JP2003320531A - Method for compressing and reducing volume of waste plastic - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for compressing and reducing volume of waste plastics which can suitably compress and reduce the volume of waste plastic by a high-pressure press machine. <P>SOLUTION: The method for compressing and reducing the volume of the waste plastics comprises the steps of charging and filling the waste plastic in the casing of the press machine, and compressing the plastic by a high- pressure pressing force by a hydraulic cylinder. When the volume of plastics are reduced by compression, the pressing force of the cylinder is slightly reduced, the repulsion force of the compressed and reduced material is weakened, the casing is then opened, and the material is bundled by a bundling material. After the material is bundled, the cylinder is retracted, and the compressed and reduced material is taken out from the casing. <P>COPYRIGHT: (C)2004,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reducing the volume of waste plastic such as used styrofoam and PET bottles, and more particularly, to a method using a press having a high pressing force. The present invention relates to a method for compressing and reducing the volume. 2. Description of the Related Art In recent years, so-called recycling of resource garbage discharged from business establishments and homes as part of environmental protection has been actively carried out. As one of the so-called garbage, there is waste plastic typified by styrene foam and PET bottles. By the way, these waste plastics are generally very bulky, and when they are collected for recycling, they require a large space for storage, and when they are transported, they are inefficient and transport costs are too high. Therefore, conventionally, volume reduction processing has been performed by various methods such as heating and melting processing using a chemical solution. As one of those volume reduction methods, there is a compression volume reduction process using a press machine or the like. In this compression volume reduction processing, first, the collected waste plastic is filled into a casing of a dedicated press machine, and the waste plastic is compressed by a cylinder. The filling and compression operations are repeated a plurality of times until the waste plastic compressed in the casing becomes a lump of an appropriate size. Then, when the compressed waste plastic becomes a lump of appropriate size, the casing is opened while being compressed by the cylinder, the binding material is wound around the waste plastic, bound, and then the cylinder is raised to bind. Take out the used waste plastic and complete the volume reduction process. [0004] Compared with the volume reduction method such as the melting treatment, the compression treatment has a simpler device configuration, allows easy maintenance and can reduce the running cost, and changes the properties of the waste plastic like the melting treatment. Without doing so, it is a convenient reproduction processing method. [0005] In the compression and volume reduction processing of waste plastic, the higher the pressure, the higher the volume reduction rate can be achieved. A strong repulsive force (restoring force) is generated in the waste plastic that has been stored, and particularly in the case of styrofoam or the like, the repulsive force is considerably large. If you attempt to open the casing to bind the compressed volume-reduced material, there is a possibility that air will blow out vigorously from the compressed volume-reduced material, or the door may be suddenly pushed open to disperse the volume-reduced material. Is expected. SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a method for compressing and reducing the volume of waste plastic, which can suitably compress and reduce the volume of waste plastic with a high-pressure press. [0007] In order to solve the above-mentioned problems, the present invention is a method for compressing and reducing the volume of waste plastic such as used polystyrene foam or PET bottles using a high-pressure press machine. A step of charging the waste plastic in the casing of the press machine and filling the same, and a step of compressing the waste plastic filled in the casing with a cylinder,
A step of reducing the pressing force of the cylinder by a predetermined amount in order to weaken the repulsive force of the compressed waste plastic, and a step of opening the casing while compressing the waste plastic with the reduced pressing force and binding it with a binding material And retrieving the bound waste plastic by retracting the cylinder. [0008] According to the method for compressing and reducing waste plastic according to the present invention, a press having a high pressing force is used to increase the compression and volume reduction rate, and a waste plastic is used. Is configured to be capable of switching between a high pressing force used when compressing and reducing the volume and a low pressing force of about half of the pressing force. Then, the collected waste plastic is filled into the casing of the press machine by a predetermined amount, and the cylinder is advanced and retracted to repeatedly compress and reduce the volume a plurality of times. For example, switch the pressing force of the cylinder to a low pressure of about half, reduce the strong repulsive force (restoring force) of the waste plastic that has been compressed and reduced at high pressure, and then open the casing. Bundling with binding material. When the binding is completed, the cylinder is retracted to take out the bound waste plastic. As described above, when binding the waste plastic compressed and reduced in volume at a high pressure, if the pressing force of the cylinder is slightly reduced, the repulsive force of the waste plastic caused by the compression can be reduced somewhat, and even if the casing is opened. Inconveniences such as vigorously blowing air or suddenly expanding the door are reduced, and the binding material is less likely to be cut due to the repulsive force of the waste plastic. By adopting such a process, a high-pressure press can be used, and the volume reduction rate can be considerably increased as compared with the conventional case. Embodiments of the present invention will be described below with reference to the drawings. 1 is a vertical press used for compressing and reducing waste plastic such as used styrofoam and PET bottles. A casing 2 as a main body and a casing 2 for the casing 2 are provided. The hydraulic cylinder 3 disposed at the top constitutes a main body. A plurality of doors 4, 5, 6, 7 are provided on the front and one side of the casing 2 so as to be openable and closable. Open and close appropriately. The door 7 on the side of the casing 2 is provided so that even if the compressed waste plastic firmly adheres to the inner wall of the casing 2, it can be easily taken out. Further, the door 6 is provided with a return prevention mechanism 8 for preventing the waste plastic immediately after compression from being restored to the original bulk, and the blade 9 having the shape shown in FIG. The blades 9 are buried in the door 6 when the waste plastic is compressed, and are protruded into the casing 2 by a biasing mechanism such as a spring when the compression is released, and the compressed waste plastic is pressed from above. To maintain the bulk during compression. The hydraulic cylinder 3 comprises a cylinder body 10, a piston rod 11, and a piston rod 11.
The piston plate 11 is made up of a press plate 12 fixed to the distal end portion, and the piston rod 11 is expanded and contracted by hydraulic pressure supplied from a hydraulic unit (not shown) arranged in the vicinity.
, The waste plastic filled in the casing 2 is compressed and reduced in volume. Reference numeral 13 denotes a control panel for the hydraulic cylinder 3, which controls the basic operation of the press machine such as driving and stopping the hydraulic cylinder 3, and a high pressing force at the time of compressing and reducing the volume. And has a function of controlling switching between the low pressure and the low pressure. The normal pressing force of the press controlled by the control panel 3 is, for example, a high pressure of not less than 20 kg / cm @ 2, and the low pressing force is about half of 10 kg / cm2.
cm ↑ 2, but the specific numerical values of these pressing forces may be set as appropriate according to the target object. A plurality of slits 14 are formed on the back surface of the casing 2 so that a binding material such as a binding band can be inserted therethrough. The same number of grooves 15 and 16 are provided so as to coincide with the position of the slit 14 so that the waste plastic that has been reduced in volume can be bound and wound around the waste plastic while being pressed by the press plate 12. ing. Next, an operation process for compressing and reducing the volume of waste plastic such as styrofoam or PET bottles using the press machine will be described with reference to the flowchart of FIG. Note that S1 to S9 in the drawing represent work steps. First, the binding material is creeped along the groove 15 on the floor inside the casing 2, and one end thereof is arranged in front of the press machine 1 and the other end is arranged behind the press machine 1 via the slit 14. This is done (S1). Next, with only the door 4 opened, waste plastic is charged through the opening and filled into the casing 2 (S2). This loading operation may be performed manually by an operator, or may be performed with a conveyor or the like facing the opening of the door 4. Next, the casing 4 is closed by closing the door 4, and the hydraulic cylinder 3 is driven to compress the waste plastic in the casing 2 with a high pressing force to reduce the volume (S).
3). Then, after the lapse of the set time, the pressing force of the hydraulic cylinder 3 is switched to a low pressure to reduce the pressing force (S4). As a result, the strong repulsion of the waste plastic, which is generated by the compression and volume reduction at a high pressure, is slightly weakened. Then, it is confirmed whether the compressed and reduced waste plastic has become a lump of a size to be taken out (S5),
If the size is not the same, the hydraulic cylinder 3 is retracted (S6), the process returns to step S2, and waste plastic is additionally charged again, and compression and volume reduction are repeated as described above.
Here, as a method of checking whether or not the waste plastic has become a lump of a size to be taken out, the worker may check each time visually or may be provided with some kind of sensor. . On the other hand, when the waste plastic becomes a lump of a size to be taken out of the casing 2, the doors 6 and 7 are opened while the waste plastic is compressed at a low pressure, and the binding material is wrapped around the waste plastic. Slit 14, casing 2
Winding is performed using the internal groove 15 and the groove 16 on the bottom surface of the press plate 12 to perform binding (S7). At this time, when the doors 6 and 7 are opened, the repulsive force from the waste plastic is sufficiently weakened, so that the air blows out from the inside of the casing 2 vigorously, or the doors 6 and 7 are pushed open rapidly. Scattering of waste plastic is minimized. Then, after retracting the hydraulic cylinder 3,
The waste plastic that has been bound by the binding material is taken out of the casing 2 (S8). Then, it is confirmed whether or not to continue the compression processing (S9). If the compression processing is to be continued, the process returns to step S1 to perform the compression and volume reduction processing of the waste plastic in the same manner as described above, and otherwise terminates the processing. As described above, according to the present invention, when bundling the compressed waste plastic, the pressing force of the hydraulic cylinder 3 is reduced to reduce the repulsive force of the waste plastic to some extent before the casing 2 is opened. Therefore, it is possible to reduce the problem that the air is blown out vigorously or the door is suddenly pushed open. Also, the binding material is less likely to break due to the repulsive force of the waste plastic. By adopting such a process, it is possible to use a press machine having a higher pressing force, and it is possible to increase the volume reduction rate as compared with the related art. In the flowchart of FIG. 5, the timing for reducing the pressing force of the hydraulic cylinder 3 when compressing the waste plastic is performed every time the waste plastic is compressed. However, the pressing force may be reduced only immediately after the final compression and after the bundling. In this embodiment, the vertical press 1 has been described. However, the present invention is not limited to this, and a horizontal press may be used. As described above, according to the method for compressing and reducing the volume of waste plastic according to the present invention, the method for compressing and reducing the volume of waste plastic such as used polystyrene foam and PET bottles using a high-pressure press machine is used. There is a step of introducing and filling the waste plastic in the casing of the press machine, a step of compressing the waste plastic filled in the casing with a cylinder, and a step of reducing the repulsion force of the compressed waste plastic by using a cylinder. A step of reducing the pressing force by a predetermined amount, a step of opening the casing while compressing the waste plastic with the reduced pressing force, and binding with a binding material; and After the waste plastic is compressed and reduced in volume by a press, the pressing force of the cylinder is reduced when the casing is opened. Since the repulsive force of the volume-reduced material has been reduced somewhat, even when using a press machine with a high pressing force, air can be blown out vigorously when the casing is opened or the door can be suddenly pushed open. In addition to being able to reduce the amount, the binding material can be less likely to break due to the repulsion of the waste plastic. Further, if this compression volume reduction method is adopted, a high-pressure press machine can be used, and the volume reduction rate of waste plastic can be increased as compared with the conventional case.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a press used in a method for compressing and reducing waste plastic according to the present invention. FIG. 2 is a side view of FIG. FIG. 3 is a plan view of FIG. 1; FIG. 4 is a view showing a state in which a door on the front side of the press in FIG. 1 is opened. FIG. 5 is a flowchart showing an operation process for compressing and reducing the volume of waste plastic. [Description of Signs] 1 ... Pressing machine 2 ... Casing 3 ... Hydraulic cylinder 13 ... Control panel

Claims (1)

Claims 1. A method for compressing and reducing the volume of waste plastic such as used styrofoam and PET bottles using a high-pressure press, wherein the waste plastic is charged into a casing of the press. Performing the step of compressing the waste plastic filled in the casing with a cylinder, reducing the pressing force of the cylinder by a predetermined amount to weaken the repulsive force of the compressed waste plastic, and the reduced pressing force. A step of opening the casing in a state where the waste plastic is compressed and bundling it with a binding material; and a step of retracting the cylinder to take out the bound waste plastic. Method.