JPH0655539A - Method and apparatus for continuous recycling of synthetic resin waste material with coating film - Google Patents

Abstract

PURPOSE:To provide a method and an apparatus for continuous recycling of a synthetic resin waste material with a coating film without deteriorating strength of the material. CONSTITUTION:A bumper 100 which is one of a synthetic resin waste material with a coating film is ground into at most several mm squares. The ground material is fed a const. amt. a time to a hydrolysis apparatus 130 by means of the first quantitative feeding apparatus 120. The coating applied on the ground material is hydrolyzed with steam to make it low mol.wt. The ground material adhered with the hydrolyzed coating is dried by means of a drying apparatus 140 and is then fed into a melting and kneading apparatus 160 by means of the second quantitative feeding apparatus 150. The coating film is finely granulated by means of the melting and kneading apparatus and is uniformly kneaded into the synthetic resin material and is extruded from an extrusion die. After the extruded resin is cooled, it is cut into a const. length to become pellets, which are recycled as a raw material of a newly formed bumper.

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 a coated resin waste material, and more particularly to a continuous method and apparatus for recycling.

[0002]

2. Description of the Related Art In recent years, it has been required to recycle synthetic resin waste materials from the viewpoint of environmental protection, but it is usual to melt and remold the waste materials. However, in Japan, it is common to apply a thermosetting paint to the surface of a synthetic resin material in order to maintain the aesthetic appearance of the product.

Therefore, even if the waste material is melted, the coating material is not decomposed, and when it is remolded as it is, it is unavoidable that the material strength is deteriorated due to the mixed coating film.
For example, when a bumper is made of a scrap material, the collision resistance in cold regions is lower than that of a new material. If the coating film is removed, the reduction in material strength can be avoided, but it is difficult to remove the coating film.

That is, although the coating film can be mechanically removed by shot blasting or the like, when the shape of the parts is complicated, not only it takes time to remove the coating film, but also it cannot be completely removed. Therefore, it is not suitable for mass processing. It has also been proposed to strip the coating with organic salts, but the use of organic salts cannot overcome the environmental problems.

In order to solve the above-mentioned problems, the present applicant has proposed a method of melting and kneading a synthetic resin waste material with a coating after hydrolysis treatment without removing the coating film and reusing it (Japanese Patent Application No. 2000-242242). Flat 3
-192431).

[0006]

However, in order to shorten the treatment time, it is necessary to carry out hydrolysis in a relatively high temperature atmosphere of 180 ° C. for a short time, but avoid melting of the synthetic resin. It is not possible. Therefore, when the synthetic resin is taken out from the reaction vessel after completion of hydrolysis and once cooled, the synthetic resin is solidified and must be crushed when it is reused, which makes continuous treatment difficult.

When the post-process is carried out in the molten state, it is necessary to keep the synthetic resin channel in a predetermined atmosphere, which is against the social demand for energy saving. The present invention has been made in view of the above problems, and an object of the present invention is to provide a method and an apparatus for continuously recycling a coated synthetic resin waste material without deteriorating the material strength.

[0008]

A method for continuously regenerating a coated synthetic resin waste material according to a first aspect of the present invention is obtained by a pulverizing step of pulverizing a coated synthetic resin waste material into a pulverized material, and a pulverizing step. A first fixed-quantity feeding step for continuously and quantitatively feeding the crushed material, and a coating film on the crushed material supplied from the first fixed-quantity feeding step at a predetermined temperature and in a hydrolysis tank equipped with a screw blade. Hydrolysis step of continuously hydrolyzing with pressure steam, drying step of drying the pulverized material with the coating film hydrolyzed in the hydrolysis step, pulverized material with the coating film dried in the drying step Quantitatively feeding continuously and quantitatively, a melt-kneading step of melting and kneading the pulverized material having the coating film supplied from the second constant-quantity feeding step to obtain a kneading material, and a melt-kneading step Kneaded material discharged from Pellets material manufacturing process of the pellets cut to cool after a predetermined length, consisting of.

According to a second aspect of the present invention, there is provided a continuous recycling apparatus for a coated synthetic resin waste material, which comprises: a pulverizing apparatus for pulverizing a coated synthetic resin waste material into a pulverized material; and a pulverized material obtained from the pulverizing apparatus, A first quantitative feeding device for quantitatively feeding, and a first
The continuous hydrolysis device that continuously hydrolyzes the coating film on the pulverized material supplied from the fixed-quantity sending device by steam at a predetermined temperature and pressure, and the pulverization with the coating film hydrolyzed by the hydrolysis device attached. A drying device for drying the material, a second quantitative feeding device for continuously and quantitatively feeding the pulverized material with the coating film dried by the drying device, and a pulverizing material supplied from the second quantitative feeding device. A kneading device for kneading into a kneading material, and a pellet material manufacturing device for cutting the kneading material discharged from the kneading device into pellets by cooling the kneading material into a predetermined length, and the continuous hydrolysis device is crushed. A cylindrical hydrolysis tank casing having a material supply port, a crushed material discharge port, a steam supply port and a steam discharge port, and a crushed material supplied from the crushed material supply port in the hydrolysis tank casing to the crushed material discharge port. Carry Clew blades, upstream seal connected to the grinding material supply port to maintain the temperature and pressure inside the hydrolysis tank casing, and rotary feeder, and downstream seal connected to the grinding material discharge port to maintain temperature and pressure inside the hydrolysis tank casing. It consists of a rotary feeder.

According to a third aspect of the present invention, there is provided a continuous recycling device for a coated synthetic resin waste material, which comprises a crushing device for crushing a coated synthetic resin waste material to a crushed material, and a crushed material obtained from the crushing device in a continuous manner. A first fixed quantity sending device for sending fixed quantity and a first
The continuous hydrolysis device that continuously hydrolyzes the coating film on the pulverized material supplied from the fixed-quantity sending device by steam at a predetermined temperature and pressure, and the pulverization with the coating film hydrolyzed by the hydrolysis device attached. A kneading material by kneading a drying device for drying the material, a second constant-quantity sending device for continuously and quantitatively sending the crushed material dried by the drying device, and a crushing material supplied from the second constant-quantity sending device And a kneading device,
The kneaded material discharged from the kneading apparatus is cooled and cut into a predetermined length to form pellets, and a pellet material manufacturing apparatus is provided, and a continuous hydrolysis device is provided with a pulverized material supply port, a pulverized material discharge port, and a steam supply. A cylindrical hydrolysis tank casing having a mouth and a steam outlet, screw blades for conveying the crushed material supplied from the crushed material supply port into the hydrolysis tank casing to the crushed material discharge port, and the crushed material supply port It consists of an upstream seal rotary feeder that is connected and holds the temperature and pressure inside the hydrolysis tank casing, and a downstream seal rotary feeder that is connected to the pulverized material discharge port and holds the temperature and pressure inside the hydrolysis tank casing. The device
It is a drying device that dries the pulverized material with the steam that has been dehumidified and dried by a steam dehumidifying and drying device for dehumidifying the steam discharged from the steam discharge port of the hydrolysis tank.

[0011]

According to the continuous recycling method for a coated synthetic resin waste material according to the first invention and the continuous recycling apparatus for a coated synthetic resin waste material according to the second invention, the treatment of the coated synthetic resin waste material is as follows. Is done. (1) The coated synthetic resin waste material is roughly pulverized into a rod shape having a predetermined length, and then finely pulverized to 5 mm square or less. The synthetic resin waste material is pulverized with the coating film attached.

(2) The pulverized material is collected by a cyclone, sent to a stock bin by a rotary feeder, continuously metered by a screw feeder, and sent out. (3) The water vapor and the pulverized material are mixed in the hydrolyzing device, and the coating film attached to the pulverized material is hydrolyzed to have a low molecular weight. (4) A drying process is performed to remove water contained in the pulverized material to which the hydrolyzed coating film is attached.

(5) The dried pulverized material is collected by a cyclone, sent to a stock bin by a rotary feeder, continuously metered by a screw feeder, and sent out. (6) After melt-kneading a crushed material and kneading the low molecular weight coating film into a synthetic resin as coating particles having a predetermined diameter or less,
Extrude from the extrusion die. (7) After cooling the kneaded material extruded from the extrusion die,
Cut into a certain length to make pellets.

In the third invention, the steam used for hydrolysis is dehumidified and dried to be used for drying the hydrolysis material.

[0015]

Embodiment FIG. 1 is a flow sheet of an embodiment of a continuous recycling apparatus for a coated synthetic resin waste material according to the second invention. The coated resin waste material is, for example, a polypropylene (hereinafter referred to as PP) bumper 100, the surface of which is coated with polyester / melamine or acrylic / melamine paint.

If the synthetic resin is a thermoplastic resin, P
It is not limited to P and may be modified polypropylene, polyethylene, ABS resin, AS resin, polyamide resin, polyester resin, polycarbonate resin, polyacetal resin, polyphenylene oxide or modified polyphenylene oxide. The coating material to be applied may be a urethane-based or amino resin-based coating material that is hydrolyzed to have a low molecular weight.

The crushing device 110 is composed of a coarse crusher 111 and a fine crusher 112. The bumper 100 is, for example, 30 cm in length and 30 cm in width by the coarse crusher 111 with the coating film on the surface. The crushed material is crushed into a rod shape having a predetermined length of 5 mm and a thickness of 5 mm, and then crushed by the fine crusher 112 to be a crushed material of about 5 mm square or less.

This crushed material is supplied to the first fixed amount feeding device 1
20. The constant-volume delivery device is a suction fan 1.
2a, transport pipe 12b, cyclone 12c, rotary feeder 12d, stock bin 12e, feed screw 12f
And 12 g of the constant-volume feeding screw. That is, the pulverized material is sucked by the suction fan 12a and is transported to the cyclone 12c in the transport pipe 12b. The crushed material transportation means may be a belt conveyor.

The crushed material stored in the cyclone 12c is
The pulverized material stock bin 12e is discharged by the rotary feeder 12d installed at the bottom of the cyclone 12c. The crushed material transferred to the crushed material stock bin 12e is
It is transferred to one side by a feed screw 12f installed at the bottom of the crushed material stock bin 12e, and is fed to the hydrolysis device 130 by a fixed amount by a fixed amount feed screw 12g.

FIG. 2 is a sectional view of the hydrolysis device 130, which comprises an upstream seal rotary feeder 131, a hydrolysis tank 132 and a downstream seal rotary feeder 133. The upstream seal rotary feeder 131 and the downstream seal rotary feeder 133 have the same structure and are composed of a cylindrical casing 13a and a rotor 13b having a recess.

In the rotary feeder, the pulverized material supplied from the supply port provided in the upper portion of the casing 13a is quantitatively supplied to the discharge port provided in the lower portion of the casing 13a by the recess provided in the rotor 13b driven by the motor. Be transported to. That is, by adjusting the rotation speed of the rotor, the amount of pulverized material supplied to the hydrolysis tank or discharged from the hydrolysis tank can be adjusted.

The rotor 13b is assembled so as to be in contact with the casing 13a, and the first fixed-quantity delivery device 120 in which the high temperature and high pressure atmosphere in the hydrolysis tank 132 is upstream.
And leakage to the downstream drying device 140 is prevented. The hydrolysis tank 132 is a device for hydrolyzing the pulverized material, and a hollow rotating shaft 13d is installed along the axis of the cylindrical casing 13c.

A screw blade 1 is provided around the rotary shaft 13d.
3e is installed, and when the rotating shaft 13d is rotated by a motor (not shown), the pulverized material supplied from the material supply port 13f is transferred to the material discharge port 13g. Rotating shaft 13d
A plurality of steam outlets are opened in the periphery of the steam generator. The steam supplied from the steam supply port 13h through the hollow rotary shaft 13d is discharged, and the pulverized material is transferred from the material supply port 13f to the material discharge port 13g. During that time, the coating material applied to the pulverized material is continuously hydrolyzed to lower the molecular weight.

A vapor pool chamber 13 is provided at both ends of the pressure decomposition tank.
k is provided, and they are communicated with each other via a flow path in the rotating shaft 13d and are maintained at the same pressure. Therefore, generation of axial thrust due to steam on the rotating shaft 13d is prevented, and the thrust bearing can be simplified. The atmospheric conditions for the hydrolysis are not particularly limited, but in order to shorten the hydrolysis time and facilitate the handling after hydrolysis, it is possible to set the temperature as high as possible within the range in which the crushed synthetic resin does not melt. desirable. This is because if the synthetic resin material is melted, the crushed material cannot be transferred by the screw blade 13e.

160 ° C. when the synthetic resin is PP
It is suitable to perform the hydrolysis treatment for 0.5 to 2 hours in the atmosphere. A decomposition accelerator such as acid or alkali may be injected together with the steam. That is, the pulverized material after hydrolysis is such that the hydrolyzed pulverized coating material adheres to the entire periphery of the PP material of about 5 mm square.

The temperature and pressure in the hydrolysis tank 132 are
It is controlled by a relief valve 13j connected to the steam outlet 13i. The pulverized material transferred to the discharge port 13g is conveyed by the recess of the rotor 13d of the downstream seal rotary feeder 133 and supplied to the drying device 140. The drying device 140 includes a drying furnace 141, a rotary feeder 142, a bag filter 143, and a suction fan 1.
And 44.

A hot air generating furnace (not shown) is used in the drying furnace 141.
A few% (wt%) of hydrolyzed material due to the hot air generated in
The contained water is removed to 0.1% or less. The air containing water is sucked by the suction fan 144 and released into the air. The fine powder of the coating film hydrolyzed by the bag filter 143 and the fine powdered synthetic resin waste may be removed before being released into the atmosphere.

It is also possible to use superheated steam instead of hot air as energy for drying the drying furnace 141. In this case, the steam discharged from the relief valve 13j and dehumidified and superheated by the steam dehumidifying superheater 180 is dried in the drying furnace 141.
By supplying the hot air generating furnace, it is possible to omit the hot air generating furnace and achieve energy saving.

The hydrolyzed material accumulated at the bottom of the drying furnace 141 is discharged by the rotary feeder 142 and supplied to the second fixed amount feeding device 150. The second fixed amount delivery device 150, like the first fixed amount delivery device 120, includes a suction fan 15a, a transport pipe 15b, and a cyclone 15.
c, a rotary feeder 15d, a stock bin 15e, a feed screw 15f, and a fixed amount feed screw 15g, and supplies the hydrolyzed material to the melt-kneading device 160.

The melt-kneading device 160 comprises a biaxial kneader 161 and an extrusion die 162. In the twin-screw kneader 161, the hydrolyzed material is melt-kneaded in order to atomize the hydrolyzed coating film into, for example, several tens of micrometers or less and knead it into the resin. The melt-kneaded material has, for example, a diameter of 3
It is extruded from a millimeter extrusion die 162 and supplied to the pellet material manufacturing apparatus 170.

The pellet material manufacturing apparatus 170 is a cooling water tank 1.
71 and a cutting machine 172. Extrusion die 1
The linear material extruded from 62 is cooled and hardened in the cooling water tank 171. After that, it is cut by a cutting machine 172 into a predetermined length of 3 mm, for example, to form a cylindrical pellet material.

This pellet material is used as a raw material in a bumper manufacturing process (not shown), for example. In order to inspect the characteristics of the pellet material as a material, a test piece was manufactured and subjected to an Izod impact test and a low temperature embrittlement temperature evaluation test according to JIS. The hydrolysis conditions are a temperature of 160 ° C. and a pressure of 5.5 Kg / cm ² g for 1 hour.

FIG. 3 is a graph showing the results of the Izod impact test, in which the abscissa axis represents the content (weight ratio) of the recycled material contained in the test piece, and the ordinate axis represents the recycled material against the impact strength of the new material. The Izod impact strength retention rate, which is the ratio of the impact strength of the test piece, is taken. The solid line shows the test result at the atmospheric temperature of 23 ° C, and the broken line shows the test result at the atmospheric temperature of -30 ° C.

As can be seen from this graph, the Izod impact strength is maintained irrespective of the content of the recycled material, and the material strength is not lost even if the product is manufactured only with the recycled material. Figure 4
Is a graph showing low-temperature brittleness test results, in which the horizontal axis represents the content (weight ratio) of the recycled material contained in the test piece, and the vertical axis represents the brittleness of the test piece containing the recycled material with respect to the embrittlement temperature of the new material. The embrittlement temperature retention rate, which is the ratio of embrittlement temperature, is taken.

As can be seen from this graph, the embrittlement temperature does not decrease regardless of the content of the recycled material, and the brittleness temperature does not change even if a product is manufactured using only the recycled material. In addition, elongation at break, tensile strength, flexural strength, flexural modulus, hardness and M of recycled materials
Regarding the I value, the same value as the new material was obtained.

[0036]

According to the continuous recycling method for a coated synthetic resin waste material according to the first invention and the continuous recycling apparatus for a coated synthetic resin waste material according to the first invention, the surface of the synthetic resin waste material is coated. The thermosetting coating material can be continuously hydrolyzed without being mechanically removed to be recycled as a recycled material having a material strength equivalent to that of the new material.

According to the continuous recycling apparatus for coated synthetic resin waste material according to the third aspect of the present invention, the steam used for hydrolysis is used for drying the hydrolysis material, and energy can be saved.

[Brief description of drawings]

FIG. 1 is a flow sheet of an example.

FIG. 2 is a sectional view of a hydrolysis device.

FIG. 3 is a graph showing the results of an Izod impact test.

FIG. 4 is a graph showing the results of a low temperature embrittlement temperature evaluation test.

[Explanation of symbols]

 110 ... Crushing device 120 ... 1st fixed amount sending device 130 ... Hydrolysis device 140 ... Drying device 150 ... 2nd fixed amount sending device 160 ... Melt-kneading device 170 ... Pellet material manufacturing device 180 ... Dehumidification heating device

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B29K 105: 26

Claims (3)

[Claims] 1. A crushing step of crushing a coated resin waste material into a crushed material, a first quantitative feeding step of continuously and quantitatively feeding the crushed material obtained in the crushing step, and a first fixed amount. A hydrolysis process in which the coating film on the pulverized material supplied from the sending process is continuously hydrolyzed by steam at a predetermined temperature and pressure in a hydrolysis tank equipped with a screw blade, and is hydrolyzed in the hydrolysis process. It is supplied from the drying process of drying the pulverized material to which the coating film adheres, the second quantitative feeding process of continuously and quantitatively feeding the hydrolyzed material dried in the drying process, and the second quantitative feeding process. A melt-kneading step of melting and kneading a pulverized material with a coating film to form a kneading material, and a pellet material manufacturing step of cooling the kneading material discharged from the melt-kneading step into pellets by cutting into a predetermined length, A coating consisting of Method for continuous recycling of waste synthetic resin. 2. A crushing device for crushing a coated resin waste material into a crushed material, a first fixed amount sending device for continuously measuring and sending the crushed material obtained from the crushing device, and a first fixed amount. A continuous hydrolysis device that continuously hydrolyzes the coating film on the pulverized material supplied from the sending device by steam at a predetermined temperature and pressure, and a pulverized material with the coating film hydrolyzed by the hydrolysis device attached. A kneading material is obtained by kneading a drying device for drying, a second fixed amount feeding device for continuously and quantitatively feeding the pulverized material dried by the drying device, and a pulverized material supplied from the second fixed amount feeding device. A continuous recycling device for a coated resin waste material, which comprises a kneading device and a pellet material manufacturing device that cools the kneading material discharged from the kneading device and cuts it into pellets to a predetermined length. Decomposing device is powder A cylindrical hydrolysis tank casing equipped with a material supply port, a crushed material discharge port, a steam supply port and a steam discharge port, and the crushed material supplied from the crushed material supply port in the hydrolysis tank casing to the crushed material discharge port. A screw blade to carry, an upstream seal rotary feeder connected to the grinding material supply port to maintain the temperature and pressure inside the hydrolysis tank casing, and an upstream seal rotary feeder connected to the grinding material discharge port to maintain the temperature and pressure inside the hydrolysis tank casing. A continuous recycling device for coated synthetic resin waste, consisting of a downstream seal rotary feeder. 3. A crushing device for crushing a coated resin waste material into a crushed material, a first quantitative feeding device for continuously quantitatively feeding the crushed material obtained from the crushing device, and a first quantitative amount. A continuous hydrolysis device that continuously hydrolyzes the coating film on the pulverized material supplied from the sending device by steam at a predetermined temperature and pressure, and a pulverized material with the coating film hydrolyzed by the hydrolysis device attached. A kneading material is obtained by kneading a drying device for drying, a second fixed amount feeding device for continuously and quantitatively feeding the pulverized material dried by the drying device, and a pulverized material supplied from the second fixed amount feeding device. A continuous recycling device for a coated resin waste material, which comprises a kneading device and a pellet material manufacturing device that cools the kneading material discharged from the kneading device and cuts it into pellets to a predetermined length. Decomposing device is powder A cylindrical hydrolysis tank casing equipped with a material supply port, a crushed material discharge port, a steam supply port and a steam discharge port, and the crushed material supplied from the crushed material supply port in the hydrolysis tank casing to the crushed material discharge port. A screw blade to carry, an upstream seal rotary feeder connected to the grinding material supply port to maintain the temperature and pressure inside the hydrolysis tank casing, and an upstream seal rotary feeder connected to the grinding material discharge port to maintain the temperature and pressure inside the hydrolysis tank casing. It is composed of a downstream seal rotary feeder and a drying device that dries the pulverized material with the steam that has been dehumidified and dried by the steam dehumidifying and drying device for dehumidifying the steam discharged from the steam discharge port of the hydrolysis tank. A continuous recycling device for coated synthetic resin waste materials.