JPH01315363A - Device for method for washing backing roll - Google Patents

Abstract

PURPOSE:To inhibit the contamination of a washing doctor causing the spread of water on a backing roll by arranging edge washing tools at both side parts of the backing roll above a washing shower. CONSTITUTION:A washing shower 7 and a washing doctor 6 are fitted over the full width of the surface of a backing roll 1 having a metering mechanism and edge washing tools 8 are arranged at both side parts of the roll 1 above the shower 7. Brushes capable of feeding washing water are used as the tools 8. The contamination of the washing doctor causing the spread of water on the backing roll can be inhibited within the limits of the possible.

Description

DETAILED DESCRIPTION OF THE INVENTION [A] Field of Industrial Application The present invention relates to an apparatus and method for cleaning a backing roll of an apparatus for applying a coating liquid to a coating material such as paper or plastic film.

[B] Conventional technology In general, coating equipment for producing coated paper transfers more coating liquid than the required coating group, and uses a metering device such as a blade to scrape off the excess coating liquid. will be constructed. At that time, the coating liquid is transferred to a width greater than the paper width, and the coating liquid transferred to the paper and the coating liquid transferred to the backing roll are scraped off, but it is difficult to completely scrape off, and unless this is washed, Problems such as drying and staining the coated paper and dry coating fluid making metaling difficult occur. For this reason, the coating equipment is equipped with a backing roll cleaning device. This backing roll cleaning device has a structure in which cleaning shower water is flowed inside a cleaning doctor set diagonally so that the tip is pressed against the backing roll to rinse away the coating liquid.

The causes of stains on the surface of the backing roll in the above-mentioned coating device are as follows.

(b) If the wear is porous such as paper, dirt penetrates the wear and reaches the backing roll during coating; (b) dirt is caused by foreign matter on the wear surface; (c) for double-sided coated T products, the coated surface is backing. There is peeling of the coating layer during the pre-coating process when it comes into contact with the roll, and (ii) coating liquid adhering to the edges on both sides where there is no wear.

As a method for cleaning such dirt on the backing roll, use the method described in (a) 1. Conventional backing roll cleaning doctors and cleaning showers are sufficient to clean stains (b) and (c), and due to the relatively low coating liquid concentration, coating speed, and required coated paper quality, If a coating liquid with higher stability can be used, the stain (d) can be cleaned without any particular problem.

[C] Problems to be Solved by the Invention However, due to the recent increase in the speed of coating machines, the demand for higher operating efficiency, and the decline in the stability of coating fluids due to the demand for higher quality, (d) The problem of dirt has come into close focus.

Dirt on the edges of the backing roll caused by the coating liquid on both sides of the backing roll where there is no wear is mixed and diluted by supplying a large amount of cleaning shower water and scraped off by a cleaning doctor, but the backing roll cleaning The adhesive scum generated in the device is removed by diluting the coating liquid transferred onto the backing roll (1) at the contact point between the tip of the cleaning doctor (6) and the backing roll (1) with the cleaning shower water. In the process of being exposed to large shearing forces,
This dirt, which is generated when adhesives, especially polymeric latex, aggregate and form a film, accumulates on the cleaning doctor and lifts the cleaning doctor, creating a gap between the cleaning doctor and the backing roll, causing the doctor cleaning shower water to This can lead to accidents involving water. If water leakage occurs, the web before coating will be soiled or broken, making it impossible to continue coating any longer.If water leakage occurs to some extent around the edge of the cleaning doctor, the cleaning doctor must be replaced, reducing work efficiency. It will drop.

As a result of intensive studies, the present invention was developed with the aim of suppressing as much as possible the occurrence of stains on the cleaning doctor, which causes water around the backing roll.The present invention was developed by selectively cleaning stains on the edge of the backing roll before the cleaning doctor. However, the present invention has been achieved in which the cleaning load on a part of the cleaning doctor is reduced.

[D] Means to solve the problem The cause of stains on the conventional cleaning doctor edge is that the high concentration coating liquid transferred to the backing roll and the edge is diluted to a certain concentration with cleaning water, and then The reason is that the degree of dilution is not sufficient to maintain the stability of the coating fluid. If the diluted coating liquid enters the cleaning doctor in this state, it loses stability when it is scraped off by the doctor, resulting in coagulation of latex and staining.

Experiments to date have shown that if the high-concentration coating liquid on the backing roll edge is diluted in advance to a problem-free state, stains on the cleaning doctor edge are less likely to occur. An edge cleaning tool was provided in the area where the coating liquid was transferred.

That is, the present invention provides a coating device that includes a metering section, an applicate section, and a backing roll section. This is a backing roll cleaning device in which a shower is installed and edge cleaning tools are installed on both sides of the backing roll above the cleaning shower, and the coating liquid transferred to the backing roll edge is selected using the backing roll cleaning device. This is a backing roll cleaning method that cleans the backing roll.

[E] Effect: An edge cleaning tool that selectively dilutes and cleans the high 9 degree coating liquid is installed at the edge of the backing roll in front of the existing cleaning doctor to reduce the cleaning load on the cleaning dofter. It is possible to prevent the occurrence of dirt.

[Fco Example Embodiments of the present invention will be described based on the drawings.

Embodiment 1 FIG. 1 is a schematic side view of a backing roll cleaning device showing one embodiment of the present invention, and FIG. 2 is a schematic front view of FIG. 1.

In the figure, 1 represents a backing roll, 2 an applicator roll, and 3 a coating liquid groove color pan for supplying a coating liquid to the applicator roll 2, which is provided below the backing roll 1. 4 is a blade for scraping off the excess coating liquid applied to the surface of the wear 5 to a required amount. Reference numeral 6 denotes a cleaning doctor for scraping off dirt substances adhering to one surface of the backing roll, 7 a cleaning shower for cleaning the cleaning doctor, and 8 a cleaning of the edges on both sides of the backing roll 1, which is a feature of the present invention. Represents an edge cleaning tool for cleaning.

FIG. 3 is a schematic diagram showing a brush-type edge cleaning tool, in which a large number of water sprinkling holes 10 are arranged on the surface of the hollow pipe 9 for supplying cleaning water to the backing roll surface and the tip of the brush. Brush hairs 11 are planted on the other surfaces. The hollow pipe 9 is rotatably connected to the wash water pipe 14 by a rotor seal 15.

In addition, the intervals for installing the brushes on the backing roll 1 may be fixed at intervals that allow the brushes to contact and rotate.
Preferably, they are installed using a jig that can adjust the spacing.

Since the brush is in contact with the backing roll, it rotates with the rotation of the backing roll, so no special driving device is required. However, depending on the speed and cleaning hole, water may be scattered, so it is recommended to install a driving device to control the rotation. desirable. Furthermore, it is generally preferable to be able to rotate in the forward and reverse directions.

The amount of washing water, the temperature of the washing water, the direction of rotation, and the number of rotations are arbitrarily selected depending on the coating liquid used, and are not particularly limited. The material of the bristles of the brush is preferably one that does not damage the backing roll and does not allow the coating liquid to easily adhere or accumulate thereon, but any material that can withstand use is preferable.

The brush portion is preferably replaceable, and in this example is jointed at a joint 12. Further, a plate 13 is provided to prevent water from flowing from the cleaning device to the side surface of the packing roll 1. The edge cleaning tool is not limited to this, and as another example, instead of using a perforated hollow pipe as the cleaning water supply means, a supply nozzle is separately provided and the cleaning water is supplied to the contact surface between the backing roll 1 and the brush 8. Cleaning water may be supplied, or another example may be a combination of a doctor and a cleaning shower.

Next, to explain the cleaning method of the backing roll cleaning device of the present invention, the web 5 before coating is removed from the applicator roll 2.
It enters the coating device from the rear in contact with the backing roll 1. Application liquid is applicator roll 2 from color pan 3
The coating is transferred to the web 5 by the nip between the applicator roll 2 and the backing roll 1, and scraped off by the blade 4 to the required coating amount. Most of the coating liquid transferred to the coating liquid transfer portion a of the backing roll outside the width of the web 5 is scraped off by the blade 4, but the backing roll 1
The coating liquid left on the top is diluted with cleaning water from a brush (edge cleaning tool) 8 and peeled off from the surface of the backing roll 1 by rotation of the brush, and then the entire width of the backing roll is further diluted with cleaning shower water 7. The diluted coating fluid and other dirt are scraped off by the cleaning doctor 6,
At the nip between the cleaning doctor 6 and the backing roll 1, the cleaning water is washed away by a shower 7 and discharged to both sides of the cleaning doctor 6. Here, the width of the cleaning doctor 6 is slightly larger than the width of the backing roll 1, and the cleaning water is discharged from the lateral end of the doctor through a cleaning water discharge gutter provided therein.

The pressure of the cleaning doctor 6 against the backing roll 1 is controlled by a pressure cylinder.

Example 2 Using the backing roll cleaning device of Example 1, 52 Q
A coating liquid of the following composition was applied to one side of a web of /rd for 4 hours at a coating amount of 12q/Td at a speed of 900 m/ll1 inch, but no stains were generated on the cleaned doctor edge.

Coating liquid> 50 parts by weight of kaolin clay, 50 parts by weight of heavy charcoal, and 0.5 parts by weight of polyacrylic acid were dispersed and diffused in water to adjust the solid content concentration to 72% by weight, and 10 parts by weight of methiolene-butadiene latex was added to the slurry. parts, 5 parts by weight of phosphoric acid ester starch was added, and the solid content concentration was 6 parts.
It was set to 4% by weight.

Comparative Example 1 Coating was performed under the same conditions as in Example 2 except that a conventional cleaning device was used, except that the edge cleaning tool was removed. As a result, stains appeared on the cleaning doctor edge after about 1 hour. I started doing it.

[G] Effects of the invention As is clear from the examples, by selectively providing the backing roll edge section before the conventional cleaning doctor edge, stains generated on the conventional cleaning doctor edge are significantly reduced. It became possible.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a backing roll cleaning device showing one embodiment of the present invention. FIG. 2 is a schematic front view of FIG. 1. Third
The figure is a schematic diagram of the edge cleaning tool. 1...Backing roll 2...Applicator roll 3...Color pan 4...Doctor 5...
Web - 5'...Web end 6...Cleaning doctor 7...Cleaning shower 8...Edge cleaning tool (brush)

Claims (3)

[Claims] (1) A backing roll cleaning device equipped with a cleaning shower and a cleaning doctor over the entire surface width of a backing roll having a metering mechanism, characterized in that edge cleaning tools are provided on both sides of the backing roll above the shower. backing roll cleaning equipment. (2) The backing roll cleaning device according to claim 1, wherein the edge cleaning tool is a brush capable of supplying cleaning water. (3) In a coating device consisting of a metering section, an applicator section, and a backing roll, a cleaning shower is set above the cleaning doctor provided over the entire width of the backing roll surface on the opposite side of the metering section and applicator section. A backing roll cleaning method, comprising cleaning the coating liquid transferred to the backing roll using a backing roll cleaning device each equipped with an edge cleaning tool on both sides of the backing roll above the cleaning shower.