JPS5829173Y2 - Equipment for coating the surface of steel strip or metal-plated steel strip with chemical conversion treatment liquid - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for coating a strip with a chemical conversion treatment liquid, and in particular, coats steel or steel with Zn or AI.

Continuous chromate treatment for dip-plated or electroplated strips with metals such as Sn, Pb, and Cr.
The present invention relates to an apparatus that can easily switch between treatment solutions of different types and concentrations when performing phosphoric acid film treatment, and can efficiently form thin film coatings with different surface properties.

When coating a strip with a chemical conversion treatment solution, for example, in the case of chromate treatment, users desire several types of surface textures with different concentrations.

In addition, in response to requests for phosphate coatings, switching must be performed efficiently using the same device.

In this case, the conventional pot method was not necessarily sufficient in terms of efficiency, yield, etc.

For this purpose, the applicant performs spraying, wiping, and drying of the processing liquid while the strip is moving vertically, and constructs a plurality of processing liquid supply systems including a processing liquid circulation tank, a pump, a nozzle, and a switching valve. We have developed a device that allows for easy switching of processing liquids, avoids the risk of explosion (when using organic solvents), and allows for the same heating conditions on the front and back surfaces of the processing surface.

However, although such equipment allows for efficient production, the application state of the processing liquid is unstable because the liquid blown out from the liquid supply nozzle is disturbed by the secondary flow after the strip collides with the gas nozzle. This caused problems such as the formation of uncoated areas.

The present invention is an attempt to solve the above drawbacks, and is a distant relative of the above object by providing a strip clamping roll below the liquid supply nozzle.

That is, the present invention raises a steel strip or a metal-plated steel strip almost vertically, and arranges a plurality of nozzles that supply a chemical conversion treatment liquid to the surface of the steel strip to be passed, and each nozzle stores a chemical conversion treatment liquid. A nozzle that supplies cleaning water is placed at the top of a nozzle group that supplies chemical conversion treatment liquid, and a wiping nozzle wipes away excess liquid above the nozzle group. In an apparatus that is provided with a cover that prevents scattering of the chemical conversion treatment liquid and collects the chemical conversion treatment liquid around the nozzle and the group of chemical conversion treatment liquid supply nozzles, a nozzle is installed in contact with the steel strip below the nozzle group that supplies the chemical conversion treatment liquid. This apparatus coats the surface of a steel strip or metal-plated copper strip with a chemical conversion treatment solution, and is characterized by being provided with a flat roll that temporarily stores the chemical conversion treatment solution supplied from the copper strip on the surface of the copper strip.

Next, the present invention will be explained with reference to drawings.

In FIG. 1, the strip S is the deflector roll 2
, then travels approximately vertically upward via a zinc roll 1, and is then turned horizontally by a deflector roll 2 and transported.

The strip S that has passed through the zinc roll 1 is transferred to the clamping roll 6.
．． 7 is brought into contact.

The clamping rolls 6.7 are arranged at different levels to sandwich the strip S, and press the strip S from both sides, so that the strip S passes around the clamping roll 6.7 in an arc.

Therefore, the liquid blown out from the nozzle and the excess liquid from the wiping flow down, and a liquid pool 19 expands in the width direction at the contact area between the strip S and the clamping roll 6.7 as shown in FIG. You can remove unapplied areas by moistening the area.

By providing the rolls 6.7, there is an effect of preventing vibration of the strip and correcting the C warp, and it is possible to further improve coating uniformity.

Further, the rolls 6, 7 are arranged at different levels, with gaps between the rolls, so that the strip can easily pass through the welded portion.

The roll 6.7 is made of a material such as rubber, synthetic resin, or iron, and has a roll diameter of 100 mm.

In this case, the nozzle group 3 is composed of a water washing nozzle 10 on the uppermost stage and nozzles 11, 12, and 13 for different chemical treatment baths, respectively.

Nozzles 11, 12.13 are respectively valves 15.16.17
, chemical conversion bath tank 2 via pumps 28, 27, 26
5, 24. The pump is connected to 23, and this tank 23
．． 24 and 25 are designed to store, for example, chromate solutions or phosphate solutions of different concentrations.

4.5 is designed to inject pressurized gas with a gas nozzle to remove excess chemical conversion treatment liquid applied to the strip.

Next, gas nozzles 4, 5, nozzle group 3, clamping roll 6°7
The part of the zinc roll 1 is surrounded by a cover 29 for recovering the chemical conversion treatment liquid, a liquid receiving tray 30 is formed at the bottom of the cover 29, and a conduit is connected from the liquid receiving tray 30 to the processing bath tank 23 through a valve 19°20.21. , 24.25.

Reference numeral 22 denotes a cleaning drainage tank, which is connected to a liquid receiving tray 30 via a valve 18.

In the figure, 31 is a drainage pump.

With this structure, when processing with the A liquid in the processing liquid tank 23, the valves 17 and 19 are opened, the valves 16.15 and the valves 18 and 20.21 are closed, and the pump 26 is operated. Spray the liquid onto the strip.

The treatment liquid A is applied to the strip while circulating through the pump 26, valve 17, nozzle 13, and liquid receiving tray 30 via the valve 19 and tank 23.

When converting processing liquid A to processing liquid B, valve 19.17
is closed, the valves 14 and 18 are closed, and fresh water is blown out from the washing nozzle 10 to wash the inside of the cover 29, the rolls 6.7, and the zinc roll 1, and then the washing waste water is discharged into the tank 22.

Next, close the flush valves 14 and 18, and close the valve 20°1.
6 is opened, the pump 27 is operated, and the B liquid in the tank 24 is sprayed from the nozzle 12.

When spraying liquid C, it is carried out in the same manner as in the case of liquid B.

The naori bar 29 is provided with a gas outlet 32,
Gas is taken out from nozzles 4 and 5.

The strip coming out of the cover 29 is subjected to hot air drying treatment by a dryer 8 in a vertically advancing area, and is dried until the chemical conversion film does not adhere to the roll and peel off.

The deflector roll 2 and the strip are then turned around, completely dried again by the dryer 9, and then moved to the winding direction.

As the excess surface treatment solution for various Zn, AI, Sn, and plated steel strips and the blotting gas, air, nitrogen, and other gaseous substances, such as heated or non-heated gas such as water vapor, are used.

In this case, the use of heated gas reduces the drying process of the processing liquid after wiping.

In this invention, the spray nozzle for wiping is placed at least 10 cm away from the spray position, and the nozzle-strip interval is 5 cm on one side.
~5Qmm, the nozzle angle is O ~ 30', and the flow rate is 8 on one side from a nozzle with a slit interval of 0°4mm or more.
~30 Nm3/min and line speed 4Qm/m
Compressed gas for wiping is injected onto the strip-shaped plated steel sheet that is moving upward at a temperature of 1.5 in or more.

The nozzle slit has a slit gap in the range of 0.4 mm or more to about 3.2 mm, preferably 0.4 to 0.7 mm.

If the nozzle slit is 0.4 mm or less, nozzle clumping is likely to occur, which increases the number of times the nozzle is cleaned.

If the thickness is 3.2 mm or more, the splash will be severe and will adhere to the running plated steel strip, which will likely cause deterioration in appearance.

Although the nozzle-strip spacing varies depending on the processing purpose, it is usually 5 to 5 Qmm on one side.

If the thickness is less than 5mm, there is a risk that the plate surface will come into contact with the nozzle due to the shape of the strip-shaped plated steel plate to be threaded or warpage in the width direction.5Q
If it exceeds mm, the wiping effect will be drastically reduced.

The optimum range has been found to be a nozzle strip spacing of 15-20 mm.

Nozzle angle is 0-30°, preferably 3-5° downward
The range shall be .

If the angle is more than 30 degrees, the edges of the metal plate in the nozzles installed at approximately the same position on both sides of the strip-shaped plated steel plate tend to interfere with each other and cause nozzle fouling, which can cause product damage. It may become dirty.

For spraying, the gas flow rate is about 8 to 30 Nm37m1n on one side (over the entire surface).

If it is less than 8 Nm3/min, the wiping effect of the chromate treatment liquid is not so great, and if it is more than 3 ONm3/min, turbulence will occur due to the wiping gas, which is not preferable.

The optimum range was 10-15 m3/min.

The height of the bath surface of the wiping nozzle or the distance from the spray position is 10 cm or more, preferably about 20 to 40 cm.

If the nozzle height is less than 10 cm, the flow of the spray will be disturbed when the treatment liquid is spray coated by a downward branch of the wiping airflow, resulting in non-uniform adhesion of the treatment liquid.

The treatment solution that can be employed is, for example, a chromic acid-based or phosphoric acid-based chemical conversion treatment aqueous solution, or a water-soluble paint, a cleaning liquid, or an organic solvent solution containing a paint.

The concentration of the chromic acid solution can range from a fairly concentrated solution containing colloidal silica or a high-molecular organic compound to a dilute solution.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the device of the present invention, and FIG. 2 is an enlarged explanatory diagram of the clamping roll. 1...Zin roll, 2...Deflector roll, 3...Nozzle group, 4...
Gas nozzle, 5... Gas nozzle, 5...
・Roll, 7...Roll, 10...Water washing nozzle, 11...Nozzle for chemical treatment bath,
12... Nozzle for chemical treatment bath, 13...
...Nozzle for chemical treatment bath, 14...Valve,
15... Valve, 16... Valve, 1
7... Valve, 18... Valve, 19
...Valve, 20...Valve, 21.
... Valve, 22 ... Washing drainage tank,
23...tank, 24...tank, 2
5...Tank, 26...Pump, 27
...Pump, 28...Pump, 29.
...Cover, 30...Liquid saucer, 31...
····pump.

Claims (1)

[Scope of utility model registration request] A steel strip or a metal-plated steel strip is raised almost vertically,
A plurality of nozzles are arranged to supply a chemical conversion treatment liquid to the surface of the steel strip to be threaded, and each nozzle is connected to a plurality of tanks that store the chemical conversion treatment liquid. A nozzle for supplying cleaning water is arranged in the upper stage, and a wiping nozzle is placed above the nozzle group to wipe away excess liquid, and furthermore, to prevent the chemical conversion treatment liquid from scattering around the wiping nozzle and the chemical conversion treatment liquid supply nozzle group. In a device equipped with a cover for recovering chemical conversion treatment liquid, a flat roll is installed below the nozzle group that supplies chemical conversion treatment liquid, in contact with the steel strip, and temporarily stores the chemical conversion treatment liquid supplied from the nozzles on the surface of the steel strip. An apparatus for coating the surface of a steel strip or a metal-plated steel strip with a chemical conversion treatment liquid.