JP2003340823A - Method and apparatus for manufacturing composition for molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a composition for molding which can obtain a molding material suitable for a thin molding by more finely fibrillating waste paper. <P>SOLUTION: The method for manufacturing the composition for molding comprises: a step of generating a primary pellet by pelletizing crushed waste paper in such a state that the paper is mixed with a thermoplastic resin; a step of generating a secondary pellet by further pelletizing the paper by comminuting the primary pellet by a comminutor; and a step of generating the molding material by mixing the secondary pellet with a resin material. Thus, since the cutting blade of the comminutor is sufficiently operated at waste paper fiber once crushed by charging the paper in the primary pellet state in the comminutor, the waste paper fiber can further finely be comminuted in the step simplified as compared with prior art. As compared with prior art, the flow of the resin is improved, the occurrence rate of the molding fault is reduced even in the thin molding, and its strength is improved. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for producing a molding composition obtained by kneading waste paper fibers made from waste paper and a thermoplastic resin.

[0002]

2. Description of the Related Art Conventionally, as a method for recycling and reusing used paper, used paper is crushed into a composite resin composition which is mixed with a thermoplastic resin. As a method for producing such a composite resin composition, for example, Japanese Patent Application Laid-Open No.
There is a method disclosed in 320367. This method
A resin material such as polypropylene is added to waste paper disentangled by a turbo mill or the like, heated, melted and kneaded, extruded from a nozzle to obtain resin pellets, and the resin pellets are injection-molded to obtain a molded article.

[0003]

However, in the above method, since the shredded waste paper is directly put into a turbo mill or the like for defibration, if the waste paper is defibrated to a certain extent,
The fibers floated in the mill, and the cutting edge of the mill hardly acted on the fibers, and it was difficult to make them finer with the same clearance of the mill. For this reason, in reality, waste paper is usually molded into various molded products in a state where it is not sufficiently defibrated, and although there was no problem with relatively thick molded products, molding with thin-walled molded products There is a problem in that the flow of the material becomes poor and molding defects may occur, or the strength of the molded product may be insufficient. Further, in order to finely disintegrate the waste paper in order to solve such a problem, it is necessary to perform the disentanglement process in which the clearance of the mill is packed in multiple stages, which requires extra equipment for that, However, there has been a problem that the manufacturing cost is significantly increased due to complication. In addition, setting the mill clearance too small can easily damage the cutting edge even if a small amount of foreign matter is caught, resulting in a significant reduction in the life of the device. There was a limit and I could not defibrate to the desired level.

Further, in the above method, since resin pellets are formed by heating, melting, and kneading and extruding from a nozzle, heating and friction in the step of kneading and extruding defibrated waste paper and resin may occur. , Burned paper easily causes physical property deterioration. When burnt paper is generated, there is a problem that the cellulose in the fiber is thermally decomposed to generate an odor and the molded product is colored.

The present invention has been made in view of the above circumstances, and provides a method and an apparatus for producing a molding composition capable of finely disintegrating waste paper to obtain a molding material suitable for a thin molded article. The second object is to provide a method and an apparatus for producing a molding composition capable of preventing deterioration of physical properties of waste paper due to heating.

[0006]

In order to achieve the above object, a method for producing a molding composition according to the present invention comprises a method in which crushed waste paper and a thermoplastic resin are mixed into pellets to form primary pellets. And a step of further crushing the waste paper by crushing the primary pellets with a fine pulverizer to produce secondary pellets by pelletizing, and mixing the secondary pellets with a resin material to form a molding material. The gist is to include the step of generating.

Further, the apparatus for producing a molding composition of the present invention comprises a pellet molding machine for pelletizing a crushed waste paper and a thermoplastic resin in a mixed state to produce primary pellets, and crushing the primary pellets. A fine crusher for further crushing waste paper by means of this, a pellet molding machine for pelletizing the waste paper crushed by the fine crusher to generate secondary pellets, and a molding material by mixing the secondary pellets with a resin material And a molding material generating means for generating the above.

As described above, in the method and apparatus for producing a molding composition of the present invention, the crushed waste paper and the thermoplastic resin are mixed into pellets to form primary pellets, and the primary pellets are finely pulverized. The waste paper is further crushed by crushing with a machine and then pelletized to produce secondary pellets. Therefore, when the used paper is put into the fine crusher in the form of primary pellets, the cutting blade of the fine crusher sufficiently acts on the once crushed waste paper fiber to further crush the used paper fiber. It becomes possible. Therefore, it is possible to finely disintegrate waste paper fibers at a low cost by a process that is simplified as compared with the related art. Then, the molded product molded with the molding composition thus obtained has a better resin flow than the conventional one, and the incidence of defective molding is reduced even in a thin product, and the strength of the molded product is reduced. Also improves. In addition, the clearance of the fine pulverizer can be set to be wide and it can be operated, and damage to the device due to foreign matter can be greatly reduced.

In the method for producing a molding composition of the present invention, the step of producing the molding material is performed by mixing the secondary pellets with the resin material and pulverizing with a fine pulverizer to mix the waste paper with the resin. If it is to be pelletized,
Alternatively, in the apparatus of the present invention, the molding material generating means, a fine pulverizer that mixes the secondary paper with the resin material to pulverize and mix the waste paper and the resin, and the waste paper crushed by the fine crusher, In the case of having a pellet molding machine for pelletizing a resin mixture, when producing a molding material, it is not necessary to perform heat-melt kneading and extrusion from a nozzle as in the conventional case, and thus defibration is performed. The heating, friction, etc. of the used paper can be significantly reduced, and the deterioration of physical properties due to burning of the used paper can be prevented. Therefore, it becomes possible to prevent odor and coloring of the molded product due to thermal decomposition of the fiber.

In the method and apparatus for producing a molding composition of the present invention, a fine pulverizer for pulverizing the primary pellets comprises
A casing formed in a cylindrical shape and provided with a fixed blade extending in the direction along the center line on the inner peripheral surface thereof, a rotary shaft coaxially provided on the center line of the casing, and attached to the rotary shaft. And a plurality of rotors each provided with a rotary blade extending in the direction along the center line, the clearance between the rotary blade and the fixed blade of each rotor, from the material inlet side to the outlet side. If it is set to become narrower in order, the gradually crushed primary pellets and waste paper fibers are sent from the rotor on the inlet side to the rotor on the outlet side, and the clearance gradually narrows. Therefore, it is possible to more efficiently and finely disintegrate.

In the method and apparatus for producing a molding composition of the present invention, a fine pulverizer for pulverizing the mixture of the secondary pellets and the resin material is formed in a cylindrical shape and has an inner peripheral surface along the center line. A casing provided with a fixed blade extending in a direction, a rotary shaft coaxially provided on the center line of the casing, and rotary blades attached to the rotary shaft and extending in a direction along the center line, respectively. And a plurality of rotors, and the clearance between the rotary blade and the fixed blade of each rotor is set to become gradually narrower from the material inlet side to the material outlet side, gradually, The secondary pellets are crushed by the external force such as the shearing action of the rotary blades and fixed blades of multiple rotors, which narrows the clearance. Is, resin powder which has been pulverized and waste paper fibers are mixed uniformly.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described in detail.

The method for producing the molding composition of the present invention is shown in FIG.
As shown in FIG. 4, coarse crushing A and medium crushing B, which are steps of crushing waste paper, primary pellet generating step C, primary pellet crushing / defibrating step D, secondary pellet generating step E, and mixing of resin materials. Each step of a crushing step F, a forming step G of molding pellets, and a forming step H of a molded product is provided.

Then, each of the steps A, B, C, D, E,
In F, G, H, coarse crusher 1, medium crusher 2, respectively
Pellet molding machine 20, fine pulverizer 31, pellet molding machine 2
0, a fine pulverizer 31, a pellet molding machine 20, and an injection molding machine are used, and these apparatuses constitute the apparatus for producing the molding composition of the present invention.

In the method for producing a molding composition of the present invention, first, coarse crushing A and medium crushing B, which are the steps of crushing used paper into fine pieces, are performed.

The used paper is not particularly limited, and various kinds of used paper can be used. For example, OA
Examples include related waste paper, cardboard, newspapers, magazines, Thomson-processed debris, bags of resin raw material pellets, used passenger tickets, betting tickets, and other magnetic powder.

Further, in the present invention, as the used paper, a paper material in which a thermoplastic resin material is impregnated and / or laminated can be effectively applied. For example, punch packs of milk packs, various packaging box papers, packaging bag papers, etc. can be mentioned.

By the coarse crushing A and the medium crushing B, the used paper has an average thickness of 0.01 to 0.1 mm and an average length of 2.5 mm.
It is crushed until it becomes the following fibrous form.

As the crushing apparatus used for the coarse crushing A and the medium crushing B in the crushing step of the used paper, for example, as shown in FIG. 2, a crushing machine 1 for crushing the used paper and a crushed machine are used. A machine equipped with a medium crusher 2 for medium crushing used paper is preferably used.

In the above-mentioned crushing apparatus, a sheet of waste paper is put into the hopper 4 above the coarse crusher 1, and the waste paper coarsely crushed by the coarse crusher 1 is fed through the pressure blower 3 and the pressure feed pipe 5. It is sent to the crusher 2, and the medium crusher 2 performs intermediate crushing.

The above-mentioned crushing device includes a medium crusher 2 for the pressure feed pipe 5.
The portion immediately before and the intermediate crusher 2 are provided with additive introduction ports 6 and 7 for introducing the additives, and at least one of an antioxidant and a neutralizing agent as an additive at the stage of intermediate pulverization or at least immediately before that. Either is added. In this way, by adding an antioxidant and a neutralizing agent when crushing used paper, even if the used paper is heated by frictional heat during crushing, the antioxidant suppresses the generation of aldehydes. Then, the aldehydes generated by the neutralizing agent are neutralized. Therefore, the odor and coloring generated in the molded product and the like are significantly reduced.

The antioxidant is not particularly limited, and various kinds of antioxidants can be used. For example, in addition to phenol-based and aromatic amine-based compounds, sulfur-based, phosphorus-based, organometallic compounds and the like can be mentioned. These can be used alone or in combination.

Of these, phenolic antioxidants and phosphorus antioxidants can be preferably used. Examples of the phenol type include hydroquinone monobenzyl ether, 2.6-di-tert-butylphenol,
2.6-di-tert-butyl-P-cresol, 2.
4.6-tri-tert-butylphenol, 4.4 '
-Bis (3.5-di-tert-butylphenol),
Examples thereof include bis (4-oxy-2.6-di-tert-butylphenyl) methane, various alkylated phenols, cresols and styrenated phenols. Examples of phosphorus-based phosphites include aryl or alkylaryl phosphites such as triphenylphosphite and nonylphenylphosphite.

As the above-mentioned antioxidant, the radical chain inhibitor and the peroxide decomposing agent are used because they effectively prevent the oxidation of the resin material by preventing the radical chain or decomposing the peroxide. Those containing at least one of the above are preferably used. For example, examples of the radical chain inhibitor include Adeka Busta A30 (trade name) manufactured by Asahi Denka Kogyo Co., Ltd., and examples of the peroxide decomposer include Adeka Busta PEP2 (trade name) manufactured by Asahi Denka Kogyo Co., Ltd. .

Further, the above-mentioned neutralizing agent can effectively neutralize aldehydes generated by the thermal decomposition of cellulose, and can effectively prevent the odor and coloring of the molded article.
Those that neutralize aldehydes are preferably used. For example, a cyclic active imino compound is effective, and examples thereof include hydantoins such as 5.5 dimethylhydantoin and imidazole compounds.

The amount of the above additive added is preferably 0.005% by weight or more and 1% by weight or less, more preferably 0.01% by weight or more and 0.5% by weight, based on the mixture of waste paper and thermoplastic resin. % Or less, more preferably 0.
It is from 05% by weight to 0.1% by weight. This is because the above-mentioned addition amount can effectively prevent the oxidation of the resin material and the odor and coloration of the molded product.

In this example, as shown in FIG. 3, the coarse crusher 1 has a rotary blade 9 whose axis extends substantially vertically (the figure is a view from above), and Rotary blade 9
A vertical crusher for roughly crushing used paper with a fixed blade 10 provided around the is used. The fixed blade 10 and the rotary blade 9 are surrounded by a mesh drum 11, and the coarsely crushed waste paper passes through the mesh holes of the mesh drum 11 and is fed to the pressure feed pipe 5.

As the coarse crusher 1, a vertical type crusher for roughly crushing used paper with a rotary blade 9 having a vertically extending axial center and a fixed blade 10 is used. Even if clogged, it is easy to remove.

In this example, as shown in FIG. 4, the intermediate crusher 2 has a fixed disk 13 in which fixed pins 15 are arranged in a row on a concentric circle P on one side of the disk, and the fixed disk 13 of the disk. A pin mill having a rotating disk 14 on one surface of which rotating pins 16 are arranged so as to be arranged on a concentric circle Q located between the concentric circles P is used. Then, as shown in FIG. 5, the fixed disk 13 and the rotary disk 14 are opposed to each other, and the fixed pin 15
And the rotary pin 16 are engaged with each other.

In this state, the rotating disk 14 is rotated about the center of the disk to rub and crush the waste paper between the fixed pin 15 and the rotating pin 16. In FIG. 5, 18 is a case and 17 is a mesh drum. In this way, since the waste paper is rubbed and crushed between the fixed pin 15 and the rotary pin 16, the waste paper is loosened between the fixed pin 15 and the rotary pin 16, so that the fiber is cut less and is sufficiently unwound. Be refined.

The apparatus used in the crushing step of the used paper is not limited to the above-mentioned one, but a combination of a high-speed shredder and a jet mill, an open cotton pulp crusher for paper diapers, a turbo cutter, etc. Various types can be used.

Next, a primary pellet producing step C is carried out in which the crushed fibrous waste paper is kneaded and granulated to form primary pellets.

FIG. 6 shows an example of a pellet molding machine 20 used in the primary pellet forming step C. This pellet molding machine 20 inputs crushed waste paper from a hopper 21,
The mixture is kneaded and granulated to form pellets, and the discharge port 22
The primary pellets are discharged from.

At the time of this granulation, it is preferable to add the same antioxidant and neutralizing agent as those mentioned above. By doing so, even if the waste paper is heated by heating during friction or frictional heat, the generation of aldehydes is suppressed by the antioxidant, and the aldehydes generated by the neutralizing agent are neutralized. . Therefore, the odor and coloring generated in the molded product and the like are significantly reduced.

The above-mentioned granulation is preferably carried out in a state where waste paper and thermoplastic resin are mixed. If the used paper is a paper material impregnated and / or laminated with a thermoplastic resin material, it can be used as it is. If the used paper does not contain a resin component, the crushed used paper is mixed with 2 to 10% by weight of an olefin resin such as a polyolefin elastomer.

By doing so, the crushed waste paper and the thermoplastic resin are granulated to form primary pellets, so that the bulk of the fibrous waste paper is about 1/10 to 1/30. Decrease. Therefore, the speed of supplying the used paper to the apparatus is increased, and the productivity is extremely improved. Also,
Since it is in the form of pellets, it does not take up space when storing crushed waste paper, and handling such as transportation is easy. Further, the accuracy of the weight measurement is improved, so that the mixing ratio with the thermoplastic resin is stable and the quality is improved. Moreover, in the above-mentioned primary pellets, since the thermoplastic resin that is easily mixed with various resins is coated around the fibers, the compatibility between the fibers and the resin material is significantly improved, and the recycled resin with a large proportion of various resins is mixed. Even in such cases, the strength of the molded product is secured.

Examples of the above-mentioned polyolefin elastomer include high-density polyethylene, low-density polyethylene, polypropylene, polybutene, poly-4-methylpentene-
1, oligomers such as a copolymer of ethylene and α-olefin, a copolymer of propylene and α-olefin, and an elastomer such as ethylene octene copolymer (trade name “Engage”: Dow Chemical Co.). These may be used alone or in combination.

The mixing ratio of the above polyolefin elastomer to used paper is preferably 2 to 10% by weight. 2%
If it is less than 10%, the effect of reducing the bulk or improving the compatibility with the resin is poor, and if it exceeds 10%, the productivity is improved, but the strength of the molded product is rather reduced when mixed with a resin other than olefin. Because it does.

As described above, when the used paper is a paper material impregnated and / or laminated with a thermoplastic resin material, the same effect can be obtained without adding an olefin resin. However, it is also possible to granulate by adding an olefin resin.

As shown in FIG. 7, the pellet molding machine 20 has a rotary drum 23 having a large number of pellet extrusion holes 24 on its peripheral surface, and an outer peripheral surface of the rotary drum 23 which is the same as the inner peripheral surface of the rotary drum 23. It is provided with a first roll 25 and a second roll 26 which are rotatably supported while maintaining a clearance.

The crushed waste paper and the thermoplastic resin charged in the rotary drum 23 are sandwiched between the outer peripheral surfaces of the first and second rolls 25 and 26 and the inner peripheral surface of the rotary drum 23. Are compressed and extruded from the pellet extruding hole 24 to be efficiently granulated. In FIG. 7, 27 is a cutter for cutting the mixture of waste paper fiber and resin extruded from the pellet extruding hole 24.

As shown in FIG. 8, the first roll 25 has a groove 28 formed on the outer peripheral surface thereof and extending in a direction orthogonal to the rotation direction of the rotary drum 23. Therefore, the groove 2
The frictional heat generated between the outer peripheral surface of the first roll 25 and the inner peripheral surface of the rotating drum 23 by 8 melts the thermoplastic resin, and the crushed waste paper and the thermoplastic resin are effectively granulated. Pelletized.

As shown in FIG. 9, the second roll 26 has a large number of recesses 29 on its outer peripheral surface. For this reason, the crushed waste paper and the thermoplastic resin are pushed between the outer peripheral surface of the second roll 26 and the inner peripheral surface of the rotary drum 23 by the recess 29, and are effectively granulated and pelletized. It

By kneading and granulating in this manner, primary pellets of about 2 to 6 mm can be obtained. Here, the kneading temperature is preferably 80 to 110 ° C. If the temperature is lower than 80 ° C, the load on the kneading machine during kneading becomes too large, and 1
If the temperature exceeds 10 ° C., the polyolefin elastomer and the thermoplastic resin will be completely melted, and the kneading with the waste paper will be worse.

The kneading at the time of granulation is not limited to the pellet molding machine 20 described above, and the kneading is carried out by a Henschel mixer and kneading by an extruder, or by a kneader ruder or a high kneading type twin-screw extruder. Can be dispersed, or another method can be used.

Next, the above primary pellets are pulverized by a pulverizer 31.
The crushing and defibrating step D of the primary pellets for further defibrating the crushed waste paper is performed by crushing.

For example, as shown in FIG. 10, the fine pulverizer 31 has a cylindrical casing 32 and a rotary shaft 33 coaxially provided on the center line RR of the casing 32.
And a plurality of (four in this example) first to fourth rotors 34A, 34B, 34C, 3 attached to the rotary shaft 33.
4D and.

The rotating shaft 33 is supported by bearings 35 on both side walls of the casing 32, and a belt (not shown) is wound around a pulley 36 fixed to the end of the rotating shaft 33 so that the center line R-R can be rotated. It is designed to rotate at high speed as a heart.

The inner peripheral surface of the casing 32 is shown in FIG.
As shown in, a fixed blade 37, which is a large number of protrusions extending in the direction along the center line RR, is provided. on the other hand,
The first to fourth rotors 34A, 34B, 34C, 34D
Each of them is provided with a rotary blade 38 which is a large number of ridges or blades extending in the direction along the center line RR. A predetermined clearance t is provided between the fixed blade 37 and the rotary blade 38.

The casing 32 is provided at one end thereof with an inlet 39 into which primary pellets, which are works, are introduced. At the other end of the casing 32, the crushed and disentangled primary pellets are discharged. A discharge port 40 is provided.

A plurality of first to fourth rotors 34A, 34B, 34C, 34 arranged in order from the side close to the input port 39.
In D, the clearances t are set to be different from each other, and the clearance t is set to be gradually narrowed from the side close to the input port 39 to the discharge port 40 side. For example, the clearance t is set to 5 mm in the first rotor 34A closest to the input port 39, 4 mm in the next second rotor 34B, 2 mm in the next third rotor 34C, and the first rotor 34A closest to the outlet 40. 4 rotor 34
In D, it is set to 1.5 mm.

In the fine pulverizer 31, the primary pellets are supplied together with a large amount of air from the charging port 39, and the supplied primary pellets are the first to fourth rotors 34A, 34B, 34.
C, 34D rotary blade 38 and fixed blade 37 of casing 32
While being finely pulverized, the used paper fibers, which are the main component of the primary pellets, are further finely defibrated. Then, the crushed and defibrated waste paper fibers are discharged from the discharge port 40 together with the air.

At this time, the waste paper fibers are not fed to the fine pulverizer 31 in the crushed state but are once formed into primary pellets, and the pellets are fed. Rotors 34A, 34B, 34C, 34
It is possible to further finely disintegrate the finely crushed waste paper fibers by receiving an external force such as a shearing action by the rotary blade 38 of D and the fixed blade 37 of the casing 32.

Then, the crushed primary pellets and waste paper fibers are sent from the first rotor 34A near the inlet 39 toward the rotor 34D on the outlet 40 side, and the clearance is gradually narrowed. It is possible to more efficiently and finely disintegrate. For example, with the above-described clearance setting, it is possible to defibrate the fiber length to about 0.3 mm or less.

Next, the used pellet fibers finely defibrated by the fine pulverizer 31 are pelletized by the pellet molding machine 20 described with reference to FIGS. 6 to 9 to produce secondary pellets. Do.

The secondary pellet producing step E can be basically performed in the same manner as the primary pellet producing step C described above, and the pellet molding machine 20 can also be used as the same machine. Also, in the secondary pellet forming step E, a thermoplastic resin such as a polyolefin resin can be additionally added. Further, in this step, the same antioxidant and neutralizing agent as those described above can be added.

Next, a thermoplastic resin pellet, which is a molding material, is mixed with the secondary pellets, and a resin material mixing / pulverizing step F for pulverizing the mixed resin pellets and secondary pellets (waste paper pellets) is carried out. To do.

In the mixing / pulverizing step F, the fine pulverizer 31 described with reference to FIGS. 10 and 11 is used. This mixture
The crushing step F can be basically performed in the same manner as the above-described primary pellet crushing / defibrating step D, and the fine crusher 31 can also serve as the same machine.

As the thermoplastic resin mixed here,
For example, polypropylene, ABS resin, styrene resin, polyethylene resin, polyacetal, polycarbonate, or the like that is easily mixed with the polyolefin elastomer is used.

The mixing ratio of the thermoplastic resin pellets is such that the resin content of the final molding composition is 20-80 by weight.
% Is preferable, and 30% to 70% is more preferable. When the resin content of the molding composition is 20% or less, the ratio of the fibers is too large and the strength of the molded product is reduced, and when it exceeds 80%, the amount of heat generated when the molded product is burned increases, This is because disposal becomes difficult. Also,
A recycled resin obtained by crushing a film, a sheet meal, a defective molded product, or the like made of the above resin material with a crusher to about 2 to 6 mm is also suitably used.

According to the process F using the fine crusher 31, the plurality of first to fourth clearances t in which the clearance t is gradually narrowed.
Rotating blade 38 of each rotor 34A, 34B, 34C, 34D
The secondary pellets, which are used paper pellets, are crushed by the external force such as the shearing action of the fixed blade 37 of the casing 32 and the used paper fibers are further finely crushed, and the resin pellets are also finely crushed and crushed with the used paper fibers. Resin powder is mixed evenly.

Next, a molding pellet forming step G is carried out in which the defibrated mixture of waste paper fibers and resin powder is pelletized by the pellet molding machine 20 described with reference to FIGS. 6 to 9 to form molding pellets. To do.

This molding pellet forming step G can be basically carried out in the same manner as the above-mentioned primary pellet forming step C and secondary pellet forming step E, and the pellet forming machine 20 also serves as the same machine. You can In this way, it becomes possible to generate molding pellets without performing conventional extrusion molding, and it is not necessary to perform conventional heat-melt kneading or extrusion from a nozzle when generating a molding material. In addition, the heating and friction of the defibrated waste paper can be significantly reduced, and the deterioration of physical properties due to burning of the waste paper can be prevented. Therefore, it becomes possible to prevent odor and coloring of the molded product due to thermal decomposition of the fiber.

Then, the molding pellets formed in the above step G are subjected to an injection molding machine to obtain a molded product having a desired shape. At this time, in order to remove water adsorbed on the fibers before molding, it is preferable to dry at about 80 to 100 ° C. for about 3 to 4 hours with a hopper dryer or a box dryer. The molding temperature is preferably set to a relatively low temperature in order to prevent carbonization of the fibers. Other than that, it can be molded in the same manner as molding of a normal resin material.

The molded product thus obtained has a good flow of the molding material, a reduced incidence of molding defects such as wrinkles, and a good mechanical strength. In addition, the amount of heat generated when burned is small, and incineration treatment similar to general combustible materials is possible. In addition, burnt charcoal of burned paper and generation of aldehydes are effectively suppressed, and problems such as coloring and odor hardly occur.

As described above, according to the above-described method and apparatus for producing a molding composition, the waste paper in the form of primary pellets is put into the fine crusher to finely crush the once crushed waste paper fibers. The cutting edge of the machine works sufficiently to allow the used paper fibers to be further finely crushed. Therefore,
The waste fiber can be finely disintegrated at low cost by a simplified process compared to the conventional method. Then, the molded product molded with the molding composition thus obtained has a better resin flow than the conventional one, and the incidence of defective molding is reduced even in a thin product, and the strength of the molded product is reduced. Also improves. In addition, the clearance of the fine crusher can be set to be wider than that of the conventional one, and the fine crusher can be operated, and damage to the device due to foreign matter can be significantly reduced.

Instead of steps F and G, step E
Secondary pellets that are waste paper pellets produced through
The thermoplastic resin pellets may be mixed, heated and kneaded by an extruder, and then granulated and pelletized to produce a molding composition. The temperature of the heat kneading at this time is preferably 100 to 150 ° C.
This is because if the temperature is lower than 100 ° C., it takes time to knead, and if the temperature exceeds 150 ° C., the waste paper may be burnt and burnt. Granulation may burn the fibers due to the heat retention of the waste paper,
Preference is given to underwater extrusion.

In this case also, since the waste paper fibers are further finely crushed by introducing the waste paper into the primary pellets in the state of primary pellets, a molded article molded with the obtained molding composition is obtained. As compared with the conventional one, the flow of resin is improved, the incidence of defective molding is reduced even in a thin product, and the strength of the molded product is improved.

[0069]

INDUSTRIAL APPLICABILITY As described above, according to the method and apparatus for producing a molding composition of the present invention, waste paper fibers once crushed by throwing them into a fine pulverizer in a state of primary pellets On the other hand, the cutting edge of the fine crusher sufficiently acts, and the waste paper fibers can be further finely crushed. Therefore, it is possible to finely disintegrate waste paper fibers at a low cost by a process that is simplified as compared with the related art. Then, the molded product molded with the molding composition thus obtained has a better resin flow than the conventional one, and the incidence of defective molding is reduced even in a thin product, and the strength of the molded product is reduced. Also improves. In addition, the clearance of the fine pulverizer can be set to be wide and it can be operated, and damage to the device due to foreign matter can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a process explanatory view showing an embodiment of a method for producing a molding composition of the present invention.

FIG. 2 is an explanatory diagram showing a crushing device used in an embodiment of a device for producing a molding composition of the present invention.

FIG. 3 is an explanatory view showing a coarse crusher.

FIG. 4 is a diagram showing a disk of a medium crusher, where (a) is a fixed disk and (b) is a rotating disk.

FIG. 5 is a cross-sectional view showing the structure of a medium crusher.

FIG. 6 is a side view showing a pellet molding machine.

FIG. 7 is an explanatory diagram showing an internal structure of a pellet molding machine.

FIG. 8 is a view showing a first roll, (a) is a side view,
(B) is a front view.

FIG. 9 is a view showing a second roll, (a) is a side view,
(B) is a front view.

FIG. 10 is a cross-sectional view showing a fine pulverizer.

FIG. 11 is an enlarged side view of a main part of the fine pulverizer.

[Explanation of symbols]

A Process of crushing used paper (coarse crushing) B Process of crushing used paper (medium crushing) C Primary pellet production process D Crushing and defibration process of primary pellets E Secondary pellet production process F Resin material mixing / grinding process G Molding pellet production process H molding process P concentric circles Q concentric circles 1 coarse crusher 2 Medium crusher 3 pressure blower 4 hoppers 5 pressure pipe 6 Additive input port 7 Additive input port 9 rotary blades 10 fixed blade 11 mesh drum 13 fixed disk 14 rotating disk 15 fixing pin 16 rotating pins 17 mesh drum 18 cases 20 Pellet molding machine 21 hopper 22 Outlet 23 rotating drum 24 pellet extrusion hole 25 First Roll 26 Second Roll 27 cutter 28 groove 29 recess 31 fine crusher 32 casing 33 rotation axis 34A 1st rotor 34B 2nd rotor 34C 3rd rotor 34D 4th rotor 35 bearings 36 pulley 37 fixed blade 38 rotary blades 39 input port 40 outlet

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B09B 3/00 301 B09B 3/00 301Z B29B 9/00 B29B 9/00 11/10 11/10 B09B 3 / 00 ZF term (reference) 4D004 AA12 AC04 BA10 CA04 CA14 CA45 CB13 CB16 CC15 CC17 4D065 CA16 CB01 CC01 DD06 DD18 EB12 EB14 EC07 4F201 AC01 AD06 BA01 BA02 BA03 BC15 BC17 BC19 BC29 BD04 BK13 BK14 BL09 BL36 BL43 BN29

Claims (6)

[Claims] 1. A step of pelletizing a crushed waste paper and a thermoplastic resin in a mixed state to produce a primary pellet, and further crushing the waste paper by crushing the primary pellet with a fine crusher and then pelletizing the pellet. And a step of mixing the secondary pellets with a resin material to produce a molding material, the method for producing a molding composition. 2. The step of producing the molding material is a step of mixing secondary pellets with a resin material and pulverizing with a fine pulverizer to mix the waste paper with the resin and then pelletizing. 1. A method for producing the molding composition of. 3. A pellet forming machine for pelletizing a crushed waste paper and a thermoplastic resin to produce primary pellets, and a fine crusher for further crushing the waste paper by crushing the primary pellets. A pellet molding machine for pelletizing waste paper pulverized by the fine pulverizer to produce secondary pellets, and a molding material producing means for producing a molding material by mixing the secondary pellets with a resin material An apparatus for producing a molding composition, comprising: 4. The molding material generating means mixes secondary pellets with a resin material and pulverizes the fine pulverizer to mix the waste paper and the resin, and the mixture of the waste paper and the resin pulverized by the fine crusher. 4. The apparatus for producing a molding composition according to claim 3, further comprising a pellet molding machine for pelletizing. 5. A fine crusher for crushing the primary pellets, wherein the finely crusher is formed in a cylindrical shape, a casing provided with a fixed blade extending in a direction along a center line on an inner peripheral surface thereof, and a casing on the center line of the casing. A rotary shaft provided coaxially, and a plurality of rotors each provided with a rotary blade attached to the rotary shaft and extending in a direction along the center line,
The method for producing a molding composition according to claim 1 or 3, wherein the clearance between the rotary blade and the fixed blade of each rotor is set to become gradually narrower from the material inlet side to the material outlet side. Or device. 6. A casing in which a fine pulverizer for pulverizing the mixture of the secondary pellets and the resin material is formed in a cylindrical shape and provided with a fixed blade extending in a direction along a center line on an inner peripheral surface thereof. The casing includes a rotating shaft coaxially provided on the centerline of the casing, and a plurality of rotors attached to the rotating shaft and provided with rotating blades each extending in a direction along the centerline. The molding according to any one of claims 2, 4 and 5, wherein the clearance between the rotary blade and the fixed blade of the child is set to become gradually narrower from the material inlet side to the material outlet side. Method or apparatus for producing a composition for use.