JP2001276713A - Method and apparatus for manufacturing web - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and apparatus for manufacturing a web, suppressing the bending and vibration of a metering bar though the diameter of the metering bar is 30 mm or less and preventing the generation of the passing through of a coating solution or a bar streak. SOLUTION: In the method and apparatus for manufacturing the web, coating the surface of the running web W with the coating solution A and leveling the coating solution by the metering bar 2 to obtain the web having a coating film uniform in thickness, the diameter D (mm) of the metering bar 2 is set to 30 mm or less and the metering bar is supported by a plurality of support parts 3 arranged intermittently in the length direction of the metering bar 2 and the interval L (mm) of the adjacent support parts 3 is set to L<=30×D to set the bending quantity of the metering bar during coating treatment to 0.2 mm or less and the vibration amplitude thereof in an orthogonal direction to 0.2 mm or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a web for applying a coating solution to the surface of a web at a uniform thickness, and more particularly, to applying a coating solution at a high speed so as to prevent uneven coating on the surface. The present invention relates to a method and an apparatus for producing a thermoplastic resin film.

[0002]

2. Description of the Related Art In general, a metaling bar method is often used to apply a coating solution to a surface of a web such as a thermoplastic resin film to a predetermined uniform thickness. With this metaling bar method, after a coating liquid is excessively applied to the surface of the running web, a part of the coating liquid is scraped off by contacting a metal metering bar with the surface of the excess coating liquid. And to form a uniform coating film having a predetermined thickness.

However, since the coating width in the width direction of the web is considerably larger than the diameter of the metalling bar, the metalling bar is bent by the running tension of the web and the weight of the metaling bar itself. When such bending occurs in the metalling bar, the coating liquid passes through at the bent portion, so that a coating film having a uniform thickness in the width direction of the web cannot be formed.

Further, when the web is run at high speed, the metalling bar vibrates. In particular, due to the vibration in the direction perpendicular to the metalling bar, the coating liquid repeatedly generates thick and thin portions at substantially equal intervals. Become. A coating defect called a so-called barge occurs.

Heretofore, as a countermeasure for solving the above-mentioned drawbacks of the coating liquid slip-through and the burs, the diameter of the metering bar has been increased to a diameter exceeding 30 mm. However, as the diameter of the metering bar is increased, the metering portion becomes excessively large, thereby causing a problem that the handling of the apparatus and the maintenance and inspection become complicated.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to overcome the disadvantages of the prior art and to reduce the diameter of the metering bar by 30.
It is an object of the present invention to provide a method and an apparatus for manufacturing a web capable of applying a coating liquid at a high speed and with a uniform thickness while suppressing deflection and vibration while preventing the coating liquid from slipping through the coating liquid and preventing occurrence of a bursee.

[0007]

According to the present invention, there is provided a method for producing a web, comprising applying a coating solution to the surface of a running web, and scraping the coating solution with a metering bar to obtain a uniform thickness. In a method for producing a web having a coated film, the diameter D (mm) of the metalling bar is set to 30 mm or less, and the metal ring bar is circumscribed and supported by a plurality of support portions intermittently arranged in the length direction. By setting the distance L (mm) between the supporting parts adjacent to each other as L ≦ 30 × D,
The bending amount of the metering bar during the coating process is 0.2 mm or less,
In addition, the vibration amplitude in the orthogonal direction is set to 0.2 mm or less.

Further, the web manufacturing apparatus of the present invention for implementing the above method applies a coating solution to the surface of a running web,
In a web producing apparatus in which the coating liquid is stirred with a metaling bar to form a web having a coating film of a uniform thickness, the metalling bar has a diameter D (mm) of 30 mm or less and a length of 30 mm or less. The distance L (mm) between the supporting parts which are circumscribed by a plurality of supporting parts intermittently arranged in the vertical direction and which are adjacent to each other is L ≦ 30 × D.

As described above, the diameter D of the metering bar is 30.
mm or less, but the metalling bar is circumscribed and supported by arranging a plurality of support portions intermittently in the length direction, and the interval L (mm) between the support portions is set to an interval of L ≦ 30 × D. In addition, the bending of the metalling bar can be suppressed to an allowable range of 0.2 mm or less and the vibration amplitude can be suppressed to 0.2 mm or less, and the occurrence of slippage of the coating liquid and bursiness can be eliminated.

[0010] In another production method of the present invention, a coating liquid is applied to the surface of a running web, and the coating liquid is raked with a metaling bar to form a web having a coating film with a uniform thickness. In the manufacturing method, the diameter D of the metalling bar is set to 30.
mm or less, and by circumscribing the support by a support that extends continuously in parallel with the length direction, the bending amount of the metalling bar during the coating process is 0.2 mm or less, and the vibration amplitude in the orthogonal direction Is set to 0.2 mm or less.

Further, in the manufacturing apparatus of the present invention for carrying out the above method, a coating liquid is applied to the surface of a running web, and the coating liquid is raked with a metaling bar to form a coating film having a uniform thickness. In the web manufacturing apparatus for forming a web, the metalling bar has a diameter D of 30 mm or less, and is circumscribed by a supporting portion that extends continuously in parallel with the length direction. Things.

Thus, the diameter D of the metering bar is 30
mm or less, but since the metalling bar is circumscribed by a supporting portion that extends continuously in parallel to the length direction, the bending of the metalling bar is 0.2 mm or less, and the vibration amplitude is 0.2 mm or less. It can be suppressed to an allowable range, and the occurrence of coating liquid slip-through and burs can be eliminated.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a web means a sheet-like material such as a thermoplastic resin film, paper, leather, non-woven fabric, knitted fabric and the like. In particular, it can be suitably applied to a thermoplastic resin film.

The present invention is to produce a web in which a coating solution is applied to at least one surface of the web to a uniform thickness. First, the coating solution is applied to the surface of the web in a slightly excessive amount than a prescribed application amount. Then, the applied coating liquid is then coated with a diameter D
Is to scrape off only the excess coating liquid using a small diameter metalling bar of 30 mm or less to form a coating film having a predetermined uniform thickness.

In the present invention, when the coating liquid is scraped off using a small diameter metalling bar as described above, the first method is to intermittently dispose the metalling bar in the length direction. A plurality of supporting portions are circumscribed and the distance L (mm) between adjacent supporting portions is determined by the diameter D of the metalling bar.
(Mm) is set to L ≦ 30 × D.

In another method, the metering bar is circumscribed and supported by a support portion that extends continuously in parallel with the length direction.

By supporting the metalling bar in this manner, the bending amount of the metalling bar during the coating process of the coating liquid is 0.2 mm or less and the vibration amplitude in the orthogonal direction is 0.2 mm.
The tolerance can be suppressed to an allowable range of not more than mm, and it is possible to eliminate a coating liquid slippage caused by bending of the metalling bar and a bursee caused by vibration of the metalling bar.

FIG. 1 and FIG. 2 schematically show an example of an apparatus for producing a thermoplastic resin film as a web.

The web (thermoplastic resin film) W travels substantially horizontally in the direction of the arrow with a tension higher than a predetermined tension, and a coating nozzle 1 and a metalling bar are provided on the lower surface of the web W along the travel direction. 2 extend in the width direction so as to traverse the web W. Of these, the metalling bar 2 rotates in the same direction as the running direction of the web W, and its lower surface is circumscribed by a plurality of support portions 3 intermittently arranged in the longitudinal direction. The plurality of support portions 3 are arranged such that the distance L (center-to-center distance) between adjacent support portions is L with respect to the diameter D of the metalling bar 2.
(Mm) ≦ 30 × D (mm).

Each support portion 3 has a pair of left and right support rollers 4,
4 and a coating liquid intrusion prevention cover 5. And,
The plurality of supports 3 are fixed on a common base 6. In each support portion 3, a pair of left and right support rollers 4,
Numeral 4 makes the rotation axis parallel to the axial direction of the metering bar 2 and supports the lower surface side of the outer peripheral surface of the metering bar 2 from the left and right. The coating liquid intrusion prevention cover 5 covers the support roller 4 so as to prevent the coating liquid A from scattering and also covers the metalling bar 2 so that only the upper surface protrudes.

In the above configuration, while the web W travels in the direction of the arrow, the coating liquid A is applied slightly on the lower surface side by the coating nozzle 1 and then the excess coating liquid Aa is scraped off by the metaling bar 2. Then, the remaining coating liquid Ab is formed into a coating film having a uniform thickness.

In the present invention, the metalling bar is disposed close to and parallel to the surface of the web, so that a surplus portion is scraped off so that the coating solution applied to the web surface has a uniform thickness (metalling bar). )I do. A small diameter steel shaft having a diameter of 30 mm or less is used for the metalling bar, and a steel shaft having a diameter of 3 to 30 mm is preferably used. The structure of the metering bar is not particularly limited as long as it is straight and straight. However, in order to improve the weighing function, preferably, a thin wire having a diameter of 0.01 to 1 mm is densely spirally wound around the outer periphery, or a depth of 0.001 to 0.1 mm and a pitch of 0 to the outer periphery. It is preferable to use one provided with a spiral groove of 0.01 to 0.1 mm.

FIG. 3 illustrates a metaling bar around which the above-mentioned wire is wound.

A wire 2a is provided on the outer peripheral surface of the metering bar 2.
Are densely wound spirally, and a hard metal plating layer 2b such as chrome is provided on the outer surface of the wire 2a. The plating layer 2b can improve the wear resistance of the metalling bar and extend the life. The hard metal plating layer may be a metal deposition layer or a metal sprayed layer instead of the plating layer.

During the coating process, the metering bar may be rotated or fixed. However, it is preferable to rotate the web in the same direction as the running direction of the web so as not to generate scratches on the web surface. For a web that is not a problem for a small amount of scratches, the rotation direction of the metering bar may be reverse to the running direction of the web, or may be fixed.

When the metalling bar is rotated in the same direction as the running direction of the web, the peripheral speed is determined by the conditions of the coating liquid such as the viscosity and temperature of the coating liquid, the running speed of the web, and the conditions of the object to be coated such as the surface roughness. Although it is affected by coating conditions such as coating accuracy and the like, it is preferable to set it in a range of −10% to + 10% of the running speed of the web.

If the metalling bar is rotated in the same direction as the running direction of the web in such a peripheral speed range, the difference in the relative speed between the metalling bar and the web becomes small, so that not only scratches are not generated on the web, but also In addition, the wire wound around the outer periphery of the metalling bar can be prevented from being broken, and the metalling bar can be prevented from being worn. Here, the same direction refers to the rotation direction of the metalling bar with respect to the web at the contact point between the metaling bar and the web. The rotation of the metering bar may be free rotation or positive drive rotation as long as the rotation is within the above speed range.

In the example shown in FIGS. 1 and 2,
The support roller 4 is illustrated as an example, but as shown in FIG.
The fixed block 14 may be a pair of left and right inclined surfaces 14a, 14a formed in a V-shape, and the inclined surfaces 14a, 14a circumscribe the lower surface of the outer periphery of the metalling bar 2. The support roller 4 and the fixed block 14 prevent the metalling bar 2 from deforming in a direction opposite to the web W due to the pressing force from the web W and the weight of the metalling bar 2 itself. These axes are parallel to the axis of the metering bar 2.

The material of the support roller 4 is not particularly limited, but preferably uses an elastic resin such as urethane.
Further, it is preferable to reduce the rotational friction by incorporating a bearing or the like into the shaft portion, and it is particularly preferable to provide a ceramic bearing. On the other hand, the material of the fixing block may be steel or resin. If it is made of steel,
It is preferable that the V-shaped inclined surface supporting the metalling bar is coated with a fluororesin and subjected to easy lubrication to reduce frictional resistance.

When the plurality of support portions 3 are intermittently arranged in the longitudinal direction of the metalling bar 2, as described above, the bending generated in the metalling bar 2 during the coating process is 0.2 mm or less, and the vibration amplitude is Is required to be within the allowable range of 0.2 mm or less, the distance L between centers between adjacent supporting portions needs to be L (mm) ≦ 30 × D (mm) with respect to the diameter D of the metalling bar 2. .

More preferably, the difference between the heights of the support surfaces on which the adjacent support portions 3 support the metering bar 2 is 0.1 mm.
It is better to: The method for measuring the difference in the height of the support surface of the support portion 3 is not particularly limited. For example, as shown in FIG. 6, a dummy metering bar 12 is placed on two adjacent support portions 3 and 3. Digital inclinometer 13 above
(For example, AngleStar Digital Protrac manufactured by Lucas, USA)
tor DP-45), and can be measured from the measured value of the inclinometer 13.

In the embodiment described above, the plurality of support portions 3 are intermittently arranged discontinuously along the metalling bar 2. A single continuous support portion over the entire length may be used to support the left and right sides of the outer peripheral lower surface. In this case, as in the case of the plurality of support portions,
Deflection of the metalling bar 2 during the coating process is 0.2 mm
In addition, the vibration amplitude can be suppressed to an allowable range of 0.2 mm or less.

Regardless of whether the supporting portion is arranged discontinuously or continuously, the supporting portion 3 is further subjected to a coating process in order to suppress the vibration amplitude of the metalling bar 2 to an allowable range of 0.2 mm or less. Is preferably set to 0.1 mm or less. When the vibration amplitude is 0.1 mm or less, the frequency of the vibration has no dependency, so that the effects of the present invention can be obtained regardless of the frequency distribution. However, as the frequency distribution, it is desirable to reduce low frequency components of preferably 1 to 10 Hz.

It is preferable that the vibration to be suppressed is reduced in all directions. However, the amplitude specified in the present invention needs to be applied particularly to the vibration in the direction perpendicular to the metaling bar. The method of measuring the amplitude may be an actually measured value or a calculated value calculated from the acceleration. Generally, those calculated from acceleration measured by a piezoelectric vibrometer are often used. Any vibration meter for measuring acceleration may be used. For example, "Machine Analyzer MK-" manufactured by "Kawatetsu Advantech"
For example, "500" may be used.

It is desirable to measure the bending of the metaling bar during the coating process during the running of the web. However, the deflection is not limited to the running as long as the same bending as during the running of the web can be reproduced. As a method of measuring the bending of the metering bar while the web is running, a method of measuring the deflection by moving the laser displacement meter horizontally is generally used.

When measuring while the web is stopped, it is necessary to reproduce the deflection caused by the tension of the web. That is, a temporary web is hung on a metering bar, and the same tension as during the running of the web is applied, and the bending is reproduced as shown in FIG. 5 to obtain a digital inclinometer (Lucas AngleStar Digit, USA).
tal Protractor DP-45).

[0037]

Examples 1 and 2 and Comparative Examples 1 and 2 By using the apparatus shown in FIGS. 1 and 2, a web was prepared by applying a low-melting polyester aqueous solution (coating liquid) having a viscosity of 12 cp to a polyester film having a width of 1000 mm. In doing so, the diameter D of the metalling bar, the difference e between the heights of the support portions, and the distance L between the support portions were made different from each other as shown in Table 1 to produce a web to which the coating liquid was applied (Examples 1 and 2). Example 2, Comparative Example 1, Comparative Example 2).

Table 1 shows the results of measuring the bending amount and the amplitude of the metalling bar and the results of changing the coating speed and the coating thickness in each case.

The meanings of x, Δ and ○ shown in “coating speed” and “coating thickness” in Table 1 are as follows.

×: Slippage of the coating liquid or / and occurrence of a berth in full width △: Partially generated bursie ○: Neither slippage of the coating liquid nor bursage occurred

[0041]

[Table 1]

As is clear from Table 1, in Examples 1 and 2 satisfying the conditions of the present invention, even if the coating speed is as high as 70 m / min or more and the coating thickness is 30 μm or less, It can be seen that there is no coating liquid slip-through or drawback defect, and a good product can be obtained.

[0043]

As described above, according to the present invention, the bending and vibration of the metalling bar can be suppressed to within an allowable range of 0.2 mm or less while the diameter of the metaling bar is reduced to 30 mm or less. Even when the coating treatment is performed at a high speed, defects such as slippage of the coating liquid and burs can be prevented, and a high-quality web can be obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an apparatus for performing a web manufacturing method of the present invention.

FIG. 2 is a longitudinal sectional view of a main part in the apparatus of FIG.

FIG. 3 is a longitudinal sectional view showing an example of a metaling bar used in the present invention.

FIG. 4 is a longitudinal sectional view showing another example of a portion where a metering bar is installed in an apparatus for performing the web manufacturing method of the present invention.

FIG. 5 is a schematic diagram illustrating bending of a metaling bar.

FIG. 6 is an explanatory diagram of a method for measuring a difference in height of a support portion in an apparatus for performing the web manufacturing method of the present invention.

[Description of Signs] 1 Coating nozzle 2 Metalling bar 3 Support section 4 Support roll 6 Base A Coating liquid W Web

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yusaku Nakagawa 1-1-1 Sonoyama, Otsu-shi, Shiga F-term in the Shiga Plant of Toray Industries Co., Ltd. 4D075 AC53 DA04 4F042 AA22 DD09 DD16

Claims (13)

[Claims] 1. A coating liquid is applied to the surface of a running web,
In a method for producing a web having a coating film of a uniform thickness by scraping the coating liquid with a metaling bar, the diameter D (mm) of the metalling bar is reduced to 30 mm or less, and the length of the metalling bar is reduced to 30 mm or less. Circumscribed by a plurality of support parts intermittently arranged in the direction, and the distance between adjacent support parts L (mm)
Is set to L ≦ 30 × D so that the bending amount of the metalling bar during the coating treatment is 0.2 mm or less and the vibration amplitude in the orthogonal direction is 0.2 mm or less. 2. The method for producing a web according to claim 1, wherein a difference between support heights of the adjacent support portions is set to 0.1 mm or less. 3. A coating solution is applied to the surface of a running web,
In a method for producing a web having a coating film with a uniform thickness by scraping the coating liquid with a metaling bar, the diameter D of the metalling bar is set to 30 mm or less, and the diameter D of the metalling bar is parallel to the length direction. Circumscribed by a supporting portion that extends continuously to the outside, so that the bending amount of the metalling bar during the coating process is 0.2 mm or less, and the vibration amplitude in the orthogonal direction is 0.2 mm.
A method for producing a web with a thickness of less than mm. 4. The method for producing a web according to claim 1, wherein the vibration amplitude of the support portion is set to 0.1 mm or less. 5. The support portion comprises a pair of left and right support rollers whose axial direction is parallel to the metering bar.
5. The method for producing a web according to any one of 4. 6. The method for producing a web according to claim 1, wherein the supporting portion comprises a fixed block that circumscribes and supports the metering bar with a pair of left and right inclined surfaces. 7. The method for producing a web according to claim 1, wherein the web is a thermoplastic resin film. 8. A coating solution is applied to the surface of a running web,
In a web producing apparatus in which the coating liquid is stirred with a metaling bar to form a web having a coating film of a uniform thickness, the metalling bar has a diameter D (mm) of 30 mm or less and a length of 30 mm or less. An apparatus for manufacturing a web, which is circumscribed by a plurality of support portions intermittently arranged in a vertical direction and in which a distance L (mm) between adjacent support portions is L ≦ 30 × D. 9. The web manufacturing apparatus according to claim 8, wherein the difference between the heights of the support surfaces of the adjacent support portions is 0.1 mm or less. 10. A web manufacturing apparatus for applying a coating liquid to the surface of a running web and scraping the coating liquid with a metaling bar to form a web having a coating film having a uniform thickness.
An apparatus for manufacturing a web, wherein the metalling bar has a diameter D of 30 mm or less and is circumscribed and supported by a supporting portion that extends continuously in parallel with the length direction thereof. 11. The web manufacturing apparatus according to claim 8, wherein the vibration amplitude of the support portion is 0.1 mm or less. 12. The method according to claim 8, wherein the metalling bar has a configuration in which a linear body is spirally wound around the outer periphery of the cylindrical rod, and the outer periphery of the linear body is metal-plated. Web manufacturing equipment. 13. The web manufacturing apparatus according to claim 8, wherein the web is a thermoplastic resin film.