JPH0716537A - Coating of wire - Google Patents

Abstract

PURPOSE:To simply coat a wire by forming a coating substance film on a linear article such as a wire so as to obtain uniform thickness in the circumferential direction of the linear article. CONSTITUTION:A running wire 10 is washed in a washing bath 14 to be immersed in a borax bath 16. The wire 10 having the borax aq. soln. bonded thereto is passed on a removing roll 18 so that the roll 18 removing the excessive borax aq. soln. comes into contact with the wire 10 from below and air is sprayed toward the contact area of the removing roll 18 with the wire 10 by the nozzle 20 of the air sprayer positioned above the removing roll 18 to remove the excessive borax aq. soln. on the wire and, thereafter, the wire is dried in a drying and heating oven 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for coating a wire, and more particularly to a method for coating a wire which is suitable for pretreatment of wire drawing of a metal wire and which can form a uniform coating layer.

[0002]

2. Description of the Related Art Conventionally, in order to coat a coating substance on a wire, that is, a linear object, the wire is immersed in a liquid coating substance bath, and excess liquid coating substance deposited on the wire is contacted with a removal roll. It has been carried out by subjecting the wire to a coating material, for example, by removing the solvent and then subjecting the wire to a drying step.

In particular, when a wire made of a metal such as a steel cord is drawn by using a dry lubricant, a borax chemical conversion film is formed on the surface of the wire in advance to adhere the lubricant. To improve wire drawability. The borax chemical conversion coating is required to have a predetermined uniform thickness. That is, if the thickness is thin, it is difficult to completely cover the surface of the wire, and if the coating is too thick, it is difficult to dry and the borax chemical conversion coating becomes a hydrate of decahydrate having poor mechanical strength. There has been a problem that the wire is peeled off during the wire treatment to reduce the wire drawability.

The above-mentioned method of removing excess coating material aqueous solution by contacting a removal roll to coat a wire with a coating having a uniform thickness in the circumferential direction was applied to the formation of a borax chemical conversion coating on a metal wire. However, although the excess borax solution adhering to the lower part of the wire is removed, the excess solution remaining on the upper part moves to the lower part by gravity during the transportation to the drying process, and a thin film on the upper part, and on the lower part A thick film was formed and it was not possible to obtain a film having a uniform thickness.

[0005]

As described above, when a coating material is coated on a linear object such as a wire, a uniform film can be formed in the circumferential direction of the wire, and a simple wire can be formed. A coating method has been sought.

That is, the object of the present invention is to improve the wire drawability of a metal wire by forming a uniform coating in the circumferential direction of the wire, especially on the metal wire for wire drawing treatment. It is to provide a simple wire coating method.

[0007]

The method for coating a wire according to claim 1 of the present invention comprises the steps of immersing a traveling wire in a bath of a coating substance, and passing the roll through which excess coating substance is removed. It is characterized in that gas is jetted toward a contact area between the roll and the wire from a gas jetting unit located opposite to the roll with the wire sandwiched therebetween, and thereafter, the step of solidifying the coating material film is performed.

According to a second aspect of the present invention, in the method for coating a wire, when a metal wire running in a horizontal direction is dipped in a borax solution and passed over a roll for removing excess borax solution. It is characterized in that air is jetted from an air blowing device located above, and thereafter, a borax film is dried.

[0009]

As described above, if the wire immersed in the coating material bath is only brought into contact with the roll for removing the excess coating material (FIG. 3 (A)), the excess wire adhered to the lower part of the wire during contact with the roll is removed. Only the coating material is removed (Fig. 3
(B)) Since the excess coating material remaining above the wire moves downward due to gravity during traveling of the wire, the coating film of the coated wire obtained through the solidification step of the coating material has a thin upper portion. , The bottom is thick and uneven (Fig. 4
(B)). In the wire coating method of the present invention, when the traveling wire is immersed in a coating substance bath and passed through a roll for removing the excess coating substance, a gas jet located opposite the roll while sandwiching the wire Since the gas is jetted from the means toward the contact area between the roll and the wire (FIG. 2 (A)), the excess coating material adhered below the wire at the time of contact with the roll is adhered above the wire by the removal roll. The surplus coating substance and the surplus coating substance adhering to the removal roll are removed by the gas injection (FIG. 2 (B)), respectively, and then subjected to the solidification step of the coating substance film, and thus obtained. A film having a uniform thickness is formed on the covered wire (FIG. 4A).

[0010]

【Example】

Example 1 FIG. 1 is a schematic view showing an apparatus used in Example 1 of the wire coating method of the present invention.

FIG. 2 (A) is an enlarged schematic view of the vicinity of the injection port of the device for injecting gas in the wire coating method of the present invention, and FIG. 2 (B) shows the state of removing excess coating material. It is a schematic sectional drawing of a wire.

A high carbon steel wire 10 having a wire diameter of 3 mm and formed in advance by a wire drawing treatment is a winding roll 12 at a payout portion.
Out of. Since the wire drawing lubricant remains adhered to the surface of the wire 10, the wire 10 is washed in a warm water washing bath 14 filled with ion-exchanged water at 70 to 80 ° C., and the wire drawing lubricant adhered to the surface. Agents and dirt are removed. As the washing bath, an alkaline degreasing bath using an aqueous sodium hydroxide solution can be used in addition to the warm water washing bath. The washed wire 10 is subsequently immersed in the borax bath 16. The borax bath 16 contains 170 for 1 liter of water.
It is filled with an aqueous borax solution at 85 to 95 ° C. in which g of Na ₂ B ₄ O ₇ is dissolved. The temperature of the borax aqueous solution used in the borax bath is preferably 60 ° C. or higher. The wire 10 to which the borax aqueous solution is attached is such that a roll (hereinafter, referred to as a removal roll) 18 for removing an excess borax solution having a diameter of 100 mm comes into contact with the removal roll 1 from below.
Pass 8. Above the removing roll 18, a filter is arranged at the air intake, and a nozzle 20 of an air blowing device including a compressor, a heater and a blowing nozzle is arranged.
Wire 1 toward the contact area between wire 8 and wire 10.
It is sprayed uniformly at a wind speed of 45 m / sec over a length of 15 mm in the traveling direction of 0. As a result, the excess coating material attached below the wire is removed by the removal roll,
The excess coating substance attached to the upper part of the wire and the excess coating substance attached to the removal roll were removed by the gas injection. The wire 10 from which the excess aqueous borax solution has been removed continues to run, and in the drying heating furnace 22 at 100 ° C.,
The wire is subjected to a drying step, the wire periphery is covered with a borax chemical conversion film, and the wire is wound around the winding roll 24 of the winding portion.

Comparative Example 1 FIG. 3 (A) is an enlarged schematic view of the vicinity of a roll for removing surplus substances in the conventional method of not injecting gas,
FIG. 3B is a schematic cross-sectional view of the wire showing a state in which the excess coating material is removed.

In the above coating method, except that air is not blown by the air blowing device,
A borax chemical conversion coating wire was obtained in the same manner as in Example 1.

(Measurement of amount of borax and evaluation of uniformity)
Wash the resulting borax chemical conversion coating wire with warm water,
The amount of borax attached was determined by quantitatively analyzing boron atoms in the cleaning liquid by plasma emission spectrometry.

Further, the strength of Na is obtained by using an energy dispersive X-ray analyzer, and F used in the wire is measured.
The amount of borax adhered was measured by evaluating the peak ratio with e. The measurement is performed at four points in the circumferential direction of the wire, and the value obtained by dividing the amount of borax maximum adhesion of the four points by the minimum amount of adhesion is defined as the film non-uniformity. However, it was evaluated that the thickness of the film was uniform.

FIG. 4 (A) is a schematic sectional view of the borax chemical conversion coating wire obtained in Example 1, and FIG.
FIG. 3 is a schematic cross-sectional view of a borax chemical conversion coating wire obtained in Comparative Example 1.

(Evaluation of wire drawability) The obtained borax chemical conversion coating wire was subjected to wire drawing treatment in the next step to evaluate wire drawability. Wire diameter of 3.0mm to 1.00mm
The diameter of the final die when the diameter is reduced is 0.02 mm due to wear.
The wire drawability was determined by measuring the length of the wire that had been drawn by the time it increased. The evaluation of the wire drawability was represented by an index with the value of Comparative Example 1 being 100, and those having an index larger than 100 were evaluated as having good wire drawability.

The above results are shown in Table 1.

[0020]

[Table 1]

As shown in Table 1, the amount of borax deposited on the coated wire of Example 1 was 1.7 g / m ² ,
The non-uniformity was 2.5 times and the drawability index was 140. Compared with the coated wire obtained in Comparative Example 1 which is a conventional method, this has an appropriate amount of adhesion, non-uniformity is improved to 1/4, and wire drawability is also improved by 40%, which is excellent. It has been revealed that the above effect is exhibited.

In the present embodiment, not only the borax solution for coating the wire can be made uniform in the circumferential direction of the wire, but also the amount of the solution adhering to the wire can be made constant and adhered. Since the liquid amount is constant, it is possible to deposit an arbitrary amount of borax on the wire to a uniform thickness by controlling the concentration of the borax solution. Normal,
The amount of borax to be attached to a steel wire, it is preferable from the viewpoint of drawability is ^{1.1g / m 2 ~2.3g / m 2} . If it is less than 1.1 g / m ^2, it is difficult to coat the wire completely uniformly, and if it is more than 2.3 g / m ² , it is easy to form a decahydrate chemical conversion film of decahydrate having a low mechanical strength in the drying process. In both cases, it is difficult to obtain a wire with high wire drawability, which is not preferable.

The gas injected near the removal roll is, for example, oxygen, nitrogen, or the like as long as the coating material is not damaged.
Although air or the like can be arbitrarily selected, it is usually preferable to use air from the viewpoint of easy handling and price. Further, the temperature of the gas to be sprayed can also be arbitrarily selected within a range that does not damage the wire or the coating substance, and particularly when using a borax aqueous solution as the coating solution and heat drying in the subsequent drying step as in this example. By using warm air,
At the same time as removing the excess aqueous solution, the heat for drying can be applied to the wire, and the film with good wire drawability can be formed more efficiently.

As the gas jetting means, in addition to the air blowing device equipped with the compressor, an air blowing device equipped with a pump, a container filled with compressed gas to be supplied, a valve for adjusting the jetting amount, and a spraying nozzle are provided. A device equipped with a gas blowing device, etc., such as a pump, a compressor, etc., for pressing a gas, a transfer path, a pump, a compressor control device, a valve, etc. adjusting device, and a blowing nozzle, and optionally a gas heating device such as a heater. It can be used arbitrarily.

In the present embodiment, the wire is washed in the washing bath before being immersed in the borax bath, but the wire from which deposits and dirt have been removed by washing or the like is previously coated with the method of the present invention. It goes without saying that the washing bath can be omitted if desired.

In the present embodiment, the case of the borax chemical conversion coating on the steel wire for improving the adhesion of the lubricant in the dry drawing is described, but the coating method of the present invention uses the wire as a solution. Any method can be applied as long as the coating substance is solidified by a means such as dipping and then drying, solvent removal, or the like. For example, when a steel wire is dipped in a lime film solution, dried and solidified to form a film, a copper wire is dipped in a thermoplastic resin and then cooled to form an insulating film, the wire is an organic solvent. It can be used for various purposes such as when a film with high decorativeness is formed by immersing in a resin solution dissolved in, and then removing the solvent.

The running direction of the wire is preferably horizontal, but it is also possible to provide the conveying path with heights in order to reduce the installation area of the machine. When the traveling direction of the wire is not horizontal, it is necessary to provide a means for preventing the removed excess coating material from reattaching to the wire in the gas injection area.

[0028]

According to the wire coating method of the present invention,
A coating of a coating material with a uniform thickness can be easily formed, and in particular, a metal wire for wire drawing treatment can be easily formed with a uniform borax chemical conversion coating in the circumferential direction of the wire. The wire drawability of the wire can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view showing an apparatus used in Example 1 of a wire coating method of the present invention.

FIG. 2 (A) is an enlarged schematic view of the vicinity of the gas injection port of the device for injecting gas in the wire coating method of the present invention, and FIG. 2 (B) shows a wire showing a state of removing excess coating material. It is a schematic sectional drawing.

FIG. 3 (A) is an enlarged schematic view around a removing roll in a conventional wire coating method, and FIG. 3 (B) is a schematic cross-sectional view of a wire showing a state of removing excess coating material.

4 (A) is a schematic cross-sectional view of the borax chemical conversion coating wire obtained in Example 1, and FIG. 4 (B) is Comparative Example 1
It is a schematic sectional drawing of the borax chemical conversion coating wire obtained by.

[Explanation of symbols]

 10 wire 16 borax bath 18 removal roll 20 nozzle of air blowing device

Claims (2)

[Claims] 1. When the running wire is immersed in a bath of coating material and passed through a roll for removing excess coating material, the wire is sandwiched between the roll and a roll for removing the roll by a gas jetting means located opposite the roll. A method for coating a wire, comprising injecting a gas toward a contact region of the wire, and then subjecting the coating material film to a solidification step. 2. A horizontal metal wire is immersed in a borax solution, and when it is passed over a roll for removing excess borax solution, air is jetted from an air blowing device located above. Then, the method for coating a wire is characterized by subjecting the borax coating to a drying step thereafter.