending and winding with a smaller radius, and the bending and flexible rebound performance is more prominent. This is mainly attributed to the existence of a fiber winding layer on the surface of the basic unit core rod, secondly, the multi-strand stranded structure decomposes the axial tensile performance of the basic unit core rod in any direction within the space between the axial direction and the diameter, and thirdly, there is a small amount of relative displacement space between the basic unit core rods after multi-strand stranding. However, such core materials have relatively high requirements for the fine control of the forming process. For example, the two-step method requires precise control of the semi-curing and secondary full-curing temperature ranges of the resin, while the one-step method may have extremely high requirements for the coupling degree of process control and equipment operation. The forming quality of each process section of the basic unit core rod before and after stranding directly determines the comprehensive performance of the complete core material. Affected by the stranded structure, there is a certain loss in the utilization rate of the material mechanical properties in the basic unit core rod, the unevenness on the surface of the stranded composite core material is extremely high, the risk of triggering stress concentration and failure is increased, and the requirements for the clamping system are also increased accordingly. In addition, the stranded composite core material also has the possibility of "lantern"-type loosening.

[0005] Patent US9633766B2 discloses an energy-saving conductor with a reduced thermal inflection point and its manufacturing method, which relates to an electrical conductor for electric power transmission and distribution. It has prestress adjustment for the strength member, such that the conductive material of aluminum, aluminum alloy, copper, copper alloy or copper micro-alloy is substantially tension-free or under compressive stress in the conductor, while the strength member is under tensile stress before the wire is strung, resulting in a lower thermal inflection point in the wire. Taking the aluminum-clad composite core material in Patent US9633766B2 as an example, a layer of aluminum is coated on the single-rod composite core material. To a certain extent, this aluminum layer can improve the bending resistance of the single-rod composite core material, physically isolate the single-rod composite core material, provide environmental weather protection, further enhance the power transmission capacity of the power transmission wire, and at the same time be compatible with the construction requirements of the metal core clamping system. However, the contact effect between the aluminum layer and the single-rod composite core material is crucial for the forming quality of the aluminum-clad composite core material. If the gap between the aluminum layer and the single-rod composite core material is too large, it is easy to cause the position offset between the aluminum layer and the single-rod composite core material and uneven stress; if the gap between the aluminum layer and the single-rod composite core material is too small, it is easy to cause the aluminum layer to squeeze and abrade the single-rod composite core material; in addition, the burrs on the inner surface of the aluminum layer may damage the surface of the single-rod composite core material; and there is a certain risk of achieving absolute closure between the aluminum layer and the single-rod composite core material, and there may be a situation where the residual liquid or gas medium erodes the single-rod composite core material; moreover, the high temperature during the aluminum layer coating is likely to ablate the resin on the single-rod composite core material, exposing the fibers. Since the density orders of magnitude of the fibers and the resin are similar, ablation defects are difficult to detect by means such as vision, ultrasound, and ray without dissection. The ablation defects remaining inside the aluminum layer will become a major hidden danger inducing product service failure.

[0006] As structural lightweight strengthening members, the above-mentioned various advanced composite core materials mainly utilize their outstanding axial tensile resistance, fatigue resistance, and low thermal expansion and deformation properties. However, the continuous long-span application and the variable and complex service environment pose more stringent requirements on their comprehensive mechanical properties, flexible retraction and release capabilities, and low-cost storage and transportation. The above-mentioned single-rod composite core material performs outstandingly in axial performance. However, since the main load-bearing fibers are only distributed axially, its performance in aspects such as ultimate bending resistance, ultimate shear resistance, and ultimate compressive resistance is seriously insufficient and must rely on a customized terminal joint clamping system to make up for it. In addition, its impact resistance and crack propagation resistance are relatively weaker, the flexible resilience of the overall core material is poor, the bending radius is large, and the collection and transportation costs are relatively high. The above-mentioned stranded composite core material improves the bending performance to a certain extent by finely distributing the basic load units, but this may sacrifice some axial performance, and the forming process becomes complicated, the preparation cost increases, and the basic units are unevenly stressed along the axis. Summary of the Invention

[0007] In view of the above-mentioned defects of the prior art, the present invention provides a method for preparing a composite core material with a partitioned built-in load structure unit and a composite core material. The composite core material can not only fully exert the axial mechanical properties, but also has good flexibility, resilience and retraction characteristics, and also has outstanding comprehensive mechanical properties such as tensile resistance, bending resistance, compression resistance and impact resistance. The molding process is relatively simple and efficient, and it is expected to form a systematic preparation process standard for industry products.

[0008] The technical solution adopted by the present invention to solve its technical problem is: A method for preparing a composite core material with a partitionable built-in load structure unit is prepared by using a preparation system for the composite core material, the preparation system comprising an integral weaving device, the integral weaving device comprising a base and a plurality of angle wheels, a dial and a yarn storage device, six angle wheel cutouts are evenly distributed on the edge of the angle wheel and an angle wheel perforation is provided in the middle, two dial cutouts are symmetrically distributed on the edge of the dial, n circles of angle wheels are distributed on the base from the inside to the outside, the first circle of the angle wheel is one, the i-th circle of the angle wheels is 6´(i-1), 2≤i≤n, the multiple angle wheels in the i-th circle are evenly distributed and the center connection line is a regular hexagon, each angle wheel cutout of each angle wheel is filled with a yarn storage device, each angle wheel cutout of each angle wheel is arranged relative to the corresponding angle wheel cutout of the corresponding adjacent angle wheel, and the yarn storage devices in the two oppositely arranged angle wheel cutouts are respectively filled with two dial cutouts of a dial at the same time; The preparation method comprises the following steps: S1. First, respectively insert a basic unit core rod made of the first fiber and the first resin into the perforation of each of the angle wheels, and arrange the second fiber on each of the yarn storage devices, and then bundle the ends of each of the basic unit core rods and each of the second fibers and pull them through a traction device, and then synchronously control each of the angle wheels to rotate in the same direction by a first angle, and the yarn storage device filled in the cutout of each of the angle wheels rotates along with the corresponding angle wheel, and then synchronously control each of the dials to rotate in the opposite direction by a second angle, and the yarn storage device filled in the cutout of each of the dials rotates along with the corresponding dial, and after multiple cycles, an integral fiber braided layer filled with each of the basic unit core rods is obtained; S2. Arrange a packaging sheath layer outside the fiber integral braided layer to obtain a composite core material.

[0009] Furthermore, the preparation system further comprises a pay-off frame, a pre-split frame and a packaging and extruding device, wherein the pre-split frame is provided with a plurality of pre-split holes, and the pay-off frame, the pre-split frame, the overall weaving device and the packaging and extruding device are arranged in sequence from upstream to downstream; The following steps are also included before step S1: using the first fiber and the first resin to prepare the basic unit core rod through a pultrusion process, and winding the basic unit core rod on a winding reel; In step S1: First, arrange multiple winding reels with the basic unit mandrels on the pay-off stand, and then pass the basic unit mandrels on each winding reel through the corresponding pre-splitting holes and the corresponding angle wheel perforations in sequence; In step S2: Set the encapsulation sheath layer outside the fiber overall braided layer through the encapsulation extrusion device.

[0010] Furthermore, In step S1: The first fiber is one of carbon fiber, aramid fiber, basalt fiber, glass fiber, polyimide fiber, silicon carbide fiber, liquid crystal polymer fiber, ultra-high molecular weight polyethylene fiber, and carbon nanotube fiber; the first resin is a thermosetting resin or a thermoplastic resin; the second fiber is one of polyester fiber, aramid fiber, glass fiber, nylon fiber, liquid crystal polymer fiber, and polyimide fiber; In step S2: The material of the encapsulation sheath layer is the second resin, specifically including one of polyester resin, liquid crystal polymer resin, polyimide resin, polyphenylene sulfide resin, polyether ether ketone resin, and silicone resin.

[0011] Furthermore, In step S1: The diameter of the basic unit mandrel is controlled within 0.7 - 3.8 mm, several basic unit mandrels are arranged in each angle wheel perforation, and several bundles of the second fiber are arranged on each yarn accumulator; In step S2: The thickness of the encapsulation sheath layer is controlled within 0.3 - 2 mm, and the encapsulation sheath layer penetrates into the fiber overall braided layer by a certain thickness.

[0012] Furthermore, three circles of angle wheels are distributed from the inside to the outside on the base, and five circles of dials are distributed from the inside to the outside. Among them, both the first circle of dial layer and the second circle of dial layer include six dials, the third circle of dial layer includes eighteen dials, the fourth circle of dial layer includes twelve dials, and the fifth circle of dial layer includes thirty dials.

[0013] Furthermore, In step S1: The first fiber is carbon fiber with a tensile strength of not less than 5400 MPa, the first resin is epoxy resin and the tensile strength of the epoxy resin casting body is not less than 70 MPa, and the temperature in the pultrusion process is controlled at 150 - 200 °C; the diameter of the basic unit mandrel is 1 mm, the volume content of carbon fiber in the basic unit mandrel is controlled at 65 - 70%, the porosity of the basic unit mandrel is less than or equal to 1.5%, the axial tensile strength is not less than 2100 MPa and the tensile elastic modulus is not less than 120 GPa; the second fiber is liquid crystal polymer fiber and the thickness of the liquid crystal polymer fiber is 3000 D; the first angle is 60° and each first angle wheel rotates clockwise, the second angle is 180° and each dial rotates counterclockwise; In step S2: The material of the encapsulation sheath layer is liquid crystal polymer resin and the thickness of the encapsulation sheath layer is 1.5 mm, and the encapsulation sheath layer penetrates into the fiber overall braided layer by 0.66 mm.

[0014] Furthermore, the preparation system further includes an infrared drying oven and a tube heating device. The infrared drying oven is arranged between the pre-wiring frame and the overall braiding device, and the tube heating device is arranged between the overall braiding device and the encapsulation extrusion device. The infrared drying oven is used to dry and dehumidify the basic unit mandrel before entering the overall braiding device, and the tube heating device is used to dry and dehumidify the fiber mandrel overall braided body before entering the encapsulation extrusion device.

[0015] Furthermore, each of the angle wheel notches is composed of two arcs and one of the arcs coincides with the edge of the corresponding angle wheel, and each of the dial notches is composed of two arcs and one of the arcs coincides with the edge of the corresponding dial; the angle wheel is driven to rotate by a supporting angle wheel driving motor, and the dial is driven to rotate by a supporting dial driving motor.

[0016] A preparation system for a composite core material, which is used to implement the preparation method of the composite core material with a partitioned built-in load structure unit described above, includes a wire pay-off frame, a pre-wiring frame, an infrared drying oven, an overall braiding device, a tube heating device, and an encapsulation extrusion device arranged in sequence from upstream to downstream.

[0017] A composite core material with a partitioned built-in load structure unit is prepared by using the preparation method of the composite core material with a partitioned built-in load structure unit described above, and includes a fiber overall braided layer. A number of basic unit mandrels are respectively filled in the partitioned holes of the fiber overall braided layer. An encapsulation sheath layer is coated outside the fiber overall braided layer, and the encapsulation sheath layer penetrates into the fiber overall braided layer by a certain thickness.

[0018] Compared with the prior art, the beneficial effects of the present invention are: The preparation method of the composite core material with a partitionable built-in load structure unit in the present invention includes the following steps: S1. First, insert the basic unit core rods into the perforations of each corner wheel respectively, and arrange the second fibers on each yarn storage device respectively. Then, bundle the ends of each basic unit core rod and each second fiber and pull them by a traction device. Then, synchronously control each corner wheel to rotate in the same direction by a first angle. The yarn storage devices filled at the cutouts of each corner wheel rotate along with the corresponding corner wheel. Then, synchronously control each dial to rotate in the opposite direction by a second angle. The yarn storage devices filled at the cutouts of each dial rotate along with the corresponding dial. After repeating the cycle for multiple times, an overall woven body of the fiber core rod is obtained. The overall woven body of the fiber core rod includes an overall woven layer of fibers. Each basic unit core rod is filled in the corresponding partition holes of the overall woven layer of fibers respectively; S2. Set an encapsulation sheath layer outside the overall woven layer of fibers to obtain the composite core material. The present invention proposes to use the overall woven layer of fibers as the assembly carrier for each basic unit core rod, and fill each small-sized basic unit core rod in the corresponding partition holes of the overall woven layer of fibers as required, so as to obtain a large-sized overall woven body of the fiber core rod. The basic unit core rods filled in the partition holes of the overall woven layer of fibers do not participate in the weaving and are distributed along the axial direction of the composite core material. In this way, the prepared composite core material can give full play to its axial mechanical properties. The overall woven layer of fibers has the following effects on each basic unit core rod: providing a radial holding force to constrain the basic unit core rods in each partition hole into a whole; performing spatial layout segmentation to provide relatively more movable micro-spaces for the composite core material during load deformation; weakening the strain in the inner and outer bending arc ranges when the composite core material is bent, reducing the risk of breakage and failure; effectively alleviating the large rigid compression load directly borne by the basic unit core rods instantaneously when the composite core material is radially compressed, thereby reducing the triggering risk of compression splitting failure. The present invention additionally sets an encapsulation sheath layer outside the overall woven layer of fibers to achieve functions such as encapsulation isolation, secondary holding and shaping, preventing the overall woven layer of fibers from being damaged and loosened, enhancing insulation and heat resistance. At the same time, under the synergistic effect of the encapsulation sheath layer, the overall woven layer of fibers and the basic unit core rods, when a certain point on the surface of the composite core material is subjected to an impact load, the encapsulation sheath layer, the overall woven layer of fibers and the built-in basic unit core rods near this point will act together to quickly absorb and transfer the remaining energy after the deformation of the composite core material to the basic unit core rods in other partitions. Through the energy absorption and filtering of each layer of material, the internal energy transfer and the deformation counterpunch of the basic unit core rods, the maximum unloading of the impact load is achieved, thereby reducing the vibration frequency of the composite core material and effectively reducing the internal fatigue risk and prolonging the service life. In summary, the prepared composite core material can not only give full play to its axial mechanical properties, but also has good flexible rebound and retraction characteristics, and also has outstanding comprehensive mechanical properties such as anti-tensile, anti-bending, anti-compression and anti-impact. Moreover, the forming process is relatively simple and efficient. Description of the Drawings

[0019] Figure 1Schematic structural diagram of the preparation system for the composite core material in the present invention; Figure 2 is Figure 1 Schematic side view structure diagram of the overall weaving device in; Figure 3 is Figure 2 Enlarged structural diagram of one of the corner wheels in; Figure 4 is Figure 2 Enlarged structural diagram of one of the dials in; Figure 5 is Figure 2 Schematic diagram of each ring of the dial layers in; Figure 6 Internal structural diagram of the composite core material in the present invention; Figure 7 is Figure 6 Schematic side view structure diagram of.

[0020] Explanation of the reference numerals in the figure: 1. Overall weaving device, 101. Corner wheel, 10101. Corner wheel perforation, 10102. Corner wheel notch, 102. Dial, 10201. Dial notch, 10301. First ring of dial layers, 10302. Second ring of dial layers, 10303. Third ring of dial layers, 10304. Fourth ring of dial layers, 10305. Fifth ring of dial layers; 2. Composite core material, 201. Basic unit core rod, 202. Fiber overall weaving layer, 203. Encapsulation sheath layer, 3. Pay-off stand, 4. Pre-distribution stand, 5. Infrared drying oven, 6. Tube-type heating device, 7. Encapsulation extrusion device, 8. Take-up reel. Specific embodiments

[0021] The following further elaborates in detail on the specific embodiments of the present invention with reference to the accompanying drawings. These embodiments are only used to illustrate the present invention and are not intended to limit the present invention.

[0022] In the description of the present invention, it should be noted that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0025] A method for preparing a composite core material with a partitionable built-in load structure unit is prepared by using a composite core material preparation system, such as Figure 1 and Figure 2 As shown, the preparation system includes an integral weaving device 1, which includes a base and a plurality of angle wheels 101, a dial 102 and a yarn storage device. Six angle wheel cutouts 10102 are evenly distributed around the edge of the angle wheel 101 and an angle wheel perforation 10101 is provided in the middle. Figure 3 , two dial cutouts 10201 are symmetrically distributed around the edge of the dial 102, see Figure 4 , n circles of angle wheels are distributed on the base from the inside to the outside, the first circle has one angle wheel, the i-th circle has 6´(i-1) angle wheels, 2≤i≤n, the multiple angle wheels 101 of the i-th circle are evenly distributed and the center connecting line is a regular hexagon, each angle wheel cutout 10102 of each angle wheel 101 is filled with a yarn storage device, each angle wheel cutout 10102 of each angle wheel 101 is arranged relative to the corresponding angle wheel cutout 10102 of the corresponding adjacent angle wheel 101, and the yarn storage devices in the two oppositely arranged angle wheel cutouts 10102 are respectively filled with two dial cutouts 10201 of a dial 102 at the same time; wherein Figure 3 The circle A of the middle angle wheel cutout 10102 is used to arrange the yarn storage device, wherein Figure 4 The circle B of the middle dial cutout 10201 is also used to arrange the yarn storage device; The preparation method comprises the following steps: S1. First, respectively insert a basic unit core rod 201 made of a first fiber and a first resin into each corner wheel perforation 10101, and arrange a second fiber on each yarn storage device, and then bundle the ends of each basic unit core rod 201 and each second fiber and pull them through a pulling device, then synchronously control each corner wheel 101 to rotate in the same direction by a first angle, and the yarn storage device filled in each corner wheel cutout 10102 rotates together with the corresponding corner wheel 101, and then synchronously control each dial 102 to rotate in the opposite direction by a second angle, and the yarn storage device filled in each dial cutout 10201 rotates together with the corresponding dial 102, and after multiple cycles, a fiber integral braided layer 202 filled with each basic unit core rod 201 is obtained; S2. A packaging sheath layer 203 is arranged outside the overall fiber braided layer 202 to obtain a composite core material 2, as shown in Figure 6 and Figure 7 .

[0026] The present invention proposes to use the overall fiber braided layer 202 as an assembly carrier for each basic unit core rod 201. The small-sized basic unit core rods 201 are respectively filled in the corresponding partition holes of the overall fiber braided layer 202 according to requirements, and a large-sized overall fiber braided body of the fiber core rod is obtained. The basic unit core rods 201 filled in the partition holes of the overall fiber braided layer 202 do not participate in the braiding and are axially distributed along the composite core material. In this way, the prepared composite core material 2 can give full play to its axial mechanical properties. The overall fiber braided layer 202 has the following functions for each basic unit core rod 201: providing a radial holding force to constrain the basic unit core rods 201 in each partition hole into a whole; performing spatial layout segmentation to provide relatively more movable micro-spaces for the composite core material 2 during load deformation; weakening the strain in the inner and outer bending arc ranges when the composite core material 2 bends, reducing the risk of breakage failure; effectively alleviating the large rigid compression load directly borne by the basic unit core rod 201 instantaneously when the composite core material 2 is radially compressed, thereby reducing the triggering risk of compression splitting failure. Specifically, there are movable micro-spaces between the basic unit core rods 201 in the partition holes of the overall fiber braided layer 202, which is beneficial to improving the mechanical properties such as bending, impact resistance, and compression resistance of the final composite core material 2.

[0027] In the present invention, the basic unit core rod 201 filled in the overall fiber braided layer 202 is a conventional pultruded composite core rod. By unifying the process parameters of the basic unit core rod 201, it is convenient for the industry to consider product standardization and can reduce the performance of the final composite core material 2 caused by the large differences in the preparation technical routes of the composite core material 2. The present invention additionally arranges a packaging sheath layer 203 outside the overall fiber braided layer 202 to achieve functions such as packaging isolation, secondary holding and shaping, preventing the overall fiber braided layer 202 from being damaged and loosened, enhancing insulation and heat resistance. At the same time, under the synergistic action of the packaging sheath layer 203, the overall fiber braided layer 202 and the basic unit core rod 201, when a certain point on the surface of the composite core material 2 is subjected to an impact load, the packaging sheath layer 203, the overall fiber braided layer 202 and the built-in basic unit core rod 201 near this point will act together to quickly absorb and transfer the remaining energy after the deformation of the composite core material 2 to the basic unit core rods 201 in other partitions. Through the energy absorption and filtering of each layer of material, the internal energy transfer and the deformation counteraction of the basic unit core rod 201, the maximum unloading of the impact load is realized, thereby reducing the vibration frequency of the composite core material 2, effectively reducing the internal fatigue risk, and extending the service life.

[0028] Among them, each corner wheel notch 10102 is composed of two arcs, and one of the arcs coincides with the edge of the corresponding corner wheel 101. Each dial notch 10201 is composed of two arcs, and one of the arcs coincides with the edge of the corresponding dial 102. The corner wheel 101 is driven to rotate by a supporting corner wheel 101 driving motor, and the dial 102 is driven to rotate by a supporting dial 102 driving motor.

[0029] Among them, as Figure 1 shown, the preparation system further includes a wire pay-off frame 3, a pre-wiring frame 4 and a packaging extrusion device 7. The pre-wiring frame 4 is provided with a plurality of pre-wiring holes. The wire pay-off frame 3, the pre-wiring frame 4, the integral braiding device 1 and the packaging extrusion device 7 are arranged in sequence from upstream to downstream.

[0030] Before step S1, the following steps are further included: using a first fiber and a first resin and preparing a basic unit mandrel 201 through a pultrusion process, and winding the basic unit mandrel 201 on a winding disc. In step S1: First, arrange a plurality of winding discs loaded with the basic unit mandrels 201 on the wire pay-off frame 3, and then sequentially pass the basic unit mandrels 201 on each winding disc through the corresponding pre-wiring holes and the corresponding corner wheel through-holes 10101. In step S2: A packaging sheath layer 203 is arranged outside the fiber integral braiding layer 202 through the packaging extrusion device 7.

[0031] In one embodiment, In step S1: The first fiber is one of carbon fiber, aramid fiber, basalt fiber, glass fiber, polyimide fiber, silicon carbide fiber, liquid crystal polymer fiber, ultra-high molecular weight polyethylene fiber and carbon nanotube fiber; the first resin is a thermosetting resin or a thermoplastic resin; the second fiber is one of polyester fiber, aramid fiber, glass fiber, nylon fiber, liquid crystal polymer fiber and polyimide fiber. In step S2: The material of the packaging sheath layer 203 is a second resin, specifically including one of polyester resin, liquid crystal polymer resin, polyimide resin, polyphenylene sulfide resin, polyether ether ketone resin and silicone resin.

[0032] Among them, In step S1: The diameter of the basic unit mandrel 201 is controlled within 0.7 - 3.8 mm. Preferably, the diameter of the basic unit mandrel 201 is controlled within 1 - 2 mm. A plurality of basic unit mandrels 201 are inserted into each corner wheel through-hole 10101, and a plurality of bundles of the second fiber are arranged on each yarn accumulator. In step S2: The thickness of the packaging sheath layer 203 is controlled within 0.3 - 2 mm, and the packaging sheath layer 203 penetrates into the fiber integral braiding layer 202 by a certain thickness.

[0033] Preferably, As Figure 5 shown, there are three circles of corner wheels distributed from the inside to the outside on the base and five circles of dials distributed from the inside to the outside. Among them, there are a total of nineteen corner wheels. Among them, both the first circle of dial layer 10301 and the second circle of dial layer 10302 include six dials 102, the third circle of dial layer 10303 includes eighteen dials 102, the fourth circle of dial layer 10304 includes twelve dials 102, and the fifth circle of dial layer 10305 includes thirty dials 102; In step S1: The first fiber is carbon fiber with a tensile strength of 5630 MPa, the first resin is epoxy resin and the tensile strength of the epoxy resin casting reaches 75 MPa. The temperature in the pultrusion process is controlled at 150 - 200 °C; the diameter of the basic unit mandrel 201 is 1 mm, the volume content of carbon fiber in the basic unit mandrel 201 is controlled at 65 - 70%, the porosity of the basic unit mandrel 201 is less than or equal to 1.5%, the axial tensile strength is greater than or equal to 2100 MPa and the tensile elastic modulus is greater than or equal to 120 GPa. Among them, fifteen basic unit mandrels 201 are inserted into the corner wheel perforation 101 at the center position of the base, and five basic unit mandrels 201 are inserted into each corner wheel perforation 101 at other positions of the base. A total of 105 basic unit mandrels 201 are inserted on the base; the second fiber is liquid crystal polymer fiber and the thickness of the liquid crystal polymer fiber is 3000 D; the first angle is 60° and each first corner wheel rotates clockwise, the second angle is 180° and each dial 102 rotates counterclockwise, and the braiding angle is 18°; In step S2: The material of the encapsulation sheath layer 203 is liquid crystal polymer resin and the thickness of the encapsulation sheath layer 203 is 1.5 mm. The encapsulation sheath layer 203 penetrates into the fiber overall braided layer 202 by 0.66 mm, and the thickness of the encapsulation sheath layer 203 on the surface of the fiber overall braided layer 202 is 0.84 mm.

[0034] The tensile strength of the obtained composite core material 2 reaches 2970 MPa, the tensile modulus reaches 138 GPa, the bending radius can be realized to be not less than 36 times the diameter of the composite core material, it can be normally elastically restored without damage, its bending fatigue life can reach at least 200,000 times, and after low-speed impact, the tensile performance of the composite core material 2 can continue to maintain above 80% of the normal level, showing excellent flexibility. Under the condition of 25% damage tolerance, the composite core material 2 can still maintain normal load service until triggering inspection and maintenance to eliminate potential hazards.

[0035] In one embodiment, the preparation system further includes an infrared drying oven 5 and a tube heating device 6. The infrared drying oven 5 is arranged between the pre-splitting frame 4 and the integral braiding device 1, and the tube heating device 6 is arranged between the integral braiding device 1 and the encapsulation extrusion device 7. The infrared drying oven 5 is used to dry and dehumidify the basic unit mandrel 201 before it enters the integral braiding device 1, and the tube heating device 6 is used to dry and dehumidify the integral braided body of the fiber mandrel before it enters the encapsulation extrusion device 7.

[0036] As Figure 1 shown, a preparation system for a composite core material is used to implement the preparation method of the composite core material with a partitioned built-in load structure unit as described above, and includes a wire pay-off stand 3, a pre-splitting frame 4, an infrared drying oven 5, an integral braiding device 1, a tube heating device 6, and an encapsulation extrusion device 7 arranged in sequence from upstream to downstream.

[0037] As Figure 6 and Figure 7 shown, a composite core material with a partitioned built-in load structure unit is prepared by using the preparation method of the composite core material with a partitioned built-in load structure unit as described above, and includes a fiber integral braided layer 202. A number of basic unit mandrels 201 are respectively filled in the partitioned holes of the fiber integral braided layer 202, and an encapsulation sheath layer 203 is coated outside the fiber integral braided layer 202, and the encapsulation sheath layer 203 penetrates into the fiber integral braided layer 202 to a certain thickness.

[0038] In this way, the encapsulation sheath layer 203 plays a role in protecting, weather resistance, encapsulating the surface of the fiber integral braided layer 202, and synergistically improving the impact resistance and compression resistance of the composite core material.

[0039] This composite core material is applicable to the tension core in power transmission conductors, the tension cables of building facilities, and the main load-bearing components of the anchoring cables of deep-sea platforms, etc.

[0040] The present invention defines the size, material system, and forming process route of the basic unit mandrel 201 in the target composite core material 2, which is convenient for the industry to achieve standardization and mass production, and effectively reduces the risk of quality problems caused by the variable material system and complex structure process during the preparation of the composite core material 2.

[0041] In summary, this composite core material 2 can not only give full play to the axial mechanical properties, but also has good flexible rebound and retractable characteristics, and also has outstanding comprehensive mechanical properties such as anti-tensile, anti-bending, anti-compression, and anti-impact. Moreover, the forming process is relatively simple, which is beneficial to improving the preparation efficiency and reducing the preparation cost.

[0042] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and substitutions can be made, and these improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a composite core material with a partitionable built-in load structure unit, the method comprising using a composite core material preparation system for preparation, the preparation system comprising an integral braiding device (1), the integral braiding device (1) comprising a base and a plurality of angle wheels (101), a dial (102) and a yarn storage device, the edge of the angle wheel (101) being evenly distributed with six angle wheel cutouts (10102), the edge of the dial (102) being symmetrically distributed with two dial cutouts (10201), the base being distributed with n circles of angle wheels from the inside to the outside, the first circle of the angle wheels being one, the i-th circle of the angle wheels being symmetrically distributed with n circles of angle wheels, There are 6´(i-1) wheels, 2≤i≤n, the multiple corner wheels (101) of the i-th circle are evenly distributed and the center connecting line forms a regular hexagon, each corner wheel cutout (10102) of each corner wheel (101) is filled with a yarn storage device, each corner wheel cutout (10102) of each corner wheel (101) is arranged opposite to the corresponding corner wheel cutout (10102) of the corresponding adjacent corner wheel (101), and the yarn storage devices in the two oppositely arranged corner wheel cutouts (10102) are respectively filled with two dial cutouts (10201) of a dial (102), characterized in that: Each of the corner wheels (101) is provided with a corner wheel through hole (10101) in the middle; The preparation method comprises the following steps: S1, firstly inserting a basic unit core rod (201) made of a first fiber and a first resin into each of the perforations (10101) of the angle wheels, and arranging a second fiber on each of the yarn storage devices, and then pulling the ends of each of the basic unit core rods (201) and each of the second fibers by a pulling device after being bundled, and then synchronously controlling each of the angle wheels (101) to rotate in the same direction by a first angle, so that the yarn storage device filled at each of the angle wheel cutouts (10102) rotates together with the corresponding angle wheel (101), and then synchronously controlling each of the dials (102) to rotate in the opposite direction by a second angle, so that the yarn storage device filled at each of the dial cutouts (10201) rotates together with the corresponding dial (102), and after multiple cycles, a fiber integral braided layer (202) filled with each of the basic unit core rods (201) is obtained; S2. Arranging a packaging sheath layer (203) outside the fiber integral braided layer (202) to obtain a composite core material (2).

2. The method for preparing a composite core material with partitionable built-in load structure unit according to claim 1, characterized in that: The preparation system further comprises a pay-off frame (3), a pre-split frame (4) and a packaging and extruding device (7), wherein the pre-split frame (4) is provided with a plurality of pre-split holes, and the pay-off frame (3), the pre-split frame (4), the overall braiding device (1) and the packaging and extruding device (7) are arranged in sequence from upstream to downstream; Before step S1, the following steps are also included: using the first fiber and the first resin to prepare the basic unit core rod (201) through a pultrusion process, and winding the basic unit core rod (201) on a winding reel; In step S1: firstly, a plurality of winding reels equipped with the basic unit mandrels (201) are arranged on a pay-off frame (3), and then the basic unit mandrels (201) on each winding reel are sequentially passed through the corresponding pre-splitting holes and the corresponding angle wheel through holes (10101); In step S2: a packaging sheath layer (203) is provided on the outside of the fiber integral braided layer (202) by means of the packaging extrusion device (7).

3. The method for preparing a composite core material with partitionable built-in load structure unit according to claim 1, characterized in that: In step S1: the first fiber is one of carbon fiber, aromatic polyamide fiber, basalt fiber, glass fiber, polyimide fiber, silicon carbide fiber, liquid crystal polymer fiber, ultra-high molecular weight polyethylene fiber and carbon nanotube fiber; the first resin is a thermosetting resin or a thermoplastic resin; the second fiber is one of polyester fiber, aramid fiber, glass fiber, nylon fiber, liquid crystal polymer fiber and polyimide fiber; In step S2: the material of the packaging sheath layer (203) is a second resin, specifically comprising one of polyester resin, liquid crystal polymer resin, polyimide resin, polyphenylene sulfide resin, polyetheretherketone resin and silicone resin.

4. The method for preparing a composite core material with partitionable built-in load structure unit according to claim 1, characterized in that: In step S1: the diameter of the basic unit core rod (201) is controlled to be 0.7-3.8 mm, a plurality of basic unit core rods (201) are inserted into each of the angle wheel perforations (10101), and a plurality of bundles of second fibers are arranged on each of the yarn storage devices; In step S2: the thickness of the packaging sheath layer (203) is controlled to be 0.3-2 mm, and the packaging sheath layer (203) penetrates into the fiber integral braided layer (202) to a certain thickness.

5. The method for preparing a composite core material with partitionable built-in load structure unit according to claim 2, characterized in that: The base is provided with three circles of angle wheels from the inside to the outside and five circles of dials from the inside to the outside, wherein the first circle of dials (10301) and the second circle of dials (10302) each include six dials (102), the third circle of dials (10303) includes eighteen dials (102), the fourth circle of dials (10304) includes twelve dials (102), and the fifth circle of dials (10305) includes thirty dials (102).

6. The method for preparing a composite core material with partitionable built-in load structure unit according to claim 5, characterized in that: In step S1: the first fiber is a carbon fiber with a tensile strength greater than or equal to 5400 MPa, the first resin is an epoxy resin and the tensile strength of the epoxy resin casting is greater than or equal to 70 MPa, the temperature in the pultrusion process is controlled at 150-200°C; the diameter of the basic unit core rod (201) is 1 mm, the volume content of the carbon fiber in the basic unit core rod (201) is controlled at 65-70%, the porosity of the basic unit core rod (201) is less than or equal to 1.5%, the axial tensile strength is greater than or equal to 2100 MPa and the tensile elastic modulus is greater than or equal to 120 GPa; the second fiber is a liquid crystal polymer fiber and the thickness of the liquid crystal polymer fiber is 3000D; the first angle is 60° and each first angle wheel rotates clockwise, the second angle is 180° and each dial (102) rotates counterclockwise; In step S2: the material of the packaging sheath layer (203) is liquid crystal polymer resin and the thickness of the packaging sheath layer (203) is 1.5 mm, and the packaging sheath layer (203) penetrates 0.66 mm into the fiber integral braided layer (202).

7. The method for preparing a composite core material with partitionable built-in load structure unit according to claim 2, characterized in that: The preparation system further comprises an infrared drying oven (5) and a tubular heating device (6); the infrared drying oven (5) is arranged between the pre-split frame (4) and the overall weaving device (1); the tubular heating device (6) is arranged between the overall weaving device (1) and the packaging and extrusion device (7); the infrared drying oven (5) is used to dry and dehumidify the basic unit core rod (201) before entering the overall weaving device (1); and the tubular heating device (6) is used to dry and dehumidify the overall braided body of the fiber core rod before entering the packaging and extrusion device (7).

8. The method for preparing a composite core material with partitionable built-in load structure unit according to claim 1, characterized in that: Each of the corner wheel cutouts (10102) is composed of two arcs, one of which coincides with the edge of the corresponding corner wheel (101); each of the dial cutouts (10201) is composed of two arcs, one of which coincides with the edge of the corresponding dial (102); the corner wheel (101) is driven to rotate by a matching corner wheel (101) driving motor, and the dial (102) is driven to rotate by a matching dial (102) driving motor.

9. A composite core material preparation system, used to implement the composite core material preparation method of the partitionable built-in load structure unit according to any one of claims 1 to 8, characterized in that: It comprises a pay-off frame (3), a pre-splitting frame (4), an infrared drying box (5), an integral weaving device (1), a tubular heating device (6) and a packaging and extruding device (7) which are arranged in sequence from upstream to downstream.

10. A composite core material with a partitionable built-in load structure unit, prepared by the method for preparing a composite core material with a partitionable built-in load structure unit according to any one of claims 1 to 8, characterized in that: It comprises a fiber integral braided layer (202), wherein each partition hole of the fiber integral braided layer (202) is respectively filled with a plurality of basic unit core rods (201), and the outer side of the fiber integral braided layer (202) is coated with a packaging sheath layer (203), and the packaging sheath layer (203) penetrates into the fiber integral braided layer (202) to a certain thickness.

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