JPH0252620B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a method for sequentially cutting a tube film of thermoplastic synthetic resin or the like that is intermittently supplied in a flat folded state into a predetermined length. The present invention relates to a bag making device which sequentially forms (bag making) bags with a bottom by welding one end side of the tube film, and which sequentially stacks a predetermined number of the formed bags.

BACKGROUND TECHNOLOGY AND PROBLEMS As is well known, when bottomed bags are cut out one by one from tube film (bag making), when the bags are transported to the next process work location, etc. It is preferable to stack and transport a predetermined number of sheets. However, conventional bag-making equipment for this type of bag did not have a stacking function for sequentially formed bags, so conventionally, the sequentially formed bags were stacked one by one manually by an operator. It was stuck. Moreover, in order to prevent the welded parts of the stacked bags from coming into contact with each other and sticking to each other, a dusting agent such as corn starch is actually sprayed onto the surface of each stacked bag. Therefore, stacking the bags was really hard work.

Therefore, the applicant of the present invention first applied for an invention (Japanese Patent Application No. 57-9226) that can automatically stack bags. This prior invention provides a means for intermittently transporting a tube film vertically downward, and a cutting means for cutting the tube film and welding the upper side of the cut position of the tube film while the transfer of the tube film is stopped. a welding means; a means for sequentially stacking and holding the bottomed bags formed by the cutting in the vertical state at the cut positions; This bag making device is equipped with a means for simultaneously grasping all the stacked bags and transferring them to the next process when the bags are cut, and the bags that are formed one after another are automatically held in a vertical position at the cutting position. It is a very effective invention as it can be stacked on top of each other.

However, in this prior invention, it was found that when the bag forming (bag making) cycle was increased to about 1 second, the welded parts of the bags that were stacked one after another came into contact with each other and tended to stick to each other. .

That is, since the length of the bags that are sequentially formed is constant, the welded portions that are uniformly formed at the lower ends of each bag are all located at the same height. On the other hand, as soon as the welding is completed, the bags are stacked one after another within a very short period of about one second, so that the welded parts of the bags come into contact with each other in a sticky state.

If the bags are stacked with the welded parts stuck to each other, when the stacked bags are taken out one by one and the contents are filled into each bag, the bags will be stacked. Two to three bags, or in severe cases, many bags may be taken out at once while remaining stuck to each other. Therefore, it is difficult to accurately take out the bags one by one, resulting in an inconvenience that greatly confuses the filling operation.

Note that if the bag forming cycle is reduced (delayed) to a few seconds, the welded parts of stacked bags will not stick together even if they come into contact with each other, but this will reduce bag production efficiency. This will result in defects.

OBJECTS OF THE INVENTION The present invention aims to provide a bag making device capable of correcting the defects of the prior invention as described above.

Summary of the Invention The present invention provides means for intermittently transporting a tube film vertically downward, cutting the tube film while the transfer of the tube film is stopped, and welding the upper side of the cut position of the tube film. A cutting means, a welding means, and a means for sequentially stacking and holding the bottomed bags formed by the cutting in the vertical state at the cut positions are provided, and the tube film is transferred by the transferring means. A bag making apparatus configured to sequentially shift the welding positions of the bags formed sequentially and stack them by sequentially varying the intermittent transfer length, the welding portion of the bags being sequentially formed and stacked. You can get something that will not accidentally stick together.

Embodiment Hereinafter, an embodiment of a bag making apparatus to which the present invention is applied will be described based on the drawings.

First, the bag-making apparatus is for forming (bag-making) a bottomed bag 1 made of thermoplastic synthetic resin film as shown in FIG. Both ends 2
Of a and 2b, the lower end 2b side is sealed by welding 3 along the cut surface. Note that, for example, a pair of through holes 4 are bored on the open end 2a side, which is the upper end. Further, the cut surfaces of both ends 2a and 2b are formed in an arc shape. In addition, when this bag 1 is used for shrink packaging of foodstuffs, for example, a heat-shrinkable synthetic resin film such as vinylidene chloride, vinyl chloride, or the like is used. Then, the contents such as foodstuffs are placed in the bag 1, the open end 2a of the bag 1 is squeezed to remove the air inside, the open end 2a is sealed with metal fittings, etc., and the bag 1 is heated. is heat-shrinked and adheres to the surface of the contents. In particular, the bag 1 made of vinylidene chloride film has extremely low gas permeability compared to other films, so it is convenient for packaging foodstuffs and the like.

Next, the outline of the process of forming the bag 1 (bag making) using this bag making apparatus will be explained with reference to FIGS. 2 and 3.

First, the tube film 2 is folded into a flat state and wound into a roll, and the tube film 2 is rolled into one bag 1 from the film roll 6 by a pair of pinch rolls 7, etc., which are intermittent transfer means. It is intermittently pulled out one by one. Although not shown, a plurality of pinch rolls 7 are actually provided on the tube film 2 extraction path, and the tube film 2 is intermittently pulled out by the intermittent rotation of these rollers.

The pulled-out tube film 2 is transferred vertically downward from the pinch roll 7 and supplied to a cutting and welding device 8, which will be described later, where the tube film 2 is cut and welded to form the bag 1 ( bag making).

At the cut position, the bags 1 are sequentially stacked horizontally while remaining vertically by a bag stacking device 9, which will be described later.

When a predetermined number of bags 1, such as 30 to 100 bags, are stacked in the bag stacking device 9, all the stacked bags 1 are gripped at the same time, and a pair of through holes 4 are punched, etc. transferred to the next process.

Next, the structure of the cutting and welding device 8 and the bag stacking device 9 will be explained with reference to FIGS. 4 to 6.

First, a cutting and welding device 8 is placed below both pinch rolls 7, and a bag stacking device 9 is further placed below that. These devices 8 and 9 are each divided into two parts, and are placed opposite to each other on both sides of the tube film 2 which is conveyed vertically downward from both pinch rolls 7. That is, the cutting and welding device 8 includes a pair of film pressers 13.
a, 13b, a pair of hot plates 14a, 14b which are welding means arranged below, and one hot plate 1.
A cutter 1 which is a cutting means arranged at the lower part of 4a
5 and 6, and these are shown in Figures 5 and 6.
As shown in the figure, they are formed into circular arc shapes with the same curvature. One of the hot plates 14a is fixed to a reciprocating member 16 which is driven to reciprocate in the directions of arrows a and b in FIG. 4 by a drive device not shown, and is configured to reciprocate integrally with the reciprocating member 16. . The cutter 15 is also connected to the reciprocating member 16 by the mounting member 17.
It is configured such that it is integrally coupled with and reciprocated in the same direction. In addition, one film presser 13a
are fixed to the tips of a plurality of holding rods 18 that are slidably held on the reciprocating member 16 in the directions of arrows a and b, and are held by the reciprocating member 16 by a spring 19.
It is energized to protrude in the direction of arrow a with respect to the arrow a. Further, the other film presser 13b and hot plate 14b are fixed at fixed positions. In addition, both film pressers 13
Silicone rubber 2 is placed on the film holding surface of a and 13b.
0a, 20b, etc., and cooling water channels 21a, 21 are installed near each film holding surface.
1b is provided. Also, both hot plates 14a, 14
Heaters 22a and 22b are provided on the heating plates 14b, respectively, and a silicone rubber 2 is provided on the tip of the other heating plate 14b.
3rd class is installed. Further, the tip of the cutter 15 is formed into a wavy blade 24 as shown in FIG. 5, so that the tube film 2 can be easily cut by a push-cut action.

Next, the bag stacking device 9 has a plurality of pins 2 disposed at the bottom of the cutter 15, which are holding means for the bags 1.
6, and a push-out member 27 of the bag 1 disposed opposite to this under the other hot plate 14b. The pins 26 are inserted through a plurality of pin insertion holes 28 provided in the mounting member 17, and their tips are sharply formed. Further, the extrusion member 27 has a plurality of pin insertion holes 2.
9 and an insertion slit 30 for the cutter 15 are provided. and pin 26 and extrusion member 27
are configured to be reciprocated in the directions of arrows a and b in FIG. 4 by drive devices not shown, respectively. The number of pins 26 to be used is selected according to the width of the tube film 2, and three or more pins 26 are used when forming a wide bag 1 from a wide tube film 2.

Next, the operation of the process of forming the bag 1 (bag making) and the process of stacking the formed bag 1 will be explained with reference to FIGS. 7 to 11.

First, as shown in FIG. 7, with one of the hot plates 14a, the cutter 15, and the pin 26 being moved back in the direction of the arrow b, the cutter 15 is moved against the tip of the hot plate 14a.
The tip of the wavy blade 24 is protruded a predetermined distance _l1 in the direction of arrow a, and the tip of the pin 26 is further protruded a small distance _l2 in the direction of arrow a relative to the tip of the wavy blade 24. Further, in this backward movement state, a gap 31 is formed between both film pressers 13a and 13b.

However, in the levered state, the tube film 2 is inserted through the gap 31 and is intermittently transferred vertically downward from above and stopped, and following this stop, the hot plate 1
4a, the cutter 15, and the pin 26 are simultaneously moved forward in the direction of arrow a in FIG.

Then, as shown in FIG.
A part of the tube film 2 is gripped over its entire width between the silicone rubbers 20a and 20b of the tubes 20a and 13b, and at the same time, the tip of the pin 26 is inserted through the tube film 2. Also at this time pin 26
The cutter 15 acts on the tube film 2 with a time delay corresponding to the distance l ₂ with respect to the tip of the tube, and a part of the tube film 2 is cut over its entire width.

Next, as shown in FIG. 9, the hot plate 14a is continuously moved forward in the direction of the arrow a, and its tip is pressed against the silicone rubber 23 of the hot plate 14b with the tube film 2 sandwiched between the two hot plates 14a and 14b. The upper side of the cut position of the tube film 2 is thermally welded over its entire width. Note that the spring 19 is compressed at this time.

By cutting the tube film 2, a bag 1 with a bottom is formed (bag-making), the lower end of which was thermally welded in the previous thermal welding process. The bag 1 formed by the cutting is inserted into the pin 26 at the cut position and held at that position. Further, the thermal welding is performed with the tension of the tube film 2 temporarily loosened by the cutting, and the upper side of the thermally welded portion is connected to the cooling water channel 2.
1a, 21b, which are configured as cooling members, are effectively cooled, so that the strength of the heat-welded portion of the tube film 2 can be sufficiently increased. i.e. bag 1
It is possible to accurately heat-weld the lower end side to a predetermined welding width. Note that both the heating plates 14a and 14b are replaced with electrodes for high frequency welding, and the tube film 2
can be configured to perform high frequency welding.

Next, as shown in FIG. 10, the hot plate 14a, the cutter 1
5. Pin 26 simultaneously moves back (backwards) in the direction of arrow b
At this time, at the same time as the pin 26 moves backward in the direction of arrow b, or after the pin 26 has finished moving back to the position shown in the figure, that is, following the backward movement of the pin 26, the pushing member 27 moves in the direction of arrow b. The bag 1, which has already been inserted and held by the pin 26, is pushed into the back of the pin 26. After the pushing operation of the bag 1, the push-out member 27 is moved back (backward) in the direction of arrow a to return to its original position.

With the above, one cycle of operation for forming one bag 1 is completed, after which the tube film 2 is intermittently transferred vertically downward again, and the above operation is repeated one after another.

By repeating the above operations, the bags 1 that are successively formed as shown in FIG. 11 are inserted into the pin 26 in a vertical state at the cut position and are stacked one after another. Note that this stacking operation for bag 1 is performed in units of, for example, 30 to 100 sheets.
When a predetermined number of bags 1, for example 50 bags, are stacked,
All the stacked bags 1 are gripped at the same time and transferred to the next process.

As shown in FIGS. 2 and 3, two sets of belt conveyors 34 and 35 are provided on one side and the lower part of the bag stacking device 9. The stacking operation of the bags 1 by the bag stacking device 9 described above is performed with both belt conveyors 34 and 35 being rotated in the directions of arrows c and d in FIG. As a result, as described above, the lower ends of the bags 1 that are sequentially inserted through the pins 26 and stacked come into contact with the belt conveyor 34 and receive a tensile force in the direction of arrow c in FIG. 3, causing each bag 1 to wrinkle. not be,
They are stacked one after another in an orderly manner, each one under tension in the vertical direction. When a predetermined number of bags 1, for example 50 bags 1, have been stacked, all the stacked bags 1 are stacked.
are gripped at the same time, pulled out from the pin 26, and transferred to the next process such as a punching process. At this time, the lower end side of all the bags 1 is placed on the belt conveyor 35 and transferred to the third
Since the bags 1 are smoothly transferred in the direction of the arrow d in the figure, all the bags 1 are quickly taken downward from the stacking position by the bag stacking device 9. At this time, all the bags 1 are received by the bag receiving rod 36, and then transferred horizontally in the direction of the arrow e in FIG. 3 to be transferred to the next process such as a punching process.

In the bag making apparatus of the present invention, as shown in FIG _.
It is configured so that it can be varied alternately between l and ₁₁ .
Note that this movement of varying the transfer length can be performed by controlling the rotational speed or rotation time of the pair of pinch rolls 7 that are intermittently driven to rotate.
Regarding the control of these rotation speeds and rotation times,
Electrically, for example, there is a method of electrically controlling the intermittent drive motors of the pair of pinch rolls 7. Mechanically, for example, there are methods such as interposing a variable angular speed ratio transmission mechanism in the transmission path of the intermittent rotation driving force of the pair of pinch rolls 7, or interposing a transmission having a switching clutch.

According to the bag-making apparatus of the present invention, the intermittent transfer length of the tube film 2 can be adjusted by adjusting the length _l10 and _l11.
Since the structure is configured to alternately change the length of the bag 1, the length of the bag 1 formed sequentially can be changed from large to small as described above.
It is varied alternately between l ₁₀ and l ₁₁ . As a result, steps l ₁₂ corresponding to the difference between the lengths l ₁₀ and l ₁₁ are alternately given to the height of the welded 3 parts of the bags 1 that are sequentially stacked on the bag stacking device 9. There is no problem that the three welded parts come into contact with each other and become stuck to each other.

Modifications Although an embodiment of the present invention has been described above, various modifications can be made based on the technical idea of the present invention.

For example, the transfer means, cutting and welding means, and holding means in the present invention are the pinch roll 1 shown in the embodiment.
7. The cutting and welding device 8 and the bag stacking device 9 are not limited to the above, and various modifications can be made.

Furthermore, regarding sequentially varying the intermittent transfer length of the tube film, in the embodiment, the intermittent transfer length is alternately varied in two steps of large and small lengths, but for example, lengths of three or more steps are changed. It is also possible to construct a structure in which the values are repeatedly varied in sequence.

Further, according to the present invention, it is possible to use an air blower in order to cool down the welded portions of the bags that are successively formed as quickly as possible.

Effects of the Invention The present invention can produce one bag with a bottom from tube film.
Bags that are cut into pieces (bag-making) can be automatically stacked one after another vertically at the cut position, and at the same time,
In particular, since bags can be stacked with a step difference between the welded parts of adjacent bags, there is no problem that the welded parts of the stacked bags may come into contact with each other and become stuck to each other. Does not occur at all. Since the welded parts of the bag do not accidentally stick to each other, the bag forming (bag making) cycle can be easily increased to around 1 second, improving bag production efficiency. At the same time, the quality of the product can be improved.
Furthermore, the structure is very simple, as the object can be achieved by simply sequentially varying the length of the tube film's intermittent transfer by a bag transfer means such as a pinch roll.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a perspective view of a bag formed from a tube film, and Fig. 2 shows feeding of the tube film, formation of the bag, and arrangement of the formed bag. FIG. 3 is a side view of the same as above, FIG. 4 is a vertical cross-sectional view of the tube film cutting, welding and stacking device of the formed bag, and FIG. 5 is the same as above. FIG. 6 is a perspective view showing one side of the device part, FIG. 6 is a perspective view showing the other side of the same device part, and FIGS. 7 to 11 show cutting of tube film, welding, and stacking of formed bags. FIG. 12 is an enlarged vertical cross-sectional view of the main part to explain the bag stacking situation. Also, in the symbols used in the drawings, 1...
Bag, 2...Tube film, 3...Welding, 7...
...Pinch roll, 8...Cutting and welding device, 9...
...Bag stacking device, 14a, 14b...Hot plate, 1
5... cutter, 26... pin, 27... extrusion member.

Claims (1)

[Claims] 1. Means for intermittently transporting the tube film vertically downward, and cutting means and welding means for cutting the tube film and welding the upper side of the cut position of the tube film while the transfer of the tube film is stopped. and a means for sequentially stacking and holding the bottomed bags formed by the cutting in the vertical state at the cut positions, and for intermittent transfer length of the tube film by the transfer means. A bag-making device configured to sequentially vary the welding positions of the bags formed in the above-described sequential manner so that they can be stacked.