KR100856943B1 - Pellet, manufacturing method thereof and molded object thereof - Google Patents

Abstract

An object of this invention is to provide the pellet which can prevent the dispersion | distribution defect of the raw material in the inside of an extruder, and can make a molded article continuously for a long time using an extruder, and its manufacturing method.

A pellet 1A constituting a raw material of a molded article produced by molding processing, wherein the pellet 1A is a mixture of fine powder of hydrophilic polymer, fine powder of polyolefin thermoplastic synthetic resin, fine powder of plant fiber and fine powder of inorganic compound. In this case, a predetermined amount of water is contained, the particle diameter of these fine powders is in the range of 30 to 200 µm, the water content of the pellet 1A is in the range of 5 to 30% with respect to the total weight of the pellet 1A, Pellets in which these fine powders are substantially uniformly dispersed in 1 A of pellets, its manufacturing method, and its molded article.

Description

Pellet, Method for Manufacturing the Same, and Molded Article thereof {PELLET, MANUFACTURING METHOD THEREOF AND MOLDED OBJECT THEREOF}

1 is a perspective view of a pellet shown as an example.

FIG. 2 is a process schematic diagram showing an example of the method for producing the pellet of FIG. 1. FIG.

3 is a process schematic diagram illustrating a method for producing a foamed material made from the pellets of FIG. 1.

4 is a perspective view of a pellet shown as another example.

FIG. 5 is a process schematic diagram showing an example of the method for producing the pellet of FIG. 4. FIG.

FIG. 6 is a process schematic diagram illustrating a method for producing a foamed material made from the pellets of FIG. 4.

(Explanation of symbols for the main parts of the drawing)

1A. Pellet 1B... Pellet

2 … Hydrophilic polymer 3... Polyolefin Synthetic Resin

4 … Plant fiber 5... Inorganic compounds

6. Flowable mixture 7. Foam material (molded product)

11. Kneader 12. Granulator

15... Extruder L1... Length                 

L2... diameter

P1... Fine powder of the hydrophilic polymer (first fine powder)

P2... Fine powders of polyolefin-based synthetic resins (second fine powder)

P3... Fine powder of plant fiber (second fine powder)

P4... Fine powder of inorganic compound (second fine powder)

S1... Mixture production process S2.. Pellet Manufacturing Process

W… water

The present invention relates to pellets constituting a raw material of a molded article produced by molding processing, a method for producing the same, and a molded article thereof, and more particularly, to prevent a dispersion of raw materials in the extruder when the molded article is manufactured by an extruder. The present invention relates to pellets, a method for producing the same, and a molded product thereof, which can continuously form a molded article for a long time using an extruder.

Conventionally, as a foaming material, for example, in the prior art document, a paper component, a thermoplastic synthetic resin, a vegetable material, and water are kneaded while heating in the inside of an extruder, and the paper component, a synthetic resin, and a vegetable are made using vaporization of water in the inside of the extruder. A foam material obtained by foaming a mixture made of a material at a predetermined magnification and a method of manufacturing the same are disclosed (see Patent Document 1).                         

This foam member uses shredded material of old paper as a paper component, a powdered polypropylene homopolymer as a synthetic resin, and corn starch as a vegetable material. This foam contains crushed products and cornstarch from old paper, which is useful for the effective use of resources, and can reduce the burning calories during incineration of the foam compared to the case where the foam is made of only synthetic resin. .

However, in the foam of this kind, the specific gravity or volume of the shredded material, the powdered polypropylene homopolymer, and the corn starch are different so that they are not uniformly dispersed in the extruder during the production of the foamed material. And corn starch may be omnipresent. If the crushed material and corn starch are unevenly distributed in a part of the foam material, there is a problem that the strength of the foam material in the part is significantly reduced.

In addition, in the production of foam of this kind, the crushed material concentrates on the screw of the extruder due to the dispersion of crushed material in the inside of the extruder, the crushed material is entangled in the screw, or the engagement of the screw with the mixture becomes unstable. Due to this, pulsation occurs in the rotation of the screw, and the mixture may cause excessive foaming or poor foaming. In addition, in the production of this kind of foaming material, it is difficult to continuously manufacture the foaming material for a long time because the crushed material may concentrate on a part of the die due to the dispersion of the crushed material in the inside of the extruder, and the die may be clogged. There is.                         

[Patent Document 1] Japanese Patent Laid-Open No. 2000-273800

SUMMARY OF THE INVENTION An object of the present invention is to provide a pellet capable of preventing dispersion of raw materials in the inside of an extruder when producing a molded article with an extruder, and a pellet and a method for producing the same, and a molded article thereof, which can continuously make a molded article using an extruder for a long time. It is in doing it.

The form of this invention for solving the said subject is a pellet which comprises the raw material of the molded article produced by molding process.

The pellet of the present invention comprises a mixture of a first fine powder formed of a hydrophilic polymer, a polyolefin-based thermoplastic synthetic resin, and a second fine powder formed of at least one of plant fibers and an inorganic compound, and contains a predetermined amount of water. The particle diameter of the first and second fine powders is in the range of 30 to 200 μm, the water content of the pellets is in the range of 5 to 30% of the total weight of the pellets, and the first and second fine powders are in the pellets. It is characterized in that it is dispersed approximately uniformly.

As an example of embodiment of the present invention, the weight ratio of the hydrophilic polymer to the total weight of the pellet is 5 to 67.5%, the weight ratio of the synthetic resin to the total weight of the pellet is 10 to 50%, and the total weight of the pellet. It is preferable that the weight ratio of the plant fiber is 20 to 60%, and the weight ratio of the inorganic compound to the total weight of the pellet is in the range of 0.5 to 35%.

As another example of embodiment of this invention, it is preferable that the said pellet is melt | dissolved at the temperature of 150-190 degreeC, while disintegrating at the pressure of 100-490N.

As another example of embodiment of this invention, the specific gravity of the said pellet exists in the range of 0.2-1.0.

As another example of embodiment of this invention, it is preferable that the said pellet shows a substantially cylindrical shape, the length of the said pellet is 0.5-10.0mm, and the diameter of the said pellet exists in the range of 1.0-5.0mm.

Moreover, another aspect of this invention for solving the said subject is the manufacturing method of the pellet which comprises the raw material of the molded article produced by molding process.

In the method of the present invention, water is added to a first fine powder formed of a hydrophilic polymer, a second fine powder formed of at least one of a polyolefin-based thermoplastic synthetic resin, a plant fiber and an inorganic compound, and the first and second fine powders are A mixture manufacturing step of kneading with water to produce a fluid mixture, and a pellet manufacturing step of wet granulating the fluid mixture, followed by drying to produce the pellets, wherein the particle diameters of the first and second fine powders The range of 30-200 micrometers, and the ratio of the said water added in the said mixture manufacturing process are 20 to 50% with respect to the total weight of the said 1st and 2nd fine powder kneaded in the said mixture manufacturing process, It is characterized by the above-mentioned. It is.

In addition, the present invention is characterized in that the pellets produced by the above method are used, the pellets are foamed, molded into a predetermined shape and formed into a molded article.

Next, the pellet which concerns on this invention, its manufacturing method, and its molded article are demonstrated in detail with reference to attached drawing.                     

1 is a perspective view of a pellet 1A shown as an example. This pellet 1A constitutes a raw material of the foamed material 7 (molded product) produced using the technique of extrusion molding (see Fig. 3).

The pellet 1A is made of fine powder (P1) (first fine powder) formed of the hydrophilic polymer (2), fine powder formed of polyolefin-based thermoplastic synthetic resin (3), plant fiber (4), and inorganic compound (5). P2, P3, P4) (2nd fine powder) is a mixture which mixed in predetermined ratio (refer FIG. 2). The pellet 1A contains a predetermined amount of water.

The pellet (1A) contains fine powder (P1) of the hydrophilic polymer (2), fine powder (P2) of the synthetic resin (3), fine powder (P3) of the plant fibers (4), and fine powder (P4) of the inorganic compound (5). ) Are distributed approximately uniformly. The particle diameter of these fine powders P1, P2, P3, P4 exists in the range of 30-200 micrometers. In the pellet 1A, these fine powders P1, P2, P3, and P4 cannot be seen substantially.

The pellet 1A is a solid having a cylindrical shape, its length L1 is in the range of 0.5 to 10.0 mm, and its diameter L2 is in the range of 1.0 to 5.0 mm. The pellet 1A has a volume specific gravity in the range of 0.2 to 1.0, disintegrates at a pressure of 100 to 490 N, and dissolves at a temperature of 150 to 190 ° C.

At least one of plant-based natural polymers and synthetic polymers is used for the hydrophilic polymer 2. The hydrophilic polymer (2) functions as a binder for bonding the synthetic resin (3), the plant fibers (4), and the inorganic compound (5).

Starch may be used in plant-based natural polymers. The starch may be one or more of potato, sweet potato, corn starch, rice starch, wheat starch, konjac, tapioca, modified starch, and processed starch. In addition to starch, plant-based natural polymers may use one or more of glue, radish, bran, rice bran, bean curd, gelatin.                     

As the synthetic polymer, one or more of polyvinyl alcohol, acrylate, maleate and oil wax can be used. The fine powder (P1) of the hydrophilic polymer (2) may be made by finely pulverizing plant-based natural polymer and synthetic molecules with a grinder.

As the polyolefin-based thermoplastic synthetic resin 3, any one of polypropylene and polyethylene, or a resin in which a predetermined ratio thereof is mixed is used.

As the polypropylene, one or more of block polymerized polypropylene, random polymerized polypropylene, homo polymer polypropylene, metallocene catalyst polypropylene, and modified polypropylene can be used.

As the polyethylene, one or more of low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, metallocene catalyst polyethylene, and modified polyethylene can be used.

As the fine powder P2 of the synthetic resin 3, polymer particles produced during the polymerization of the synthetic resin 3 can be used. In addition, the fine powder P2 of the synthetic resin 3 may be made by finely pulverizing the lump-shaped synthetic resin 3 with a grinder.

Paper is used for the plant fiber 4. The paper can be new or old. Paper can also be used gripping paper or hand paper produced when producing this. It is preferable to use a paper free of chlorine and a fluorescent brightener. It is preferable that the plant fiber 4 made from old paper is 95% or more of cellulose components. The fine powder P3 of the plant fiber 4 formed of paper can be made by finely pulverizing paper with a grinder.                     

The plant fiber 4 may be made of pulp before it is made of paper. The fine powder P3 of the plant fiber 4 formed of pulp can be made by finely grinding the pulp with a grinder. The fine powder P3 of the plant fiber 4 made of pulp is preferably one having a lignin content of 1% or less.

The pulp may be one or more of mechanical pulp, chemical mechanical pulp, semichemical pulp, and chemical pulp. The pulp is preferably wood pulp, but wood pulp may be mixed with one or more of old pulp, stem pulp, bast pulp and the like. It is preferable to use a pulp containing no chlorine and a fluorescent brightener.

In addition to paper or pulp, the plant itself may be used for the plant fibers 4. The fine powder P3 of the plant fiber 4 formed of a plant may be made by finely pulverizing the plant with a mill. Plants may use at least one of Pagas, Kenaf (Mdaceae), reed, hemp, cedar, mulberry, canby or bamboo.

The inorganic compound (5) is one or more of titanium oxide, talc, calcium carbonate, clay, magnesium sulfate, calcium sulfate, barium sulfate, kaolin, aluminum hydroxide, magnesium hydroxide, galvanized, shell calcium, and coal. have. The fine powder P4 of the inorganic compound 5 can be made by finely pulverizing the inorganic compound 5 as long as it is a lump.

FIG. 2 is a process schematic diagram showing the method for producing the pellet 1A of FIG. 1. The method for producing the pellet 1A is a mixture production process S1 for producing the fluid mixture 6 using the kneader 11, and pellet 1A from the mixture 6 using the granulator 12. It is formed by the pellet manufacturing process (S2).                     

In the mixture preparation step (S1), fine powders (P1, P2, P3, P4) of the hydrophilic polymer (2), the polyolefin-based thermoplastic synthetic resin (3), the plant fiber (4), and the inorganic compound (5) (first and second) The fine powder) is introduced into the kneader 11 and water W is injected into the kneader 11. In the kneader 11, these fine powders P1, P2, P3, P4 are kneaded together with water W by the rotation of the screw (not shown) installed therein, and the viscous fluid mixture 6 ) Is manufactured.

The ratio of the water (W) injected into the kneader 11 (weight ratio of water applied in the mixture manufacturing process) is the total weight of the fine powders (P1, P2, P3, P4) injected into the kneader 11 (mixture production). The total weight of the first and second fine powders to be kneaded in the process), in the range of 20 to 50%. The temperature of the water W is in the range of 1 to 30 ° C. Tap water can be used for the water (W). There is no restriction | limiting in particular in water W, Any of soft water, hard water, and pure water may be sufficient.

When the ratio of water (W) injected into the kneader 11 is less than 20%, fine powders (P1, P2, P3) of hydrophilic polymer (2), synthetic resin (3), plant fiber (4) and inorganic compound (5) , P4) cannot be sufficiently kneaded, and the fluid mixture 6 cannot be made. When the proportion of water (W) injected into the kneader 11 exceeds 50%, the viscosity of the mixture 6 is remarkably lowered, and the mixture 6 is heated to provide moisture in the pellet manufacturing process S2 described later. It is necessary to evaporate. In addition, when the mixture 6 is heated to evaporate water, the fine powder P1 of the hydrophilic polymer 2 contained therein is deteriorated into a paste, and the viscosity of the mixture 6 is remarkably increased. When the temperature of the water W injected into the kneader 11 exceeds 30 ° C, the fine powder P1 of the hydrophilic polymer 2 is changed into a paste depending on the kind of the hydrophilic polymer 2 to be kneaded. There is a case.

In the pellet manufacturing process S2, the mixture 6 discharged from the kneader 11 is screw-extruded from the hopper 14 through the pipe 13 and flows into the inside of the granulator 12. Inside the granulator 12, the mixture 6 is moved from the rear end 12a of the granulator 12 toward the tip 12b while being pressed by the rotation of a screw (not shown).

The mixture 6 is discharged to the outside of the granulator 12 through a punching plate (not shown) provided in the tip portion 12b of the granulator 12. The mixture 6 is molded into a cylindrical shape by a plurality of circular openings formed in the punching plate and cut into predetermined lengths. Thereafter, the mixture 6 is naturally dried to produce a plurality of pellets 1A.

In the method for producing pellet 1A, fine powders (P1, P2, P3, P4) of hydrophilic polymer (2), synthetic resin (3), plant fiber (4) and inorganic compound (5) are sufficiently filled with water (W). Since kneading, these fine powders P1, P2, P3, P4 can be disperse | distributed substantially uniformly to the manufactured pellet 1A. The fine powders (P1, P2, P3, P4) have a particle diameter in the range of 30 to 200 µm, so that the specific gravity or volume of these fine powders (P1, P2, P3, P4) is not significantly different. None of P2, P3, and P4 is localized in the portion of the pellet 1A.

FIG. 3 is a process schematic diagram showing a method of manufacturing the foamed material 7 made of the pellet 1A of FIG. 1. The foam material 7 is manufactured using the extruder 15, shape | molded in plate shape by the die (not shown) provided in the front-end | tip part 15b of the extruder 15, and the molded article of a predetermined shape is produced.

In the manufacturing method of the foam material 7, a plurality of pellets 1A are introduced from the hopper 16 installed at the rear end 15a of the extruder 15, and the pellets 1A enter the inside of the extruder 15. do.

The pellet 1A is heated inside the extruder 15 and kneaded while the pellet 1A is pressed by the rotation of a screw (not shown) of the extruder 15. Inside the extruder 15, the hydrophilic polymer 2 and the synthetic resin 3 are dissolved, and the pellet 1A is a high temperature fluid (not shown) of a predetermined temperature. In the fluid, fine powders P3 and P4 of the plant fiber 4 and the inorganic compound 5 are dispersed substantially uniformly. In addition, since the pellet 1A collapses at a pressure of 100 to 490 N, the pellet 1A can be easily broken by the rotation of the screw.

When the pellet 1A turns into a hot fluid inside the extruder 15, the moisture contained in the pellet 1A vaporizes instantly, and the moisture changes to a vapor having a volume of about 1200 times or more the volume before vaporization. A plurality of bubbles 8 are formed in the fluid by vaporization of water. The fluid expands at a predetermined magnification with the expansion of the bubble 8 at the moment of extrusion from the die. The fluid is extruded from the die and then cooled and solidified to form a plate-shaped foam material 7.

In the manufacturing method of the foamed material 7 shown in FIG. 3, since the pellets 1A in which the fine powders P1, P2, P3, and P4 are distributed substantially uniformly are used, the oil formed by heating and kneading the pellets 1A is shown. The fine powders P3 and P4 can be uniformly dispersed in the animal, and any one of the fine powders P3 and P4 is not localized on a part of the manufactured foam material 7, so that the foam material 7 The strength is not partially lowered.

In the foam material 7, the hydrophilic polymer 2 forms a film surrounding the bubble 8. The expansion ratio of the foam material 7 is 20 to 80 times per unit volume of the fluid before foaming. The burned calories of the foam 7 are in the range of 4500-6000 kPa / kg.

In the extruder 15, 1 A of pellets which entered inside are heated at 150-190 degreeC. When the heating temperature of the pellet 1A is less than 150 ° C, the fine powders P1 and P2 of the hydrophilic polymer 2 and the synthetic resin 3 do not dissolve in the extruder 15, and the high temperature oil of the pellet 1A You can't do it as an animal. When the heating temperature of the pellet 1A exceeds 190 ° C, the properties of the hydrophilic polymer 2, the synthetic resin 3, and the plant fiber 4 change, and in particular, the plant fiber 4 becomes yellow or black. Thereby, the foam member 7 may be discolored.

In the pellet 1A, the weight ratio of the hydrophilic polymer 2 to the total weight is 5 to 69.5%, and the weight ratio of the synthetic resin 3 to the total weight is in the range of 10 to 50%. In the pellet 1A, the weight ratio of the plant fiber 4 to the total weight is 20 to 60%, and the weight ratio of the inorganic compound 5 to the total weight is in the range of 0.5 to 35%. It is preferable that the weight ratio of the hydrophilic polymer 2 to the total weight of the pellet 1A is in the range of 20 to 65.5%.

In addition, in the method for producing the pellet 1A, the weight ratio of the hydrophilic polymer 2 to the total weight of the flowable mixture 6 produced in the kneader 11 is 5 to 69.5%, and the total weight of the flowable mixture 6. The weight ratio of synthetic resin (3) to 10 to 50%, the weight ratio of plant fiber (4) to the total weight of the flowable mixture (6) is 20 to 60%, the inorganic compound to the total weight of the flowable mixture (6) ( The weight ratio of 5) is in the range of 0.5 to 35%.

If the weight ratio of the hydrophilic polymer (2) is less than 5%, the adhesive function of the hydrophilic polymer (2) cannot be sufficiently used, so that the synthetic resin (3), the plant fiber (4), and the inorganic compound (5) are bonded by the hydrophilic polymer (2). It is not possible to produce pellets 1A having a predetermined shape.                     

When the weight ratio of the synthetic resin 3 is less than 10%, the strength of the foamed material 7 made of the pellet 1A is remarkably lowered, and the foamed material 7 is easily broken. When the weight ratio of the synthetic resin 3 exceeds 50%, the burning calories of the pellets 1A increase, and as a result, the burning calories of the foam material 7 made of the pellets 1A exceeds 6000 mW / kg. .

When the weight ratio of the plant fiber 4 is less than 20% and the weight ratio of the inorganic compound 5 is less than 0.5%, the burning calories of the pellet 1A cannot be reduced, and the foamed material 7 made of the pellet 1A can be reduced. Can not reduce burning calories.

When the weight ratio of the plant fiber 4 exceeds 60% or the weight ratio of the inorganic compound 5 exceeds 35%, the plant fiber 4 or the inorganic compound 5, which does not exhibit fluidity even when heated, is extruded ( Interfering with the fluidity of the fluid in 15), the quantity of fluid cannot be extruded from the die, resulting in poor extrusion of the fluid. In addition, when manufacturing the foam material 7 from the pellet 1A, the plant fiber 4 concentrates on a part of die | dye, and the die may be clogged by this, and therefore, it is important to manufacture the foam material 7 continuously for a long time. It becomes difficult. In addition, the strength of the foamed material 7 produced from the pellets 1A decreases.

The pellet 1A has a water content in the range of 5 to 30% based on the total weight of the pellet 1A. If the moisture content of the pellet 1A is less than 5%, the foaming of the hot fluid inside the extruder 15 becomes insufficient when the foaming material 7 is manufactured using the pellet 1A, and the pellet 1A The foaming ratio of the foamed material 7 produced by this will be 20% or less. When the moisture content of the pellet 1A exceeds 30%, the pellet 1A becomes remarkably brittle, which easily collapses at a pressure of less than 100 N, and cannot maintain its shape.                     

When the length of the pellet 1A exceeds 10.0 mm and the diameter exceeds 5.0 mm, the pellet 1A becomes larger than necessary, and the pellet 1A does not quickly collapse and dissolve within the extruder 15. The screwing of the extruder 15 and the pulsation may occur due to the rotation of the screw, and the fluid may cause excessive foaming or poor foaming inside the extruder 15. If the volume specific gravity of the pellet 1A is less than 0.2, the screw of the extruder 15 may cause idle rotation, and pulsation may occur in rotation of the screw.

When the particle diameters of the fine powders (P1, P2, P3, P4) of the hydrophilic polymer (2), the synthetic resin (3), the plant fiber (4), and the inorganic compound (5) are less than 30 µm, they are less than 30 µm. Since several grinding | pulverization processes are required to process it, the production cost of the pellet 1A will rise. When the particle diameter of these fine powders P1, P2, P3, P4 exceeds 200 micrometers, the fine powders P1, P2, P3, P4 will disperse | distribute at the time of manufacture of pellet 1A, and the pellet 1A These fine powders (P1, P2, P3, P4) cannot be uniformly dispersed.

4 is a perspective view of the pellet 1B shown as another example. This pellet 1B constitutes the raw material of the foamed material 7 (molded product) produced using the technique of extrusion molding similarly to FIG. 1 (refer FIG. 6).

The pellet 1B is made of fine powder P1 (first fine powder) formed of the hydrophilic polymer 2 and fine powders P3, P4 formed of the plant fiber 4 and the inorganic compound 5 (second fine powder). Powder) in a predetermined ratio (see Fig. 5). The pellet 1B is a solid having a prismatic shape, and contains a predetermined amount of water.

The amount of water and the specific gravity of the pellet 1B with respect to the total weight of the pellet 1B are the same as those of FIG. The pellet 1B disintegrates at a pressure of 100 to 490 N and is dissolved at a temperature of 150 to 190 ° C.

In the pellet 1B, fine powder P1 of the hydrophilic polymer 2, fine powder P3 of the plant fiber 4, and fine powder P4 of the inorganic compound 5 are substantially uniformly dispersed. These fine powders P1, P3, P4 have the particle diameter in the range of 30-200 micrometers. The same material as that of Fig. 1 is used for the hydrophilic polymer (2), the plant fiber (4), and the inorganic compound (5).

FIG. 5 is a process schematic diagram showing the method for producing the pellet 1B of FIG. 4. The pellet 1B is manufactured in the same manner as in FIG. 1 by using a kneader 11 to produce a fluid mixture 6, a mixture production step S1, and a granulator 12. It is formed in the pellet manufacturing process (S2) which manufactures the pellet 1B by the following.

In the mixture preparation step (S1), fine powders (P1, P3, P4) of hydrophilic polymer (2), plant fiber (4) and inorganic compound (5) are introduced into the kneader (11), and water (W) is kneaded. Is injected into the machine (11). Inside the kneader 11, these fine powders P1, P3, P4 are kneaded with water W by rotation of a screw, and the viscous clay-like fluid mixture 6 is manufactured. The ratio of the water (W) injected into the kneader 11 (weight ratio of water applied in the mixture production process) and the temperature of the water (W) are the same as those in FIG.

In the pellet manufacturing process S2, the mixture 6 is screw-extruded from the hopper 14 through the pipe 13 and flows into the inside of the granulator 12. Inside the granulator 12, the mixture 6 is moved toward the tip 12b of the granulator 12 while being pressed by the rotation of a screw (not shown). The mixture 6 is discharged to the outside of the granulator 12 from the punching plate (not shown) provided in the tip portion 12b of the granulator 12. The mixture 6 is shaped into a columnar shape by a plurality of rectangular openings formed in the punching plate and cut into predetermined lengths. Thereafter, the mixture 6 is naturally dried to produce a plurality of pellets 1B.

In the method for producing the pellet 1B, the fine particles (P1, P3, P4) of the hydrophilic polymer (2), the plant fiber (4), and the inorganic compound (5) are sufficiently kneaded together with the water (W). These fine powders P1, P3, P4 can be dispersed substantially uniformly in 1B). The fine powders (P1, P3, P4) have a particle diameter in the range of 30 to 200 µm, so that the specific gravity or volume of these fine powders (P1, P3, P4) is not significantly different. None of these are localized in a part of the pellet 1A.

FIG. 6 is a process schematic diagram showing a method of manufacturing the foamed material 7 made of the pellet 1B of FIG. 4. The foam material 7 is manufactured using the extruder 15, is extruded from the die (not shown) provided in the extruder 15, and is shape | molded in plate shape, and the molded article of a predetermined shape is produced.

Into the hopper 16 of the extruder 15, fine powder P2 of a predetermined amount of polyolefin-based thermoplastic synthetic resin 3 is introduced together with a plurality of pellets 1B. In the inside of the extruder 15, the fine powder P2 of the pellet 1B and the synthetic resin 3 is heated, and they are kneaded by the rotation of the screw (not shown) of the extruder 15, and the hydrophilic polymer 2 and The fine powders P1 and P2 of the synthetic resin 3 are dissolved into a high temperature fluid at a predetermined temperature.

The inside of the extruder 15 vaporizes the water contained in the pellet 1B in an instant, and changes the water into a gas having a volume of about 1200 times or more of the unit volume before vaporization, thereby increasing the number of bubbles 8 inside the fluid. Is formed. The flow expands at a given magnification with the expansion of the bubble 8 at the moment it is extruded from the die. The fluid is extruded from the die and then cooled and solidified to form a plate-shaped foam material 7.

In the foam material 7, the hydrophilic polymer 2 forms a film surrounding the bubble 8. The expansion ratio of the foam material 7 is 20 to 80 times per unit volume of the fluid before foaming. The calorie burned in the foam 7 is in the range of 4500 to 6000 kPa / kg. The heating temperature of the extruder 15 for pellet 1B and fine powder P2 is the same as that of FIG.

In the manufacturing method of the foamed material 7 shown in FIG. 6, since the fine powder P1, P3, P4 disperse | distributes substantially uniformly, the pellet 1B and the fine powder P2 of the synthetic resin 3 are used, The fine powders P3 and P4 can be uniformly dispersed in the fluid formed by heating and kneading 1A, and any one of the fine powders P3 and P4 is localized in a part of the manufactured foam material 7. There is no work, and the strength of the foam member 7 does not partially decrease.

In the pellet 1B, the weight ratio of the hydrophilic polymer 2 to the total weight is 5 to 66.5%, the weight ratio of the plant fiber 4 to the total weight is 20 to 60%, and the inorganic compound to the total weight ( The weight ratio of 5) is in the range of 0.5 to 35%. It is preferable that the weight ratio of the hydrophilic polymer 2 to the total weight of the pellet 1B is in the range of 20 to 65.5%.

In addition, in the method for producing the pellet 1B, the weight ratio of the hydrophilic polymer 2 to the total weight of the fluid mixture 6 produced in the kneader 11 is 5 to 69.5%, and the total weight of the fluid mixture 6 is present. The weight ratio of plant fiber (4) to 20 to 60%, the weight ratio of inorganic compound (5) to the total weight of the flowable mixture (6) is in the range of 0.5 to 35%.                     

If the weight ratio of the hydrophilic polymer (2) is less than 5%, the adhesive strength of the hydrophilic polymer (2) is reduced, the hydrophilic polymer (2) can not bond the plant fiber (4) and the inorganic compound (5), The pellet 1B cannot be manufactured.

When the weight ratio of the plant fiber 4 is less than 20% and the weight ratio of the inorganic compound 5 is less than 0.5%, the burning calories of the pellet 1B cannot be reduced, and as a result, the foamed material produced from the pellet 1B ( The burning calorie of 7) exceeds 6000 kcal / kg.

When the weight ratio of the plant fiber 4 exceeds 60% or the weight ratio of the inorganic compound 5 exceeds 35%, the plant fiber 4 or the inorganic compound 5, which does not exhibit fluidity even when heated, is extruded ( Interfering with the fluidity of the fluid in 15), the quantity of fluid cannot be extruded from the die, resulting in poor extrusion of the fluid. In addition, when manufacturing the foam material 7 from the pellet 1B, the plant fiber 4 concentrates in a fixed part of die | dye, and a die may be clogged by this, so that the foam material 7 is continuously manufactured for a long time. It becomes difficult.

In the manufacturing method of manufacturing the foam material 7 from the pellet 1B, the weight ratio of the synthetic resin 3 to be injected into the extruder 15 is 10 to 50 to the total weight of the pellet 1B to be injected into the extruder 15. It is preferable to exist in the range of%.

The pellet comprises at least one fine powder (P2) selected from fine powder (P1) (first fine powder) of hydrophilic polymer (2), polyolefin thermoplastic resin (3), plant fiber (4) and inorganic compound (5). What is necessary is just a mixture which mixed P3, P4) (2nd fine powder). For example, a pellet is a mixture of fine powder P1 of the hydrophilic polymer 2 and fine powder P2 of synthetic resin 3, and pellets fine powder of fine powder P1 of the hydrophilic polymer 2 and plant fiber 4 The mixture of the powder (P3) and the pellet may be a mixture of the fine powder (P1) of the hydrophilic polymer (2) and the fine powder (P4) of the inorganic compound (5). The pellet is a mixture of fine powder (P1) of hydrophilic polymer (2), fine powder (P2, P3) of synthetic resin (3) and plant fiber (4), and pellet is fine powder (P1) of hydrophilic polymer (2). And a fine powder (P2, P4) of synthetic resin (3) and inorganic compound (5).

The pellet is not limited to a cylindrical shape or a prismatic shape showing the shape, and the shape can be changed in the manufacturing process of the pellet.

The pellet according to the present invention is a mixture of a fine powder (first fine powder) formed of a hydrophilic polymer and a fine powder (second fine powder) formed of at least one of a polyolefin-based thermoplastic synthetic resin and a plant fiber and an inorganic compound. These fine powders are substantially uniformly dispersed in the pellets. The pellets have a particle diameter of 30 to 200 µm in the form of fine powders, and the specific gravity and volume of these fine powders do not differ greatly, and are any of fine powders of hydrophilic polymers, synthetic resins, plant fibers, and inorganic compounds. Is not omnipresent in a portion of the pellet.

The pellet can prevent the dispersion of fine powder in the inside of the extruder when the molded article is produced using the pellet, and neither one of the plant fibers and the fine powder of the inorganic compound is localized on a part of the molded article. The fall of the strength of a molded article can be prevented.

The pellet has a water content in the range of 5 to 30% based on the total weight thereof, and when the pellet is put into the extruder, the pellet is dissolved to form a high-temperature fluid, and the water vaporizes, thereby allowing a large number of bubbles in the fluid. Since it is formed, it is possible to easily prepare the foam using the pellets. The foamed material and its molded article can be used in a wide range of fields, for example, as a cushioning material, a heat insulating material and the like.

Pellets containing plant fibers and inorganic compounds can reduce the burned calories at the time of incineration of molded articles made from pellets as compared with the case where they are formed only of synthetic resins.

In the manufacturing method of the pellet which concerns on this invention, the fine powder which forms a pellet can be disperse | distributed uniformly, and the uneven distribution of the fine powder in a pellet can be prevented. Therefore, when producing a molded product from pellets using an extruder, fine powder is uniformly dispersed in the fluid flowing inside the extruder, so that the quantitative fluid can be smoothly extruded from the die of the extruder, and the die is not clogged. The molded article can be made continuously for a long time using an extruder.

According to the present invention, when producing a molded article by an extruder, it is possible to prevent the dispersion of the raw material in the inside of the extruder, and to provide a pellet and a method for producing the molded article and the molded article that can be used to make the molded article continuously for a long time using the extruder can do.

Claims (8)

As a pellet constituting the raw material of the molded article produced by the molding process, A mixture of a first fine powder formed of a hydrophilic polymer, a polyolefin thermoplastic synthetic resin, and a second fine powder formed of at least one of plant fibers and an inorganic compound, and containing a predetermined amount of water, The particle diameter of the first and second fine powder is in the range of 30 to 200 μm, the moisture content of the pellet is in the range of 5 to 30% of the total weight of the pellet, and the first and second fine powder are A pellet, which is uniformly dispersed in the pellet. According to claim 1, wherein the weight ratio of the hydrophilic polymer to the total weight of the pellet is 5 to 69.5%, the weight ratio of the synthetic resin to the total weight of the pellet is 10 to 50%, the plant to the total weight of the pellet 20 to 60% by weight of the fiber, the weight ratio of the inorganic compound to the total weight of the pellet is in the range of 0.5 to 35%. The pellet according to claim 1 or 2, wherein the pellet disintegrates at a pressure of 100 to 490 N and is dissolved at a temperature of 150 to 190 ° C. The pellet according to claim 1 or 2, wherein the volume specific gravity of the pellet is in the range of 0.2 to 1.0. The pellet according to claim 1 or 2, wherein the pellets have a substantially cylindrical shape, the length of the pellets is in the range of 0.5 to 10.0 mm, and the diameter of the pellets is in the range of 1.0 to 5.0 mm. As a method for producing pellets constituting the raw material of the molded article produced by the molding process, Water is added to the first fine powder formed of a hydrophilic polymer, the second fine powder formed of at least one of a polyolefin-based thermoplastic synthetic resin, a plant fiber and an inorganic compound, and the first and second fine powders are kneaded together with the water. A mixture manufacturing step of preparing a fluid mixture, and a pellet manufacturing step of wet granulating the fluid mixture, followed by drying to produce the pellet, The particle diameter of the said 1st and 2nd fine powder is 30-200 micrometers, and the ratio of the said water added in the said mixture manufacturing process is based on the total weight of the said 1st and 2nd fine powder kneaded in the said mixture manufacturing process. Method for producing pellets, characterized in that in the range of 20 to 50%. Using the pellet produced by the method of Claim 6, the pellet was foamed and molded into the predetermined shape, The molded article characterized by the above-mentioned. The molded article according to claim 7, wherein the pellets are foamed with an extruder and molded into a predetermined shape.

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