Recycled pellet manufacturing method and device, and twisted cord manufacturing method and device

Abstract

To provide a method and an apparatus of manufacturing a recycled pellet capable of pelletizing loss films even with thickness and hardness that make the loss films difficult to be twisted even after preheating.SOLUTION: An apparatus of manufacturing a recycled pellet comprises: a loss film supply unit (12) that bundles one or more loss films (R) together and feeding out them as a bundled loss film (R1); a preheating unit (14) that heats the bundled loss film (R1) up to a softening temperature to form it to be a preheated bundled loss film (R2); a rolling unit (16) that rolls the preheated bundled loss film (R2) to make it to be a wide film-like rolled loss film (R3); and a rotary compression unit (18) that subjects the rolled loss film (R3) to twisting and point press-bonding to form it to be a press-bonded twisted cord (R5) with a recessed impression.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for producing recycled pellets using, for example, the edges of double film produced by inflation molding, which are scraps at both ends of the film, or other waste film generated during the manufacturing process (for example, double film with poor thickness or that has been torn during manufacturing), as raw materials, and to a method and apparatus for producing twisted string formed in a preliminary stage of the recycled pellets. [Background technology]

[0002] Known as a prior art of this type is the recycled pellet manufacturing apparatus described in Patent Document 1. This prior art recycled pellet manufacturing apparatus twists one or more loss films, and point-compresses the twisted portions to form twisted cords, and cuts these twisted cords to form recycled pellets, and has a technical feature in that, prior to stretching the loss film while twisting it, the loss film is preheated to its softening temperature, and further pre-stretched in the preheating step.

[0003] With conventional recycled pellet manufacturing equipment, the loss film is preheated to its softening temperature and stretched before being twisted, making it easier to twist thick or hard loss film that is difficult to twist. This makes it possible to pelletize not only thin and soft loss film, but also thick and hard loss film. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7004373 (Figure 1) Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional recycled pellet manufacturing equipment, although the preheating process has made it possible to significantly increase the types of waste film that can be pelletized, the thickness that can be twisted by preheating is limited to films of 150 μm or less at most. Therefore, there was a problem that films that are too thick or hard to be twisted even after preheating (for example, extremely thick waste films with a thickness of 300 μm or more, generally called sheets) could not be pelletized.

[0006] The present invention has been made to solve the problems of the prior art, and its object is to provide a method and apparatus for producing recycled pellets that can pelletize even loss film that is too thick or hard to twist even after preheating. Another object of the present invention is to provide a method and apparatus for producing twisted strings formed in a stage prior to the production of recycled pellets. [Means for solving the problem]

[0007] To achieve the above object, the present invention preheats one or more loss films R continuously supplied in one direction to their softening temperature, as shown in, for example, FIGS. The preheated loss film R2 is twisted, and the twisted portion is point-pressed to form a press-bonded twisted string R5 with concave indentations. The crimped twisted cord R5 with the concave indentations is cut to produce recycled pellets P. In the present invention, the crimped twisted cord R5 with concave indentations is made by using a preheated loss film R2. The preheated focusing loss film R2 is sandwiched between a pair of upper and lower pressure rollers 40a and 40b, and a pressing force is applied to one pressure roller 40b in a direction toward the other pressure roller 40a. The rolled loss film R3 is rolled to form a film-like rolled loss film R3, and the rolled loss film R3 is twisted and the twisted portion is point-pressed to form the film.

[0008] The recycled pellets P are produced by a recycled pellet manufacturing apparatus 10 as described below. The recycled pellet manufacturing apparatus 10 has a loss film supply section 12 that bundles one or more loss films R together and sends them out as a bundled loss film R1. The recycled pellet manufacturing apparatus 10 also includes a preheating unit 14 for heating the focusing loss film R1 to its softening temperature to form a preheated focusing loss film R2, and a heating unit 15 for heating the preheated focusing loss film R2. The preheated focusing loss film R2 is sandwiched between a pair of upper and lower pressure rollers 40a and 40b, and a pressing force is applied to one pressure roller 40b in the direction toward the other pressure roller 40a. Rolled into wide film-like rolled loss film R3 Has a pressure mechanism 44 and a rolling section 16. Furthermore, the recycled pellet manufacturing apparatus 10 of the present invention has a rotary compression section 18 that imparts twist to the rolled loss film R3 and point-presses it to impart concave indentations to form a crimped twisted string R5 with concave indentations. The rotary compressing section 18 also has a cutting section 20 for cutting the crimped twisted cord R5 with concave indentations, which is fed out from the rotary compressing section 18, to a predetermined length.

[0009] If the cutting section 20 is removed from the above invention, it is possible to make a twisted cord manufacturing method and twisted cord manufacturing device 200 as shown in FIG. [Effects of the Invention]

[0010] According to the present invention, the Ross film R2, which has been bundled and heated to its softening temperature, This is sandwiched between a pair of upper and lower rolling rollers 40a and 40b, and a pressing force is applied to one of the rolling rollers 40b in the direction toward the other rolling roller 40a. By rolling, a wide, thin rolled loss film R3 is formed. Then, this wide, thin rolled loss film R3 is twisted, and the twisted portions are point-pressed to form a press-twisted string R5 with concave indentations, which is then cut to form recycled pellets P. Therefore, regardless of the thickness or hardness of the raw material loss film, dense recycled pellets P with high bulk density can be formed, just like in the case of pelletizing a thin film-like loss film. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a front view showing a recycled pellet manufacturing apparatus according to the present invention. [Figure 2] FIG. 2 is a plan view of the recycled pellet manufacturing apparatus. [Figure 3] FIG. 10 is a diagram showing a loss film supply unit. [Figure 4] FIG. 2 is a diagram showing a loss film supply section, a preheating section, and a rolling section. [Figure 5] FIG. 10 is a diagram showing the operation of a preheating unit. [Figure 6] FIG. 2 is a diagram showing the main parts of a preheating section and a rolling section. [Figure 7] FIG. 2 is a plan view (partially in cross section) showing a rotary compression section and a cutting section. [Figure 8] FIG. 2 is a front view (partially in cross section) showing a rotary compression section and a cutting section. [Figure 9] FIG. 1 is a diagram showing a lace manufacturing device. DETAILED DESCRIPTION OF THE INVENTION

[0012] The present invention will be described below with reference to the drawings. Figures 1 and 2 are diagrams showing a recycled pellet manufacturing apparatus 10 according to the present invention. As shown in these figures, the recycled pellet manufacturing apparatus 10 of the present invention is roughly composed of a loss film supply section 12, a preheating section 14, a rolling section 16, a rotary compression section 18, and a cutting section 20.

[0013] In the above embodiment, the raw material loss film R changes shape at each step. Briefly, the wide raw material loss film R passes through the loss film supply section 12 and is narrowly bundled into a "bundled loss film R1." When this bundled loss film R1 reaches the preheating section 14, it receives heat from the preheating section 14 and becomes a "preheated bundled loss film R2." The preheated bundled loss film R2 is rolled in the rolling section 16 to become a "rolled loss film R3." The rolled loss film R3 is twisted between the rolling section 16 and the rotary compression section 18 to become a "twisted string R4." This twisted string R4 is then compressed by the compression rollers 82a and 82b of the rotary compression section 18 to become a "crimped twisted string R5 with concave indentations." The crimped twisted string R5 with concave indentations is then cut in the cutting section 20 to become a "recycled pellet P."

[0014] The raw material, loss film R, is a large amount of loss film (long, wide edges or product waste) that is generated during the manufacturing process of resin film (thermoplastic resin) using inflation molding or the T-die method. It comes in a variety of widths, thicknesses and types, and can be hard or thick and difficult to bend, or wide.

[0015] The loss film supply section 12 stacks or folds one or more sheets of wide loss film R, which are the raw material sent, vertically, and supplies them to the preheating section 14 as a single, thin, focused loss film R1. In this embodiment, the loss film supply section 12 is roughly composed of a first roller section 22 and a second roller section 24 (see Figure 3).

[0016] The first roller unit 22 has a pair of roller members 22a, 22a arranged at a predetermined interval, and the loss film R can pass through the gap between the roller members 22a, 22a.

[0017] A second roller unit 24 is disposed downstream of the first roller unit 22. The second roller unit 24 has a pair of roller members 24a, 24a disposed at a predetermined interval, allowing the loss film R to pass through the gap between the roller members 24a, 24a.

[0018] Here, the roller members 24a, 24a of the second roller unit 24 are arranged so that their rotation axes are perpendicular to the rotation axes of the roller members 22a, 22a of the first roller unit 22, and the wide loss film R that is the raw material passes through the loss film supply unit 12 (the first roller unit 22 and the second roller unit 24) and is supplied to the preheating unit 14 as a single, thin, focused loss film R1.

[0019] In this embodiment, the raw material loss film R is supplied to the loss film supply section 12 inline from a film forming machine (not shown), but the supply source may also be a reel (not shown) on which the loss film R is wound.

[0020] The number, width, thickness, hardness, etc. of the loss film R supplied to the loss film supply unit 12 are appropriately selected depending on the application of the recycled pellets P.

[0021] As another structure for the loss film supply section 12, for example, the structure described in Patent Document 1 (not shown) can be used (a narrowing section is provided at the outlet with a narrower width than the inlet, and the raw material loss film R is allowed to pass through this narrowing section).

[0022] The preheating section 14 is for heating the focusing loss film R1 to its softening temperature, and is composed of a heating section main body 26, an opening / closing lid 28, a lid opening / closing mechanism 30, and a hot air supply section 32 (FIGS. 4 to 6).

[0023] The heating unit main body 26 is a long member with a roughly U-shaped cross section, and has an opening 26a that opens along its entire length on one side (one of the moving side surfaces). An opening / closing lid 28 that opens and closes the opening 26a is attached to the heating unit main body 26 so as to be openable and closable via a hinge 26b, and when closed, it and the heating unit main body 26 form a rectangular cylindrical heating space Z.

[0024] The lid opening / closing mechanism 30 is opened and closed by the hinge mechanism as described above, and is opened and closed by the lid opening / closing cylinder 34.

[0025] The hot air supply unit 32 is composed of a hot air supply pipe 36 attached to the upper surface of the heating unit main body 26 and a heater 38 disposed inside the hot air supply pipe 36. Here, the hot air supply pipes 36 are provided in two locations, one on the inlet side and one on the outlet side of the heating unit main body 26. Each hot air supply pipe 36 is provided at an angle with respect to the heating unit main body 26 so that the hot air inlet side is located upstream of the heating unit main body 26 and the outlet side is located downstream of the heating unit main body 26.

[0026] Each hot air supply pipe 36 is connected to a blower (not shown) to send air into the heating unit main body 26. The temperature of the hot air sent into the heating unit main body 26 is controlled by a temperature sensor (not shown) installed in the heating unit main body 26, and the temperature is controlled so that the focus loss film R1 passing through the heating space Z reaches its softening temperature (e.g., 100°C to 500°C). When the focus loss film R1 reaches its softening temperature while passing through the heating unit main body 26, it becomes a preheated focus loss film R2 and exhibits rubber elasticity. The heating temperature is input in advance to a temperature control device (not shown) according to the type of loss film R used as raw material, and the optimal temperature is selected as appropriate.

[0027] The rolling section 16 is mainly composed of a pair of upper and lower rolling rollers 40 a and 40 b, a guide plate 42 , and a pressure mechanism 44 .

[0028] The rolling rollers 40a and 40b are used to roll the preheated focus loss film R2 into a thin film. In this embodiment, the upper rolling roller 40a is the driving side, and the lower rolling roller 40b is the pressure side.

[0029] The upper driving side rolling roller 40a can be rotated by a driving motor (not shown), and the lower pressure side rolling roller 40b is attached to a pressure mechanism 44 (described later) and can be moved toward or away from the driving side rolling roller 40a.

[0030] In this embodiment, the surfaces of the pair of upper and lower rolling rollers 40a and 40b are smooth, but they may be provided with irregularities (knurling or embossing) to prevent slippage of the preheated focus loss film R2 during rolling. The part where the preheated focus loss film R2 is sandwiched between the pair of upper and lower rolling rollers 40a and 40b becomes the "twist starting point K."

[0031] A guide plate 42 is attached to the side of each of the rolling rollers 40a and 40b on the moving side. The guide plate 42 is for reliably guiding the preheated focus loss film R2 into the gap between the pair of upper and lower rolling rollers 40a and 40b when the rolling unit 16 is moved from the retreat position to the rolling position (described later), and is formed by bending a plate-like member into a substantially L-shape.

[0032] The pressure mechanism 44 has both a "movement function" of moving the pressure side rolling roller 40b in a direction toward or away from the drive side rolling roller 40a, and a "rolling function" of applying a pressing force to the pressure side rolling roller 40b in a direction toward the drive side rolling roller 40a, and is roughly composed of a base 46, a first pressure plate 48, a second pressure plate 50, a pressure motor 52, and a compression spring 54.

[0033] The base 46 supports the pressure mechanism 44, and in this embodiment is formed by bending a plate material into a downward U-shape. Guide pins 46a are erected at the four corners of the top surface of the base 46, and a first pressure plate 48 is attached to these four guide pins 46a so that it can move axially. A circular hole 46b is formed in the center of the base 46, and a rotary shaft 52a of a pressure motor 52 attached to the back side of the base 46 is inserted into this circular hole 46b.

[0034] The first pressure plate 48 is a flat plate-like member, and guide pins 46a of the base 46 are inserted into insertion holes 48a provided at the four corners of the first pressure plate 48.

[0035] A screw hole 48b is formed in the center of the first pressure plate 48, and a feed nut 56 is attached to this screw hole 48b. A rotary shaft 52a of a pressure motor 52 is screwed into the screw hole 48b and the feed nut 56.

[0036] Four guide pins 48c are erected on the upper surface of the first pressure plate 48 so as to surround the feed nut 56. A compression spring 54 is attached to each guide pin 48c, and the tip of each spring is inserted into an insertion hole 50a provided in the four corners of the second pressure plate 50.

[0037] A shaft 50b is erected in the center of the upper surface of the second pressure plate 50, and a movable pressure roller 40b is rotatably attached to the tip of this shaft 50b.

[0038] In this embodiment, the preheating section 14 and the rolling section 16 are mounted on a common stand 58, which can be moved toward or away from the loss film R (more specifically, the focused loss film R1) by a stand drive section 60.

[0039] The platform drive unit 60 is installed below the platform 58 and is composed of a slide mechanism 62 (a slide block 62b equipped with a ball bearing on a guide shaft 62a) that enables the preheating unit 14 and the rolling unit 16 to move toward or away from the flowing loss film R (more specifically, the focused loss film R1), and a rotary motor 62c attached to the guide shaft 62a.

[0040] The rotary compression unit 18 is composed of a rotating unit 66, a compression unit 68 installed within this rotating unit 66, and a first drive unit 70 and a second drive unit 72 that rotate the rotating unit 66 and the compression unit 68 independently, and these are mounted on a stand 74 (Figures 7 and 8).

[0041] The rotating portion 66 is made up of a casing 76 and a first driven pulley 78, and the casing 76 is rotatably attached to a base 74 via front and rear bearings 80a and 80b.

[0042] The casing 76 of the rotating part 66 is divided into a front section 76a and a rear section 76b, and the front section 76a is cylindrical, and the first driven pulley 78 and one bearing 80a are mounted thereon.

[0043] The rear section 76b is a hollow rectangular box, with the front section 76a integrally projecting from its front end, and the other bearing 80b is attached to a cylindrical support section 76c projecting from the outlet section.

[0044] The compression section 68 is made up of upper and lower compression rollers 82a and 82b, upper and lower feed rollers 84a and 84b, a hollow main gear member 88 to which a second driven pulley 86 is attached, and a gear train 90 (FIG. 7) made up of a plurality of gears that mesh with the main gear member 88 and rotate the drive-side compression roller 82b and the drive-side feed roller 84b. Either of the compression rollers 82a and 82b or the feed rollers 84a and 84b may be the drive roller.

[0045] The main gear member 88 is composed of a main gear 88a and a hollow shaft portion 88b, and the hollow shaft portion 88b is rotatably housed in the front section 76a of the casing 76, and the second driven pulley 86 is attached to the part that protrudes outside the front section 76a.

[0046] A main gear 88a is provided at the end of the hollow shaft portion 88b inside the casing 76, and the main gear 88a is disposed so as to face the notched window 76d of the casing 76.

[0047] A driven gear 92 is provided on the outside of the casing 76 so that a portion of it enters the casing 76 through the notched window 76d, and meshes with the main gear 88a through the notched window 76d.

[0048] A worm gear 94 is attached to the rotation shaft of the driven gear 92, and is engaged with a worm wheel 96. The worm wheel 96 is attached to one end of the rotation shaft 82c of the drive-side compression roller 82b.

[0049] 7, a first transmission gear 98 is attached to the other end of the rotating shaft 82c of the drive-side compression roller 82b, and a third transmission gear 102 is attached to the other end of the rotating shaft 84c of the drive-side feed-out roller 84b. Both the first transmission gear 98 and the third transmission gear 102 are meshed with an intermediate second transmission gear 100, and the drive-side feed-out roller 84b is set to rotate slightly faster, about 10%, than the drive-side compression roller 82b via the gear train 90 extending from the first transmission gear 98 to the third transmission gear 102.

[0050] The first drive unit 70 is composed of a first drive motor 104 and a first drive pulley 106 attached to the rotary shaft of the first drive motor 104, and the first drive pulley 106 and the first driven pulley 78 are connected by a first timing belt 108.

[0051] Similarly, the second drive unit 72 is composed of a second drive motor 110 and a second drive pulley 112 attached to its rotating shaft, and the second drive pulley 112 and the second driven pulley 86 are connected by a second timing belt 114.

[0052] The compression rollers 82a and 82b of the compression unit 68 are cylindrical members (or made by stacking a number of circular plates with a number of jagged protrusions on their outer peripheries) with a number of hemispherical (wart-like) or elliptical or trapezoidal protrusions 116 formed over the entire surface of their outer surfaces (see circles in Figure 7). A rotation shaft 82c is provided at the center of the pressure-side compression roller 82a and the drive-side compression roller 82b, and both ends of the shaft 82c are rotatably supported by the casing 76.

[0053] A compression force adjustment mechanism (not shown) is provided to adjust the pressure of the upper compression roller 82a, which is the pressure-applying side, against the lower compression roller 82b, which is the driving side and is the pressure-receiving side, using a spring (not shown). If there is no need to adjust the pressure, this mechanism may not be provided.

[0054] The pair of upper and lower delivery rollers 84a and 84b of the compression unit 68 are disposed downstream of the compression rollers 82a and 82b, and, like the compression rollers 82a and 82b, their respective rotation shafts 84c are rotatably supported by the casing 76. The rotational force of the drive-side compression roller 82b is transmitted to the drive-side delivery roller 84b by a gear train 90 extending from the first transmission gear 98 to the third transmission gear 102.

[0055] Like the compression rollers 82a and 82b, the feed rollers 84a and 84b are also provided with a compression force adjustment mechanism (not shown) that uses a spring to adjust the pressure of the upper feed roller 84a, which is the pressure-applying roller, against the lower drive roller 84b, which is the pressure-receiving roller. If there is no need to adjust the pressure, this mechanism need not be provided.

[0056] The relationship between the drive-side compression roller 82b and the drive-side rolling roller 40b is set so that the drive-side compression roller 82b rotates faster than the drive-side rolling roller 40b, so that a stretching force (stretching force) is applied to the rolled loss film R3 transported between the rolling rollers 40a and 40b and the compression rollers 82a and 82b.

[0057] In the rotary compression unit 18, the casing 76 of the rotating unit 66 and the main gear member 88 of the compressing unit 68 can be rotated independently. First, in the rotating unit 66, the casing 76 is rotated by driving the first drive motor 104 of the first drive unit 70. As a result, twist is applied to the rolled loss film R3 between the rolling rollers 40a and 40b and the compression rollers 82a and 82b, and a twisted cord R4 is formed.

[0058] Meanwhile, in the compression unit 68, the main gear member 88 is rotated by driving the second drive motor 110 of the second drive unit 72. When the main gear member 88 rotates, its rotational force is transmitted to the driven gear 92, worm gear 94, and worm wheel 96, causing the drive-side compression roller 82b to rotate. The twisted string R4 is sandwiched from above and below by the pair of upper and lower compression rollers 82a and 82b, and is strongly compressed by the protrusions 116 on the surfaces of the compression rollers 82a and 82b. As a result, concave indentations are imparted to the surface of the twisted string R4, forming a crimped twisted string R5 with concave indentations. In this embodiment, the rotation unit 66 and compression unit 68 are operated simultaneously.

[0059] The crimped twisted string R5 with concave indentations formed inside the casing 76 of the rotary compression unit 18 is sent out from the protruding support portion 76c, which serves as the outlet portion. The crimped twisted string R5 with concave indentations sent out from the rotary compression unit 18 to the cutting unit 20.

[0060] The cutting section 20 is a section that cuts the crimped twisted cord R5 with concave indentations sent out from the rotary compression section 18, and is roughly composed of a cutter 118, a motor 120 with a speed changer, and a recycled pellet recovery box 122.

[0061] The cutter 118 cuts the crimped twisted cord R5 with concave indentations sent out from the rotary compression section 18, and its rotary shaft 118a is connected to a variable speed motor 120. The rotation speed of the cutter 118 can be changed as desired by adjusting the rotation speed of the variable speed motor 120, and is set appropriately taking into consideration the feed speed of the crimped twisted cord R5 with concave indentations and the size of the desired recycled pellets P.

[0062] A recycled pellet recovery box 122 is provided at the lower end of the cutter 118, and recycled pellets P formed by cutting the crimped twisted string R5 with concave indentations with the cutter 118 fall under their own weight and are stored in the recycled pellet recovery box 122.

[0063] Next, we will explain the method for manufacturing recycled pellets P using this recycled pellet manufacturing apparatus 10. First, one or more wide loss films R as raw material are set in the loss film supply unit 12 as specified. When there are multiple wide loss films R, they are pulled together and stacked one on top of the other, and their leading ends are lightly twisted to form a bundle.

[0064] The bundled loss film R is then inserted through the loss film supply section 12 (specifically, between the roller members 22a of the first roller section 22 and the roller members 24a of the second roller section 24), between the pair of compression rollers 82a and 82b of the rotary compression section 18, between the delivery rollers 84a and 84b, and through the support section 76c, in that order, with its leading end facing the cutter 118. The preheating section 14 and the rolling section 16 are in their retracted positions when the loss film R is set, and the loss film R is set to the side of the preheating section 14 and the rolling section 16.

[0065] When the setting of the loss film R is completed as described above, the power supply to the recycled pellet manufacturing apparatus 10 is turned on to perform a warm-up operation.

[0066] (Preparatory run) In the preparatory operation stage of the recycled pellet manufacturing apparatus 10, heating begins in the preheating section 14. In the preheating section 14, the heater 38 is energized, and the air passing through the hot air supply pipe 36 is heated to a predetermined temperature (the softening temperature of the raw material loss film R) and is then blown into the heating section main body 26. The hot air blown into the heating section main body 26 is discharged to the outside from openings at both ends (particularly the downstream opening) and heats the rolling rollers 40a and 40b located downstream thereof.

[0067] When the heating space Z of the heating unit main body 26 reaches a predetermined temperature, the rotary motor 62c of the frame drive unit 60 is operated to move the preheating unit 14 and the rolling unit 16, which are in the retracted positions, forward so that the loss film R passes through the preheating unit 14 and the rolling unit 16. This point will be explained below.

[0068] In the preheating section 14, first, the lid opening / closing cylinder 34 is operated to open the opening / closing lid 28 (FIG. 5(a)), and then the rotary motor 62c of the stand driving section 60 is operated to move the stand 58, which was in the retracted position, forward, and move the heating section main body 26 of the preheating section 14 to the heating position surrounding the loss film R (FIG. 5(b)). Next, the lid opening / closing cylinder 34 is operated to close the opening / closing lid 28, allowing the loss film R to pass through the heating space Z (FIG. 5(c)).

[0069] Meanwhile, in the rolling unit 16, the rotary motor 62c of the frame drive unit 60 is operated to move the frame 58, which was in the retracted position, forward, thereby moving the upper and lower rolling rollers 40a and 40b to the rolling position. When the upper and lower rolling rollers 40a and 40b have moved to the rolling position, the loss film R will get into the gap between the rolling rollers 40a and 40b. A guide plate is provided in front of the rolling unit 16, so that the loss film R can be reliably guided into the gap between the rolling rollers 40a and 40b.

[0070] Once it is confirmed that the loss film R has entered the gap between the rolling rollers 40a and 40b, the pressure motor 52 is then operated to move (raise) the first pressure plate 48 toward the driving side rolling roller 40a.

[0071] When the first pressure plate 48 rises, the second pressure plate 50 rises together with the compression spring 54, pushing up the pressure-side rolling roller 40b. Eventually, when the pressure-side rolling roller 40b comes into contact with the drive-side rolling roller 40a, the pressure-side rolling roller 40b also begins to rotate in unison with the rotation of the drive-side rolling roller 40a.

[0072] When the pressure motor 52 is operated in this state, the compression spring 54 is bent between the first pressure plate 48 and the second pressure plate 50, and the resilient force is transmitted to the pressure-side rolling roller 40b via the shaft 50b. As a result, a very large compressive force (200 kgf in this embodiment) is applied between the drive-side rolling roller 40a and the pressure-side rolling roller 40b, thereby rolling the loss film.

[0073] When the preparatory operation of the recycled pellet manufacturing apparatus 10 is completed as described above, the production of recycled pellets P finally begins. In this embodiment, the loss film R is caused to flow during the preparatory operation, but the loss film R may be caused to flow after the preparatory operation is completed. In this embodiment, the loss film R is caused to flow by operating the compression rollers 82a and 82b and the delivery rollers 84a and 84b of the rotary compression section 18, which will be described later. However, the loss film R may also be caused to flow by disposing a take-up roller (not shown) downstream of the rotary compression section 18 and taking up the loss film R with this take-up roller.

[0074] (Focusing process) First, in the loss film supply section 12, the raw material loss film R passes between the roller members 22a of the first roller section 22 and between the roller members 24a of the second roller section 24, whereby it is squeezed or folded into a single, thin bundled loss film R1 (bundling process). The single, thin bundled loss film R1 is then sent to the preheating section 14.

[0075] (Preheating process) The focusing loss film R1 sent to the preheating section 14 receives hot air from the hot air supply pipe 36 while passing through the heating section main body 26, and is heated to the softening temperature of the loss film R. The focusing loss film R1 heated to the softening temperature of the loss film R becomes a preheated focusing loss film R2 and begins to exhibit rubber elasticity.

[0076] The hot air sent from the hot air supply pipe 36 into the heating unit main body 26 flows in a rotating manner within the heating space Z, heating not only the surface of the focusing loss film R1 but also its interior to some extent, and then is discharged mainly from the opening at the rear of the heating unit main body 26 to the rolling unit 16.

[0077] The preheated focusing loss film R2 passing through the heating unit main body 26 is only subjected to tension during winding, so although it is heated to its softening temperature, it hardly stretches, and the preheated focusing loss film R2 does not stretch significantly.

[0078] In addition, if slack occurs in the preheated bundle loss film R2 passing through the heating unit main body 26 in the preheating step, a motor-driven nip roll (not shown) may be disposed between the second roller unit 24 of the loss film supply unit 12 and the heating unit main body 26 of the preheating unit 14. By setting the feed speed of the nip roll to be slower than that of the rolling rollers 40a of the rolling unit 16 described below, it becomes possible to apply tension and stretch to the preheated bundle loss film R2.

[0079] (Rolling process) The preheated focusing loss film R2 sent to the rolling section 16 passes between the driving-side rolling roller 40a and the pressure-side rolling roller 40b and is rolled by the extremely large compressive force applied between the rolling rollers 40a and 40b. Here, the preheated focusing loss film R2 reaches its softening temperature and has rubber elasticity, so the preheated focusing loss film R2 is crushed by the rolling and becomes a wide rolled loss film R3 with a thickness of approximately 20 to 30 μm. Because the rolling rollers 40a and 40b are sufficiently heated by the hot air from the preheating section 14, the preheated focusing loss film R2 in contact with the rolling rollers 40a and 40b does not cool below its softening temperature, allowing the preheated focusing loss film R2 to be effectively rolled.

[0080] The wide, thin rolled loss film R3 formed by passing through the rolling section 16 is sent to the rotary compression section 18, where it is twisted between the rolling rollers 40a and 40b of the rolling section 16 and the compression rollers 82a and 82b of the rotary compression section 18 to form a twisted string R4, which is then compressed by the compression rollers 82a and 82b to form a compressed twisted string R5 with concave indentations. The operation of the rotary compression section 18 will now be described.

[0081] First, the movement of the rotating unit 66 will be described. When the rotating unit 66 starts to drive, the casing 76 begins to rotate. This starts the "twisted cord forming process" in which the rolled loss film R3 is twisted to form a twisted cord R4. Note that the rolled loss film R3 passes through the center of the casing 76, so the casing 76 rotates around the rolled loss film R3 as its center of rotation.

[0082] (Twisted string forming process) In the twisted cord forming process, the first drive motor 104 of the first drive unit 70 is driven. When the first drive motor 104 rotates, its rotational force is transmitted to the front section 76a of the casing 76 via the first timing belt 108 and the first driven pulley 78, and the casing 76 begins to rotate around the rolled loss film R3. When the casing 76 rotates, the compression rollers 82a and 82b mounted inside the casing 76 also rotate together with the casing 76.

[0083] The rolled loss film R3 is sandwiched from above and below between the rolling rollers 40a and 40b and the compression rollers 82a and 82b of the rolling section 16, and in this state the compression rollers 82a and 82b rotate together with the rotation of the casing 76. As a result, the wide, thin film-like rolled loss film R3 between the rolling rollers 40a and 40b and the compression rollers 82a and 82b is twisted with the twist starting point K at the point where it is sandwiched between the rolling rollers 40a and 40b, to become a twisted cord R4.

[0084] In this embodiment, the casing 76 is set to rotate 5 to 10 times per second during the twisted cord formation process, which applies sufficient twist to the wide, thin rolled loss film R3 between the rolling rollers 40a and 40b and the compression rollers 82a and 82b, turning it into a tight, thin twisted cord R4.

[0085] Meanwhile, in the compression section 68, the compression rollers 82a and 82b rotate, drawing the twisted string R4 into the rotary compression section 18 and point-crimping it to form a crimped twisted string R5 with concave indentations (point-crimping process), and then sending this crimped twisted string R5 with concave indentations toward the cutting section 20 (feeding process).

[0086] (Point crimping process) In the point crimping process, the operation of the second drive unit 72 is started. When the second drive motor 110 of the second drive unit 72 starts to rotate, the rotational force is transmitted to the main gear member 88 via the second timing belt 114 and the second driven pulley 86, and the main gear member 88 starts to rotate. Then, the main gear 88a of the main gear member 88 rotates the side driven gear 92, which rotates the drive-side compression roller 82b in the feed direction of the twisted cord R4 via the worm gear 94 and the worm wheel 96.

[0087] The pressure-side compression roller 82a is pressed firmly against the drive-side compression roller 82b, and this pressing force (frictional force due to contact) causes both the drive-side compression roller 82b and the pressure-side compression roller 82a to rotate in the feed direction of the twisted string R4, drawing the twisted string R4 into the rotary compression section 18 at high speed.

[0088] The twisted cord R4 is tightly clamped between the pair of upper and lower compression rollers 82a and 82b with a predetermined pressing force, and as the twisted cord R4 is pulled into the rotary compression section 18, the protrusions 116 formed on the outer circumferential surface of the twisted cord R4 continuously form deep concave indentations on both the upper and lower surfaces, thereby point-bonding the twisted cord R4 to form a crimped twisted cord R5 with concave indentations. In the crimped twisted cord R5 with concave indentations, the films are firmly bonded together by the concave indentations.

[0089] The compression rollers 82a and 82b have protrusions 116 formed on their outer surfaces that penetrate deeply into the crimped twisted cord R5 with concave indentations, causing the crimped twisted cord R5 to get caught in the compression rollers 82a and 82b and making it difficult to feed out. Therefore, the feed-out rollers 84a and 84b feed out the crimped twisted cord R5 with concave indentations toward the cutting section 20 (feed-out process).

[0090] In this embodiment, the "twisted cord forming process" and the "point pressure bonding process" are performed simultaneously when the recycled pellet manufacturing apparatus 10 starts operating, but the "point pressure bonding process" may also be performed after the "twisted cord forming process".

[0091] (Sending process) A first transmission gear 98 is attached to the other end of the drive-side compression roller 82b, and a third transmission gear 102 attached to the drive-side feed-out roller 84b rotates via a second transmission gear 100. The pressure-side feed-out roller 84a presses the crimped twisted cord R5 with concave indentations against the drive-side feed-out roller 84b with a constant pressure while clamping the crimped twisted cord R5 with concave indentations, so the pressure-side feed-out roller 84a also rotates in the feed direction and feeds the crimped twisted cord R5 with concave indentations toward the cutting section 20.

[0092] The feed rollers 84a and 84b rotate in the feed direction slightly faster than the compression rollers 82a and 82b, and therefore apply tension to and pull up the crimped twisted cord R5 with concave indentations that is sandwiched between the compression rollers 82a and 82b and difficult to pull out because the protrusions 116 are deeply embedded in the concave indentations. As a result, the crimped twisted cord R5 with concave indentations is smoothly pulled out from between the compression rollers 82a and 82b and sent out from the support portion 76c of the casing 76 toward the cutting portion 20, where the crimped twisted cord R5 with concave indentations is cut (cutting process).

[0093] (cutting process) The crimped twisted cord R5 with concave indentations sent out from the rotary compression section 18 is continuously cut by the rotation of the cutter 118 to successively form recycled pellets P. The recycled pellets P cut by the cutter 118 fall under their own weight and are successively stored in a recycled pellet recovery box 122.

[0094] The concavely indented crimped twisted string R5 is cut at intervals that include at least one concave indentation, preferably at intervals that are wider than the intervals between the concave indentations formed on its surface, to produce recycled pellets P.

[0095] According to the recycled pellet manufacturing apparatus 10 of this embodiment, the raw material loss film R is bundled into a thin strip, heated to its softening temperature, and then rolled to form a wide, thin rolled loss film R3. This wide, thin rolled loss film R3 is then "twisted" and "crimped" to form a crimped twisted string R5, which is then cut to form recycled pellets P. Therefore, regardless of the thickness or hardness of the raw material loss film, a dense recycled pellet P with high bulk density can be formed.

[0096] It is also possible to remove the cutting section 20 from the above-mentioned recycled pellet manufacturing apparatus 10 and use the resulting twisted cord manufacturing apparatus 200, which is made up of the loss film supply section 12, preheating section 14, rolling section 16, and rotary compression section 18 (see Figure 9).

[0097] The crimped twisted cord R5 with concave indentations formed by the twisted cord manufacturing apparatus 200 has a high density and is difficult to stretch even when pulled, so it can be used as a packing cord or a cord for handicrafts. Of course, the twisted cord manufacturing apparatus 200 can also be used as a means for reducing the volume of cutting waste (this is also true for the recycled pellet manufacturing apparatus 10). [Explanation of symbols]

[0098] 10: Recycled pellet manufacturing device, 12: Loss film supply section, 14: Preheating section, 16: Rolling section, 18: Rotation compression section, 20: Cutting section, 22: First roller section, 22a: Roller member, 24: Second roller section, 24a: Roller member, 26: Heating section body, 26a: Opening, 26b: Hinge, 28: Opening and closing lid, 30: Lid opening and closing mechanism, 32: Hot air supply section, 34: Lid opening and closing cylinder, 36: Hot air supply pipe, 38: Heater, 40a: (Drive side) Rolling roller, 40b: (Pressure side) Rolling roller, 42: Guide plate, 44: Pressurization mechanism, 46: Base, 4 6a: guide pin, 46b: round hole, 48: first pressure plate, 48a: insertion hole, 48b: screw hole, 48c: guide pin, 50: second pressure plate, 50a: insertion hole, 50b: shaft, 52: pressure motor, 52a: rotating shaft, 54: compression spring, 56: feed nut, 58: base, 60: base drive unit, 62: slide mechanism, 62a: guide shaft, 62b: slide block, 62c: rotation motor, 66: rotating unit, 68: compression unit, 70: first drive unit, 72: second drive unit, 74: base, 76: casing, 76a: front stage, 76b : rear stage portion, 76c: support portion, 76d: notch window, 78: first driven pulley, 80a and 80b: bearings, 82a: pressure side compression roller, 82b: drive side compression roller, 82c: rotating shaft, 84a: movable side feed roller, 84b: drive side feed roller, 84c: rotating shaft, 86: second driven pulley, 88: main gear member, 88a: main gear, 88b: hollow shaft portion, 90: gear train, 92: driven gear, 94: worm gear, 96: worm wheel, 98: first transmission gear, 100: second transmission gear, 102: third transmission gear, 104: first drive motor , 106: first drive pulley, 108: first timing belt, 110: second drive motor, 112: second drive pulley, 114: second timing belt, 116: protrusion, 118: cutter, 118a: rotating shaft, 120: motor with transmission, 122: recycled pellet collection box, 200: twisted cord manufacturing device, K: starting point of twisting, P: recycled pellet, R: (raw material) loss film, R1: bundled loss film, R2: preheated bundled loss film, R3: rolled loss film, R4: twisted cord, R5: crimped twisted cord with concave indentation, Z: heating space

Claims

1. A method for producing recycled pellets, comprising preheating one or more loss films (R) continuously supplied in one direction to their softening temperatures, twisting the preheated loss films (R2), and point-pressing the twisted portions to form crimped twisted strings (R5) with concave indentations, and cutting the crimped twisted strings (R5) with concave indentations to produce recycled pellets (P), The preheated loss film (R2) is sandwiched between a pair of upper and lower rolling rollers (40a, 40b), and a pressing force is applied to one of the rolling rollers (40b) in a direction toward the other rolling roller (40a) to roll the preheated converged loss film (R2) into a film-like rolled loss film (R3), and the rolled loss film (R3) is twisted and the twisted portion is point-pressed to form a press-bonded twisted string (R5) with a concave indentation. This is a method for producing recycled pellets.

2. a loss film supply unit (12) that collectively supplies one or more loss films (R) as a focused loss film (R1); a preheating section (14) for heating the focus loss film (R1) to its softening temperature to form a preheated focus loss film (R2); a rolling section (16) including a pair of upper and lower rolling rollers (40a, 40b) that sandwich the preheated focus loss film (R2), and a pressure mechanism (44) that applies a pressing force to one of the rolling rollers (40b) in a direction toward the other rolling roller (40a) to roll the preheated focus loss film (R2) into a wide, film-like rolled loss film (R3); a rotary compression section (18) that imparts twist to the rolled loss film (R3) and point-presses it to impart concave indentations to form a crimped twisted string (R5) with concave indentations; and a cutting section (20) for cutting the crimped twisted string (R5) with concave indentations delivered from the rotary compression section (18) to a predetermined length.

3. A method for manufacturing a twisted cord, comprising preheating one or more loss films (R) continuously supplied in one direction to their softening temperatures, twisting the preheated loss films (R2), and point-pressing the twisted portions to form a crimped twisted cord (R5) with concave indentations, The preheated loss film (R2) is sandwiched between a pair of upper and lower rolling rollers (40a, 40b), and a pressing force is applied to one of the rolling rollers (40b) in a direction toward the other rolling roller (40a) to roll the preheated converged loss film (R2) into a film-like rolled loss film (R3), and the rolled loss film (R3) is twisted and the twisted portion is point-pressed to form a crimped twisted cord (R5) with concave indentations.

4. a loss film supply unit (12) that collectively supplies one or more loss films (R) as a focused loss film (R1); a preheating section (14) for heating the focus loss film (R1) to its softening temperature to form a preheated focus loss film (R2); a rolling section (16) including a pair of upper and lower rolling rollers (40a, 40b) that sandwich the preheated focus loss film (R2), and a pressure mechanism (44) that applies a pressing force to one of the rolling rollers (40b) in a direction toward the other rolling roller (40a) to roll the preheated focus loss film (R2) into a wide, film-like rolled loss film (R3); A twisted cord manufacturing device characterized by comprising a rotary compression section (18) that imparts twist to a rolled loss film (R3) and point-presses it to impart concave indentations, thereby forming a crimped twisted cord (R5) with concave indentations.

Images