Wire for fiber-reinforced plastic stranded cable, stranded cable having wire, and apparatus and method for manufacturing wire

Abstract

An embodiment of the present invention provides a wire for a fiber-reinforced plastic stranded cable, a stranded cable comprising the wire, and an apparatus and method for manufacturing the wire, the wire comprising: a main body including a fiber bundle impregnated with a resin; and a thermoplastic fiber layer formed to surround the outer circumferential surface of the main body, wherein the resin of the main body is semi-cured by heat treatment, and the thermoplastic fiber layer is cut to prevent the semi-cured resin of the main body from passing through the thermoplastic fiber layer when cooled after the heat treatment. An effect of the present invention is that it is capable of providing a wire for a fiber-reinforced plastic stranded cable, a stranded cable comprising the wire, and an apparatus and method for manufacturing the wire, wherein the wire has not only excellent tensile strength but also excellent flexibility and transportability, without performing an unstock process that forcibly separates wires from each other to enable a core wire, a side wire, and side wires to move independently without being bonded to each other after a thermosetting resin is cured by the heat treatment in the stranded cable.

Description

A strand for a fiber-reinforced plastic stranded cable, a stranded cable having the strand, an apparatus for manufacturing the strand, and a method for manufacturing the strand.

[0001] The present invention relates to a stranded wire for a stranded cable, a stranded cable having the stranded wire, an apparatus for manufacturing the stranded wire, and a method for manufacturing the stranded wire. More specifically, the invention relates to a stranded wire for a fiber-reinforced plastic stranded cable, a stranded cable having the stranded wire, an apparatus for manufacturing the stranded wire, and a method for manufacturing the stranded wire.

[0002] A stranded-pair cable is structured such that multiple side wires are arranged to twist around a core wire. The wires can be made of steel or fiber bundles. Recently, wires for stranded-pair cables are being made of fiber bundles, such as carbon fiber reinforced plastic (CFRP), which is a fiber bundle reinforced with a material like resin.

[0003] Stranded cables made of carbon fiber reinforced plastic wires are used in various fields such as the aerospace, automotive, sporting goods, construction, and bridges, as they possess high lightness and elasticity compared to stranded cables made of steel wires, while also exhibiting high strength, heat resistance, corrosion resistance, and electrical conductivity.

[0004] Stranded-pair cables made of fiber-reinforced plastic wires are manufactured by stranding fiber bundles impregnated with a material such as a thermosetting resin to form wires, then stranding multiple wires together, and finally curing the thermosetting resin through heat treatment. However, during this process, there was a problem in which air or residual solvent contained in the thermosetting resin remained as gaps inside the cable between the process of impregnating the fiber bundles with the thermosetting resin and the process of stranding multiple wires to form the stranded cable, resulting in a degradation of mechanical properties such as the tensile strength of the stranded cable.

[0005] Conventionally, in order to solve these problems, Japanese Patent Publication No. JP 2-127583 disclosed a method of winding fiber yarns at high density around the outer surface of a wire impregnated with a thermosetting resin and then twisting multiple wires together to discharge air or residual solvent contained inside the twisted cable by the pressure of the wound fiber yarns. However, during the twisting process, the uncured liquid thermosetting resin is woven out between the wound fiber yarns and seeps into the gaps between the core wire and the side wires and the gaps between the side wires. As the thermosetting resin seeping into the gaps is cured during the curing process, the core wire, the side wires, and the side wires are bonded together and hardened into a rigid rod. As a result, the twisted cable has very low flexibility, which causes transportation problems requiring large reels with large-diameter winding barrels.

[0006] Conventionally, to solve these problems, US Patent Publication US 8,250,845 B2 disclosed a stranded cable having excellent tensile strength, flexibility, and transportability by impregnating a carbon fiber bundle with a thermosetting resin, then stranding a plurality of wires formed by coating the outer surface of the carbon fiber bundle with fibers, then curing the thermosetting resin by heat treatment to form a stranded cable, and then undergoing an unstuck process to forcibly separate the wires so that the core wire, side wire, and side wires joined together do not join together and behave independently. However, there is a problem in that additional equipment is required to perform the unstuck process to forcibly separate the wires so that the core wire, side wire, and side wires behave independently without joining together in a stranded cable in which the thermosetting resin is cured by heat treatment, and the stranded cable is damaged during the unstuck process.

[0007] One problem that the present invention aims to solve is to provide a fiber-reinforced plastic stranded cable wire having excellent tensile strength, flexibility, and transportability without performing an unstuck process that forcibly separates the wires so that the core wire, side wires, and side wires behave independently without being joined to each other after the thermosetting resin is cured by heat treatment in the stranded cable, a stranded cable having said wire, an apparatus for manufacturing said wire, and a method for manufacturing said wire.

[0008] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below.

[0009] A wire for a fiber-reinforced plastic stranded cable according to one embodiment of the present invention comprises: a main body including a fiber bundle impregnated with resin; and a thermoplastic fiber layer formed to surround the outer surface of the main body; wherein the resin of the main body is semi-cured by heat treatment, and the thermoplastic fiber layer is hardened by cooling after heat treatment so that the semi-cured resin of the main body does not pass through the thermoplastic fiber layer.

[0010] A stranded cable having a strand for a fiber-reinforced plastic stranded cable according to another embodiment of the present invention comprises a main body including a fiber bundle impregnated with resin and a plurality of strands including a thermoplastic fiber layer formed to surround the outer surface of the main body, and is formed by stranding the strands and then curing the resin by heat treatment, wherein the resin of the main body is semi-cured by heat treatment, and the thermoplastic fiber layer is hardened by cooling after heat treatment so that the semi-cured resin of the main body does not pass through the thermoplastic fiber layer, and then the plurality of strands are stranded and the semi-cured resin is cured by heat treatment.

[0011] A manufacturing apparatus for a wire for a fiber-reinforced plastic stranded cable according to another embodiment of the present invention comprises: a supply device for supplying a fiber bundle; an impregnation device for impregnating the supplied fiber bundle with resin; a fiber layer forming device for forming a thermoplastic fiber layer to surround the outer surface of the fiber bundle impregnated with resin; a curing device for semi-curing the resin impregnated in the fiber bundle by heat treatment; and a winding device for winding a wire formed by cooling after heat treatment so that the thermoplastic fiber layer hardens so that the semi-cured resin does not pass through the thermoplastic fiber layer.

[0012] A method for manufacturing a wire for a fiber-reinforced plastic stranded cable according to another embodiment of the present invention comprises: a supply step of supplying a fiber bundle; an impregnation step of impregnating the supplied fiber bundle with a resin; a fiber layer forming step of forming a thermoplastic fiber layer to surround the outer surface of the fiber bundle impregnated with resin; a curing step of partially curing the resin impregnated in the fiber bundle by heat treatment; and a winding step of winding a wire formed by cooling after heat treatment so that the thermoplastic fiber layer hardens so that the partially cured resin does not pass through the thermoplastic fiber layer.

[0013] One effect of the present invention is to provide a fiber-reinforced plastic stranded cable wire having excellent tensile strength, flexibility, and transportability without performing an unstuck process that forcibly separates the wires so that the core wire, side wires, and side wires behave independently without being joined to each other after the thermosetting resin is cured by heat treatment in the stranded cable, a stranded cable having said wire, an apparatus for manufacturing said wire, and a method for manufacturing said wire.

[0014] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description below.

[0015] FIG. 1 is a cross-sectional view showing a wire for a fiber-reinforced plastic stranded cable according to one embodiment of the present invention.

[0016] FIG. 2 is a diagram comparing the cross-sections of a wire for a fiber-reinforced plastic stranded cable and a wire without a thermoplastic fiber layer, according to one embodiment of the present invention.

[0017] FIG. 3 is a cross-sectional view showing a stranded cable having a wire for a fiber-reinforced plastic stranded cable according to another embodiment of the present invention.

[0018] FIG. 4 is a schematic diagram showing a manufacturing apparatus for a wire for a fiber-reinforced plastic stranded cable according to another embodiment of the present invention.

[0019] FIG. 5 is a flowchart illustrating a method for manufacturing a wire for a fiber-reinforced plastic stranded cable according to another embodiment of the present invention.

[0020] Specific details for implementing the invention are explained based on examples. These examples are provided as illustrative examples to enable a person skilled in the art to understand specific details for implementing the invention and may be modified in various other forms; therefore, the scope of the invention is not limited by the following examples.

[0021] Furthermore, the terms used in this specification are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise.

[0022] In this specification, terms such as “comprising” or “having” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should not be understood as precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0023] 1. Wire for fiber-reinforced plastic stranded cables

[0024] The present embodiment relates to a wire for a fiber-reinforced plastic stranded cable. As illustrated in FIG. 1, the wire (100) for a fiber-reinforced plastic stranded cable according to the present embodiment may include a main body (110) and a thermoplastic fiber layer (120).

[0025] The main body (110) includes a bundle of fibers impregnated with resin.

[0026] The fiber may be a fiber applicable to fiber-reinforced plastic stranded cables, such as glass fiber, carbon fiber, aramid, basalt fiber, etc.

[0027] The fiber bundle may be 1,200 tex to 2,400 tex glass fiber, 3,000 strands to 24,000 strands carbon fiber, 200 denier to 3,000 denier aramid, or 60 tex to 4,200 tex basalt fiber, and the quantity may be applied according to the weight per unit length (g / m).

[0028] The resin may be a thermoplastic resin or a thermosetting resin. Thermoplastic resins may include polypropylene resin, polyethylene resin, polycarbonate resin, poly(methyl methacrylate) (PMMA) resin, etc. Thermosetting resins may include epoxy resin, polyester resin, polyurethane resin, etc. The resin content may be 15% to 35% by weight relative to the weight of the fiber. If the resin content is less than 15% by weight relative to the weight of the fiber, it is difficult to fully impregnate the fiber bundle, and if it exceeds 35% by weight, it may be excessively discharged to the outer surface of the fiber bundle.

[0029] The resin is semi-cured by heat treatment. The heat treatment can be carried out in an oven 2 to 10 m long while maintaining a temperature of 100 to 150°C.

[0030] The thermoplastic fiber layer (120) is formed to surround the outer surface of the main body (110). The thermoplastic fiber layer (120) functions to protect the resin-impregnated fiber bundle of the main body (110).

[0031] The thermoplastic fiber layer (120) is hardened by cooling after the resin of the main body (110) is partially hardened by heat treatment, so that the partially hardened resin of the main body (110) does not pass through the thermoplastic fiber layer (120).

[0032] The thermoplastic fiber layer (120) can be formed in various ways. For example, the thermoplastic fiber layer (120) can be formed by applying fibers such as polypropylene, polyethylene, or polyester to the outer surface of a main body (110) containing fiber bundles impregnated with resin to form an outer layer.

[0033] The thermoplastic fiber layer (120) can be formed by applying 1 to 10 fibers having a denier of 2,000 to 15,000 to the outer surface of the main body (110).

[0034] The thermoplastic fiber layer (120) may have a thickness of 0.2 mm to 1.0 mm. If the thermoplastic fiber layer (120) has a thickness of less than 0.2 mm, it is not possible to prevent the resin impregnated in the fiber bundle of the main body (110) from being discharged to the outside in a semi-cured state, and if it has a thickness of more than 1.0 mm, it may be difficult to twist the wire of the main body (110).

[0035] According to such a fiber-reinforced plastic stranded cable wire, the resin of the main body (110) is partially cured by heat treatment, and then the thermoplastic fiber layer (120) is hardened by cooling. Since the partially cured resin of the main body (110) does not pass through the thermoplastic fiber layer (120), bubbles or residual solvent inside the wire (100) are discharged due to the pressure of the thermoplastic fiber layer (120), so as well as excellent tensile strength, the flexibility and transportability are excellent due to the partially cured resin inside the wire (100).

[0036] As shown in Fig. 2 for example, the wire with a simple fiber layer instead of the thermoplastic fiber layer shown in Fig. 2 (a) has a hardened internal resin and has an elliptical cross-section, which is less flexible, whereas the wire with the thermoplastic fiber layer shown in Fig. 2 (b) has a semi-hardened internal resin and has a circular cross-section, which is excellent flexible.

[0037] In addition, when manufacturing a stranded cable by twisting multiple such wires and then curing the resin through heat treatment, the semi-cured resin is not discharged through the thermoplastic fiber layer (120) during the stranding process. Consequently, the semi-cured resin does not seep into the gaps between the core wire and the side wires and the gaps between the side wires. As a result, the core wire and the side wires are not bonded to each other during the curing process, and the side wires are not bonded to each other, allowing the wires to be separated and behave independently. Therefore, a stranded cable equipped with such fiber-reinforced plastic stranded cable wires exhibits superior tensile strength, flexibility, and transportability compared to a stranded cable without such wires, even without performing an unstuck process that forcibly separates the bonded wires to behave independently.

[0038] 2. A stranded cable having strands for a fiber-reinforced plastic stranded cable

[0039] The present embodiment relates to a stranded cable having strands for a fiber-reinforced plastic stranded cable. As illustrated in FIG. 3, the stranded cable (200) having strands for a fiber-reinforced plastic stranded cable according to the present embodiment may include a core strand (100'') and a plurality of side strands (100').

[0040] The core wire (100'') is a wire arranged at the center of the stranded cable (200).

[0041] A plurality of side wires (100') surround a core wire (100'') and consist of six. Although six side wires (100') are shown in FIG. 3, this embodiment is not necessarily limited to this, and there may be seven or more side wires (100'). The plurality of side wires (100') are arranged to wrap around a core wire (100'') while twisting spirally around a single core wire (100'').

[0042] The wire (100', 100''), including the core wire (100'') and the side wire (100'), comprises a main body and a thermoplastic fiber layer.

[0043] The main body comprises a fiber bundle impregnated with resin, and a thermoplastic fiber layer is formed to surround the outer surface of the main body.

[0044] In this embodiment, the wire (100', 100'') is identical to the wire for the fiber-reinforced plastic stranded cable described above, so redundant descriptions regarding the main body and the thermoplastic resin layer, etc. are omitted.

[0045] After a plurality of side wires (100') are stranded around a core wire (100”), a semi-cured resin is cured by heat treatment.

[0046] According to a stranded cable equipped with such fiber-reinforced plastic stranded cables, the semi-cured resin inside the strands is not discharged through the thermoplastic fiber layer during the stranding process, so the semi-cured resin does not seep into the gap (201) between the core strands and the side strands and the gap (201) between the side strands. Consequently, during the curing process, the core strands and the side strands are not bonded to each other, and the side strands are not bonded to each other, allowing the strands to be separated from each other and behave independently. Therefore, compared to a stranded cable without such strands, a stranded cable equipped with such fiber-reinforced plastic stranded cables exhibits superior tensile strength, flexibility, and transportability without the need for an unstuck process that forcibly separates bonded strands to behave independently.

[0047] 3. Manufacturing apparatus for strands for fiber-reinforced plastic stranded cables

[0048] The present embodiment relates to a manufacturing apparatus for a strand of fiber reinforced plastic stranded cable. As illustrated in FIG. 4, the manufacturing apparatus (300) for a strand of fiber reinforced plastic stranded cable according to the present embodiment may include a supply device (310), an impregnation device (320), a fiber layer forming device (350), a curing device (360), and a winding device (370). Furthermore, the manufacturing apparatus (300) for a strand of fiber reinforced plastic stranded cable according to the present embodiment may further include a guide plate (330) and a preform mold (340).

[0049] The supply device (310) is a device that supplies fiber bundles.

[0050] The fiber may be a fiber applicable to fiber-reinforced plastic stranded cables, such as glass fiber, carbon fiber, aramid, basalt fiber, etc.

[0051] The fiber bundle may be 1,200 tex to 2,400 tex glass fiber, 3,000 strands to 24,000 strands carbon fiber, 200 denier to 3,000 denier aramid, or 60 tex to 4,200 tex basalt fiber, and the quantity may be applied according to the weight per unit length (g / m).

[0052] The impregnation device (320) is a device for impregnating a supplied fiber bundle with resin.

[0053] The resin may be a thermoplastic resin or a thermosetting resin. Thermoplastic resins may include polypropylene resin, polyethylene resin, polycarbonate resin, poly(methyl methacrylate) (PMMA) resin, etc. Thermosetting resins may include epoxy resin, polyester resin, polyurethane resin, etc. The resin content may be 15% to 35% by weight relative to the weight of the fiber. If the resin content is less than 15% by weight relative to the weight of the fiber, it is difficult to fully impregnate the fiber bundle, and if it exceeds 35% by weight, it may be excessively discharged to the outer surface of the fiber bundle.

[0054] The guide plate (330) is a device that corrects the arrangement of fiber bundles so that they do not get twisted together, and maintains tension as the fiber bundles pass through multi-stage circular holes. The number of holes can be varied, and the number of holes can be adjusted according to the quantity of fiber bundles being fed in, or it can be set so that two fiber bundles are fed into each hole.

[0055] The preform mold (340) can be manufactured within a range of ø to ø to match the diameter of the wire to be made. The preform mold (340) may be equipped with a heater rod to increase the semi-curing and impregnation properties of the resin. For example, the heater rod may be controlled to maintain a temperature within a range of 40°C to 100°C.

[0056] The fiber layer forming device (350) is a device for forming a thermoplastic fiber layer to surround the outer surface of a fiber bundle impregnated with resin.

[0057] The thermoplastic fiber layer is formed to surround the outer surface impregnated with resin. The thermoplastic fiber layer functions to protect the resin-impregnated fiber bundle.

[0058] The thermoplastic fiber layer hardens upon cooling after the resin has been partially cured by heat treatment, preventing the partially cured resin from penetrating the thermoplastic fiber layer.

[0059] The thermoplastic fiber layer can be formed in various ways. For example, the thermoplastic fiber layer can be formed by applying fibers such as polypropylene, polyethylene, or polyester to the outer surface of a fiber bundle impregnated with resin to form an outer layer.

[0060] The thermoplastic fiber layer can be formed by wrapping 1 to 10 fibers having a denier of 2,000 to 15,000 around the outer surface of a fiber bundle.

[0061] The thermoplastic fiber layer may have a thickness of 0.2 mm to 1.0 mm. If the thermoplastic fiber layer is less than 0.2 mm thick, it may not be possible to prevent the resin impregnated in the fiber bundle from being discharged to the outside in a semi-cured state, and if it is more than 1.0 mm thick, it may be difficult to strand the wires.

[0062] The rotational speed for forming the thermoplastic fiber layer can be set in the range of 5 rpm to 120 rpm in proportion to the line speed.

[0063] The curing device (360) is a device that partially cures the resin impregnated in the fiber bundle by heat treatment. The heat treatment can be carried out in an oven 2 m to 10 m long while maintaining a temperature of 100°C to 150°C.

[0064] After heat treatment, cooling causes the thermoplastic fiber layer to harden so that the semi-cured resin does not pass through the thermoplastic fiber layer, thereby forming a wire.

[0065] The winding device (370) is a device for winding wires formed by cooling after heat treatment so that the thermoplastic fiber layer hardens so that the semi-cured resin does not pass through the thermoplastic fiber layer.

[0066] The winding spool size of the winding device (370) is determined according to the degree of bending of the wire. For example, the diameter of the core can be selected within the range of 300 mm to 1,200 mm to select an appropriate size so as to cause minimal damage to the wire.

[0067] According to the manufacturing apparatus for wires for fiber-reinforced plastic stranded cables, the resin is semi-cured by heat treatment and then the thermoplastic fiber layer hardens by cooling, so that the semi-cured resin does not pass through the thermoplastic fiber layer. Consequently, air bubbles or residual solvent inside the wire are discharged due to the pressure of the thermoplastic fiber layer, resulting in excellent tensile strength, as well as excellent flexibility and transportability due to the semi-cured resin inside the wire.

[0068] During the stranding process of the fiber-reinforced plastic stranded cable wires manufactured by the above-described manufacturing device, the semi-cured resin inside the wires is not discharged through the thermoplastic fiber layer. Consequently, the semi-cured resin does not permeate into the gaps between the core wire and the side wires, nor between the side wires. As a result, during the curing process, the core wire and the side wires do not bond to each other, and the side wires do not bond to each other, allowing the wires to separate and behave independently. Therefore, compared to a stranded cable without such wires, a stranded cable equipped with these fiber-reinforced plastic stranded cable wires exhibits superior tensile strength, flexibility, and transportability without the need for an unstuck process that forcibly separates bonded wires to behave independently.

[0069] 4. Method for manufacturing strands for fiber-reinforced plastic stranded cables

[0070] The present embodiment relates to a method for manufacturing a wire for a fiber-reinforced plastic stranded cable. As illustrated in FIG. 5, the method for manufacturing a wire for a fiber-reinforced plastic stranded cable according to the present embodiment (S400) may include a supply step (S410), an impregnation step (S420), a fiber layer formation step (S430), a curing step (S440), and a winding step (S450).

[0071] The supply step (S410) is a step of supplying fiber bundles. The fibers may be fibers applicable to fiber-reinforced plastic stranded cables, such as glass fibers, carbon fibers, aramid, basalt fibers, etc. The fiber bundles may be glass fibers with 1,200 tex to 2,400 tex, carbon fibers with 3,000 strands to 24,000 strands, aramid fibers with 200 denier to 3,000 denier, and basalt fibers with 60 tex to 4,200 tex, and the quantity may be applied according to the weight per unit length (g / m).

[0072] The impregnation step (S420) is a step of impregnating the supplied fiber bundle with resin.

[0073] The resin may be a thermoplastic resin or a thermosetting resin. Thermoplastic resins may include polypropylene resin, polyethylene resin, polycarbonate resin, poly(methyl methacrylate) (PMMA) resin, etc. Thermosetting resins may include epoxy resin, polyester resin, polyurethane resin, etc. The resin content may be 15% to 35% by weight relative to the weight of the fiber. If the resin content is less than 15% by weight relative to the weight of the fiber, it is difficult to fully impregnate the fiber bundle, and if it exceeds 35% by weight, it may be excessively discharged to the outer surface of the fiber bundle.

[0074] Meanwhile, it may further include a guide step that corrects the arrangement so that the fiber bundles do not twist each other, and maintains tension as the fiber bundles pass through a multi-stage circular hole.

[0075] In addition, it may include a preform mold step that is manufactured to match the diameter of the wire to be produced.

[0076] The fiber layer formation step (S430) is a step of forming a thermoplastic fiber layer to surround the outer surface of a fiber bundle impregnated with resin.

[0077] The thermoplastic fiber layer is formed to surround the outer surface impregnated with resin. The thermoplastic fiber layer functions to protect the resin-impregnated fiber bundle.

[0078] The thermoplastic fiber layer hardens upon cooling after the resin has been partially cured by heat treatment, preventing the partially cured resin from penetrating the thermoplastic fiber layer.

[0079] The thermoplastic fiber layer can be formed in various ways. For example, the thermoplastic fiber layer can be formed by applying fibers such as polypropylene, polyethylene, or polyester to the outer surface of a fiber bundle impregnated with resin to form an outer layer.

[0080] The thermoplastic fiber layer can be formed by wrapping 1 to 10 fibers having a denier of 2,000 to 15,000 around the outer surface of a fiber bundle.

[0081] The thermoplastic fiber layer may have a thickness of 0.2 mm to 1.0 mm. If the thermoplastic fiber layer is less than 0.2 mm thick, it may not be possible to prevent the resin impregnated in the fiber bundle from being discharged to the outside in a semi-cured state, and if it is more than 1.0 mm thick, it may be difficult to strand the wires.

[0082] The rotational speed for forming the thermoplastic fiber layer can be set in the range of 5 rpm to 120 rpm in proportion to the line speed.

[0083] The curing step (S440) is a step of partially curing the resin impregnated in the fiber bundle by heat treatment.

[0084] Heat treatment can be performed in an oven 2 to 10 m long while maintaining a temperature of 100 to 150°C. After heat treatment, cooling causes the thermoplastic fiber layer to harden so that the semi-cured resin does not pass through the thermoplastic fiber layer, thereby forming a wire.

[0085] The winding step (S450) is a step of winding a wire formed by cooling after heat treatment so that the thermoplastic fiber layer hardens so that the semi-cured resin does not pass through the thermoplastic fiber layer.

[0086] The size of the winding spool in the winding step (S450) is determined according to the degree of bending of the wire. For example, the diameter of the core can be selected within the range of 300 mm to 1,200 mm to select an appropriate size so as to cause minimal damage to the wire.

[0087] According to the method for manufacturing a wire for a fiber-reinforced plastic stranded cable, the resin is semi-cured by heat treatment and then the thermoplastic fiber layer hardens by cooling, so the semi-cured resin does not pass through the thermoplastic fiber layer. Consequently, air bubbles or residual solvent inside the wire are discharged due to the pressure of the thermoplastic fiber layer, resulting in excellent tensile strength, as well as excellent flexibility and transportability due to the semi-cured resin inside the wire.

[0088] The present invention can be used for a stranded cable wire, a stranded cable having the stranded wire, an apparatus for manufacturing the stranded wire, and a method for manufacturing the wire.

Claims

1. A main body comprising a fiber bundle impregnated with resin; and A thermoplastic fiber layer formed to surround the outer surface of the main body; Includes, The resin of the main body is semi-cured by heat treatment, and A wire for a fiber-reinforced plastic stranded cable, wherein the thermoplastic fiber layer is hardened by cooling after heat treatment so that the semi-cured resin of the main body does not pass through the thermoplastic fiber layer.

2. A wire for a fiber-reinforced plastic stranded cable, wherein the resin of claim 1 is a thermoplastic resin or a thermosetting resin.

3. A wire for a fiber-reinforced plastic stranded cable according to claim 1, wherein the resin is 15% to 35% by weight of the fiber bundle weight.

4. A wire for a fiber-reinforced plastic stranded cable according to claim 1, wherein the thickness of the thermoplastic fiber layer is 0.2 mm to 1.0 mm.

5. A plurality of wires comprising a main body including a fiber bundle impregnated with resin and a thermoplastic fiber layer formed to surround the outer surface of the main body are twisted together and then the resin is cured by heat treatment to form a structure, A stranded cable having a fiber-reinforced plastic stranded cable, wherein the resin of the main body is semi-cured by heat treatment, and the thermoplastic fiber layer is hardened by cooling after heat treatment so that the semi-cured resin of the main body does not pass through the thermoplastic fiber layer, and then a plurality of strands are stranded and the semi-cured resin is hardened by heat treatment.

6. A supply device for supplying fiber bundles; Impregnation device for impregnating resin into supplied fiber bundles; A fiber layer forming device for forming a thermoplastic fiber layer to surround the outer surface of a fiber bundle impregnated with resin; A curing device for semi-curing a resin impregnated in a fiber bundle by heat treatment; and A winding device for winding a wire formed by cooling after heat treatment to harden a thermoplastic fiber layer so that a semi-cured resin does not pass through the thermoplastic fiber layer; A manufacturing apparatus for wires for fiber-reinforced plastic stranded cables, comprising 7. An apparatus for manufacturing wires for fiber-reinforced plastic stranded cables, wherein the curing apparatus heat-treats at a temperature of 100°C to 150°C.

8. Supply step for supplying fiber bundles; Impregnation step of impregnating the supplied fiber bundles with resin; A fiber layer forming step of forming a thermoplastic fiber layer to surround the outer surface of a fiber bundle impregnated with resin; A curing step of semi-curing the resin impregnated in the fiber bundle by heat treatment; and A winding step of winding a wire formed by cooling after heat treatment to harden the thermoplastic fiber layer so that the semi-cured resin does not pass through the thermoplastic fiber layer; A method for manufacturing a wire for a fiber-reinforced plastic stranded cable, comprising:

9. A method for manufacturing a wire for a fiber-reinforced plastic stranded cable, wherein the curing step of claim 8 is heat-treated at a temperature of 100°C to 150°C.

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