JP2010150707A - Method for making paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for making paper which does not impair the quality of its own, and also prevents the cracks of its soft roll without substantially modifying conventional production apparatus. <P>SOLUTION: The method for making paper includes conducting a surface treatment of paper made by a papermaking machine, using a calender, wherein a soft calender is installed on-line with the papermaking machine, and the width of paper to be fed to the soft calender is made wider than the effective surface length of the soft roll of the soft calender; preferably, the width is made wider by 5-30 mm on either side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to surface treatment of paper made by a paper machine using a soft calendar.

In general, paper is mixed with various types of pulp, such as mechanical pulp, chemical pulp, deinked pulp (DIP), etc., depending on the intended use. The resulting stock is made by a known paper machine.
After coating (or applying) coating chemicals (pigments, adhesives, etc.) as appropriate on the paper thus produced, surface treatment such as glazing is performed with a super calender or soft calender and the paper is wound up with a winder.

  Along with the trend toward higher quality in recent years, many papers are coated with paint chemicals on the surface and subjected to surface treatment such as glazing with a calendar. The conventional calendering process was mainly performed by supercalenders using low-temperature multistage rolls. However, since supercalenders use a large number of rolls, it is difficult to increase the speed. In recent years, the art is inferior in terms of durability, such as inferior durability, production efficiency is poor, it is not possible to cope with recent high-speed papermaking, and multiple supercalenders are required for one paper machine. For papers other than special uses such as paper and glassine paper, soft calendar processing that can be processed online with a paper machine tends to be employed.

This soft calender is composed of one or a plurality of sets of heating rolls and soft rolls, and the heating roll is a metal roll and heated to a high temperature of about 50 ° C. to 250 ° C. ing. The soft roll is provided with one or more layers of an elastic material such as hard rubber or plastic on a metal core.
The soft calender is composed of a pair of heating rolls and soft rolls or a pair of soft rolls. By passing the paper while applying pressure between the heating roll and the soft roll, smoothness, gloss, etc. The paper surface is modified.

However, in this soft calendar, paper passes between the heating roll and the soft roll that make a pair as described above. However, since the width of the paper to be passed is not always constant, there is paper between the heating roll and the soft roll. The part which does and the part which does not exist arise.
As a result, in the part where the paper exists between the heating roll and the soft roll, little heat is transferred from the heating roll to the soft roll due to the heat insulation effect of the paper, but in the part where the paper does not exist, the heating roll and the soft roll Will face each other directly, and the heat transferred from the heating roll to the soft roll will increase, and this part will be overheated. And this soft heating may generate | occur | produce a crack in a soft roll, especially its edge part.

The occurrence of this crack is already well known among those skilled in the art, and attempts have been made to cool it by blowing cold air over the overheated part, but the actual situation is that the cooling effect is not obtained with cold air. It is. For this reason, further solutions have already been proposed.
For example, according to Japanese Patent Laid-Open No. 7-11599 (Patent Document 1), there is a method of detecting a partial heat generation in the surface length direction of a soft roll, and spraying water on the heat generation portion to cool the heated portion. It is disclosed. Further, according to Japanese Patent Laid-Open No. 2000-73291 (Patent Document 2), a portion of the metal roll and / or elastic roll (heating roll and / or soft roll) where the paper is not in contact and both widthwise ends of the paper are The thing which sprayed the air-water mixing mist to the part to contact and cooled and prevented generation | occurrence | production of a crack is disclosed.
JP-A-7-11599 JP 2000-73291 A

In both of the above-described patent documents 1 and 2, water or air is sprayed on a portion of the heating roll and / or soft roll that is easily heated to cool it.
For this reason, if there is much spraying amount of water, it will humidify paper and will impair the quality of the paper as a product. Conversely, if the amount of water sprayed is small, a sufficient cooling effect cannot be obtained, and damage due to cracking or cracking of the intended soft roll cannot be prevented.
Also, in order to measure the surface temperature of the roll and to spray water or air, it is necessary to install a temperature measuring device or a water spraying device separately. A problem occurs.

The present invention provides a paper manufacturing method capable of preventing the occurrence of cracks in a soft roll without impairing the quality of the paper and without changing the conventional apparatus in terms of equipment. It is the purpose.

In the first aspect of the present invention, when manufacturing paper whose surface is processed with a calender, the width of the paper supplied to the soft calender is wider than the effective surface length of the soft roll of the soft calender. This is a method for producing paper.
In addition, the second invention of the present invention is characterized in that, in the first invention, the width of the paper supplied to the soft calender is 5 to 30 mm wider per side than the effective surface length of the soft roll of the soft calender. This is a paper manufacturing method.
Further, the third invention of the present invention is characterized in that, in the first and second inventions, after the surface treatment with the soft calender, the ears at both ends of the paper are cut with a slitter before being wound on the reel. This is a paper manufacturing method.
Furthermore, the fourth invention of the present invention is a paper machine installed in a coater, characterized in that the paper that passes through the coater is supplied online to the soft calender. It is.

According to the paper manufacturing method of the present invention, it is possible to prevent the occurrence of soft roll cracks without impairing the quality of the paper and with almost no changes in conventional equipment.

Embodiments of the present invention will be described below.
In general, paper is blended with various types of pulp, such as mechanical pulp, chemical pulp, or deinked pulp (DIP), depending on the application. Although the illustrated paper stock is omitted, the paper stock is supplied to a known paper machine for paper making.
This paper is used as it is depending on the application, or after coating paint chemicals (pigments, adhesives, etc.) from a coater (coating machine) not shown on the paper made by the paper machine, After surface treatment such as smoothness and gloss is performed with a super calender or soft calender, it is wound up with a winder and finished into a desired product.

The present invention relates to a paper manufacturing method in which paper made by a paper machine is subjected to surface treatment such as smoothness and glossiness with a calender, in particular with a soft calender.
In FIG. 1, reference numeral 11 denotes a soft roll, in which a metal core 11a is covered with a hard rubber or plastic covering layer 11b. A heating roll 12 has a heat medium passage (not shown) formed therein, and is heated to about 50 ° C. to 250 ° C.
The soft roll 11 and the heating roll 12 are configured as a pair, and in this embodiment, the soft calender 13 is configured by the two pairs of the soft roll 11 and the heating roll 12 that form a pair.
Needless to say, the soft calendar 13 is not limited to the two sets of the soft roll 11 and the heating roll 12, but may be one set or three or more sets.

  In FIG. 1, reference numeral 14 denotes a slitter, which includes a pair of upper and lower rotary blades 14a and 14b. In addition, this slitter 14 is not limited to what has a pair of upper and lower rotary blades, You may have a rotary blade up or down. 15 is paper.

In the above-described soft calendar 13, as shown in FIG. 1, paper sent online from a paper machine or coater (not shown) is pressed between the soft roll 11 and the heating roll 12 of the soft calendar 13. Passed.
At this time, since the heating roll 12 is heated to about 50 ° C. to 250 ° C. as described above, the gloss of the surface of the paper can be achieved even with a relatively small pressure by the soft roll and the heating roll due to the synergistic effect of the heat and the pressure. It is possible to perform surface treatment such as taking out, and since the paper is not crushed more than necessary, there is an advantage that it is suitable for producing a paper that is bulky and has good printability.

  By the way, generally the full length (full width) 1C of the soft roll 11 is not effective for actual work. Effective surface length 1A (surface length of the soft roll that can apply the set temperature and pressure on the contact surface that pressurizes the paper between the soft roll and the heating roll of the soft calendar) due to the bending of the roll, etc. It is set shorter than the total length 1C of the roll. The soft roll 11 is formed with a coating layer 11b in which the outer periphery of the metal core 11a is coated with hard rubber or plastic. The width of the coating layer 11b is set to be at least longer than the effective surface length 1A. Has been. Normally, the soft roll 11 is covered over the entire length, and both end portions are shouldered and thinned.

Conventionally, the slitter after the soft calendar is not installed as shown in FIG. 3, and the paper width is adjusted by a slitter or the like before the soft calendar 33 in some cases. Therefore, as shown in FIG. 4, the width 3B of the paper 35 passing through the soft calendar 33 is set within the effective surface length 3A.
At this time, a portion of the hard rubber or plastic coating layer 31b covering the outer periphery of the soft roll 31 that faces the heating roll 32 with the paper 35 interposed therebetween is shielded from the heat from the heating roll 32 by more than necessary. However, the soft roll 31 and the heating roll 32 always face each other at the portion beyond the paper width, which may cause a problem. That is, the heat from the heating roll 32 is directly transmitted to the soft roll 31, particularly the hard rubber or plastic coating layer 31 b, and abnormally overheated. It has become.

Therefore, in the present invention, as shown in FIG. 2, the width 1B of the paper 15 passing through the soft calendar 13 is made wider than the effective surface length 1A, and the excess ears are cut off by the slitter 14 at the subsequent stage of the soft calendar 13. ing. For this reason, in the soft calendar 13, the paper 15 is passed over substantially the entire length of the roll exceeding the effective surface length 1A, so that the paper 15 is interposed between the soft roll 11 and the heating roll 12. However, the soft roll 11 and the heating roll 12 hardly face each other, and the heat from the heating roll 12 is directly transmitted to the soft roll 11, particularly the coating layer 11b, and the coating layer 11b becomes abnormal. There is no overheating. For this reason, neither the crack nor the generation | occurrence | production of a crack by the abnormal overheating of the coating layer 11b exists.
The width of the paper to be passed through the soft calendar is 5 to 30 mm wider per side than the effective surface length of the soft roll. This is because if it is narrower than 5 mm, the heat insulation effect of the soft roll and the heating roll may be insufficient, and if it is 30 mm or more, the heat insulation effect reaches its peak.

  Here, if the slitter 14 does not cut off the extra ears and winds up on the reel, the extra part is not applied with the temperature and pressure set by the soft calender. This will cause the unevenness and wrinkles of the reel winding. Therefore, it is more desirable in terms of operation to cut off the excess portion by the slitter 14.

  In addition, after cutting the unnecessary ears at both ends of the paper at the front of the soft calendar, it can be considered that both the product part and the cut-off part are passed through the soft calendar and separated after the calendar process. Is shoulder-dropped (the roll diameter is reduced to a taper shape), and when passing paper, the cut ears will slip if they hit the shoulder drop part of the roll, and the cutting part will be separated, and software that performs high-speed processing online In the calendar, the paper passing through the ear cannot be performed well, which easily causes operational troubles.

As described above, according to the present invention, a simple process change in which the width 1B of the paper 15 passing through the soft calendar 13 is made wider than the effective surface length 1A and an excess portion is cut off by the slitter 14 after the soft calendar 13 is performed. However, since the paper 15 is passed over substantially the entire width of the roll exceeding the effective surface length 1A, the soft roll 11 is provided by the paper 15 being interposed between the soft roll 11 and the heating roll 12. And the heating roll 12 are not directly facing each other, and the coating layer 11b of the soft roll 11 can be prevented from being abnormally overheated by the heat from the heating roll 12, and cracks and cracks due to abnormal overheating of the coating layer 11b can be prevented. Can be prevented.
Therefore, stable operation for a long period of time is possible, and maintenance and inspection are facilitated.

The schematic side view which shows the soft calendar | calender of this invention. FIG. 2 is a front sectional view taken along line X-- in FIG. 1. The schematic side view which shows the conventional soft calendar. FIG. 4 is a front cross-sectional view taken along line Y of FIG. 3.

Claims (4)

  In a paper manufacturing method in which paper made by a paper machine is surface-treated with a soft calender, the width of the paper supplied to the soft calender is made wider than the effective surface length of the soft roll of the soft calender Method.   2. The paper manufacturing method according to claim 1, wherein the width of the paper supplied to the soft calendar is 5 to 30 mm wider per side than the effective surface length of the soft roll of the soft calendar.   The paper manufacturing method according to claim 1 or 2, wherein the edge portions at both ends of the paper are cut by a slitter after the surface treatment with a soft calender and before winding on a reel. 4. The paper manufacturing method according to claim 1, wherein the paper machine installed in the coater supplies paper via the coater to a soft calendar online.

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