JP2004324036A - Staining prevention method for dry part of paper machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a simple method effectively preventing dry part areas, at least the surface of cylindrical dryers, from being stained even without a spray space in a paper machine. <P>SOLUTION: The method for preventing a contact part of a paper body being stained in the dry part D of the paper machine comprises continuous feed/application of a stain inhibitor T to the paper body at a position just before the dry parts. A stain inhibitor film is formed on the paper body by applying the stain inhibitor to the paper body at the position just before the dry parts, and particles of foreign matters are sealed in the paper body. The stain prevention is carried out by the formation of the sealing film on the paper body which inhibits direct contact of the foreign particles to the parts where the paper body contacts, for example on the surface of the cylindrical dryers, and transfer of the particles is inhibited, thus the staining of the cylindrical dryer is prevented. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for preventing contamination of a paper machine, and more particularly, to a method for preventing contamination of a contact portion of a paper body in a dry part of the paper machine.

The paper machine is provided with a drying process based on heating in order to remove moisture, a so-called dry part.
The dry part is equipped with a plurality of cylindrical dryers for drying wet paper and occupies a large part of the paper machine.
In a paper machine, when moisture-containing paper that has not been dried yet is supplied to a dry part, the paper is heated by a cylindrical dryer (usually by passing steam or the like through the inside of the dryer). ) Is pressed against the surface and dried.

Generally, the surface of a cylindrical cylindrical dryer made of metal has a fine rough surface. In particular, since a cast cylindrical dryer is often used, it is inevitable that such a rough surface is generated on the surface.
By the way, the paper contains pitch and tar components contained in the pulp raw material itself, added chemicals contained in various papers, and foreign particles such as filler powder.
Particularly in recent years, waste paper materials have been increasingly mixed into raw materials from the viewpoint of recycling, and in addition, foreign materials such as fine fibers, hot melt, and vinyl acetate-based backing pitch tend to increase. .

When the paper sticks to the surface of the heated cylindrical dryer, the foreign matter powder becomes sticky due to the heat and adheres to the surface, and becomes a contaminant to contaminate the cylindrical dryer.
Such inclusions are more easily adhered to the surface of the cylindrical dryer as they protrude from the surface of the paper.
In order to remove contaminants adhered on the cylindrical dryer, a method of scraping with a doctor blade which is an accessory of the cylindrical dryer is generally used.
However, due to friction between the doctor blade and the dryer surface, the cylindrical dryer surface becomes further rough, and the above-mentioned foreign matter powder enters under the unevenness of the rough surface due to heat and pressure and is fixed.

  As described above, the foreign matter adheres to the cylindrical dryer, and at the same time, the texture on the paper surface is peeled off, so that the foreign matter has a direct or indirect adverse effect.

That is,
1. The thermal conductivity of the surface of the cylindrical dryer decreases, and the drying rate of the paper decreases.
2. The so-called "picking" phenomenon, in which the paper surface peels off, tends to occur.
3. Defects such as the transfer of foreign matter powder grown on the dryer to paper occur.
4. The paper burns on the surface of the cylindrical dryer, causing paper breakage.
5. It may cause irregularities and fluff on the surface of the paper to be produced.
6. Since paper dust is mixed in the product or the surface paper strength is reduced, especially during printing, the paper dust appears as a so-called “white spot” phenomenon that inhibits the transfer of ink to the paper surface.
7. The periodic frequency of cleaning the cylindrical dryer increases, resulting in an increase in cost.
And the like.

For this reason, countermeasures such as using a cylindrical dryer whose surface has been subjected to chrome plating or polytetrafluoroethylene processing in advance, or stopping the machine and periodically performing oil baking treatment are taken. Has been.
However, in both of these measures, if a surface-treated cylindrical dryer is used for a long period of time, the treated surface gradually wears out due to friction, and the effect of preventing contamination is greatly reduced.
Therefore, replacement with a new cylindrical dryer is required, resulting in a loss of replacement time and additional cost.
Therefore, a long-term effect cannot be expected and is not suitable for continuous operation.

For this reason, in the area of the dry part, a method for solving the above-described problems has been adopted by directly and continuously spray-coating the antifouling agent onto the surface of the cylindrical dryer itself. (See Patent Document 1).
Although this method is extremely effective, the space in the dry part area is not always sufficient depending on the type of paper machine.
In some cases, an installation space for disposing a device (spray coating device) for spray-coating the contamination inhibitor cannot be secured.

  In addition, most of the sprays produced by this spray coating device use a method in which the spray nozzle is reciprocated in the axial direction of the cylindrical dryer to apply the anti-pollution agent as uniformly as possible over the entire length of the cylindrical dryer. However, there is a technical limit as a spray coating device, and when the amount of the sticky substance (foreign matter powder) in the raw material increases, a stain may be generated at a portion of the cylindrical dryer where the antifouling agent is cut.

Further, the cylindrical dryer has a relatively large diameter, and it is almost impossible to apply the coating uniformly over the entire cylindrical surface.
In such a state, unevenness occurs in the effect of preventing contamination on the surface of the cylindrical dryer, so that it is not possible to effectively prevent foreign matter powder from sticking, and it is not always a reliable contamination prevention measure.
Further, as described above, the amount of used paper is increasing as a raw material. However, in recent years, used paper contains a large amount of adhesive substances (adhesives, adhesives, and the like) foreign substances, and easily transfers to a cylindrical dryer surface. Tend.

JP-A-2000-96478

The present invention is intended to solve the above problems.
That is, an object of the present invention is to provide a method capable of effectively preventing contamination of the area of the dry part, at least the surface of the cylindrical dryer, in a paper machine in a simple manner and without a spraying space in the paper machine. That is.

  Thus, the present inventors have conducted intensive research on such a problem, and as a result, instead of spray-coating the surface of the dryer with a stain inhibitor, the present inventors have found that the surface of the paper body before entering the cylindrical dryer is applied. It has been found that, by supplying and imparting a contamination inhibitor, it is possible to eliminate a phenomenon in which a contaminant is transferred from a paper body to a portion where the paper body comes into contact, for example, a cylindrical dryer, in the dry part. Was completed.

  That is, the present invention provides (1) a method for preventing contamination of a contact portion of a paper body in a dry part of a paper machine, wherein a stain inhibitor is applied to a paper body in a state before entering the dry part. The present invention resides in a method for preventing contamination of a dry part which is continuously supplied.

  And, (2) the method of continuously supplying and imparting the antifouling agent to the paper body lies in the method of preventing the contamination of the dry part which indirectly applies the paper body to the paper body via an application roller.

  Further, (3) the method of continuously supplying the paper body with the antifouling agent is to indirectly apply the paper body to the paper body via a guide roller, which is included in the method for preventing the contamination of the dry part.

  Further, (4) that the paper body is continuously supplied with the antifouling agent is applied indirectly to the paper body through a felt or a wire, and is included in the method for preventing contamination of a dry part. .

  Further, (5) the method of continuously supplying the paper body with the antifouling agent lies in the method of preventing dry-part contamination by directly applying the paper body using a spray nozzle. .

  Further, (6) a method for preventing contamination of a dry part using oil as a contamination inhibitor.

  Also, (7) a method for preventing contamination of a dry part in which the oil is a mineral oil, a vegetable oil, an animal oil, or a synthetic oil.

  Another aspect of the present invention resides in (8) a method for preventing contamination of a dry part using oil emulsified with a surfactant.

  Further, (9) a method for preventing contamination of a dry part using a polymer as a contamination inhibitor.

  Further, (10) addition polymerization of a mixture as an essential component of a polymer as an antifouling agent comprising a cationic monomer having an ethylenic double bond and an anionic monomer having an ethylenic double bond. The present invention relates to a method for preventing contamination of a dry part which is an amphoteric electrolyte polymer.

  Also, (11) a pollution control agent used in the method for preventing pollution of a dry part according to the above (1), which is obtained by emulsifying a mineral oil, a vegetable oil, an animal oil, or a synthetic oil with a surfactant. In the agent.

  (12) An antifouling agent used in the method for preventing dry part contamination of (1), wherein the cationic monomer having an ethylenic double bond and the anion having an ethylenic double bond A contamination inhibitor which is an ampholyte polymer obtained by addition-polymerizing a mixture containing an amphoteric monomer as an essential component.

  (13) The antifouling agent according to (12), wherein the cationic monomer is a monomer having an amino group, an ammonium base, or a quaternary ammonium base and an ethylenic double bond.

  Further, (14) the contamination inhibitor according to (12), wherein the anionic monomer is a monomer having a carboxyl group or an alkali metal salt thereof and an ethylenic double bond.

  (15) As the cationic monomer, (meth) acrylic acid 2- (N, N-dimethylamino) ethyl methyl chloride salt, (meth) acrylic acid 2- (N, N-dimethylamino) A) methacrylic acid esters such as ethylbenzyl chloride salt and (meth) acrylic acid 3- (N, N-dimethylamino) propylepichlorohydrin hydrochloride and a compound having quaternary ammonium chlorine. The present invention resides in the contamination inhibitor described in (12), which is a combination of one or more kinds (of course, including only one kind).

  (16) Examples of the anionic monomer include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, 2- (meth) acryloyloxyethyl succinate, and 2- (meth) acrylic acid hexahydrophthalate. Oil oxyethyl, and at least one selected from oil oxyethyl (of course, including only one).

  (17) A contamination inhibitor used in the method for preventing contamination of a dry part according to claim 1, wherein the cationic monomer having an ethylenic double bond and the anionic monomer having an ethylenic double bond are used. The present invention resides in a pollution control agent that is an amphoteric electrolyte polymer obtained by addition polymerization of a mixture containing a monomer and a nonionic (nonionic) monomer as essential components.

  (18) As the cationic monomer, 2- (N, N-dimethylamino) ethyl methyl chloride (meth) acrylate, 2- (N, N-dimethylamino) (meth) acrylate A) methacrylic acid esters such as ethylbenzyl chloride salt and (meth) acrylic acid 3- (N, N-dimethylamino) propylepichlorohydrin hydrochloride, and a compound having quaternary ammonium chlorine. The present invention resides in the contamination preventive according to (17), which is a combination of one or more kinds (naturally, including only one kind).

  (19) Examples of the anionic monomer include acrylic acid, methacrylic acid, itaconic acid, fumaric acid, 2- (meth) acryloyloxyethyl succinate, and 2- (meth) acrylic acid hexahydrophthalate. Oil oxyethyl, at least one selected from the group consisting of (of course, only one) is included in the contamination preventive according to (17).

  (20) The non-ionic (nonionic) monomer according to (17), wherein the number of carbon atoms is 6 to 50.

  (21) The contamination inhibitor according to (17), wherein the nonionic (nonionic) monomer is polyethylene glycol mono (meth) acrylate and / or polypropylene glycol mono (meth) acrylate. .

  (22) A method for preventing contamination of a contact portion of a paper body in a dry part of a paper machine, wherein a contamination inhibitor is continuously applied to a paper body in a state before entering the dry part. The present invention is directed to a method for preventing contamination of a dry part, which comprises supplying and supplying a contamination inhibitor continuously to a contact portion of a paper body in the dry part.

  (23) The method for preventing contamination of a dry part according to (22), wherein the contact portion of the paper body in the dry part is a dryer, a canvas, a calender roll, a smoother roll, or a paper roll.

  (24) A contamination inhibitor used for a contact portion of a paper body in the dry part of the above (22), wherein a mineral oil, a vegetable oil, an animal oil, a synthetic oil, or a wax is emulsified with a surfactant. It is a pollution control agent.

  A configuration combining two or more selected from the above 1 to 24 can also be adopted as long as the object of the present invention is met.

[Action]
By continuously supplying and supplying the antifouling agent to the surface of the paper body before entering the dry part, the sealing film is always formed and maintained so as to seal fine foreign particles on the surface of the paper body. You.
By this sealing film, the contact portion of the paper body in the dry part from the paper body, for example, a cylindrical shape

  By supplying and supplying the antifouling agent to the paper body in a state before entering the dry part of the paper machine, a sealing film is formed, and foreign matter powder contained in the paper body is sealed. Due to the formation of the sealing film, since the foreign material powder does not directly contact the portion where the paper body contacts, for example, the surface of the cylindrical dryer, it does not transfer, thereby preventing contamination of the cylindrical dryer. Become.

Since the spray part is not installed in the dry part as in the past, it is possible to prevent contamination of the part where the paper body contacts, for example, the cylindrical dryer, even if there is no extra space for disposing the spray part in the dry part. It is.
Further, unlike the case where the antifouling agent is directly spray-coated on the cylindrical dryer, the application of the antifouling effect can be reliably performed without causing the application unevenness and uncertainty of the antifouling effect.
Further, the paper body in a state before entering the dry part is continuously supplied with the antifouling agent, and further, a contact part of the paper body in the dry part of the paper machine, for example, a dryer, a canvas, a calender roll When the supply is continuously applied to the apparatus, the effect of preventing contamination of the entire apparatus can be further improved.

Hereinafter, the present invention will be described with reference to the drawings and embodiments.
The present invention provides a paper body fed into the dry part of the paper machine by continuously supplying and supplying the antifouling agent to a part where the paper body comes into contact with the dry part, for example, a cylindrical dryer or It can prevent the canvas from being stained.
Even if there is no space for arranging a device for supplying and supplying the pollution control agent to the dryer part, a sufficient effect can be obtained.

FIG. 1 shows a specific example of a method for preventing contamination of a portion where a paper body contacts a dry part of a paper machine of the present invention, for example, a cylindrical dryer.
Normally, the paper machine is provided with a drying part (dry part D) following the press part P. This part includes a heated cylindrical dryer D1... And a canvas K1 for pressing the paper body W against the dryer. .., A canvas roller or the like for guiding the canvas is provided.
The press part P is provided with press rolls P1..., And felts F2.

In the method shown in the figure, a contamination inhibitor T is indirectly supplied via a guide roller 1 to a paper body W in a state before entering a paper machine.
In the case of this figure, an example is shown in which a press roll arranged immediately before entering the dry part is used as a guide roller.

  The guide roller 1 is sprayed with a diluent of the anti-pollution agent T by a spray application device (spray nozzle N), and the anti-pollution agent T attached to the surface of the guide roller 1 is transferred to the paper body W.

At this time, as described later, the contamination preventive agent T is formed as a sealing film T1 for enclosing the foreign matter powder S.
The paper body W to which the antifouling agent T1 has been applied enters the press part P, is pressed and dewatered by the press roll, and then is sent to the dry part D to be heated and dried.

FIG. 2 shows another example in which a roll coater method is used as a means for indirectly supplying and applying the contamination inhibitor T1.
The anti-contaminant T is applied to the paper body W from the anti-contamination agent tank 3 via the application roll 2.

FIG. 3 shows another example in which a felt provided in the press part P is used as a means for indirectly supplying and applying the contamination inhibitor T1.
In this case, a diluting solution of the pollution control agent T1 is applied to the felt F4 installed at the position closest to the dry part D by, for example, a spray nozzle N (so-called spray nozzle) having a full width, and is applied to the paper body W. Transfer.
In this figure, the stain inhibitor T1 is transferred to the rear surface of the paper body W.
The above-described methods of FIGS. 1, 2, and 3 show a method of indirectly supplying and applying the contamination inhibitor T to the paper body W.

The following method shown in FIG. 4 is an example of a method of directly supplying and supplying the paper body W.
The method of supplying and applying the anti-pollution agent here is to supply and apply the diluent of the anti-pollution agent T with a spray nozzle having a full width.
The area where the spray nozzle N is arranged in FIG. 4 and the area where the roll coater is arranged in FIG. 2 are different from a dry part in a normal paper machine, and a relatively sufficient free space is formed. I have.

(Pollution inhibitor)
Now, as a specific antifouling agent used in the present invention, oil or polymer is adopted.
As the oil, for example, mineral oil, vegetable oil, animal oil, synthetic oil (including silicone oil) and the like are suitable.
These may be used alone or in combination.
Since the dryer surface is heated to a high temperature (50 ° C. to 120 ° C.), a type of oil that does not denature at this temperature is selected.

The oil is preferably emulsified in water with the addition of a surfactant to facilitate spraying, as described below.
The mixing ratio of the surfactant is 5 to 70% by weight based on the oil. The specific spraying method depends on the conditions such as the paper making speed, the paper width, and the method of supplying the stain inhibitor. If necessary, a pollution control agent containing 400 to 200,000 times as much water as oil is used.

Further, as described later, the polymer (usually a polymer aqueous solution) needs to have an appropriate adhesive function to a paper body, so that a cationic monomer having an ethylenic double bond is An amphoteric electrolyte polymer obtained by addition polymerization of a mixture containing an anionic monomer having a double bond and an anionic monomer as an essential component is very excellent in antifouling properties and is preferred.
Examples of the cationic monomer having an ethylenic double bond include a monomer having an amino group, an ammonium base, or a quaternary ammonium base and an ethylenic double bond.

Specifically, (meth) acrylic acid 2- (N, N-dimethylamino) ethylmethyl chloride salt, (meth) acrylic acid 2- (N, N-dimethylamino) ethylbenzyl chloride salt, and (meth) acrylic acid A (meth) acrylic acid ester such as acid 3- (N, N-dimethylamino) propylepichlorohydrin hydrochloride and a compound having quaternary ammonium chlorine is used.
From the viewpoint of effectiveness, (meth) acrylic acid 2- (N, N-dimethylamino) ethylmethyl chloride salt and (meth) acrylic acid 2- (N, N-dimethylamino) ethylbenzyl chloride salt are more preferable.

Examples of the anionic monomer having an ethylenic double bond include a monomer having a carboxyl group or an alkali metal salt thereof and an ethylenic double bond. Specifically, acrylic acid, methacrylic acid, itaconic acid, fumaric acid, 2- (meth) acryloyloxyethyl succinate, 2- (meth) acryloyloxyethyl hexahydrophthalate, and the like are employed.
From the viewpoint of effectiveness, acrylic acid and methacrylic acid are more preferable.

Further, to the amphoteric electrolyte polymer described above, a graft chain-like nonionic (nonionic) monomer such as polyethylene glycol mono (meth) acrylate and polypropylene glycol mono (meth) acrylate is added. Addition polymerization is more preferable from the viewpoint of the effect.
As the nonionic (nonionic) monomer, those having 6 to 50 carbon atoms are more preferable from the viewpoint of the effect.
More preferably, those having 10 to 40 carbon atoms show higher effects.
In addition, as the amphoteric electrolyte polymer in the present invention, those in which the cation monomer shows a weight ratio of 40% or more are preferable.

(Pollution prevention principle)
By the way, the antifouling agent T for supplying and supplying to the paper body W in the present invention exerts its original function when the paper body reaches the dry part D by being applied to the surface of the paper body. It is.
That is, it has a function of preventing the foreign matter powder S contained in the paper body W (particularly in a protruding state) from transferring to the dryer surface of the dry part D.

FIG. 5 is a diagram schematically illustrating a cross section of the paper body in a state after the supply of the contamination inhibitor.
The supply of the contamination inhibitor T to the paper body W forms a sealing film T1 that covers and seals the foreign matter powder S that is protruding from the surface of the paper body.
When the paper body W comes into contact with the surface of the cylindrical dryer D, which is a contact portion in the dry part, the foreign matter powder S does not directly come into contact with the dryer surface because the paper body W comes into contact via the sealing film T1.

As described above, since the sealing film T1 exhibits a so-called "shielding effect", the foreign matter S is prevented from being transferred to and fixed to the surface of the cylindrical dryer (see FIG. 5A).
The sealing film T1 having such a shielding function effectively acts on the surface of the cylindrical dryer when oil is used as the contamination inhibitor T.
On the other hand, when the paper body W comes into contact with the surface of the cylindrical dryer D, the sealing film T1 does not peel off because the sealing film T1 exhibits a function of being restrained by the paper body W, that is, an “adhesion function”. As a result of strongly capturing the foreign matter powder S, transfer and fixation to the dryer are prevented (see FIG. 5B).

The latter sealing film T1 having an adhesive function effectively acts on the dryer surface when a polymer is used as the contamination inhibitor T.
It goes without saying that the principle described above can be applied to a canvas.
Here, it is needless to say that the paper body applied in the present invention cannot be applied to a paper machine for manufacturing a tissue since the contamination inhibitor T needs to form a sealing film as described above. .
This is because it is impossible to form a sealing film as in the present invention with a paper quality such as a tissue.

By the way, the supply amount of the anti-contamination agent (eg, oil) may be supplied to such an extent that a thin film is formed so as to seal off foreign matter powder adhering to the paper body.
More specifically, the supply amount of the contamination inhibitor is in the range of 0.00001 to 10 mg / m ^{2 with} respect to the surface of the paper body.
Within this range, it is effective from the viewpoint of preventing adverse effects on the paper quality due to the formation state of the sealing film and the excess film.

[Other Embodiment 1]
As described above, the present invention is characterized in that a paper body in a state before entering the dry part is continuously supplied with the antifouling agent. By continuously supplying the anti-contamination agent to the contact portions (e.g., a dryer, a canvas, a calender roll, a guide roll, etc.), the anti-contamination effect of the entire apparatus can be further improved.
The calender roll is usually arranged at the rearmost part of the dry part, and is a portion for pressing the paper body to improve the smoothness and the like of the surface.

For example, even in the contact part of the paper body in the dry part, particularly, the dryer and the canvas are easily contaminated.
For this purpose, the contamination is prevented by supplying the contamination inhibitor continuously to the dryer or the canvas (it is naturally also possible to supply the contamination to both the dryer and the canvas).

Therefore, as described above in the conventional example, there is a problem that, due to technical limitations of the spray coating device, a portion of the contamination inhibitor is cut off on the cylindrical dryer when the amount of the adhesive substance (foreign matter powder) in the raw material increases. However, there is no problem because the antifouling agent has already been supplied to the paper itself before it enters the dry part.
Here, as the contamination preventive agent to be supplied to the contact portion of the paper body in the dry part, for example, mineral oil, vegetable oil, animal oil, synthetic oil (including silicone oil, etc.), wax, polymer and the like are used. .

In addition, as a means for supplying and supplying to a dryer or a canvas, a spray nozzle or the like as described above is used.
In addition, in order to uniformly spray the antifouling agent over the width of the paper, the antifouling agent is previously diluted with 400 to 200,000 times water and sprayed with a spray nozzle having a full width.

[Other Embodiment 2]
As described above, the present invention is characterized in that the antifouling agent is continuously supplied to the paper body in a state before entering the dry part. A similar effect can be obtained for rolls (paper rolls and smoother rolls) located in the region included in the above.
In this case, the “paper body before entering the dry part” is the “paper body before reaching the paper roll or the smoother roll”.
That is, it is necessary to continuously supply and apply the antifouling agent to the paper before reaching the paper roll or the smoother roll.
By doing so, a sealing film is formed, and foreign matter powder contained in the paper body is sealed.
Due to the formation of the sealing film, the foreign matter powder does not directly contact the surface of the paper roll or the smoother roll, which is the portion where the paper body contacts, and does not transfer, thereby preventing the paper roll and the smoother roll from being contaminated. The Rukoto.

Next, the results of the experiment of spraying the antifouling agent in the present invention will be described.
[Example 1]

In a multi-cylinder dryer-type paper machine (manufactured by Kobayashi Seisakusho Co., Ltd.) as shown in FIG. 1, a pollution control agent is continuously supplied to a paper body (via a press roll P4 in FIG. 1) in a state before entering a dry part. After the coating operation was performed for 8 hours, the surface condition of the dryer (dryer D1 in FIG. 1) at that time was observed.
The quality of the paper (white paperboard in this case) produced during that time was also visually inspected.

(Stain prevention agent used)
The antifouling agent used here is an emulsified aqueous solution (10% concentration, 1.0 g / cc) obtained by mixing a vegetable oil, a surfactant, and water.

(Spray amount)
5 cc / min This amount is previously diluted 1000 times with water and sprayed at 1 L / min.
Here, the area of the passing paper is 200 m ² (paper width: 2 m, paper making speed: 100 m / min), and the supply amount of vegetable oil is 5 cc / min × 1.0 g / cc × 0.1 per unit area. ÷ 200 meters ² / min = a ^{0.0025g / m 2 = 2.5mg / m} 2.

(result)
After a lapse of 8 hours, the dry part was observed. As a result, there was no deposit on the surface of the cylindrical dryer, and the surface showed properties like a mirror surface.
Also, the glossiness of the paper surface is good.
[Example 2]

In a multi-cylinder dryer-type paper machine (manufactured by Kobayashi Manufacturing Co., Ltd.), the operation of continuously supplying and applying the anti-pollution agent to the paper body (via the press roll P4t in FIG. 1) before entering the dry part is performed in eight operations. After the time, the surface condition of the dryer at that time was observed.
In this case, the amount of dirt such as paper dust adhered to the dryer surface (the surface of the dryer D1 in FIG. 1) was measured.
In addition, it is shown that the smaller the value is, the more remarkable the effect of preventing contamination of the surface of the dryer.
Here, the amount of dirt was indicated by an index as 1 when no stain inhibitor was applied to the press roll P4t.
Visual inspection was also performed on the quality of the paper (low-grade printing paper here) produced during that time.

(Spray amount)
3 cc / min This amount is previously diluted 4000 times with water and sprayed at 14 L / min.
Here, the area of the passing paper is 3000 m ² (paper width: 4 m, paper making speed: 750 m / min), and the supply amount of the ampholytic electrolyte polymer is 3 cc / min × 1.0 g / cc × 0. 02 3000 m ² / min = 0.00002 g / m ² = 0.02 mg / m ² .

(Stain prevention agent used)
An experiment was conducted in which a polymer was used as the stain inhibitor used here, and four types of stain inhibitor A, stain inhibitor B, stain inhibitor C, and stain inhibitor D were applied to the paper body.
In addition, 2% polymer aqueous solution was used for the stain inhibitors A to D.
The antifouling agent A is a 2% by weight aqueous solution of a water-soluble polymer containing a polymer of a cationic monomer and an anionic monomer (5: 5 by weight) as a main component. A 2% by weight aqueous solution of a water-soluble polymer mainly composed of a polymer of a monomer and an anionic monomer (weight ratio of 8: 2). It is a 2% by weight aqueous solution of a water-soluble polymer whose main component is a polymer of a monomer and a nonionic monomer (weight ratio of 5: 2: 3).
The stain inhibitor D is a 2% by weight aqueous solution of a water-soluble polymer mainly composed of a polymer of a cationic monomer.

Here, cationic monomer; (meth) acrylic acid 2- (N, N-dimethylamino) ethylbenzyl chloride salt anionic monomer; methacrylic acid nonionic monomer; polyethylene glycol mono (meth) acrylate As a method of applying these antifouling agents to the roll, the above antifouling agents were diluted 4000 times with water and sprayed in a spray nozzle N shown in FIG. It was applied in a proportion.

The results of the above experiment are shown in FIG. 6 (surface state of the dryer).
(result)
After a lapse of 8 hours, the dry part was observed, and as a result, the amount of dirt attached to the surface of the cylindrical dryer D1 was all small, and the antifouling agent C was completely applied to the press roll P4t. It was reduced to 1/10 of the case where there was no case. The smoothness of the surface of the paper produced during this period was also good.

[Other Examples]
The present inventors have conducted an experiment in which a stain inhibitor is indirectly applied to a paper body via a wire in a wire part, and have obtained similar findings.
For reference, the wire part is an area located in front of the press part as shown in FIG.
The wire w is stretched by a guide roll, and the slurry pulp supplied from the head box H is carried on the wire w to the press part in a thin film shape.
At that time, the water contained in the slurry pulp is dehydrated.

Although the present invention has been described above, the present invention is not limited to the embodiment, and it goes without saying that various other modifications are possible without departing from the essence of the present invention.
The present invention is sufficiently applicable as long as the paper body contacts the dry part, and is naturally effective in preventing contamination of the paper rolls for guiding the paper body in addition to the above-described dryer, canvas, and calender roll. There is.
In addition, the dry part is equipped with components such as a paper guide roll, but it is naturally possible to adapt to such components.

Furthermore, as described in the second embodiment, functionally, it is possible to obtain an effect on a roll [that is, a paper roll or a smoother roll (not shown)] in an area substantially included in the area of the dry part. .
In this case, of course, the contamination inhibitor is continuously supplied to the paper body before the paper body reaches the paper roll or the smoother roll.

  The present invention relates to a method for preventing contamination of a dry part in a paper machine. However, the present invention is applicable to the entire papermaking technical field without departing from the principle thereof, and similar effects can be expected.

FIG. 1 shows a specific example of a method for preventing contamination of a cylindrical dryer in a paper machine of the present invention. FIG. 2 shows a case in which a roll coater is used as a means for indirectly supplying and applying a stain inhibitor. FIG. 3 shows another example in which a felt provided in a press part is used as a means for indirectly supplying and applying a stain inhibitor. FIG. 4 shows a case in which a spraying device is used as a means for directly supplying and applying the contamination inhibitor. FIG. 5 is a diagram schematically illustrating a cross section of the paper body in a state after the supply of the contamination inhibitor. FIG. 6 is an experimental result showing the surface condition of the dryer in Example 2. FIG. 7 is a diagram showing a wire part and a press part.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 ... Guide roll 2 ... Application roll 3 ... Contamination inhibitor tank D ... Dry part D1-8 ... Dryer F2-4 ... Felt K1-3 ... Canvas P ... Press part P1-4 ... Press roll W ... Paper body w ... Wire T: Pollution inhibitor N: Spray nozzle

Claims (24)

  A method for preventing contamination of a contact portion of a paper body in a dry part of a paper machine, wherein the paper body in a state before entering the dry part is continuously supplied with an antifouling agent. To prevent contamination of dry parts.   2. The dry part according to claim 1, wherein the step of continuously supplying the antifouling agent to the paper body is performed by indirectly applying the antifouling agent to the paper body via an application roller. Method.   2. The dry part according to claim 1, wherein the step of continuously supplying the paper body with the antifouling agent is performed by indirectly applying the paper body through a guide roller. Method.   The contamination of a dry part according to claim 1, wherein the continuous supply and application of the antifouling agent to the paper body is performed by indirectly applying the paper body with a felt or a wire. Prevention method.   2. The dry part according to claim 1, wherein the step of continuously supplying the antifouling agent to the paper body is performed by directly applying the antifouling agent to the paper body using a spray nozzle. Method.   2. The method for preventing contamination of a dry part according to claim 1, wherein oil is used as the contamination inhibitor.   The method according to claim 5, wherein the oil is a mineral oil, a vegetable oil, an animal oil, or a synthetic oil.   8. The method according to claim 7, wherein the oil is emulsified with a surfactant.   2. The method for preventing contamination of a dry part according to claim 1, wherein a polymer is used as the contamination inhibitor.   Polymer as a pollution control agent is an amphoteric electrolyte polymer obtained by addition polymerization of a mixture containing a cationic monomer having an ethylenic double bond and an anionic monomer having an ethylenic double bond as essential components. The method for preventing contamination of a dry part according to claim 9, wherein:   A contamination inhibitor used in the method for preventing contamination of a dry part according to claim 1, wherein the agent is obtained by emulsifying a mineral oil, a vegetable oil, an animal oil, or a synthetic oil with a surfactant.   An antifouling agent used in the method for preventing contamination of a dry part according to claim 1, comprising a cationic monomer having an ethylenic double bond and an anionic monomer having an ethylenic double bond as essential components. A contamination inhibitor characterized by being an amphoteric electrolyte polymer obtained by addition polymerization of a mixture of the following.   The pollution control agent according to claim 12, wherein the cationic monomer is a monomer having an amino group, an ammonium base, or a quaternary ammonium base and an ethylenic double bond.   The pollution control agent according to claim 12, wherein the anionic monomer is a monomer having a carboxyl group or an alkali metal salt thereof and an ethylenic double bond.   Examples of the cationic monomer include 2- (N, N-dimethylamino) ethyl methyl chloride (meth) acrylate, 2- (N, N-dimethylamino) ethyl benzyl chloride (meth) acrylate, and (Meth) acrylic acid esters such as 3- (N, N-dimethylamino) propylepichlorohydrin hydrochloride and the like, wherein at least one compound selected from compounds having quaternary ammonium chlorine is combined. 13. The antifouling agent according to claim 12, which is present.   The anionic monomer is selected from acrylic acid, methacrylic acid, itaconic acid, fumaric acid, 2- (meth) acryloyloxyethyl succinate, and 2- (meth) acryloyloxyethyl hexahydrophthalate. The pollution control agent according to claim 12, wherein at least one kind is combined.   A stain inhibitor used in the method for preventing contamination of a dry part according to claim 1, wherein the cationic monomer having an ethylenic double bond, the anionic monomer having an ethylenic double bond, and a nonionic (Nonion) A pollution inhibitor characterized by being an amphoteric electrolyte polymer obtained by addition polymerization of a mixture containing a monomer and an essential component.   Examples of the cationic monomer include 2- (N, N-dimethylamino) ethyl methyl chloride (meth) acrylate, 2- (N, N-dimethylamino) ethyl benzyl chloride (meth) acrylate, and (Meth) acrylic acid esters such as 3- (N, N-dimethylamino) propylepichlorohydrin hydrochloride and the like, wherein at least one compound selected from compounds having quaternary ammonium chlorine is combined. 18. The antifouling agent according to claim 17, which is present.   The anionic monomer is selected from acrylic acid, methacrylic acid, itaconic acid, fumaric acid, 2- (meth) acryloyloxyethyl succinate, and 2- (meth) acryloyloxyethyl hexahydrophthalate. 18. The pollution control agent according to claim 17, wherein at least one kind is combined.   18. The antifouling agent according to claim 17, wherein the nonionic (nonionic) monomer has 6 to 50 carbon atoms.   18. The antifouling agent according to claim 17, wherein the nonionic (nonionic) monomer is polyethylene glycol mono (meth) acrylate and / or polypropylene glycol mono (meth) acrylate.   A method for preventing contamination of a contact portion of a paper body in a dry part of a paper machine, wherein the paper body in a state before entering the dry part is continuously supplied with an antifouling agent, and further dried. A method for preventing contamination of a dry part, comprising continuously supplying and imparting a contamination inhibitor to a contact portion of a paper body in the part.   The method for preventing contamination of a dry part according to claim 22, wherein the contact part of the paper body in the dry part is a dryer, a canvas, a calender roll, a smoother roll, or a paper roll.   23. A contamination inhibitor used for a contact portion of a paper body in the dry part according to claim 22, wherein mineral oil, vegetable oil, animal oil, synthetic oil, or wax is emulsified with a surfactant. Pollution inhibitor.

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