JP2010027224A - Method for manufacturing carbon fiber heater wire, carbon fiber heater wire, and snow melting heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a carbon fiber heater wire having a uniform temperature distribution, quickly raising temperature, and generating high-temperature heat with small electric power, which are basic characteristics of a heating wire; to provide the carbon fiber heater wire; and to provide a snow melting heater. <P>SOLUTION: A method for manufacturing a carbon fiber heater wire comprises: a step of drawing out a carbon fiber bundle 6 from a bobbin 21; a step of coating epoxy oil 14 on a surface of the carbon fiber bundle which has been drawn out; a step of forming a coating film on the carbon fiber bundle on which the epoxy oil has been coated; and a step of cooling the carbon fiber bundle on which the coating film has been formed. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a carbon fiber heater wire manufacturing method, a carbon fiber heater wire, and a snow melting heater.

  In recent years, heaters using carbon fibers as heating elements have been developed and are being put into practical use. However, in the conventional heating element, in order to increase the resistance value of the heating element, the carbon fiber is thinned or the amount of the carbon fiber is reduced. In this case, there is a problem that each fiber is broken or disconnection occurs.

  In order to solve such a problem, for example, Patent Document 1 discloses an invention related to a carbon-based heating element in which carbon fibers are not scattered, a heater using the carbon-based heating element, and a heating device including the heater. .

  The outline of this conventional heater will be described with reference to FIG. The heater is formed by enclosing a heating element 51, a heat dissipation block 52 and an internal lead wire 53 in a glass tube 50.

  The glass tube 50 is an amorphous glass of transparent quartz glass (for example, # 214 manufactured by GE or Vycor glass manufactured by Dow Corning (product number # 7190)). The diameter of the glass tube is set to such a size that the heating element 51 does not hit even if it vibrates. In an embodiment, the size of the glass tube is 10.5 mm in diameter.

  The heating element 51 is formed by plain weaving a plurality of warp yarns 51a which are carbon fibers extending in the longitudinal direction and a single weft yarn 51b extending in the width direction. A method for manufacturing the heating element will be described.

  One weft 51b is woven so that the top and bottom of the plurality of warps 51a are crossed in order (weaving step). The weft yarn 51b is folded at both ends in the width direction of the plurality of warp yarns 51a. The resin is thinly and evenly attached to the woven warp and weft (attachment step). The woven product (heat generating part) is fired to integrate the whole (firing step). By heating, the heating element is carbonized. The carbon-based heating element of the embodiment is formed of only a plurality of yarns that are continuous between the ends in the longitudinal direction.

  The above-mentioned conventional heater has an advantageous effect that a carbon-based heating element in which carbon fibers are not scattered can be realized by weaving so that the weft yarn has at least one turn and the upper and lower sides of the warp yarn are crossed. It is done. However, this heater needs to interweave the warp and weft of carbon fiber, and its production cost is not necessarily low.

  Therefore, another heater manufacturing method using PAN (polyacrylonitrile) -based carbon fiber has been proposed.

As this manufacturing method, a carbon fiber is drawn out from a bobbin, passed through a guide, and then silicon rubber or vinyl chloride is covered with an electric wire processing extrusion molding machine to form a heater.
JP 2008-53247 A

  With the heater manufacturing method described above, it becomes possible to manufacture a long heater continuously at a lower cost than the manufacturing method disclosed in Patent Document 1.

  However, since the PAN-based carbon fiber is thin and has a small elongation at break, the PAN-based carbon fiber may be damaged or become fluffy depending on the handling, and the shortened single fiber is likely to fly or dust and be easily scattered in the atmosphere. Also, when pulling out continuous carbon fiber from the bobbin, rubbing with a guide creates fluff that breaks into a fly. Moreover, since carbon fiber has electrical conductivity, fly and lint have also caused a short circuit in the electrical system. FIG. 6 shows an external view of a conventional carbon fiber heater wire.

  In the conventional manufacturing method, a film is applied with silicon or vinyl chloride without considering the above-mentioned precautions for carbon fiber. Such a heating wire coated with vinyl chloride has two problems.

  One is that the monofilament breaks through the film, resulting in poor insulation. The other is that when the single fiber is drawn into the die, the rubbing machine stops at the guide. As a result, although it does not appear in the resistance value, a thick portion and a thin portion are formed, and a temperature difference can be made when a heat generation test is performed.

  The manufacturing method of the carbon fiber heater wire according to the prior art applies the film without twisting, so the problem that is not known in the resistance measurement test, the leakage problem that does not come out unless using a conductive adhesive such as asphalt emulsion, etc. It was the present situation that was out.

  The present invention has been made in view of the above points, and its purpose is to produce a carbon fiber heater wire that has a uniform temperature distribution, which is the basis of the heating wire, has a fast temperature rise, and generates high-temperature heat with low power. It is an object to provide a method, a carbon fiber heater wire and a snow melting heater.

  In order to achieve the above-mentioned object, the present invention comprises the following configurations (1) to (4).

  (1) A step of drawing the carbon fiber bundle from the bobbin, a step of applying epoxy oil to the surface of the drawn carbon fiber bundle, and a step of forming a film on the carbon fiber bundle to which the epoxy oil is applied A method for producing a carbon fiber heater wire, comprising the step of cooling the carbon fiber bundle on which the film is formed.

  (2) The method for producing a carbon fiber heater wire according to (1), wherein the epoxy oil is an oil having conductivity and nonflammability.

  (3) A carbon fiber heater wire produced by the production method according to (1) or (2).

  (4) A plurality of metal pipes, a power supply line installed at the center of the pipe and covered with a glass tube, and a plurality of pipes installed at a predetermined interval between the inner wall of the metal pipe and the glass tube A heater for melting snow, comprising the carbon fiber heater wire according to claim 1.

  By having the above-described configuration, the present invention can provide a carbon fiber heater wire manufacturing method, a carbon fiber heater wire, and a snow melting heater that have a uniform temperature distribution and generate heat with low power.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to examples.

  First, the manufacturing method of a carbon fiber heater wire is demonstrated, referring FIG. 1 and FIG.

  An outline of the manufacturing process is shown in FIG. First, the carbon fiber bundle is pulled out from the bobbin 21 around which the carbon fiber bundle 6 as the raw material is wound. In this embodiment, PAN-based carbon fiber is used. One PAN-based carbon fiber is as thin as 7 microns. Two types of 12K, which is a collection of 12,000, and 24K, which is a collection of 24,000, are mainly manufactured. For example, it is assumed that three twisted carbon fibers are wound around a bobbin, and this is pulled out from the bobbin.

  The drawn bundle of carbon fibers is inserted into a jig. In this case, the introduction port has a smooth introduction shape (for example, funnel shape) so that the carbon fiber is not caught by the jig as much as possible.

  Next, epoxy oil is applied to the surface of the bundle of carbon fibers introduced into the jig. This application is performed immediately after the bundle of carbon fibers is introduced into the jig. In the figure, 14 is an epoxy oil, 4 is an oil container, 5 is a pump, 15 is a pressure regulating valve, and 16 is a hose. Thus, by applying the epoxy oil, it is possible to prevent the carbon fibers from falling apart, and when the coating is subsequently coated, the carbon fiber fluff is prevented from penetrating through the coating. be able to. The carbon fiber bundle may be twisted before applying the epoxy oil. Moreover, although the epoxy oil was used in the present Example, other oil may be used if it is other nonflammable oil with electroconductivity and desired viscosity. The epoxy oil here refers to an emulsion type epoxy.

  The carbon fiber coated with epoxy oil is introduced into the die 1. In this die, a coating is placed on the outer periphery of the carbon fiber bundle. The film material 13 is stored in the film material popper 3, heated by the heater 12, and then extruded to the die side by the screw conveyor 12. The extruded film material covers the outer periphery of the carbon fiber bundle in the die to form a carbon fiber heater wire. By forming the carbon fiber heater wire in this way, it is possible to obtain a heater wire in which no carbon fiber enters the coating.

  As shown in FIG. 1, the carbon fiber heater wires are sequentially cooled by the cooling water in the water tank 7 while being supported by the guide 8, and are taken up by the winder 9.

  As described above, the carbon fiber heater wire manufacturing method of the present embodiment is composed of very simple processes and is suitable for high-speed continuous manufacturing of heater wires.

  FIG. 3 and FIG. 4 show the temperature test results of the carbon fiber heater wire produced by the above-described method and the carbon fiber heater wire not coated with the conventional epoxy oil, respectively. The carbon fiber heater used in this test was a carbon fiber having a length of 1 meter and twisted 3 pieces of 12K. From this test result, it can be seen that there is a great improvement especially at 1.8A. This is thought to be because the coating was applied in a state where the carbon fibers were bundled together well without causing fluff or the like. Also, the temperature distribution in the axial direction of the heater was almost uniform.

  In this example, a snow melting heater using the carbon fiber heater wire produced by the production method of Example 1 will be described.

  The carbon fiber of this heater is very vulnerable to disturbances (changes in temperature) when the temperature is kept constant by automatic control. For example, even if this carbon fiber heater wire is placed in ice or snow as it is, the effect of heat generation is little. Absent. To protect against external disturbances, even when they are placed in a conduit or embedded in asphalt, half of the heating wire is covered with rubber to transfer heat to the asphalt surface and protect it from external disturbances.

  The snow melting heater of this example will be described with reference to FIGS. The basic structure of this heater is shown in FIG. FIG. 5A is an external view, and FIG. 5B is a cross-sectional view.

  In the center, two power supply wires 19 housed in a glass tube 18 are installed, and three carbon fiber heater wires 17 are arranged on the outside of the glass tube, and these are made of metal. It is assumed that it is covered with a metal pipe 20 that is a wiring pipe. Although not shown, a required number of terminal boards are arranged in the axial direction of the snow melting heater, and electric power is supplied from the feeder to the carbon fiber heater wires via the terminal boards. This metal pipe has a function of protecting the carbon fiber heater wire from an external temperature change. In addition, when installing a long carbon fiber heater, this carbon fiber shall be divided | segmented into predetermined length, and it shall have the structure which electrically feeds each carbon fiber from a feeder via a terminal board. By doing so, stable heat generation is possible.

  FIG. 6 shows an installation example of the snow melting heater wire 30 of the present embodiment on the ground surface. As shown in the figure, when it is desired to melt snow within a predetermined range of the ground surface, the heater wire is bent and used. In this case, R shown in the figure should be 200 mm or more. This is because if this R is small, the carbon fiber itself may be broken. Carbon fiber is inherently brittle, and distortion occurs when it is bent with a small radius. When electricity is applied in this state, a location where heat generation is concentrated occurs, and as a result, a phenomenon such as disconnection occurs. In the figure, reference numeral 40 denotes a power supply box.

  The above-mentioned snow melting heater has a function of melting snow stably with low power as compared with a conventional heater.

The perspective view which shows the whole manufacturing process of the carbon fiber heater wire of Example 1. The figure which shows the detail of the oil application process of the manufacturing process of the carbon fiber heater wire of Example 1, and a film formation process The figure which shows the temperature test result of the carbon fiber heater wire of Example 1 The figure which shows the temperature test result of the conventional carbon fiber heater wire The figure which shows the structure of the heater for snow melting of Example 2. The figure which shows the example of installation of the heater for snow melting of Example 2. The figure which shows the example of the conventional carbon fiber heater wire The figure which shows the other example of the conventional carbon fiber heater wire

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Dice 2 Jig 3 Coating material hopper 4 Oil container 5 Pump 6 Carbon fiber bundle 7 Water tank 8 Guide 9 Winder 10 Motor 11 Screw conveyor 12 Heater 13 Molten coating material 14 Epoxy oil 15 Pressure adjustment valve 16 Hose 17 Carbon fiber Heater wire 18 Glass tube 19 Power supply line 20 Metal pipe 21 Bobbin 30 Snow melting heater 40 Power supply box 50 Glass tube 51 Heating element 51a Warp yarn 51b Weft yarn 52 Heat radiation block 53 Internal lead wire 60 Conventional carbon fiber heater wire 61 Fluff

Claims (4)

Extracting the carbon fiber bundle from the bobbin;
Applying epoxy oil to the surface of the drawn carbon fiber bundle;
Forming a film on the carbon fiber bundle to which the epoxy oil is applied; and
A method for producing a carbon fiber heater wire, comprising a step of cooling a carbon fiber bundle on which the film is formed.   The method for producing a carbon fiber heater wire according to claim 1, wherein the epoxy oil is an oil having conductivity and nonflammability.   A carbon fiber heater wire produced by the production method according to claim 1 or 2. Metal pipes,
A power supply line installed at the center of the pipe and covered with a glass tube;
3. A snow melting heater comprising a plurality of carbon fiber heater wires according to claim 1 or 2 installed at a predetermined interval between an inner wall of the metal pipe and the glass tube.

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