JPH068316A - Vacuum forming method and vacuum forming device - Google Patents

Abstract

PURPOSE:To provide a vacuum forming method, which does not need so much energy cost, and the material cost of which does not put pressure upon the manufacturing cost of a formed article. CONSTITUTION:The vacuum forming device concerned consists of a feeder 6, an extruder 1 equipped with a flat die 5, a cooling roll 10, which cools extruded film material 9 down to the predetermined temperature, a vacuum former 12 having a plurality of molds 15 and 15 and a plug 19, a trimming cutter device 22 and a roller device 26, which sends scrap material 9' back to the feeder 6. By using the vacuum forming device, film material 9, which is produced with an extruder 1, is cooled with the cooling roll 10 down to the predetermined temperature so as to be fed to the vacuum former 12 in order to be formed into a formed article 11. The formed article 11 is separated with a trimming cutter device 22 from the film material 9 so as to send the film scrap material 9' back to the feeder 6 of the extruder 1 for recycling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a vacuum forming method for forming a container made of, for example, a synthetic resin from a film or sheet produced by an extruder using a vacuum forming machine, and a method for carrying out this method. The present invention relates to a vacuum forming device.

[0002]

2. Description of the Related Art A vacuum forming apparatus is well known in the art without mentioning the name of a document, and is generally constructed as shown in FIG. That is, a roll stand 31 that rotatably supports a separately manufactured film roll 30.
And the film 32 fed from the roll stand 31
A pair of heaters 33 for heating the mold to a predetermined temperature, and a mold device 35 in which a plurality of molds 34, 34 are provided downward.
And a plug device 36 provided corresponding to the plurality of molds 34, 34, and a die 3 for taking out a container 40 formed by the mold device 35 and the plug device 36 from the film 32.
8 and the general structure. Therefore, the film 32 fed from the roll stand 31 is heated to a predetermined temperature by the heater 33, supplied to the mold device 35, pressed by the plug device 36 to the molds 34, 34, and sucked by the vacuum device 39. Then, the film 32 is a mold 3
Containers 40, 4 which are closely attached to 4, 34, and have good transferability
0 and are molded. After that, the film 32 with the containers 40, 40 is attached to the die 38, and the containers 40, 40, and 40 are separated from the film 32 by the die 38. The film from which the container 40 is separated becomes the end material 32 '.

[0003]

As described above, the container 4 having good transferability even by the conventional vacuum forming apparatus described above.
It is possible to continuously mold 0, 40 ,. Also,
Since the cost of the molding process is reduced and the quality is improved, the conventional vacuum forming apparatus can be satisfied to some extent. To reduce the cost of the molding process, for example, a multi-station type, which is provided with a preheating device to shorten the molding time by a mold, is also adopted. In addition, as a quality improvement measure, negative pressure and air pressure are appropriately applied during molding,
The transferability is improved, and the thickness of the film is adjusted by locally controlling the heating of the film. Thus, various efforts have been made, but there are problems in the conventional vacuum forming apparatus or vacuum forming method. For example, as shown in FIG. 2, the film 32 unwound from the film roll 30 purchased as an original fabric is
Before it is supplied to the mold device 35, the heaters 33, 33 have to be separately heated to a temperature required for molding, and there is a drawback that energy cost for the heating is high. In general, when the resin container 40 is manufactured from the film 32 by this type of vacuum forming apparatus, 60
% Is used to mold the container 40,
End material 3 of the film 32 in which the containers 40, 40, are separated
2'is about 40%, and about half is discarded. When it is not disposed of, it is cheaply handed over to dealers as recycled waste. In this way, since the utilization of the film 32 is poor,
Currently, the material cost is high and the cost of the product is increasing. Therefore, it is an object of the present invention to provide a vacuum forming method that does not require energy cost and material cost does not press the cost of a molded product, and a vacuum forming apparatus used for carrying out this method. .

[0004]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention comprises a manufacturing step of supplying a synthetic resin to an extruder and manufacturing a film material by the extruder, and a manufacturing step manufactured by the manufacturing step. A cooling step of lowering the film material to a predetermined temperature, a film separating step of supplying the film material cooled to the predetermined temperature in the cooling step to a vacuum forming machine, and separating the molded article from the film material; It comprises a returning step of returning the film end material from which the molded product has been separated in the separating step to the supply port of the extruder, and is configured to continuously perform the above respective steps. The invention according to claim 2 is a resin supply means for supplying a synthetic resin to an extruder, an extruder for kneading and melting the synthetic resin supplied from the resin supply means and extruding it as a film material from a flat die, and an extruder. A cooling means for cooling the film material to a predetermined temperature, a vacuum forming machine having a plurality of molds and a plug, a die for separating a molded product formed by the vacuum forming machine, and a film in which the molded product is separated. The present invention according to claim 3, further comprising a conveying means for continuously returning the scrap material to the resin supplying means.
A vacuum forming machine is provided corresponding to the rotating body driven to rotate at a predetermined speed, a plurality of molds arranged on the outer peripheral portion of the rotating body at substantially equal intervals, and the mold of the rotating body. It is composed of at least one plug assist device and vacuum means which acts from the outside of the mold to make the inside a negative pressure.

[0005]

The invention according to claim 2 operates as follows. That is, the resin is supplied from the resin supply means to the extruder. Then, the resin is kneaded and melted in the extruder by a conventionally known action. Then, it is continuously extruded as a film material from the flat die. Since the extruded film material has a relatively high temperature, it is cooled by the cooling means to a temperature suitable for the molding temperature in the next step. In the vacuum forming machine, the plug presses the film material against the mold. At about the same time, negative pressure acts. Then, the film material comes into close contact with the mold, and a molded product having good transferability is formed. When the molding is completed, the plug is pulled up from the mold, and the molded product is removed from the mold while being attached to the film material. The film material with the molded product is sent to the die and the molded product is separated from the film. The film end material from which the molded product has been separated is immediately continuously conveyed by the roller device to the resin supply means, mixed with the resin raw material, and regenerated into the film material. In the same manner, molded articles are continuously molded.

[0006]

EXAMPLES In carrying out the present invention, it is desirable that the remaining end material after the molded product is separated is returned to the resin supply means in the state of a film. This is because the returning device can be composed of a drive roller, a guide roller, etc., and the structure is simple. Therefore, the figure shows an example in which the driving roller and the guide roller are used. However, it is also possible to immediately cut or crush the end material from which the molded product has been separated by a cutter or the like, and then return it to the resin supply means by a conveyor. At this time, if an air conveyor is used, pipe transportation can be performed, and therefore transportation becomes easy. When the film or sheet is returned to the resin supplying means, the returned film may be cut or crushed into a predetermined size with a cutter or the like and mixed into the raw material. . However, a cutting device such as a cutter is not shown in the drawing. Further, in the illustrated embodiment, the plug assist device is provided, but in the case of a product having a shallow bottom, the molding can be performed without the plug.

An embodiment of the present invention will be described below. As shown in FIG. 1, the vacuum forming apparatus according to the present embodiment is
Extruder 1, feeder 6 for supplying resin raw material J to extruder 1, cooling roll 10 for cooling sheet or film 9 extruded by extruder 1 to a predetermined temperature, and film 9 cooled to a predetermined temperature. Vacuum forming machine 12 for forming products 11, 11, and from film 9 to products 11, 1
Trimming cutter device 22 for separating 1 and
The roller device 26 for feeding the end material 9 ′, which is a separated film, to the feeder 6 side is constituted.

The extruder 1 has a well-known structure. That is, the main body mounted on the command bed 2 is equipped with an electric motor, a speed reducer, etc., and a screw 4 which is rotationally driven is provided in the cylinder 3. A flat die, for example, a T die 5 is attached to the die attachment head at the tip of the cylinder 3. The feeder 6 is also well known in the related art and is composed of a hopper 7 and the like. Feeder 6
Is a device for storing the resin raw material and smoothly supplying it to the supply port 8, and is provided with a preheating device, a drying device, a stirring device, and the like as necessary.

The cooling roll 10 is for cooling the high-temperature film 9 extruded from the T die 5 to a temperature required for the next molding, and is driven to rotate in accordance with the speed of the extruded film 9. A temperature-controlled cooling water, for example, is sprayed on the inner peripheral surface of the inner wall.

The molding device 12 comprises a rotary mold holder 13 having an octagonal shape in this embodiment, and a plug assist device 18.
It consists of and. The rotary die holder 13 is internally divided into eight hermetic chambers 14, 14. Although not shown in the drawing, compressed air and negative pressure may be applied to these airtight chambers 14, 14 via a rotary joint, or they may be opened to the atmospheric pressure. It has become. The airtight chambers 14, 14, ...
The molds 15 are arranged so as to face outward. Mold 15
Is for molding the outer shape of the product 11, and has a plurality of through holes 16, 16, at the bottom thereof. Therefore,
The airtight chambers 14, 14, and the inside of the mold 15 are pneumatically communicated with each other. The through holes 16, 16 may be provided in the side wall. The rotary mold holder 13
Although it is rotationally driven intermittently, the plug assist device 18 is provided at a position corresponding to the position where the mold 15 is stationary. The plug assist device 18 includes a plug 19 having a shape that makes a pair with the mold 15. The plug 19 is interlocked with the rotation of the rotary mold holder 13 and is pressed by the plunger 20 against the mold 15, as shown in the drawing. The mold 15 is driven so as to take a position away from the mold 15. This plug 19 preforms the product 11. Vacuum forming machine 1
2 is an air nozzle device 2 for cooling the molded product 11.
It also has 1.

The trimming cutter device 22 also has a conventionally well-known structure. The cutter base 25 on which the film 9 with the products 11, 11 is placed, and the plunger 23 are interlocked with the rotation of the rotary die holder 13. The cutter 24 is driven in the vertical direction.

The remaining films or scraps 9'where the products 11, 11, have been separated by the trimming cutter device 22.
Is returned to the supply port 8 by the roller device 26. The roller device 26 includes a feed roller 27, a guide roller 28, and a pair of drive rollers 29 that are driven in synchronization with the vacuum forming machine 12.
Etc.

Next, using the above vacuum forming apparatus, the product 11,
An example of molding Nos. 11, will be described. From the feeder 6, the resin J measured by, for example, a screw feeder is supplied to the supply port 8. Then, the resin J is sent forward by the rotation transfer action of the screw 4. When it is sent, it is kneaded and melted by the heat from the outside and the heat generation effect by the shearing force, the frictional force, etc. by the rotation of the screw 4. And T
The sheet or film 9 is continuously extruded from the die 5. Since the extruded film 9 has a relatively high temperature, it is cooled to a temperature suitable for the molding temperature in the next step by the cooling roll 10 that is rotationally driven. The film 9 is continuously extruded from the T-die 5, but is intermittently used in the molding device 12, and therefore is sent to the next molding device 12 with some slack.

In the vacuum forming machine 12, the film 9 is
It rides on a part of the rotary die holder 13 and is located between the die 15 and the plug 19 of the plug assist device 18. Rotary mold holder 1 corresponding to the plug assist device 18
Compressed air is supplied to the airtight chamber 14 of No. 3. Then,
Compressed air passes through the through holes 16, 16, of the mold 15 and the mold 15
To the inside of the, and inflate the film 9. As a result, the film 9 having an area necessary for molding the product 11 is secured. Next, the plunger 20 acts to move the plug 19 to the mold 1.
Pressed on 5. At approximately the same time, the airtight chamber 14 is set to a negative pressure. Then, the film 9 comes into close contact with the mold 15, and the product 11 having good transferability is formed. When the molding is completed, the plug 19 is pulled up from the mold 15, and the rotary mold holder 13 makes one eighth rotation. Cooling air is jetted from the air nozzle device 21 to the product 11, and the product 11 is solidified.
At the same time, the next product 11 is molded in the former mold 15 as described above. The product 11 is removed from the mold 15 while being attached to the film 9. At this time, for example, the airtight chamber 14 is set to the atmospheric pressure. Alternatively, compressed air is applied to the airtight chamber 14 to remove it from the mold 15.

The film 9 attached with the products 11, 11, at predetermined intervals is sent to the trimming cutter device 22. The cutter 24 is driven by the plunger 23, and the product 1
1, 11, ... Are separated from the film 9 and fall onto the command bed 2. The film 9 from which the products 11, 11 are separated becomes the end material 9 ′. And immediately the feed roller 2
A roller device 26 composed of 7, a guide roller 28, a pair of drive rollers 29, and the like sends the toner to the supply port 8, mixes it with the resin raw material J, and regenerates the film 9 again. In addition,
The film 9 is intermittently fed to the trimming cutter device 22, but if the end material 9'exiting the trimming cutter device 22 is loosened, the roller device 26 can be continuously driven to rotate. it can.

[0016]

As described above, according to the present invention, since the film material extruded by the extruder is supplied to the vacuum forming machine, the film material is just melted and extruded and is in a relatively high temperature state. , Without adding new heat
The film material can be supplied to the vacuum forming machine only by passing through a cooling step of lowering it to a predetermined temperature. Therefore, according to the present invention, the cost of the vacuum forming apparatus can be reduced, and the energy cost for vacuum forming can be reduced.
Further, according to the present invention, since the returning step for returning the film end material from which the molded product is separated to the supply port of the extruder is provided, the film end material is effectively used and the resin material cost is There is no cost pressure. Therefore, according to the present invention, an effect peculiar to the present invention that a resin molded product can be molded at low cost can be obtained.

[Brief description of drawings]

FIG. 1 is a front view schematically showing an embodiment of the present invention.

FIG. 2 is a front view schematically showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Extruder 5 T die 6 Feeder 9 Film 9'End material 10 Cooling roll 12 Vacuum forming machine 13 Rotary die holder 18 Plug assist device 19 Plug 22 Trimming cutter device 26 Roller device

Claims (3)

[Claims] 1. A manufacturing process of supplying a synthetic resin J to an extruder 1 to manufacture a film material 9 by the extruder 1, and a cooling process of lowering the film material 9 manufactured in the manufacturing process to a predetermined temperature. The film material 9 lowered to a predetermined temperature in the cooling step is supplied to the vacuum forming machine 12, and the formed product 11 is formed.
Is separated from the film material 9 and a return step of returning the film end material 9 ′ from which the molded product 11 has been separated in the molding separation step to the supply port 8 of the extruder 1. Continuous vacuum forming method. 2. The resin supply means 7, 8 for supplying the synthetic resin J to the extruder 1 and the synthetic resin supplied from the resin supply means are kneaded and melted to form the film material 9 from the flat die 5.
Extruder 1 for extrusion and film material 9 for extrusion
A cooling means 10 for cooling the mold to a predetermined temperature, and a plurality of molds 1.
A vacuum forming machine 12 having 5, 15 and a plug 19, a die 22 for separating the molded product 11 molded by the vacuum molding machine, and a film end material 9 ′ from which the molded product is separated are used as the resin supply means. A vacuum forming apparatus comprising conveying means 27 to 29 for continuously returning. 3. The vacuum forming machine according to claim 2, further comprising a rotating body 13 which is rotationally driven at a predetermined speed, and a plurality of molds 15 and 15 which are arranged on the outer peripheral portion of the rotating body at substantially equal intervals. A vacuum forming apparatus comprising at least one plug 19 provided corresponding to the mold of the rotating body, and vacuum means which acts from the outside of the mold to make a negative pressure inside the mold.