JP6998063B2 - Paper manufacturing method - Google Patents

Description

The present invention relates to a method for producing paper .

Conventionally, calendering has been performed to impart smoothness to paper. Calendering is the process of passing paper through metal rolls or between roll pairs consisting of metal rolls and elastic rolls to apply pressure, heat, and friction to the paper to flatten the irregularities on the surface of the paper. , A processing technology that improves smoothness. Such calender processing is performed on grease-removing paper, glassine paper, or the like (Patent Document 1 and Patent Document 2).

Japanese Unexamined Patent Publication No. 11-315500 Japanese Unexamined Patent Publication No. 2009-155758

By the way, in the paper manufacturing process, there is a damping process of adding moisture to the paper and humidifying it after paper making and drying but before the calendering process. Prior to the calender processing, this processing is a processing for the purpose of applying moisture to the paper to raise the moisture content in the paper to some extent and improving the smoothness by the calender processing. The moisture content of the paper after the damping process (mass of water / mass of the entire paper x 100) increases from 5 to 7% before the process to around 20%, and the moisture content in the paper is even after the damping process. It is necessary to keep it in a rolled state for a certain period of time.

That is, from the papermaking process to the calendering process through the damping process, the paper machined paper is dumped (moistized), then rolled into a roll and stored for a certain period of time. After that, the paper is set in the calender device and the calendering process is performed. Therefore, the damping process requires not only the labor of the work but also the storage period after that.

In view of the above circumstances, it is an object of the present invention to provide a method for producing paper, which can omit the damping process prior to the calender process.

The invention of claim 1 has a basis weight (g / m ² ) of 15 or more, contains a saccharide or a sugar alcohol, and has a sugar content (° Bx) of 0.3 or more of the contained saccharide or sugar alcohol. It is a characteristic paper.

The invention of claim 2 is characterized in that the content of the saccharide or sugar alcohol in paper is 0.7 g / m ² or more.
In the invention of claim 3, the paper is a grease-removing paper.

In the invention of claim 4, after papermaking, the paper contains a saccharide or a sugar alcohol, the sugar content (° Bx) of the saccharide or the sugar alcohol is 0.3 or more, and the basis weight (g / m ² ) is 15. It is a paper manufacturing method characterized by the above.

According to the above- mentioned paper manufacturing method, the damping process prior to the calendering process can be omitted.

Schematic diagram of a paper machine.

Hereinafter, an embodiment of paper and a method for producing paper will be described by taking grease-removing paper as an example. In the present embodiment, the grease-removing paper includes not only a finished product that has been calendered, but also an unfinished product that is in the process of being manufactured in a wet paper state, for example.

The grease-removing paper is made of fibers, and it is preferable that the ratio of natural fibers in the total fibers in the grease-removing paper is 50% by mass or more. If the proportion of natural fibers is less than 50% by mass, the removability of grease when used as a grease-removing paper may decrease. Natural fibers include plant fibers or animal fibers, and plant fibers include fibers taken from seeds such as cotton, fibers taken from fruits such as koiya, fibers taken from leaves such as Manila hemp and sisal hemp, flax, yellow hemp, and 楮. , Mitsumata, fibers from stems and bark such as bast, and wood pulp of broadleaf and coniferous trees. Wood pulp includes kraft pulp and mercerized pulp, and pulp includes bleached pulp and unbleached pulp that has not been treated. Animal fibers include wool, silk, cashmere and the like. As the fiber used for the grease removing paper, it is preferable to use softwood bleached kraft pulp (NBKP) or Manila hemp from the viewpoint of cost, smoothness and the like.

Other fibers that can be used in combination with natural fibers include recycled fibers such as viscose rayon and cupra, semi-synthetic fibers such as acetate and promix, and synthetic fibers such as polyester, nylon, polyethylene, vinylon, and polypropylene. There are fibers. It is preferable that the plant fiber used for the grease-removing paper is adjusted to a predetermined beating degree, for example, SR 15 degrees to 40 degrees by a beating machine such as a beater.

It is preferable that the grease-removing paper contains an inorganic filler such as clay, talc, kaolin, calcium carbonate, etc. in order to enhance the liposuction property, in addition to the fiber as a raw material, and further, a fixing agent, an antibacterial agent, a fragrance, a coloring agent, etc. Can also be contained. It is preferable that these are contained in the grease-removing paper by a method of adding them together with the fiber raw material in the papermaking tank at the time of papermaking.

In addition, the grease-removing paper needs to contain sugars or sugar alcohols. Since the grease-removing paper contains sugar or sugar alcohol, even if it is calendered without damping processing, it does not contain sugar or sugar alcohol, and is the same as the damping-processed and calender-processed grease-removing paper. Smoothness can be achieved. The sugar content (unit: ° Bx) of the sugar or sugar alcohol contained in the grease-removing paper needs to be 0.3 or more. If the sugar content is less than 0.3, the smoothness of the grease-removing paper may not be improved when the calendering process is performed without the damping process. The sugar content of the sugar or sugar alcohol contained in the grease-removing paper can be measured by the method described in the examples.

The saccharides include monosaccharides such as glucose, fructose and galactose, and disaccharides such as sucrose, lactose, malt and trehalose sugar.
The sugar alcohol is a kind of sugar produced by reducing the carbonyl group of aldose or ketose, and includes erythritol, glycerin, isomalt, lactitol, maltitol, mannitol, sorbitol, xylitol, artitol and the like.

As the sugar or sugar alcohol, one of them may be used alone, or a plurality of different types may be mixed and used, and the mixing ratio thereof is not limited.
As a method of containing saccharides or sugar alcohols in the grease-removing paper, a method of applying the saccharides or sugar alcohols to the grease-removing paper after forming the wet paper and before drying can be adopted. When the sugar or sugar alcohol is a powder, it is preferably applied as an aqueous solution. In addition to the spraying device, a roll coater can be used to apply sugar or sugar alcohol. The timing of adding the sugar or sugar alcohol to the grease-removing paper is not limited to before the grease-removing paper is dried, but may be after drying or before the calender processing.

The basis weight (mass per square meter) of the grease-removing paper needs to be 15 g / m ² or more. If the basis weight is less than 15 g / m ² , the paper itself becomes thin, and tearing may occur during calendering. The basis weight is the mass including sugars or sugar alcohols contained in the grease-removing paper.

Hereinafter, an embodiment of a method for producing grease-removing paper will be described with reference to FIG. FIG. 1 is a schematic diagram of a paper machine 1. This paper machine 1 is a so-called circular net paper machine provided with one circular net, and has the same basic configuration as the conventional one. In the paper machine 1 of FIG. 1, the outline and the papermaking process proceed from the left side in the figure to the right side, so the left side in the figure is also referred to as upstream and the right side is also referred to as downstream. The paper machine 1 is roughly divided into a wet part W which is arranged on the upstream side and where the wet felt 2 runs, and a dry part D which is arranged on the downstream side and dries the wet paper P.

The wet part W is composed of a wet felt 2, a paper tank 3, a cylindrical cylinder 4, a couch roll 5, a press roll 6, and a plurality of guide rollers. A cylindrical cylinder 4 is rotatably arranged inside the paper tank 3. A head box 7 is arranged on the most upstream side of the paper machine 1, and a pipe for supplying paper charges extends from the head box 7 to the paper machine 3 (not shown). A small-diameter couture roll 5 is arranged on the upper part of the cylindrical cylinder 4. The couture roll 5 is for pressing the wet felt 2 against the upper surface of the cylindrical cylinder 4.

The wet felt 2 is a blanket formed in an endless shape, picks up the wet paper P formed on the surface of the cylindrical cylinder 4, and conveys the wet paper P to the dry part D. The wet felt 2 is driven by a drive mechanism (not shown), and the cylindrical cylinder 4 is driven by the drive of the wet felt 2 and rotates clockwise in the figure.

The dry part D is composed of a press roll 6, an endless dry felt 8, a touch roll 9, a Yankee dryer 10, and a plurality of guide rollers. Further, an coating device 11 is arranged upstream of the Yankee dryer 10 so as to face the wet paper P on the dry felt 8, and is located in the width direction of the wet paper P on the dry felt 8 from the spray nozzle 12 of the coating device 11. It is possible to spray sugar or sugar alcohol as a liquid throughout.

By continuously spraying the wet paper P on the moving dry felt 8 with a liquid from the coating device 11, the wet paper P can contain the sugar or the sugar alcohol.

Hereinafter, examples will be specifically described.
NBKP 100% was used as a fiber raw material for the grease-removing paper, and this was beaten with a beater to adjust the SR to 18 degrees and used as a raw material for producing the grease-removing paper in each test example.

A single layer of grease-removing paper was produced using the same raw material. As shown in Table 1, a plurality of types of grease-removing papers having different basis weights when used as grease-removing papers were manufactured. The basis weight of the grease-removing paper shown in Table 1 is the mass in a state containing sugars or sugar alcohols as described above.

After dehydrating the produced grease-removing paper and before drying, sugar or sugar alcohol was applied to one side of the grease-removing paper by spraying. Table 1 shows the types of saccharides or sugar alcohols to be applied to the grease-removing paper and the amount (g / m ² ) of the saccharides to be applied. Glycerin, sorbitol, xylitol, and sucrose were used as sugars or sugar alcohols.

As the glycerin, Miyoshi Oleochemical Co., Ltd. purified glycerin (concentration 99% or more, liquid at room temperature) was used. As sorbitol, Bussan Food Science Co., Ltd., sorbitol S (concentration 70%, liquid at room temperature) was used. As xylitol, product Food Science Co., Ltd. xylitol (powder at room temperature) was used. As sucrose, Pearl Ace Co., Ltd.'s white sugar (powder at room temperature) was used.

Since glycerin and sorbitol are liquids at room temperature, they were applied to the grease-removing paper as liquids. On the other hand, since xylitol and sucrose are powders at room temperature, they were applied to grease-removing paper as an aqueous solution in which the powders were dissolved. The coating amount shown in Table 1 is an amount obtained by converting a saccharide or a sugar alcohol into a 100% by mass concentration, respectively.

After applying sugar or sugar alcohol to the grease-removing paper, it was dried and calendered without damping to obtain the grease-removing paper of each test example. For the calender processing, a thermal calender device having a roll pair pair manufactured by Yuri Roll Co., Ltd. was used, and the conditions for the calender processing were a temperature of 100 ° C., a linear pressure of 100 kg / cm, and a processing speed of 1 m / min.

The thickness, density, sugar content, and smoothness of each test example after the calender processing were measured. The density is a value calculated from the basis weight and the thickness. However, in Test Example 8, the basis weight was as small as 10 g / m ² , and it was judged that it could not be used because it was torn during the calendering process, and the thickness and density were not measured.

For the sugar content test of the test example, a digital sugar content meter PR-1 manufactured by Atago Co., Ltd. was used. To measure the sugar content (° Bx), 0.5 ml of water is dropped on the concave measuring part of the sugar content meter, and a cut piece cut into 5 cm × 5 cm is placed on the dropped water and left for 5 seconds. To suck. After that, the cut pieces were squeezed with a finger, and the juice was dropped onto the measuring part of the sugar content meter, and the sugar content of the juice was measured. That is, 0.5 ml of water is dropped on the measuring part of the sugar content meter, and a cut piece of grease-removing paper cut into 5 cm × 5 cm is placed on the dropped water and left for 5 seconds to absorb the water. The sugar content of the juice of one piece is the sugar content of the sugar or sugar alcohol contained in the fat removing paper.

The smoothness (in seconds) was measured based on "Paper and Paperboard-Smoothness Test Method Using Beck Smoothness Tester" specified in JIS P8119.
In addition, as a reference example, papermaking is performed using only the same fiber raw materials as in the test example, dried without applying sugars and sugar alcohols, dumped, and then calendered to produce grease-removing paper. did. In this reference example as well, multiple patterns with different basis weights were created corresponding to the test examples. However, since the standard example does not contain sugars and sugar alcohols, its basis weight is the mass of the fiber raw material only.

The method of damping is to make a standard example of grease-removing paper, dry it, spray water so that the moisture content of the grease-removing paper becomes 18%, and then cover the entire grease-removing paper with a wrap to evaporate the water. It was left at room temperature for 24 hours so as not to prevent it.

In addition, after the damping process of the standard example, the calender process was performed under the same conditions as the test example. The thickness, density, and smoothness of each reference example after calender processing were measured by the same method as in the test example. In addition, the smoothness of Test Example 13 and Reference Example 3 before calender processing was also measured, and it was confirmed that the smoothness of both was approximately the same. Table 1 shows the results of the test examples and the reference examples.

基準例１ないし５の脂取り紙では、ダンピング加工とキャレンダー加工との双方の加工を経た後の平滑度が坪量にかかわらずおおよそ４００であった。そして、糖類又は糖アルコールを含有させた脂取り紙の平滑度がこの数値（４００）を超えていれば、ダンピング加工をしなくてもキャレンダー加工のみで基準例と同等の平滑度が達成できていることとなる。

In the grease-removing papers of Standard Examples 1 to 5, the smoothness after both the damping process and the calender process was about 400 regardless of the basis weight. If the smoothness of the grease-removing paper containing sugar or sugar alcohol exceeds this value (400), the smoothness equivalent to that of the standard example can be achieved only by the calendering process without the damping process. It will be.

Among the test examples, some test pieces having a sugar content of less than 0.3 or less than sugar alcohol contained in the grease-removing paper were calendered without dumping and had a smoothness of less than 400, and dumping was performed. It did not reach the standard example of processing. Those with a sugar content of 0.3 or more had a smoothness of more than 400 after calendering regardless of the basis weight, and this smoothness tended to increase as the sugar content increased.

From the above results, if the sugar content of the sugar or sugar alcohol contained in the grease-removing paper is 0.3 or more, even if it is calendered without dumping, it is equal to or higher than the standard example that has been dumped. Smoothness was achieved. Therefore, the damping process prior to the calender process can be omitted.

This paper and the method for producing paper are not limited to grease-removing paper, and can be applied to glassine paper, gravure paper, etc., which have been subjected to damping processing and calendering processing.
Regarding the sugar content, when the fat-removing paper contains sugar or other substances that affect the sugar content in addition to sugar alcohol, the sugar content of the fat-removing paper containing sugar or sugar alcohol and other substances is the same. , The sugar content of the sugar or sugar alcohol contained in the fat-removing paper can be specified by the difference from the sugar content of the fat-removing paper containing the same other substance and not containing sugar or sugar alcohol.

When the sugar content of sugar or sugar alcohol contained in the grease-removing paper is in the range of 0.3 or more from the viewpoint of the amount of sugar or sugar alcohol applied, the amount of sugar or sugar alcohol applied is 0. It is preferably 7 g / m ² or more.

1 ... Paper machine, 2 ... Wet felt, 3 ... Paper machine, 4 ... Cylindrical cylinder, 5 ... Couch roll, 6 ... Press roll, 7 ... Headbox, 8 ... Dry felt, 9 ... Touch roll, 10 ... Yankee dryer, 11 ... coating device, 12 ... spray nozzle.

Claims (2)

A process of forming wet paper from fibers containing 50% by mass or more of plant fibers as a raw material.
The process of adding sugar or sugar alcohol to the wet paper,
A method for producing paper, which comprises a step of drying the wet paper containing the same sugar or sugar alcohol and performing a calendering process without dumping.
The paper is characterized by having a sugar content (° Bx) of 0.3 or more, a basis weight (g / m ² ) of 15 or more , and a smoothness of 400 seconds or more according to the following measuring method. Manufacturing method.
(Measurement method) 0.5 ml of water is dropped on the measuring part of the sugar content meter, and a cut piece of paper cut into 5 cm x 5 cm is placed on the dropped water and left for 5 seconds to absorb the water. The sugar content (° Bx) measured by the sugar content meter for the sugar content of one piece of juice. In the step of incorporating sugar or sugar alcohol into the wet paper, 0.7 g / m of sugar or sugar alcohol is added to the wet paper. ² The method for producing paper according to claim 1, wherein the above is applied.

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