JP6744668B2 - Dry disaggregation/defibration machine - Google Patents

Description

The present invention relates to a dry-type disaggregation/defibration machine for pre-defibrating pulp and producing a raw material to be used for producing cellulose nanofibers.

Since cellulose nanofibers are excellent in strength, elasticity, thermal stability, etc., they are expected to be used in various fields such as plastics, cosmetics, foods and paints.

Cellulose nanofibers can be produced by mechanically defibrating pulp. Conventionally, it requires enormous time and electric power to manufacture because cellulose fibers are miniaturized by repeatedly performing defibration treatment using a disperser having a strong shearing force such as a high-pressure homogenizer. Patent Document 1 describes that the number of times of fine defibration can be reduced by performing preliminary defibration before fine defibration, and uses a conical refiner as the preliminary defibration. However, since the conical refiner is a wet defibrating machine, there is a problem that it is necessary to add water or the like to pulp to form a slurry or suspension.

In addition, a conventional wet defibrator such as a conical refiner or a dry defibrator such as a ball mill gives a mechanical shearing force to cellulosic fibers to defibrate (beat) it, thereby causing damage to the cellulosic fibers. Become. Therefore, when preliminary defibration is performed using a conventional defibration machine, there is a problem in that it is difficult to produce high-quality cellulose nanofibers having a high aspect ratio and high crystallinity.

JP, 2008-48235, A

The present invention provides a dry defibration/defibration machine for pre-defibrating dry pulp as it is to produce a raw material to be used for the production of cellulose nanofibers. More specifically, the present invention provides a dry defibration/defibration machine for producing a raw material for producing high-quality cellulose nanofibers.

In the present specification, beating refers to defibration by applying mechanical shearing force to fibers, and disaggregation refers to defibration of dry pulp in a state where it has little influence on the structural properties of the fibers. Dry pulp refers to pulp having a moisture content of about 0.01% to about 35%.

The present invention for solving the above problems is as follows.

A dry defibration/defibration machine for producing raw materials to be used for producing cellulose nanofibers,
A supply port for supplying raw materials,
A discharge port for discharging defibrated material,
A defibration chamber located between the supply port and the discharge port,
A screen having a plurality of through holes is provided between the discharge port and the defibration chamber,
The defibration chamber is provided with a rotating part inside,
The rotating part includes a rotating shaft and a plurality of plate-shaped fixed blades fixed to the rotating shaft at a predetermined interval in the axial direction,
The fixed blade includes a blade portion protruding in a direction away from the rotating shaft,
One or more protrusions are provided on the inner surface of the defibration chamber,
The protrusion has a recess through which the blade passes when the rotating part rotates.

A dry defibration/defibration machine for producing raw materials to be used for producing cellulose nanofibers,
A supply port for supplying raw materials,
A discharge port for discharging defibrated material,
A defibration chamber located between the supply port and the discharge port,
A screen having a plurality of through holes is provided between the discharge port and the defibration chamber,
The defibration chamber is provided with a rotating part inside,
The rotating unit includes a rotating shaft, a plurality of rotating plates fixed to the rotating shaft at predetermined intervals in the axial direction, a planetary shaft connecting adjacent rotating plates, and a rotatably rotatable planetary shaft. It consists of a planet blade to be placed,
The inner surface of the defibration chamber is provided with one or more protrusions,
By rotating the rotating shaft, the tip edge of the planetary blade is directed toward the inner surface of the defibration chamber by centrifugal force,
There is a gap between the tip edge of the planet blade and the tip edge of the protrusion when the tip edge of the planet blade is directed toward the inner surface of the defibration chamber.

A defibrated material containing cellulose fibers having a crystallinity of 60% or more and less than 100% after defibration/defibration is produced from dry pulp.

The dry disaggregation/defibration machine of the present invention can perform preliminary defibration while the pulp or the like is dried.

Since the dry defibration/defibration machine of the present invention can defibrate (defibration) in a state in which the influence on the structural properties of the fiber is small, by using the raw material produced by the dry defibration/defibration machine of the present invention, It is possible to produce a good cellulose nanofiber.

It is a schematic diagram showing an example of the dry disaggregation/defibration machine according to claim 1 of the present invention. It is the schematic which shows the side surface of the rotating part of FIG. It is the schematic which shows the example of a blade part. It is a schematic diagram which shows an example of the dry disaggregation/defibration machine which concerns on Claim 2 of this invention. FIG. 5 is a schematic view showing a side surface of a rotating unit of FIG. 4 . It is a schematic diagram showing an example of a planetary blade. It is the schematic which shows the example of a screen. 3 is a photograph of the defibrated material of Example 1. 5 is a photograph of the defibrated material of Example 2. 7 is a photograph of the defibrated material of Example 3. 7 is a photograph of the defibrated material of Example 4. 5 is a photograph of Comparative Example 1. 5 is a photograph of a defibrated material of Comparative Example 2. 7 is a photograph of a defibrated material of Comparative Example 3.

Hereinafter, an example of an embodiment of the present invention will be described with reference to the drawings. The present invention is not limited to the examples of the following modes.

First, a dry disaggregation/defibration machine using a fixed blade (claim 1) will be described.

As shown in FIGS. 1 and 2, a dry defibration/defibration machine 1 for producing a raw material to be used for producing cellulose nanofibers of the present invention has a supply port 3 for supplying pulp and the like, and a discharge port 5 for discharging defibrated material, A defibration chamber 7 located between the supply port 3 and the discharge port 5 is provided. A screen 9 having a plurality of through holes 31 is provided between the discharge port 3 and the defibration chamber 7. Inside the disentanglement chamber 7, a rotating portion 11a is provided. The rotating portion 11a includes a rotating shaft 13a and a plurality of plate-shaped fixed blades 17 fixed to the rotating shaft 13a at predetermined intervals 33 in the axial direction. The fixed blade 17 includes a blade portion 15 protruding in a direction away from the rotating shaft 13a. The inner surface 35 of the disentanglement chamber 7 is provided with one or more protrusions 19a. The protruding portion 19a includes a concave portion 21 through which the blade portion 15 of the fixed blade 17 passes when the rotating portion 11a rotates. As an example, the disentanglement chamber 7 is provided with a lid 41 for inspecting the inside of the disentanglement chamber 7 and replacing parts.

The shape of the blade portion 15 of the fixed blade 17 is not particularly limited, but examples thereof include a corrugated shape (FIG. 3, A), a substantially triangular shape (FIG. 3, B), a substantially rectangular shape (FIG. 3, C), and the like. To be The thickness of the fixed blade 17 is not particularly limited, and as an example, the lower limit is 6 mm and the upper limit is 35 mm, preferably the lower limit is 12 mm and the upper limit is 25 mm. The number of blades 15 provided in one fixed blade 17 is not particularly limited, and as an example, the lower limit is 2 and the upper limit is 16, and preferably the lower limit is 4 and the upper limit is 9. The number of fixed blades 17 is not particularly limited. The number of blade portions 15 in each fixed blade 17 may be different, and preferably the same number. The positions of the adjacent blades 15 are not particularly limited, and preferably, the blade tip 47 of the fixed blade 17 and the blade tip 47 of the adjacent fixed blade 17 do not overlap in the direction of the rotation axis 13a ( 1 and 2).

As the fixed blade 17 rotates, the blade portion 15 catches the dried pulp fiber and rotates, and when the blade portion 15 passes through the concave portion 21 of the protruding portion 19a, the pulp fiber is disintegrated and disentangled.

Next, a dry defibration/defibration machine using a planetary blade (claim 2) will be described.

As shown in FIGS. 4 and 5, a dry defibration/defibration machine 1 for producing a raw material to be used for producing the cellulose nanofibers of the present invention has a supply port 3 for supplying pulp and the like, and a discharge port 5 for discharging defibrated material, A defibration chamber 7 located between the supply port 3 and the discharge port 5 is provided. A screen 9 having a plurality of through holes 31 is provided between the discharge port 3 and the defibration chamber 7. Inside the defibration chamber 7, a rotating part 11b is provided. The rotating portion 11b includes a rotating shaft 13b, a plurality of rotating plates 23 fixed to the rotating shaft 13b at predetermined intervals in the axial direction, a planetary shaft 25 connecting adjacent rotating plates 23, and a planetary shaft. 25 and a planetary blade 27 that is rotatably arranged. The inner surface 35 of the defibration chamber 7 is provided with one or more protrusions 19b. Due to the rotation of the rotating shaft 7, the tip edge 29 of the planetary blade 27 is directed toward the defibration chamber inner surface 35 by centrifugal force, and at that time, the tip edge 29 of the planetary blade 27 and the tip edge 37 of the protruding portion 19b. There is a gap 39 between and. As an example, the disentanglement chamber 7 is provided with a lid 41 for inspecting the inside of the disentanglement chamber 7 and replacing parts.

In the rotating unit 11b using the planetary blade 27, the number of the rotating plates 23 is not particularly limited. As an example, the number of planetary shafts 25 is set to a lower limit of 2 and an upper limit of 8, and preferably a lower limit of 3 and an upper limit of 6. There is no particular limitation on the number of planet blades 27 arranged on the planetary shafts 25 that connect the rotating plates 23 adjacent to each other. For example, the lower limit is 1 and the upper limit is 10, and FIG. 5 shows the case of two. The planetary blades 27 may be arranged on all the planetary shafts 25, or the planetary blades 27 may be arranged on a part of the planetary shafts 25. It is preferable that the planetary blades 27 should not be displaced from the positions arranged on the planetary shafts 25 when the rotary plate 23 rotates, and a groove slightly wider than the width of the planetary blades 27 should be formed on the planetary shafts 25 there. For example, the blade 27 may be provided, or protrusions may be provided on both sides of the planetary blade 27.

(Shape and Number of Planetary Blades) The shape of the planetary blades 27 is not particularly limited, but examples thereof include a substantially polygonal shape, a substantially circular shape, a substantially elliptical shape, and preferably a substantially rectangular shape. The tip edge 29 of the planetary blade 27 is, for example, a substantially straight line (FIG. 6, A), an arc shape (FIG. 6, B), an uneven shape (FIG. 6, C), a zigzag shape (FIG. 6, D), or the like. It is preferable that the inner surface 35 of the defibration chamber bulges (see FIG. 1).

The shape of the tip 37 of the protrusion 19b is not particularly limited, and examples thereof include a substantially straight line, an arc shape bulging toward the tip edge 29 of the planetary blade 27, an uneven shape (see FIG. 4 ), and a zigzag shape.

When the rotary plate 23 rotates and the planetary blades 27 pass inside the protrusions 19b, the pulp is disintegrated and disentangled. The gap 39 between the tip edge 29 of the planetary blade 27 and the tip edge 37 of the protruding portion 19b is, for example, a lower limit of 0.5 mm and an upper limit of 12 mm, preferably a lower limit of 1 mm and an upper limit of 5 mm.

Items common to the case of using the fixed blade and the case of using the planetary blade will be described.

The dry disaggregation/defibration machine 1 of the present invention can directly disintegrate/defibrate the dry pulp having a water content of about 0.01% to about 35% into the supply port 3 without slurry or suspension. The means for rotating the rotating portions 11a, 11b is not particularly limited, and a general motor 45 may be used. By the suction means connected to the discharge port 3, the disintegrated/defibrated material of the dried pulp that has passed through the screen 9 is discharged from the discharge port 3. As the suction means for the discharge port 3, a general suction means such as a commercially available suction device may be used.

The peripheral speed of the blade portion 15 or the tip edge 29 of the planetary blade 27 is, for example, a lower limit of 500 m/min and an upper limit of 3000 m/min, preferably a lower limit of 1000 m/min and an upper limit of 2000 m/min. As a suction condition, for example, the passing speed of the disaggregated/defibrated material through the screen 9 is set to a lower limit of 10 m/sec and an upper limit of 40 m/sec, preferably a lower limit of 15 m/sec and an upper limit of 30 m/sec.

The screen 9 has a plurality of through holes 31 (see FIG. 7). The shape of the through hole 31 is not particularly limited and is, for example, a substantially circular shape or a substantially elliptical shape. The diameter of the through hole is not particularly limited, and for example, the lower limit is 0.1 mm and the upper limit is 50 mm, preferably the lower limit is 0.5 mm and the upper limit is 12 mm. The aperture ratio of the screen 9 is not particularly limited, and as an example, the lower limit is 3% and the upper limit is 95%, preferably the lower limit is 10% and the upper limit is 40%. By increasing the diameter of the through holes, the fiber length that has been defibrated and defibrated increases, and by decreasing the diameter, the fiber length that has been defibrated and defibrated decreases. By making the screen 9 detachable, it becomes possible to easily replace the screen 9 with the desired through hole 31.

Pulp disintegration/defibration state by changing the distance between the concave portion 21 of the protrusion 19a and the blade tip 47 of the fixed blade 15 or the distance between the tip edge 37 of the protrusion 19b and the tip edge 29 of the planetary blade 27. Can be changed. For example, the bulk density of the pulp after defibration is increased by narrowing the interval. As an example, the protrusions 19a and 19b may be arranged so as to be able to move in and out from the inner surface 35 of the defibration chamber 7. The means for allowing the projecting portions 19a, 19b to enter and leave is not particularly limited, and for example, a groove 49 is formed in the disentanglement chamber 7, and the groove 49 is provided via a screw means or the like that is normally used. The position at which the protrusions 19a and 19b are provided is not particularly limited, and is attached to the lid 41 as an example.

The dry disaggregation/defibration machine 1 including the fixed blade 17 or the planetary blade 27 can produce a defibrated material containing cellulose fibers having a crystallinity of 60% or more and less than 100% from dry pulp.

Next, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

(Sample material)
As a test material, a softwood sheet (NBKP, manufactured by Alabama River Co.) and additive-free, unbleached toilet paper (manufactured by Oji Paper Co., Ltd., trade name: Napier Nepinepi (registered trademark)) were used. In each case, a piece cut into an appropriate size was subjected to a defibration treatment.

(Dry defibration/defibration machine with fixed blade)
The dry disaggregation/defibration machine equipped with the fixed blades 17 has five fixed blades 17, six fixed blades 15 and a corrugated blade 15. Was used.

(Dry defibration/defibration machine equipped with a planetary blade)
In the dry disaggregation/defibration machine provided with the planetary blade 27, the tip edge 29 of the planetary blade 27 in the rotating part has a zigzag shape. There were used five rotary plates 23, eight planetary shafts 25, and two planetary blades 27 between adjacent rotary plates 23.

(Operating conditions)
In each of the dry defibrating and defibrating machines, the aperture ratio of the screen 9 was 22.7%, the through hole of the screen 9 was circular, and the diameter was 4.5 mm or 1.0 mm. The operating conditions were such that the peripheral speed was 1.85 m/min, and the passing speed of the screen 9 was 18 m/sec.

(Condition of ball mill)
The ball mill used as a comparative example was PM400 manufactured by Retsch. The rotation speed was 100 rpm, and alternate operation was performed for 2 minutes for a rotation time and 2 minutes for a rest time in order to avoid temperature increase. The driving time was the total time of rotation time and rest time.

<<Visual confirmation of bulk density>>
8 to 14 show the results obtained by defibrating the softwood sheet under the conditions shown in Table 1 and the like and then placing it in a 200 ml beaker and visually confirming the bulk density. 8 shows Example 1, FIG. 9 shows Example 2, FIG. 10 shows Example 3, FIG. 11 shows Example 4, FIG. 12 shows Comparative Example 1, FIG. 13 shows Comparative Example 2, and FIG. 14 shows Comparative Example 3. ..

Table 1 shows the defibration conditions of Examples 1 to 4 and Comparative Examples 1 to 3.

As can be seen from FIGS. 8 to 14, the dried softwood sheet cannot be defibrated with a ball mill, but the dry disaggregation/defibration machine of the present invention can defibrate the softwood sheet into fine fibrous shapes while being dried. did it.

<<Measurement of freeness>>
Next, the freeness was measured in order to know the defibrated state by the dry defibration/defibration machine of the present invention. The freeness was measured according to JIS P8121-2 "Canadian Standard Freeness". To measure the freeness, toilet paper was used as a test material.

Table 2 shows the measurement results of the freeness.

In the case of defibrating using the dry defibration/pre-defibration machine of the present invention (Examples 5 to 8), the freeness is smaller than that in the case of defibrating using a ball mill (Comparative Examples 4 and 5), It was found that the disaggregation/defibration effect was high.

<<Measurement of crystallinity>>
The degree of crystallinity after defibration was measured using the dry defibration/defibration machine of the present invention.

(Pretreatment of test material)
As described above, even if the softwood sheet is subjected to a defibration treatment with a ball mill in a dry state as it is, it does not loosen into a fibrous shape. Therefore, in measuring the crystallinity, the sample material was pretreated by the dry disintegration/defibration machine of the present invention. For the pretreatment, a dry defibration/defibration machine having a planetary blade 27 having a zigzag-shaped tip edge 29 was used. Five rotary plates 23, eight planetary shafts 25, two planetary blades 27 are provided between adjacent rotary plates 23, and the through holes of the screen 9 are circular with a diameter of 30 mm. Was cut to have a side of about 100 mm and then supplied to the supply port 3, and the peripheral speed was 1.85 m/min and the passing speed was 18 m/min.

(Method of X-ray diffraction)
The crystallinity was determined by measuring the X-ray diffraction of the sample. The X-ray diffraction was measured by placing an appropriate amount of the sample on an aluminum cap and using an X-ray diffraction measuring device (SmartLab, manufactured by Rigaku Corporation). The crystallinity is calculated (L. Segal, J. J. Greeley, et al, Text. Res. J., 29, 786, 1959) and the method of Kamide et al. (K. Kamide et al, Polymer J., J. 17, 909, 1985), and the diffraction intensity of 2θ=8° to 45° in the X-ray diffraction diagram as a baseline, the diffraction intensity of the 002 plane at 2θ=22.6° and 2θ=18.5°. It was calculated from the diffraction intensity of the amorphous part of
Xc=(I002c-Ia)/I002c×100
Xc = Crystallinity of cellulose (%)
I002c: 2θ = 22.6°, diffraction intensity of 002 plane Ia: 2θ = 18.5°, diffraction intensity of amorphous part

The results of measuring the crystallinity are shown in Table 3.

When the dry disaggregation/defibration machine of the present invention is used, the crystallinity of the cellulose fibers remains high, and the crystallinity of the cellulose fibers produced by the dry disaggregation/defibration machine of the present invention exceeds 85%. Was there.

1 Dry Disaggregation and Disentangler 3 Supply Port 5 Discharge Port 7 Disentanglement Chamber 9 Screen 11a Rotating Part 11b Rotating Part 13a Rotating Shaft 13b Rotating Shaft 15 Blade 17 Fixed Blade 19a Projecting 19b Projecting 21 Recess 23 Rotating Plate 25 Planetary Axis 27 Planetary Blade 29 Tip Edge 31 Through Hole 33 Space 35 Inner Surface 37 Tip Edge 39 Gap 41 Lid 43 Screw Means 45 Motor 47 Blade Tip 49 Groove

Claims (3)

A dry defibration/defibration machine for producing raw materials to be used for producing cellulose nanofibers,
A supply port for supplying raw materials,
A discharge port for discharging defibrated material,
A defibration chamber located between the supply port and the discharge port,
A screen having a plurality of through holes is provided between the discharge port and the defibration chamber,
The defibration chamber is provided with a rotating part inside,
The rotating part includes a rotating shaft and a plurality of plate-shaped fixed blades fixed to the rotating shaft at a predetermined interval in the axial direction,
The fixed blade includes a blade portion protruding in a direction away from the rotating shaft,
One or more protrusions are provided on the inner surface of the defibration chamber,
The dry disaggregation/defibration machine, wherein the protruding portion is provided with a concave portion through which the blade portion passes when the rotating portion rotates.
A dry defibration/defibration machine for producing raw materials to be used for producing cellulose nanofibers,
A supply port for supplying raw materials,
An outlet for discharging defibrated material,
A defibration chamber located between the supply port and the discharge port,
A screen having a plurality of through holes is provided between the discharge port and the defibration chamber,
A rotating part is provided inside the defibration chamber,
The rotating unit includes a rotating shaft, a plurality of rotating plates fixed to the rotating shaft at predetermined intervals in the axial direction, a planetary shaft connecting adjacent rotating plates, and a rotatably arranged planetary shaft. It consists of a planet blade to be installed,
The inner surface of the defibration chamber is provided with one or more protrusions,
By rotating the rotating shaft, the tip edge of the planetary blade is directed toward the inner surface of the defibration chamber by centrifugal force,
Leading edge of the planetary blade have a gap between the leading edge of the leading edge and the projecting portion of the planetary cutter when toward the inner surface direction of該解繊室,
A dry defibration/defibration machine, which is characterized in that a defibrated material containing cellulose fibers having a crystallinity of 60% or more and less than 100% is produced from dry pulp . The dry defibration/defibration machine according to claim 1, wherein a defibrated material containing cellulose fibers having a crystallinity of 60% or more and less than 100% is produced from dry pulp.