JPS595667B2 - Metal surface treatment equipment - Google Patents

Description

[Detailed description of the invention] The present invention relates to a metal surface treatment apparatus.

More specifically, for example, when pre-painting treatment, especially chemical conversion treatment, of a thin long metal used for coil painting is carried out by dipping, it is possible to control the dipping treatment time in response to changes in the conveyance speed of the metal. The present invention relates to an apparatus suitable for carrying out predetermined surface treatment. In coil coating, an appropriate metal conveyance speed is generally set depending on the chemical conversion treatment and other conditions such as coating.

In the same processing system, when processing metal plates with different thicknesses, it is generally adopted to change the metal transport speed. In such cases, in the case of chemical conversion treatment, the immersion treatment time itself must be adjusted in response to changes in the metal conveyance speed in order to achieve a specified surface treatment (that is, in many cases, to obtain a specified amount of chemical conversion coating). One way to deal with this is to independently control the changes. for example,
If the metal transport speed is faster than before, the dipping treatment time will be longer than before. A technique for this purpose is disclosed in Japanese Patent Publication No. 50-12380.

The disclosed apparatus uses one immersion treatment tank, and employs a structure in which metal is passed horizontally in a straight line through slits and grooves provided on the front and rear walls of the tank. The immersion treatment time is controlled as follows. (1) A movable partition plate is provided in the processing tank, a processing liquid is poured into one of the two chambers formed, and the immersion length of the metal is changed by moving the partition plate. (2) A plurality of fixed partition plates are provided in the processing tank to form a plurality of chambers, and the immersion length of the metal is changed by introducing and removing the processing liquid into the appropriate number of chambers. (3) A plurality of partition plates that can be raised and folded are provided in the processing tank, and the immersion length of the metal is changed by changing the number of foldable partition plates. (4) The treatment tank itself can be expanded and contracted in a telescopic manner, and the immersion length of the metal can be changed by the expansion and contraction.
Such processing equipment requires a large receiving tank to collect the processing liquid leaking to the outside through the slit in the processing tank. Moreover, it is necessary to provide not only the processing tank but also each partition plate with slits that can accommodate changes in the thickness of the metal plate, and special consideration must be given to sealing against the processing liquid. Furthermore, if the treatment liquid is a chemical conversion treatment liquid, there is a practical drawback that the movable parts cannot operate smoothly due to film formation or adhesion of generated sludge on the movable parts that come into direct contact with the treatment liquid. Note that a device in which a plurality of treatment tanks are arranged in series, slits are provided in the front and rear walls of each treatment tank, and metal is passed horizontally in a straight line through the slits to perform surface treatment is described in Japanese Patent Publication No. 43-402. Disclosed.

In this case as well, special consideration is required to install slits that can accommodate changes in metal plate thickness and to prevent leakage of processing liquid from the slits. Furthermore, there is no specific explanation about changing the immersion treatment time. Therefore, an object of the present invention is that, unlike the above-mentioned prior art, there is no need to worry about the leakage of the processing liquid from the processing tank, and the slits in the processing tank can be adjusted in response to changes in the thickness of the metal plate. The object of the present invention is to provide an improved and practical surface treatment device that does not require consideration of such considerations.

According to the present invention, (a) a processing tank group formed by arranging a plurality of processing tanks having different lengths in series in the length direction;
) Roll means disposed between adjacent processing tanks, in front of the first processing tank, and at the rear of the last processing tank, for guiding and supporting the thin plate-like long metal being transported above the liquid level of each processing tank. , (c) are placed at the front and rear of each processing tank, are supported so that they can be raised and lowered, are operated simultaneously in one processing tank, are located at a height that does not touch the metal when ascending, and are placed at a height that does not touch the metal when descending. (d) means for supplying the processing liquid to each processing tank, and (e) each processing tank. There is provided a metal surface treatment apparatus characterized by comprising means for taking out a treatment liquid.

Therefore, the metal being transported is subjected to immersion treatment by bending and guiding it downward, immersing it in the treatment liquid in the treatment tank, and then bending and guiding it upward and taking it out from the treatment liquid. When the immersion treatment is carried out by passing through the slits in the front and rear walls of the tank, there is no possibility of the problem of leakage of the treatment liquid from the slits to the outside.

Furthermore, since there is no need to change the manner in which the metal is immersed in the treatment liquid in response to changes in the thickness of the metal plate, there is no problem with the conventional technology in that it is necessary to install slits that can accommodate changes in the thickness of the metal plate. , there is no need to consider it in the present invention.
The immersion treatment time can be controlled by varying the length of contact between the metal and the treatment solution in each treatment tank, and by changing the number and/or position of treatment tanks where the metal and treatment solution do not come into contact (in other words, when multiple treatments are performed) Starting from using the entire tank for immersion treatment, using a part of the treatment tank for immersion treatment, and in this case, changing the number of treatment tanks used or/and changing the number of treatment tanks used from among the entire treatment tank. Since the immersion treatment time is appropriately selected, the immersion treatment time can be varied in a wide variety of ways compared to the total number of treatment tanks. That is, for example, one of the plurality of treatment tanks
When only the body is used for immersion treatment, the length of contact between the metal and the treatment liquid in each treatment tank is different as mentioned above, so it depends on which treatment tank to use out of the whole. All different immersion treatment times will be obtained (more specifically explained in the section relating to specific examples).
In order to make the contact length between the metal and the processing solution different in each processing tank, it is possible to use processing tanks of the same length and change the starting position of immersing the metal in the processing solution and the position of taking it out in each processing tank. . However, in this case, there is a processing tank having a length that is not used for the immersion process, which is disadvantageous in terms of the equipment. Therefore, it is advantageous to use treatment vessels having different lengths, thereby making the contact lengths different. To prevent contact between the metal and the processing solution, either do not bend the metal for immersion and maintain it in its original state during transportation, or remove the processing solution from the target processing tank and empty it. (This also includes preventing contact between the metal and the treatment liquid by lowering the liquid level in the treatment tank.)

The two may be combined to prevent contact between the metal and the processing liquid. Alternatively, the treatment liquid may be removed from the target treatment tank and water may be added thereinto to bring the metal into contact with the water. This is advantageous if it is not desired that the metal being immersed be in contact with the atmosphere for a long time. It is also advantageous in cases where it is not desirable for the treatment liquid to remain on the metal for a long time and for the reaction to proceed. Next, the present invention will be specifically explained with reference to FIG. In this device, the length ratio is 1:
Three processing tanks 1 with different lengths such as 2:4
, 2, and 3 are sequentially arranged in series in the length direction.

Each treatment tank may have a conventionally known shape such as a boat shape or a box shape, or it may have a shallow shape as long as it has a depth that allows the objects to be immersed in the treatment, or an overflow tank may be attached. You can leave it there. These tanks are connected to each other by connecting pipes with valves 4,
5 and 6, so that the height of the liquid level in the tank can be made the same. The thin plate-shaped long metal 7 is conveyed above each processing tank in the arrangement direction thereof, and is guided and supported by squeeze rolls 8, 9, 10, and 11 arranged before and after each processing tank. Receives its original function.
Relatively large-diameter dipping rolls 12a, 12b, 13a, 13b, 14a, and 14b are arranged at the front and rear parts of each processing tank. Each roll is supported from above by conventional means (for example, a cylinder) so that it can be raised and lowered,
12a and 12b, 13a and 13b and 14a and 14b
It is designed to move up and down at the same time. The upper limit of the upward movement of each roll is the height at which it does not come into contact with the metal 7 being transported, while the downward movement of each roll pushes the metal 7 down into the liquid in the processing tank and its own axis of rotation is located above the liquid level (i.e., The lower limit is the height (located at a height that does not come into contact with the processing liquid in the tank).
Therefore, during the immersion treatment, the metal is brought into satisfactory contact with the treatment liquid, but the movable parts (i.e., rotating shafts) of the immersion roll means 12a to 14b themselves do not come into contact with the treatment liquid.
Even during chemical conversion treatment, the movement of the relevant parts cannot be hindered. Each processing tank 1, 2, 3 is provided with valved supply pipes 15, 16, which are means for supplying processing liquid thereto.
, 17 are attached, and the other end of the tube is connected to a liquid tank 18.

Further, each treatment tank is provided with a valved discharge pipe 19, 20, 21, which is a means for taking out the treatment liquid therefrom, and the pipe is connected to the liquid tank 18 via a circulation pump 22. has been done. This treatment liquid circulation system is equipped with various means used in normal surface treatment, such as means for removing impurities in the treatment liquid (for example, sludge produced by chemical conversion treatment) and means for supplying replenishment liquid. It's okay to stay. These supply pipes and discharge pipes may be installed, for example, in the front part of each treatment tank, the latter in the rear part, or vice versa, if circulation of the treatment liquid in the tank is required. . Additionally, each treatment tank 1, 2, 3 is equipped with a valved supply pipe 23, 24, 25, which is a means for supplying water thereto.
The other end of the pipe is connected to the water tank 26, and has valved discharge pipes 27, 28, which are means for taking out water installed in each treatment tank.
29 may be connected to the water tank 26 via a circulation pump 30.

This water circulation system may also be provided with conventional means such as means for removing impurities from the water and means for supplying fresh water. In the apparatus configured as described above, when performing surface treatment using only the treatment tank 1, the treatment liquid is circulated and supplied to this treatment tank using the supply pipe 15 and the discharge pipe 19, and the immersion roll is 12a and 12b are lowered to bend and guide the metal 7 while immersing it.

Regarding the other processing tanks 2 and 3, (1) processing liquid is supplied in the same way as processing tank 1, but dipping rolls 13a and 13b
Then, 14a and 14b are raised to allow the metal 7 to pass through in its original conveyance state. Or (2) Processing tank 2
, 3 is drained to make it empty, and the dipping roll 13 is removed.
a and 13b and 14a and 14b may be lowered to bend and guide the metal 7, or the dipping roll may be moved as described above (
It may be increased in the same way as in 1). Alternatively, (3) water is circulated and supplied to the treatment tanks 2 and 3 using the supply pipes 24 and 25 and the discharge pipes 28 and 29, and the dipping rolls 13a and 13b and 14a and 14b are lowered to remove the metal 7 from the water. The treatment may be carried out while contacting with. Which of the above embodiments or a combination thereof is adopted for each of the treatment tanks 2 and 3 may be determined as appropriate depending on the purpose and conditions of the surface treatment. Even when surface treatment is performed using only treatment tank 2 or 3, it may be carried out in the same manner as described above.

When using two processing tanks 1 and 2, 1 and 3, or 2 and 3, or when using three processing tanks, it may be carried out in the same manner as described above.

In this case, it is advantageous to use the connecting pipes 4, 5, 6 to match the liquid level in each treatment tank. In this way, based on the contact length between the metal and the processing liquid in processing tank 1, it is twice as long in processing tank 2, three times as long in processing tanks 1+2, four times as long in processing tanks 3, and five times as long in processing tanks 1+3. , treatment tank 2+3
For example, 6 times for treatment tank 1+2+3, and 7 times for treatment tank 1+2+3.
Despite using a single treatment tank, it is possible to obtain seven different contact lengths between the metal and the treatment liquid.

In other words, when the metal transport speed is constant and does not change,
A wide variety of immersion times can be obtained by employing a small number of treatment tanks. This shows that even if the metal transport speed changes, the predetermined immersion time can be easily and accurately selected, which is very advantageous in terms of the apparatus. Next, an example of surface treatment using the apparatus shown in FIG. 1 will be explained.

Example 1 Processing tanks 1 and 2 are emptied, and dipping rolls 12a and 12b and 13a and 13b are raised.

The processing liquid is supplied to the processing tank 3, and the immersion rolls 14a and 14 are
b is lowered and the metal 7 is immersed. Metal: Plate thickness 0.
3511 hot-dip galvanized steel sheet treatment solution: Nippon Paint Co., Ltd. zinc phosphate coating chemical conversion treatment agent “Granogin 46N-23
'' used, total acidity 13, acid ratio 8, temperature 70°C Metal conveyance speed: 60 m/min Immersion treatment time: 10 seconds Example 2 The treatment liquid was supplied to treatment tanks 1 and 3, and immersion rolls 12a, 12b, and 14a were used. and 14b are lowered to immerse the metal 7.

The processing tank 2 is emptied and the dipping rolls 13a and 13b are raised. Metal: Same as Example 1 Treatment liquid: Nippon Paint Co., Ltd. zinc phosphate film conversion treatment agent “Granozin 46N-
35" used, total acidity 12, acid ratio 7.5, temperature 60°C Metal conveyance speed: Same as Example 1 Immersion treatment time: 12.5 seconds Example 3 Processing liquid in processing tanks 1 and 2, processing tank 3 Water is supplied to each of the wafers, and all the immersion rolls 12a to 14b are lowered to immerse the metal 7.

Metal: Same as Example 1 Treatment liquid: Same as Example 2 Metal Transport speed: Same as Example 1 Immersion treatment time: 7.5 seconds Example 4 The treatment liquid was supplied to all treatment tanks 1, 2, and 3. , all the dipping rolls 12a to 14b are lowered to perform dipping treatment on the metal 7.

Metal: Plate thickness 0.27m7! L hot-dip galvanized steel sheet treatment solution: Same as Example 1 Metal conveyance speed: 120 m/min Immersion treatment time: 8.8 seconds Example 5 The treatment solution was supplied to the treatment tanks 1 and 2, and the dipping rolls 12a and 12b were Then, 13a and 13b are lowered to immerse the metal 7.

The processing tank 3 is emptied and the dipping rolls 14a and 14b are raised. Metal: Hot-dip galvanized steel plate with a thickness of 0.6 mm. Treatment solution: Same as Example 2, except that the temperature was 70°C. Metal conveyance speed: 45 m/min. Immersion treatment time. The treated metals obtained in Examples 1 to 5 for 10 seconds or more are coated with an epoxy primer, then the front side is coated with a polyester paint, and the back side is coated with a melamine alkyd paint.

Table 1 shows the performance of the coated metal thus obtained.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a specific example of the device of the present invention,
, 2 and 3 are processing tanks, 4, 5 and 6 are connection pipes for liquid level adjustment, 7 is a metal plate, 8, 9, 10 and 11 are squeezing rolls, 1
2a to 14b are immersion rolls, 15, 16, 17 are processing liquid supply pipes, 19, 20, 21 are processing liquid extraction pipes, 23, 2
4 and 25 are water supply pipes, and 27, 28, and 29 are water outlet pipes.

Claims (1)

[Scope of Claims] 1. A metal surface treatment apparatus characterized by comprising the following configurations. (a) A treatment tank group consisting of a plurality of treatment tanks of different lengths arranged in series in the length direction, (b) Between adjacent treatment tanks, in front of the first treatment tank, and the last treatment tank (c) roll means arranged at the rear of each processing tank to guide and support the thin plate-like long metal being transported above the liquid level of each processing tank; They are operated at the same time in one processing tank, and when ascending, they are located at a height that does not touch the metal, and when descending, they are located at a height that pushes the metal down into the liquid in the processing tank, and the axis of rotation is above the liquid level. An immersion roll means located above, (d) means for supplying the processing liquid to each processing tank, and (e) means for taking out the processing liquid from each processing tank. 2. The device according to item 1 above, wherein the guide and support roll means (b) is a squeeze roll. 3. The apparatus according to item 1 or 2 above, which is provided with means for connecting the processing tanks to each other and making the liquid level heights therein match each other. 4. The apparatus according to any one of items 1 to 3 above, which is provided with means for supplying water to each treatment tank and means for taking it out. 5 The above-mentioned No. 1, wherein the treatment liquid is a zinc phosphate film chemical conversion treatment liquid.
The device according to any one of items 1 to 4.