JP4682274B2 - Identification method for paper product deposits - Google Patents

Description

  The present invention relates to a paper product deposit identification method capable of determining in a short time whether or not slime is contained in deposits that cause troubles such as degradation of paper product quality and production efficiency.

  In the papermaking process of a papermaking factory, pulp is dispersed and suspended in water, the pulp concentration is adjusted to a constant level, various papermaking chemicals are added, and papermaking is performed by a papermaking machine to produce a paper product. This papermaking process includes a pulp raw material system, a waste paper system, a preparation system, a white water circulation system, a white water recovery system, and the like.

  The most serious problem in the quality control of paper products in paper mills is that some foreign matter adheres to the paper during paper making, and this deposit generates defective parts called holes, spots, and eyeballs on the paper product. . Such a defective portion not only greatly reduces the quality of the paper product, but also causes paper breakage, making continuous operation of the paper machine difficult and significantly reducing production efficiency. Also, the defective part causes various troubles in printing of paper products.

It is known that the deposits of paper products are organic and inorganic substances such as slime, pitch, scale, size, and foreign substances, and composites thereof. Slime is composed of microorganisms such as bacteria, fungi, yeasts, and sticky substances produced by them. Among the papermaking processes, the papermaking process is in an environment where microorganisms are likely to grow. Therefore, in the papermaking process, a slime control process is usually performed to suppress the generation of microorganisms.
In the slime control treatment, usually, after determining whether or not slime is contained in the deposit of the paper product, when slime is contained, the slime control agent is added, or the slime control agent is already added. If the drug is present, it is performed by changing the type of the drug or increasing the amount of the drug added.

Conventionally, the above determination is performed using microscopic observation, a spectrophotometer method, a ninhydrin reaction, an IR (FT-IR: Fourier transform infrared spectroscopy) method, or the like.
In the microscopic observation, the deposit itself is visually observed with a microscope to determine whether or not the deposit contains slime. This determination requires the skill of an observer, the time required for the determination and the time required for the determination. There is a problem with accuracy.

  In the spectrophotometer method, the base of the nucleic acid of the microorganism is extracted from the deposit, the UV absorption of the extract is measured with a spectrophotometer, and whether the deposit contains slime depending on the presence or absence of maximum absorption near 260 nm. It has the feature that it can be determined relatively easily. However, in this determination method, when used paper is used as a pulp raw material, it is impossible to determine whether or not slime is included because paper products and paper products containing lignin have UV absorption that does not originate from microorganisms in the vicinity of 280 nm. There is a problem.

  The ninhydrin reaction is a method using ninhydrin that reacts with a compound having an amino group at the α-position, such as a microorganism, and develops a slime. Whether or not it is included is determined, and has a feature that it can be easily determined in a short time. However, this determination method has a problem that there is a possibility of misjudgment because it is low in sensitivity and develops color even for compounds having an amino group at the α-position other than microorganisms.

  The IR (FT-IR) method is for determining whether or not the deposit contains slime depending on the presence or absence of a specific spectral pattern of an aliphatic secondary amide such as a microorganism. However, there is a problem that there is a possibility of misjudgment when a compound having a similar spectral pattern is mixed with an adhering substance other than microorganisms.

  Japanese Patent Laid-Open No. 2003-164281 (Patent Document 1) discloses a method for analyzing an adhering substance by extracting DNA derived from a microorganism from the adhering substance and using the obtained DNA base sequence as an index. A method for analyzing microflora or dominant microorganisms is disclosed. In this analysis method, the type of microorganism is specified.

However, the analysis method described in the above publication requires an advanced analytical instrument.
On the other hand, when identifying the deposits of paper products and determining whether or not the addition of the slime control agent is necessary from the result, it is not necessary to know the type of microorganism, and it is sufficient to determine the presence or absence of slime. For this reason, the analysis method described in the above publication is excessive analysis and is not preferable because it takes time to obtain the final determination result.
Therefore, a method for determining in a short time whether or not slime is contained in the paper product deposit in the papermaking process has been desired.

JP 2003-164281 A

  The present invention provides a method for determining in a short time whether or not slime is contained in a paper product deposit in a papermaking process, using a combination of an inexpensive drug and a simple device, without depending on an advanced analytical instrument. This is the issue.

  In order to solve the above-mentioned problems, the inventors of the present invention have conducted intensive research by paying attention to the base component of the nucleic acid of the microorganism contained in the paper product deposit in the papermaking process. As a result, when the adhering substance is treated with an acid, the cell wall of the microorganism contained in the adhering substance is destroyed to extract the nucleic acid, and when the base in the nucleic acid is liberated, the purine base is the pyrimidine base in the base. In order to complete the present invention, it has been found that the presence of slime in the deposit can be more easily determined by confirming the presence of the released purine base. Arrived.

Thus, according to the present invention, the paper product deposits in the papermaking process are treated with acid, and the peripheral portions of the deposits are similarly treated with acid to obtain a treatment solution and a control treatment solution, respectively.
The obtained treatment liquid and the control treatment liquid were subjected to high performance liquid chromatography (HPLC) analysis with a measurement wavelength of 250 to 280 nm,
In contrast to the HPLC analysis results obtained, the following two criteria:
(1) In the HPLC analysis of the treatment liquid, a pair of absorption peaks of purine bases guanine and adenine are present at the same intensity around a wavelength of 260 nm.
(2) The intensity of (1) is at least twice the average intensity of the absorption peak at the retention time corresponding to guanine and adenine in the HPLC analysis of the control treatment solution.
When satisfying, it is determined that the deposit contains slime,
When the criterion (1) is not satisfied, it is determined that the deposit does not contain slime, and a paper product deposit identification method is provided.

According to this invention, it is possible to determine in a short time whether or not slime is contained in a paper product deposit in a papermaking process, using a combination of an inexpensive drug and a simple device, without depending on an advanced analytical instrument. it can.
Therefore, according to the present invention, when a defective portion occurs in a paper product in a paper mill, it is determined in a short time whether or not slime is contained in the deposit on the defective portion, and a chemical addition such as a slime control agent is added. Therefore, it is possible to reduce the decrease in production efficiency in the paper making process.

In the paper product deposit identification method of the present invention, the paper product deposit in the papermaking process is treated with an acid, and the presence of a purine base in the treatment liquid is analyzed to determine whether the deposit contains slime. It is characterized by determining.
Microorganisms contained in the slime include DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) constituting a gene, and these include purine bases (adenine, guanine) and / or pyrimidine bases (cytosine, thymine, uracil). In this invention, the presence or absence of purine bases is analyzed.

Although it does not specifically limit as a paper product in this invention, For example, a newspaper, OA paper, a corrugated cardboard, packaging paper, a film, tissue paper, toilet paper, a paper towel, a napkin, a paper diaper etc. are mentioned.
The paper product deposit in the present invention means a spot portion of a paper product in which a defective portion called a spot is generated in the paper making process.

In the paper product deposit identifying method of the present invention, first, the paper product deposit in the paper making process is treated with an acid.
This treatment liberates the base in the nucleic acid of the microorganism. As a method for liberating a base in this manner, various methods such as physical treatment such as ultrasonic crushing and freeze-thaw method, chemical treatment with acid, enzyme, surfactant, etc. are known. Then, the deposit is treated with an acid.
Examples of the treatment with an acid include a treatment of heating the deposit in the aqueous solution using an acid such as perchloric acid (HClO ₄ ), hydrochloric acid (HCl), formic acid (HCOOH), or the like.

The acid concentration in the above treatment may be appropriately set depending on the state of the deposit, etc., but is usually about 3 to 6 mol / l.
Moreover, although the quantity of the acid to be used is based also on the density | concentration of an acid, it is about 5-20 ml with respect to 10 mg of paper products samples containing a deposit.

The heating temperature in the above treatment is about 70 to 100 ° C., and the heating time is about 30 minutes to 2 hours. The heating method is not particularly limited, and heating by a water bath, an oil bath or the like can be mentioned.
Further, in the above treatment, DNA extraction and base isolation can be promoted by subdividing the adhered sample.
As an example of the treatment with acid, an aqueous perchloric acid solution is added to a sample of a paper product deposit, the sample is loosened (subdivided), and heated in a water bath at 90 to 100 ° C. for 1 hour.

Next, the presence of purine base in the treatment solution is analyzed.
The analysis method is not particularly limited, and a UV detector is provided at a measurement wavelength of 250 to 280 nm for a treatment liquid obtained by treating a paper product deposit with an acid and a control treatment solution obtained by treating a peripheral portion of the deposit with an acid. It is particularly preferable to analyze the presence of the purine base in the treatment liquid by performing high performance liquid chromatography (HPLC) analysis and comparing the obtained analysis results. According to this analysis method, it is possible to determine in a short time whether or not the deposit contains slime. In addition, the method of processing the peripheral part of a deposit | attachment with an acid is the same as the processing method of a deposit | attachment.

The above measurement wavelength region is a purine base absorption region, and if it is outside this region, the purine base detection sensitivity is lowered, which is not preferable.
A known apparatus can be used for this HPLC analysis.

By comparing the obtained analysis results, it is determined whether or not the deposit contains slime according to the following criteria.
(1) When the deposit contains slime In the HPLC analysis of the treatment liquid, a pair of absorption peaks of the purine bases guanine and adenine are present in the vicinity of a wavelength of 260 nm with the same intensity, and the intensity is the same as that of the control treatment liquid. It is more than twice the average intensity of the absorption peak at the retention time corresponding to guanine and adenine in HPLC analysis.

(2) When the deposit does not contain slime The obtained analysis result does not satisfy the above criterion (1).
For example, the following modes can be considered.
A pair of absorption peaks of the purine bases guanine and adenine are present at the same intensity around a wavelength of 260 nm, but the intensity does not satisfy the above criterion (1).
Only the absorption peak of one of the purine bases guanine and adenine exists in the vicinity of a wavelength of 260 nm.
Absorption peaks corresponding to purine bases guanine and adenine do not exist in the vicinity of a wavelength of 260 nm (absorption peak is in the noise region).

In the paper product deposit identification method of the present invention, when it is determined that the deposit contains slime, it is promptly dealt with by slime control treatment such as addition of a slime control agent.
In addition, when it is determined that the deposit is not derived from slime, the deposit may be promptly determined by another identification method.

(Example)
The present invention will be described in detail by test examples, but the present invention is not limited by these test examples.

Test Example 1 (Slime judgment test)
A mobile phase for buffer and high performance liquid chromatography (HPLC) was prepared in advance.
Specifically, 3.0 ml of phosphoric acid and 7.1 g of disodium hydrogen phosphate (anhydrous) were added to a 300 ml glass beaker, and 250 ml of water was further added to obtain a buffer solution.
Further, 36.75 g of sodium chlorate and 1 ml of phosphoric acid were dissolved in pure water to make 1000 ml, thereby obtaining a mobile phase.

A paper mill B machine (corrugated cardboard paper machine) scraped adhering material adhering to the corrugated cardboard paper (adhered material sample), 4w / w% pulp slurry and increased wet paper strength in use at the same factory The agent was obtained.
As a result of microscopic observation, it was found that the adherent sample was mainly composed of bacteria-derived slime.
The pulp slurry was diluted to 1 w / v% with Osaka city water and the deposit sample was added. The obtained pulp slurry is paper-made with a hand-making machine, pressed at a pressure of 3.5 kg / cm ² , dried at 105 ° C. for 10 minutes, and a sheet on which foreign matter (adhered matter) is made in the center is formed. Obtained.
The test was performed on the part where the foreign material was incorporated (abnormal part) and the peripheral part (normal part).

The abnormal part and the normal part were sampled in the same amount, cut with scissors, and used as samples.
First, about 10 mg (± 0.5 mg) of each sample was put into a 10 ml Teflon (registered trademark) test tube, 4 ml of 3.3 mol / l perchloric acid aqueous solution was added, and the paper was loosened with a glass rod. Next, each test tube was heated in a 90-100 ° C. water bath for 1 hour.
Thereafter, 2 ml of a 6 mol / l sodium hydroxide aqueous solution was added to each test tube, and the mixture was adjusted with a 2.5 mol / l sodium hydroxide aqueous solution so that the pH was about 2. Furthermore, 1 ml of a buffer solution prepared in advance was added, and a 0.25 mol / l sodium hydroxide aqueous solution was added until the mixture became pH 4.5 to 5.0.

Thereafter, the mixture of test tubes was placed in a 10 ml glass measuring flask, and pure water was added to make the volume 10 ml. The obtained mixed solution was centrifuged at a rotational speed of 1000 rpm for 5 minutes, and the resulting supernatant was analyzed by HPLC under the following conditions.
The analysis results of the abnormal part and the normal part (comparison) are shown in FIGS. 1 and 2, respectively.
Moreover, the measurement result of HPLC using each reagent of cytosine, uracil, guanine, adenine, and thymine is shown in FIG.

(conditions)
Column: ODS column Flow rate: 0.5 ml / min Wavelength: 260 nm
Measurement time: 15 minutes

The absorption peaks at retention times 5.48, 6.89, 9.94, 10.82 and 16.33 in FIG. 3 correspond to cytosine, uracil, guanine, adenine and thymine, respectively.
Since the peaks at retention times 9.94 and 10.82 are the purine bases guanine and adenine, the charts of FIG. 1 and FIG. 2 are compared focusing on these peaks.

In FIG. 2 (normal part), the absorption peaks corresponding to guanine and adenine are in the noise region, whereas in FIG. 1 (abnormal part), the absorption peaks corresponding to guanine and adenine are stronger than the noise level. And the intensity is at least twice the average intensity of the absorption peak at the retention time corresponding to guanine and adenine in the analysis of the normal part.
From these results, it can be seen that whether or not the deposit contains slime can be determined according to the following criteria.

(Standard)
(1) The deposit contains slime In the HPLC analysis of the treatment liquid, a pair of absorption peaks of the purine bases guanine and adenine are present in the vicinity of a wavelength of 260 nm, and the intensity is the HPLC of the control treatment liquid. It is at least twice the average intensity of the absorption peak at the retention time corresponding to guanine and adenine in the analysis.
(2) The slime is not included in the deposit. The obtained analysis result does not satisfy the above criterion (1).

Comparative Test Example 1 (Slime judgment test by microscopic observation)
The abnormal part and normal part of the sheet prepared in Test Example 1 were scraped off with tweezers to obtain a sample. Each obtained sample was observed with a microscope at a magnification of about 150 to 300 times.

  If slime is present in the microscopic observation, bacterial cells, mold spores, hyphae, etc. are directly observed. Although the presence of foreign substances could be confirmed in the observation of the abnormal part, the cells and spores could not be discerned because the slime was altered by pressing and drying.

Comparative Test Example 2 (Slime judgment test by spectrophotometer method)
The abnormal part and the normal part of the sheet prepared in Test Example 1 were sampled in the same amount, cut with scissors, and used as samples.
First, about 10 mg (± 0.5 mg) of each sample was put into a 10 ml Teflon (registered trademark) test tube, 4 ml of 3.3 mol / l perchloric acid aqueous solution was added, and the paper was loosened with a glass rod. Next, each test tube was heated in a 90-100 ° C. water bath for 1 hour.
The obtained mixed solution was centrifuged at 1000 rpm for 5 minutes, and the intensity of the spectrum at a wavelength of 200 to 340 nm of the supernatant obtained by a spectrophotometer was measured.

If slime is present in the spectrophotometer method, the maximum absorption (near wavelength 260 nm) of the base component of the nucleic acid is measured.
In the measurement of the abnormal part and the normal part, the maximum absorption at a wavelength of 280 nm was measured, and slime could not be discriminated and could not be judged. The maximum absorption at a wavelength of 280 nm coincides with the absorption of lignin contained in the pulp.

Comparative Test Example 3 (Slime judgment test by ninhydrin reaction)
The ninhydrin reagent was dissolved with 1-butanol so as to have a concentration of 0.3 w / v% to obtain a ninhydrin solution.
The abnormal part and normal part of the sheet prepared in Test Example 1 were scraped off with tweezers to obtain a sample. Each of the obtained samples was well adapted to the ninhydrin solution, and these were heated at 105 ° C. for 5 minutes and observed.

If slime is present in the ninhydrin reaction, the sample turns purple.
Naturally, the purple color cannot be confirmed by observing the normal part, but the purple color can hardly be confirmed even by observing the abnormal part. The factors that resulted in this were as follows: the ninhydrin solution did not sufficiently permeate inside the pulp fiber, the deposit itself was dispersed in the paper making process, and the concentration of the deposit was below the concentration at which coloration occurred in the ninhydrin reaction. It is thought that it became.

Comparative Test Example 4 (Slime judgment test by FT-IR method)
The abnormal part and normal part of the sheet prepared in Test Example 1 were scraped off with tweezers to obtain a sample. Each obtained sample was placed on a stage of a spectroscope and pressed to measure the intensity of the infrared absorption spectrum. Infrared absorption spectra were also measured for polyamide, polyamine, and epichlorohydrin resins, which are wet paper strength enhancers used in corrugated board paper machines.

If slime is present in the FT-IR method, specific spectral patterns of aliphatic secondary amides (around 3200-3300, 2900, 1650, and 1540 cm ⁻¹ ) are measured.
When comparing the normal part and the abnormal part, absorption of the aliphatic secondary amide having a specific absorption pattern was observed only in the abnormal part. On the other hand, the wet paper strength enhancer showed the absorption of the aliphatic secondary amide as in the abnormal part. For this reason, it could not be determined whether the causative substance of the deposit was due to slime or wet paper strength enhancer.

Test Example 2 (Determination test for spotted slime on medium paper)
A slime determination test was performed on the spots generated by the C paper mill No. D (medium paper machine).
The same amount of the spot portion (abnormal portion) and the surrounding portion (normal portion) were sampled, and the presence or absence of slime in the spots was determined in the same manner as in Test Example 1.
The analysis results of the abnormal part and the normal part (comparison) are shown in FIGS. 4 and 5, respectively.

In FIG. 5 (normal part), an absorption peak close to guanine is observed at a retention time of 8.73, but no absorption peak corresponding to adenine is observed near a retention time of 9.5 to 10.0.
On the other hand, in FIG. 4 (abnormal part), a pair of absorption peaks corresponding to guanine and adenine are observed at retention times 8.69 and 9.77, respectively, and their intensities correspond to guanine and adenine in the analysis of the normal part. It is at least twice the average intensity of the absorption peak at the retention time.
From this, it can be determined that the abnormal portion contains slime.

Test Example 3 (Determination Test for Spotted Slime Generated on Middle and Lower Grade Paper)
A slime judgment test was conducted on the spots generated in the E paper mill No. F (intermediate lower grade paper machine).
The same amount of the spot portion (abnormal portion) and the surrounding portion (normal portion) were sampled, and the presence or absence of slime in the spots was identified in the same manner as in Test Example 1.
The analysis results of the abnormal part and the normal part (comparison) are shown in FIGS. 6 and 7, respectively.

In FIG. 7 (normal part), absorption peaks corresponding to guanine and adenine are observed at retention times 8.78 and 9.84, respectively.
On the other hand, in FIG. 6 (abnormal part), a pair of absorption peaks corresponding to guanine and adenine are observed at retention times 8.78 and 9.85, respectively, and their intensities correspond to guanine and adenine in the analysis of the normal part. It is at least twice the average intensity of the absorption peak at the retention time.
From this, it can be determined that the abnormal portion contains slime.

Test Example 4 (Action after slime judgment)
In G paper mill No. H (newspaper paper machine) that has not been sterilized (slime control), spots were frequently generated on newsprints. .
As a result, absorption peaks corresponding to guanine and adenine were observed in the charts of the normal part and the abnormal part, but the absorption peak of the abnormal part was the absorption peak at the retention time corresponding to guanine and adenine in the analysis of the normal part. The average intensity was 5 times. From this, it was determined that the spots on the abnormal part contained slime.

  Therefore, when the operation of the newsprint paper machine was stopped and the inside of the machine was checked, it was found that a large amount of deposits were present on the papermaking tool and that they were mainly slime. From this, it was determined that the slime-based deposit had fallen from the papermaking tool and was incorporated into the paper during the papermaking process, resulting in spots.

Thereafter, the adhering material on the papermaking tool was washed, and the operation of the newspaper papermaking machine was resumed while performing slime control treatment. As a slime control treatment, 2-bromo-2-nitro-1,3diacetoxypropane was added three times at a concentration of 40 ppm for 20 minutes a day.
As a result, spots were not generated and no deposits were observed on the papermaking tool.
That is, according to the identification method for paper product deposits of the present invention, it is possible to quickly and accurately determine whether or not the spot of the paper product generated in the paper mill is derived from slime. it can.

It is a chart figure of the HPLC analysis in the abnormal part of a paper product (Test Example 1). It is a chart figure of the HPLC analysis in the normal part of a paper product (Test Example 1). It is a chart figure of the HPLC analysis using each reagent of cytosine, uracil, guanine, adenine, and thymine. It is a chart figure of the HPLC analysis in the abnormal part of a medium quality paper (test example 2). It is a chart figure of the HPLC analysis in the normal part of a medium quality paper (Test example 2). It is a chart figure of the HPLC analysis in the abnormal part of middle and lower grade paper (Test Example 3). It is a chart figure of the HPLC analysis in the normal part of middle and lower grade paper (Test Example 3).

Claims (1)

Treat the deposits of the paper product in the paper making process with acid, and similarly treat the peripheral part of the deposits with acid to obtain a treatment solution and a control treatment solution, respectively.
The obtained treatment liquid and the control treatment liquid were subjected to high performance liquid chromatography (HPLC) analysis with a measurement wavelength of 250 to 280 nm,
In contrast to the HPLC analysis results obtained, the following two criteria:
(1) In the HPLC analysis of the treatment liquid, a pair of absorption peaks of purine bases guanine and adenine are present at the same intensity around a wavelength of 260 nm.
(2) The intensity of (1) is at least twice the average intensity of the absorption peak at the retention time corresponding to guanine and adenine in the HPLC analysis of the control treatment solution.
When satisfying, it is determined that the deposit contains slime,
A paper product deposit identification method characterized in that, when the criterion (1) is not satisfied, it is determined that the deposit does not contain slime .

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