JPH0774803B2 - Method of measuring ground pulp content in stock - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a method for measuring the ground pulp content rate in stock. Stone ground wood pulp includes stone ground wood pulp (hereinafter referred to as SGW) that is made from logs, similarly pressured stone ground wood pulp (hereinafter referred to as PGW) that is made from logs as raw material and is pulped under pressure, Pulp manufactured by a method in which the raw material is wood chips and it is pulped using a stone grinder (hereinafter referred to as FGP), the temperature of the hot water shower pouring into the grinder at the time of manufacturing with the SGW improved pulp is relatively high. There are various types of stone groundwood pulp, such as pulp that is then pulped (hereinafter referred to as TGW), but these are collectively referred to as GP below. The present invention provides a paper product such as a newspaper, a wrapping paper, or the like containing any one or more of GPs, or a GP content in a stock material such as a raw material of an intermediate pulp collected in a pulping process in a factory, quickly and The present invention relates to a method for easily measuring.

[Prior art]

Conventionally, as the method for measuring the GP content rate in the paper stock, the counting method adopted by TAPPI (Paper and Pulp Technology Association: USA) standard method T401 and the like is used. This counting method is performed by the method described below. The microscope is focused on the fiber surface of the preparation prepared by dyeing with an appropriate dyeing solution, and the stage is finely moved to center it at a point 2 to 3 mm from the edge of the cover glass. The stage is designed so that the observation area can move laterally in a straight line.
Gradually move the stage. Counting is then performed as the various fibers pass under the center of the crosshair. At this time, when one pulp fiber passes through the center of the cross hair more than once,
Count each time. However, if a major portion of pulp fiber passes under the center for some time, it is counted as one. The pulp fiber bundles that are often present in the GP carefully count the fibers in the bundle as it passes under the center, ignoring extremely fine fiber fragments. However, slightly larger fragments were counted as fractions, and fiber fragments of the same type were
When three are accepted, add them by arithmetic so that they are combined into an integer. After counting all the fibers on a straight line in this way, the stage is moved to a new line of 5 mm in the vertical direction, and pulp fibers are counted in the same manner. In this way all the pulp fibers in the four separating lines across the slide every 5 mm are counted. Usually, the total number of pulp fibers is as high as 200 to 300. Next, the total number of each type of pulp fiber is multiplied by each weight coefficient (for example, GP is 1.3) to obtain the corresponding pulp fiber weight, and the percentage to the weight of the total pulp fiber component is calculated. The GP content in the paper stock can be calculated by the above method.

[Problems to be Solved by the Invention]

However, the conventional technique, namely the TAPPI reference method T401
In the counting method using, for example, thermomechanical pulp (pulp obtained by defibrating wood chips by a refiner under pressure, hereinafter referred to as TMP) or chemi-thermo-mechanical pulp (in the TMP, the wood chips are impregnated with a chemical solution and its state It is impossible to determine the content rate of GP alone in the stock containing pulp obtained by pressure refining in the following (hereinafter referred to as CTMP), and it is impossible to determine the content rate of GP alone. Even if it can be done, it is important to control the GP content in the stock for the purpose of yield control of pulp raw materials including GP and quality design of GP-containing paper, and a rapid and simple measurement method is desired. Was there.

[Means for Solving the Problems]

In order to solve the above problems, the present inventor has analyzed the distribution of fiber lengths for various paper materials, and the GP weighted fiber length distribution is waste paper deinked pulp (hereinafter referred to as DIP), TMP,
CTMP, softwood kraft pulp (hereinafter referred to as NKP), hardwood kraft pulp (hereinafter referred to as LKP), refiner groundwood pulp (hereinafter referred to as RGP), and other pulps other than GP (herein referred to as non-GP) ), It was found to be significantly different. And, for each stock that mixed various GP and various non-GP at different ratios, a large number (i = 1,2,
3, ....) are classified according to the fiber length, and the weighted number Mi of the fiber content (= average fiber length li × fiber number ni in each classification) is measured for each classification ΔLi, and each Fiber length of the section Weighted number Mi
Percentage of the total number of fiber length weights for all categories ΣMi
When Ni% (= Mi / ΣMi × 100%) is calculated and a distribution table is drawn,
As in Figure 2 of the example, all stocks have fiber length = 0.
There is a fiber length section showing a maximum value of Ni%, Nmax%, in the range of 2 mm to 0.4 mm. Furthermore, when a graph was drawn with Nmax% on the horizontal axis and the GP content on the vertical axis, it was also found that there is a linear correlation between the two, as shown in FIG. Therefore, even for paper stocks with unknown GP content, with GP and β as constants, the GP content GPwt% = α × Nmax% −β
The estimation formula of is established. However, in the above formula, Nmax% can be obtained by measuring and analyzing a sample of the stock material to be measured with an analyzer such as a fiber length analyzer of Kayani FS-200, but the constants of α and β are as described above. It cannot be directly obtained from measurement and analysis results. However, two stocks with different GP content% GPwt% and known values were measured and analyzed, and each GP was analyzed.
By substituting the contents of GPwt% and Nmax% into the above equation, the constants α and β can be determined from the two simultaneous equations. Further, by increasing the number of stocks to be measured and analyzed and determining the constants α and β by the method of least squares, the constants α and β can be determined with higher accuracy. Thus, if the constants α and β are determined, a stock consisting of an unknown type of GP and an unknown type of non-GP, and the stock of which the content rate of the GP is unknown, the Nmax% The value is calculated, and the value of Nmax% is GPwt% = α × Nmax% −β
Substituting into the formula, the content rate of GP can be obtained. Incidentally, the fiber length analyzer of Kayani FS-200 is used as a machine to mechanically divide the fiber length into a predetermined number, calculate the weighted number of fiber lengths in each division, and analyze the result. It is widely used and is best used.

【The invention's effect】

In the formula GPwt% = α × Nmax% −β, the constants α and β are determined in advance from known stocks, and then a paper or pulp sample with an unknown GP content is determined by a fiber length analyzer. Analyze and obtain the value of Nmax%, and use that value as GPwt% = α × Nm
By substituting into the formula of ax% -β, the GP content can be immediately obtained, which is extremely simple and can achieve the intended purpose in a short time compared with the conventional method.

【Example】

Six stocks a to f with different GP and non-GP contents (GP
wt%: non-GPwt% = 0: 100,20: 80,40: 60) was prepared. For details, each weight% of SGP: TPM: DIP: NKP is equivalent to the stock a = 0:60:
20:20, paper charge b = 20: 40: 20: 20, paper charge c = 40: 20: 20: 20, paper charge d = 0: 20: 60: 20, paper charge e = 20: 20: 40: 20, Paper fee f = 40: 20: 2
There are a total of 6 at 0:20. Then, put each of the above stocks into a mixer (drop the blades in advance) and thoroughly disintegrate, adjust the concentration to about 0.03 wt%, and take about 50 ml of each in a beaker, and water of the above six stocks. A sample of the suspension was made. Next, the pulp fiber length distribution of each stock was measured using a fiber length measuring device (in this example, the fiber length analyzer of Kayani FS-200 shown in FIG. 3). That is, the tip of each of the stirrer 1, the suction thin tube 7 and the drainage thin tube 8 of the fiber length measuring instrument is inserted into the sample S of the concentration-adjusted pulp water suspension in the beaker 2 and the measuring instrument Turn on the switch (not shown). During the measurement, the pulp water suspension S is stirred by the stirrer 1 and circulated through the thin tubes 7 and 8 so that the concentration of the suspension S is always kept uniform. The suspension S sucked up by the thin tube 7 flows down through the capillary 3 having an inner diameter of 0.4 mm, and the pulp fiber F suspended in the suspension P in a scattered state is irradiated with the light from the laser emitting section 5. At the same time, the light is received by the light detection unit 6, and a signal corresponding to the length of the pulp fiber F is emitted from the light detection unit 6. This signal is further processed by a microprocessor (not shown), and the preset fiber length segment Δ
Pulp fiber length weighted number Mi for each Li (i = 1,2,3, ... 144)
The percentage Ni% with respect to the sum ΣMi of all categories is calculated.
FIG. 2 is a distribution diagram of Ni%. However, P = 1 is sample a
And d, P = 2 represent samples b and e, P = 3 samples c and f. From the above measurement results, the fiber length for each of the 6 stocks af
The maximum value Nmax% of Ni% in the range of 0.2 to 0.4 mm was read, and the graph of FIG. 1 was created by setting the Nmax% and the known GP content as two variables. From the graph results, Nmax% and GP content
Since there is a nearly linear correlation with GPwt%,
GPwt% = α × Nmax% − β GP content rate estimation formula with ax% and known GP content as variables, and α = 7.
6, β = 85 was determined.

[Brief description of drawings]

FIG. 1 is a graph showing the correlation between GPwt% and Nmax% in the example.

[Fig. 2] Distribution chart of Ni% in Examples

[Fig. 3] Schematic diagram showing the structure of Kayani Fs-200 fiber length analyzer

[Explanation of symbols]

 1 ... Stirrer 5 ... Laser emission part 6 ... Light detection part 7 ... Suction thin tube 8 ... Drainage tube F ... Pulp fiber S ... Pulp water suspension

Claims (1)

[Claims] 1. A method for measuring the content of ground pulp in a water-containing state in a stock containing ground pulp, comprising: a. Ground pulp content, with α and β as constants
Formulate an estimation formula of GPwt% = α × Nmax% −β. B. The length of the pipe fiber of the sample of the stock material to be measured is measured by using a pulp fiber length analyzer for two or more samples whose ground pulp contents are different from each other and are known,
The measurement results are classified according to the fiber length, the fiber length weighted number Mi for each fiber length category and the fiber length weighted number ΣMi of all category totals are calculated, and the percentage of Mi to ΣMi is calculated.
Ni% is displayed for each fiber length category, and c. Maximum value of Ni% in the fiber length range of 0.2 mm to 0.4 mm
Read Nmax%, determine the constants α and β from Nmax% and the known ground pulp content, and d. Subsequently, the stock material to be measured whose content rate of ground pulp is unknown was analyzed using the above pulp fiber length analyzer in the same manner as the above sample, and e. From the analysis result, read the maximum value Nmax% of Ni% in the fiber length range of 0.2 mm to 0.4 mm, and substitute the value of Nmax% into the above estimation formula, and the ground pulp content rate GPwt of the measured stock GPwt A method for measuring the ground pulp content, which comprises calculating%.