JP2003039432A - Method for regenerating waste synthetic resin pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and inexpensively produce a regenerated article. SOLUTION: A cutting process for producing vinyl chloride resin pipe bodies 2 by cutting a waste vinyl chloride resin pipe 1 for an electric wire in a prescribed length, a heating process for heating/softening the pipe body in a heating chamber 3 to be processed, and a molding process in which the inner hole of the pipe body 2 after being heated and before being hardened is flared while hole flaring bodies 6 are inserted gradually into the pipe body 2 from both end openings so that the pipe body 2 is molded into a joint 10 which is the regenerated article are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recycling synthetic resin pipes such as discarded vinyl chloride pipes (hereinafter referred to as "vinyl chloride pipes").

[0002]

2. Description of the Related Art Recently, due to the social demand for undergrounding of electric wires, electric wire construction has been actively carried out by burying a PVC pipe for electric wires in the ground and passing the electric wire through the PVC pipe. With the pipe connection in this construction, the unnecessary PVC pipes called the PVC pipe cutting pipe and the residual pipe are no longer needed and are discharged as a large amount of waste, which is difficult to process. Incineration of waste PVC pipes causes environmental pollution.Therefore, as a recycling method for environmental protection and resource saving, waste PVC pipes should be crushed with a crusher into granules, and then the crushed material should be used as a raw material in a molding die. It is performed by molding it into a PVC pipe for use as a recycled product.

[0003]

According to the conventional regenerating method, since the reprocessing is performed after returning to the regenerated raw material, the reprocessing is troublesome and expensive, and more energy is consumed for the reprocessing. However, the manufacturing cost of recycled products tends to be high, and there has been a demand for the proposal of a simple recycling method. An object of the present invention is to easily and inexpensively produce a recycled product.

[0004]

A first feature of the present invention is a cutting step of cutting a waste synthetic resin pipe into a predetermined length to produce a plurality of synthetic resin pipe bodies, and the above synthetic resin. Regeneration of the synthetic resin pipe by heating the pipe to heat it and softening it and expanding the inner hole of the synthetic resin pipe from both ends on the opening side while inserting the hole expansion body inside before heating and hardening. And a molding step of molding into a product. The second feature of the present invention is that it comprises a cooling step of cooling the synthetic resin tube after molding the recycled product. A third feature of the present invention is that in the molding step, the diameter of the inner hole gradually increases from the central portion toward the openings at both ends, and a ridge is formed on the inner periphery of the central portion. The fourth feature of the present invention is that the discarded synthetic resin pipe is a underground pipe, for example, a vinyl chloride pipe for underground electric wires. A fifth feature of the present invention is to insert a single cutting line from one end to the other end of the discarded synthetic resin pipe, and then to a predetermined length in the axial direction of the synthetic resin pipe. A cutting step of cutting to make a plurality of synthetic resin tubes, a heating step of heating and softening the synthetic resin tubes, and a lower mold of the molding die for the synthetic resin tubes before heating and curing. Set in the recess of the molding part, hold the cut end that is cut by the cutting line on the outer peripheral part of the synthetic resin tube, and bend it so as to cover the upper side of the projection of the molding part. Molding a synthetic resin pipe body into a recycled product by aligning the upper mold with the lower mold while making the convex part and the concave part of the molding part of the upper mold face the concave parts and the convex parts of the molding part of the lower mold. And a process.
A sixth feature of the present invention is that it has a cooling step of cooling the synthetic resin tube after molding. The seventh feature of the present invention resides in that after molding, a semicircular synthetic resin tube body divided into two is connected to the upper side of the recycled product. An eighth feature of the present invention is that the discarded synthetic resin pipe is a buried underground pipe, for example, a vinyl chloride pipe for a buried underground electric wire.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION With respect to a method for producing a recycled product from a waste synthetic resin pipe according to the present invention, referring to FIGS. 1 to 3, a recycling of a waste PVC pipe 1 for an underground wire to be buried. A method of manufacturing the joint 10 which is a product will be described. First, as shown in FIGS. 1 (A) and 1 (B), a plurality of PVC pipes 2 are manufactured by cutting the PVC pipe 1 into a predetermined length (for example, about 20 cm) in the axial direction. (Cutting process). Next, as shown in FIG. 1C, the vinyl chloride tube body 2 cut into a predetermined length is heated to be softened (heating step). The heating method will be described. In the illustrated example, a plurality of PVC pipes 2 are attached to the roller 4 rotatably arranged in the heating chamber 3.
After passing through, the roller is rotated and driven (not shown).
Rotate at low speed. Since the PVC pipe body 2 also rotates with the rotation of the roller 4, a predetermined temperature (for example, 130 ° C.) is applied to the rotating PVC pipe body 2 from the outer peripheral surface side thereof by a heating means 5 (FIG. 3) such as a heater. ) To uniformly soften the entire PVC pipe body 2 to such an extent that it can be easily processed. Thereafter, as shown in FIGS. 1 (D) and 1 (E), while the PVC pipe body 2 is inserted into the inside from both end opening sides of the PVC pipe body 2 before being cured after heating, the inner hole 2a is gradually expanded to expand the PVC. The tubular body 2 is molded into a recycled product (molding process). The molding method will be described. In the illustrated example, the PVC pipe body 2 is placed on the mounting table 7. Then, while gradually expanding the hole expanding body 6 detachably attached to the holding body 9 by extending the rod 8 of the cylinder that is the driving means from the openings on both sides of the PVC pipe body, it advances toward the central portion of the PVC pipe body. Then, the forward movement is stopped at the substantially central position shown in FIG. The hole expanding body 6 has a larger diameter from the front end to the rear end like a truncated cone, and is set larger than the inner hole 2a of the PVC pipe body 2. For this reason, the hole expanding body 6 is inserted into both side open ends of the PVC pipe body 2,
Gradually push the inner hole 2a outwards, and eventually, as shown in FIG.
At the final stop position shown in, the inner shape of the inner hole is deformed as if it were a drum shape. After the molding, the hole expanding body 6 is retracted and separated from the PVC pipe body 2, thereby completing the joint 10 which is a connection pipe as a recycled product shown in FIG. The overall shape of the joint 10 is a shallow groove 1 which is curved inwardly around the entire center of the outer peripheral surface.
0b is located in the inner hole 10a and faces the groove.
Are formed. Finally, the joint 10 is cooled by a cooling means, and is immersed in, for example, a cooling water tank to be cooled and fixed (cooling step), whereby the production of the recycled product is completed. As a method of using the joint 10, for example, as shown in FIG. 2, discarded PVC pipes 1A and 1A having the same structure as the PVC pipe 1 are used.
When one end of A is inserted into the inner hole 10a from both end openings of the joint and both vinyl chloride pipes 1A, 1A are connected, one PVC pipe which is a recycled product is completed. This recycled product is buried in the ground as a buried pipe P for a buried wire, for example. When connecting the vinyl chloride pipes 1A and 1A, the diameter of the inner hole 10a of the joint 10 gradually increases from the central portion toward the opening end, so that there is an advantage that the coupling between the joint and the vinyl chloride pipe 1A is strengthened. The ridge 10 located at the center of the inner hole 10a
c serves as a stopper for the PVC pipes 1A and 1A entering from both sides, and the stop position becomes accurate.

Since there are several types of PVC pipes 1 (PVC pipes 2) having different inner holes (inner holes 2a of the PVC pipes), a hole expanding body 6 corresponding to these sizes is prepared. .
To replace the hole expanding body 6, the cylindrical hole expanding body 6 is attached / detached to / from the holding portion 9a protruding from the main body of the holding body 9 shown in FIG. 1 (E).

With reference to FIGS. 4 to 8, a lower part 20 which is a recycled product of a PVC pipe 11 for a buried underground electric wire.
A method of manufacturing the nozzle 20 composed of A and the upper base portion 20B will be described. [Manufacturing process of lower stand portion 20A] First, FIGS. 4 (A) and 4 (B)
As shown in, the PVC pipe 11 is provided with a single cutting line 11a extending from one end to the other end in the axial direction, and then the PVC pipe 12 is cut at a predetermined length (for example, about 5 cm) to form the PVC pipe 12. Manufacturing (cutting process). Next, as shown in FIG. 4 (C), the PVC pipe body 12 cut to a predetermined length and having the cutting line 11a cut therein is heated to be softened (heating step). The heating method is the same as the method using the heating chamber 3 shown in FIG. Therefore, since the heating means and the roller have substantially the same configuration as the roller 4 and the heating means 5,
The symbols are the same as above. After heating to soften the entire PVC pipe 12 to an extent that it can be easily processed, FIG.
As shown in (D) and (E), the PVC pipe 12 is set in the concave portion 16a1 in the molding portion of the lower mold 16a of the molding die 16 and is cut by the cutting line 11a before curing after heating. The end portion 12a is held and bent in the direction of the arrow in FIG. 4D so as to cover the upper side of the semicircular convex portion 16a2. The convex portion 16b2 and the concave portion 16b1 of the molding portion of the upper mold 16b are replaced with the concave portion 16a1 of the molding portion of the lower mold 16a.
The upper mold 16b is aligned with the lower mold 16a while facing the convex portion 16a2. Then, the PVC pipe body 12 softened in the forming portion of the forming die 16 is deformed and is formed into a substantially S-shaped recycled product (forming step). After the molding, the recycled product made of the PVC pipe body 12 is released from the molding die 16, and the result is shown in FIG.
The lower part 20A of the nozzle as a recycled product is completed. The overall shape of the lower base portion 20A is substantially S-shaped, and is a substantially semicircular concave groove 20A1 for receiving a pipe which is curved upward to the right.
However, a semi-circular convex portion 20A2 is formed on the left side, and a substantially semi-circular concave groove 20A curved upward is formed below the convex portion.
3 is formed. Finally, the lower base portion 20A is subjected to a cooling treatment by a cooling means, and is immersed in, for example, a cooling water tank to be cooled and fixed (cooling step), thereby completing the production of the lower base portion 20A in the nozzle of the recycled product. [Manufacturing process of the upper base 20B] Similar to the cutting process of the lower base 20A, the vinyl chloride pipe is cut in the axial direction at the same length (for example, about 5 cm) as the cutting length of the lower base 20A, and then the PVC pipe is cut. The body 22 (FIG. 5) is manufactured, and each PVC pipe body is divided into two pieces from the center to create the upper base portion 20B as a recycled product. If necessary, as shown in the figure, the upper base portion 20B
The spacer 20Ba may be produced by horizontally cutting the upper end of the spacer 20Ba. [Assembling Process of Lower Base 20A and Upper Base 20B] FIG.
As shown in, when the spacer 20Ba is provided on the convex portion 20A2 of the lower base portion 20A, the spacer 20B
When the upper base portion 20B is placed via a, the upper base portion is connected to the convex portion by a connecting tool 20C (FIG. 7) such as a screw, so that the nozzle 20 is completed.

With reference to FIGS. 7 and 8, the nozzle 20 is replaced with a buried underground pipe PA for electric wires (specifically, a buried underground pipe P1,
P2, P3, P4, P11, P12, P13) will be described below. In the ground, a plurality of underground buried pipes PA are piped in multiple stages. First, in order to hold the bottommost underground buried pipes P1, P2, P3 and P4, the length of the underground buried pipes PA is different from that of the underground buried pipes. According to the above, the nozzles 20 are arranged at a plurality of locations. As an arrangement method, the recessed groove 20A of the first nozzle 20 is provided in the underground buried pipe P1 which is previously piped.
After being covered with 3, the underground buried pipe P2 is placed in the groove 20A1. Then, as shown in FIG. 7, the position of the second nozzle 2 is shifted to the side of the first nozzle 20 (upward in the drawing) in the longitudinal direction.
0 adjacently installed, and the second nozzle 20 is attached to the underground pipe P2.
After being covered with the groove 20A3, the underground pipe P3 is placed in the groove 20A1. After that, as shown in FIG. 7, the third nozzle 20 is installed adjacent to the side of the second nozzle 20 (upward in the figure) by shifting the position in the longitudinal direction, and the third nozzle 20 is installed in the underground buried pipe P3. After being covered with the groove 20A3 of the nozzle base 20, the underground pipe P4 is placed in the groove 20A1. Hereinafter, the fourth and subsequent nozzles will be installed in the same manner as above. This way
The bottom buried pipes P1, P2, P3, P4, ... Are held by the nozzle 20. After that, the underground buried pipes P11, P12, P13, ... of the second stage are respectively held by the upper pedestal portion 20B of each adjacent nozzle stub 20. Furthermore, the method of arranging the nozzle 20 for holding the underground buried pipe in the third stage is the same as that of the nozzle 20 in the lowermost stage. The second underground buried pipes P11, P12, P13, ... Use the nozzle 20 as a base. In this way, the underground buried pipes PA, which are piped in multiple stages, are held by the nozzle 20. As a matter of course, as the underground buried pipe PA, the underground buried pipe P for the above-mentioned underground buried electric wire which is a recycled product may be used.

The waste synthetic resin pipe is not limited to the underground buried pipe for underground buried electric wire. Further, the nozzle 20 is the lower base 20
You may comprise only A.

[0010]

According to the present invention, since the discarded synthetic resin pipe is reprocessed without destroying its original shape,
Recycled products can be produced easily and at low cost, which also contributes to energy saving.

[Brief description of drawings]

FIG. 1 is a process drawing showing stepwise a method of regenerating a joint which is a regenerated product according to the present invention.

FIG. 2 is a front view showing an example of how to use a joint which is a recycled product.

FIG. 3 is an enlarged cross-sectional view taken along line III-III of FIG.

FIG. 4 is a process chart showing stepwise a method of remanufacturing a lower part of a nozzle that is a remanufactured product according to the present invention.

FIG. 5 is a process drawing showing a method of regenerating the upper part of the nozzle, which is a remanufactured product according to the present invention.

FIG. 6 is a cross-sectional view showing a nozzle that is a recycled product according to the present invention.

FIG. 7 is a plan view showing a usage state of a nozzle that is a recycled product according to the present invention.

FIG. 8 is a front view showing a usage state of a nozzle that is a recycled product according to the present invention.

[Explanation of symbols]

1 PVC pipe (synthetic resin pipe) 2 PVC pipe (synthetic resin pipe) 2a Inner hole 4 Roller 5 Heating means 6 Hole expanding body 10 Joint (recycled product) 10a Inner hole 10c Projection 11 PVC pipe (synthetic resin) Pipe manufacturing 11a Cutting line 12 PVC pipe (synthetic resin pipe body) 12a Cutting end 16 Mold 16a Lower mold 16a1 Mold recess 16a2 Mold convex 16b Upper mold 16b1 Mold recess 16b2 Mold Convex portion 20 Tube base (recycled product) 20A Lower base portion 20A1 Recessed groove 20A2 Convex portion 20A3 Recessed groove 20B Upper base portion 20C Connecting tool 22 PVC pipe body (synthetic resin pipe body) P Underground pipe

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29L 31:24 B29L 31:24

Claims (8)

[Claims] 1. A cutting step of cutting a waste synthetic resin pipe into a predetermined length to produce a plurality of synthetic resin pipe bodies, and a heating step of heating the synthetic resin pipe body to soften it. A molding step of molding the synthetic resin pipe body into a recycled product by expanding the inner hole while inserting the hole expanding body into the inside from both end opening sides of the synthetic resin pipe body before heating and curing. Recycling method for waste plastic tubes. 2. The method for recycling a waste synthetic resin pipe according to claim 1, further comprising a cooling step of cooling the synthetic resin pipe after molding the recycled product. 3. The molding process according to claim 1, wherein the inner hole has a diameter gradually increasing from the central portion toward the openings at both ends and a ridge is formed on the inner periphery of the central portion. Recycling method for waste synthetic resin pipes. 4. The discarded synthetic resin pipe is a vinyl chloride pipe for underground electric wires.
The method for recycling a waste synthetic resin pipe according to claim 2 or 3. 5. A single cutting line extending from one end to the other end of the discarded synthetic resin pipe is inserted, and then cut into a predetermined length in the axial direction of the synthetic resin pipe to make a plurality of cut lines. Of the synthetic resin tube, a heating step of heating the synthetic resin tube to soften it, and a heating step of heating the synthetic resin tube before heating and hardening the synthetic resin tube of the molding part of the lower die of the molding die. Set in the recess, hold the cut end that is cut by the cutting line on the outer peripheral part of the synthetic resin tube, bend it so as to cover the upper side of the convex part of the molding part, and then And a molding step of molding a synthetic resin tubular body into a recycled product by aligning the upper mold with the lower mold while making the convex part and the concave part of the molding part face the concave part and the convex part of the molding part of the lower mold. A method for recycling waste synthetic resin pipes, which is characterized by: 6. The method for recycling a waste synthetic resin pipe according to claim 5, further comprising a cooling step of cooling the synthetic resin pipe body after molding. 7. The method for recycling a waste synthetic resin pipe according to claim 5, wherein after molding, a semicircular synthetic resin pipe body divided into two is connected to the upper side of the recycled product. 8. The discarded synthetic resin pipe is a vinyl chloride pipe for underground electric wires.
The method for recycling a waste synthetic resin pipe according to claim 6 or 7.