JP2578556B2 - Method of applying water-based lubricant to the surface of welding wire material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding wire or a hoop, pipe or round wire (hereinafter, referred to as a raw material).
(Referred to as "welding wire material").

[0002]

2. Description of the Related Art
As a lubricant to be applied to the surface of the welding wire, PTFE (poly-4
A fluorocarbon-based lubricant in which ethylene fluoride is dispersed has been used as a feed lubricant or a wire drawing lubricant (eg, Japanese Patent Publication No.
-17638). Since this fluorocarbon-based solid lubricant has quick drying properties, it can be applied only by immersing the welding wire.

[0003] However, although CFC 113 is an excellent solvent, it has a great effect on the global environment, and cannot be used after the year 2000 in the "Montreal Protocol", so it is urgently necessary to consider a solvent that can be used instead of CFC. ing.

[0004] On the other hand, conventionally, there are solid lubricants and liquid lubricants in which a solid lubricant substance is dispersed in an organic solvent.

However, solid lubricants have problems such as poor wire feedability. On the other hand, in the case of a liquid lubricant, if it is applied thickly by dipping, especially when applied to the application of a flux-cored wire, the liquid lubricant may enter the interior from the seam portion and cause welding defects. Had a problem.

Accordingly, a method of applying a welding wire is described below.
The application of electrostatic oiling technology is being considered. This electrostatic oiling is performed by a method using an atomizing nozzle.
3564 and JP-A-60-87997.

[0007] According to this electrostatic oiling method, fine droplets atomized by being sprayed by an atomizing nozzle by using carrier air are charged with static electricity, and the amount can be controlled to apply only to the surface of the wire. Therefore, it is suitable not only for a flux-cored wire having a seam but also for an Al solid wire or the like in which the total amount of hydrogen must be kept extremely small.

However, when the electrostatic oiling method is applied to the application of a liquid lubricant using an organic solvent, there is a problem that the organic solvent is dangerous because it is flammable.

Originally, the liquid in which PTFE is dispersed in Freon 113 becomes a lubricating substance because a solid lubricating film of PTFE is formed. In the change from “liquid to solid”, the one using fast-drying Freon 113 as the solvent was the easiest to handle and was excellent, but an aqueous lubricant which causes the same change even when water is used as the solvent is desirable. .

The present inventors have studied various hardeners (binder components) as aqueous lubricants which do not cause problems such as liquid lubricants, and as a result, have developed a novel aqueous lubricant (Japanese Patent Application No. 2002-214,197). Hei 3-348242). This is basically a lubricating liquid (aqueous Teflon liquid) in which water is used as a solvent and a solid lubricant substance such as Teflon (trade name) is dispersed in the solvent.

However, when such a water-based lubricant is applied by the above-mentioned electrostatic oiling method, it has been found that it has the following problems and is not suitable for practical use.

The problem is that the liquid to be applied is a liquid in which solids are dispersed, and has a property of solidifying when dried. Therefore, an apparatus provided with an atomizing nozzle as disclosed in JP-A-59-123564. In this case, the atomization nozzle is clogged. Since the droplets became fine mist, it was easier to dry and solidify, nozzle clogging frequently occurred, and stable operation could not be expected.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a method for effectively applying a water-based lubricant to the surface of a welding wire material.

[0014]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventor has studied to find a measure that can prevent nozzle clogging in the conventional electrostatic oil coating technique.

[0015] Among the electrostatic oiling techniques, there is Japanese Utility Model Laid-Open No. 59-1.
No. 23564, a method of atomizing using an atomizing nozzle, a method of dropping a liquid from a needle point to which a high voltage is applied to electrostatic atomization, and a method of rotating a bell cup to which a high voltage is applied to statically A method of electro-atomizing (eg, JP-A-59-145)
No. 063).

As a result of repeating various experiments for these methods, the bell cup rotary atomizing method was found to be superior in industrial production for electrostatic lubrication of a water-based lubricant. Here, the present invention has been completed.

That is, the present invention provides a method of applying a water-based lubricant to the surface of a welding wire or a hoop, a pipe or a round wire, which is a raw material thereof, by using a rotary atomizing type electrostatic oiling device. Features.

Hereinafter, the present invention will be described in more detail.

[0019]

[Action]

The rotary atomizing type electrostatic oiling device used in the present invention is originally an electrostatic oiling device for applying a thin film liquid to the surface for the purpose of rust prevention or the like in a forming process of a steel sheet. Suitable for applying lubricant, even if there is no nozzle that causes blockage, by increasing the rotation speed (centrifugal force),
This is because the droplet diameter can be reduced to some extent, and continuous and uniform coating can be performed.

The rotary atomizing type electrostatic lubricating apparatus used in the present invention may be an electrostatic lubricating apparatus having a bell cup for applying a high voltage while rotating and atomizing. It is possible. In addition, the conditions for electrostatic oiling using this apparatus can be determined as appropriate.

The apparatus proposed in Japanese Patent Application Laid-Open No. Sho 59-145063 is a rotary atomizing type. However, since the coating agent atomizing nozzle is additionally provided in a bell cup, the present invention is not applicable. When the water-based lubricant of the invention is applied, the atomizing nozzle in the bell cup is not suitable because it causes clogging.

In the case of the rotary atomizing type electrostatic oiling device used in the present invention, since water or an aqueous solvent is used for the coating agent (aqueous lubricant), the supply system is electrically isolated. It is desirable to take care that high voltage does not leak.

As the water-based lubricant, basically, a lubricant in which water is used as a solvent and a solid lubricant substance is dispersed in water is used .
To use .

For example, the water-based lubricant proposed above has a particle size of 0.1 in an aqueous polytetrafluoroethylene dispersion having polytetrafluoroethylene having a particle size of 0.1 to 0.4 μm.
A lubricant in which 5 to 40 μm of polytetrafluoroethylene is dispersed.

The aqueous polytetrafluoroethylene dispersion having a polytetrafluoroethylene having a particle diameter of 0.1 to 0.4 μm is a commercially available PTFE aqueous dispersion, and the lubricating performance is not very good as it is. However, the lubrication performance can be improved by dispersing and mixing PTFE of larger particles. If the particle diameter is less than 0.5 μm, no effect can be expected, and if it is more than 40 μm, the lubricating performance is rather deteriorated. The mixing amount of the PTFE having a large particle size is, for example, 5 g / l with respect to the coating solution.
The above is desirable.

When it is desired to improve the adhesion of PTFE to the water-based lubricant, a resin-based emulsion-type binder may be added. As a binder,
Hydroxyl groups, carboxyl groups, epoxy groups, amine groups, amide groups, nitrile groups, functional groups such as silanol groups are preferably copolymerized with a fluororesin, acrylic, vinyl acetate can also be used, Depending on the conditions of use, a thermosetting resin such as a phenol resin can be used. The amount of the binder added is 0.
1-30 vol% is recommended.

Another example of the water-based lubricant is a lubricant in which polytetrafluoroethylene having a particle diameter of 0.5 to 40 μm is dispersed in water with a surfactant. As before,
Large particles of PTFE are dispersed as a solid lubricating substance, but a surfactant is used because it is impossible to disperse PTFE only with water as a solvent. The type and amount of the surfactant are determined as appropriate. Examples of the surfactant include those obtained by completely fluorinating a hydrocarbon having a hydrophilic functional group such as a perfluoroalkyl carboxylate.

It goes without saying that various shapes and materials can be used as the welding wire material. In addition to a solid wire, a welding wire such as a flux-cored wire with or without a seam, the present invention can be applied to a hoop, a pipe, a round wire, or the like, which is a raw material thereof.

Next, examples of the present invention will be described.

[0031]

【Example】

FIG. 1 schematically shows the rotary atomizing type electrostatic oil applying apparatus used in this embodiment. In the figure, reference numeral 1 denotes a bell cup which applies a high voltage while rotating and atomizing, and is rotated by an air motor 2. 3 is an air pipe, 4 and a coating booth, 5 is a lubricant supply tank, and 6 is a lubricant recovery tank. The welding wire material W is electrically grounded, and a grounded wire mesh 7 is provided in the painting booth.

In the examples of the present invention, PTFE having a particle size distribution of 0.5 to 40 μm in water is used as a water-based lubricant as a surfactant.
Using a lubricant dispersed in (perfluoroalkyl carboxylate) using the above-described rotary atomizing type electrostatic oil coating device, the coating was dried in-line. The application condition is that the applied voltage is about 60 KV and the lubricant supply amount is about 50 to 150 cc / mi.
n.

Further, the comparative example is a case where the same water-based lubricant is applied to the dough pickling system by the process of pickling and drying.

Test No. 1 is an Al wire (product diameter 1.6 mm).
This is an example applied to Although the feed resistance of the wire is low in both the present invention example and the comparative example, in the comparative example, when the gas shielded arc welding using 100% Ar, the bead surface was PT
The carbonized FE covered and exhibited poor appearance. On the other hand, in the example of the present invention, the bead was applied uniformly, and exhibited an optimum bead appearance while ensuring the feeding property. The arc stability was also good.

Test No. 2 is an example of application to a flux-cored wire having a seam (product diameter: 1.2 mm). In the example of the present invention, even a water-based lubricant can be applied only to the wire surface without infiltrating moisture from the seam and flux being wet, and without increasing the amount of hydrogen (Flon 113
(Equivalent to a lubricant using). On the other hand, the comparative example was a product coated by the dough dipping method, and although the wire feed resistance was low, the amount of wire hydrogen was excessive.

[0037]

[0038]

As described in detail above, according to the present invention,
An aqueous lubricant that does not use Freon 113 as a solvent can be applied to the surface of the welding wire material, and a welding wire free of welding defects can be provided. In particular, the elimination of chlorofluorocarbon in the manufacturing process is possible, and the effect of contributing to global environmental protection is extremely large.

[Brief description of the drawings]

FIG. 1 is a view schematically showing a rotary atomizing type electrostatic oil applying apparatus used in an embodiment.

[Explanation of symbols]

 1 Bell cup 2 Air motor 3 Air piping 4 Application booth 5 Water-based lubricant supply tank 6 Lubricant recovery tank 7 Wire mesh W Welding wire

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B05D 7/20 B05D 7/20 B23K 35/40 330 B23K 35/40 330 (56) References JP JP-A-54-29866 (JP, A) JP-A-60-42494 (JP, A) JP-A-57-24659 (JP, A) JP-A-3-26371 (JP, A) JP-A-2-298596 (JP) JP-A-1-289896 (JP, A) JP-A-60-87997 (JP, A)

Claims (2)

(57) [Claims] 1. The particle size of a welding wire or the surface of a hoop, pipe or round bar, which is a raw material thereof, is determined.
Aqueous with 0.1-0.4 μm polytetrafluoroethylene
In the polytetrafluoroethylene dispersion, a particle size of 0.
5-40 μm high molecular weight polytetrafluoroethylene dispersed therein
A method of applying a water-based lubricant to the surface of a welding wire material, wherein the water-based lubricant is applied by using a rotary atomization type electrostatic oiling device. 2. The method according to claim 2, wherein the surface of the welding wire is submerged in water.
Water-based lubrication characterized by applying a water-based lubricant obtained by dispersing a high molecular weight polytetrafluoroethylene having a particle diameter of 0.5 to 40 [mu] m with a surfactant using a rotary atomizing electrostatic oiling device. A method of applying an agent to the surface of a welding wire material.