JP3228598B2 - Method and apparatus for recycling resin parts - Google Patents

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 recycling resin parts, in particular, painted or plated resin parts.

[0002]

2. Description of the Related Art In recent years, recycling of end-of-life vehicles has attracted attention in the field of the automobile industry due to increasing concerns about environmental issues and recycling. In ordinary cars, about 75% of its weight is dismantled and reused as scrap iron and non-ferrous metal.
The remaining about 25% is treated as industrial waste, and this waste contains about 3% by weight of resin parts together with fibers, rubber, etc.
0% is contained.

As shown in FIG. 6, the surface of a resin part such as a bumper generally has a coating w4 formed on a base material w3 of a thermoplastic resin such as a polypropylene resin as shown in FIG. . The type of the resin of the coating film w4 is a thermosetting resin, for example, an amino polyester type, an amino acrylic type, a polyester urethane type, or an acryl urethane type resin. A crosslinked structure is provided by the process. This is because of its strong and dense structure, the coated resin bumper has excellent chemical resistance, heat resistance, scratch resistance, weather resistance and surface gloss.

However, when the bumper is crushed and pelletized to obtain a material, a coating film piece is mixed with the polypropylene material. In the molding process using the polypropylene material mixed with the coating film piece, the coating film piece is melted. This impairs the fluidity of the resin and causes molding defects such as "burn", "weld mark", and "bubbles" in the molded product. Further, the coating film pieces that have emerged on the surface of the molded article have problems such as impairing the appearance of the product.

[0005] Further, since there is almost no interaction between the coated film piece and the polypropylene resin serving as the base range, the coated film piece becomes rather a "foreign substance" and deteriorates the mechanical properties of the molded article. For example, the impact strength of a recycled polypropylene material mixed with a coating film piece is about 80% of that of virgin polypropylene.

For this reason, it is necessary to remove the coating when recycling the coated resin parts.

[0007] As a method of removing a coating film, there is a method disclosed in Automotive Technology Vol. 46. No5,1
992. It is classified into mechanical, physical and chemical methods as disclosed on pages 3-9.

[0008] The mechanical coating film removing method is, for example, a shot blast method in which an abrasive is sprayed on the coating film using compressed air to remove the coating film, or a coated resin component is roughly pulverized and then finely pulverized. There is a screen mesh method or the like in which a coating film piece mixed without being melted by filtering through a mesh under heating and melting is removed.

The shot blasting method is excellent in toxicity and environmental safety because the coating film is removed by friction, impact, etc., but requires a large amount of processing time, and the coating film removing efficiency is not sufficient. Processing is difficult. The screen mesh method is also excellent in toxicity and environmental safety because the coating film pieces are removed by filtration, but has disadvantages such as a long processing time and insufficient coating film removal efficiency.

[0010] The physical coating film removing method uses a halogen-based solvent or various organic solvents, and removes the coating film by utilizing the solvent permeation into the interface between the coating film and the substrate and the swelling phenomenon of the coating film by the solvent. This is inferior in environmental safety, the coating film removal efficiency and the processing ability are relatively low, and there is a possibility that the substrate may be deteriorated.

[0011] Since these mechanical and physical coating film removal methods have low coating film removal efficiency, molded articles using the same have low appearance and mechanical properties of products, and their application range is greatly limited.

As a method of chemically removing the coating film, for example, there is an organic salt method in which the coating film is chemically decomposed and removed by cutting an ether bond near a crosslinking point of the coating resin with a mixed solution of ethanol and water containing an organic salt. .

This method has problems in secondary treatment such as wastewater treatment, and has problems such as low treatment efficiency and inefficiency. Further, even a plated resin product has problems such as difficulty in removing the plated layer from its efficiency, processing ability, and obtaining high quality recycled resin parts.

[0014]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a high quality recycled resin part which is excellent in the efficiency of removing a coating film or a plating layer, environmental safety and processing ability. To provide a recycling method and apparatus.

[0015]

According to the present invention, there is provided a method for recycling a resin part, comprising the steps of: crushing a coated or plated resin part to obtain a coarse crushed material; A blow step of obtaining a tubular blown material in which a coating piece or a plated piece is mixed into a base resin by an inflation method, and a rolling and stretching step of rolling and stretching the blown material to obtain a film-shaped rolled material,
The method has a fine pulverizing step of pulverizing the rolled material to obtain a finely pulverized material, and a separating step of separating the finely pulverized material into a base resin constituent part and a coating film piece or a plating piece constituent part. Also, a resin component recycling apparatus according to the present invention includes a coarse crushing apparatus for crushing a coated or plated resin part to obtain a coarse crushed material, and a coating film piece or a plating piece on the base resin by the inflation method. A blow device for obtaining a tube-shaped blown material mixed with, a rolling and stretching device for rolling and stretching the blown material to obtain a film-shaped rolled material, and a fine crushing device for crushing the rolled material to obtain a finely crushed material And a separation device for separating the finely pulverized material into a base resin component and a coating film piece or a plating piece component.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and an apparatus for recycling resin parts according to the present invention will be described by taking as an example a case where a coated resin bumper, which is a large part among automobile resin parts, is collected and recycled.

FIG. 1 is a schematic explanatory view of a method and an apparatus for recycling resin parts in this embodiment, and FIG. 2 is a flowchart showing each step.

In the figure, w is removed from a scrapped vehicle and collected.
It is a coated resin bumper with a metal part removed, and on a thermoplastic base material such as polypropylene resin, amino polyester type, amino acrylic type, polyester urethane type,
The coating film is formed of a thermosetting resin such as an acrylic urethane resin.

Reference numeral 1 in the drawing denotes a coarse crushing device such as a cutter mill having a screen of about 4 mm for crushing the coated resin bumper w to obtain a coarsely crushed material wa.

The coarsely crushed material wa obtained by the coarse crushing device 1 is supplied to a hopper 2 a of a blow device 2. Blow device 2
Is a device for obtaining a tube-shaped blown material wb by an inflation method, wherein a coarsely crushed material wa put into a hopper 2a is advanced in a barrel 2c by rotation of a screw 2b, and is heated by a band heater or the like. While being advanced in the inside, the thin-walled tube is extruded from the inflation die 2d such as a crosshead die and the like, and the upper end is pinched by the pinch roll 2e. 2e, the tube-shaped blow material w
b.

Downstream of the blow device 2, the blow device 2
A rolling and stretching apparatus 3 is provided for rolling and stretching a blown material wb in which a thermosetting resin coating film piece is mixed into a thermoplastic resin base resin manufactured by the method described above. The rolling and stretching device 3 includes a pair of upstream rollers 3a provided on the upstream side, and a pair of downstream rollers 3b provided on the downstream side and driven to rotate at a peripheral speed greater than the peripheral speed of the upstream roller 3a. A heating means 3c is provided between the upstream roller 3a and the downstream roller 3b, and the blow material wb manufactured by the blowing device 2 is provided between the upstream roller 3a and the downstream roller 3b. The resin is configured to be heated to a temperature at which the resin is plasticized, stretched, and rolled to obtain a film-shaped rolled material wc.

Reference numeral 4 in the drawing denotes a fine pulverizing device for pulverizing the rolled material wc produced by the rolling and stretching device 3 to obtain a finely pulverized material wd. The finely pulverized material wd obtained by the fine pulverizing device 4 is pin milled. And a portion wf forming a coating film by a separation device 5 such as a centrifugal separator or a specific gravity separator. The finely pulverized material excluding the coating film forming portion is heated and melted into pellets we. Is manufactured, and a resin product such as a bumper is obtained again.

Next, a method of recycling a resin component using the resin component recycling apparatus thus configured will be described with reference to the flowchart of FIG.

The collected resin bumper w from which the metal portion has been removed is pulverized by a coarse pulverizing device 1 such as a cutter mill in a coarse pulverizing step 1s to become a coarse pulverized material wa. The coarsely crushed material wa has a base material made of a thermoplastic resin, that is, a base resin w1 as shown in FIG.
Is coated with a coating film piece w2 made of a thermosetting resin.

Coarse crushed material wa crushed in the coarse crushing step 1s
Is supplied to the hopper 2a of the blowing device 2 in the next blowing step 2s, and the coarsely crushed material wa supplied to the hopper 2a
Is heated as the screw 2b rotates, and the barrel 2c is heated.
The softening and mixing is performed during the forward movement of the inside, and the fluidized state is obtained.
Is extruded into a thin tube shape, and is expanded by a predetermined amount by the air fed into the tube to form a tube-shaped blow material wb which is stretched.

The surrounding film wh inflated into a balloon shape by the blowing device 2 has a relatively large size on the base resin w1 as shown in the plan view of FIG. The coating film pieces w2 of the dimensions are mixed.

The blown material wb thinly stretched in advance in the blowing step 2s is further rolled and stretched by the rolling stretching apparatus 3 in the subsequent rolling and stretching step 3s.

[0028] That is, blanking brazing material wb, which is stretching the tubular by blow device 2 is respectively rolled by the upstream roller 3a and the downstream rollers 3b of the rolling stretch apparatus 3, and the base resin w1 by the heating means 3c It is heated to a temperature equal to or lower than the melting point and plasticized, and is further stretched in the flow direction between the upstream roller 3a and the downstream roller 3b in accordance with the difference in peripheral speed between the upstream roller 3a and the downstream roller 3b. You.

The extruded material wb at the downstream position 3d of the upstream roller 3a is, as shown in the plan view of FIG. 4B and the sectional view taken along the line bb of FIG. The coating film pieces w2 mixed in the base resin w1 are crushed and pulverized. Furthermore, since the base resin w1 is a thermoplastic resin, it is softened by heating, becomes fluid, and is easily stretched, whereas the coating film piece w2 is not stretched because it is a thermosetting resin. Therefore, the coating film piece w with respect to the elongation of the base resin w1.
No. 2 cannot follow, cracks or cracks are easily generated between them, and separation becomes easy.

The strength of the base resin w1 in the direction perpendicular to the stretching direction is reduced by stretching, and the base resin w1 is easily torn.

The extruded material wb stretched between the upstream roller 3a and the downstream roller 3b is rolled by the downstream roller 3b, and the coating film w2 mixed into the base resin w1.
Is crushed to form a film-shaped stretched material wc which is further finely pulverized as shown in a plan view in FIG. 4C and a cross-sectional view in FIG.

The film-shaped stretched material wc composed of the base resin w1 including the finely pulverized coating film pieces w2 is subjected to a fine pulverizing device 4 in the next fine pulverizing step 4s by, for example, about 20 mm in diameter.
Finely pulverized to about 30 μm. In the fine pulverization, the coating film piece w2 is finely divided in advance in the rolling and stretching step 3s, and a crack is easily generated or torn between the base resin w1 and the coating film piece w2, and the strength of the base resin w1 is further reduced. Since the base material w1 and the coating film piece w2 are not bonded to each other because they are easily torn, a finely pulverized material wd in a state in which a so-called finely ground material of the base resin w1 and a finely ground material of the coating film piece w2 are mixed is obtained. It is obtained very efficiently.

Finely pulverized material obtained in the finely pulverizing step 4swd
In the next separation step 5s, a pin mill, specific gravity separator, etc.
Constitutes the base material of the bumper w.
The constituent parts of the base resin w1 and the coating that constituted the coating film
It is separated into constituent parts wf of the film piece w2. Before separation
In the fine grinding step 4s, the base resin w1 and the coating film piece w2
Finely ground material without bondingwdIs very good because
It can be separated into

From the finely pulverized material wd from which the constituent parts wf of the coating film piece w2 are separated and removed, in the next pelletizing step 6s, a high-purity pellet WE containing almost no coating film piece w2 is obtained. A recycled product wg is obtained by the commercialization process 7s.

In the recycled product wg, since the coating film pieces w2 are sufficiently separated and the produced pellets we are used as a raw material, molding defects such as "weld marks" and "bubbles" and appearance are not impaired. Further, a high quality product comparable to a product made of a virgin material having excellent impact strength without loss in mechanical properties is possible.

In the above embodiment, the extruded material wb extruded from the extruder 2 by one rolling and stretching device 3 is rolled and stretched to obtain a film-shaped rolled material wc. It is also possible to provide a rolled material wc by repeating the rolling and stretching of the extruded material wb an appropriate number of times.

FIG. 5 is a schematic explanatory view showing another embodiment of a method and an apparatus for recycling resin parts according to the present invention. In FIG. 5, parts corresponding to those in FIG. Although not shown, reference numeral 6 in the figure denotes a rolling and stretching apparatus for rolling and stretching the blown material wb formed into a tube shape by the blowing device 2 to obtain a film-shaped rolled material wc.

This rolling and stretching apparatus 6 performs a rolling and stretching step 3s.
And a pair of upstream rollers 6 provided on the upstream side
a, a downstream roller 6b provided on the downstream side, and a cooling means 6c disposed between the upstream roller 6a and the downstream roller 6b, and having a peripheral speed higher than the peripheral speed of the downstream roller 6b. It is configured to be driven to rotate at a speed.

The operation of the rolling and stretching apparatus 6 is such that the blown material wb formed into a tube in the blowing step 2s is rolled by the upstream roller 6a to crush the coating film piece w2, and the cooling means 6c is used to crush the coating film piece w2. Cooling to below the embrittlement temperature of w2 causes brittle fracture of the coating film piece w2. Further upstream roller 6a
Of the extruded material wb
Is stretched, and cracks are easily generated or generated between the base resin w1 and the coating film pieces w2. The extruded material wb stretched in this manner is rolled by the downstream roller 6b, and the coating film piece w2 mixed into the base resin w1 is finely crushed to form a film-shaped stretched material wc.

When the stretched material wc is pulverized by the pulverizing device 4 in the next pulverizing step 4s, the coating film piece w2 is broken in advance in the rolling and stretching step 3s, and the base resin w1 and the coating resin piece w A crack is easily generated or torn at the joint portion of w2, and further, the base resin w1 is easily torn, so that a finely pulverized material wd in which the coating film piece w2 does not adhere to the base resin w1 can be obtained very efficiently. As a result, the fractionation in the fine separation step 5s is improved, and the production of a high-quality recycled product wg becomes possible as in the above embodiment.

In this embodiment, similarly to the above embodiment, a plurality of rolling and stretching devices 6 can be provided so that rolling and stretching of the blown material wb are repeated several times as appropriate to obtain a rolled material wc. is there.

In the above-described embodiment, the blow material wb is heated or cooled in the rolling and stretching step 3s. However, by omitting the heating or cooling, the apparatus and control can be simplified.

Further, the rolled material wc obtained in the rolling and stretching step 3s
Without immediately grinding in the fine grinding step 4s,
By storing c in a roll form and storing it as a material in a roll state or in a stacked state, it is possible to reduce the storage volume as compared with storing in a crushed material state or a pellet state. In this case, the storage volume can be reduced to 1/2 to 1/3 as compared with storage in a crushed state.

In the above description, the case where the coated resin bumper is collected and recycled has been described. However, the present invention is not limited to this, and a resin product in which a thermosetting resin is coated on another thermoplastic resin, or a plating process is performed. It is possible to recycle even the applied resin product by the same method or apparatus.

More specifically, in the coarse pulverizing step, a coarsely pulverized material is produced by coarsely pulverizing the plated resin component in a coarse pulverizing step, and the coarsely pulverized material is blown in a blowing step 2s.
As a result, a blown material in which plated pieces are mixed in the base resin by the inflation method is obtained. Next, the blown material is rolled and stretched into a film shape by the rolling and stretching device 3 or 6 in the rolling and stretching step 3s.
In s, a finely pulverized material is obtained by the finely pulverizing device 4. The pulverized material is removed from the finely pulverized material by the separation device 5 in the separation step 5, and pelletized in the pelletization step 6s, and a recycled product can be obtained in the product step 7s.

[0046]

According to the method and apparatus for recycling resin parts described above, the coated or plated resin parts are roughly pulverized, and the coarsely pulverized material is previously blown into a thin tube-shaped blow material by a blower. Then, the blown material is rolled and stretched to crush the coated film or plated piece to make it finer and to promote separation between the base resin and the coated film or plated piece, so that the next fine pulverization can be easily performed. And a finely pulverized material having no bonding between the base resin and the coating or plating piece is obtained, and it is possible to obtain a high-quality recycled resin part having extremely high removal efficiency of the coating or plating layer, and Compared with the conventional methods of removing each coating or plating layer, there is no need to use a solvent or the like, so it has excellent effects such as toxicity, excellent environmental safety, and excellent processing ability. Me In which large made to contribute to the recycling of plastic parts subjected it is.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of a method and an apparatus for recycling resin parts according to the present invention.

FIG. 2 is a flowchart showing each step.

FIG. 3 is an explanatory view showing a cross section of a coarsely crushed material obtained by crushing a resin component.

FIG. 4 is an explanatory view showing a state of a coating film piece mixed into a base resin in a rolling and stretching step.

FIG. 5 is a schematic explanatory view showing another embodiment of a method and an apparatus for recycling resin parts according to the present invention.

FIG. 6 is a sectional view of a coated resin bumper.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 Coarse crushing device 2 Blow device 3 Rolling and stretching device 4 Fine crushing device 5 Separation device 6 Rolling and stretching device 1 s Coarse crushing process 2 s Blowing process 3 s Rolling and stretching process 4 s Fine crushing process 5 s Separating process w Painted resin parts (bumper) wa Coarse pulverized material wb Extruded material wc Rolled material wd Finely pulverized material we Pellets wg Recycled product (bumper)

Claims (6)

(57) [Claims] 1. A coarse crushing step of crushing a coated or plated resin part to obtain a coarse crushed material, and a tube-like process in which the coarse crushed material is mixed with a coating resin or plated piece in a base resin by an inflation method. A blowing step of obtaining a blown material, a rolling and stretching step of rolling and stretching the blown material to obtain a film-shaped rolled material, a finely pulverizing step of pulverizing the rolled material to obtain a finely pulverized material, A method of separating resin parts into a base resin constituent part and a coating film piece or a plating piece constituent part. 2. The method of claim 1, wherein the extruded material is heated in the rolling and stretching step to plasticize the base resin. 3. The method according to claim 1, wherein the extruded material is cooled to a temperature equal to or lower than the embrittlement temperature of the coating film piece in the rolling and stretching step. 4. A coarse crushing device for crushing a coated or plated resin part to obtain a coarse crushed material, and a tube-like material in which a coating film piece or a plating piece is mixed into a base resin by the inflation method. A blowing device for obtaining a blown material, a rolling and stretching device for rolling and stretching the blown material to obtain a rolled material in the form of a film, a fine crushing device for crushing the rolled material to obtain a finely crushed material, An apparatus for separating resin parts into a base resin component and a coating film or plating piece component. 5. The apparatus for recycling resin parts according to claim 4, wherein the rolling and stretching apparatus includes heating means for heating the extruded material to plasticize the base resin. 6. The apparatus for recycling resin parts according to claim 4, wherein the rolling and stretching apparatus includes cooling means for cooling the extruded material to a temperature lower than the embrittlement temperature of the coating film piece.