JPS588195A - Mechanical pulp manufacturing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION In particular, the present invention relates to a method for producing mechanical pulp comprising energy-saving sofaning of compressed deformed chips or compressed deformed wood blocks.

In recent years, RMP (Re7ainer groundwood pulp), (RMP (
Mechanical pulps such as chemically pretreated 7-ainer groundwood pulp), TMP (thermomechanical pulp) and CTMP (chemically pretreated thermomechanical pulp) are used mainly for newsprint, medium-quality paper, low-grade printing paper, tissue, and sanitary products. It occupies an important position as a raw material pulp, and there is a strong demand for its use from the standpoint of resource conservation and pollution prevention. From the viewpoint of effective use or resource saving of wood resources in the pulp and paper industry, mechanical pulping is superior to chemical pulping, and will be an extremely important pulping method in the future. However, when compared with chemical pulping, one of the drawbacks of mechanical pulping is that it consumes a lot of electricity. The power consumption in the chemical pulping method is 200 to 400 KW hours/ton, while in the mechanical pulping method it is 1500 to 3000 KW hours/ton.

Therefore, it cannot be said that this is a preferable pulping method from the viewpoint of energy saving. In particular, the power consumption has been attracting attention recently due to its high quality (RMP method has a power consumption of 1,500 to 1,800 KW/ton, while TMP method has a power consumption of 2,000 to 2,500 KW/ton). Time/
Due to the rise in energy costs, especially electricity, caused by the recent oil crisis, there is an urgent need to save energy in mechanical pulping methods, and various methods have been proposed. They can be broadly classified as follows.

(1) Method of refining by adding cMe (carboxymethyl cellulose How to sleep on the sofa - Japanese Patent Publication No. 5S
-3o4si No. 4, 30425 (11υ Sofa inning using cone discs)
JP-A-55-128090, (1v) Method for stabilizing refiner load by equalizing chip supply using ribbon screw - JP-A-55-128090
No. 4-113570 M Coarse crushing and compressive shearing treatment of chips (processing by plex screw or press master) Method for refining chips - International Mechanical Pulp Competition (Inter
national mechanical pulpin
g Conference) preprint (prep
rint) pp. 247-255 (1979), etc. However, with the exception of (11) above, no significant reduction in power consumption while maintaining quality has yet been achieved. .

The present invention has been made in view of the above-mentioned current situation, and its purpose is to provide mechanical pulp that reduces power consumption during mechanical pulp production and is also excellent in quality. The present inventors investigated the above-mentioned known methods from various angles, and in particular, as a result of a detailed study of the above-mentioned (V) method of sofaning coarsely crushed chips and compression-sheared chips, we found that Multi-stage processing of compressed and deformed wood blocks in two or more stages In the sofa lining process, the energy distribution in each stage is optimized, so that the power consumption of the first stage is lower than the power consumption of the second and subsequent stages. By making the size smaller, the total power consumption can be significantly reduced even when considering the power consumption in compressed deformed chips or compressed deformed wood block assemblies, and the pulp quality is also the same or higher than that of conventional methods. I learned that.

That is, in the multi-stage refining process i of compression-deformed chips or wood blocks, the present inventors aim to keep the power consumption of the first stage refining to 5 to 15% of the total sofaning power consumption. In addition, we confirmed that the total power consumption can be reduced by about 20% compared to mechanical pulp of the same quality (same freeness) obtained by multi-stage processing of chips that have not undergone any mechanical deformation using the conventional method. The invention has been completed.

To summarize the present invention, in the production of paper-formable pulp by multi-stage sofaning of compressed deformed chips or compressed deformed wood blocks in two or more stages, the power consumption of the first stage of sofaning is reduced to the total refining power consumption. A method for producing mechanical pulp, characterized in that the amount of mechanical pulp is 5 to 15%.

That is, the present invention is characterized by distributing the power during the sofaning process for the first stage and the second and subsequent stages as shown in the following formula.

1200≦x+y≦2500 (Canadian standard freeness c
sF100mA! (based on the standard) 0.05□≦0.15 x + y In the formula, show.

The compressed deformed chips or compressed deformed wood blocks used in the present invention can be obtained by processing chips or wood blocks with a screw feeder type press, roller press, hammer mill, etc. and applying mechanical deformation.

The power consumption is about 10-30 KW hours per ton of wood. The wood used in the present invention may be either softwood or hardwood (as long as the moisture content of the wood during mechanical deformation treatment is maintained above the fiber saturation point (approximately 20%). Things that should not be done ・It is obvious that the temperature is ℃°・.When mechanically deforming chips or wood blocks △, room temperature is usually sufficient, but if the pressing time is 1 second or less, It is necessary to bring the temperature to around 100'C by steam etc.The pressing pressure is about 50[1 to 5000kl/crrr', and the pressing time is about a few seconds to several minutes.

The chips or wood blocks may be impregnated with sulfite water or sulfite solution before mechanical deformation.
You can press sulfite water or sulfite into the refiner during the sofaning process.

In the conventional multi-stage sofa sleeping process (usually two stages, one or six stages), the electricity consumption of the first stage,
In other words, the energy for defibration is 600 to 1100
Approximately KW hours/ton is required. However, in the method of the invention, the chips or wood blocks are subjected to mechanical deformation, and in the hammer milling of the chips, the chips are broom-shaped (
broom), and when the wood block is pressed, it becomes buckled and the wood is in a semi-fibrillated state, so the power consumption in the first stage is 60 to 575 KWi@/ )/ is sufficient, and [
This value is the total refining power consumption (1200 ~
2500 xw h/ton)], it is nevertheless possible to defibrate wood to the same level as conventional methods. Therefore, from the second stage onwards, refining can be carried out under exactly the same conditions as in the conventional method, and pulp of the same or higher quality can be obtained. The total power consumption can be reduced by about 20% compared to mechanical pulp of the same freeness obtained by refining blocks in multiple stages.

In addition, the degree of sofaing that can be made into paper is RMP.
Te is 50~20 o+alasF, ORMP
50~40 omlcsF, 50~40 for TMP
200m1C3F, CTMP 50-400m
It is about JCiSF and can be processed up to the above-mentioned freeness by multi-stage processing (usually 2-stage or 5-stage).

W, C, Frazier and G, J,
Williams (Preprint A) at the January 1981 annual conference sponsored by the Canadian Press Association (CPPA).
105-A 1 1 1, they announced that they were attempting to save energy in mechanical loop manufacturing by pressing wood in the direction of the fiber axis prior to sofaning, but their method and effects are as follows. This is different from the present invention in this respect.In other words, because they performed the 7-ining method in the same manner as the conventional method, the energy consumption to achieve the same freeness was rather large, and it was not possible to save energy. It is a backward form.

Therefore, when sofalining pressed wood, for example, one of the usual pulp-freeness methods (
10omlcsir) higher freeness (200
This method attempts to save energy by stopping refining at rnlC8F), and is fundamentally different from the method of optimizing energy distribution of the present invention.

The present invention will be explained below with reference to Examples and Comparative Examples.
The present invention is not limited to these in any way.

In addition, Fig. 1 of the attached drawings shows the power consumption (KW hour/ton) for difference example 1 (marked with ○) and comparative example 1 (marked with *).
(horizontal axis) and Canadian standard freeness cstr (mg) (vertical axis). FIG. 2 is a graph showing the same relationship between power consumption and C8F in Example 2 (marked with O) and Comparative Example 2 (marked with *).

Example I A 150t press was used as the TMP method press apparatus. The sofaning device uses a 12-inch pressurized refiner (motor 45KW, rotation speed 3.00Orpm) for the first stage, and
A 12-inch normal pressure refiner (motor 33 KW, rotation speed 3.00 Orpm) was used for the third and third stages. Note that these refining devices were also used in the following examples.

The sample tree species is pine radiata.

In the press stage, a 6 crn x 3 sub-2 crn thick wood block is 1s o o *y7 cn? in the wood fiber axis direction.
Pressure was applied for 10 seconds at room temperature. The power consumption of this press is 20 KW hours.

In the sofa seating stage (see Figure 1), the power consumption of the first stage is (A) 16 OKW hours (B)
200 KW Hour Clock Ton, Canadian Standard Freeness (CS
F) The power consumption required to reach 10.0 rnl is (A) 2050 KW and 215 KW (B)
While there is a 0-KW hour clock ton, in the case of the conventional method (normal chip) (C), there is a 2 Z D OKW hour clock ton. The total power consumption of the press stage is (A)
is 2070 KW hour clock tons (B) is 2170 KW hour clock tons, energy saving rate up to 1 (A) is 23%, (
B) will be 20%. In addition, in the conventional method (normal chip), if the power consumption of the first stage is reduced and the subsequent refining is performed under the same conditions, as shown in (D), C3
The pulp quality is as shown in Table 1, compared to the conventional method.

The same is true. - Implementation Plan 2 A hammer mill was used as the TMP press device. Sambour is fir chips. Process the chips with a hammer mill,
Those that passed the 11m diameter screen were accepted and sent to the next TMP stage. Power consumption in the hammer mill was 25 KW hours/ton.

In the sofaning stage, as shown in Figure 2, the power consumption of the first stage is 200 KW hourly tons, and the power consumption to reach 100 ml of C'SF in the third stage processing is 202 KW.
There were tons of 5KW clocks. The ordinary law is 276 S K
There are tons of W clocks. Therefore, the total power consumption of the hammer mill is 2050 KW, which is 26%.
energy saving rate. The pulp quality is equivalent to that of the conventional method as shown in Table 1.

Example 3 A 150t press was used as the TMP method press apparatus. In the press stage, a block of radiata pine with a size of 6 crn x 3 crn and a thickness of 2 m was compressed in the axial and transverse directions of the wood fibers, each weighing 7 s o kg/
ctr? , 10 seconds each at room temperature. The power consumption required for both presses is 20 KW/hour. With 7 lining stages, the power consumption of the 1st stage is 230 KW/hour, and with 6 stage processing, C8F 1
The power consumption to reach 00ml was 2300KW tons.

The total power consumption including the press stage is 232°KW/hour, which is an energy saving rate of 14% when compared with the conventional method, which is 2,700KW/hour.

The pulp quality is the same as shown in Table 1.

Example J RMP method Using a 150t press, a block of radiata pine with a size of 6 cm x 3 crn and a thickness of 2 m was cut by 75 mm in the wood fiber axis direction.
Pressing was performed at room temperature for 10 seconds at a pressure of ok117cni'. This power consumption is 10 KW hours/ton.

In the refining stage, the power consumption of the first stage is 22 O
The power consumption to reach C3F100rnl with 3-stage processing is 1650 KW tons, while in the normal method it is 2050 KW tons.

The total power consumption including the press stage is 1660 KW/ton, which is an energy saving rate of 19% when compared with the conventional method.

As shown in Table 1, the pulp quality is the average value except for the higher tension.

Example 5 A 150t press was used for the 0TMP method press, and a 6 cm x 5 side, 2 crn thick Loproli pine block was pressed in the axial direction of the wood fibers at 75o*g/1w? Pressing was carried out for 15 seconds at room temperature. The power consumption at this time is 15 KW hours/ton.

In the refining stage, during the first stage sofaning, Na,
SO3 aqueous solution (absolutely dry wood weight as Na2SO3 amount 7
% addition) between the refiner plates.
Therefore, it was added. The power consumption of the first stage is 245 KW hours/ton, and the power consumption required to reach C8F I Q oml in the three stage process is 1900 KW hours/ton. Therefore, the total power consumption including the press stage is:
1915KW hours/ton, csv 1o o by normal method
The power consumption required to reach mHc is 2450 KW
hour/ton, resulting in an energy saving rate of 22%. The quality of the paloop is as in Spring 1, with a slight increase in tightness and specific tear strength, and the same tear length.

Example 6 6 m x s cm, thickness 2 using CTMP method 150t press
crnρ eucalyptus block to wood fiber shaft method 7.5
It was pressed for 15 seconds at room temperature with a pressure of 0 ky/i. This press stage consumed 15 KW hours/ton of electricity.

In the refining stage, an aqueous solution of Na and SO3 (addition of 7% by weight of absolute dry wood as the amount of Na1SOB) was added by pressing between 7 aina plates in the first sofaning stage. 1st stage ℃ power consumption is 1.50
OKW time/ton, C8F 100i with 6-stage processing
The power consumption required to reach 1 was 2100 KW hours/ton. Therefore, the power consumption including the press stage is 2115 KW hours/ton. On the other hand, in the normal method, the energy consumption is 270 OKW hours/t/t, resulting in an energy saving rate of 22%.

As shown in Table 1, an improvement in pulp quality was observed.

As is clear from Table 1 summarizing the results of the Examples and Comparative Examples described above, according to the present invention, an energy saving rate of around 20% can be achieved. In the case of goods, the influence can be said to be significant. Moreover, it must be said that it is unexpected that this is possible with a simple operation as in the present invention, and that the quality of the obtained pulp does not deteriorate.

Therefore, the effects of the present invention can be said to be particularly remarkable.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between power consumption and Canadian standard freeness in Example 1 and Comparative Example 1. No. ・
FIG. 2 is a graph similarly showing the relationship between power consumption and Canadian standard freeness in Example 2 and Comparative Example 2. Patent applicant: Oji Paper Co., Ltd. Agent: Hiroshi Moto Agent: Akiki Inoue ＼ Trouble

Claims (1)

[Claims] 1. Paper making by multi-stage sofaning of two or more stages of compressed deformed chips or compressed deformed wood blocks - In possible pulp production, the power consumption of 7 finning of the first stage is calculated as the total sofaning power consumption. A method for producing mechanical pulp, characterized in that the pulp is reduced to 5 to 15%. 2- The total power consumption of refining is 1200~2
500 KW-hr/ton (Canadian standard 7' Leeney, C
F3F 100 m 175 $) The method for producing mechanical pulp according to claim 1. 3. First stage glue//, power consumption is 60~
375 KWh/t/t/a method for making mechanical pulp according to claim 1. 4. Mechanical pulp manufacturing methods include RMP, ORMP,
TMP. Any of the CTMP methods, Claims 1-
The method for producing mechanical pulp according to any of item 6.