JPH0450105Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention heat-seals flat tube bands made of synthetic resin molded by the inflation molding method in the transverse direction at predetermined intervals. The present invention relates to an apparatus for manufacturing bottom-seal type bags by cutting the vicinity thereof, and particularly relates to a bag-making machine equipped with a welding device for forming a heat-sealed portion.

[Prior art, problems]

In general, bags for heavy items, items with a lot of moisture, or items that are likely to be soaked in oil are made of thick film, linear polyethylene, or nylon and polyethylene laminated together. Films with a narrow allowable heating temperature range for the seal bar, or films made of medium-low pressure or high-pressure polyethylene are used, but conventionally, with these films, the heat-sealed portion is transported by the tensile force caused by transport after heat welding. The sealing strength of the heat-sealed portion may be reduced, and the flat tube band of the heat-sealed portion may shrink in the width direction and be distorted, resulting in an unsightly appearance. In addition, in the case of a film in which the allowable heating temperature range of the heat seal bar during thermal welding is narrow, even a slight temperature change will cause welding failure.

Therefore, in the past, the operating speed of the bag making machine was reduced, e.g.
Heat welding is carried out at a relatively low temperature with less than 40 bags per minute. However, this method is inefficient and unprofitable. There is also a known device that cools the heat-sealed part by pressing a cooling member against the heat-sealed part immediately after the heat-seal bar is separated from the receiving roller, but this requires a large number of reciprocating mechanisms, which causes vibration and can cause malfunctions. However, the equipment is expensive.

[Problem to be solved]

This invention brings to the market an apparatus that can produce bags with strong sealing strength without narrowing the permissible temperature range when heat-sealing films such as those mentioned above, and without stretching or distorting the heat-sealed part. The purpose is to provide.

[Means for solving problems]

This device has a receiving roller with a surface elastic layer on the upstream side of a pair of sandwiching type intermittent drive conveyor that sequentially conveys bag material strips, and a long heat roller on the generatrix of the receiving roller that comes into contact with and separates from the receiving roller each time the conveyor stops. A welding device consisting of a seal bar is provided, and a cutting device is provided on the downstream side of the conveyor for cutting the bag material strip in the transverse direction near the heat-sealed portion welded by the welding device. In the apparatus in which the conveyor and the receiving roller have the same circumferential speed and are driven synchronously, the receiving roller has a bag material band wrapped around at least half the circumference downstream of the contact position of the heat seal bar on the peripheral surface of the receiving roller. The bag making machine is characterized in that a material belt conveying path is formed, and at least one cooling roller is brought into contact with the peripheral surface of the receiving roller at a portion where the bag material belt is wound around the receiving roller. The problem was solved by

[Embodiment]

This invention will now be explained based on embodiments.

Embodiment 1 As shown in FIG. 1, reference numeral 10 denotes a pair of pinch-type intermittent drive conveyor (including a pair of pinch-type rollers), and an elastic layer (silicon rubber) 11 is provided on the surface on the upstream side. A welding device 14 consisting of a long heat seal bar 13 is provided on the generatrix of the receiving roller 12 and the receiving roller 12 that comes into contact with and separates from the receiving roller 12 each time the conveyor 10 stops, and on the downstream side of the conveyor 10. is the welding device 14
A cutting device 15 is provided for cutting the bag material band F in the transverse direction near the heat-sealed portion S of the bag material band F formed by welding. The structure up to this point is the same as a known bag making machine.

Reference numeral 16 denotes a touch roller, which is brought into contact with the circumferential surface of the receiving roller 12 at a position more than half a turn downstream from the position of the heat seal bar 13;
On the circumferential surface of the receiving roller 12 between the heat seal bar 13 and the touch roller 16, a conveyance path 17 is formed for the bag material band F to be wrapped around the receiving roller 12.

Reference numeral 18 denotes at least one cooling roller (one in Fig. 1), which is usually water-cooled and is always in contact with the circumferential surface of the receiving roller 12 in the portion of the conveyance path 17. A temperature approximately equal to, but slightly higher than, atmospheric temperature is best. This cooling roller 18 is installed around the receiving roller 12.

The bag material strip F that has passed through the touch roller 16 passes through this outside and comes into contact with a part of the circumferential surface of the cooling roller 18 again, and is then guided to the conveyor 10.

Further, in this embodiment, an upstream touch roller 20 that is forcibly driven or rotates around the receiving roller 12 on the upstream side of the heat seal bar 13 is in pressure contact with the upper part of the receiving roller 12, and this roller is guided to the heat seal bar 13. Roller 12 for receiving bag material band F to be removed
It is intended to hold the

Further, an air pipe 21 is provided immediately downstream of the cooling roller 18 and parallel to the cooling roller 18, and a nozzle or slit 22 is provided in this air pipe 21 toward the bag material strip F on the receiving roller 12. A device to blow air may also be added.

Effects of Embodiment 1 When the conveyor 10 is driven intermittently in this embodiment configured as described above, the bag material band F
are intermittently conveyed by a constant length, and each time they stop, they are welded by the welding device 14 to form heat-sealed portions S at intervals of the constant length in the transverse direction, and these heat-sealed portions S are sequentially While being fused to the circumferential surface of the receiving roller 12, it passes through the position of the cooling roller 18 together with the receiving roller 12, and at this time, the heat of these heat-sealed portions S is cooled and solidified by contact with the cooling roller 18.

At this time, if an air blowing device is provided, the air blown out from the device is blown onto the bag material band F, entraining the cold air near the cooling roller 18.

Thereafter, the vicinity of the heat-sealed portion S is sequentially cut by the cutting device 15 on the downstream side of the conveyor 10, as in the case of a normal device, and bags B are sequentially manufactured.

Embodiment 2 This is shown in FIG. 2, where the same reference numerals as in Embodiment 1 are the same structural members or parts, and have the same effects.

The difference is that the cooling rollers 18a, 18b and 2
There are several.

Effects of Embodiment 2 In this embodiment, the cooling rollers 18a, 18b
Since there are two heat-sealed parts S, the heat-sealed parts S contact each other twice in sequence, and solidification occurs rapidly and completely.

Embodiment 3 This is shown in FIG. 3, where the same reference numerals as in Embodiment 1 are the same structural members or parts, and have the same effects.

The difference is that the touch roller 16 also serves as a cooling roller 18, and the heat-sealed portion S, which has been somewhat cooled on the receiving roller 12, is connected to the conveyance path 1.
It is cooled at the end of 7.

Embodiment 4 The same reference numerals as in Embodiment 1 are the same structural members or parts, and have the same effects.

The difference is that the cooling roller 18 can freely approach and separate (see the arrow in the cooling roller 18 in FIG. 1),
The cooling roller 18 comes into contact with the receiving roller 12 after it has stopped, and when the heat-sealed portion S thereon has just passed the position of the cooling roller 18 after the receiving roller 12 starts rotating, the cooling roller 18 separates from the receiving roller 12. In the figure, the cooling roller 1 is rotated only while the receiving roller 12 rotates approximately 20 degrees from the position at each stop.
8 is in contact with the receiving roller 12. Preferably, these actuations are performed by mechanical cams or electromagnetically.

〔effect〕

In this device constructed and operated as described above, since the bag material band F is conveyed in a state wrapped around the receiving roller 12, the contact friction between the surface of the receiving roller 12 and the bag material band causes , both are conveyed in an integrated state, and the heat-sealed portion S of the manufactured bag does not stretch or contract in the width direction or length direction of the bag material band F, and solidifies in that state,
The adhesive strength of this part is improved and the appearance is beautiful.

In particular, the permissible heating temperature of the heat seal bar 13 is widened, and workability is significantly improved.

In the experimental example, the length of one bag was 500 mm, the bag material band F was made of linear polyethylene with a thickness of 50 μm, and the temperature at the tip of the heat seal bar 13 was about 250°C.
It is now possible to process over 80 bags/minute over a wide range of 300℃, and compared to conventional methods, the allowable heating temperature range and efficiency are more than double.

Furthermore, it is possible to easily process nylon-polyethylene bonded films, which were conventionally difficult to process, as well as medium-low and high-pressure polyethylene films. In addition to the above, it goes without saying that thin films can also be sealed in the same way as in the past.

[Effects of embodiment]

In the first embodiment, even after the heat-sealed portion S is cooled by the cooling roller 18, it remains on the surface of the receiving roller 12 for a while, and the bag material band F separated from the receiving roller 12 by the touch roller 16 is again removed. Since it contacts the cooling roller 18, cooling becomes more complete. Furthermore, the space surrounded by the bag material band F above and below the cooling roller 18 and the touch roller 16 is also cooled by the air that comes into contact with the cooling roller 18, making the cooling effect even more remarkable.

In the second embodiment, the cooling roller 18
a and 18b, the cooling effect is remarkable.

In the third embodiment, the touch roller 16
Since the cooling roller 18 and the cooling roller 18 are also used, the structure is simple. In addition, since the bag material band F is wrapped around it, the heat-sealed part S is in contact with it for a long time, so that the cooling is complete.

In the fourth embodiment, the cooling roller 18 is movable toward and away from the cooling roller 18, and comes into contact with the receiving roller 12 after it has stopped, and after the receiving roller 12 starts rotating, the heat-sealed portion S on the cooling roller 18 just touches the cooling roller 18. After passing the position, the receiving roller 1
2, the rotational power of the receiving roller 12 is reduced.

In other cases where the cooling roller 18 is provided in constant contact with the receiving roller 12, the structure is simple.

In addition, in this invention, even if two or more bag material strips F are connected to the welding device 14 equipped with a single cooling roller 18, several sets of welding devices 14 equipped with the cooling roller 18 are provided above and below, and from these welding devices 14 are provided. Even if several strips of bag material strips F to be carried out are guided to the common conveyor 10 and cutting device 15, the invention remains the same. Moreover, even if these devices are installed side by side in one machine frame, there is no difference in this invention.

In each of the above embodiments, in the case where there is an upstream touch roller 20, the tension acting on the bag material band F on the upstream side is applied to the touch roller 2.
0, so there is no risk of stretching the heat-sealed portion S.

Even if other embodiments are used in combination as necessary, the invention remains the same.

[Brief explanation of the drawing]

Fig. 1 is a principle mechanism diagram of Embodiment 1, Fig. 2 is a principle mechanism diagram of Embodiment 2, and Fig. 3 is a principle mechanism diagram of Embodiment 3.
Fig. 4 is a perspective view of the bag. Main symbols in the diagram: 10...conveyor, 11...
Elastic layer, 12... Receiving roller, 13... Heat seal bar, 14... Welding device, 18... Cooling roller, F... Bag material band, S... Heat sealing section.

Claims (1)

[Claims for Utility Model Registration] 1. On the upstream side of a pair of sandwiching type intermittent drive conveyors that sequentially convey bag material strips, there is provided a receiving roller with a surface elastic layer and said receiving roller that approaches and separates from the receiving roller each time said conveyor stops. A welding device comprising a long heat-seal bar is provided on the generatrix of the conveyor, and on the downstream side of the conveyor, the welding device transversely welds the bag material strip near the heat-sealed portion formed by welding. A cutting device is provided to cut the conveyor, the peripheral speed of the conveyor and the receiving roller are equal to each other, and the device drives synchronously, the peripheral surface of the receiving roller has at least half a circumference downstream from the contact position of the heat seal bar. A bag material belt conveyance path is formed in which the bag material belt wraps around the bag material belt, and at least one cooling roller is brought into contact with the peripheral surface of the receiving roller at a portion where the bag material belt is wrapped around the receiving roller. Bag making machine. 2. The bag making machine according to claim 1, wherein the number of cooling rollers is one to three. 3. The cooling roller is connected to the receiving roller,
The bag-making machine according to claim 1, which is a constantly contact type bag-making machine. 4. The bag making machine according to claim 1, wherein the cooling roller contacts the receiving roller only when the heat sealing section passes through this position. 5. The bag making machine according to claim 1, wherein the cooling roller also serves as a touch roll for determining the end of the bag material belt conveyance path.