JP2002285497A - Method and device for promoting aqueous solution permeability of back coater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for promoting the aqueous solution permeability of a back coater, by which the permeability of an aqueous solution into coated paper can be promoted, even when the coated paper transported to the back coater is excessively dried. SOLUTION: Nozzles 10 for uniformly blowing out steam on the back side of coated paper 9 in the width direction of the paper are disposed on the upstream side of the back coater 1 for coating an aqueous solution on the back side of the coated paper 9 whose front side is coated. The nozzles 10 are disposed at positions apart from an aqueous solution-coating position only at distances enabling the impregnation of the water into the steam-blown coated paper 9 so that the water content of the coated paper 9 increases in an amount of about 0.2 to 3%. Since the coated paper 9 is already humidified before the coating of the aqueous solution, the permeability of the aqueous solution in the process for coating the aqueous solution can be promoted.

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 enhancing the permeability of an aqueous solution of a back coater for applying an aqueous solution to paper in a coated paper manufacturing facility.

[0002]

2. Description of the Related Art Paper manufactured in a paper mill is rarely used immediately as it is, and it is sometimes 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, and one of them is a coated paper (coated paper). The coated paper is manufactured by applying a coating solution by applying a coating liquid to the surface of the base paper using a coating machine such as a blade coater or a curtain coater.

[0003] In the equipment for producing the coated paper, for the purpose of adjusting the water retention of the paper in consideration of the ink absorbency at the time of printing, or correcting the warpage of the paper,
The coated paper after the coating liquid is applied to one side (front side) and dried is led to a back coater as an aqueous solution coating apparatus, and the back coater is used to apply an aqueous solution (coating the aqueous solution) on the back side of the coated paper. (Including a thin coating liquid in which the liquid is dissolved).

FIG. 2 shows an example of a back coater 1 used in a coated paper manufacturing facility. An aqueous solution tank 3 formed longer than the paper width on a support 2 elongated in the paper width direction.
Is placed, and a dip roll 5 is arranged so that a lower portion thereof is immersed in the aqueous solution 4 in the aqueous solution tank 3 so that both shaft ends are rotatably supported by the frame 2 a on the support base 2. The coater rolls 6 are arranged in parallel so as to overlap each other. Similarly, both ends are rotatably supported by the frame 2a, and the rolls 7 and 8 are arranged in parallel above the coater roll 6. The two shaft ends are rotatably supported on the upper end of the frame 2a, and the coated paper 9 which has been coated and run on one side (surface) is wound on the roll 8 and then wound on the upper surface of the coater roll 6. After that,
At this time, the aqueous solution 4 transferred from the dip roll 5 to the coater roll 6 is applied from the coater roll 6 to the back surface of the coated paper 9 so as to be sent to the downstream side through the space between the coater roll 6 and the roll 7. Coating is performed. Note that the coated paper 9 after the aqueous solution coating is dried by a downstream dryer.

[0005]

However, in the case of the aqueous solution coating operation using the back coater 1, since the back surface of the coated paper 9 is dry, the aqueous solution 4 hardly adheres,
There is a problem that the permeability of the aqueous solution 4 is poor even if a large amount of the aqueous solution 4 is applied.
There is a problem that the permeability of the aqueous solution 4 is poor, but until now, even if the coated paper 9 is over-dried, it is not possible to take some measure before the application of the aqueous solution to promote the permeability of the aqueous solution 4. Therefore, the coated paper after being dried by the downstream dryer may not have the desired water retention amount and properties.

[0006] Therefore, the present invention promotes the penetration of the aqueous solution into the coated paper to obtain the desired amount of water retention and properties even when the coated paper to be coated with the aqueous solution by the back coater is excessively dried. To be able to

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method for applying an aqueous solution to the back side of a coated paper having a coated surface by using a back coater. A method of promoting the permeability of an aqueous solution of a back coater so as to humidify by spraying steam or humidified air on the back of the paper,
Also, steam or humidified air is sprayed on the back side of the coated paper at the upstream position of the back coater for performing the coating for applying the aqueous solution to the back side of the coated paper after the surface is coated. The back coater has a structure in which a nozzle is installed for humidifying the aqueous solution.

When the coated paper having the coated surface is sent to the back coater, steam or humidified air is already blown on the back surface of the coated paper to humidify the back surface of the coated paper. By performing the aqueous solution coating on the back surface of the coated paper, the permeability of the aqueous solution is promoted.

[0009]

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. 2, the lower portion is immersed in an aqueous solution 4 in an aqueous solution tank 3 placed on a support 2. Then, a coater roll 6 is disposed so as to overlap the dip roll 5 whose both shaft ends are rotatably supported by the frame 2 a on the support base 2, and the roll 7 is disposed above the coater roll 6. 8 are arranged in parallel, and the coated paper 9 traveling from the upstream
After being wound along the upper surface of the roll, it is passed between the coater roll 6 and the roll 7 so that the deep roll 5
The aqueous solution 4 transferred to the coater roll 6 from above is applied to the back surface of the coated paper 9 and a plurality of guide rolls 11a,
11b and 11c are arranged at a required interval, and paper 9 coated with a coating liquid on one side (front surface) is guided by guide rolls 11a and 11c.
In a configuration in which the paper is guided to the roll 8 along the rolls 11b and 11c, a position between the guide rolls 11a and 11b and between the guide rolls 11b and 11c is directed toward the back surface of the coated paper 9 whose surface is coated. Nozzles 10 for spraying steam uniformly in the width direction of the paper to humidify them are installed in a plurality of stages at predetermined intervals in the running direction of the coated paper.
Each nozzle 10 is provided on the back surface of the coated paper 9 to be coated with the aqueous solution with
After applying steam, the back surface of the coated paper 9 is humidified, and then the aqueous coating is performed by the back coater 1.

The nozzle 10 at each stage for spraying steam on the back surface of the coated paper 9 to humidify the water is applied to the coated paper 9 before the aqueous solution 4 is applied by the back coater 1.
The back coater 1 is disposed so as to be increased by about a distance such that moisture can permeate the coated paper 9 onto which the steam has been blown.

When the aqueous solution is applied to the back surface of the coated paper 9 by the back coater 1, each nozzle 10 is attached to the back surface of the coated paper 9 at a position upstream of the roll 8 of the back coater 1 at a required distance. To evenly spray steam in the paper width direction,
When the water content of the coated paper 9 when the aqueous solution 4 is applied is 0.2 to 0.2
The coated paper 9 is humidified so as to increase by about 3%. In this case, there is an advantage that the vapor particles are very fine and easily penetrate even with dry paper as compared with mere water. Therefore, when the aqueous solution 4 is applied from the coater roll 6 to the back surface of the coated paper 9 humidified by the spray of steam, the aqueous solution 4 easily penetrates, and even if the coated paper 9 is excessively dried, The permeability of the aqueous solution 4 can be easily promoted, and the coated paper after drying can have the desired water retention and properties.

In the above, the aqueous solution 4
When a thin coating liquid in which the coating liquid is dissolved in the aqueous solution is applied to the back surface of the coated paper 9 when is applied, the permeability of the thin coating liquid is improved by being humidified in advance. be able to. In the above, when the aqueous solution 4 is applied by the back coater 1, steam is sprayed from the nozzle 10 to the back surface of the coated paper 9 so that the moisture of the coated paper 9 increases by about 0.2 to 3%. The reason is that the permeability of the aqueous solution 4 into the coated paper 9 and the drying property in the downstream are taken into consideration. That is, generally, paper having a higher water retention has better water permeability. For example, when the paper has a water content of about 2 to 7%, the water permeability is sufficiently exhibited. Since the applied coated paper 9 has a drying step later, considering the permeability and drying property of the aqueous solution 4,
It is optimal to increase the water content by about 0.2 to 3% before applying the aqueous solution.

In the above-described embodiment, a case has been described in which steam is blown from the nozzle 10 in order to humidify the back surface of the coated paper 9, but humidified air may be blown. It goes without saying that various changes can be made without departing from the spirit of the present invention.

[0015]

As described above, according to the method and apparatus for promoting the aqueous solution permeation of the back coater of the present invention, before the application of the aqueous solution by the back coater to the back surface of the coated paper whose surface has been processed. Since there is a method and apparatus for enhancing the permeability of an aqueous solution of a back coater in which steam or humidified air is blown onto the back surface of the coated paper in advance to humidify the coated paper, The back side of the paper can be humidified, and the aqueous solution can be applied to the back side of the coated paper by applying the aqueous solution to the back side of the humidified coated paper. Even if the paper is over-dried, the permeability of the aqueous solution to the back of the coated paper can be promoted by simple means, so that the coated paper after drying can have the desired water retention and properties. Excellent effect Exhibit.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one embodiment of an apparatus for promoting aqueous solution permeability of a back coater according to the present invention.

FIG. 2 is a schematic diagram illustrating an example of a back coater.

[Explanation of symbols]

 1 back coater 4 aqueous solution 9 coated paper 10 nozzle

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasushi Tachikawa 1st Shin-Nakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Ishikawajima-Harima Heavy Industries, Ltd. Yokohama Engineering Center F term (reference) 4D075 AC23 AC54 BB57X CA35 CA40 DA04 DB18 DC50 EA60 4F042 AA22 BA08 CB05 ED05 4L055 BE01 CH30 FA30 GA19

Claims (2)

[Claims] 1. Before applying an aqueous solution to a back surface of a coated paper having a coated surface by a back coater, steam or humidified air is sprayed on the back surface of the coated paper to humidify in advance. A method for promoting the permeability of an aqueous solution of a back coater. 2. Steam or humidified air is blown to the back surface of the coated paper at a position upstream of a back coater for performing coating for applying an aqueous solution to the back surface of the coated paper after the surface is coated. An aqueous solution permeation promoting device for a back coater, having a configuration in which a nozzle for humidifying coated paper is installed.