JP2010279853A - Apparatus and method of manufacturing solid lubricant coated metal sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and method of manufacturing a solid lubricant coated metallic plate in which the clogging of a coating nozzle caused by the solidification of a solid lubricant is fully eliminated to enhance a working efficiency, the distribution of the solid lubricant applied onto the metal sheet is uniformed to improve the quality of the solid lubricant coated metal sheet. <P>SOLUTION: The manufacturing apparatus for manufacturing the solid lubricant coated metal sheet by an electrostatic coating method includes: a coating nozzle 2 having a head 5 composed of an electrical insulating medium, an ejecting path 6 formed in the head 5 to eject the solid lubricant L, a lubricant supply pipe 7 communicating with the ejecting path 6 to supply the solid lubricant L and composed of the electrical insulating medium, and an electrode 8 impressing negative charge to the solid lubricant L in the ejecting path 6; a lubricant supply path 3 communicating with the lubricant supply pipe 7 to supply the solid lubricant L; and a heater 4 arranged between the coating nozzle 2 and a metal sheet 10 to be in parallel to the coating nozzle 2, and also arranged provided in a position where the short circuit with the coating nozzle 2 due to the discharge does not occur. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a manufacturing apparatus and a manufacturing method for manufacturing a solid lubricant-coated metal plate coated with a solid lubricant, and in particular, a manufacturing apparatus for coating a metal plate with a solid lubricant by an electrostatic coating method. And a manufacturing method.

  Solid lubricant coated metal plates are made by coating one or both surfaces of a metal plate such as a hot-rolled steel plate or a cold-rolled steel plate with a solid lubricant at room temperature. The metal plate has excellent press formability (lubricity). It has been granted.

  In general, press working of metal plates is used in a very wide range of fields, from industrial products such as automobiles, home appliances, and office equipment to manufacturing daily necessaries such as beverage cans, sinks, and bathtubs. It occupies an important position. Normally, when press working is performed, press oil (lubricating oil) is applied to improve moldability (lubricity and workability) in order to prevent scratches on the mold and metal plate surface due to poor lubrication. Has been done.

  However, in recent years, for example, in order to meet the needs for reducing the weight of automobiles, it is difficult to press compared to hot-rolled steel sheets, cold-rolled steel sheets, etc. Examples of applying aluminum plates, aluminum alloy plates, titanium plates, copper plates, and the like are increasing, and the need for improving the formability of such difficult-to-process materials is increasing.

  Therefore, a method is known in which a solid lubricant coating layer excellent in lubricity that can be expected to have excellent formability is previously formed on the surface of a metal plate. In this case, a material manufacturer that is a metal plate supplier supplies a coating layer after forming a coating layer on the surface of the metal plate in advance (so-called precoat). Solid lubricant is present at the interface between the workpiece and the mold during plastic processing, and plays a role in improving the formability by reducing its friction coefficient and preventing seizure. Compared to oil, etc., it is present and remains at the machining interface even under severer machining conditions and continues to exhibit a lubricating function. However, since this solid lubricant is literally solid at room temperature, there is a problem that when it is applied to a metal plate, it cannot be handled like conventional liquid oil.

  As a method of applying a solid lubricant to a metal plate, for example, after preparing a coating solution in which the solid lubricant is dissolved in a solvent, apply the spray to the metal plate with a spray coater or roll coater, and then heat to remove the solvent and cool it. A method (coating method) for obtaining a solid lubricant-coated metal plate is known. In this painting method, it is necessary to heat the metal plate to remove the solvent, and the installation of the heating furnace requires not only a large site and high initial investment cost, but also increases the running cost for the operation. There has been a problem that the environmental load becomes large, such as a large amount of energy consumption and generation of VOC.

  As another method, there is a method (electrostatic coating method) in which a solid lubricant is heated and melted to be liquefied and applied to a metal plate by applying an electrostatic coating method in this state. According to this electrostatic coating method, the molten solid lubricant is cooled and solidified as soon as it comes into contact with the metal plate, thereby forming a solid lubricant coating layer. This eliminates the need for a heating furnace to remove the solvent, which was essential in the painting method. This reduces the installation space, initial investment, and running costs, as well as significantly reduces the energy used and the amount of VOC generated. There is an advantage that it can be reduced and the environmental load can be reduced.

  As described above, the electrostatic coating method has several advantages over the coating method in forming the solid lubricant coating layer on the metal plate. However, when applying the electrostatic coating method, it is necessary to heat and melt the solid lubricant and supply it in a liquid state. For this reason, it is necessary for the electrostatic coating apparatus for a solid lubricant to keep the solid lubricant ejection flow path such as the lubricant tank and the lubricant supply pipe at a temperature equal to or higher than the melting peak temperature.

  For example, as a method of maintaining the temperature of the solid lubricant, Patent Document 1 describes a method of heating the solid lubricant immediately before being ejected from the ejection head. Patent Document 2 discloses a method of heating the lubricant by covering the outside of the nozzle head (jet head) with a heat exchanger pipe, and heating the solid lubricant by introducing hot air into the nozzle head (jet head). How to do is described. Furthermore, Patent Document 3 describes a method of transporting oil mist (solid lubricant) charged with air heated by a heat exchanger into an electrostatic oil coating apparatus. And the method of preventing coagulation | solidification of a solid lubricant by providing a cover around the electrostatic oiling apparatus, sending hot air etc. in the inside, and keeping heat is also considered.

Japanese Utility Model Publication No. 05-76544 JP 2006-150217 A JP 2009-34594 A

  However, in the method described in Patent Document 1, it is relatively easy to maintain the temperature of the solid lubricant when the ejection amount (application amount to the metal plate) is large. The influence of heat dissipation when supplying the solid lubricant cannot be ignored, the temperature of the solid lubricant decreases, and the solid lubricant solidifies in the middle of the lubricant supply pipe in the ejection head. As a result, there is a problem that the lubricant supply pipe is blocked and the working efficiency is lowered.

  Further, the method described in Patent Document 2 has the following problems. In electrostatic coating, a high voltage is applied to the solid lubricant by an electrode in the nozzle head. Therefore, in the method of covering the nozzle head with the heat exchanger pipe, if the distance between the electrode and the heat exchanger pipe is close (less than 100 mm), a short circuit occurs between the electrode and the heat exchanger pipe, There is a problem that electrostatic atomization of the solid lubricant stops. Further, in the method of introducing hot air, the tip portion of the nozzle head is separated from the hot air introducing portion and exposed to the outside air, so that the temperature of the solid lubricant is likely to drop to a temperature below the melting peak temperature, and the solid lubricant Solidifies and accumulates at the tip of the nozzle head. As a result, the nozzle head is blocked and work efficiency is reduced.

  Furthermore, in the method described in Patent Document 3, since the air flow is remarkably generated, the influence of the air flow causes variation in the amount of applied solid lubricant. As a result, there is a problem that the distribution of the solid lubricant applied to the metal plate is not uniform, and the quality of the solid lubricant-coated metal plate is deteriorated.

  Therefore, the present invention was devised to solve such a problem, the purpose of which can wipe out the blockage of the coating nozzle due to the solidification of the solid lubricant, can improve the work efficiency, An object of the present invention is to provide an apparatus and a method for manufacturing a solid lubricant-coated metal plate that can make the distribution of the solid lubricant applied to the metal plate uniform and improve the quality of the solid lubricant-coated metal plate.

  In order to solve the above-mentioned problem, a solid lubricant-coated metal sheet manufacturing apparatus according to the present invention is a solid lubricant-coated metal sheet manufacturing apparatus that manufactures a solid lubricant-coated metal sheet by electrostatic coating, A head made of an electrical insulator installed at a position opposite to a metal plate having a positive charge to be conveyed, and the solid lubricant in a molten state formed inside the head and opened to the metal plate side An ejection flow path to be ejected; a lubricant supply pipe made of an electrical insulator that communicates with the ejection flow path and supplies the molten solid lubricant; and the molten solid lubrication supplied to the ejection flow path An application nozzle having an electrode for applying a negative charge to the agent, a lubricant supply channel that communicates with the lubricant supply pipe and supplies the solid lubricant that has been melted by the melting means, and the application Between the nozzle and the metal plate It provided in parallel with the fabric nozzles, and characterized in that it comprises a heater provided at a position where a short circuit due to the discharge does not occur between the coating nozzle.

  According to the above configuration, since the application nozzle is heated by providing the heater provided at a predetermined position, the lubricant is supplied to the lubricant supply pipe and the ejection flow path formed inside the head by the lubricant supply flow path. The temperature drop of the melted solid lubricant is suppressed. As a result, the solid lubricant is suppressed from solidifying in the lubricant supply pipe and in the ejection flow path. Moreover, since a short circuit due to discharge does not occur between the heater and the application nozzle, stable electrostatic application is possible. In addition, since hot air is not used as the heating means of the head as in the conventional manufacturing apparatus, the amount of solid lubricant applied does not vary due to the flow of air.

  The method for producing a solid lubricant-coated metal plate according to the present invention is a method for producing a solid lubricant-coated metal plate for producing a solid lubricant-coated metal plate by an electrostatic coating method. The above-described head and the lubricant supply pipe measured in accordance with JISK7201 and at least the melting peak temperature of the solid lubricant measured in accordance with JISK7121 at the coating nozzle with the heater. The solid lubricant coating layer is applied to the surface of the metal plate by ejecting the solid lubricant in a molten state from the coating nozzle toward the metal plate while heating to a temperature lower than the continuous use temperature of the electrical insulator constituting It is characterized by forming.

  According to the method, by using the manufacturing apparatus, a temperature drop of the molten solid lubricant supplied to the lubricant supply pipe and the ejection flow path by the lubricant supply flow path is suppressed. As a result, the solid lubricant is suppressed from solidifying in the lubricant supply pipe and in the ejection flow path. In addition, since a short circuit due to discharge does not occur between the heater and the application nozzle, there is little variation in the amount of solid lubricant applied, and stable electrostatic application can be performed. It should be noted that unlike the conventional manufacturing method, hot air is not used to heat the application nozzle, so that the amount of solid lubricant applied does not vary due to the flow of air. Further, when the molten solid lubricant is applied to the surface of the metal plate, the temperature of the molten solid lubricant is further suppressed by heating the application nozzle in a predetermined temperature range. Solidification of the lubricant is further suppressed.

  According to the manufacturing apparatus and the manufacturing method of the solid lubricant-coated metal plate according to the present invention, since solidification of the solid lubricant in the molten state is suppressed, the blockage of the coating nozzle can be eliminated, and the working efficiency can be improved. . Further, since the coating amount of the solid lubricant does not vary, the distribution of the solid lubricant applied to the metal plate becomes uniform, and the quality of the solid lubricant-coated metal plate can be improved.

It is a perspective view which shows the structure of the manufacturing apparatus of the solid lubricant covering metal plate which concerns on this invention. It is sectional drawing of the manufacturing apparatus of FIG. 1 which shows the outline of the manufacturing method of the solid lubricant covering metal plate which concerns on this invention.

The manufacturing apparatus and manufacturing method of the solid lubricant coated metal plate according to the present invention will be described.
The manufacturing apparatus and manufacturing method for a solid lubricant-coated metal plate are a manufacturing apparatus and a manufacturing method for manufacturing a solid lubricant-coated metal plate by an electrostatic coating method. Here, the electrostatic coating method is a coating method in which a solid lubricant is heated to a molten state, and the molten solid lubricant is applied to the surface of the metal plate using electrostatic action. A solid lubricant coating layer made of a solid lubricant is formed on the surface (one side or both sides).

The solid lubricant is a lubricant that is maintained in a solid state in a normal storage / use environment, and has a melting peak temperature defined by JIS K7121 of 40 ° C. or higher, that is, a molten state at 40 ° C. or higher. Say what.
There is no particular restriction on the chemical composition of the solid lubricant, but in the production equipment for the solid lubricant coated metal sheet by the electrostatic coating method, resin parts may be used as parts of the production equipment, and the heating temperature exceeds 120 ° C. In such a case, a high heat-resistant resin or ceramics must be used for the part, and therefore the melting peak temperature of the solid lubricant is preferably 120 ° C. or lower.

Furthermore, the electric resistance value when the solid lubricant is melted is preferably 30 MΩcm or more. When the electrical resistance value is less than 30 MΩcm, it is not preferable because it is difficult to form a solid lubricant coating layer on the surface of the metal plate by electrostatic coating. The preferable upper limit value of the electric resistance value depends on the material constituting the manufacturing apparatus for the solid lubricant-coated metal plate. That is, the electrical resistance value of the solid lubricant is a specific resistivity (for example, the coating nozzle 2 is made of a resin material such as polyacetal) of the high voltage application portion of the manufacturing apparatus (see the coating nozzle 2, see FIG. 1 and FIG. 2). If it exceeds 1 × 10 ¹⁰ Ωcm, it is not preferable because the dielectric breakdown of the device itself occurs and the coating cannot be performed.

  There are no particular restrictions on the metal plate to which the solid lubricant is electrostatically applied. Alloyed hot-dip galvanized steel plate, hot-rolled steel plate, cold-rolled steel plate, high-tensile steel plate, plated steel plate, stainless steel plate, aluminum plate used for automobile parts, etc. An aluminum alloy plate, a titanium plate, a copper plate and the like can be exemplified. However, the material of the metal plate is not limited to the above material as long as it is a metal plate to which a lubricant is applied in order to improve lubricity and workability during press working.

  Although the metal plate depends on the application of the product (solid lubricant-coated metal plate), a coil or plate having a plate thickness of 0.1 to 3.0 mm and a plate width of 100 to 2000 mm is usually used. And a metal plate is conveyed just under the manufacturing apparatus (coating nozzle) of the solid lubricant coating | coated metal plate mentioned later by conveyance means, such as a coil passage plate and a conveyor apparatus. In general, since the coil and the conveying means are grounded, the metal plate has a positive charge.

<Production device for solid lubricant coated metal plate (hereinafter referred to as production device)>
As shown in FIGS. 1 and 2, the manufacturing apparatus 1 includes an application nozzle 2, a lubricant supply channel 3, and a heater 4.

(Application nozzle)
The application nozzle 2 is for ejecting a molten solid lubricant L having a negative charge toward the transported metal plate 10 having a positive charge.
The application nozzle 2 has a head 5 installed at a position facing the metal plate 10, and is formed inside the head 5 and opens toward the metal plate 10 to direct the molten solid lubricant L to the metal plate 10. An ejection flow path 6 to be ejected, a lubricant supply pipe 7 which communicates with the ejection flow path 6 and supplies a molten solid lubricant L to the ejection flow path 6, and a molten state supplied to the ejection flow path 6 And an electrode 8 for applying a negative charge to the solid lubricant L. The lubricant supply pipe 7 and the electrode 8 are arranged on the side of the head 5 so as to communicate with the ejection flow path 6. In the drawing, the lubricant supply pipe 7 and the electrode 8 are disposed on the side portions facing each other, but may be disposed on the same side portion.

  In the head 5, electric charges are applied by the electrode 8 to the molten solid lubricant L supplied to the ejection flow path 6 formed in the head 5, so that a short circuit due to discharge does not occur between the head 5 and the electrode 5. It consists of electrical insulators. The electrical insulator is preferably a resin material, specifically a high heat resistance resin material called a so-called engineering plastic or super engineering plastic, more specifically a polyether ether ketone, Polytetrafluoroethylene, polyacetal and the like can be applied.

  The shape of the ejection channel 6 is not particularly limited as long as the molten solid lubricant L can be ejected toward the metal plate 10, and may be determined according to the melt viscosity of the solid lubricant L.

  The lubricant supply pipe 7 is held at a temperature equal to or higher than the melting peak temperature of the solid lubricant L by a heater. The shape is not particularly limited as long as the solid lubricant L in a molten state can be supplied to the ejection flow path 6, and the solid is calculated from the application amount of the solid lubricant L, the width of the metal plate 10, the conveyance speed, and the like. What is necessary is just to determine according to the supply amount of the lubricant L. Further, since the lubricant supply pipe 7 is close to the electrode 8 that applies a negative charge to the solid lubricant L, the lubricant supply pipe 7 is made of an electrical insulator so as not to cause a short circuit due to discharge. As the electrical insulator constituting the lubricant supply pipe 7, those exemplified as the electrical insulator constituting the head 5 can be applied, and it may be composed of the same type of electrical insulator as the head 5, or different types of electrical insulation. You may comprise. Furthermore, the lubricant supply pipe 7 may be branched into a plurality of pipes, for example, when the ejection flow path 6 is divided into a plurality of sections.

  The electrode 8 is connected to a power source (not shown), and the type of the electrode is not particularly limited as long as a negative charge can be applied to the molten solid lubricant L supplied to the ejection flow path 6. The voltage applied to the electrode 8 is preferably −50 to −80 kV, more preferably −60 to − in order to atomize the solid lubricant L as fine particles having a uniform particle size, as will be described later. -70 kV.

  The coating nozzle 2 includes a pair of head portions 5a and 5b facing each other, and a shim 9 made of a conductive material connected to the electrode 8 between the head portions 5a and 5b. 5b and the shim 9 may be fixed with a metal fixing screw 14 or the like, and the ejection flow path 6 may be formed by the head portions 5a and 5b and the shim 9. Further, although not shown, the ejection flow path 6 may be divided into a plurality of flow paths by providing the shim 9 with a plurality of grooves. By providing such a shim 9, it becomes easy to apply a negative charge to the solid lubricant L in a molten state.

  The length B of the application nozzle 2 (head 5) is preferably equal to or greater than the plate width of the metal plate 10. When the length B is less than the plate width of the metal plate 10, the solid lubricant coating layer 11 is hardly formed on the end portion in the width direction of the metal plate 10.

(Lubricant supply flow path)
The lubricant supply flow path 3 communicates with the lubricant supply pipe 7 and supplies the solid lubricant L melted by the melting means to the lubricant supply pipe 7. For example, rubber that is an electrical insulator or the like It consists of a pipe consisting of Note that the end of the lubricant supply channel 3 may be used as the lubricant supply pipe 7. The melting means heats the solid lubricant L to the melting peak temperature or higher to bring it into a molten state, and is, for example, an electric heater.

  Although not shown in the drawing, the lubricant supply channel 3 is a lubricant tank for storing the molten solid lubricant L, and a lubricant for feeding the molten solid lubricant L to the lubricant supply pipe 7. A pump and the like are provided. Further, the lubricant supply flow path 3 may be provided with a control valve for controlling the flow rate of the molten solid lubricant L and a relief valve for keeping the pressure constant, although not shown. Further, in order to prevent the temperature of the molten solid lubricant L from being lowered, electric heating is performed outside the lubricant supply flow path 3 (pipe) at a position 100 mm or more away from the coating nozzle 2 (head portion 5b). A heater or the like may be wound.

(Heating heater)
The heater 4 heats the lubricant supply pipe 7 in the vicinity of the coating nozzle 2 and the head portion 5b, and maintains the molten state of the solid lubricant L in the ejection flow path 6 and the lubricant supply pipe 7. Specifically, the temperature of the head 5 and the lubricant supply pipe 7 of the application nozzle 2 is maintained at a temperature equal to or higher than the melting peak temperature of the solid lubricant L, and is applied between the application nozzle 2 and the metal plate 10. It is provided in parallel with the length B direction of the nozzle 2 and is provided at a position where no short circuit occurs due to discharge with the coating nozzle 2. Further, the heater 4 is provided on one side (lubricant supply pipe 7 connection side) or both sides of the coating nozzle 2.

  The installation position of the heater 4, that is, the position where no short circuit due to discharge occurs between the coating nozzle 2 (such as the metal fixing screw 14 connected to the electrode 8 and the shim 9) is a distance D 1 of 100 mm or more. Some positions are preferred. When the installation position of the heater 4 is too close (when the distance D1 is less than 100 mm), there is a possibility that a short circuit occurs due to discharge between the electrode 8 or shim 9 to which a high voltage is applied during electrostatic application and the heater 4. Is unfavorable because of the high. The upper limit of the installation position of the heater 4 is not particularly defined, but the heating efficiency to the coating nozzle 2 (head 5 and lubricant supply pipe 7) decreases as D1 increases, so that a short circuit due to discharge does not occur. Of these, it is preferable to reduce D1.

  The specific installation position of the heater 4 is more preferably a position where the distance D1 from the coating nozzle 2 (head 5) is 150 mm or less. When the distance D1 exceeds 150 mm, the heating efficiency to the application nozzle (head 5 and lubricant supply pipe 7) tends to be lowered. That is, the heater 4 is at a position where a short circuit due to discharge does not occur, and the temperature of the coating nozzle 5 (head 5 and lubricant supply pipe 7) is equal to or higher than the melting peak temperature of the solid lubricant L measured according to JISK7121. And it arrange | positions in the position used as below the continuous use temperature of the electrical insulator which comprises the head 5 and the lubricant supply pipe | tube 7 which were measured based on JISK7201.

  The effective length A of the heater 4 is preferably at least equal to or longer than the length B of the application nozzle 2 (head 5). When the effective length A of the heater 4 is shorter than the length B of the application nozzle 2 (head 5), the heating efficiency at the end of the application nozzle 2 (head 5) is particularly lowered, which is not preferable. The heater 4 need not be one, and a plurality of heaters may be used in combination, and the total effective length A is equal to or greater than the length B of the application nozzle 2 (head 5). Just do it.

  The type of the heater 4 is not particularly limited, and any type can be used, but it is preferable to apply a rod-shaped infrared heater in consideration of economics such as price and heating (heat generation) efficiency. Further, it is preferable to provide a directivity by providing a reflector or a hood (not shown) around the heater 4 in a direction that does not require heating, in order to improve heating efficiency.

  Although not shown, the manufacturing apparatus 1 according to the present invention moves the coating nozzle 5 up and down with respect to the metal plate. Specifically, the distance D2 from the tip of the coating nozzle 5 to the surface of the metal plate 10 is set to 50 to 50. A vertical drive unit that changes within a range of 600 mm may be further provided. By providing the manufacturing apparatus 1 with the vertical drive unit, the film forming conditions can be adjusted according to the state of electrostatic atomization of the solid lubricant L.

<Method for producing solid lubricant-coated metal plate>
As shown in FIG. 2, the manufacturing method of the solid lubricant-coated metal plate 12 uses the manufacturing apparatus 1 and directs the coating nozzle 2 from the coating nozzle 2 toward the metal plate 10 while heating the coating nozzle 2 to a predetermined temperature. Then, the solid lubricant coating layer 11 is formed on the surface of the metal plate 10 by ejecting the solid lubricant L in a molten state.

  In the manufacturing method, since the application nozzle 2 is heated by the heater 4, the temperature of the head 5 (jet channel 6) and the lubricant supply pipe 7 is not lowered, and solid lubrication supplied from the lubricant supply channel 3. The molten state of the agent L is maintained. The molten solid lubricant L is ejected from the head 5 (ejection channel 6) toward the metal plate 10. At this time, since the solid lubricant L in the ejection flow path 6 is negatively charged by the electrode 8, it is atomized as fine particles having a uniform particle diameter by repulsion with the same polarity and sprayed toward the metal plate 10. The The sprayed solid lubricant L having a negative charge is bonded to the surface of the metal plate 10 having a positive charge by electrostatic action to form a solid lubricant coating layer 11, and the solid lubricant coating is formed. The metal plate 12 is manufactured.

Since the metal plate 10 is usually conveyed by a grounded conveyor device (not shown) or the like, it has a positive charge. Moreover, the conveyance speed of the metal plate 10 is determined by the thickness of the solid lubricant coating layer 11, and is usually 5 to 80 m / min. The thickness of the solid lubricant coating layer 11 is controlled by the amount of solid lubricant L attached, and is preferably 0.2 to 2.0 g / m ² per side of the metal plate 10. When the adhesion amount is less than 0.2 g / m ^2, it is not preferable because improvement in formability of the solid lubricant-coated metal plate 12 cannot be confirmed. On the other hand, if it exceeds 2.0 g / m ² , the cost will be increased, and the film removal property, weldability, and adhesiveness of the solid lubricant coated metal plate 12 will be deteriorated. Is not preferable because it cannot be expected.

  In the manufacturing method, the coating nozzle 2 is heated to a predetermined temperature by the heater 4. The temperatures of the coating nozzle 2, specifically, the head 5 and the lubricant supply pipe 7 are measured in accordance with the melting peak temperature of the solid lubricant L measured according to JISK7121 and according to JISK7201. Further, the temperature is not higher than the continuous use temperature of the electrical insulator constituting the coating nozzle 2 (the head 5 and the lubricant supply pipe 7). The melt viscosity is preferably 200 mPa · s or less.

  If the temperature of the coating nozzle 2 (the head 5 and the lubricant supply pipe 7) is lower than the melting peak temperature, solidification accompanying the temperature drop of the solid lubricant L occurs, and the coating nozzle 2 is blocked. When the temperature exceeds the continuous use temperature, the coating nozzle 2 (head 5 and lubricant supply pipe 7) is thermally deteriorated and needs to be replaced.

  The melting peak temperature may be measured using a commercially available differential scanning calorimeter under conditions of a sample weight of about 10 mg and a heating rate of 10 ° C./min. The melt viscosity may be measured using a commercially available rotational viscometer or the like while maintaining the solid lubricant L at a constant temperature equal to or higher than the melting peak temperature. The continuous use temperature is, for example, 250 ° C. when using polyetheretherketone as an electrical insulator, and 260 ° C. when using polytetrafluoroethylene. The electric resistance value (30 MΩcm or more) of the solid lubricant L was measured with an electrostatic tester E EMIV type (manufactured by Asahi Sunac) in a state where the solid lubricant L was heated to the melting peak temperature or higher and melted.

  The temperature measurement / control method of the application nozzle 2 (head 5 and lubricant supply pipe 7) is not particularly limited, but in order to prevent a short circuit due to discharge with the application nozzle 2, for example, non-contact such as a radiation thermometer. It is preferable to manage the temperature of the application nozzle 2 (the head 5 and the lubricant supply pipe 7) by applying a thermometer of the mold, or the temperature management of only the head 5 may be used. Based on this temperature data, it is preferable to control the temperature by applying a known technique such as manually or automatically adjusting the amount of power supplied to the heater 4.

Hereinafter, the present invention will be described more specifically with reference to examples.
(Example)
The manufacturing apparatus shown in FIGS. 1 and 2 was used, and electrostatic coating of a solid lubricant was performed on an aluminum plate (width 150 mm, length 200 mm).

As the solid lubricant, dry coat 2-90 (manufactured by Quaker Chemical Co., Ltd., melting peak temperature: about 48 ° C., melt viscosity at 70 ° C .: 11 mPa · s, electric resistance value: 130 MΩcm) was used.
The lubricant supply flow path was made of a stainless steel pipe having an inner diameter of 6 mm, and used was equipped with a lubricant tank capable of dissolving (heating and dissolving at 80 ° C.) and holding (holding at 70 ° C.) a solid lubricant. The outside of the pipe was covered with an electric heater so that the temperature of the solid lubricant fed from the lubricant tank could be maintained at 70 ° C.

  A head (length B: 200 mm) made of polyacetal (Delrin (registered trademark)) was used as the head of the coating nozzle. Bar-shaped infrared heaters (effective length A: 200 mm) are installed on both sides in parallel with the application nozzle (head) at a position away from the application nozzle by a distance D1 = 120 mm, and the infrared heater is connected via a voltage regulator (slidac). Connected to power.

  The temperature of the coating nozzle (head) was measured with a non-contact type radiation thermometer, and the temperature was adjusted with a voltage regulator so that the surface temperature was 70 ° C.

  Solid lubricant is applied to one side of the aluminum plate by adjusting the amount of lubricant supplied from the lubricant supply channel to the application nozzle (lubricant supply pipe) to about 3 g / min and the conveyance speed of the aluminum plate to about 20 m / min. The agent was applied electrostatically. The electrode voltage was 65 kV and the current value was 10 μA.

(Comparative Example 1)
A solid lubricant was electrostatically applied to one side of an aluminum plate by the method and apparatus according to the example except that the heater was not attached.
(Comparative Example 2)
A solid lubricant was electrostatically applied to one surface of an aluminum plate by the method and apparatus according to the example except that the attachment position (distance D1) of the infrared heater was less than 100 mm.

As a result, in the example, a solid lubricant coating layer was formed on one surface of the aluminum plate with a lubricant adhesion amount of 1.0 g / m ² .
In Comparative Example 1, the solid lubricant was misted immediately after the supply of the solid lubricant and immediately after the voltage application was started. However, the solid lubricant began to solidify and adhere to the head (coating nozzle) immediately, and the solid lubricant coagulated in the lubricant supply pipe (coating nozzle) soon and the coating nozzle was blocked. As a result, a solid lubricant coating layer could not be formed on the surface of the aluminum plate.
In Comparative Example 2, a short circuit occurs due to electric discharge between the infrared heater and the coating nozzle immediately after voltage application, the solid lubricant cannot be atomized, and a solid lubricant coating layer is formed on the surface of the aluminum plate. I could not.

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus 2 Coating nozzle 3 Lubricant supply flow path 4 Heater 5 Head 6 Ejection flow path 7 Lubricant supply pipe 8 Electrode 9 Shim 10 Metal plate 11 Solid lubricant coating layer 12 Solid lubricant coating metal plate 13 Induct bar 14 Fixing screw L Solid lubricant

Claims (2)

An apparatus for producing a solid lubricant-coated metal plate for producing a solid lubricant-coated metal plate by an electrostatic coating method,
A head made of an electrical insulator installed at a position opposite to a metal plate having a positive charge to be conveyed, and the solid lubricant in a molten state formed inside the head and opened to the metal plate side An ejection flow path to be ejected; a lubricant supply pipe made of an electrical insulator that communicates with the ejection flow path and supplies the molten solid lubricant; and the molten solid lubrication supplied to the ejection flow path An application nozzle having an electrode for applying a negative charge to the agent;
A lubricant supply channel that communicates with the lubricant supply pipe and supplies the solid lubricant that has been melted by the melting means;
A solid lubricant comprising: a heater provided between the coating nozzle and the metal plate in parallel with the coating nozzle and provided at a position where a short circuit due to discharge does not occur between the coating nozzle and the coating nozzle. Production equipment for coated metal plates. A method for producing a solid lubricant-coated metal sheet by producing a solid lubricant-coated metal sheet by an electrostatic coating method,
The apparatus for producing a solid lubricant coated metal sheet according to claim 1, wherein the application nozzle is measured with the heater in accordance with JIS K7121, and the solid lubricant has a melting peak temperature or higher and conforms to JISK7201. The solid lubricant in a molten state is ejected from the coating nozzle toward the metal plate while being heated below the continuous use temperature of the electrical insulator constituting the head and the lubricant supply pipe measured in the above manner. A method for producing a solid lubricant-coated metal plate, comprising forming a solid lubricant coating layer on the surface of the metal plate.

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