Manufacturing method of reinforcing bar and impregnation device used therein

Abstract

This invention provides an impregnating apparatus used in a method for manufacturing a reinforcing bar that fully impregnates and integrates a thermoplastic resin material within a reinforcing fiber material to achieve sufficient strength. In this invention, multiple guide plates 4A to 4C are arranged along the passage direction of the reinforcing fiber material Fb within the space of a box-shaped impregnating apparatus 1 containing thermoplastic resin. The reinforcing fiber material Fb is guided outwards through through holes 41 in guide plates 4A and 4C, and guided inwards through through holes 42 in guide plate 4B located between guide plates 4A and 4C.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing reinforcing bars suitable for use in concrete reinforcement, etc., and to an impregnating device used therein. Background Technology

[0002] As a type of reinforcing bar, basalt fiber reinforcing bars, which replace existing iron reinforcing bars, have attracted attention for their ability to maintain the strength of concrete over a long period of time without rusting. For example, as shown in Patent Document 1, a reinforcing bar with a structure using basalt fiber bundles as the core material and surrounding it with a thermoplastic resin layer of a specified thickness has been proposed. Furthermore, conventional methods for forming the resin layer around the core material, as shown in Patent Document 1, have mostly employed impregnation methods, such as passing the core material through a molten resin solution or emulsion.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-251378 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] However, when using the impregnation method, there is a problem that if the thermoplastic resin material does not sufficiently impregnate the basalt fibers used as reinforcing fibers, it is impossible to obtain steel bars with sufficient strength.

[0008] Therefore, the present invention addresses the problem of providing a method for manufacturing a reinforcing bar that fully impregnates and integrates a thermoplastic resin material into and with a reinforcing fiber material, thereby achieving sufficient strength, and an impregnating apparatus used therein.

[0009] means for solving problems

[0010] To achieve the above objectives, the present invention relates to a method for manufacturing a steel bar, characterized in that it is a method for manufacturing a steel bar formed by impregnating and integrally forming a thermoplastic resin material within a reinforcing fiber material, wherein multiple reinforcing fibers are passed through a storage tank containing liquid thermoplastic resin material, and the following steps are repeated at least once: causing the reinforcing fibers to spread outward and converge inward in their passing direction.

[0011] According to the manufacturing method of the present invention, by repeating the following steps at least once, it is possible to promote the impregnation and full inclusion of thermoplastic resin in the reinforcing fibers to obtain a steel bar with sufficient strength that integrates the reinforcing fibers and the thermoplastic resin. The steps are to cause the reinforcing fibers in the liquid thermoplastic resin material to diffuse outward and converge inward in their passing direction.

[0012] In this second invention, a bulky processing is performed before the aforementioned reinforcing fiber material passes through the accumulation tank.

[0013] In this second invention, thermoplastic resin can be more efficiently impregnated into the fluffy reinforced fiber material.

[0014] In this third invention, the aforementioned accumulation tank is formed by a box-shaped impregnator (1), and a plurality of guide members (4A, 4B) are provided in the space of the impregnator (1) along the passing direction of the reinforcing fiber material (Fb). The reinforcing fiber material (Fb) is guided to an outward position by one of the aforementioned guide members (4A), and the reinforcing fiber material (Fb) is guided to an inward position by the adjacent other aforementioned guide members (4B).

[0015] The manufacturing method of the first invention can be easily implemented by using the impregnating apparatus of the third invention.

[0016] In this fourth invention, in one of the guide members (4A), a through hole (41) is formed on the outer side to allow the reinforcing fiber material (Fb) to pass through, and in the other guide members (4B), a through hole (42) is formed on the inner side to allow the reinforcing fiber material (Fb) to pass through.

[0017] According to this fourth invention, reinforcing fibers can be easily guided in the inward and outward directions through through-holes.

[0018] The symbols in parentheses above are shown for reference to correspond with the specific mechanisms described in the embodiments described later.

[0019] Invention Effects

[0020] As described above, according to the present invention, thermoplastic resin material can be fully impregnated within and integrated with reinforcing fibers to obtain a steel bar with sufficient strength. Attached Figure Description

[0021] Figure 1 This is a diagram showing the overall configuration of the apparatus used to implement the method of the present invention.

[0022] Figure 2 This is an exploded perspective view of the impregnator in the first embodiment of the present invention.

[0023] Figure 3 It is a perspective 3D view of the molding die.

[0024] Figure 4 This is a perspective 3D view of the impregnator.

[0025] Figure 5 This is an exploded perspective view of the impregnator in the second embodiment of the present invention.

[0026] Figure 6 It is a 3D diagram of the guiding components.

[0027] Figure 7 This is a perspective 3D view of the impregnator.

[0028] Symbol Explanation

[0029] 1… Impregnator, 3… Connecting metal parts, 4A, 4B, 4C… Guide plates (guide components), 41, 42… Through holes, 5… Molding mold, 7… Guide body, 72, 73, 74, 75… Guide components, 722, 733, 742, 754… Through holes, Fb… Basalt fiber (reinforcing fiber material), Rt… Polypropylene resin (thermoplastic resin material). Detailed Implementation

[0030] Furthermore, the embodiments described below are merely examples, and various design modifications made by those skilled in the art without departing from the spirit of the invention are also included within the scope of the invention.

[0031] Figure 1 The overall configuration of the apparatus for implementing the method for manufacturing steel bar bodies according to the present invention, including the impregnating device 1, is shown. Figure 1 The extruder 2 is equipped with a known structure, and polypropylene (PP) resin Rt, a thermoplastic resin material, is supplied into the extruder 2 from a feed hopper 21 provided on the upper surface of one end. The PP resin Rt is heated to a specified temperature and becomes molten in the extruder 2, and is then supplied to an impregnator 1 connected to the other end of the extruder 2 via an internal screw. Details of the impregnator 1 will be described below.

[0032] The detailed structure of impregnator 1 is shown below. Figure 2 The impregnator 1 has a main body 11 that is a square box shape that opens upwards, with one end wall 12 fixed to the other end 22 of the extruder 2. Figure 1The connecting metal part 3 is composed of a cylindrical base 31 and a large-diameter flange 32 formed at one end. A through hole 311 is formed in the center of the base 31, through which PP resin Rt output from the extruder 2 flows. The connecting metal part 3 is connected to the end wall 12 of the main body 11 by inserting bolts into mounting holes 312 formed on the outer periphery of the flange 32, and to the extruder 2 by inserting bolts into mounting holes 313 formed in the cylinder wall from the inner periphery of the flange 32.

[0033] On the end wall 12 of the main body 11, a plurality of small-diameter through holes 121 are formed in a circular area, which communicate with the inside of the cylinder of the connecting metal part 3 (see reference). Figure 5 The PP resin Rt output from the extruder 2 flows into the body 11 and accumulates in the body 11 after being rectified through these through holes 121.

[0034] Multiple (three in this embodiment) guide grooves 141 and 151 are formed opposite to each other on the side walls 14 and 15 opposite to the main body 11 of the impregnator 1. The guide grooves 141 and 151 extend vertically from the end wall 12 side toward the end wall 13 side at intervals to the bottom wall. Guide plates 4A, 4B, and 4C are installed by inserting them into these guide grooves 141 and 151 from above. These guide plates 4A to 4C are impregnated in PP resin Rt supplied from the extruder 2 and accumulated in the impregnator 1.

[0035] A cylindrical molding die 5 is fixed to the end wall 13 of the main body 11 of the impregnator 1. The details of the molding die 5 are shown in perspective view. Figure 3 In the forming mold 5, a through hole 51 for forming is formed in the center. The diameter of the through hole 51 gradually decreases from the base end side, and the front end side becomes equal to the outer diameter of the steel bar body, which is the final product. Regarding the forming mold 5, bolts are inserted into a plurality of (four in this embodiment) through-holes 52 around the through hole 51 to connect it to the end wall 13 of the impregnating vessel 1. When fixed to the end wall 13 of the impregnating vessel 1, the through hole 51 of the forming mold 5 and the through hole 131 formed in the end wall 13 (… Figure 2 Connect.

[0036] In addition, multiple transverse holes 16, which open to the side and are closed at one end, are formed on the bottom wall of the main body 11 of the impregnator 1. Figure 2 A rod-shaped heater is inserted into these transverse holes 16 to maintain the PP resin Rt at a specified temperature.

[0037] Figure 4 The diagram shows details of the guide plates 4A to 4C disposed within the main body 11 of the impregnator 1. These plates are installed in the guide grooves 141 and 151. Figure 2 In the guide plates 4A to 4C, the two guide plates 4A and 4C located near the end walls 11 and 12 are of the same shape, and small-diameter through holes 41 are formed at each corner of the square area As on the surface of the plate. Moreover, on the guide plate 4B located between the two guide plates 4A and 4C, a large-diameter through hole 42 is formed at a position corresponding to the center of the square area.

[0038] exist Figure 2 In this impregnator 1, two cover plates 17 and 18, one elongated and the other square, are laid together on the box-shaped main body 11 from top to bottom. Furthermore, fiber passage holes 172 are formed at equal intervals (four in this embodiment) on the cover plate 17 along its length direction, i.e., along the width direction of the impregnator. Moreover, the cover plates 17 and 18 are fixed to the upper surfaces of the end walls 12 and 13 and the side walls 14 and 15 of the box-shaped main body 11 of the impregnator 1 by bolts inserted into the mounting holes 171 and 181 provided in the cover plates 17 and 18.

[0039] In the case of manufacturing steel bar bodies, such as Figure 1 As shown, basalt fiber bundles Fb, which are extracted from coils 61 as reinforcing fiber material, are supplied to impregnator 1, pass through cooling water in cooling device 64 located at the rear of impregnator 1, and then are clamped from the top and bottom by mounting belt 65 at the rear. Furthermore, an example of the thickness of the basalt fiber bundles Fb is 4800 TEX.

[0040] That is, the basalt fiber bundles Fb drawn from each coil 61 pass through fluffing nozzles 62 midway, and are fluffed by air supplied to the fluffing nozzles 62. The fluffed basalt fiber bundles Fb pass through the cover plate 17 of the impregnator 1 via the tension roller 63. Figure 2 Each fiber passes through hole 172. (e.g.) Figure 4 As shown, each basalt fiber bundle Fb passing through the fiber through-hole 172 diffuses outward by passing through the through-holes 41 at each corner of the square region As formed in the guide plate 4A, which is impregnated with PP resin Rt supplied to and accumulated in the main body 11. Then, it converges inward by passing through the through-holes 42 formed in the guide plate 4B at the position corresponding to the center of the square region As. Furthermore, it diffuses outward by passing through the through-holes 41 at each corner of the square region As formed in the guide plate 4C, and then converges inward by passing through the through-holes 131 in the end wall 13 of the main body 11 at the position corresponding to the center of the square region As.

[0041] In this embodiment, during the passage of the basalt fiber bundle Fb through the PP resin Rt, the process of spreading outward and converging inward in its passing direction is repeated twice, thereby ensuring that the PP resin Rt is fully impregnated within the basalt fiber bundle Fb. Furthermore, the through-hole 51, which connects to the molding die 5 via the through-hole 131, is also present. Figure 3 Here, its diameter is gradually reduced to the outer diameter of the steel bar body, which is the final product. Then, as described above, it is cooled by a cooling device 64 ( Figure 1 The basalt fiber Fb is cooled to firmly integrate with the PP resin Rt fully impregnated therein, thus obtaining a steel bar with sufficient strength.

[0042] Furthermore, the through holes 41 of the guide plates 4A and 4C do not necessarily have to be formed at the corners of the square region As, and the through holes 42 of the guide plate 4B do not necessarily have to be formed at the position corresponding to the center of the square region As.

[0043] (Second Implementation)

[0044] Figure 5 The image shows an impregnator 1 according to a second embodiment of the present invention. The main body 11 of the impregnator 1 is box-shaped, similar to that of the first embodiment. A connecting metal member 3, which is attached to one end of the main body 11, also has a plurality of small-diameter through holes 314 formed in its central circular region; otherwise, it is the same as in the first embodiment. These through holes 314 communicate with a plurality of through holes 121 formed in the end wall 12 of the main body 11 of the impregnator 1, respectively, from the extruder 2 (… Figure 1 The PP resin Rt output flows into the body 11 after being rectified through these through holes 314 and 121. Furthermore, the structure of the molding die 5, which is coupled to the end wall 13 of the body 11 of the impregnator 1, and the cover plates 17 and 18 covering the body 11, are also the same as in the first embodiment. Therefore, the same symbols are used for the components that are the same as in the first embodiment.

[0045] In this embodiment, a guide 7 is provided inside the main body 11 of the impregnator 1. Details of the guide 7 are shown below. Figure 6 The guide body 7 has a long base 71 fixed to the bottom wall of the main body 11 of the impregnator 1, such as... Figure 5 As shown, the base 71 is provided from the end wall 12 side of the main body 11 to the end wall 13 side. On the base 71, guide members 72, 73, 74, and 75 are erected vertically in sequence at predetermined intervals along the length direction, starting from the position near the end wall 12.

[0046] Guide members 72 and 74 are identical in shape and are integrally formed in a ring. Small-diameter through holes 722 and 742 are formed at multiple intervals (five in this embodiment) along the circumferential direction within the ring portions 721 and 741. Furthermore, guide member 73 has a ring portion 732 with a large-diameter through hole 733 at its center formed on a plate-shaped support portion 731. Guide member 75 has an annular retaining portion 752 formed on a wall-shaped support portion 751, within which a cylindrical body 753 with a through hole 754 of a predetermined diameter is detachably held. Moreover, the centers of the ring portions 721 and 741 of guide members 72 and 74 and the centers of each through hole 733 and 754 of guide members 73 and 75 are located on the same line.

[0047] When manufacturing steel bars, such as Figure 7 As shown, the fiber passes through the cover plate 17 through the hole 172 ( Figure 5 Each basalt fiber bundle Fb passes through the through-hole 722 of the ring portion 721 of the guide member 72 impregnated in PP resin Rt, thus spreading outwards. Then, it passes through the through-hole 733 of the guide member 73, thus converging inwards. Next, it further passes through the through-hole 742 of the ring portion 741 of the guide member 74, thus spreading outwards, and then passes through the through-hole 754 of the guide member 75. Figure 6 This results in a state where it converges inwards. Furthermore, in Figure 7 In order to make it easier to understand, the position of the guide body 7 and the through hole 131 of the corresponding main body end wall 13 is drawn closer to the top than it actually is.

[0048] Thus, in this embodiment, the process of spreading outward and converging inward in the direction of basalt fiber bundle Fb is repeated twice during its passage through PP resin Rt, ensuring that the PP resin Rt is fully impregnated within the basalt fiber Fb. Then, it reaches the through-hole 51 of the molding die 5 communicating with it through the through-hole 131 of the main body end wall 13. Figure 5 The diameter is gradually reduced to the outer diameter of the steel bar body, which is the final product. During this process, the basalt fiber Fb is integrated with the PP resin Rt fully impregnated therein, and then cooled by device 64. Figure 1 The steel bar is cooled to achieve sufficient strength. Here, an example of the diameter of the steel bar is about 5 mm, and the tensile strength of the steel bar is about 15 kN.

[0049] Furthermore, the centers of the ring portions 721 and 741 of the guide members 72 and 74 and the centers of the through holes 733 and 754 of the guide members 73 and 75 do not necessarily have to be on the same line.

[0050] In the above embodiments, the diffusion of basalt fibers to the outer position and the contraction to the inner position are repeated twice, but this can be carried out once to three times or more, corresponding to the impregnation state of PP resin into the basalt fibers.

[0051] In the above embodiments, basalt fibers are fed to the impregnator after being split, but this is not a necessary process.

[0052] In the above embodiments, basalt fibers are guided to the outer to inner positions through through holes, but guidance can also be performed using structures other than through holes.

[0053] In addition to PP resin, polyethylene resin, nylon resin, polyester resin, etc., can be used as the thermoplastic resin material in the above embodiments. Furthermore, in addition to basalt fiber, inorganic fibers such as glass fiber and carbon fiber, and organic fibers such as aramid fiber and acrylic fiber can be used as the reinforcing fiber.

Claims

1. A method of manufacturing a steel bar body, characterized by, A method for manufacturing a reinforcing bar body in which a thermoplastic resin material is impregnated and integrated within a reinforcing fiber material, in which a plurality of reinforcing fiber materials are passed through an accumulation tank in which a liquid thermoplastic resin material is accumulated, a plurality of guide members are provided along a passing direction of the reinforcing fiber materials, and the following process is repeated at least once: the reinforcing fiber materials are respectively passed through a plurality of through-holes formed in one of the guide members in the passing direction thereof, spread to a radially outer position, and passed through a through-hole formed in an adjacent other guide member, gathered to a radially central position, and further gradually reduced in diameter to an outer diameter of the reinforcing bar body as a final product in a molding die provided along the passing direction of the reinforcing fiber materials, and a through-hole formed in an adjacent other guide member is formed at a position corresponding to a center of a region constituted by the plurality of through-holes formed in one of the guide members, the plurality of outer positions are set to the same distance radially outward from the central position over the entire region of the passing travel of the reinforcing fiber materials, and fluffing processing is performed before the reinforcing fiber materials are passed through the accumulation tank.

2. An impregnator for use in the manufacturing method of the steel bar body as claimed in claim 1, wherein, The accumulation tank is constituted by a box-shaped impregnator, a fiber passing hole through which the reinforcing fiber materials passed before fluffing processing is performed is provided on a cover plate of the impregnator, a plurality of guide members are provided in the space of the impregnator along the passing direction of the reinforcing fiber materials, one of the guide members in which a plurality of through-holes are formed guides the reinforcing fiber materials to the outer position, a through-hole formed in an adjacent other guide member is formed at a position corresponding to a center of a region constituted by the plurality of through-holes formed in one of the guide members, the adjacent other guide member in which a through-hole is formed guides the reinforcing fiber materials to the central position, and the plurality of outer positions are set to the same distance radially outward from the central position over the entire region of the passing travel of the reinforcing fiber materials, and a molding die in which a molding through-hole is formed which is gradually reduced in diameter from a base end side and the outer diameter of the reinforcing bar body as a final product becomes equal to the front end side is provided on an end wall of the impregnator.

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