JPH0450106Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a method of heat-sealing flat tube bands (including gusset tubes) made of synthetic resin in the transverse direction at predetermined intervals, which are molded by the inflation molding method. The present invention relates to an apparatus for manufacturing a bottom-seal type bag by cutting the vicinity of the heat-sealing member, and particularly relates to a bag-making machine equipped with a welding device for forming the heat-sealing 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 that have a narrow allowable heating temperature for the seal bar, or films made of medium-low pressure or high-pressure polyethylene are used. Conventionally, in these films, the heat-sealed portion is bent in the transport direction due to the tensile force caused by transport after heat welding. This may cause the seal strength of the heat seal part to decrease,
The flat tube band of the heat-sealed portion shrinks in the width direction and becomes 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. Also, depending on the type of cooling device, the uneven thickness of the bag material band and the shape of the gusset part may cause the bag material band to meander during transportation, or the heat seal part may become damaged due to repeated over-relaxation and over-tension. There is a risk of poor fusion.

[Problem to be solved]

This invention provides the market with an apparatus that can manufacture 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

[Means for solving problems]

This device has a receiving roller with a surface elastic layer on the upstream side of a pair of interlocking drive conveyors that sequentially convey bag material strips, and a long line 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 heat 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 seal portion formed by welding by the welding device. In a device in which the conveyor and the receiving roller have the same circumferential speed and are driven synchronously, an air-cooled or water-cooled cooling roller that is very close to the receiving roller and does not contact the receiving roller is connected to the receiving roller. At least one of the cooling rollers is provided in parallel, and a heat dissipating conveyance path for the bag material band is provided on the downstream side from the heat sealer contact position of the receiving roller, around which the bag material band wraps around at least half a circumference, and at least one of the cooling rollers is provided. A bag material strip cooling conveyance path is provided on the circumferential surface of the bag material strip, which further wraps the bag material strip immediately after leaving the receiving roller for about half a circumference or more, and the circumferential speed of the cooling roll is equal to the circumferential speed of the receiving roller. The problem was solved by creating a bag making machine that is completely synchronized using a gear transmission mechanism.

[Embodiment]

This invention will now be explained based on embodiments.

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

Reference numeral 16 denotes one cooling roller provided at a position through which the bag material strip F conveyed from the receiving roller 12 to the conveyor 10 passes, and there is no particular limitation on whether it is an air-cooled type or a water-cooled type.

One of the cooling rollers 16 is connected to the receiving roller 12.
The receiving roller 12 is placed very close to and without contact with the circumferential surface of the receiving roller 12.
The bag material band F guided by the receiving roller 12 is guided by the guide bar or guide roller 17 at a slightly upstream position where it contacts the heat seal bar 13 and comes into contact with the rear receiving roller 12 and is heated. A heat dissipation conveyance path is formed that wraps around the receiving roller 12 in an area of an angle α of approximately half the circumference or more from the contact position of the seal bar 13, and the bag material strip F sent out from the receiving roller 12 passes through the space only in a small section D. ,
Next, a cooling conveyance path is formed around the outer peripheral surface of the cooling roller 16 within an angle β, and the angle β is also approximately half the circumference or more.

The bag material strip F that has left the outer peripheral surface of the cooling roller 16 passes through a suitable guide roller 18 and is transferred to the conveyor 1.
I am guided by 0.

The aforementioned receiving roller 12 and cooling roller 16 have the same circumferential speed, and are connected to each other so as to operate completely synchronously by a transmission mechanism 19 consisting of a gear mechanism.

Effects of Embodiment 1 In this embodiment configured as described above, when the conveyor 10, the receiving roller 12, and the cooling roller 16 are driven synchronously at the same circumferential speed, the bag material strip F is intermittently conveyed by a constant length, and the Each time the welding device 14 stops, welding is performed to form heat-sealed portions S in the transverse direction at intervals of the constant length, and these heat-sealed portions S are sequentially fused to the circumferential surface of the receiving roller 12. It passes through the heat dissipation conveyance path while moving along with the receiving roller 12, or is transferred from the receiving roller 12 to the cooling roller 16 in a somewhat solidified state.
Most of the heat-sealed portion S is absorbed by the cooling roller 16 in the cooling conveyance path that wraps around the outer peripheral surface of the cooling roller 16, and this heat-sealed portion S is solidified and passed through the guide roller 18. The bags are drawn into the conveyor 10 and cut in the transverse direction near the heat-sealed portion S by the cutting device 15 to sequentially manufacture bottom-sealed bags.

In this embodiment, the conveyor 10, the receiving roller 12, and the cooling roller 16 are all transmitted by a transmission mechanism 19 consisting of a gear mechanism and having the same circumferential speed, so they are driven completely in synchronization and at the same speed, and the heat seal bar 13 is positioned at the same position. From, conveyor 10
The bag material band F is conveyed to the position without excessive tension or relaxation.

Embodiment 2 The same reference numerals as in Embodiment 1 represent the same structural parts and members, and provide the same effects.

The difference is that another second cooling roller 20 is provided between the cooling roller 16 and the guide roller 18, and this roller 20 is also very close to the first cooling roller 16 and is not in contact with it. The peripheral speed is the same as that of the other rollers, and these rollers are also connected by a transmission mechanism 19 consisting of the gear mechanism described above.

Therefore, the angle β ₁ of the bag material strip F wrapped around the first cooling roller 16 is much larger than the angle β of embodiment 1, forming a long cooling conveyance path reaching approximately 270°, and Also on the surface of the cooling roller 20 of No. 2, a cooling conveyance path is formed in which the bag material band F is wound around approximately β ₂ =180°. Second cooling roller 2
0 may also be air-cooled or water-cooled.

Further, in this embodiment, the second cooling roller 20
Several guide rollers 18 provided between the conveyor 10 and the conveyor 10 are also driven synchronously at the same circumferential speed by the transmission mechanism 19.

Effects of Embodiment 2 When the apparatus of this embodiment is operated, all the rollers from the receiving roller 12 on which the bag material strip is engaged to the conveyor 10 rotate intermittently at the same circumferential speed and for the same period, and the bag material strip in this process The heat-sealed portion S, which is formed by transporting the bag material F without excessive relaxation or excessive tension, and welding the bag material band F on the receiving roller 12 with the heat-sealing bar 12 as in the first embodiment, is attached to the receiving roller 1.
After being almost solidified on the second and first cooling rollers 16, it is further transferred to the second cooling roller, sent to the circumferential surface of the second cooling roller, where heat is taken away, and almost completely solidified and transferred to the conveyor 10. be drawn into.

The above-mentioned cooling rollers 16 and 20 may be water-cooled, but since they have large inertia and require a large control means during intermittent operation, they are preferably air-cooled, and are hollow rollers connected to a blower so as to forcibly supply outside air inside. Alternatively, it is preferable (not shown) to open both ends of the hollow roller and attach an axial type or centrifugal type blower blade 21 to one or both ends of the hollow roller to rotate together with the hollow roller (see FIG. 3).

〔effect〕

In this device constructed and operated as described above, the bag material band F is conveyed in a state wrapped around the receiving roller 12 and the cooling roller 16 or the cooling rollers 16 and 20, so that the surface of the receiving roller 12 and Contact friction force with bag material band F and cooling roller 1
Due to the contact friction force between 6 or 16 and 20 and the bag material band F, both are conveyed in an integrated state, and the elongation or contraction of the heat-sealed portion S of the manufactured bag also increases the length in the width direction of the bag material band F. Also, the receiving roller 12 and the cooling roller 16 or 16
and 20 are non-contact, completely synchronized and at the same speed, intermittent forced drive, so that while the bag material strips are sequentially transferred and conveyed through these rollers, the bag material strip F is neither over-relaxed nor over-stressed. Moreover, since they are not in contact with each other, even if the bag material strips F have uneven thickness or gussets, there is almost no risk that the bag material strips will be conveyed in a meandering manner. It solidifies in a stable state, this part does not distort, the sealing strength is improved, and the appearance is beautiful.

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/min over a wide range of 300℃, and compared to conventional methods, the allowable heating temperature range and efficiency are both more than double.

Furthermore, it is possible to easily process nylon-polyethylene bonded films, which were conventionally considered difficult to process, as well as medium-low pressure 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 conventional method.

When the cooling roller 16 or both 16 and 20 are water-cooled, the cooling effect is excellent. On the other hand, when these are air-cooled, they are lightweight, the inertial force at the time of starting and stopping during intermittent operation is small, and movement control is easy, there is little vibration of the device, and there is extremely little risk of causing excessive tension and relaxation to the bag material band F. , the equipment is also simplified.

In the second embodiment, there is one cooling roller.
6 and 20 are provided in sequence, and the bag material belt F that has left the receiving roller 12 is wound around and engaged with these in sequence, and a cooling conveyance path is provided, so that the bag material belt F can be stabilized for a longer time. Since the heat-sealed portion S is held in a stable state, the heat-sealed portion S can be solidified in a more stable state, and its strength and appearance are improved.

[Brief explanation of the drawing]

The drawings show things related to this invention, in which Fig. 1 is a side view showing the principle mechanism of the first embodiment, Fig. 2 is a side view showing the principle mechanism of the second embodiment, and Fig. 3 is a side view showing the principle mechanism of the second embodiment. The figure is a longitudinal sectional front view showing an example of the cooling roller, and a perspective view showing a part of the bag material band shown in FIG. 4. Symbols in the figure: 10... Conveyor, 11... Elastic layer, 12... Receiving roller, 13... Heat seal bar, 16, 20... Cooling roller, 19... Transmission mechanism, F... Bag material band.

Claims (1)

[Claims for Utility Model Registration] A pair of intermittent drive conveyors of a pair of sandwiching type that sequentially convey bag material strips are provided with a receiving roller having a surface elastic layer on the upstream side and a receiving roller that approaches and separates from the receiving roller each time the conveyor stops. A welding device consisting of a long heat seal bar is provided on the bus bar, and on the downstream side of the conveyor, the bag material strip in the vicinity of the heat seal portion welded by the welding device is transversely A cutting device is provided to cut the conveyor, and the conveyor and the receiving roller have the same circumferential speed and are driven synchronously. At least one bag material strip heat dissipation conveyance path is provided in parallel with the receiving roller, and the bag material strip is wound around at least half a circumference downstream from the heat sealer contact position of the receiving roller, and one of the cooling rollers is provided. A bag material strip cooling conveyance path is provided on at least one circumferential surface of the bag material strip, which further wraps the bag material strip immediately after leaving the receiving roller for approximately half a turn or more, and the circumferential speed of the cooling roll is equal to the circumferential speed of the receiving roller. A bag making machine characterized by being completely synchronized by a gear transmission mechanism.