JP5930661B2 - Method for recycling fiber reinforced plastic waste, recycled molded body, and recycling apparatus - Google Patents

Description

  The present invention relates to recycling of fiber reinforced plastic waste materials, and more specifically, a recycling method and recycled molded body for obtaining fiber reinforced plastics having high characteristics from fiber reinforced plastic waste materials recovered from discarded products. And a recycling apparatus.

  In recent years, products such as air conditioners, televisions, refrigerators, washing machines, etc. are widely used in general households as income levels improve in Japan. As a result, the amount of waste of these products tends to increase year by year, and the amount of plastic waste is also increasing accordingly. The majority of plastic waste has been disposed of by incineration or landfill, but global warming due to the release of carbon dioxide by incineration, environmental pollution due to the production and scattering of dioxins by incineration of plastics containing chlorine compounds, bulky plastic The shortage of landfills due to the increase in waste has become a major social problem, and the recycling of plastic waste has become an urgent issue to be solved.

  Under such circumstances, the Home Appliance Recycling Law was enacted in April 2001 for the purpose of effective use of resources and reduction of waste. According to the law, it is obliged to recycle four home appliances such as air conditioners, televisions, refrigerators and washing machines, and the re-commercialization rate of each product is air conditioners 70% or more, televisions 55% or more, refrigerators 60% or more, washing machines 65 The legal reference value is defined as% or more.

  Following the enforcement of the Home Appliance Recycling Law, research and development has progressed in various areas regarding the recycling of plastic materials used in discarded products (hereinafter referred to as “plastic waste materials”). Therefore, based on the idea of resource recycling, so-called material recycling, in which plastic waste material is processed again into a plastic member of a product, is attracting attention.

However, plastic waste from products that have been used for a long period of time often contains foreign substances such as sand dust, metal powder, rust, water scales, detergents, and detergent waste that are derived from the usage environment. If the foreign matter remains, the recycled plastic member is deteriorated in physical properties and defective in appearance, and long-term reliability is deteriorated. For this reason, it is very difficult to recycle plastic waste materials as durable consumer goods such as high-performance plastic members, for example, four items of home appliances. Many of the plastic waste materials are recycled as thermal fuel, Cascade recycling, which is recycled as low-performance plastic members, such as hangers and flower pots, has become the mainstream.

In order to solve such a problem, for example, in Patent Document 1, a pulverization process for pulverizing plastic waste material, a foreign substance removal process for removing foreign substances from the pulverized product, and pelletization for pelletizing the pulverized product from which foreign substances have been removed A method for producing a reclaimed molded body (corresponding to a reclaimed plastic material in Patent Document 1) including a process is disclosed. In the pulverization step, plastic waste is pulverized using a screen mesh of 4 mm or more and 10 mm or less, and plastic fine powder, metal powder, dust or the like of 2 mm or less is removed using a vibration sieve. Foreign matter removing step, air classification or gravity separation, subjected to a metal screening, we divided foreign matter from the pulverized product. In the pelletizing step, the pulverized product from which foreign substances have been removed is melted and kneaded by a heat molding machine (corresponding to the extruder in Patent Document 1) to be regenerated as pellets. In the pelletization process, the test sieve US standard no. A screen mesh containing 120 (screen opening size 0.125 mm) or finer mesh is used. The removal of foreign matters not only in the pulverization step and foreign matter removal step, but also in the pelletizing step achieves the quality of the recycled molded body and the efficiency of the regeneration.

JP 2003-340315 A

  By the way, in recent years, for household appliance parts, automobile parts, aircraft parts, housing building materials, etc., fiber fillers such as glass and carbon are used for the purpose of high functionality such as heat resistance, high strength, high rigidity, weight reduction, and metal substitution. The use of reinforced plastics (hereinafter referred to as “fiber reinforced plastics”) is increasing. For example, polypropylene can increase resistance to heat, such as rigidity and creep resistance, by blending glass fiber with a large elastic modulus, so it has high rigidity and heat resistance such as a water tank of a washing machine with a drying function and a drying fan. Is widely used for components that require the

  However, when the waste material of such fiber reinforced plastic is recycled by the technique of Patent Document 1, the fibrous filler breaks due to the screen mesh of the heat molding machine in the pelletizing process. The problem arises that the mechanical strength is significantly reduced.

  The present invention has been made in order to solve the above-mentioned problems, and its purpose is to optimize the opening size of the screen mesh of the heat molding machine and suppress the breakage of the fibrous filler, thereby achieving high-performance regenerative molding. An object of the present invention is to provide a method for recycling fiber-reinforced plastic, a recycled molded body, and a recycling apparatus that can obtain a body.

  As a result of intensive studies to achieve the above-mentioned problems, the present inventors have completed the present invention. That is, the present invention is as follows.

  The method for recycling fiber reinforced plastic waste material according to the present invention includes a crushing step for crushing fiber reinforced plastic waste material to obtain a crushed material, a sieving process for removing foreign material from the crushed material by sieving, and removing the foreign material. A heat forming step of heat-melting and extruding the crushed material, and the heat forming step is to perform extrusion using a screen mesh having an opening size of 0.3 mm or more and 0.6 mm or less. Features.

  In the sieving step, it is preferable to use a sieve having an opening size of 0.08 times or more and 0.5 times or less the opening size of the screen mesh used in the crushing step.

  In the crushing step, it is preferable to crush the fiber-reinforced plastic waste material using a screen mesh having an opening size of 10 mm or more and 20 mm or less.

  In the sieving step, sieving is preferably performed in a liquid, and the specific gravity of the liquid is preferably less than the specific gravity of the fiber-reinforced plastic waste material.

  The recycled molded body of the present invention is preferably obtained by the above recycling method.

  The apparatus for recycling fiber reinforced plastic waste material according to the present invention includes a crusher that crushes fiber reinforced plastic waste material into crushed material, a sieve that removes foreign material from the crushed material, and the crushed material from which the foreign material has been removed. A heating molding machine that heats and melts and extrudes, and the heating molding machine has a screen mesh for removing foreign substances from the crushed material, and the screen mesh opening size of the heating molding machine is 0.3 mm. It is above and 0.6 mm or less, It is characterized by the above-mentioned.

  The crusher has a screen mesh for crushing the fiber-reinforced plastic waste material, and the mesh opening size is 0.08 times or more and 0.5 times or less the screen mesh opening size of the crusher. Preferably there is.

  The opening size of the screen mesh of the crusher is preferably 10 mm or more and 20 mm or less.

  The sieve is preferably a wet sieve, and preferably has a liquid having a specific gravity less than that of the fiber-reinforced plastic waste material.

  According to the present invention, it is possible to efficiently remove foreign substances from fiber reinforced plastic waste material and to recycle the fiber reinforced plastic waste material for molding a recycled product having high characteristics by suppressing breakage of the fibrous filler. A method can be provided. Furthermore, the reproduction | regeneration molded object and recycling apparatus obtained by it can be provided.

It is a flowchart which shows the example of the recycling method of the fiber reinforced plastics of this invention. It is a figure showing the measurement result of the long-term stability of test piece a1, a2, a3, a4, a5. It is a figure showing the measurement result of the long-term stability of test piece b1, b2, b3, b4, b5. It is a figure showing the measurement result of the long-term stability of test piece c1, c2, c3, c4, c5. It is a figure showing the measurement result of the long-term stability of test piece d1, d2, d3, d4, d5.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. The recycling apparatus of the present invention includes a crusher that crushes fiber reinforced plastic waste material into crushed material, and the crusher crushes fiber reinforced plastic waste material roughly, and crushes finer than the coarse crusher. A pulverizer. The recycling apparatus includes a foreign matter removing device for removing foreign matter. The foreign matter removing device is, for example, a metal sorter that sorts metal-based crushed materials, or a wind sorter that sorts low-bulk specific gravity crushed materials. Including a sieve for removing foreign substances from finely crushed materials. Furthermore, the recycling apparatus includes a heat molding machine that heats and melts and extrudes the finely crushed material, and an injection molding machine that creates a recycled molded body. The operation of each part of the recycling apparatus will be described with reference to FIG.

  FIG. 1 is a flowchart showing an example of a method for recycling fiber reinforced plastic waste material according to the present invention. In the description of the recycling method, the step is described as “S”, and each process is distinguished by a number. First, used products discarded from homes and the like, for example, air conditioners, televisions, refrigerators, washing machines, and the like are collected (S101). Then, the used products are disassembled by a conventionally known appropriate method, and fiber reinforced plastic waste materials such as drum-type washing and drying machine water tanks and air conditioner fans, and large metal waste materials such as compressors and heat exchangers are used as parts. Each is collected (S102).

  Here, the fiber-reinforced plastic waste material subject to the present invention is not particularly limited. For example, polyethylene, polypropylene, polystyrene, AS resin, ABS resin, methacrylic resin, fluororesin, saturated polyester, polyamide, polyacetal It is preferably a thermoplastic resin such as resin, polycarbonate, polycarbonate-ABS resin, vinyl chloride resin, polysulfone. Further, the fibrous filler used in the fiber reinforced plastic waste material is not particularly limited. For example, alkali-containing glass fiber, low alkali glass fiber, alkali-free glass fiber, carbon fiber, aramid fiber, boron It is preferably a fiber.

  Next, the fiber-reinforced plastic waste material separated and recovered in S102 is roughly crushed with a coarse crusher (S103). The rough crusher is a large crusher such as an impact crusher or a shear crusher. The crushed material after rough crushing is hereinafter referred to as “crushed material”. The particle size of the coarsely crushed material is not particularly limited, but is preferably 10 mm or more, and more preferably 40 mm or more. Moreover, it is preferable that the particle size of a coarsely crushed material is 80 mm or less, and it is more preferable that it is 60 mm or less. If the particle size of the coarsely crushed material is less than 10 mm or more than 80 mm, the metal selection accuracy in the next process tends to be reduced. Further, if the particle size is less than 10 mm, it takes a long time for coarse crushing. Therefore, there is a tendency that the coarsely crushed material of the fiber reinforced plastic waste material is melted or thermally oxidized, and when the particle size exceeds 80 mm, the bulk specific gravity is reduced and the workability in the subsequent processes is adversely affected. There is a tendency. Specifically, it is particularly preferable to roughly pulverize so that the particle size is about 60 mm.

  Subsequently, the coarsely crushed material obtained in S103 is sorted into a metal-based crushed material and a fiber-reinforced plastic-based crushed material formed of iron, copper, aluminum or the like with a metal sorter (S104). The metal sorter performs, for example, sorting of iron using magnetic force and sorting of copper and aluminum using overcurrent. When performing both sorting using magnetic force and sorting using eddy current, the order is not particularly limited, but from the viewpoint of efficiency, iron is first removed by magnetic force, and then copper and aluminum are removed by eddy current. It is preferable.

  Subsequently, it is preferable to include a step (S105) of selecting and removing the low bulk specific gravity crushed material. Here, the low bulk specific gravity crushed material means a crushed material having a bulk specific gravity of 0.3 or less, and examples thereof include a polyurethane-based heat-insulated material crushed material and a polystyrene foam-based crushed material. The low bulk density crushed material is sorted and removed using a wind power sorter, and the wind bulk sorter can sort and remove the low bulk density crushed material by a conventionally known appropriate method. By providing this process, workability of the subsequent processes is improved.

  Next, the fiber-reinforced plastic crushed material obtained through the steps up to S105 is finely crushed (S106). This crushing process is performed using, for example, a fine crusher such as a shearing crusher. The crushed material after pulverization is hereinafter referred to as “fine crushed material”. The crushing diameter of the fine crusher, that is, the opening size A of the screen mesh of the fine crusher is not particularly limited, but is preferably 10 mm or more and 20 mm or less. If it is less than 10 mm, the fiber filler contained in the fiber reinforced plastic waste tends to break, and if it exceeds 20 mm, it tends to adversely affect the biting of the screw of the heating molding machine in step S109 described later. Moreover, when less than 10 mm or more than 20 mm, the removal efficiency and productivity of the foreign material adhering to the finely crushed material in step S107 described later tend to decrease. Specifically, the screen mesh opening size A is particularly preferably 10 mm or more and 14 mm or less for the reason of easy handling in step S109 described later. In this embodiment, the opening size A is 12 mm.

Next, foreign matter is removed from the finely pulverized product obtained in S106 using a sieve (S107). In other words, foreign matters passing through the sieve are removed from the finely crushed material by sieving. The method of sieving used in this sieving process is not particularly limited, but is preferably a cylindrical rotary type, a vibration type, or a horizontal circular motion type, and a cylindrical rotary type having high scrubbing and scumming effects, such as Trommel. Particularly preferred. In addition, the weaving method of the wire mesh of the sieve is not particularly limited, but a crimp weave, double crimp weave, flat top weave, lock clip that can obtain a scrubbing effect due to physical contact between the metal mesh unevenness and crushed material Woven is preferred. By S107, foreign substances adhering to the finely pulverized material, such as sand dust, metal powder, rust, water scale, etc., can be removed.

  Here, because the foreign matter adhering to the finely crushed material is efficiently removed and the raw material recovery rate (yield) and the production efficiency are increased, the sieve opening size B is the mesh size of the screen mesh of the fine crusher. It is preferably 0.08 times or more and 0.5 times or less of size A, particularly preferably 0.15 times or more and 0.2 times or less. By setting the sieve opening size B to 0.08 times or more of the opening mesh size A of the screen mesh of the fine crusher, the removal rate of foreign matters is increased, and a regenerated molded product having high characteristics can be obtained. In addition, by setting the sieve opening size B to 0.5 times or less than the opening mesh size A of the screen mesh of the fine crusher, the raw material recovery rate of the finely crushed material becomes high, and the profitability and the recycling rate Can be increased.

  Furthermore, the sieve is preferably a wet sieve that performs a sieving process in a liquid. By using a wet sieve, water-soluble foreign matters such as detergents and organic stains adhering to finely crushed materials can be simultaneously removed in addition to the foreign matters described above. Furthermore, generation | occurrence | production of static electricity can be prevented and the reattachment to the finely crushed material of the removed foreign material and clogging of a sieve can be suppressed.

  Here, the specific gravity of the liquid used for the wet sieve is less than the specific gravity of the finely crushed material, that is, the recovered fiber reinforced plastic waste material, in order not to reduce the scrubbing effect due to the physical contact between the metal mesh irregularities and the crushed material. It is preferable that The liquid used for the wet sieve is particularly preferably water from the viewpoint that most of the fiber reinforced plastic has a specific gravity of 1.0 or more and environmental consideration. By using water, the cost of the sieving process can be suppressed, and the waste water treatment is facilitated.

  Next, additives such as an antioxidant, a metal deactivator, and a compatibilizer are added to the finely crushed material from which foreign matters have been removed in S107 as necessary, and mixed uniformly (S108). Furthermore, additives such as heat stabilizers, light stabilizers, antistatic agents, lubricants, fillers, copper damage inhibitors, antibacterial agents, and coloring agents are added in amounts that do not impair the effects of the present invention, if necessary. May be. Moreover, in the case of fiber reinforced polyolefin, you may add a carboxylic anhydride modified polyolefin type modifier in the quantity of the range which does not impair the effect of this invention as needed. If necessary, a fiber reinforced plastic of the same system as the finely crushed material may be added and mixed uniformly. In this case, there is no restriction | limiting in particular in the addition order of the fiber reinforced plastic of the same system | strain as various additives and a finely crushed material. In this way, various additives and fiber-reinforced plastics of the same system as finely crushed materials are added and mixed as necessary, so that high-grade fiber-reinforced plastics, especially home appliances that require high long-term reliability. It is possible to obtain a regenerated molded body that can be suitably used as a material for fiber-reinforced plastic members for office machines and office equipment. Here, it is preferable to mix the finely pulverized product with the additive and the finely pulverized product, which are added as necessary, with the same type of fiber reinforced plastic so as to be uniform. Such mixing can be performed by a conventionally known method such as a method using a tumbler mixer or the like.

  Next, the mixture obtained in S108 is heated and melted and extruded (S109). Here, the temperature of the heat melting and extrusion molding (hereinafter referred to as “heat molding”) step is T ° C. or higher, where T ° C. is the lowest temperature at which the entire mixture obtained in S108 is melted. Is preferable, and (T + 10) ° C. or higher is more preferable. Moreover, it is preferable that it is (T + 120) degrees C or less, and it is more preferable that it is (T + 60) degrees C or less. By setting the heating temperature in the heat forming step to T ° C. or higher, the entire mixture obtained in S108 can be sufficiently melted and easily formed. Moreover, the thermal deterioration of a fiber reinforced plastic can be suppressed by making the heating temperature of a thermoforming process into (T + 120) degreeC. The thermoforming machine used for the thermoforming is not particularly limited, and examples thereof include an extruder such as a single screw extruder or a multi-screw extruder.

  Here, the heat molding machine preferably has a screen mesh for removing foreign matters remaining in the finely crushed material, and preferably removes foreign matters that do not pass through the screen mesh. Is preferably reduced. However, when the screen mesh is made smaller, the fibrous filler tends to break, and the physical properties of the regenerated molded product tend to deteriorate. Further, the screen mesh is clogged with the fibrous filler, and the productivity of thermoforming is reduced. There is a tendency to decrease.

  Therefore, the mesh size C of the screen mesh of the apparatus used for heat forming in the present embodiment is preferably 0.3 mm or more and 0.6 mm or less. When the opening size C of the screen mesh of the apparatus used for heat forming is less than 0.3 mm, the breakage of the fibrous filler and the clogging of the screen mesh are promoted, and the physical properties and productivity of the regenerated molded product are remarkably lowered. Tend to. On the other hand, when the thickness exceeds 0.6 mm, breakage of the fibrous filler and clogging of the screen mesh are suppressed, but the removal rate of the foreign matters remaining in the finely crushed material is lowered, and the physical properties and long-term reliability of the regenerated molded body are reduced. Tend to decrease. Specifically, the mesh size C of the screen mesh of the apparatus used for heat forming is particularly preferably 0.4 mm or more and 0.5 mm or less. In the present embodiment, the opening size C is set to 0.4 mm. According to this embodiment, the foreign material adhering to a fiber reinforced plastic waste material is removed efficiently, and the reproduction | regeneration molded object with a high characteristic can be obtained by suppressing the breakage of a fibrous filler.

  Next, the heat-molded fiber reinforced plastic is made into a raw material (S110). Fiber reinforced plastic raw materials are granulated by methods such as sheet cutting, strand cutting, hot air cutting, underwater cutting, etc. Among these granulating methods, fiber reinforced plastic is used for later forming into a specific shape by injection molding. An underwater cut that can smoothly supply the raw material and can cope with a large amount of processing is particularly preferable.

  The fiber-reinforced plastic raw material is not particularly limited in shape, and may be in the form of pellets, sheets, films, pipes, etc., the type of heating molding machine, the mode of use, the required characteristics, etc. It may be determined as appropriate. The fiber-reinforced plastic raw material is preferably in the form of pellets because it is versatile as a raw material to be molded into various molded products such as sheets, films, and injection molded products, and is easy to handle. When the fiber reinforced plastic raw material is formed into pellets, the particle size is not particularly limited, but is preferably 8 mm or less in order to be sufficiently melted and uniformly kneaded in the cylinder of the injection molding machine. 5 mm or less is more preferable.

  Then, the fiber reinforced plastic raw material is put into an injection molding machine to create a regenerated molded body (S111). The injection molding machine is not particularly limited, and examples thereof include a screw inline type injection molding machine and a plunger type injection molding machine. If necessary, a fiber reinforced plastic of the same system as the fiber reinforced plastic raw material may be added and mixed uniformly. Thus, by adding and mixing the same fiber reinforced plastics as the fiber reinforced plastic raw material, high-grade fiber reinforced plastics, especially home appliances that require mechanical strength, creep resistance, and heat resistance, It is possible to obtain a recycled molded body that can be suitably used as a material for fiber-reinforced plastic members such as office equipment. Here, it is preferable to mix the fiber-reinforced plastic raw material and the same type of fiber-reinforced plastic so that they are uniform. Such mixing can be performed by a conventionally known method such as a method using a tumbler mixer or the like.

  The present invention does not have to include all the steps shown in FIG. 1, a crushing step of crushing fiber reinforced plastic waste material, a step of removing foreign matters contained in the fiber reinforced plastic waste material crushed using a sieve, Any material that includes at least a step of thermoforming a crushed fiber-reinforced plastic waste material from which foreign substances have been removed is included in the scope of the present invention.

  The regenerated molded article of the present invention is not particularly limited, but is preferably used for a product that is material-recycled. In this case, the product that is material-recycled is a group consisting of an air conditioner, a TV, a refrigerator, and a washing machine. It is preferable that the appliance is selected from the following.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.
<Preparation of test piece>
A waste water tank (material: 20% glass fiber reinforced polypropylene, specific gravity 1.04) is recovered by hand dismantling from the used drum type washing and drying machine collected in the market (S101) (S102), and using an impact crusher. Crushed roughly (S103). Next, after removing the metal-based crushed material mainly composed of iron from the coarsely crushed material using a magnetic separator, the metal-based crushed material mainly composed of copper and aluminum is removed using an eddy current sorter (S104). ). Then, lightweight materials, such as a foaming material, were removed using the hermetic circulation type wind power sorter (S105). Next, the fiber reinforced plastic crushed material obtained through S105 was finely crushed with a shearing type crusher (S106), and foreign matter was removed from the finely crushed material with a cylindrical rotating wet sieve (S107). Next, an appropriate amount of an antioxidant was added to the finely crushed product from which foreign matters had been removed, and the mixture was uniformly mixed with a tumbler mixer (S108). Subsequently, the mixture obtained in S108 was heat-molded at 230 ° C. using a biaxial melt-kneading extruder having a screw diameter of 45 mm (S109) to produce a pellet-like fiber-reinforced plastic raw material (S110). Then, it was put into a hopper of a 10-ton injection molding machine, and test pieces for measuring physical properties in accordance with ASTM were produced under injection molding conditions of a molding temperature of 230 ° C. and a mold temperature of 40 ° C. (S111).

Here, each test piece for measuring physical properties is the production conditions, that is, the shearing crushing apparatus of S106, that is, the screen mesh opening size A of the fine crushing machine, the cylindrical rotating wet sieve of S107, that is, the opening of the sieve It was produced by changing the size B and the opening size C of the screen mesh of the S109 biaxial melt-kneading extruder, that is, the thermoforming machine.
<Evaluation method>
(1) Foreign matter contamination amount A 100 mm × 100 mm × 1 mm hot press sheet was prepared from the fiber reinforced plastic raw material obtained in S110, and the foreign matter contamination amount was measured according to the contaminant measurement chart (JIS P 8208). .
(2) Raw material recovery rate X is the weight of the finely crushed material obtained in S106, Y is the weight after removing the foreign matter with the cylindrical rotating wet sieve of S107, and the recovered material amount is (Y / X ) X 100 (%)
Calculated from the formula.
(3) Extrusion Amount The amount of recycled plastic raw material discharged until clogging in the screen mesh was measured when thermoforming with a biaxial melt kneading extruder.
(4) Tensile strength and elongation Tensile strength and elongation were measured according to JIS K7113.
(5) Flexural strength and flexural modulus The flexural strength and flexural modulus were measured according to JIS K 7203.
(6) Measurement of Izod impact strength Izod impact strength was measured according to JIS K 7110.
(7) Long-term stability The bending strength was measured by a thermal stability test by standing at 140 ° C. in a constant temperature bath, and the relationship between aging time and bending strength was confirmed.

Hereinafter, the measurement results of (1) to (7) will be described with test pieces having different production conditions.
<Evaluation test 1>
In order to confirm the effect of the sieve opening size B, an evaluation test 1 was performed. That is, the mesh size A of the screen mesh of the fine crushing machine and the mesh size C of the screen mesh of the thermoforming machine are fixed, and the test piece is prepared by changing the mesh size B of the sieve. (1), (2 ) And (4) to (7) were evaluated.

First, test pieces a1, a2, a3, a4, and a5 were prepared under the following conditions: A = 12 mm, C = 0.4 mm, and B, and each evaluation was performed.
Test piece a1: B = 0.8 mm (= A × 0.067)
Test piece a2: B = 0.96 mm (= A × 0.08)
Test piece a3: B = 2.0 mm (= A × 0.17)
Test piece a4: B = 6.0 mm (= A × 0.5)
Test piece a5: B = 8.0 mm (= A × 0.67)
Next, test pieces were prepared using test pieces b1, b2, b3, b4, and b5 with A = 20 mm, C = 0.4 mm, and B as the following conditions, and each evaluation was performed.
Test piece b1: B = 1.34 mm (= A × 0.067)
Test piece b2: B = 1.6 mm (= A × 0.08)
Test piece b3: B = 3.4 mm (= A × 0.17)
Test piece b4: B = 10 mm (= A × 0.5)
Test piece b5: B = 13.4 mm (= A × 0.67)

Table 1 shows the evaluation results when A = 12 mm. Moreover, the measurement result of long-term stability is shown in FIG. The test piece a1 has a small sieve opening size B of 0.067 times the screen size A of the screen mesh of the fine crushing machine, so the raw material recovery rate is high, but the amount of foreign matter remaining is large, so that the elongation and Izod impact strength are high. It is falling. The test piece a5 has a small sieve opening size B, which is 0.67 times the screen mesh opening size A, so that the remaining amount of foreign matter is small, but the raw material recovery rate is low, so the productivity is poor. In test pieces a2, a3, and a4 in which the sieve opening size B is 0.08 times, 0.17 times, and 0.5 times the opening size A of the screen mesh of the fine crusher, It can be seen that the balance of the raw material recovery rate is good and the physical properties are also excellent.

  FIG. 2 is a measurement result of long-term stability when A = 12 mm, and is a diagram showing the relationship between the aging time of the thermal stability test and the physical property retention rate of the bending strength of each test piece. Referring to FIG. 2, it can be seen that the test pieces a2, a3, a4, and a5 having a small amount of foreign matter show long-term thermal stability. That is, since all the test pieces were added with the antioxidant under the same conditions, it can be seen that the heat stability time of the regenerated molded product increases as the amount of foreign matter decreases with the same amount of the antioxidant added. By adding a lot of antioxidants, long-term stability can be obtained even if the amount of residual foreign matter is large, but according to the recycling method of the present invention that can reduce the residual amount of foreign matter, fiber reinforcement The amount of additives used in plastic waste can be reduced, leading to cost reduction of recycled fiber reinforced plastic raw materials.

Table 2 shows each evaluation result when A = 20 mm. Moreover, the measurement result of long-term stability is shown in FIG. From Table 2, as in the case of A = 12 mm, the screen size B of the screen is 0.08 times, 0.17 times, and 0.5 times the screen size A of the screen mesh of the fine crusher. It can be seen that in the pieces b2, b3, and b4, the balance between the amount of foreign matter mixed and the raw material recovery rate is good, and the physical properties are also excellent.

  FIG. 3 is a measurement result of long-term stability when A = 20 mm, and is a diagram showing the relationship between the aging time of the thermal stability test and the physical property retention rate of the bending strength of each test piece. As in the case of A = 12 mm, it can be seen that the test pieces b2, b3, b4, b5 with a small amount of foreign matter show long-term stability.

From these results, test specimens a2, a3, a4, b2, b3, b4 are preferable, that is, the optimum range of the sieve opening size B with respect to the opening size A of the screen mesh of the fine crusher is A X0.08 ≦ B ≦ A × 0.5.
<Evaluation Test 2>
In order to confirm the effect of the opening size C of the screen mesh of the heat molding machine, an evaluation test 2 was performed. That is, the screen size A of the screen mesh of the fine crusher and the screen size B of the sieve are fixed, and the test screen is prepared by changing the screen size C of the screen mesh of the heat molding machine. (1) and (3 ) To (7) were evaluated.

First, test pieces c1, c2, c3, c4, and c5 were prepared under the following conditions: A = 12 mm, B = 2 mm, and C, and each evaluation was performed.
Test piece c1: C = 0.2 mm
Test piece c2: C = 0.3 mm
Test piece c3: C = 0.4 mm
Test piece c4: C = 0.6 mm
Test piece c5: C = 0.8 mm
Next, test pieces were prepared under the following conditions: test pieces d1, d2, d3, d4, and d = A = 12 mm, B = 6 mm, and C, and each evaluation was performed.
Test piece d1: C = 0.2 mm
Test piece d2: C = 0.3 mm
Test piece d3: C = 0.4 mm
Test piece d4: C = 0.6 mm
Test piece d5: C = 0.8 mm

Table 3 shows the evaluation results when B = 2 mm. Moreover, the measurement result of long-term stability is shown in FIG. The test piece c1 having C = 0.2 mm has a very small amount of extrusion until the screen mesh is clogged, and the productivity is poor. Further, although the amount of foreign matter mixed is small, the fiber filler is broken, so that the Izod impact strength and rigidity are lowered. The test piece c5 of C = 0.8 mm has good productivity, but has a large amount of foreign matter remaining, and the elongation and Izod impact strength are reduced. In test pieces c2, c3, and c4 having screen openings C of 0.3 mm, 0.4 mm, and 0.6 mm in the heat molding machine, the balance between the amount of foreign matter mixed in and productivity is good, and the physical properties are also excellent. I understand that.

  FIG. 4 is a measurement result of long-term stability when B = 2 mm, and is a diagram showing the relationship between the aging time of the thermal stability test and the physical property retention ratio of the bending strength of each test piece. Referring to FIG. 4, it can be seen that the test pieces c1, c2, c3, and c4 having a small amount of foreign matter show long-term thermal stability. This means that with the same amount of antioxidant added, the smaller the foreign matter, the longer the thermal stability time of the regenerated molded body. Thereby, the usage-amount of the additive mix | blended with a fiber reinforced plastic waste material can be suppressed, and it leads to the cost reduction of a recycled molded object.

Table 4 shows the evaluation results when B = 6 mm. Moreover, the measurement result of long-term stability is shown in FIG. From Table 4, as in the case of B = 2 mm, in the test pieces d2, d3, d4 where the screen opening C of the thermoforming machine is 0.3 mm, 0.4 mm, and 0.6 mm, the amount of foreign matter mixed in and the productivity It can be seen that the balance is excellent and the physical properties are also excellent.

  FIG. 5 is a measurement result of long-term stability when B = 6 mm, and is a diagram showing the relationship between the aging time of the thermal stability test and the physical property retention ratio of the bending strength of each test piece. As in the case of B = 2 mm, it can be seen that the test pieces d1, d2, d3, and d4 having a small amount of foreign matter show long-term thermal stability.

  From these results, the test pieces c2, c3, c4, d2, d3, d4 are preferable, that is, the optimum range of the mesh size C of the screen mesh of the thermoforming machine is 0.3 mm ≦ C ≦ 0.6 mm. It can be expressed by a formula.

  From the above results, in the present invention, it is possible to efficiently remove foreign substances adhering to the fiber reinforced plastic waste material by performing sieving according to the screen mesh of the fine crusher. In addition, by optimizing the mesh size of the screen mesh of the heat molding machine, it is possible to efficiently remove foreign substances and suppress breakage of the fibrous filler. You can get a body. Moreover, the usage-amount of the additive for ensuring long-term stability can be reduced, and it leads also to the cost reduction of a reclaimed molded object.

  In other words, material recycling that uses fiber reinforced plastic waste as the main raw material can provide high-quality recycled molded products that can be applied to a variety of applications, and the recycled molded products are again applied to durable consumer goods such as four home appliances. This contributes to reducing the use of new buried fossil resources and, unlike thermal recycling, leads to the suppression of the generation of greenhouse gases such as carbon dioxide.

  It should be understood that the embodiments and examples disclosed this time are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the present invention, since the opening size of the screen mesh of the heat molding machine is optimized and the breakage of the fibrous filler is suppressed, a regenerated molded body having high characteristics can be obtained from the fiber reinforced plastic waste material.

Claims (4)

A method for recycling fiber reinforced plastic waste,
The fiber reinforced plastic is a thermoplastic resin reinforced with fibers,
A crushing step of crushing the fiber-reinforced plastic waste material into a crushed material using a shearing crushing device having a screen mesh having a mesh size of 10 mm or more and 20 mm or less ,
Using a sieve having an opening size of 0.08 times or more and 0.5 times or less of the opening size of the screen mesh used in the crushing step, and a sieving step of removing foreign matters from the crushed material by sieving;
A heat forming step of heating and melting and extruding the crushed material from which the foreign matter has been removed, and
In the heat molding step, the fiber-reinforced plastic waste material is recycled by using a screen mesh having an opening size of 0.3 mm or more and 0.6 mm or less. The sieving process is the recycling method of a fiber reinforced plastic waste according to claim 1, wherein the specific gravity performs sieved in liquid than the specific gravity of the fiber-reinforced plastic waste. A device for recycling fiber-reinforced plastic waste,
The fiber reinforced plastic is a thermoplastic resin reinforced with fibers,
A shear-type crushing device comprising a screen mesh having an opening size of 10 mm or more and 20 mm or less, crushing the fiber-reinforced plastic waste material into a crushed material,
A sieve for removing foreign matter from the crushed material , having an opening size of 0.08 times or more and 0.5 times or less of the opening size of the screen mesh used in the crushing step ;
A heat molding machine that heat-melts and extrudes the crushed material from which the foreign matter has been removed, and
The thermoforming machine has a screen mesh for removing foreign matter from the crushed material,
The apparatus for recycling a fiber-reinforced plastic waste material, wherein an opening size of a screen mesh of the heat molding machine is 0.3 mm or more and 0.6 mm or less. The apparatus for recycling a fiber-reinforced plastic waste material according to claim 3 , wherein the sieve is a wet sieve having a specific gravity less than that of the fiber-reinforced plastic waste material.