JPS58109699A - Grinding of papermaking stock material - 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 The present invention relates to a method for continuously grinding papermaking raw materials,
More specifically, it has a planar grinding section made of fine particles with a particle size of 9, and is made of metal and an organic polymer compound between the grinding section and the drive shaft and between the grinding section and the raw material supply port. A method of grinding papermaking raw materials, which is characterized in that a suspension of papermaking raw materials containing bound fibers is fed under pressure to a disk-type milling machine, and the grinding process is carried out by limiting the circumferential speed of the grinding section. It is something.

The main raw materials for paper production in the paper manufacturing industry are chemical pulps such as kraft pulp and sulfide pulp, ground wood pulp, crushed ice pulp made by pressure, and high-yield pulp. Its importance is increasing.

The manufacturing process of high-yield pulp consists of a coarse crushing process in which mechanical force is applied directly to the plant fibrous material, or mechanical force is applied after heating and/or chemical pretreatment, and It consists of a refining step in which the fibers are further milled.

In any high-yield pulping process, there is always a significant amount of bound fibers present in the crude fiber after the crushing step. If the papermaking raw material contains binding fibers, paper breaks are likely to occur during papermaking, the appearance of the resulting paper is significantly impaired, and there are many problems in terms of printability. 9. Crude fibers are extremely rigid due to their high lignin content, and it is almost impossible to make paper in that state.Therefore, efforts have been made to mechanically transform the crude fibers into a so-called fibrillated state to increase the bonding ability between the fibers. There is a need to. Furthermore, in the crude fiber obtained from hardwood materials, a large amount of vessels exist in an almost unbroken state, but since vessels can cause vessel picks and reduce smoothness of the paper, they must be removed before paper making. It is necessary to destroy it in advance.

The above-mentioned refining process is a process of disintegration of bundled fibers, fibrillation of fibers, and destruction of vessels.Up to this point, we have exclusively used blades 111 and metal wire grates with grooves. They attempted to achieve these objectives by subjecting the crude fibers to seven ainers. However, this method consumes a large amount of glue finishing energy,
Moreover, disintegration of bound fibers, fibrillation of fibers, and destruction of vessels are extremely insufficient. Therefore, in order to save energy and expand the uses of high-yield pulp, there is a strong desire for a method that can efficiently refine crude fibers with less energy.

Examples of known techniques aimed at improving the above-mentioned shortcomings of the Discli 7 Einer include (1)! 17 The blade part of the Einer is made of a sintered porous body of metal particles.
No.) (2) Metallic 7 Einer element consisting of a blade part and a groove part having a filler such as a synthetic resin (Japanese Patent Application Laid-open No. 55-50424
No.) (6) A metal refiner element consisting of grooves S↓ on the blade part and the grinding surface 1 (4I Kaisho No. 55-50425) (
4) A refiner element consisting of a blade part and a groove part is formed with a composition consisting of an abrasive material and an organic polymer compound F.
JP-A No. 55-15728B). Among these,
(1) is a companion intended to improve the efficiency of the sofaning action in the blade part, and (2) to (4) are intended to have an auxiliary or finening action in the groove part, and both are 7
It is thought that the main body of the lining effect is the blade.

On the other hand, the present inventors believe that the above-mentioned problem with the Discri 7 Ainer is due to the fact that there are very few places that apply the abrasive action to the papermaking raw material. (Japanese Patent Application No. 71546/1983) We propose a method based on the principle of 7-inning the papermaking raw material (Japanese Patent Application No. 55-71546). Furthermore, based on the above principle, when papermaking raw materials are subjected to 7-lining, the magnitude of the frictional force acting on the papermaking raw material is We discovered that processing efficiency, especially energy consumption, is an important factor.
He invented a method in which a suspension of papermaking raw materials is supplied under pressure into the gap between the grinding parts, and the magnitude of the frictional force acting on the papermaking raw materials is regulated (%Gai No. 185121/1998). The figure shows an example of a device for carrying out the invention by the present inventors.This friction machine consists of a backing plate 2 and a nut 4.
It has a rotary grindstone 1 attached to a drive shaft 6 and a fixed grindstone 7 which is fastened to a backing plate 8 by a ring-shaped clamp 9 and has a raw material supply port 10. Sections 5 and 11 are provided. The Tomo Paper raw material suspension introduced through the raw material supply port 10 fills a space 16 consisting of a surface 6 between the grinding section 5 and the drive shaft 5 and a surface 12 between the grinding section 11 and the material supply port 10. After passing through, it reaches the space between the grinding parts [1914] and is subjected to a refining action.

However, the method proposed by the present inventors (Japanese Patent Application No. 55-185)
No. 121), when papermaking raw materials are processed using the above-mentioned apparatus, the processing conditions may vary depending on the type of papermaking raw materials, such as the surface 6 between the grinding section and the drive shaft and the surface 6 between the grinding section and the raw material supply port. Face 12
(Hereinafter, such surfaces are referred to as raw material passage surfaces)
Hereinafter, this space will be referred to as the raw material passage section] where the papermaking raw material #I
In some cases, it was difficult to stably supply raw materials.

Therefore, a high supply pressure of 7 tons is required, and when the raw material passage surface and the papermaking raw material are opened, friction occurs between the papermaking raw materials and energy loss occurs, and furthermore, the raw material passage section is completely blocked. Treatment was often impossible. These phenomena become particularly noticeable when the concentration of the papermaking raw material suspension is high, and in the above invention, it is necessary to carry out the treatment at a relatively low concentration.

Therefore, in order to solve the above problems and improve the stable supply of raw materials and the processing concentration, the present inventors investigated the cause of raw materials clogging the raw material passage section. As a result, if the material passing surfaces 6 and 12 are rough surfaces of the grindstone, as in the case of the grinding device shown in FIG. Investigate. The inventors of the present invention have found that reducing friction loss by making the raw material passage surface a surface made of metal or an organic polymer compound helps to solve the above problems. Furthermore, the present inventors solved the above problem by keeping the circumferential speed of the grinding disk sufficiently high to increase the shearing force acting on the papermaking raw material suspension in the raw material passage section and promote the dispersion of the backing paper raw material. A friend who discovered something that could be contributed to. On the other hand, it has become clear that if the circumferential speed of the grinding disk becomes too high, the fluid friction loss (water resistance) in the gap between the grinding parts will increase significantly, and a large amount of energy will be wasted. That is, the present inventors found that it was necessary to set a restriction on the circumferential speed of the grinding disk.

The present invention has been made from the above viewpoints, and the present invention is made by applying bundled fibers to a disc-type attrition machine in which the attrition part is a plane made of fine particles of a specific particle size, and the raw material passing surface is made of metal or/and an organic polymer compound. The purpose of the present invention is to provide a novel method for grinding papermaking raw materials, which is characterized in that a papermaking suspension containing a papermaking suspension is fed under pressure and the grinding process is carried out by limiting the circumferential speed of a grinding disk.

The present invention will be specifically explained below.

First, the raw material passing surface is made of metal or/and an organic polymer compound, but in the case of a disc-type grinder as shown in Figure 1, an organic polymer compound is applied to the raw material passing surface to fill the pores of the grindstone. The first method is filling. 19. As a second method, one liter of organic polymer compound may be attached to a metal thin plate or film on the raw material passage surface. Furthermore, as a third method, an example of which is shown in FIG.
5 and attach the annular object 1 to the backing plate 8 of the fixed grindstone 7.
6, and these objects are made of metal or organic polymer compounds.

Note that six methods such as 2 may be used in combination; for example, an organic polymer compound may be applied to the raw material passing surfaces 30 and 31 in FIG.

The organic polymer compounds used in the above method include thermosetting resins, thermoplastic resins, various rubbers, and mixtures thereof. hardener, pigment.

Other additives can be included. Examples of metals include steel, stainless steel, copper, various steel alloys, aluminum, and various aluminum alloys.

In the first and second methods, suitable materials are selected mainly for their adhesion to the grinding wheel, and in the third method, they are selected mainly for their strength properties.

Another method of making the material passing surface a metal surface is to attach a grindstone grinding section to an existing disc refiner. FIGS. 6 to 5 show an example in which an annular grindstone 21 is attached to the rotating disk 18 and fixed disk 26 of an Aku, Single Disc 7-Einer via a holder 20. The holder 20 is made of steel, and the discs 18 and 26
is made of stainless steel, so the raw material passing surfaces 24 and 32 are metal surfaces. Note that an organic polymer compound can be applied to the raw material passage surface 66.

In all of the methods described above, the raw material passing surface does not require particularly precise machining, so there is no need to strictly define the surface roughness, but as a rough guide, the center line average roughness should be 50μ or less. It is preferable if it is of a certain extent. (9) Although it is desirable that the entire raw material passing surface be made of metal or/and an organic polymer compound, a portion of the raw material passing surface, such as the vicinity of the grinding section, may be a rough surface. Furthermore, 17 and 5 in Figure 2
A stirrer blade is attached to the drive shaft as shown at 28 in FIGS. Although it is not shown in the drawing, if a stirring blade is attached to the material passage surface,
This is advantageous because the dispersion of the papermaking raw material in the raw material passage section is further promoted.

Note that it is desirable that the above-mentioned grooves or stirring blades provided on the raw material passing surfaces exist on both opposing raw material passing surfaces.
It is also possible to use only one side.

Next, in the present invention, there is a limit on the circumferential speed of the grinding section, and first, the lower limit will be explained. In the raw material passage section, the papermaking raw material suspension is subjected to shearing force due to the rotation of the disk, and this action is important for suppressing fiber entanglement, that is, flocculation, and improving the dispersion state of the raw material. Therefore, if the shearing force is small, the dispersion state of the raw material will be poor and this will be a cause of clogging of the raw material passage section. As a result of experiments, it has been found that the dispersion state of papermaking raw materials becomes better when the peripheral speed at the outer periphery of the grinding section is 10 rn-/s'ec or more. It is well known that energy loss due to the viscosity of water increases as the speed increases, but in the present invention, all or most of the surface of the grinding section is composed of fine particles. The effect of energy loss due to water is extremely large because the grinding surface is very thin and the gaps between the grinding parts are considerably closed (usually 0~50μ).Figure 6 shows Kumagai Riki Kogyo ( Experimental results when the grinding unit of the present invention (alundum grindstone with grain size 80) or grooved steel disk plate (N118034N) was installed on the Single Discre 7 Ainer (12 inches) manufactured by Co., Ltd., and only water was treated. In the figure,
The dotted line indicates the case when the grinding section of the present invention is used, and the dotted line indicates the case when a grooved steel disc plate is used. V indicates the relative peripheral speed (''/5ec) of the outer periphery of the grinding section. Comparing the gap between the grinding parts and the same, the grinding part used in the present invention has a larger water load than the grooved disc plate, but by halving the circumferential speed, the water load can be significantly reduced. Therefore, in the present invention, it is necessary to strictly define the upper limit of the circumferential speed of the grinding section, and as a result of experience, when the circumferential speed at the outer circumference of the grinding section exceeds 45n'-/βec, the energy decreases. The amount consumed is extremely high.

The present invention is based on the earlier invention (Japanese Patent Application No. 185121/1989).
Similarly, the grinding part is a flat surface without blades or grooves, but the accuracy of the particles that make up the grinding part is the energy consumption.

Subsequent research by the present inventors has revealed that there is a close relationship between the throughput per unit time and the frictional force acting on the papermaking raw materials. Particle size is J Engineering SR, 6001-197
If the grain size is coarser than No. 56, which has a grain size of 9, the frictional force will not work sufficiently, resulting in a small throughput and a large amount of energy consumption. On the other hand, if the particle size is finer than No. 150, it is undesirable because the raw material is likely to clog the raw material passage, a high supply pressure is required, and the fibers are easily cut, resulting in a decrease in paper strength. In addition, since there is a good correlation between particle size and frictional force as described above, in the present invention, it is unnecessary to specify the frictional force as in the previous invention.

In the present invention, it is desirable that the above-mentioned particles exist over the entire surface of the grinding section, but the particles may not be present in a part of the grinding section, such as the part of the bolt that attaches the grinding wheel to the disk. No problem.

Generally, one of the opposing grinding sections and the other grinding section are composed of particles of the same particle size, but it is also possible for the particles of both grinding sections to have different particle sizes.

It is also possible to form a grinding section by mixing particles of different particle sizes, and it is also possible to divide the grinding section into concentric circles, for example, to make the particle size coarser on the inner periphery.

Types of particles include artificial abrasives such as aluminum oxide, silicon carbide, boron carbide, titanium carbide, tungsten carbide, boron nitride, artificial diamond, and natural abrasives such as garnet, corundum, emery, silica stone, and diamond. However, aluminum oxide and silicon carbide are the most common.

As the binder for the secondary particles, inorganic binders such as vitrified, silicate, and oxychloride, and organic binders such as resinoid, rubber, and shellac can be used. Furthermore, a sintered body of particles of metal, synthetic resin, etc. can also be used as the grinding part.

The grinding portion of the present invention is generally an annular plane perpendicular to the central axis of the disc, but it can also be an inclined annular plane, and it can also be a convex or concave surface.

Regarding the concentration of the papermaking raw material suspension, in the present invention, by improving the raw material passage part and specifying the circumferential speed, it is possible to process even higher concentrations than in the previous invention, generally the solid content concentration is 0.5 to 0.5.
6.0% by weight is desirable. As described above, in the present invention, there are cases where processing is performed at a higher concentration than in the previous invention, so the supply pressure of the papermaking raw material suspension is 0.2 to 10.0 kj'.
A pressure of /,2 (gauge pressure) is required.

The gap between the grinding parts is preferably 0 to 50μ, but if the papermaking raw material contains a significant amount of coarse bundled fibers, a gap of 50 to 500μ may be used as a preliminary treatment.

Disc-type mills for carrying out the present invention include single-disc 7-iner, double-disc refiner, etc.
Wet mills such as disc refiners and colloid mills commonly used in the paper industry can be used, but any other mills can be used as long as they meet the basic idea of the present invention. There are two types of double disc refiners: one has a single rotating disc with fixed discs on both sides, and the other has two six discs that rotate in opposite directions, but considering the circumferential speed, the former is better. It is preferable.

The papermaking raw materials processed according to the present invention include the crushing method,
Waste paper and pulp mills containing crude fibers, refined fibers, and high-yield pulp obtained by high-yield pulping methods such as pressure crushing method, refiner crushing method, thermomechanical method, chemi-mechanical method, and semi-chemical method. The present invention can also be applied to the treatment of chemical pulp or waste paper made of chemical pulp.

As detailed above, it can be said that the method of the present invention improves on the previous invention by the present inventors and makes it possible to stably supply raw materials and improve the processing concentration, and thus has further increased its practical value.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited in any way by the following examples. EBOKI 7 resin (Araldite adhesive) on raw material passing surfaces 6 and 12 of (colloid mill)
After carefully applying the pine wood chips to the regular disk
Crude fiber obtained by processing with Einar under normal pressure (F Suisan 45Q
m, 1 C0S, F. ) is supplied with a solid content concentration of 2.0% by weight through a bonder and subjected to a grinding process. The rotary grindstone 1 and fixed grindstone 7 of the grinder used both have a grain size of 60.
Vitrified grinding wheel (Alundum), the outer diameter of the grinding part is 254WL.

The inner diameter is 192. , -. On the other hand, for comparison purposes, the same crude fibers were treated in the above-mentioned attritor with the raw material passing surfaces 6 and 12 positioned outside the grinding wheel surface.

The treatment conditions in the above treatment, the furnace water level of the pulp after treatment, and the total energy consumption (including idle link loss) are as shown in Table 1.

Table 1 In addition, in any case, the number of bundled fibers in the pulp after treatment is extremely small. Pressure can be lowered, and energy consumption is also reduced.

Example 2 12-inch single disk drive 7 manufactured by Kumagai Riki Kogyo Co., Ltd.
A vitrified grindstone with a grain size of No. 80 (
[Alundum] 21 was attached, and a suspension of the crude fibers with a solid content of 4.2% by weight was supplied by a pump to perform a grinding treatment.

The raw material passage surface 24 of this single disc 7-iner is made of stainless steel, and the outer diameter of the grinding part is 300 mm.

The inner diameter is 204m&. The circumferential speed at the outer periphery of the grinding part was 25.6″/sec, but for comparison, it was 47.1 m.
, /8ec also performs processing. On the other hand, as another comparative experiment, we conducted a first experiment in which the outer diameter of the grinding part was 94mm and the inner diameter of the grinding part was 68mm.
The disk type grinder shown in the figure is equipped with a vitrified grindstone of grain size IAO (
Aranda A) 1 and 7 are installed and raw material passing surfaces 6 and 1 are installed.
2 is a mill in which a suspension of the same crude fibers with a solid content concentration of 2.0% by weight is supplied by a pump to carry out the grinding process using a grinding wheel with a side surface.

In this comparative experiment, an attempt was made to grind at a treatment concentration of 3.0% by weight, but the raw material passage section 15 was blocked by crude fibers, making grinding impossible.

The treatment conditions in the above treatment, the amount of F water and energy consumption of the pulp after treatment are shown in Table 2.

Table 2 shows that in all treatments, only a small amount of bundled fibers were obtained in the bulb. As shown in Table 2, in the present invention, the raw material passing surface is a metal surface, and the stirring blade 28 and the groove 2
9, it was possible to process at a higher concentration than in the previous invention by the present inventor (Comparative Experiment 1). On the other hand, it has also become clear that when the circumferential speed becomes too high, the energy loss due to water increases dramatically, and the total energy consumption increases significantly (Comparison 51iEJ2).

Example 6 The outer diameter of the grinding part of the disk type grinder shown in Fig. 1 is 254mm.

The same internal diameter 154rrLM, particle size No. 60 mill is equipped with a No. 100 vitrified grindstone (Alundum), and the crude fibers are fed through a pump at a solid content concentration of 2.0% by weight to carry out the grinding process. In both cases, the raw material passing surface is the same as in Example 1.
Similar epoxy resin binding.

The treatment conditions in these treatments, the amount of F of the pulp after treatment, the amount of energy consumed, the frictional force acting on the crude fiber, and the Jl
The paper quality of the handmade paper prepared by the S method was 9 in Table 6, and almost no binding fibers were observed in any of the handmade papers.

Table 6 The frictional force in Table 6 is calculated using the formula below.
f is the frictional force (k
1'/(-) # d is the absolute dryness of the crude fiber.The apparent weight is y
//R&], P is the load (-kf island/8θ
a] +Pw is the load ('JE-~ec) when only water is treated under the same conditions as when grinding the crude fibers, o is the solid content concentration of the crude fiber suspension CkVyn, s] * w is the rotating grindstone angular velocity (1/5ea).

r□ is the outer radius (m) of the grinding section, and rl is the inner radius [horse] of the grinding section.

From these experimental results, it has been shown that the finer the particle size of the particles constituting the grinding section, the greater the frictional force that can be obtained, which increases the throughput per unit time. It was found that the total energy consumption was reduced. It has also been observed that the coarser the particle size, the lower the supply pressure, and the less likely the fibers will be cut, resulting in improved paper strength.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an example of a disk-type grinder for carrying out the present invention and previous inventions by the present inventors, and FIG. 2 is a longitudinal sectional view of a ninth disk-type grinder for carrying out the present invention. A longitudinal cross-sectional view showing another example, Fig. 6 is a longitudinal cross-sectional view of an existing single-disc refiner with a grinding wheel installed, and Fig. 4 is a front view of the rotating disk taken along line A-A in Fig. 6. , FIG. 5 is a front view of the fixed disk taken along the line B--B in FIG. 6, and both are schematic diagrams showing only the portions related to the present invention. FIG. 6 is a diagram showing the relationship between the load due to water and the gap between the grinding parts. In Figures 1 to 5, 1. Rotating whetstone 8. Grinding plate 2. True plate 9. Ring-shaped rung 5.
Drive shaft 10... Raw material supply port 4... Nut
11.. Grinding section 5.. Grinding section 12.. Raw material passing section 6.. Raw material passing section 13.. Raw material passing section 7.. Fixed grindstone 14
... Grinding part gap 15... Dish-shaped object 25... Grinding part gap 16... Annular object 24... Raw material passing surface 17... Stirring blade 25... Raw material passing part 18... Rotating disk 2
6. Fixed disk 19.. Drive shaft 27.. Raw material supply port 20.. Holder 28.. Stirring blade 21.. Grindstone 29.. Groove 22.. Grinding section 30.3i, 52, 33-
, raw material passage surface rice 1 figure (O・2 figure 13 figure 2, 4 figure 8 λ'5 figure 16 figure 0 19th Japan Patent Office Commissioner Shima 1) Haruki Tono1, Indication of the case Patent Application No. 203428 of 19832, Name of the invention Method for grinding paper raw materials3, Relationship with the person making the amendment Patent applicant address Tokyo 1-4-5 Marunouchi, Chiyoda-ku, Tokyo Name (2
34) Sanyo Kokusaku Pulp Co., Ltd. President Masayoshi Ninomiya 4, Agent 100 Address 1-4-56 Marunouchi, Chiyoda-ku, Tokyo Column 7 for detailed explanation of the invention subject to the amendment, Statement of contents of the amendment We will correct the following points. (1) On the 7th line of page 3, "Put pressure on the suspension" is corrected to "J by applying pressure on the suspension." (2) On the bottom line of page 6, "Friction machine" I will correct the statement to "grinding machine". (3) On page 9, line 8, the phrase “paper manufacturing suspension” will be corrected to “paper manufacturing raw material suspension.” (4) In the 2nd line of page 12, the phrase "to face" has been corrected to "to face". (5) In the second line from the bottom of page 13, we have corrected the phrase "The accuracy of a particle is" to "The particle size of a particle is." (6) On page 14, line 3, we have amended the phrase "as stipulated in r-1973" to "as stipulated in r (1973)." (7) The words ``Method of the present invention'' and ``Comparative experiments'' in the upper row of Table 3 on page 22 will be deleted. (8) Correct "rwJ" in the denominator of the formula on the 4th line of page 23 to "ω". (9) In the 11th line from the bottom of page 23, "W is rotation" will be corrected to "ω is rotation." (10) In the 10th line from the bottom of page 23, "r, grinding section" will be corrected to "ri, grinding section."

Claims (1)

[Claims] 1. Each of the opposing surfaces of the opposing disks has a band-shaped grinding portion that is continuous in the circumferential direction and has no blades or grooves,
The entire surface or most of the surface of the grinding part is J Engineering EI R6.
001 (a plane consisting of particles corresponding to numbers 66 to 150 specified in 1973), and the plane between one of the opposing grinding parts and the drive shaft, and the center between the other opposing grinding part and the drive shaft. A papermaking raw material suspension containing binding fibers is placed between a milling machine and a raw material supply port, the entire or most of which is made of metal and/or an organic polymer compound.
OkP/C11l! (gauge pressure) and the grinding process is carried out at a relative circumferential speed of 10 to 45° at the outer periphery of both grinding sections. 2. One side facing oppositely A patent claim having radial grooves on either or both of the surface between the grinding section and the drive shaft and the surface between the other opposing grinding section and the raw material supply port set around the center. A method for grinding papermaking raw materials according to item 1. 6 Nine raw material supply ports are provided on the surface between one of the opposing grinding parts and the drive shaft, and around the center of the other opposing grinding part. A method for grinding papermaking raw materials according to claim 1, which has stirring blades on both or one of the surfaces between the two.
The method for grinding the papermaking raw material according to item 1, which is any one of items 1 to 3. 5. The method for grinding papermaking raw materials according to any one of claims 1 to 4, wherein the solid content concentration of the papermaking raw material suspension is 0.5 to 60 mouths by weight. 6. The method of grinding papermaking raw materials according to any one of claims 1 to 5, wherein the gap between the grinding parts is 0 to 300μ.