JPS6220263Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applied to the production of thermoplastic films such as polypropylene, polyethylene, and polyester. The present invention relates to a recycling processing device that performs the necessary processing on slit loss, defective raw materials, etc. in order to make them available for reuse.

<Prior Art> Film flaps and the like are too bulky in their original state and are inconvenient to handle for reuse.
For this reason, film edges and the like have conventionally been subjected to a process of being heat-pressed and then cut into small pieces for reuse. As a reprocessing technology for such thermoplastic films, the applicant has proposed
There is one disclosed in Publication No. 46-18271.

This involves heating a thermoplastic film that is continuously fed in one direction with a heater, passing it through a passage with a small diameter on the exit side, converging it, and then crimping it between the concave and convex fitting parts of a pair of compression rotating rolls. and then cut into small pieces.

<Problems to be solved by the invention> In the conventional heating, convergence, and crimping process for thermoplastic films, heating was first performed using a heater. In this case, if the heating temperature of the film is low, it will peel off again after being pressed, so it is desirable that the heating temperature be as high as possible. However, when the temperature exceeds a certain temperature (softening point), the physical properties of the film change, and it becomes impossible to mix it with so-called virgin pellets (used for the first time as a raw material for molding) and reuse it, reducing the product value. Therefore, the film needs to be uniformly heated to near its softening point temperature. However, since the film is constricted by the convergence passage, it takes on a conical shape before the entrance of the convergence passage. Then, the outer peripheral surface of the conical film can be heated, but
The inner circumferential surface cannot be sufficiently heated and the film temperature cannot be raised uniformly. Furthermore, since the film has a planar shape at a position away from the entrance of the convergence passage, it is possible to uniformly heat the entire surface, but heat loss increases because the film is away from the convergence passage. In addition, since the width of the film varies, in order to heat the film in a flat state, it is necessary to adapt the heater dimensions to the widest film, which is wasteful.

Next, when the film is crimped using the concave-convex fitting portion of the compression rotating roll, it is fine if the thickness or width of the film to be crimped is small, but if the thickness or width of the film is too large, a sufficient crimping force cannot be obtained.

In view of the above, an object of the present invention is to provide a thermoplastic film recycling device that can uniformly and efficiently heat the film regardless of its width in the film heating process, and can strongly compress the film in the compression process. do.

The technical means adopted by the present invention to solve the problems of the prior art and achieve the object are characterized by the provision of a heating mechanism 4, a converging mechanism 5, and a pressing mechanism 6 for a thermoplastic film 1 which is continuously fed in one direction, the heating mechanism 4 having blowout ports 9, 9 for blowing hot air of a predetermined temperature toward the film 1 from opposing positions approximately equidistant from the film 1 and a frame 11 for preventing the diffusion of the hot air, the converging mechanism 5 having a converging passage 12 whose diameter gradually decreases on the outlet side so that the film 1 heated by the hot air passes through and converges into a string-like shape,
The pressing mechanism 6 has a pair of compression rotating rolls 13a, 13b having mating grooves 17 and ridges 18 formed on their peripheral surfaces to press the film 1 converged after passing through the convergence passage 12 between the protrusions and recesses, and further has protrusions 22 arranged side by side on each of the opposing surfaces of the grooves 17 and the ridges 18.

<Function> Since hot air at a predetermined temperature is blown onto the film 1 from the air outlets 9, 9, which are located at opposing positions approximately equidistant from the film 1, the hot air collides with the film 1 at the film 1 position, causing high-temperature air to cover the film 1. An air region 36 will be formed. Furthermore, the diffusion prevention frame 11 prevents the hot air from spreading, thereby preventing the temperature inside the frame 11 from decreasing. As the film 1 passes through the convergence passage 12, it is gradually folded into a conical shape and converged into a string shape, and then the concave grooves 17 and the convex strips 1 of the compression rotation rolls 13a and 13b are formed.
8 and are crimped together. At this time, by the projections 22 arranged in parallel on the opposing surfaces of the groove 17 and the protrusion 18,
The area of pressure contact with the film 1 becomes smaller and the pressure force increases.

<Example> Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a recycling processing device 2 for a thermoplastic film 1 that is continuously fed in one direction (arrow B in the figure);
A cutting device 3 for the film 1 crimped into a string shape by the recycling device 2 is shown connected on a line. The regeneration processing apparatus 2 includes a heating mechanism 4, a convergence mechanism 5, and a pressure bonding mechanism 6.

In the heating mechanism 4, reference numerals 7, 7 are a pair of upper and lower hot air blowers, and the air sent from the blower 8 is heated by an internal heater (not shown) to each blower outlet 9,
A commercially available one is used that blows out from 9.
Here, the blow-off ports 9, 9 are arranged facing each other at positions approximately equidistant from the film 1, and blow hot air toward the film 1. The temperature of the hot air at this time is set to a predetermined temperature that can raise the temperature of the film 1 to the softening point temperature (the temperature immediately before the film changes its physical properties).
Since this temperature varies depending on conditions such as the material, shape, dimensions, and feeding speed of the film 1, it is set appropriately for each condition. In this embodiment, a temperature sensor 10 for measuring the hot air temperature is provided, and the commercially available hot air blower 7 is also capable of adjusting the hot air temperature. Note that the blow-off ports 9,9 are not limited to those arranged to blow from two opposite directions, but may be arranged to blow from four opposite directions, and the point is to blow hot air from the opposite directions toward the film 1 from approximately equal distances. Bye. Further, the heating temperature of the film 1 may be set to a temperature that allows the lubricant applied to the film 1 to be eluted, thereby eliminating slippage during the crimping process of the film 1 and obtaining good crimping.

Reference numeral 11 denotes a hot air diffusion preventing frame, which has a cylindrical shape with an inlet 11a and an outlet 11b for the film 1, and the blower ports 9, 9 are fitted in the upper and lower walls of the frame 11, so that the film 1 can be heated inside the frame 11. hot air is blown onto the surface.

Next, the convergence mechanism 5
It has a convergence passage 12 which is connected to 1b and through which the film 1 passes and converges into a string shape. The convergence passage 12 has a conical inner circumferential surface and a diameter that gradually becomes smaller toward the outlet side. Here, the convergence passage 12
Although the inner circumferential surface of the film 1 is not limited to a conical shape, convergence can be smoothly performed, and air existing between the films 1 can be smoothly removed during convergence. Further, the inner diameter of the convergence passage 12 is the same as that of the film 1.
It is preferable to have an appropriate size proportional to the thickness.

Next, the crimping mechanism 6 has a pair of compression rotating rolls 13a and 13b that crimp the film 1 converged into a string shape in the convergence passage 12 therebetween. Each roll 13a, 13b has a pair of left and right side rolls 14, 14, and a center roll 1 located between the side rolls 14, 14, as shown in FIG.
5 is removably connected to the center roll 15.
It can be replaced when it wears out. It is connected to a rotational drive source (not shown) via a drive shaft 16 and rotates in the direction in which the film 1 is fed. Here, in order to press the converged film 1 between the concave and convex portions, the lower compressing rotary roll 13b has a center roll 15 having a smaller diameter than the side rolls 14, 14, so that a concave groove 17 is formed on the circumferential surface of the lower compression rotary roll 13b. is formed. The upper compression rotary roll 13a has a center roll 15 having a diameter larger than that of the side rolls 14, 14, so that a protrusion 18 is formed on the circumferential surface of the roll 13a, which fits into the groove 17. Also, for crimping the film 1, a concave groove 17 and a convex strip 1 are provided.
Compressing rotation rolls 13a, 13b in the direction of fitting with 8.
The drive shaft 16 of the lower compression rotation roll 13b is supported so as not to be vertically movable, and the drive shaft 16 of the upper compression rotation roll 13a is supported so as to be vertically movable. A spring 19 is provided to bias the upper compression rotating roll 13a downward. It is also possible to fix the roll interval and compress without providing the spring 19, but if the spring 19 is used, the spring 19 can be pressed by the vertical moving body 21 screwed onto the fixed part 20 as shown in the figure. The elastic force can be adjusted, and even if the thickness of the film 1 varies, good crimping can be performed. Further, since the vertical drive shaft 16 has vertical play, there is less impact than when it is fixed, which is preferable in terms of strength.

Further, protrusions 22 are arranged in parallel on the opposing surfaces of the groove 17 and the protrusion 18. The method of forming this protrusion 22 is as shown in FIG.
An involute tooth profile 23 is formed on the circumferential surface of the tooth profile 23, and projections 22 are provided by forming irregularities on each tooth profile 23.
At this time, the protrusion 22 formation position is as shown in FIG.
protrusion 22b of the other center roll 15b between a
be located. (If this is not done, there is a risk that the film 1 will be cut if it is thin.) Next, reference numeral 24 is a guide roll, and 25a and 25b are a pair of feed rolls, each of which is rotationally driven. The film 1, which has been press-molded into a string shape, is fed into the cutting device 3, and at the same time, the slack of the film 1 is removed. This guide roll 24 is used to hold a plurality of films 1.
If some of the films are cut in the case of stacking and processing, the remaining films are heated more than necessary by the heating mechanism 4, increasing their adhesive strength, and causing sagging at the exits of the compression rotating rolls 13a and 13b. If there is any slack, there is a risk of it wrapping around the lower roll 13b, so the slack is removed to prevent this wrapping.

Further, the circumferential speeds of the feed rolls 25a and 25b are made slightly faster (increased by 10 to 20%) than the circumferential speeds of the compression rotary rolls 13a and 13b, and this also serves to eliminate slack in the film 1. Like the compression rotary rolls 13a and 13b, these feed rolls 25a and 25b also sandwich the film 1 by fitting the concave grooves and convex stripes on the circumferential surface of each roll, and have knurled eyes on the surface facing the concave and convex surfaces. The molding prevents the film 1 from slipping.
Also, similarly to the compression press rolls 13a and 13b, the drive shaft 26 of the lower feed roll 25b
b is supported so as not to be vertically movable, and the drive shaft 26a of the upper feed roll 25a is supported so as to be vertically movable. A spring 29 whose elastic force can be adjusted by a vertically movable body 28 screwed onto the fixed portion 27 presses the upper feed roll 25a in the direction of fitting the concave and convex portions. This eliminates taking-off errors due to variations in the thickness of the film 1. Further, a sensor 30 for detecting cutting of the film 1 is connected to the upper feed roll 25a. This means that when the film 1 is cut, the upper feed roll 2
5a moves to come into contact with the lower feed roll 25b, so it is like a well-known limit switch that detects its movement dimension, and in this embodiment, the operation of the entire apparatus is stopped by this detection. As a result, the film 1 is compressed by the lower compression rotating roll 13b.
Prevent it from getting wrapped around.

Next, 31 is a guide and feed roll 2
They are disposed on the left and right sides of the film 1 fed out from 5a and 25b, so that the film 1 is guided to the cutting device 3 without swinging from side to side. Reference numeral 32 designates an air blowing nozzle that blows air onto the film 1 from above in order to prevent the film 1 sent out from the feed rolls 25a and 25b from warping upward and wrapping around the feed roll 25a due to temperature changes. be. Note that the air sent to the air blowing nozzle 32 utilizes air from the blower 8 to save energy.

The cutting device 3 includes a fixed blade 33 and a rotationally driven rotary blade 34, and cuts the film 1, which is compressed into a string shape and is fed between the two blades 33 and 34, into small pieces called pellets 35. On this occasion,
If the crimped film 1 has a hard stiffness, a flat cutting blade may be used, and if the stiffness is soft, a cutting blade with a reed may be used to cut at a point.

In the above-mentioned recycling processing apparatus 2, hot air at a predetermined temperature is first blown toward the film 1 sent to the heating mechanism 4 from the air outlets 9, 9 located at two opposing positions approximately equidistant from the film 1. In addition, as shown in FIG. 3, the hot air collides with the film 1 at the position of the film 1 to form a high temperature air region 36 covering the film 1, so that the film 1 can be uniformly heated regardless of its width. Moreover, since the temperature drop inside the frame 11 can be suppressed by the hot air diffusion preventing frame 11, the thermal efficiency is good and it is economical.

The heated film 1 then passes through the convergence passage 12.
As shown in FIG. 4, it is gradually folded into a conical shape and converged into a string shape, and then the compression rotating rolls 13a, 13
The concave groove 17 and the protrusion 18 are crimped together. At this time, since the string-like film 1 is located between the irregularities, there is no risk of spreading in the width direction during crimping, and uniform and firm crimping can be achieved. And groove 17
Because of the protrusions 22 arranged in parallel on the opposite surfaces of the film 1 and the protruding strips 18, even if the film 1 has a large width or thickness, the pressure contact area becomes small, so that the film can be crimped with a large pressure, and the film 1 can be formed into a string shape. Film 1 will not peel off.

Next, in FIG. 5, the width of the film 1 is
This figure shows an embodiment of the regeneration processing apparatus 2 in which the inlet diameter is much larger than the inlet diameter of the inlet. When the width of the film 1 is smaller than the entrance diameter of the convergence passage 12, the film 1 is gradually converged from within or near the convergence passage 12 into a conical shape as shown in FIG. If the width of the film 1 is much larger than the diameter of the entrance of the convergence passage 12, it will take on the conical shape shown in FIG. 4 at a position quite far from the entrance. Therefore, in the embodiment shown in FIG. 5, an elliptical convergence guide 37 as shown in FIG. , air outlet 9,
The film 1 position where the hot air from 9 is blown is
The conical film 1 shown in FIG. 4 is at a position 38 where both ends thereof are closed together. Then, the hot air blown onto the film 1 from above and below collides with each other as shown in FIG. 7, forming a high temperature air region 36 covering the film 1 as in the case of FIG. 3, and having a conical shape. It also enters the inside of the film 1 and heats the film 1 uniformly. As a result, conventionally, in order to heat a wide film, it would be necessary to heat a wide film at a position further away from the converging passage entrance
Compared to heating the film when it is still in a flat state, it can be heated near the entrance of the converging passage 12, the temperature of the film will not drop before it is crimped and it will not peel off after crimping, and it has good thermal efficiency and is economical.

<Effects> According to the thermoplastic film recycling apparatus according to the present invention, hot air at a predetermined temperature is blown onto the film from the air outlet located at an approximately equal distance from the film that is continuously fed in one direction. In addition, the hot air collides with the film at the film position to form a high-temperature air region covering the film, allowing the film to be uniformly heated regardless of its width. Also,
Even if the film width is extremely large and takes on a conical shape in front of the entrance of the convergence passage, the hot air blown onto the film covers the conical outer circumference of the film and also penetrates into the film to uniformly heat the film. Since heating can be performed near the convergence passage, thermal efficiency is good, and peeling after pressure bonding can be prevented without lowering the temperature of the film. The diffusion prevention frame prevents hot air from dispersing and prevents a drop in temperature inside the frame, resulting in good thermal efficiency. In addition, since protrusions are arranged in parallel on the opposing surfaces of the concave grooves and protrusions of the compression rotary roll that presses the film converged into a string shape in the convergence passage, the area of pressure contact with the film is small and the pressing force is large. Even if the width or thickness of the film increases, it can be crimped securely.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of the configuration of a reprocessing device and a cutting device according to an embodiment of the present invention, Fig. 2 A is a cross-sectional view of the compression rotating roll, Fig. 2 B is an enlarged perspective view of the same main part, Fig. 2 C is a sectional view taken along the line A-A in Figure 2A, Figure 3 is an explanatory diagram of the state of hot air blown onto the film, and Figure 4 is a film that is folded into a conical shape and converged by the convergence mechanism. FIG. 5 is an explanatory diagram of the configuration of a reprocessing apparatus according to another embodiment, FIG. 6 is a front view of the convergence guide, and FIG. 7 is an explanatory diagram of the state of hot air blown onto the film. . DESCRIPTION OF SYMBOLS 1... Film, 4... Heating mechanism, 5... Convergence mechanism, 6... Pressing mechanism, 9... Air outlet, 11...
Diffusion prevention frame, 12... Convergence passage, 13a, 13
b... Compression rotating roll, 17... Concave groove, 18...
Convex ridge, 22...protrusion.

Claims (1)

[Scope of utility model registration request] Thermoplastic film 1 that is continuously fed in one direction
The heating mechanism 4 includes a heating mechanism 4, a convergence mechanism 5, and a pressure bonding mechanism 6, and the heating mechanism 4 has blow-off ports 9, 9 that blow out hot air at a predetermined temperature toward the film 1 from opposing positions approximately equidistant from the film 1. The hot air diffusion prevention frame 1
1, the convergence mechanism 5 has a convergence passage 12 whose diameter gradually decreases on the exit side so that the film 1 heated by hot air passes through and converges into a string shape, and the crimping mechanism 6 has a convergence passage 12 that gradually becomes smaller in diameter on the exit side so that the film 1 heated by hot air passes through and converges into a string shape. A pair of compression rotary rolls 13a and 13b are provided with grooves 17 and protrusions 18 that fit together on the circumferential surface in order to press the film 1 converged after passing through 12 between the concave and convex portions, and further A thermoplastic film recycling device characterized in that protrusions 22 are arranged in parallel on opposing surfaces of the grooves 17 and the protrusions 18.