Coating forming apparatus

Abstract

Even with thin diameter wires, the surface coating dries sufficiently in a short time. [Solution] The coating forming apparatus includes a pair of grooved guide rollers 12, 13 through which a wire 1 is alternately stretched, a coating tank 11 that stores a coating liquid 30 in an amount sufficient to immerse the entire pair of grooved guide rollers 12, 13, a heater 14 provided in the coating tank 11 to heat the coating liquid 30, an upper sheave 22 provided above the coating tank 11 over which the wire 1 unwound from the coating tank 11 is hung, an air wipe 15 provided between the coating tank 11 and the upper sheave 22 to blow air onto the wire 1 as it travels from the coating tank 11 toward the upper sheave 22, and a vertical drying oven 16 provided above the coating tank 11 to surround the wire 1 as it travels toward the upper sheave 22 and form a high-temperature atmosphere.

Description

[Technical Field]

[0001] The present invention relates to a film forming apparatus. [Background Art]

[0002] In wire drawing processing for reducing the diameter of a thick wire, a die having a conical hole with a larger diameter at the inlet side and a smaller diameter at the outlet side is used. A wire having a diameter larger than the small diameter of the hole of the die is passed through the die and drawn out from the die, thereby reducing the diameter of the wire.

[0003] When the wire passes through the die, the wire and the die rub strongly against each other. In order to reduce friction between the wire and the die and prevent the seizure phenomenon in which a part of the wire is welded to the die due to high temperature and high pressure generated when the wire passes through the die, a film having a lubricating effect or an effect of preventing welding is formed on the surface of the wire in advance (hereinafter referred to as the film forming step).

[0004] The film forming step includes a "chemical reaction method" in which a film agent (for example, zinc phosphate) is attached to the wire surface through a chemical reaction, and a "coating method" in which the film agent is attached to the wire surface by coating the wire surface with the film agent and drying the coating.

[0005] The film agent used in the coating method generally has lower production cost than the film agent used in the chemical reaction method, and is characterized in that the film is easily removed after wire drawing. In addition, in recent years, environmental measures have been required, and sludge and the like generated when zinc phosphate is produced by the chemical reaction method may be regulated as industrial waste.

[0006] Patent Document 1 discloses a film treatment method and a wire drawing apparatus for forming a lubricating coating mainly composed of a water-soluble inorganic salt on a wire rod. [Prior Art Literature] [Patent Literature]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 5-317954

[0008] The wire drawing apparatus described in Patent Document 1 includes a straightening machine 11 for straightening the wire, a shot blast 13 for descaling the wire surface, a high-frequency heating device 15 for preheating the wire to 70-150°C, an inorganic salt deposition tank 17 for storing an aqueous solution of water-soluble inorganic salt at a constant temperature of 85-95°C, a wire raising device 19 for vertically raising the wire that has passed through the inorganic salt deposition tank 17 and then lowering it, a blower 21 for promoting the removal of liquid from the surface of the raised wire, a hot air blowing pipe 23 for blowing hot air onto the descending wire, and a wire drawing die device 25.

[0009] When the wire diameter is large, the coating adhering to the wire surface dries easily while the wire is moving. However, when the wire diameter is small, the coating does not dry easily while the wire is moving. If the wire is passed through the die before the coating has dried, the coating is scraped off as the wire passes through the die, reducing the lubricating effect. [Overview of the project]

[0010] The purpose of this invention is to enable the surface coating of even thin-diameter wires to dry sufficiently in a short amount of time.

[0011] This invention also aims to reduce the installation area of ​​the wire pre-processing equipment before the wire drawing process.

[0012] The coating apparatus according to this invention forms a coating on the surface of a moving wire and comprises a coating tank containing a coating agent solution in an amount sufficient to immerse the entire pair of grooved guide rollers, a heater provided in the coating tank for heating the coating agent solution, an upper sheave provided above the coating tank on which the wire unwound from the coating tank is hung, an air wipe provided between the coating tank and the upper sheave for blowing air onto the wire moving from the coating tank toward the upper sheave, and a vertical drying oven provided above the coating tank to surround the wire moving from the coating tank toward the upper sheave and create a high-temperature atmosphere. The wire includes wires and cords.

[0013] According to this invention, the wire can be immersed in a heated coating solution for a predetermined time, allowing the wire to accumulate heat while immersed in the coating solution in the coating tank. Furthermore, excess coating solution is blown off by an air wipe, and the wire then travels through a high-temperature vertical drying oven, allowing the coating solution on the wire surface to dry thoroughly in a short time. In addition, since the vertical drying oven is located above the coating tank, the overall installation area of ​​the coating forming apparatus is small, resulting in a compact coating forming apparatus.

[0014] The pair of grooved guide rollers installed in the coating tank may be arranged horizontally with a gap between them, or vertically. Arranging the pair of grooved guide rollers vertically allows for a smaller installation area for the coating tank, resulting in a more compact coating forming apparatus.

[0015] In one embodiment, the coating solution stored in the coating tank is heated to 90°C or higher. By increasing the heat storage capacity of the wire, the coating solution on the surface of the wire can be dried in a shorter time.

[0016] The larger the diameter of the wire, the longer it takes for the wire's temperature to reach the temperature of the coating solution. Preferably, the wire is immersed in the coating solution for 5 seconds or more, and is passed over the pair of grooved guide rollers multiple times. While a longer distance between the pair of grooved guide rollers can also increase the immersion time, it increases the footprint of the coating tank. By increasing the number of times the wire is passed over the pair of grooved guide rollers, the immersion time can be increased without increasing the footprint of the coating tank.

[0017] Preferably, the upper sheave is provided at the top of the vertical drying oven. The coating solution on the wire surface can be thoroughly dried inside the vertical drying oven from the time it leaves the coating tank until it reaches the upper sheave, and further until it is turned over by the upper sheave and removed from the vertical drying oven.

[0018] In one embodiment, the vertical drying oven is equipped with a hot air device that supplies hot air at 100°C or higher. By running the wire through a high-temperature atmosphere with flowing hot air, the coating solution on the surface of the wire can be thoroughly dried in a short time. [Brief explanation of the drawing]

[0019] [Figure 1] This is a partially broken perspective view of a coating device. [Figure 2] This is a magnified cross-sectional view of the air wipe and the area around it. [Figure 3] This is a cross-sectional view of a coating apparatus in another embodiment. [Figure 4] This is a cross-sectional view of a coating apparatus in another embodiment. [Figure 5] This graph shows the relationship between the air pressure of the compressed air blown onto the wire and the amount of coating adhering to the wire's surface. [Examples]

[0020] Figure 1 is a perspective view of the coating apparatus.

[0021] The film forming apparatus is an apparatus that forms a film in a short time on the surface of a wire (element wire) 1, particularly a steel wire 1 with a small diameter, for example, a diameter of 4 mm or less before wire drawing, and comprises: a film tank 11 storing a solution obtained by diluting a water-soluble film agent (oil agent) with water (hereinafter referred to as a film solution 30); a pair of guide rollers 12 and 13 provided in the film tank 11, around which the wire 1 is wound a plurality of times; a heater 14 for heating the film solution 30 in the film tank 11; an air wipe 15 for blowing air to the wire 1 to which the film solution 30 adheres; and a vertical drying furnace 16 for drying the film solution 30 adhering to the wire 1. A water-soluble film agent having a lubricating effect is used.

[0022] The wire 1 paid out from a pay-out reel (not shown) has its direction changed by a sheave 21 and travels into the film tank 11 storing the film solution 30.

[0023] The film tank 11 has a rectangular parallelepiped shape with a rectangular bottom surface and a rectangular top surface. Fine pores (an inlet and an outlet) through which the wire 1 can pass are formed respectively near one short side and near the other short side of the rectangular top surface. The wire 1 enters the film tank 11 through the inlet fine pore formed in the top surface of the film tank 11, and exits the film tank 11 through the outlet fine pore.

[0024] In the film tank 11, a pair of rotatable grooved guide rollers 12 and 13 formed with about 4 to 5 plurality of guide grooves are provided side by side laterally in a direction connecting an inlet side and an outlet side with a space therebetween. The wire 1 is alternately wound around the guide grooves of the inlet-side guide roller 12 and the guide grooves of the outlet-side guide roller 13, and reciprocates a plurality of times between the inlet-side guide roller 12 and the outlet-side guide roller 13. In Fig. 1, illustration of the grooves and bearings of the grooved guide rollers 12 and 13 is omitted.

[0025] The entire pair of guide rollers 12 and 13 is immersed in the film solution 30 stored in the film tank 11. The entire wire 1 wound a plurality of times between the pair of guide rollers 12 and 13 is also immersed in the film solution 30.

[0026] A heater 14 is provided on the inner bottom surface of the coating tank 11. The heater 14 heats the coating liquid 30 stored in the coating tank 11 to about 90°C. Since the wire 1 is passed over a pair of guide rollers 12 and 13 immersed in the coating liquid 30 multiple times, the wire 1 is immersed in the coating liquid 30 in the coating tank 11 for a relatively long time until it comes out of the coating tank 11. While the wire 1 is immersed in the coating liquid 30, the temperature of the wire 1 rises to the temperature of the coating liquid 30, i.e., about 90°C. The larger the diameter of the wire 1, the longer it takes for the wire 1 to reach the temperature of the liquid. For example, the number of times the wire 1 is passed over the pair of guide rollers 12 and 13 is adjusted so that the wire 1 is immersed in the coating liquid 30 for 5 seconds or more.

[0027] A wire 1 that has sufficiently accumulated heat and has the coating liquid 30 attached to its surface is fed out from the exit-side guide roller 13. The wire 1 that has passed through the exit pore of the coating tank 11 and exited the coating tank 11 is placed on the upper-mounted sheave 22. The upper-mounted sheave 22 is located above the exit-side guide roller 13, and the wire 1 that has exited the coating tank 11 moves vertically upward. The coating liquid 30 attached to the surface of the wire 1 tends to sag due to gravity the thinner the diameter D of the wire 1 is, and tends to cause unevenness in the thickness of the coating liquid 30. However, since the direction of travel of the wire 1 is vertical, unevenness in the thickness of the coating liquid 30 attached to the surface of the wire 1 is less likely to occur compared to when the wire 1 is traveled horizontally.

[0028] An air wipe 15 is provided above the exit-side guide roller 13 (outside the coating tank 11), and a vertical drying oven 16 is installed further above the air wipe 15. The aforementioned upper-mounted sheave 22 is located in the upper part of the vertical drying oven 16. The wire 1, which exits the coating tank 11 and moves vertically upward, passes through the air wipe 15 and the vertical drying oven 16.

[0029] Figure 2 is an enlarged longitudinal cross-sectional view of the air wipe 15 and the area around the air wipe 15.

[0030] The air wipe 15 has a ring-shaped outer form, through which the wire 1, running vertically upward, passes. An annular discharge hole 15a is provided on the inner surface of the air wipe 15, and air is discharged from this annular discharge hole 15a toward the center of the ring of the air wipe 15. The air from the air wipe 15 is blown onto the surface of the wire 1 passing through the center of the ring, thereby making the coating liquid 30 (coating 1a) adhering to the surface of the wire 1 a nearly uniform thickness. The excess coating liquid 30 blown off by the air wipe 15 flows down the surface of the vertically running wire 1 and returns to the coating tank 11.

[0031] The amount of coating 1a that adheres to the surface of the wire 1 can be controlled by the pressure of the air blown onto the wire 1 from the air wipe 15. Figure 5 shows the air pressure (horizontal axis) (unit: MPa) and the amount of coating (vertical axis) (unit: g / m) when the liquid concentration of the coating liquid 30 is 26.5 wt% and the running speed of the wire 1 is 100 m / min. 2 This graph shows the relationship between the amount of adhesion and the amount of adhesion. For example, 4-5 g / m 2 To achieve this, you should blow air at a pressure of approximately 0.015 to 0.020 MPa.

[0032] Returning to Figure 1, the wire 1, with a coating 1a of uniform thickness formed on its surface by the air wipe 15, travels inside the vertical drying oven 16. The wire 1 enters the vertical drying oven 16 through pores made in the inlet surface of the vertical drying oven 16 (the surface facing the air wipe 15). The vertical drying oven 16 has a shape in which the internal space at the bottom is somewhat narrow, and the internal space widens as it approaches the top.

[0033] Hot air from a hot air device (not shown) is supplied into the vertical drying oven 16, and the internal temperature is set to approximately 100°C. By the time the wire reaches the upper-mounted sheave 22 located at the top of the vertical drying oven 16, the coating 1a on the surface of the wire 1 is at least semi-dry to the point where it is no longer sticky.

[0034] The wire 1 moves vertically downwards as its direction of travel is changed downwards by the sheave 22 installed above. While moving vertically downwards, the drying of the coating 1a inside the vertical drying oven 16 continues. The thoroughly dried wire with the coating 1a (hereinafter referred to as coated wire 2) exits the vertical drying oven 16 through an outlet pore opened in the bottom surface (bottom surface of the wide internal space). The coated wire 2 is passed over the sheave 23 to change direction and proceeds to the wire drawing machine (not shown). In the wire drawing machine, the coated wire 2 is passed through a die and drawn.

[0035] The wire 1 accumulates heat when immersed in the heated coating solution 30 in the coating tank 11 for a predetermined time, and since the wire 1 also travels through a high-temperature vertical drying oven 16, the coating 1a on the surface of the wire 1 can be thoroughly dried in a short time. Furthermore, since the vertical drying oven 16 is located above the coating tank 11, the overall installation area of ​​the coating forming apparatus is small. A compact coating forming apparatus is realized.

[0036] A vertical drying oven 16 of a certain height is required to thoroughly dry the coating 1a on the surface of the wire 1. Generally, wire manufacturing plants have high ceilings, so there are no obstacles to installing a vertical drying oven 16 of sufficient height.

[0037] Figure 3 is a schematic cross-sectional view of a film-forming apparatus of another embodiment, shown from the side. The installation positions of the air wipe 15 and the vertical drying oven 16 differ from those of the film-forming apparatus in Figure 1.

[0038] An air wipe 15 and a vertical drying oven 16 are located above the inlet-side guide roller 12. The wire 1, which is stretched multiple times between the inlet-side guide roller 12 and the outlet-side guide roller 13, is unwound from the inlet-side guide roller 12.

[0039] Figure 4 is a cross-sectional view corresponding to Figure 3, showing a film-forming apparatus of yet another embodiment. It differs from the film-forming apparatus shown in Figures 1 and 3 in that the film tank 11 is installed vertically, and the pair of guide rollers 12 and 13 are arranged vertically side by side. The installation area occupied by the film tank 11 is small, and the entire film-forming apparatus can be made even more compact. [Explanation of Symbols]

[0040] 1 wire 2. Coated wire 11 Coating tank 12,13 Guide rollers 14 Heater 15 Air Wipes 16. Vertical drying oven 21, 22, 23 Sieve

Claims

1. A coating forming apparatus for forming a coating on the surface of a moving wire, A coating tank comprising a pair of grooved guide rollers through which the above-mentioned wires are alternately stretched, and a coating solution containing an amount sufficient to completely immerse the pair of grooved guide rollers, A heater is provided in the above coating tank to heat the above coating agent solution. An overhead sheave is provided above the coating tank, on which the wire material unwound from the coating tank is hung. An air wipe is provided between the above coating tank and the above-upper installed sheave, and blows air onto the wire running from the coating tank toward the upper installed sheave, and The system includes a vertical drying oven located above the coating tank, which surrounds the wire material as it travels from the coating tank toward the upper-mounted sheave, creating a high-temperature atmosphere. A coating forming apparatus.

2. The pair of grooved guide rollers described above are arranged side by side with a gap between them. The coating forming apparatus according to claim 1.

3. The pair of grooved guide rollers described above are arranged vertically with a gap between them. The coating forming apparatus according to claim 1.

4. The coating agent solution stored in the above coating tank is heated to 90°C or higher. The coating forming apparatus according to claim 1.

5. The wire is passed over the pair of grooved guide rollers multiple times so that it is immersed in the coating solution for a period of 5 seconds or more. The coating forming apparatus according to claim 1.

6. The above-mentioned upper-mounted sieve is installed in the upper part of the above-mentioned vertical drying oven. The coating forming apparatus according to claim 1.

7. The above vertical drying oven is equipped with a hot air device that supplies hot air at 100°C or higher. The coating forming apparatus according to claim 1.

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