JPH05339765A - Annealing method of aluminum bar - Google Patents

Abstract

(57) [Summary] [Purpose] Aluminum strips can be completely degreased, the surface characteristics in the width and length directions are highly uniform, and the annealing process can be carried out at low temperature and for short batch annealing. High productivity aluminum strip annealing method. [Structure] An aluminum strip annealing method of preliminarily degreasing by laser irradiation and then batch annealing in a process between a separator, a slitter, or a separator and a slitter and an aluminum strip winding machine.

Description

Detailed Description of the Invention

[0001]

The present invention relates to an aluminum strip after rolling (in the present invention, the aluminum strip has a thickness of 5 μm to 3 m).
m of aluminum or aluminum alloy foil or plate. ) Degreasing method, and more particularly to an aluminum strip annealing method having high productivity in the degreasing step of aluminum strips, which has high water wettability in the width direction and length direction of the strips and high uniformity of surface properties such as an oxide film.

[0002]

2. Description of the Related Art Aluminum is useful because it is excellent in workability and is a metal, and is supplied in large quantities at low cost as aluminum foil or plate-like material, and is used as packaging material, electrical material, industrial material, daily necessities. Widely used for decorations, most of them are annealed.

The purpose of annealing the aluminum strip is not only to soften the aluminum strip itself, but also to remove the rolling oil used in the production of the aluminum strip. Usually, it is better to soften the aluminum strip. For the purpose of removing the rolling oil in the latter case, the temperature, time, etc. of the annealing are set in practice.

In the annealing treatment, the rolling oil is removed at the same time as the annealing of the aluminum strip, but if the removal of the rolling oil is insufficient, many secondary processes such as a plastic film are carried out thereafter. Since it is likely to cause troubles in the steps of bonding with the like, printing, coloring, chemical treatment, etc., the annealing conditions are selected to completely remove the rolling oil rather than the softening conditions of the aluminum strip.

Regarding the removal of the rolling oil during the aluminum strip annealing process, the type of rolling oil becomes a problem as a factor affecting the processing temperature and time, and the width, winding diameter, winding hardness, etc. of the product have a great influence. give. Especially for aluminum strips, the demand for wide and long products has been increasing recently.
This is a direction to increase resistance to the loss of rolling oil from the coil, and heat treatment requires high temperature and long time to completely remove rolling oil, which is not necessarily desired. This is accompanied by softening of the aluminum strip.

Complete removal of rolling oil from the surface of the coil in the aluminum coil wound into a coil can be achieved to a considerable extent by subjecting the aluminum strip to the high temperature and long time heat treatment required for annealing. Often insufficient, the higher the temperature and the longer the heat treatment for the purpose of complete removal of rolling oil, the more the annealing of aluminum strips progresses,
The softening becomes inevitable. In addition to this, annealing of the product coil and sticking of streaks (stic
There are many problems to be solved in order to completely remove the rolling oil, such as k).

Thus, in order to completely remove the rolling oil and to ensure the uniformity of the surface characteristics in the width direction and the length direction of the coil (oxide film thickness, water wettability) by annealing in the coil shape as it is. , Heating at a temperature of about 300 ° C for a long time (for example, 5
It is said that it is necessary to process for 0 to 100 hours (Aluminium Foil Productio).
n. 1975, Vol. 20, pp185-207)
However, it is still difficult to obtain a product that is uniform in the width direction.

Especially in the case of rolling oil in the central part of the coil in the central part of the width of the coil of wide width and long product, it is lost from the place which is far from the outer surface and has a small clearance (when the winding hardness is hard). Long distance, less heat supply,
It becomes difficult to ensure the uniformity of the surface characteristics in the width direction due to the increased loss resistance, and it is necessary to anneal at a high temperature for a long time to ensure the uniformity, and it is necessary to further soften the aluminum strip. It will be promoted.

On the other hand, it is necessary to completely remove the rolling oil,
Rigidity is required for specific applications such as fields requiring highly rigid aluminum strips, such as PTP foils for pharmaceuticals, mini cups, etc., or applications such as cap sealing materials where printing pitch and misalignment are problems. High material (eg 30
03, Al-Fe alloy) is required, but if pure aluminum that has been coil-annealed for a long time is used, softening progresses and mechanical strength is remarkably lowered, causing various problems.

Therefore, it is not only difficult to completely remove the rolling oil in annealing the coil-wound aluminum strip (batch annealing in the present invention), but it also takes a long time to completely remove the rolling oil. However, the heat treatment is required, the oxide film becomes thick, and excessive annealing may be caused, which inevitably results in a decrease in productivity.

In some cases, the rolled aluminum strip is directly subjected to a slitter without undergoing an annealing step so as to have a uniform size and made into a hard strip product. In this case, volatile rolling oil is used to obtain a product without a removal step, or a treatment such as solvent degreasing is performed.

When the rolling oil removal process is not performed, a small amount of rolling oil adheres to the surface of the aluminum strip, and although it has rigidity as a hard strip, it is an obstacle to the processes such as printing and laminating. Causes the problem. On the other hand, those that have undergone processes such as solvent degreasing do not have the problem of rolling oil, but they require solvent degreasing treatment with a highly flammable organic solvent in a separate process, which not only increases costs but also deteriorates the working environment. Will be invited.

[0013]

The present invention is capable of completely degreasing the annealing process of an aluminum strip by batch annealing at a low temperature and for a short time, and the surface characteristics of the aluminum strip in the width direction and the length direction (oxidation). The purpose is to develop a degreasing method with high uniformity in film thickness and water wettability) and high productivity.

[0014]

Means for Solving the Problems The present invention is directed to a separator or slitter in the aluminum strip manufacturing process, or a step between the separator or slitter and the winder, in which the aluminum strip is preliminarily degreased with a laser and then batch-processed. The above object was achieved by developing an aluminum rolled strip annealing method characterized by performing an annealing treatment.

The aluminum strip which is the object of the present invention means pure aluminum for general industrial use (including electrolytic aluminum and ordinary pure aluminum) and aluminum alloy strip (hereinafter both aluminum strips unless otherwise specified). There is no particular limitation. The thickness of the aluminum strip is not particularly limited, but generally 5 μm
It is about 3.0 mm.

Laser treatment is a separator in the rolling process,
Where an aluminum strip such as a slitter is running on a single sheet, or during the process from the separator, slitter, etc. to the aluminum strip winder, especially in the case of a thin aluminum strip, a guide roll in the separator process,
It is preferable to perform the process in which a laser processing device is installed on a hard SL guide roll or the like.

As a laser processing device, a YAG (yttrium-aluminum-garnet with a small amount of neodymium) laser or carbon dioxide gas laser capable of high output is preferable, and either a pulse type or continuous beam generation is preferable. May be.

The beam from the laser generator may be irradiated by defocusing the width of the aluminum strip with a lens or a reflecting mirror. As a laser irradiation process, a separator or a slitter,
Alternatively, any step between them and the winding machine may be performed as long as it is before being wound into a coil and batch-annealed.

Prior to the laser treatment, the type of rolling oil adhered to the aluminum strip (oil absorption coefficient), the amount of rolling oil deposited, the aluminum material of the intended product aluminum strip, the mechanical strength, the strip thickness, Since the irradiation energy per area changes depending on the desired properties such as the contact angle of the aluminum strip with water, it is preferable to measure it experimentally. Since a small amount of preliminary degreasing may be required when sufficient annealing is required in the next annealing step, and sufficient rolling oil removal is required by preliminary degreasing when an aluminum strip with high mechanical strength is required. is there.

Generally, if the contact angle with water of the aluminum strip after irradiation is 30 ° to 80 °, it will be an aluminum strip having properties that will not hinder normal use simply by batch annealing. It is necessary to perform laser processing within this numerical range.

The aluminum strip preliminarily degreased by laser irradiation is then wound into a coil and sent to the batch annealing process. In the preliminary degreasing process, the contact angle with water is 30 ° ~
The 80 ° aluminum strip is treated in the batch annealing process according to the water wettability (S level: 30 ° or less, A level: 31 to 55 °, B level: 56 to 75 °, etc.) required as a product aluminum strip. It is necessary to set the temperature and processing time.

Since the aluminum strip coil according to the present invention has been preliminarily degreased by laser treatment in advance, the rolling oil to be removed is greatly reduced. The processing time can be mild.

This means that the annealing treatment of the product aluminum strip can be prioritized over the conditions required for removing the rolling oil, and the batch annealing conditions can be selected in consideration of the mechanical strength of the product aluminum strip. Generally, as this condition, an appropriate condition of 200 to 350 ° C. and 5 to 90 hours or less may be selected.

[0024]

The present invention shortens the time of batch annealing which requires a long time by preliminarily degreasing with a laser prior to batch annealing, and the surface characteristics of the aluminum strip in the width direction and the length direction (water wettability, This is to ensure the uniformity of the oxide film thickness).

In the preliminary degreasing in the method of the present invention, when one aluminum strip is running, the surface thereof is irradiated with laser light to degrease it. Therefore, the aluminum strip is heated to a high temperature in a coiled state. It has the advantage that it can be degreased very efficiently, as opposed to degreasing.

In the present invention, it is not necessary to completely degrease by preliminary degreasing, and annealing of aluminum strips (batch annealing)
Since further degreasing is carried out during this time, it is sufficient at this point to remove most of the rolling oil to be removed.

Since most of the rolling oil to be removed is thus removed, the rolling oil lost from the central portion of the coiled core during batch annealing is greatly reduced and its resistance is also reduced. It is thought that this enabled milder batch annealing conditions and shortened time.

[0028]

Example 1N30 aluminum foil having a separated gloss on one side, a thickness of 30 μm, a width of 600 mm and a length of 200 m was subjected to preliminary degreasing by defocusing the beam using an Nd: YAG laser. Next, at 240 ° C., annealing is performed in a coil shape, and the contact angle of the coil core and the central portion is 3
The final annealing time was 0 ° (a level that passed the S level in the pure water spray test). Further, the oxide film thickness in the width direction in the coil winding core portion after the final annealing was obtained. Table 1
Shows the laser treatment conditions, the contact angle after preliminary degreasing, the final annealing time, and the oxide film thickness after the final annealing.

[0029]

[Table 1]

The mechanical strength of the coils of Examples 1 to 4 after the batch annealing treatment was almost the same as the mechanical strength of the coils of the comparative example (without preliminary degreasing).

[0031]

EFFECT OF THE INVENTION The method for annealing an aluminum strip according to the present invention, in which pre-degreasing by a laser and then batch annealing treatment, has the following advantages. Since most of the rolling oil to be removed has been removed in advance, it is possible to shorten the processing conditions for batch annealing [reduction of temperature and processing time] (1/3 to 3/4). Preliminary degreasing is performed with one aluminum strip running, so even if batch annealing is performed, the surface properties (water wettability, oxide film thickness, etc.) in the width and length directions of the aluminum strip are uniform. It is possible to obtain high quality products. Preliminary degreasing makes it possible to adopt annealing conditions that match the mechanical strength required for product aluminum strips. Therefore, it has become possible to manufacture a completely degreased wide and long hard foil having high mechanical strength. Compared to the organic solvent degreasing method used as preliminary degreasing, it is not necessary to use highly flammable solvent,
The work environment was not contaminated by organic solvents, and a large-scale recovery device was not required, resulting in a large simplification of the device.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] July 17, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

[0029]

[Table 1]

Front page continued (72) Inventor Eizo Isoyama 6-224 Kaiyama-cho, Sakai City, Osaka Prefecture Showa Aluminum Co., Ltd. (72) Akio Fukuda 6-224 Kaiyama-cho, Sakai City, Osaka Prefecture In the company

Claims (2)

[Claims] 1. The aluminum strip is preliminarily degreased with a laser in a separator or a slitter in the aluminum strip manufacturing process, or a step between the separator or slitter and the winder, and then batch annealing treatment is performed. Aluminum rolling strip annealing method. 2. The contact angle between the surface of the aluminum strip and the pure water after the treatment is 30 ° -80 ° by performing the laser treatment.
After that, the aluminum rolled strip degreasing method according to claim 1, wherein batch treatment is performed at a temperature of 200 to 350 ° C. in a coil form.