WO2008010325A1

WO2008010325A1 - Process for producing pellet

Info

Publication number: WO2008010325A1
Application number: PCT/JP2007/052739
Authority: WO
Inventors: Mitsuhiro Sato; Naoki Eto
Original assignee: Kankyokeieisogokenkyusho Co., Inc.
Priority date: 2006-07-18
Filing date: 2007-02-15
Publication date: 2008-01-24
Also published as: KR101273171B1; KR20090047338A; JP2008023724A; JP4806305B2

Abstract

A process for producing pellets that although maintaining a given configuration, are disintegrated under low pressure. The process for producing pellets includes the kneading step of making a hydrous mixture, the pelletizing step of forming the mixture into multiple pellets of given configuration and the drying step of reducing the water content of the pellets. In the pelletizing step, an alcohol capable of removing the frictional heat at the pelletizing of the mixture as vaporization heat is injected. In the drying step, the travel distance of belt conveyor (59) from entrance opening (56) to discharge opening (57) of unit (58) is in the range of 1 to 20 m, and the traveling speed of the belt conveyor (59) is in the range of 0.02 to 0.1 m/s. The internal temperature of the unit (58) is maintained at 45° to 50°C by means of heater (60).

Description

Specification

Pellet manufacturing method

Technical field

[0001] The present invention relates to a pellet manufacturing method for producing pellets.

Background art

[0002] Pulverized paper and pellets made of starch and plastic resin are put into an extruder, and the pellet and plastic resin are mixed with heating inside the extruder to produce a high-temperature melt. There is a foam manufacturing method in which a melt is foamed at a predetermined magnification by vaporization of water injected into a machine (see Patent Document 1). The pellets used in this manufacturing method are made by the following method. The paper pulverized product and starch are stirred for about 60 minutes with a ribbon mixer, then transferred to a kneader, added with water, kneaded for about 5 minutes with a kneader to form a mixture, and the mixture is granulated with a wet granulator. To make multiple pellets. Pellets are stored in a dryer, dried in a dryer at 50 ° C for 12 hours, mixed vigorously, and further dried for 8 hours.

Patent Document 1: Japanese Patent Laid-Open No. 2003-2997

Disclosure of the invention

Problems to be solved by the invention

[0003] In the pellet manufacturing method disclosed in Patent Document 1, since the pellet is dried at 50 ° C for 20 hours with a dryer, the pellet is almost completely dried, and a part of the starch contained in the pellet is glued. When the gelatinized starch is hardened, the pellet may be extremely hardened. When pellets hardened by gelatinized starch are put into an extruder for foam production, the pellets cannot be crushed by the screw of the extruder, and the pellet bites into the screw of the extruder, and the screw cylinder Cause malfunction. In addition, even if the gelatinized starch pellets are heated with an extruder heater, the pellets cannot be melted from V, and the foam itself cannot be made.

[0004] An object of the present invention is to provide a pellet manufacturing method capable of reducing moisture contained in pellets without gelatinizing starch at an early stage. Another object of the present invention is to provide a pellet manufacturing method capable of producing a pellet that collapses at a low pressure while maintaining a predetermined shape. To provide a law.

Means for solving the problem

[0005] A method for producing pellets according to the present invention involves granulating a water-containing mixture made by kneading a predetermined amount of paper powder, starch and water, and processing the mixture into a plurality of pellets having a predetermined shape. And a drying step for reducing moisture contained in the pellets, the drying step being disposed inside the unit and having a pellet inlet and outlet, and the pellets from the unit inlet. It is equipped with a belt conveyor that transports it to the discharge port and a heat source that raises the internal temperature of the unit. It is in the range of lmZs, and the internal temperature of the unit is kept in the range of 45-50 ° C by the heat source.

[0006] As an example of the pellet manufacturing method, in the pellet after passing through the drying step, the paper powder and the starch are bonded to each other by hydrogen bonding while the paper powder and the starch are dispersed substantially uniformly. The moisture content is in the range of 12.0 to 20.0%, and the collapse pressure is in the range of 100 to 490N.

[0007] As another example of the pellet manufacturing method, in the granulation step, alcohol that takes away frictional heat at the time of granulation of the water-containing mixture is injected by heat of vaporization, and the temperature of the water-containing mixture in the granulation step is Hold at 35-45 ° C.

[0008] As another example of the pellet manufacturing method, the mixing ratio of the alcohol injected in the granulation step is in the range of 2.0 to 20.0% by weight with respect to the total weight of the water-containing mixture.

[0009] As another example of the pellet manufacturing method, the alcohol content of the pellets after the drying step is in the range of 0.5 to 15.0%.

[0010] As another example of the pellet manufacturing method, a granulation process force includes a screw extruder having a porous die attached to a tip portion thereof, and a screw compressor connected to the screw extruder. The moisture-containing mixture is extruded into a noodle-like mixture by being extruded from a perforated die cutter, and while the noodle-like mixture is conveyed by the screw competitor, the screw-compressor casing and the screw As it enters the gap, it is cut by a screw and cast into a plurality of pellets.

[0011] As another example of the pellet manufacturing method, with respect to the total weight of the paper powder and starch The mixing ratio of the paper powder is in the range of 60 to 80% by weight, the mixing ratio of the starch to the total weight of the paper powder and starch is in the range of 20 to 40% by weight, and the average particle size of the paper powder is 50 to In the range of 200 μm, the average particle size force of the powder is in the range of 5 to 150 μm.

The invention's effect

[0012] According to the method for producing pellets, which is effective in the present invention, the pellets are placed on the belt conveyor in the drying step, the belt conveyor is operated at a traveling speed of 0.02 to 0.1 lmZs, and the entrance locuser is also moved on the belt conveyor. Pellets moving toward the discharge port are dried in an atmosphere of about 10 to 1000 seconds and 45 to 50 ° C, so the moisture contained in the pellets can be reduced in a short time and the pellets can be dried for a long time. Can prevent starch gelatinization. In this pellet manufacturing method, the starch contained in the pellet is not gelatinized, so that it is possible to produce a pellet that collapses under pressure while maintaining a predetermined shape. Even if the pellets produced by this pellet production method are put into an extruder for producing foamed members, the pellets are easily disintegrated by the screws of the extruder, and the screw of the extruder is blocked by the pellets. Will not fail. In addition, since the pellets are easily melted by heating with the heater of the extruder, the foamed member can be reliably made using the extruder.

[0013] With this pellet manufacturing method, paper powder and starch are dispersed substantially uniformly, and pellets in which paper powder and starch are bonded to each other by hydrogen bonding without gelatinizing the starch can be produced. It is possible to produce pellets that can be reliably disintegrated at low pressure while holding In addition, this pellet manufacturing method operates the belt conveyor at a travel speed of 0.02-0.lmZs, and moves the pellet moving on the belt competitor with the entrance loca moving toward the discharge port for about 10 to: L000 seconds and 45 By drying in an atmosphere of ~ 50 ° C, pellets with a moisture content in the range of 12.0 to 20.0% and a collapse pressure in the range of 100 to 490N can be made, and the pellets must be completely dried This can prevent the hardening of the pellets and the increase of the collapse pressure due to the above. Even if the pellets produced by this pellet production method are put into an extruder for producing foamed parts, the pellets are easily broken by the screw of the extruder, and the pellet causes the screw screw cylinder of the extruder to break down. Furthermore, since the pellets are easily melted by heating with the heater of the extruder, the foamed member can be reliably made using the extruder. [0014] In the pellet production method in which alcohol is added in the granulation step and the temperature of the water-containing mixture is maintained at 35 to 45 ° C, the heat of vaporization of the alcohol may take away frictional heat during granulation of the mixture. Therefore, the local increase in the temperature of the mixture can surely prevent starch gelatinization during granulation. In this pellet manufacturing method, since the starch contained in the pellet does not gelatinize, it is possible to make a pellet that reliably collapses with low pressure while maintaining a predetermined shape. Even if the pellet made by this pellet manufacturing method is put into an extruder for producing foamed parts, the pellet easily collapses with the extruder screw and the pellet causes the screw screw cylinder of the extruder to fail. Moreover, since the pellets are easily melted by heating with the heater of the extruder, the foamed member can be reliably made by using an extruder.

[0015] The pellet production method in which the mixing ratio of the alcohol injected in the granulation step is in the range of 2.0 to 20% by weight with respect to the weight of the water-containing mixture is as follows. Since the frictional heat of the mixture can be reliably taken away, starch gelatinization during granulation can be surely prevented. In this pellet manufacturing method, since the starch contained in the pellet does not gelatinize, it is possible to produce a pellet that reliably collapses under low pressure while maintaining a predetermined shape. Even if the pellets produced by this pellet manufacturing method are put into an extruder for producing foamed parts, the pellets can be easily disintegrated by the screw of the extruder, and the screw screw cylinder of the extruder fails due to the pellet. Furthermore, since the pellets are easily melted by heating with the heater of the extruder, the foamed material can be reliably made using the extruder.

[0016] The pellet production method in which the alcohol content of the pellets after passing through the drying step is in the range of 0.5 to 15.0% is a method for producing a foamed member using the pellets produced by the production method. As the alcohol with a lower boiling point than water is immediately vaporized inside the extruder for producing foamed parts, the pressure inside the cylinder rises, so the pressure inside the cylinder is higher than when only water is used for vaporization. The foaming efficiency in the extruder can be improved.

[0017] A granulation process force screw extruder and a screw compressor are provided. While the noodle-like mixture is conveyed by the screw compressor, the screw compensator casing and screw are provided. In a pellet manufacturing method in which a plurality of pellets are cut into a plurality of pellets while entering a gap between them, a noodle-like mixture having a predetermined viscosity is made into a predetermined length via a screw of a screw converter. It can be cut and a plurality of pellets having substantially the same shape can be reliably produced.

Brief Description of Drawings

FIG. 1 is a block diagram showing steps of a pellet manufacturing method.

FIG. 2 is a diagram showing an example of a ribbon mixer, a stirring hopper, a granulator, and a dryer.

FIG. 3 is a diagram showing the granulator from the front.

FIG. 4 is a perspective view of a screw competitor.

FIG. 5 is a perspective view of a pellet made by the pellet manufacturing method.

FIG. 6 is a process schematic diagram showing an example of a method for producing a foamed member made using the pellets of FIG.

7 is a perspective view of a foam member made by the manufacturing method of FIG.

Explanation of symbols

[0019] 10 Crushing process

11 Kneading process

12 Granulation process

13 Drying process

14 Ribbon mixer (first kneader)

15 Stirring hopper (second kneader)

17 Kneading tank (1st kneading tank)

18 axes (1st axis)

19 Stir ribbon (first blade)

26 Kneading tank (second kneading tank)

27th axis (second axis)

28 Stirring blade (second blade)

34 Granulator

36 screw extruder 37 Screw competition

42 Tip

43 perforated dies

47 Casing

48 screw

54 Dryer

56 Entrance

57 outlet

58 units

59 Benoleto conveyor

60 Heater (heat source)

P to Tsu

BEST MODE FOR CARRYING OUT THE INVENTION

[0020] The details of the pellet manufacturing method according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing each step of the pellet manufacturing method, and FIG. 2 is a diagram showing an example of the ribbon mixer 14, the stirring hopper 15, the granulator 34, and the dryer 54. FIG. 3 is a diagram showing the front force of the granulator 34, and FIG. 4 is a perspective view of the screw competitor 37. In Figs. 2 and 3, the front-rear direction is indicated by arrow A (Fig. 2 only), the vertical direction is indicated by arrow B, and the horizontal direction is indicated by arrow C (Fig. 3 only). In Fig. 2, the conveying direction of the mixture and pellets P is indicated by arrows. The pellet manufacturing method comprises a granulation step 12 for granulating a water-containing mixture and covering the mixture into a plurality of pellets P having a predetermined shape, and a drying step 13 for reducing the water contained in the pellet P. Yes. This production method includes a pulverizing step 10 for producing paper powder and starch powder, and a kneading step 11 for kneading paper powder and starch powder together with water and alcohol to form a water-containing mixture.

[0021] The pulverization step 10 is divided into a preliminary pulverization step and a fine pulverization step. A coarse pulverizer (not shown) is installed in the preliminary pulverization process, and a fine pulverizer (not shown) is installed in the fine pulverization process. In the crushing process 10, paper pulverized material is made using a coarse pulverizer and paper powder is made using a fine pulverizer. In addition, starch powder is made using a fine grinder. Forecast An example of making paper powder from the pre-grinding process and the fine grinding process is as follows. At least one of a predetermined size of paper and pulp is put into a coarse pulverizer, the paper and pulp are processed into a pulverized paper of several tens of centimeters to several millimeters by the coarse pulverizer, and then the pulverized paper is put into a fine pulverizer The paper pulverized material is processed into paper powder of tens to hundreds of meters. An example of producing starch powder from a fine pulverization step is to put bulk starch into a fine pulverizer and process the bulk starch into starch powder of several meters to several hundred meters. For the coarse pulverizer, a jaw crusher, a gyratory crusher, a corn crusher, a non-mark crusher, and a Ronore crusher can be used. A ball mill, a medium stirring mill, or a roller mill can be used for the fine pulverizer. As the ball mill, a rolling ball mill, a vibrating ball mill, a planetary ball mill, or a tower ball mill can be used. As the medium agitation mill, an agitation tank mill or air mill can be used. As the roller mill, a centrifugal roller mill or a hydraulic roller mill can be used.

[0022] As the paper, at least one of virgin paper and used paper can be used. Used paper can be used as newspaper waste, magazine waste paper, printing waste paper, packaging waste paper, cardboard waste paper, OA waste paper, and so on. Virgin paper can also be broken paper and waste paper generated when it is produced. As the paper powder, it is also possible to use a cellulose-based powder obtained by grinding at least one of hardwood pulp and softwood pulp into a powder by a grinding process. The pulp may be any of mechanical pulp, chemical mechanical pulp, semi-chemical pulp, and chemical pulp. For paper and pulp, it is preferable to use those containing no chlorine and no fluorescent bleach. If paper or pulp contains chlorine or a fluorescent bleach, dechlorinate or defluorinate bleach to eliminate chlorine and fluorescent bleach.

[0023] As the starch, at least one of raw material starch and processed starch can be used. As the raw material starch, it is preferable to use corn starch, which is capable of using at least one of corn starch, potato starch, wheat starch, rice starch and tapio power starch. Processed starch includes starch derivatives, starch degradation products, and pregelatinized starch. As the starch derivative, at least one of etherified starch, esterified starch, and crosslinked starch can be used. Starch degradation products include at least roasted dextrin and pre-tissue gum, oxygen-modified dextrin, acid-decomposed starch, and oxidized starch. One can be used. Tap water is used for water. As the alcohol, at least one of methyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, and active aluminum alcohol can be used.

[0024] In the kneading step 11, a ribbon mixer 14 (first kneader) and a stirring hopper 15 (second kneader) located below the mixer 14 in the vertical direction (downstream side) are installed. The ribbon mixer 14 is mounted on the equipment tower 16. The ribbon mixer 14 includes a kneading tank 17 (first kneading tank), a shaft 18 (first shaft), and a stirring ribbon 19 (first blade). The kneading tank 17 has a peripheral wall 20 that forms an arc when the upward force is directed downward, a front and rear wall 21 positioned in front of and behind the peripheral wall 20, and an upper opening 22. In the kneading tank 17, a storage space 23 surrounded by the walls 20, 21 is defined. A duct 24 connected to the stirring hopper 15 is connected to the bottom of the peripheral wall 20. The shaft 18 is located in the accommodation space 23 of the kneading tank 17 and extends in the front-rear direction (one direction), and both ends thereof are supported by the bearings 25 through the front and rear walls 21 of the kneading tank 17. The shaft 17 is rotated in the clockwise direction and the counterclockwise direction indicated by the arrow D by driving an electric motor (not shown). The stirring ribbon 19 extends in a substantially spiral shape in the front-rear direction so as to surround the shaft 18. As indicated by arrow F, paper powder and starch are poured into the storage space 23 of the kneading tank 17 and water and alcohol are injected therein. The stirring ribbon 19 is rotated clockwise and counterclockwise by the rotation of the shaft 18, and the paper powder and starch are kneaded together with water and alcohol while stirring the paper powder, starch, water and alcohol. In the kneading step 11, a paddle mixer or a screw mixer can be used instead of the ribbon mixer 14.

The stirring hopper 15 is disposed below the equipment tower 16. The stirring hopper 15 includes a kneading tank 26 (second kneading tank), a shaft 27 (second shaft), and a stirring blade 28 (second blade). The kneading tank 26 has a peripheral wall 29 extending in a funnel shape from above to below, an upper wall 30 located above the peripheral wall 29, and a lower outlet 31 that can be opened and closed. In the kneading tank 26, a storage space 32 surrounded by a peripheral wall 29 is defined. The shaft 27 is located in the accommodation space 32 of the kneading tank 26 and extends in the vertical direction (direction intersecting with one direction). The upper end of the shaft 27 penetrates the upper wall 30 of the kneading tank 26 and the upper and lower ends of the bearing 33 It is supported. The shaft 27 is a motor drive (not shown). Rotates in the clockwise and counterclockwise directions indicated by arrow E. The stirring blades 28 are arranged in at least two stages in the vertical direction, are located outward in the direction around the shaft 27, and extend so as to form a perfect circle in the direction around the shaft 27. In the space 32 of the kneading tank 26, the mixture also flows into the mixing tank 17 and alcohol is injected. The stirring blade 28 rotates clockwise and counterclockwise by the rotation of the shaft 27, and remixes the mixture together with the alcohol while stirring the mixture and the alcohol. In the kneading step 11, instead of the stirring hopper 15, a Po-mixer, a vacuum backflow mixer, a Nauta mixer, a high sludger, a Weirich mixer, a Henschel mixer, a power mixer, a combimix, and a Shugi mixer can be used.

[0026] In the granulating step 12, a granulator 34 is installed. The granulator 34 is placed on a pedestal 35. The granulator 34 is formed of a screw extruder 36 (screw horizontal extruder) and a screw compressor 37 that has a force S connected to the extruder 36. Between the agitation hopper 15 and the granulator 34, a belt compressor 38 is arranged. The extruder 36 includes a hopper 39 into which a moisture-containing mixture flows, a cylinder 40 connected to the hopper 39, two screws 41 that are rotatably installed inside the cylinder 40, and a side of the tip 42 of the cylinder 40. It is formed from a perforated die 43 attached. The mixture flows from the compressor 38 into the hopper 39 of the extruder 36, and alcohol is injected as shown by an arrow G. The screw 41 is rotated by the drive of the electric motor 45 to knead the mixture and the alcohol that has entered the cylinder 40 and pushes the mixture while pressing it toward the tip end 42 from the rear end force 45. The perforated die 43 has a plurality of circular through holes 46, and the mixture pressed by the screw 41 is covered in a noodle shape by the through holes 46.

[0027] The screw compressor 37 is disposed below the extruder 36 in the vertical direction, and is formed by a casing 47 (trough) that is long in the lateral direction and a screw 48 that is rotatably installed inside the casing 47. ing. The screw 48 is rotated by the drive of the electric motor 49, and conveys the noodle-like mixture that has entered the casing 47 toward the outlet 51 from the inlet 50 of the casing 47. A slight gap is formed between the inner wall 52 of the casing 47 and the tip of the spiral portion 53 of the screw 48. The noodle-like mixture enters the gap between the inner wall 52 of the casing 47 and the tip of the spiral portion 53 of the screw 48, while the screw 48 It is conveyed from the inlet 50 to the outlet 51 of the single 47 by force. The tip of the spiral portion 53 of the screw 48 functions as a tooth for cutting the noodle-like mixture, and the noodle-like mixture that has entered the gap is cut into a predetermined length and cast into a plurality of pellets P. Therefore, the noodle-like mixture is processed into a plurality of pellets P while being conveyed from the inlet 50 force of the casing 47 to the outlet 51.

[0028] In the drying step 13, a dryer 54 for drying the pellets P produced in the granulation step 12 is installed. Between the granulator 34 and the dryer 54, a belt competitor 55 is disposed. The dryer 54 includes a unit 58 having an inlet 56 and an outlet 57, a belt compressor 59 installed in the unit 58, a heater 60 (heat source) that heats the air to produce hot air, and a heating It is formed by a blower 61 that blows hot air produced by the vessel 60 and a blower 62 that discharges the hot air to the outside of the unit 58. The belt conveyor 59 extends between the inlet 56 and the outlet 57 of the unit 58. A number of fine through holes (not shown) are formed in the belt competitor 59. The heater 60 and the blower 61 are installed between the belt competitors. The exhaust fan 62 is installed in the upper part of the unit 58.

[0029] The pellets P that have been sequentially dropped onto the belt compressor 55 from the outlet 51 of the casing 47 are conveyed to the dryer 54 by the conveyor 55. Pellets P transported to the entrance 56 of the unit 58 by the competitor 55 move from the entrance 56 of the unit 58 to the belt compressor 59 inside the unit 58, move on the belt compressor 59 and from the entrance 56 of the unit 58. Head to outlet 57. The belt conveyor 59 slowly conveys the pellet P at a predetermined speed from the inlet 56 to the outlet 57 of the unit 58. The hot air produced by the heater 60 is blown from the lower side of the belt compressor 59 toward the upper side of the unit 58 by the blower 61 as indicated by an arrow H. The warm air passes through the through hole of the compressor 59 and circulates inside the unit 58, and is then discharged outside the unit 58 by the exhaust fan 62 as indicated by an arrow I. In the drying step 13, the pellet P moving on the belt compressor 59 is heated by the hot air, and while it enters the outlet 58 of the unit 58 from the inlet 56 force, one of the moisture and alcohol contained in the pellet P is discharged. The part vaporizes.

[0030] The procedure for producing pellets P by this production method will be described as follows. At least one of paper and pulp is put into the coarse pulverizer, and the paper and pulp are After coarsely pulverizing to make a pulverized paper, the pulverized paper is put into a fine pulverizer, and the pulverized paper is finely pulverized with a fine pulverizer to make paper powder. The paper panda is collected by a dust collector (not shown) and temporarily stored in a storage hopper (not shown). Bulk starch is pulverized by a pulverizer to make starch powder. The starch powder is collected by a dust collector (not shown) and temporarily stored in a storage hopper (not shown). Paper powder and starch powder are put into the stirring tank 17 of the ribbon mixer 14 from the containing hopper, and water and alcohol are poured into the stirring tank 17 at the same time. In the agitation tank 17, paper powder, starch, water and alcohol are agitated by the agitation ribbon 19 of the mixer 14, and the paper powder and starch are kneaded with water and alcohol to have a predetermined fluidity. Is made.

[0031] The shaft 18 of the ribbon mixer 14 rotates approximately half of the kneading time in the clockwise direction, and rotates the remaining half of the kneading time in the counterclockwise direction. As a result, the stirring ribbon 19 rotates in the clockwise direction and the counterclockwise direction. In the mixer 14, paper powder, starch, water, and alcohol are stirred and kneaded by the stirring ribbon 19 in two directions, clockwise and counterclockwise. Inside the agitation tank 17, paper powder or starch that does not dissolve in water and does not exhibit fluidity rubs against the agitation ribbon 19 and generates frictional heat.The heat of vaporization of alcohol takes away frictional heat. Does not increase the temperature of the mixture. The temperature of the mixture during kneading in the kneading tank 17 is maintained at 10 to 30 ° C. by the heat of vaporization of alcohol. Therefore, the starch does not gelatinize in the stirring and kneading process of the mixer 14. The shaft 18 may rotate only in either the clockwise direction or the counterclockwise direction.

[0032] The kneading time of the paper powder, starch, water and alcohol by the mixer 14 is 5 to 20 minutes. The rotation speed of the shaft 18 is in the range of 20min ^_1 or more and 200 min ^_1 below. If the rotational speed of the shaft 18 is less than 20 ^min_1 , the paper powder, starch, water, and alcohol cannot be sufficiently stirred and kneaded through the stirring ribbon 19, and a mixture in which the paper powder and starch are mixed substantially uniformly is not obtained. I can't make it. Kneading time exceeds 20 minutes, the rotational speed of the shaft 18 exceeds 200 min ^_1, if a portion of the starch in the free-fitting frictional heat frictional heat is generated in the stirring-kneading process of the mixer 14 will be gelatinization is there. In the mixer 14, the kneading time and the rotation speed of the shaft 18 are within the above ranges. The generation of frictional heat between the paper powder or starch and the stirring ribbon 19 can be prevented, and the gelatinization of starch during the stirring and kneading process of the mixer 14 can be reliably prevented.

[0033] The mixing ratio of water to the total weight of the paper powder and starch powder (the ratio of water injected into the stirring tank 17) is in the range of 20 wt% or more and 50 wt% or less. If the mixing ratio of water is less than 20% by weight, paper powder and starch powder cannot be sufficiently kneaded, and a mixture in which paper powder and starch are dispersed almost uniformly cannot be made. In addition, the viscosity of the mixture is significantly increased by kneading in the granulator 34 (screw extruder 36), and almost no fluidity is exhibited, so that the mixture is made. Therefore, in the granulation step 12, the mixture is fragile. In some cases, it may not be possible to make a pellet with a predetermined shape. When the mixing ratio of water exceeds 50% by weight, kneading in the granulator 34 (screw extruder 36) cannot impart an appropriate viscosity to the mixture, and the viscosity of the mixture is significantly reduced. In 12 there are cases where the pellet itself cannot be made. In this pellet manufacturing method, since the mixing ratio of water with respect to the total weight of the paper powder and the starch powder is in the above range, it is possible to produce a mixture having an appropriate viscosity and an appropriate fluidity in the granulation step 12. It is possible to produce pellets P having a predetermined shape in which the paper powder and starch are mixed almost uniformly.

[0034] The temperature of water injected into the ribbon mixer 14 is in the range of 0 ° C or higher and 30 ° C or lower.

If the temperature of the water is less than 0 ° C, the water freezes and the alcohol is insufficiently vaporized, and the paper powder and starch powder cannot be sufficiently kneaded through the water. It is not possible to make a mixture in which the and are dispersed almost uniformly. When the temperature of the water exceeds 30 ° C, the temperature of the mixture rises, and the alcohol vaporizes early, and the heat of vaporization of the alcohol cannot be used to remove the frictional heat. Part of the starch may be gelatinized by frictional heat. When part of the starch is gelatinized, it adheres to the stirring ribbon 19 and the stirring blade 28, and the kneading function in the ribbon mixer 14 and the stirring hopper 15 is lowered so that the paper powder and starch cannot be mixed uniformly. . In this pellet manufacturing method, the temperature of the water to be injected is within the above range, so that starch gelatinization can be prevented and pellet P in which the paper powder and starch are mixed almost uniformly can be made. .

[0035] The mixing ratio of the alcohol injected into the ribbon mixer 14 is in the range of 2 wt% or more and 30 wt% or less with respect to the weight of the injected water. Alcohol mixing ratio is 2% If it is less than%, the heat of vaporization of the alcohol cannot be fully utilized, and the frictional heat between the paper powder and starch and the stirring ribbon cannot be taken away, so that part of the starch may be gelatinized. is there. In this pellet manufacturing method, since the mixing ratio of the alcohol injected into the mixer 14 is in the above range, the frictional heat can be surely removed, and the starch is surely prevented from gelatinizing during the stirring and kneading process in the mixer 14. be able to.

[0036] When the kneading time in the ribbon mixer 14 has elapsed, the water-containing mixture flows from the stirring tank 17 through the duct 24 into the stirring tank 26 of the stirring hopper 15, and at the same time, alcohol is injected into the stirring tank 26. In the stirring tank 26, the mixture is stirred and kneaded again by the stirring blade 28 of the stirring hopper 15 together with the alcohol. The shaft 27 of the stirring hopper 15 rotates approximately half of the kneading time in the clockwise direction, and rotates the remaining half of the kneading time in the counterclockwise direction. Thereby, the stirring blade 28 rotates in the clockwise direction and the counterclockwise direction. In the hopper 15, the mixture and alcohol are kneaded by the stirring blade 28 in two directions, a clockwise direction and a counterclockwise direction. Inside the agitation tank 26, the paper powder and starch forming the mixture rub against the agitation blade 28 and generate frictional heat.The heat of vaporization of alcohol takes away frictional heat, so the temperature of the mixture rises due to frictional heat. There is nothing. The temperature of the mixture during kneading in the kneading tank 26 is maintained at 10 to 30 ° C. by the heat of vaporization of alcohol. Therefore, the starch does not gelatinize in the stirring kneading process of the stirring hopper 15. The shaft 27 may rotate only in either the clockwise direction or the counterclockwise direction.

[0037] The kneading time of the mixture by the stirring hopper 15 is 5 to 20 minutes. The rotation speed of the shaft 27 is in the range of 20min ^_1 or more and 200 min ^_1 below. If the rotational speed of the shaft 27 is less than 20 min ^_1 , the mixture and alcohol cannot be sufficiently stirred and kneaded through the stirring blade 28, and a mixture in which paper powder and starch are mixed almost uniformly cannot be formed. . Kneading time exceeds 20 minutes, the rotational speed of the shaft 27 exceeds 200 min ^_1, part of the starch in the frictional heat is generated in the stirring-kneading process of stirring the hopper 1 5 Ekigu frictional heat is gelatinized Mau There is a case. In the hopper 15, the kneading time and the rotational speed of the shaft 27 are within the above ranges, so that it is possible to prevent the generation of frictional heat between the mixture and the stirring blade 28 due to kneading at a high speed or long-time kneading. Reliably prevents starch gelatinization during 15 stirring and kneading processes You can

[0038] The mixing ratio of paper powder to the total weight of paper powder and starch powder combined is in the range of 60 wt% to 80 wt%. The mixing ratio of starch powder to the total weight is in the range of 20% to 40% by weight. If the mixing ratio of the paper powder is less than 60% by weight and the mixing ratio of the starch powder exceeds 40% by weight, the ratio of starch in the mixture will increase more than necessary, and part of the starch will be caused by frictional heat during kneading. There are cases where gelatinization occurs, and paper powder and starch may not be mixed substantially uniformly. When the mixing ratio of the paper powder exceeds 80% by weight and the mixing ratio of the starch powder is less than 20% by weight, the ratio in the non-self-adhesive paper powder mixture increases more than necessary, and the granulator 34 ( A predetermined viscosity may not be imparted to the mixture by kneading in a screw extruder 36), and the viscosity of the mixture may be significantly reduced, making it impossible to produce pellets of a predetermined shape. In this pellet manufacturing method, the mixing ratio of paper powder and starch powder to the total weight of paper powder and starch powder combined is within the above range. And a pellet P having a predetermined shape in which paper powder and starch are almost uniformly mixed.

[0039] The paper powder has an average particle size in the range of 50 µm or more and 200 µm or less. The average particle size of the pulp and paper Uda one is less than _{50 mu m,} the paper powder further require multiple grinding steps in order to process the particle size of less than 50 mu m, the production cost of the pellets P rises . When the average particle size of the paper powder exceeds 200 μm, the paper powder that does not exhibit fluidity deteriorates the kneading function of the ribbon mixer 14 and the stirring hopper 15, and the paper powder is fed to the ribbon mixer 14 and the stirring hopper 15. And starch powder cannot be mixed almost uniformly, and paper powder and starch may be biased in the mixture. Starch powder has an average particle size in the range of 5 μm to 150 μm. When the average particle size of the starch powder is less than 5 μm, a pulverization process for processing the bulk starch into a particle size of less than 5 m is required, and the production cost of the pellet P increases. When the average particle size of the starch powder exceeds 150 m, starch that does not exhibit fluidity deteriorates the kneading function of the ribbon mixer 14 and the stirring hopper 15, and the paper powder and starch are fed into the ribbon mixer 14 and the stirring hopper 15. Mix the powder almost uniformly. In some cases, the mixture cannot be mixed, and paper powder and starch may be biased in the mixture. In this pellet manufacturing method, the average particle size of the paper powder and the starch powder is in the above-mentioned range, so that the cost is low and the pellet P in which the paper powder and the starch are almost uniformly mixed can be produced. .

[0040] The mixing ratio of the alcohol injected into the stirring hopper 15 is in the range of 2 wt% to 15 wt% with respect to the weight of the injected water. If the mixing ratio of the alcohol is less than 2% by weight, the heat of vaporization of the alcohol cannot be fully utilized, and the frictional heat between the mixture and the stirring blade 28 cannot be removed. There is a case. In this pellet manufacturing method, since the mixing ratio of the alcohol injected into the stirring hopper 15 is within the above range, the frictional heat can be surely removed, and the starch is gelatinized during the stirring and kneading process in the stirring hopper 15. It can be surely prevented. Further, since the mixture is re-kneaded through alcohol, paper powder and starch can be dispersed substantially uniformly in the mixture.

[0041] In the ribbon mixer 14 and the stirring hopper 15, while the mixture is stirred and kneaded, the injected alcohol is vaporized and the water contained in the mixture is slightly vaporized. The moisture content of the moisture-containing mixture after being kneaded by the stirring hopper 15 is in the range of 30% to 34%. Therefore, the water-containing mixture does not become liquid or gel. Here, the ratio of the water-containing mixture was calculated by {(total weight of the mixture, total weight after drying of the mixture) total weight of the Z mixture after drying} X 100.

[0042] In the kneading step 11, paper powder and starch powder are kneaded together with water and alcohol by rotating the stirring ribbon 19 attached to the shaft 18 extending in the front-rear direction in two directions, the clockwise direction and the counterclockwise direction. Furthermore, since the water-containing mixture is re-kneaded with the alcohol by rotating the stirring blade 28 attached to the shaft 27 extending in the vertical direction in two directions, the clockwise direction and the counterclockwise direction, the mixture is mixed in a total of four directions. Kneaded. Therefore, in the kneading step 11, the paper powder and starch can be sufficiently stirred and kneaded through water or alcohol, and a water-containing mixture in which the paper powder and starch are almost uniformly mixed can be formed. In the kneading step 11, if the rotational speed of the shafts 18 and 27 is reduced to prevent the generation of frictional heat and the gelatinization of starch can be prevented, only water is poured into the stirring tank 17, and the stirring tank 17 and It is also possible to omit the injection of alcohol into the agitation tank 26.

[0043] When the kneading time in the stirring hopper 15 elapses, the lower outlet 31 of the hopper 15 opens, and the water-containing mixture sequentially falls onto the belt compressor 38. The mixture is conveyed to the screw extruder 36 by the belt conveyor 38, is introduced into the hopper 39 of the extruder 36, and enters the cylinder 40 from the hopper 39. Alcohol is injected into the hopper 39 of the extruder 36. The mixture is kneaded and pressed with alcohol by the rotation of the screw 41, and is pushed out from the rear end 44 of the cylinder 40 toward the front end 42, and passes through the through hole 46 of the perforated die 43 to form a plurality of noodles. It will be overwhelmed. The mixture kneaded by the screw 41 of the extruder 36 exhibits an appropriate viscosity and an appropriate fluidity. The viscosity of the mixture after being kneaded by the extruder 36 is in the range of lOPa 's or more and 10 ⁴ Pa' s or less, preferably 10 ² Pa 's or more and 10 ³ Pa' s or less. . When the viscosity of the mixture is less than lOPa 's, the viscosity of the mixture is insufficient, the mixture flows easily, and when the viscosity of the mixture exceeds 10 ⁴ Pa · s, the mixture with high viscosity is easily broken. Therefore, the mixture cannot be processed into a noodle shape, and pellets having a predetermined shape cannot be produced in the granulation step 12. In this pellet manufacturing method, since the viscosity of the mixture after being kneaded by the extruder 36 is in the above range, pellets P having a predetermined shape that the mixture does not flow or become brittle in the granulation step 12 are obtained. Pellet P can retain its form while being reliably manufactured.

The noodle-like mixture enters the casing 47 from the inlet 50 of the casing 47 of the screw compressor 37 while dropping from the perforated die 43. As the screw 48 rotates, the noodle-like mixture moves from the inlet 50 of the casing 47 toward the outlet 51 and advances into the gap between the inner wall 52 of the casing 47 and the tip of the spiral portion 53 of the screw 48. It is cut into a predetermined length by the tip of the spiral portion 53 of the screw 48, and becomes a pellet P containing moisture and alcohol. The pellets P are sequentially dropped from the outlet 51 of the casing 47 onto the belt compressor 55 and are conveyed to the dryer 54 by the belt conveyor 55. The mixing ratio of the alcohol injected into the granulator 34 (screw extruder 36) is in the range of 2% by weight to 20% by weight with respect to the total weight of the water-containing mixture. When the mixing ratio of alcohol is less than 2% by weight, most of the alcohol is vaporized in the drying step 13. Thus, the pellet P after the drying step 13 does not contain alcohol. When the mixing ratio of alcohol exceeds 20% by weight, the viscosity of the mixture is lowered by alcohol and the pellet itself cannot be made.

[0045] Pellets P are transported to the entrance 56 of the unit 58 by the belt conveyor 55, and then moved from the conveyor 55 onto the belt conveyor 59 installed inside the unit 58. 56 port Forced to the discharge port 57 and conveyed. Pellets P are heated by the warm air passing through the through hole of the compressor 55 or the warm air circulating inside the unit 58, and are included in the inlet 58 of the unit 58, the discharge port 57 〖 Some of the moisture and alcohol that is vaporized. Here, the internal temperature of the unit 58 is maintained at a temperature at which the moisture contained in the pellet P can be reduced and the starch forming the pellet P is not gelatinized. Specifically, it is maintained in the range of 40 ° C or higher and 50 ° C or lower, preferably 45 ° C or higher and 50 ° C or lower. If the internal temperature of the unit 58 is less than 40 ° C, the moisture contained in the pellet P will not evaporate and the moisture cannot be reduced. If the internal temperature of unit 58 exceeds 50 ° C, pellet P will be heated more than necessary, and the moisture contained in pellet P will be greatly reduced. Also, the starch may be gelatinized and the pellet P may become extremely hard due to the solidified starch.

[0046] The traveling distance of the belt compressor 59 from the entrance 56 force to the outlet 57 of the unit 58 is in the range of lm to 20 m, and the traveling speed of the belt compressor 59 is 0.02 mZs or more and 0.1 lmZs or less. In the range of 0.03 mZs to 0.08 mZs, more preferably in the range of 0.04 mZs to 0.05 mZs. If the running distance of the belt compressor 59 is less than lm and the running speed of the conveyor 59 exceeds 0.1 lmZs, the moisture contained in the pellet P will not evaporate and the moisture cannot be reduced. If the traveling distance of the belt compressor 59 exceeds 20 m and the traveling speed of the conveyor 59 is less than 0.03 mZs, the heating time of the pellet P becomes long and the moisture and alcohol contained in the pellet P are greatly reduced. Also, starch may be gelatinized, and pellet P may be extremely hardened by the solidified starch. In this manufacturing method, since the internal temperature of the unit 58, the travel distance of the belt conveyor 59, and the travel speed of the belt compressor 59 are within the above-mentioned ranges, the belt moves on the belt compressor 59 toward the entrance 56 force discharge port 57. About 10 to 10 pellets By drying in an atmosphere of 45 to 50 ° C. for 00 seconds, moisture contained in the pellet P can be reduced moderately while preventing gelatinization of the starch forming the pellet P.

FIG. 5 is a perspective view of the pellet P produced by this manufacturing method. In the drying step 13, the moisture contained in the pellet P is vaporized, and the moisture S and the alcohol contained in the pellet P are reduced more than in the granulation step 12, and all the moisture and alcohol contained in the pellet P are vaporized. That is why Pellet P does not dry out completely. The pellet P that has undergone the drying step 13 contains starch and a predetermined amount of water and alcohol. The paper powder and starch forming the pellet P are bonded to each other by hydrogen bonding. Pellets P after the drying process 13 are made from a mixture of paper powder and starch mixed together almost uniformly! / Because it does not form a lump of paper powder or starch lump on it, the paper powder and starch are almost uniformly dispersed. Pellet P after passing through the drying step 13 has a moisture content in the range of 12.0% or more and 20.0% or less, and its alcohol content power is 0.5% or more and 15.0%. It is in the following range.

[0048] The pellet P that has undergone the drying step 13 is not gelatinized, contains a predetermined amount of moisture and alcohol, and paper powder and starch are bonded to each other by hydrogen bonding. It easily disintegrates at a pressure of 100 to 490N (collapse pressure) while maintaining its shape. Moreover, the starch contained in the pellet P is dissolved at a temperature of 150 to 190 ° C. As shown in Fig. 5, the pellet P has a substantially cylindrical shape, and its length L1 is in the range of 0.5 mm or more and 10. Omm or less, and its diameter L2 is 1. Omm or more and 5. Omm or less. Is in range. The pellet P has a bulk specific gravity in the range of 0.2 or more and 1.0 or less. Here, the bulk specific gravity is the specific gravity obtained by calculating the volume of the dimensional force of the formed pellet P and dividing the mass of the pellet P. In this pellet manufacturing method, pellets P are made by granulating a water-containing mixture that is sufficiently kneaded in four directions, so that paper P and starch are mixed almost uniformly and pellets P in which they are dispersed almost uniformly are made. be able to.

FIG. 6 is a schematic diagram showing an example of a manufacturing method of the foamed member 70 made using the pellet P of FIG. 5, and FIG. 7 shows the foamed member 70 made by the manufacturing method of FIG. FIG. The foam member 70 is manufactured by using an extruder 72 using a powder of pellets P and a polyolefin-based thermoplastic synthetic resin 71 as raw materials. The foam member 70 is attached to the tip 76 of the extruder 72. It is formed into a prismatic shape by an attached die (not shown).

[0050] As the polyolefin synthetic resin 71, either polypropylene or polyethylene, or a mixture of these in a predetermined ratio is used. As the polypropylene, at least one of polypropylene polymerized polypropylene, random polymerized polypropylene, homopolymerized polypropylene, and meta-polypropylene can be used. Polyethylene includes low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, meta-catalyst-catalyzed polyethylene, modified polyethylene, and ethylene butyl acetate.

At least one of (EVA) can be used. As the polypropylene, modified polypropylene obtained by reacting linear polypropylene, isoprene and a radical polymerization initiator can also be used. For the linear polypropylene, at least one of a propylene homopolymer, copolymer, block copolymer, and random copolymer can be used.

[0051] An example of a procedure for manufacturing the foamed member 70 by the extruder 72 will be described as follows. A plurality of pellets P and a predetermined amount of the thermoplastic synthetic resin 71 powder are charged into the hopper 73 of the extruder 72, and then water 75 is injected into the cylinder 74 of the extruder 72 in the middle stage force extruder 72. The pellet P and the thermoplastic synthetic resin 71 enter the cylinder 74 from the hopper 73 of the extruder 72 and are heated to 120 to 190 ° C. by a heater (not shown) of the extruder 72, while the cylinder 74 It is kneaded by rotation of a screw (not shown) installed inside. Inside the cylinder 74, the alcohol contained in the pellet P is instantly vaporized and the pressure inside the cylinder 74 increases. In addition, the water contained in the pellet P boils, whereby the starch is gelatinized and the pellet P melts, and the thermoplastic synthetic resin 71 melts, and the starch and the thermoplastic synthetic resin 71 melted together with the paper powder. And kneaded into a high temperature melt at a predetermined temperature. In the high-temperature melt, the paper powder is dispersed almost uniformly. The high-temperature melt gradually moves toward the tip 76 of the cylinder 74 while being pressed by the rotation of the screw. Note that the pellet P before being put into the extruder 72 is not gelatinized and easily collapses at a pressure of 100 to 490 N, and thus is immediately crushed by the screw of the extruder 72.

[0052] Water 75 injected from the middle stage of the extruder 72 is mixed into the high-temperature melt through a screw. It is. When water 75 is mixed into the melt, the water 75 instantly vaporizes depending on the temperature of the hot melt. When the water 75 is vaporized, a large number of bubbles are formed inside the melt, and when the die force attached to the tip 76 of the extruder 72 is also pushed out, the bubble expands. The melt expands (foams) at a predetermined magnification at a stretch, and the foam member 70 is made. The foamed member 70 from which the die force is also pushed out is solidified as its temperature gradually decreases. Inside the foam member 70, a starch that solidifies as the temperature drops forms a film that encloses the bubbles 77. The strength of the foamed member 70 is maintained by the solidified starch. Since all the alcohol contained in the pellet P is vaporized inside the cylinder 74, the foam member 70 does not contain alcohol. In the foam member 70, the paper powder is dispersed substantially uniformly. Since the average particle size of the paper powder forming the pellet P is in the range of 50 to 200 / ζ πι, the dispersion of the foamed material 70 in which the paper powder does not cause poor dispersion in the molten thermoplastic synthetic resin. No lump of paper powder is formed.

[0053] In this foamed member manufacturing method, by using the pellet ridge manufactured by the pellet manufacturing method, paper powder is dispersed substantially uniformly, and has excellent impact resistance and excellent cushioning properties. Foam member 70 can be made. In the foamed member manufacturing method, the pellet Ρ contains a predetermined amount (0.5-15.0%) of alcohol, so that alcohol having a boiling point lower than that of water is immediately vaporized inside the extruder 72. The pressure inside the cylinder can be increased, and high-temperature melt can be efficiently foamed. Even if the pellet Ρ produced by the above-described pellet manufacturing method is put into the extruder 72, the pellet Ρ easily collapses with the screw of the extruder 72, and the screw シリンダ cylinder of the extruder 72 fails due to the pellet Ρ. There is no. Further, since the pellets are easily melted by heating with the heater of the extruder 72, the foamed member 70 can be reliably made using the extruder 72.

[0054] The temperature of the high-temperature melt before mixing of water 75 in the extruder 72 is in the range of 120 ° C or higher and 190 ° C or lower, preferably 140 ° C or higher and 170 ° C or lower. . When the temperature of the melt is less than 120 ° C, the force depending on the amount of water 75 mixed in. The water 75 does not instantly vaporize inside the melt, resulting in insufficient foaming inside the melt. Many bubbles 77 cannot be created inside. When the temperature of the melt exceeds 190 ° C, the properties of thermoplastic resin, paper powder, and starch change with temperature. The foam member 70 itself is discolored by yellowing or darkening. The mixing ratio of water 75 to the total weight of the hot melt is in the range of 10 wt% to 30 wt%. If the mixing ratio of water 75 is less than 10% by weight, the vaporization of water 75 cannot be fully utilized, foaming inside the high-temperature melt is insufficient, and sufficient bubbles 77 are formed in the foam member 70. Therefore, the cushioning property of the foamed member 70 is deteriorated. When the mixing ratio of water 75 exceeds 30% by weight, the water 75 is not instantly vaporized, the foaming inside the high-temperature melt becomes insufficient, and sufficient bubbles 77 are not formed in the foam member 70, so that the foam member 70 The cushioning property of the is reduced.

[0055] The expansion ratio per unit volume of the foam member 70 is 5 to 60 times, preferably 5 to 30 times. If the expansion ratio is less than 5 times, the bubbles 77 are not sufficiently formed in the foam member 70, and the cushioning property of the foam member 70 becomes insufficient. When the expansion ratio exceeds 60 times, the strength of the foaming member 70 is significantly reduced, and the foaming member 70 may be damaged by a slight impact. The foam member 70 has 40% or more of closed cells and an average cell diameter of 2. Omm or less. The average cell diameter is preferably 1.5 mm or less, and the closed cell ratio is preferably 50% or more. The combustion calorie of the foam member 70 is in the range of 4500 to 6000 KcalZkg.

[0056] The mixing ratio of the thermoplastic synthetic resin to the total weight of the pellet P and the polyolefin-based thermoplastic synthetic resin is in the range of 20 wt% or more and 35 wt% or less. If the mixing ratio of the thermoplastic resin is less than 20% by weight, foaming in the high-temperature melt is insufficient, so that only a few bubbles 77 are formed in the foam member 70, and the tackiness of the foam member 70 is lowered. . When the mixing ratio of the thermoplastic synthetic resin exceeds 35% by weight, the ratio of the thermoplastic synthetic resin with higher calorie burn than paper powder and starch increases, the burned calorie of the foam member 70 increases, and the burned calorie is 6000kcalZkg. May be exceeded.

[0057] Since the foam member 70 contains paper powder and starch, compared with the case where only the thermoplastic synthetic resin is made of power, the incinerator is reduced during the incineration process. It will not hurt. By changing the mixing ratio of the paper powder and starch powder forming the pellet P, and the mixing ratio of the thermoplastic synthetic resin, the foaming member 70 can adjust the combustion calories within the above range. Foam member 70 is made of polyolefin without a benzene ring. In-line thermoplastic synthetic resin is used and it does not contain polystyrene resin. Therefore, only in the case of incineration, only carbon dioxide and carbon are generated, and it does not adversely affect the environment where smoke is not generated.

Claims

The scope of the claims

[1] A granulation step of granulating a water-containing mixture made by kneading a predetermined amount of paper powder, starch and water, and processing the mixture into a plurality of pellets of a predetermined shape; A drying step for reducing the generated moisture, the drying step being disposed inside the unit and having the pellet inlet and outlet, and the pellet from the unit inlet to the outlet. A belt conveyor for transporting and a heat source for raising the internal temperature of the unit; a travel distance of the belt compressor from the advance port to the discharge port is in a range of 1 to 20 m; and a travel speed of the belt compressor is 0.02 to 0 The pellet manufacturing method, which is in the range of lmZs, and is held in the range of 45-50 ° C by the internal temperature force of the unit by the heat source.

[2] In the pellets after passing through the drying step, the paper powder and the starch are bonded to each other by hydrogen bonding while the paper powder and the starch are substantially uniformly dispersed, and the water content is 12 The pellet production method according to claim 1, wherein the collapse pressure is in the range of 0 to 20.0% and in the range of 100 to 490N.

[3] In the granulation step, alcohol that absorbs frictional heat at the time of granulation of the moisture-containing mixture is injected by heat of vaporization, and the temperature of the mixture in the granulation step is maintained at 35 to 45 ° C. The pellet manufacturing method according to claim 1 or claim 2.

[4] The pellet manufacturing method according to claim 3, wherein a mixing ratio of the alcohol injected in the granulation step is in a range of 2.0 to 20.0% by weight with respect to a total weight of the moisture-containing mixture. .

[5] The method for producing a pellet according to any one of claims 3 and 4, wherein the pellet has an alcohol content in the range of 0.5-15. 0% after the drying step.

[6] The granulation step includes a screw extruder having a porous die attached to a tip portion thereof, and a screw compressor connected to the screw extruder. In the granulation step, the water-containing mixture is the porous It is processed into a noodle-like mixture by being extruded from a die cutter, and enters the gap between the screw companion casing and the screw while the noodle-like mixture is conveyed by the screw competitor. 6. Any one of claims 1 to 5, wherein the pellets are cut by the screen and covered into a plurality of pellets. The pellet manufacturing method of crab.

The paper mixing ratio of the paper powder to the total weight of the powder and the starch, 60-80 wt% range, mixing the split force 20 to 40 weight starch relative to the total weight of the paper powder and the starch ⁰ / in the range of _0, the average particle diameter of the paper powder, the range of 50 to 200 m, an average particle size of the starch, either by Aru claim 1 Nai in the range of 5 to 150 111 claims 6 The pellet manufacturing method as described in 2.