JP2002263555A - Apparatus for preventing stain of coating liquid spraying head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deposition of stains in the surrounding of a head including the tip part of a lip independently of the ambient conditions. SOLUTION: In a coating liquid spraying head 3 comprising a pair of lips 9 are installed upward in an upper part of a head casing 6 in a manner that their tip ends are projected out of the head casing 6, a water channel 13 is installed in the tip end parts of the lips 9 covering the entire length in the longitudinal direction and a large number of water current outlets 14 communicated with the water channel 13 are formed outside in the vicinity of the most tip end parts at prescribed pitches in the longitudinal direction. A water recovery gutter 15 is formed in the lower end part of the head casing 6 positioned at a lower side than the tip end parts of the lips 9. Stains are washed out with water W flowing out of the water current outlets 14 to avoid stain deposition and recovered in the water recovery gutter 15 to prevent the stains from contaminating in a coating liquid circulation system.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing a coating liquid jet head used in a blade coater or a rod coater from being used as a coating device for applying a coating liquid to the surface of paper produced in a paper mill as base paper. It is about.

[0002]

2. Description of the Related Art Paper produced in a paper mill is not immediately used as it is, but may be used as a base paper for further processing to obtain a processed paper as a product suitable for a desired purpose. Many. There are various types of processed paper, one of which is coated paper. The coated paper is manufactured by applying a coating liquid (color for coating) to the surface of the paper, and a coating apparatus is used as an apparatus therefor.

As one of such coating apparatuses, there is a blade coater whose outline is shown in FIG. The blade coater includes a coating liquid jet head 3 called a fountain that extends parallel to the longitudinal direction of the backing roll 2 at a position near the lower side of the backing roll 2 on which the base paper 1 is wound and run. The excess amount of the coating liquid 4 applied to the surface of the base paper 1 from the coating liquid jet head 3 is provided at a position downstream of the position of the coating liquid jet head 3 in the rotation direction of the backing roll 2. A blade 5 for scraping is disposed so as to be in contact with the surface of the base paper 1, and first, the coating liquid 4 is jetted and supplied from the coating liquid jet head 3 toward the surface of the base paper 1, and the width of the coating liquid is applied to the surface of the base paper 1. The coating liquid 4 is uniformly applied to the base paper 1 in a predetermined direction, and then a surplus portion of the coating liquid 4 applied to the surface of the base paper 1 is scraped off with a blade 5 so that the surface of the base paper 1 has a required thickness. Make sure to form a uniform coating liquid film That.

[0004] The coating liquid jetting head 3 used in the blade coater is fed by a pump into a head casing 6 having a front end formed in a joint shape, as shown in an enlarged view in FIG. And a liquid reservoir 7 for uniformly distributing the applied coating liquid 4 in the width direction.
A pair of lips 9 are attached to the coating liquid outflow passage 8 formed so as to extend from the top to the tip side (upward) of the coating liquid so as to protrude above the head casing 6 in parallel at a required interval and upward. A slit 10 continuous with the outflow channel 8 is formed so that the coating liquid 4 can be injected and supplied from the liquid reservoir 7 through the slit 10 between the coating liquid outflow channel 8 and the lip 9.

In the coating liquid jet head 3, if the coating liquid 4 scattered at the time of injection supply or the coating liquid 4 scraped off by the blade 5 adheres as dirt around the head, it must be cleaned. The cleaning operation is difficult, and in particular, when the coating liquid 4 adheres and accumulates as dirt on the tip (upper end) of the lip 9, the flow of the coating liquid 4 is obstructed, and the uniform jet supply is hindered. Conventionally, a water cooling jacket 11 is provided inside the tip of the lip 9 and a water cooling jacket 12 is also provided on the outer surface of the head casing 6.
A countermeasure is taken to prevent the accumulation of dirt by allowing the cold water cooled by the refrigerator to flow in the insides of the jackets 1 and 12 to cause condensation on the jacket surface. Further, when the effect is not enough just by passing water through the water cooling jackets 11 and 12, steam may be blown to the jacket surface.

[0006]

However, in the case of the dirt prevention measures by the water cooling jackets 11, 12, the degree of dew condensation is affected by the humidity and temperature of the atmosphere.
In some cases, the accumulation of dirt cannot be prevented, and there is also a problem that a refrigerator for producing cold water is expensive, so that equipment costs are increased. In addition, when steam is used in combination, dew condensation easily occurs, but a problem occurs in that a part of the steam hits the paper unevenly.

Accordingly, the present invention is intended to prevent the accumulation of dirt around the head including the tip of the lip without being influenced by the surrounding atmosphere and without using an expensive refrigerator or steam. Is what you do.

[0008]

According to the present invention, in order to solve the above-mentioned problems, a coating liquid supplied through a slit between a pair of lips provided at a tip portion of a head casing is wound around a roll. Water passages are provided along the entire length inside the tip portions of the pair of lips of the coating liquid ejecting head, which are adapted to be sprayed and applied to the surface of the running base paper, and are provided outside the vicinity of the tip of the lip. In addition, a large number of water outlets for allowing water in the water passage to flow out are formed at required pitch intervals.

If a small amount of water is discharged from the water outlet to uniformly wet the outer surface of the lip tip to the outer surface of the head casing, the dirt flows down with the water, so that dirt is deposited around the head. Disappears.

Also, by providing a water collecting gutter at the lower end of the head casing, dirt-adhered water can be collected by the water collecting gutter, thereby preventing the water from entering the color pan. Diluting the coating liquid in the pan is prevented.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. As shown in FIG. 4, an upper part of a head casing 6 communicates with an internal liquid reservoir 7 through a coating liquid outflow passage 8. In the coating liquid ejecting head 3 in which a slit 10 is formed and a pair of lips 9 are attached so that the tip protrudes above the head casing 6, the base paper 1 (FIG. 3) is provided inside the tip of the lip 9. A water passage 13 is provided over the entire length in the longitudinal direction along the width direction, and the water passage 13 is provided outside the vicinity of the tip of the lip 9 (for example, about 5 mm from the tip of the lip 9).
mm), a small-diameter (for example, having a diameter of 1 to 3 mm) circular water outlet 1 communicating with the water passage 13.
4 are drilled at a required pitch interval so that the waters flowing out of the adjacent water outlets 14 merge with each other.
3, the water W is oozed out through the respective water outlets 14, and the outer surface of the head casing 6 located below the tip of the lip 9 (on the downstream side in the rotation direction of the backing roll 2 shown in FIG. 3). A water collecting gutter 15 is provided at the lower end, and water W flowing down from the outside of the tip of the lip 9 can be collected by the water collecting gutter 15 along the outer surface of the head casing 6.

During operation, the coating liquid jet head 3 configured as described above supplies the water W to the water passage 13 in the tip of the lip 9 and supplies a small amount of water through the water outlet 14 near the tip of the lip. W is allowed to flow directly so as to ooze continuously or intermittently. As a result, the outer surface of the head casing 6 from the outer surface of the tip of the lip 9 to the outer surface is always uniformly wet with the water W. Ready, lip 9
Even if a part of the coating liquid ejected from the tip of the lip 9 adheres to the outside of the tip of the lip 9, it can flow together with the water W, and the accumulation of dirt can be prevented. Therefore, the cleaning cycle around the head can be lengthened, and the stop time of the machine for cleaning can be reduced. In addition, water W
Can be recovered by the water recovery gutter 15 at the lower end of the head casing 6 and cannot be received by the color pan disposed below. There is no such thing as diluting.

In the present invention, since the water outlet 14 is provided outside the vicinity of the tip of the lip 9 as described above, the coating liquid 4 adheres to the tip of the lip 9 and accumulates. Can be reliably prevented from occurring.
Therefore, the flow of the coating liquid 4 jetted and supplied from the slits 10 between the lips 9 is not obstructed, and the occurrence of uneven coating can be prevented.
Further, since the water W flowing out from the water outlet 14 does not need to be cold water, the conventional refrigerator is unnecessary and the cost is advantageous. Further, since it is not necessary to use steam together, the steam is not used. Does not cause a problem of inconvenience.

Next, FIG. 2 shows another embodiment of the present invention. In the same configuration as shown in FIG. 1, the hole shape of the water outlet 14 provided outside the vicinity of the tip of the lip 9 is changed. It shows an example in the case of another shape, as an example,
The water outlet 16 has a long hole shape.

In the case shown in FIG. 2, the water W can be made to flow more uniformly in the width direction, so that the effect of preventing the accumulation of dirt can be further improved.

In the above embodiment, an example of application to the coating liquid ejecting head 3 used in the blade coater has been described. However, the same can be applied to the coating liquid ejecting head used in the rod coater. The water outlets provided in the portion may be arranged in a staggered manner in the width direction, may have any shape other than that shown and described, and may be variously modified without departing from the gist of the present invention. Of course.

[0018]

As described above, according to the apparatus for preventing contamination of the coating liquid jet head of the present invention, the coating liquid supplied through the slit between the pair of lips provided at the tip of the head casing is rolled. Water passages are respectively provided over the entire lengths inside the tip portions of the pair of lips of the coating liquid ejecting head which is adapted to eject and apply to the surface of the stencil which is wound around and travels over the entire length thereof. On the outside near the tip,
Since a large number of water outlets for draining the water in the water passages are formed at a required pitch interval, a small amount of water is continuously or intermittently discharged from the water outlet, so that the outside of the lip is provided. It can be uniformly wet from the surface to the surface of the head casing, so that dirt can flow with water, without being affected by atmospheric conditions.
Moreover, it is possible to prevent the accumulation of dirt around the head without using a refrigerator or steam, and in particular, it is possible to reliably prevent the accumulation of dirt at the tip of the lip, thereby preventing the occurrence of uneven coating. In addition, since the water collecting gutter is provided at the lower end of the head casing, the water with dirt can be collected by the water collecting gutter, so that the water is mixed into the coating liquid circulation system. It has an excellent effect that the coating solution is not diluted and the coating solution is not diluted.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an embodiment of a stain prevention device for a coating liquid ejection head according to the present invention.

FIG. 2 is a schematic diagram showing another embodiment of the present invention.

FIG. 3 is a schematic view showing an example of a blade coater.

FIG. 4 is a schematic view showing an example of a conventional coating liquid ejection head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Base paper 2 Backing roll (roll) 3 Coating liquid jet head 4 Coating liquid 6 Head casing 9 Lip 10 Slit 13 Water passage 14 Water outlet 15 Water recovery gutter 16 Water outlet W Water

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D073 AA01 BB03 CC03 4F041 AA12 AB01 BA07 BA12 BA53 BA59 BA60 CA04 CA23 CA28 4F042 AA22 BA08 CC04 CC08 4L055 BE08 CH12 CH14 FA22 GA19

Claims (2)

[Claims] A coating liquid supplied through a slit between a pair of lips provided at a tip portion of a head casing is applied by spraying onto a surface of a base paper running around a roll. Inside the tip portions of the pair of lips of the working liquid jet head, water passages are respectively provided over the entire length, and a number of water outlets for discharging water in the water passages are provided outside the vicinity of the tip of the lip. A coating liquid jet head having a configuration in which the coating liquid jetting head is formed at a required pitch interval. 2. The apparatus according to claim 1, wherein a water collecting gutter is provided at a lower end of the head casing.