JP3161391B2 - Lamination method of metal strip - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for laminating a resin film on a running metal strip, and more particularly to a method of laminating a metal strip for reducing bubbles trapped between the metal strip and the film.

[0002]

2. Description of the Related Art In recent years, a material obtained by laminating a resin film such as PET on the surface of a metal band such as iron or aluminum has been widely used as a material for cans. Laminating methods include a method using an adhesive and a method of heat-sealing a film.

FIG. 3 is a view showing a conventional heat fusion type laminating apparatus. The metal strip 1 is heated to an appropriate temperature by a heating device (induction heating, roll heating or the like is used) 6.
On the other hand, the film 2 is supplied to a laminating roll (hereinafter, referred to as a laminating roll) 3 via a guide roll 5, and in this process, the film may be preheated in some cases. Further, the film 2 is pressed against the metal band 1 by the lami roll 3 and is fused by the heat of the metal band 1. At this time, the surface temperature of the ramirole 3 also rises due to the heat from the metal strip 1, so that the surface temperature control device 4 cools the ramirole 3 to an appropriate temperature. A water-cooled roll is often used as the surface temperature adjusting device 4, and a flow rate of circulating water supplied to the water-cooled roll,
By controlling the temperature, the surface temperature of the Rami roll 3 can be maintained at an appropriate value. The pressing force of the lami-roll 3 is supplied by hydraulic pressure via a lami-roll bearing 8 as shown in FIG.

However, in both of the above-described method using an adhesive and the method of heat-sealing the film, air bubbles may remain between the metal strip and the film, and this is particularly noticeable during high-speed operation. .

[0005] It is considered that air bubbles are generated when air accompanying the running metal band and the film is brought into the rami roll press-fitting portion and sealed between the metal band and the film. In particular, when large bubbles are present, the film breaks and peels during can making. Therefore, even during high-speed operation, reducing air bubbles trapped between the metal strip and the film and increasing the adhesion of the film have been issues to be solved for improving productivity and quality.

There are the following methods for reducing the entrapment of air bubbles. JP-A-63-23382
In Japanese Patent Publication No. 4 (KOKAI) No. 4, a resin film is applied to a metal strip by 30 to 9 times.
There is disclosed a method in which the film is supplied at an angle of 0 degree and pressure-bonded by a ramirole.

Japanese Patent Application Laid-Open No. Hei 5-269857 discloses a method of removing air fluid itself which causes air bubbles by reducing the pressure in the vicinity of a lami roll press-fitting portion.

[0008]

However, it is understood that the film pressing method disclosed in Japanese Patent Application Laid-Open No. 63-233824 prevents the wedge effect of air fluid, but this method cannot be used alone at high speed operation. It is enough. Further, in the method of decompressing the vicinity of the pressure-bonded part of the lami-roll as disclosed in JP-A-5-269857 or the like, it is necessary to strengthen the degree of sealing (seal) between the decompressed part and the outside. It is not easy to do it. In addition, a vacuum pump for depressurization is required, and the operation cost is not negligible.

It is an object of the present invention to provide a method of laminating a metal strip which reduces bubbles trapped between the metal strip and the film even during high-speed operation in order to solve the above-mentioned problems. It is in.

[0010]

In order to solve the above problems and achieve the object, the present invention uses the following means. (1) In the method of the present invention, when a pressing force is applied to a pair of laminating rolls sandwiching a traveling metal band and a resin film is laminated on one or both sides of the metal band, the laminating roll pressing force: P (kg) ) Satisfies the following formula (1).

P ≧ 16 × 10 ⁻⁶ × WRV ^1.76 / πE (1) where P: laminating roll pressing force (kg), R: laminating roll radius (mm), V: transport speed of metal band (mpm) , E: Laminate roll contact Young's modulus (kg
/ Mm ² ), W: Laminate roll body length (mm), π:
Pi.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the conventional heat-sealing type laminating apparatus as shown in FIG. 3, the relationship between various operating conditions (especially the Lami roll pressing force and the Lami roll size) and the amount of bubbles generated has been relatively quantitative. No consideration has been given.

The present inventors have conducted various experimental studies to solve the problem of air bubble entrapment, and have obtained the following findings. In the conventional heat fusion type laminating apparatus shown in FIG. 3, the metal band transport speed V, the Rami roll pressing force P, the Rami roll radius R, and the bubble area ratio K (the ratio of the projected area of the bubble generating portion to the metal band surface area, the smaller the value, the smaller the value). When the relationship (the number of air bubbles was small and the adhesion of the film was good) was examined by experiments, the following findings were obtained.

(1) The greater the pressing force of the ramirole, the smaller the amount of bubbles generated. (2) The smaller the diameter of the ramirole, the smaller the amount of bubbles generated. Therefore, when the above experimental results were arranged by the nip surface pressure (Rami roll pressing force / contact area between metal band and Rami roll) p, the results shown in FIG. 2 were obtained. That is, by increasing the nip surface pressure, the generation of bubbles can be suppressed even during high-speed operation. It is well known that the nip surface pressure p is given by the following equation (2) from the Hertzian theory of elastic body contact.

P = 1/4 × (πEP / RW) ^1/2 (2) where p: Nip contact pressure (kg / mm ² ), P: Rami roll pressing force (kg), R: Rami roll radius (mm) ),
E: Rami roll contact Young's modulus (kg / mm ² ), W: Rami roll body length (mm), π: Pi. That is, according to the above equation (2), increasing the pressing force P of the ramirole and reducing the radius R of the ramirole lead to an increase in the nip surface pressure p, and thus the amount of generated bubbles can be reduced. It is. Next, regarding the data shown in FIG. 2, the nip surface pressure p for setting the bubble area ratio K to 3% or less, which does not cause a problem in product quality, is roughly:
6 kg / mm ² , p> 0.11k when V = 200 mpm
g / mm ² , p> 0.15 kg / when v = 300 mpm
mm ² , p> 0.19 kg / mm at V = 400 mpm
It turns out that it is about ² .

Based on this, FIG. 2 is rewritten in FIG. 2 to the relationship between the metal belt conveying speed V and the nip surface pressure p, where p is equal to or more than the value p _min given by the following equation (3). It can be seen that if there is, the bubble area ratio K can be suppressed to 3% or less. p _min = 0.001V ^0.88 (3) When the equation (3) is rearranged using the equation (2), the equation (1) is derived, and under this condition, the bubble area ratio K does not cause a problem in product quality. It can be suppressed to 3% or less. P ≧ 16 × 10 ⁻⁶ × WRV ^1.76 / πE (1) where, P: Lami roll pressing force (kg), R: Rami roll radius (mm), V: Metal belt transfer speed (mpm),
E: Rami roll contact Young's modulus (kg / mm ² ), W: Rami roll body length (mm), π: Pi. Based on the above findings, the present inventors increased the nip surface pressure and generated air bubbles when laminating a resin film on one or both sides of a traveling metal strip using a conventional heat fusion laminating apparatus. In order to reduce the pressing force of the laminating roll, the transport speed of the metal strip, the radius of the laminating roll, etc. are adjusted to be equal to or more than a certain value, so that it is simple and even during high-speed operation, the roll is caught between the metal strip and the film. The present inventors have found a method of laminating a metal strip for reducing bubbles to be generated, and have completed the present invention.

Hereinafter, embodiments of the present invention will be described. The method for laminating a metal strip according to the present invention is described in, for example, FIG.
When the running metal band 1 is sandwiched between a pair of Rami rolls 3 by using a heat fusion type laminating apparatus as shown in FIG. 1 and the resin film 2 is continuously laminated on one side or both sides of the metal band 1, the Lami roll pressing force is applied. : P (kg) is the following (1)
It is characterized by satisfying the expression.

P ≧ 16 × 10 ⁻⁶ × WRV ^1.76 / πE (1) where, P: Lami roll pressing force (kg), R: Rami roll radius (mm), V: metal belt conveyance speed (mpm),
E: Rami roll contact Young's modulus (kg / mm ² ), W: Rami roll body length (mm), π: Pi. The above equation (1) is based on the experimental results that the generation of bubbles can be suppressed even during high-speed operation by increasing the nip surface pressure, as described above. It is derived. Here, the reason why the lami-roll pressing force P is set to be equal to or more than the value given by the above equation (1) is that the bubble area ratio K is set to 3% which does not cause a problem in product quality.
This is for suppressing the following. Hereinafter, examples of the present invention will be described to demonstrate the effects of the present invention.

[0019]

EXAMPLE Using a metal strip laminator shown in FIG. 3, a 20 μm thick PET film (having a melting point of about 230 mm) was coated on one side of a steel strip having a thickness of 0.24 mm and a width of 1017 mm.
° C) with the operating conditions (No. 1-3, 2-3:
Example of the present invention, 1-1, 1-2, 2-1 and 2-2: Comparative Example) to produce a laminated metal band, and the bubble area ratio K was examined. Table 1 also shows the survey results.

The used Rami roll is made of steel and has a structure in which the surface is covered with hard rubber. The body length (W) is 1400 mm and the contact Young's modulus (E) is 2.4 k.
g / mm ² .

As shown in Table 1, Example No. of the present invention in which the nip surface pressure p is within the range of the present invention (p ≧ p _min , that is, the pressing force P of the formula (1) is within the range of the present invention) . 1-
In all of the samples 3, 2-3, the bubble area ratio K is reduced to 3% or less.

On the other hand, when the nip surface pressure p is out of the range of the present invention (p
Comparative Example No. <p _min , that is, the Ramiroll pressing force P in the formula (1) is out of the range of the present invention). 1-1, 1-2, 2-
In Nos. 1 and 2-2, the bubble area ratio K exceeds 3%, and the reduction of the bubble entrainment amount is not sufficient. From the above, it can be seen that by satisfying the above-described formula (1) of the present invention, bubbles can be reduced to a certain level or less.

[0023]

[Table 1]

[0024]

As described above, according to the present invention,
By specifying the pressing force on the laminating roll, it is possible to provide a method of laminating a metal strip that is simple and reduces bubbles generated between the metal strip and the film even during high-speed operation.

[Brief description of the drawings]

FIG. 1 is a diagram showing a relationship between a metal band conveyance speed and a nip surface pressure, which affects product quality.

FIG. 2 is a diagram showing the influence of the metal band transport speed and the nip surface pressure on the bubble area ratio.

FIG. 3 is a diagram showing a schematic configuration of a conventional heat fusion type metal band laminating apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal band, 2 ... Resin film, 3 ... Rami roll, 4 ...
Surface temperature control device, 5: Guide roll, 6: Metal strip heating device, 7: Top (turn) roll, 8: Lami roll bearing.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toyoka Teramoto 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan Co., Ltd. (72) Inventor Sadaka Masuda 1-1-2 Marunouchi, Chiyoda-ku, Tokyo Nippon Kokan (56) References JP-A-6-8336 (JP, A) JP-A-8-238715 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 15/08

Claims (1)

(57) [Claims] When a pressing force is applied to a pair of laminating rolls sandwiching a traveling metal band to laminate a resin film on one or both sides of the metal band, the laminating roll pressing force: P (kg) is as follows: 1) A method for laminating a metal strip, characterized by satisfying the following expression: P ≧ 16 × 10 ⁻⁶ × WRV ^1.76 / πE (1) where P: laminating roll pressing force (kg), R: laminating roll radius (mm), V: transport speed of metal band (mpm), E: Laminate roll contact Young's modulus (kg
/ Mm ² ), W: Laminate roll body length (mm), π:
Pi.