JP4556714B2 - Lead-in paper roll of coating equipment - Google Patents

Description

  The present invention relates to a lead-in paper roll for introducing a web into a coating portion of a coating apparatus in a coating apparatus installed in a paper machine or the like.

In a paper machine for producing paper, a wet paper web is formed in a wire part, dehydrated in a press part, and further dried in a dryer part to produce paper.
Usually, a dryer part is divided into a pre-dryer part and an after-dryer part, and a coating device called a size press is arranged between these dryer parts, and this coating device gives water resistance to the paper surface. Therefore, chemicals such as sizing solution that prevents ink bleeding are applied.
Since this coating device was installed for the purpose of applying sizing liquid for a long time, the name “size press” has been used. However, not only the sizing liquid but also the surface strength and smoothness of paper are improved. It is used to apply chemicals for various purposes such as improving rigidity and dyeing. In addition, a color (paint) for coated paper, which was conventionally applied by a separate coating machine (coater), can be applied and used as an undercoat for coated paper, or for the production of fine coated paper. Is also used.

  As a type of such a coating apparatus, a pound type size press and a transfer type size press are known. The pound type size press forms a liquid pool (pound) of the coating liquid at the nip portion of two rolls, and the web passes through the nip portion (coating portion) having the pound to thereby apply the coating liquid. Is a form to be applied.

  As the transfer type size press, there are a gate roll type and a blade type such as a shim sizer. The gate roll type is usually referred to as a gate roll coater, and as shown in FIG. 1, the gate roll type is composed of a total of six rolls on which the front and back surfaces of the web are coated using three rolls. That is, it consists of a pair of applicator rolls that are in direct contact with the web, a central metering roll installed for each applicator roll, and an outer fountain roll, and the coating supplied between the fountain roll and the metering roll A liquid is transcribe | transferred to each applicator roll, and a coating liquid is apply | coated to the front and back of a web, when a web passes between these applicator rolls (coating part). The blade type is a type in which a coating liquid is supplied to an applicator roll that is in contact with the web, and the coating liquid is scraped off by the blade to adjust the coating amount. A rod type using a rod instead of a blade is also known.

  In order to supply paper at an appropriate angle to the coating unit of these coating apparatuses, a paper roll called a lead-in roll is usually installed immediately before the coating unit. In addition, a paper roll called a lead-out roll and an expander roll for preventing wrinkles are installed immediately after the coating section in order to discharge the web from the coating section at an appropriate angle and supply it to the after dryer. There is a case.

In such a coating apparatus, since the web is not dried until it leaves the coating apparatus and enters the after-dryer, there is a problem that the lead-out roll and the expander roll are contaminated by the adhesion of the coating liquid. there were.
As a method for solving such a problem of coating stain, in Patent Document 1, when a coated paper is produced by applying a paint to a coated base paper made by a paper machine by a coater, the coating process and drying are performed. During the process, in the paper roll that is in direct contact with the coating surface of the coated paper that has been coated with paint, the surface of the roll from the inside of the paper end passage surface of at least the minimum paper width that is applied by the coater A paper roll for a coater is disclosed in which a central portion is coated with chrome plating and the other portions are coated with ceramic or cermet.

  Patent Document 2 discloses that in a gate roll coater, the surface of one gate roll is coated with ceramics having excellent durability, corrosion resistance, wettability, and friction coefficient.

Japanese Patent Laid-Open No. 08-098773 Japanese Patent Laid-Open No. 08-169063

As described above, in rolls that are in direct contact with the coating liquid during coating and rolls that are in direct contact with the coated web before drying, troubles due to contamination of the roll with the coating liquid are regarded as a problem. Measures have been taken.
However, as a result of intensive studies on the causes of paper breakage and paper quality defects in the paper machine, the present inventors are not limited to these rolls as the cause of trouble in coating, and lead-in paper rolls before coating are also included. Focusing on the cause of trouble, the present invention has been completed.
That is, due to high speed of the paper machine, etc., the coating liquid mists and scatters due to high speed rotation of the roll to which the coating liquid is applied, and the lump that adheres to the surface of the lead-in roll and solidifies is peeled off. If it falls on the running web or enters the circulation line of the coating liquid, a lump of the coating liquid is applied to the web, causing paper breakage or causing quality problems due to paper defects. I understood that it was the cause. Therefore, in order to further improve the coating trouble, it is necessary to take measures not only for the adhesion prevention to the roll surface after coating but also for the lead-in paper roll before coating. is there.

  The present invention has been made in view of such a conventional situation. In a coating apparatus such as a paper machine, the coating is applied to the surface of a lead-in paper roll before coating as well as a roll after coating or after coating. The purpose is to prevent problems caused by liquid adhesion.

In order to achieve the above object, the first invention of the present application is a lead-in paper roll that is introduced into a coating unit of a coating apparatus that applies a coating solution to paper and is positioned at the top of the coating apparatus. Te, wherein the Rutotomoni comprising a flow passage through the roll body inside the cooling fluid, the wall surface of the roll body is coated with a thermally sprayed ceramic coating.
Here, as the cooling fluid, a fluid capable of cooling the inside of the roll body and generating condensed water on the roll surface, for example, cooling water can be employed.

  In the second invention of the present application, the peripheral wall of the roll body has an inner / outer double wall structure, the flow path is formed between the inner / outer double walls, and the roll passes through a cooling fluid supply path formed inside the roll shaft. The cooling fluid supplied to the central part of the main body is discharged to the outside of the roll main body via the flow path between the double walls.

  The third invention of the present application is characterized in that the cooling fluid is cooling water.

The fourth invention of the present application is characterized in that the coating apparatus is installed between dryer parts of a paper machine.
Here, “between the dryer parts” means between the dryer parts arranged in the front and rear, such as a pre-dryer part and an after-dryer part.
Also, the coating apparatus in this case is usually called a size press.

The fifth invention of the present application is characterized in that the coating device is a gate roll coater.

  As described above, the lead-in paper roll according to the present invention generates condensed water on the surface of the roll body by cooling the inside of the roll body with a cooling fluid, and the coating liquid splashes on the surface of the roll body by the condensed water. Can be prevented from adhering and solidifying, and contamination can be prevented. Therefore, a lump such as coating liquid that adheres to the surface of the lead-in paper roll peels off and prevents troubles such as coating defects and paper breakage caused by dropping on the running web or coating device. can do. In addition, in order to prevent these troubles, it is necessary to stop the operation of the paper machine, the coating machine, etc. and periodically clean the lead-in paper roll. The number of times can be greatly reduced. Therefore, many effects can be expected, such as contributing to efficiency and cost reduction of the papermaking process and the coating process.

  Further, according to the second invention, the roll body peripheral wall has an inner / outer double structure, a flow path is formed inside the roll surface, and a cooling fluid supplied to the roll center is cooled through the flow path. As a result, the speed of the cooling fluid can be increased, the thermal conductivity between the roll surface and the roll surface can be increased, and the amount of cooling fluid is more efficient than the flow of cooling water inside the roll. Is. As a result, the cooling efficiency is improved and the roll surface can be more reliably condensed.

  According to the third aspect of the invention, the roll body is cooled using cooling water such as industrial water or tap water that can be easily used as the cooling fluid, so that the roll surface can be condensed at low cost and with certainty.

Furthermore, according to the first invention, since the peripheral wall of the roll body is coated with ceramics, the surface is kept smooth due to wear resistance (hardness) and corrosion resistance which are the original properties of ceramics. Due to the water wettability of ceramics, the roll surface is easily wetted by condensed water. Accordingly, it is difficult for the coating liquid droplets or the like to adhere to the surface of the roll body, and it is difficult to get dirty.

According to the fourth invention, the paper machine generally has a higher operating speed than the off-line coating machine, and the coating liquid is likely to splash. Can be expected.

According to the fifth invention, the gate roll coater has as many as six rolls used for coating, and a lump of the coating liquid adhering to the lead-in roll falls and mixes into the coating liquid circulation line. Therefore, when the lead-in paper roll of the present invention is used for a gate roll coater, a great effect can be expected.

An example in which the lead-in paper roll according to the present invention is applied to a lead-in roll of a gate roll coater of a paper machine will be described below with reference to the drawings.
In the paper machine of this example, as shown in FIG. 1, a gate roll coater 3 is arranged as a size breath between a pre-dryer part 1 and an after-dryer part 2.

  The gate roll coater 3 includes a pair of applicator rolls 5a and 5b that are in direct contact with a web 4 and a central metering roll 6a and 6b installed for each applicator roll 5a and 5b, and an outer fountain. The coating liquid 8 composed of rolls 7a and 7b and supplied between the metering rolls 6a and 6b and the fountain rolls 7a and 7b is transferred to the applicator rolls 5a and 5b. The coating liquid is applied to the front and back of the web 4 by passing through the coating portion 9 between the talols 5a and 5b. In this example, in order to produce high-quality paper and fine coated paper, not only sizing liquid but also color (paint) is applied.

In order to supply the web 4 to the coating unit 9 at an appropriate angle, a lead-in paper roll 10 is installed immediately before the coating unit 9, and the web 4 is discharged from the coating unit 9 at an appropriate angle. A lead-out paper roll 11 is installed immediately after the coating unit 9 in order to supply the cylinder dryer 2 of the after dryer part. In addition, instead of the lead-out paper roll 11, an expander roll that can remove wrinkles of the web 4 may be installed, or both rolls may be installed.
Also, another paper roll 12 is installed between the cylinder dryer 1 of the pre-dryer part and the lead-in paper roll 10.

  3 and 4, the lead-in paper roll 10 fixes circular side plates 16 and 17 to inner end portions of left and right roll shafts 14 and 15 that are rotatably supported by a bearing 13. At the same time, the cylindrical outer peripheral wall 18 is fixed between the outer peripheral edges of the side plates 16 and 17, and the cylindrical inner peripheral wall 21 is fixed by the support members 19 and 20 fixed to the inner surfaces of the side plates 16 and 17. Then, a roll main body 10 ′ having an inner and outer double wall structure is configured, and a flow channel (flow path) 22 is formed between the outer peripheral wall 18 and the inner peripheral wall 21.

  A water supply pipe 24 passes through the axial center of one roll shaft 14 so as to be rotatable with respect to the roll. One end of the water supply pipe 24 communicates with a water supply port 25 for cooling water, while the other end is a roll shaft. 14 protrudes from the inner end, passes through the axis of the roll body 10 ′, and is inserted into the inner end of a through hole 26 provided in the axis portion of the other roll shaft 15. The outer end of the through hole 26 diverges radially inside the side plate 17 and communicates with the flowing water channel 22 between the outer peripheral wall 18 and the inner peripheral wall 21. Then, the cooling water supplied from the water supply port 25 flows into the water flow channel 22 via the water supply pipe 24 and the through hole 26 as the cooling fluid supply channel, and the other roll shaft 15 side in the water flow channel 22 To flow toward the one roll shaft 14 side.

  Further, a drainage channel 27 is formed outside the water supply pipe 24 in the axial center portion of one roll shaft 14. One end of the drainage channel 27 communicates with a drainage port 28 provided on the roll shaft 14, and the other end side is radially branched inside the side plate 16 to communicate with the flowing water channel 22. The cooling water that flows from the roll shaft 15 side toward the one roll shaft 14 side is discharged to the outside of the roll body 10 ′ via the drainage channel 27 and the drainage port 28.

  The cooling water is industrial water or tap water of about 15 to 35 ° C., and the cooling water flows in the flow channel 22 as described above to cool the inside of the outer peripheral wall 18. The surface temperature of the cylinder dryer of the dryer part is normally at a high temperature of about 100 ° C., and the peripheral wall surface of the roll body 10 ′, that is, the surface of the outer peripheral wall 18 is 70 ° C. due to contact with the web 4 that has passed through the dryer part. Due to the cooling action by the cooling water, dew condensation water is generated on the outer peripheral wall 18 surface, and the dew condensation water causes the coating liquid droplets and the like to adhere to the surface of the roll body 10 'and solidify. It can prevent and prevent dirt.

  The outer peripheral wall 18 of the roll main body 10 'is usually manufactured by a steel pipe or the like. In this example, the surface of the peripheral wall, that is, the surface of the outer peripheral wall 18, for example, surface roughness is used in order to prevent generation of rust, scratches, and wear. (Ra): A smooth surface coated with a ceramic sprayed coating 23 of about 1.0 to 1.8 μm is formed so that the coating liquid droplets do not easily adhere to the surface and are not easily contaminated. Further, ceramic spraying can use a technique conventionally used for spraying rolls, and the thickness of the ceramic spray coating 23 can be set to, for example, about 200 to 600 μm. Moreover, the hardness of the ceramic sprayed coating 23 can be set to Hv700-1000, for example.

Although the doctor is not attached to the lead-in paper roll 10 of this example, you may install a doctor and the example which installed the doctor 30 is shown in FIG. 2 (reference example) . The doctor 30 includes a blade 31 for scraping off dirt and the like adhering to the surface of the roll body 10 ′, and a receiving tray 32 for receiving the scraped dirt, and the blade 31 is a resin blade. The wear of the ceramic film 23 on the roll surface can be prevented and the roll surface can be kept smooth.

  The gate roll coater 3 employing the lead-in paper roll 10 having the above-described configuration is free from troubles such as coating defects and paper breaks caused by a lump of coating liquid falling on a running web or coating device. Can be prevented. Further, in the paper machine of the example of FIG. 1 in which the gate roll coater 3 is installed, the regular cleaning work of the lead-in paper roll can be reduced to once a month when the conventional product is required about three times a month. did it.

In addition, although detailed description and illustration are abbreviate | omitted, it is good to provide the means to provide the liquid for wear and damage prevention to the contact part of the braid | blade 31 shown in the example of FIG. 2, and a roll surface. The liquid application means can use the dew condensation water described above, but can be configured to spray liquid such as mist water on the contact surface between the roll surface (surface of the outer peripheral wall 18) and the blade 31.
Although shower water can be applied to the roll surface or the lower part of the roll can be applied to the water, it is not preferable that the amount of water is too large to go around the roll surface.
In addition, it is not an essential requirement to apply a liquid when using the doctor 30, and an operation without applying a liquid is also possible with emphasis on prevention of water circulation.

  Also, the lead-out roll 11 and the paper roll 12 described above are coated with a ceramic sprayed coating on the peripheral wall surface of the roll body as in the lead-in paper roll 10, and a cooling water circulation path is provided in the roll body. Therefore, it is effective to form the coating liquid so as to prevent adhesion and contamination of the coating liquid. Furthermore, it is also effective to install a doctor 30 having a resin blade 31 and a liquid application means to a contact portion with the blade 31 for these rolls.

  As mentioned above, although the example of embodiment of this invention was demonstrated based on drawing, the structure and use of the lead-in paper roll which concern on this invention are not limited to the thing of the example of illustration, In the category of the technical idea of each claim statement It goes without saying that various modifications are possible.

  The configuration of the lead-in paper roll according to the present invention is useful for preventing the surface of the roll from being soiled, and has been used for a lead-out paper roll and other paper rolls of a coating machine that has conventionally taken measures against contamination of the coating liquid. A similar configuration can be applied. In addition, it goes without saying that the lead-in paper roll according to the present invention can be applied not only to a paper machine but also to an offline coater (coating machine) as long as it is a coating apparatus.

The simplified side view which shows the gate roll coater which concerns on an example of embodiment of the lead-in paper roll of this invention. The simplified side view which shows the gate roll coater which concerns on the reference example of embodiment of the lead-in paper roll of this invention. The expansion longitudinal front view of the lead-in roll in FIG. 1 or FIG. Sectional drawing which follows the (X)-(X) line | wire of FIG.

Explanation of symbols

1: Pre-dryer part cylinder dryer 2: After-dryer part cylinder dryer 3: Gate roll coater
4: Web
8: Coating liquid 9: Coating section 10: Lead-in paper roll 10 ': Roll body 18: Outer wall 21: Inner wall 22: Flow channel (flow channel)
23: Ceramic spray coating 24: Water supply pipe (cooling fluid supply path)
30: Doctor 31: Blade

Claims (5)

A web is introduced into a coating portion of a coating apparatus that applies a coating liquid to the web, and is a lead-in paper roll positioned at the top of the coating apparatus , and has a flow path for passing a cooling fluid through the inside of the roll body. comprising Rutotomoni, lead-in paper roll peripheral wall surface of the roll body, characterized in that it is coated with a ceramic thermal sprayed coating.   The peripheral wall of the roll body has an inner / outer double wall structure, the flow path is formed between the inner and outer double walls, and is supplied to the center of the roll body through a cooling fluid supply path formed inside the roll shaft. The lead-in paper roll according to claim 1, wherein the cooling fluid is discharged to the outside of the roll body through a flow path between the double walls.   The lead-in paper roll according to claim 1 or 2, wherein the cooling fluid is cooling water. The lead-in paper roll according to any one of claims 1 to 3 , wherein the coating device is installed between dryer parts of a paper machine. The lead-in paper roll according to claim 4, wherein the coating device is a gate roll coater.

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