JP2004338362A - Heat seal bar for standing pouch and bag manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a liquid stored content from leaching by preventing air bubbles from remaining during heat sealing in the boundary between the side part in the heat sealed part of a bottom part and the heat sealed part of the side edge part in a standing pouch. <P>SOLUTION: A bag manufacturing apparatus for the standing pouch is used, in which in a heat seal bar for the side edge part of the apparatus, a heat seal bar having a curved face cross-section of a heat seal face, and a heat seal bar which is a rectangular parallelepiped whose cross-section is approximately a rectangle and having a beveled corner part of the heat seal face are assembled in this order as a side seal tool, and in addition, a bottom cooling member cools the bottom part from the boundary between the side part in the heat seal part of the bottom part and the heat seal part of the side edge part. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat sealing bar for a standing pouch and a bag making apparatus for the standing pouch, and more particularly, to a specific heat sealing bar that does not leave air bubbles in a side seal portion of the standing pouch, and a specific heat combining the same. The present invention relates to a sealing device or a bagging device for a standing pouch having a specific bottom cooling member.

  Standing pouches (self-standing bags) in plastic containers have traditionally been used for packaging food and daily necessities due to their ease of molding and economy, ease of loading and unloading of contents, and convenience of product display due to their self-sustaining nature. Although it is widely used as a container, recently, it has been particularly used as a refillable simple container because of repeated use of a plastic container from the viewpoint of resource saving and environmental protection.

Standing pouches are usually loaded with the bottom of a plastic sheet folded in the center at the bottom of a body made of two plastic sheets, front and back, and heated by a sealing bar on the side and bottom that become the bag. It is manufactured by heat sealing, but due to its importance as a packaging container, improvements can be made from various viewpoints such as the economics of manufacturing, the strength of the heat seal part, etc., the ease of use by consumers, and the storage stability of stored items. It is being done.
As mentioned above, standing pouches are widely used as refillable simple containers, especially for the reuse of plastic container bodies in products such as liquid detergents, edible oils, liquid soaps and shampoos. If the container leaks from the heat seal part or the container is damaged by the impact of dropping from the display shelf and the liquid is scattered, it will be a serious problem as a product, so the strength and sealability of the heat seal will be improved. This is an important issue for standing pouches.

  In order to improve the strength and sealing properties of the heat seal in a standing pouch, many improved techniques have been disclosed before, and as typical examples, a low-density polyethylene film and a polyolefin film having a specific orientation and a specific Using a laminated film made of a polyamide film with a degree of orientation to increase the seal stability and heat seal strength against environmental stress cracking (see Patent Document 1), the bottom seal portion and the side having a step in the film thickness The seal thickness in the vicinity of the side seal portion is reduced to prevent the seal from retreating (see Patent Document 2), and the seal strength is increased by using a specific metallocene catalyst-based polyolefin film (Patent Document 3). See, for example).

JP-A-5-278747 (abstract) JP-A-2000-309346 (abstract) JP-A-2002-127333 (Claim 1 of the abstract and claims)

The above-mentioned improved technology is an excellent technology for improving the strength and sealing property of the heat seal in the standing pouch, but more recently, in the heat seal portion of the standing pouch, the content of the stored contents due to the residual air bubbles at the time of heat sealing is improved. A new problem of leaching was recognized.
This is because, at the boundary between the side portion of the bottom heat seal portion and the side heat seal portion, a step having a thickness of two films occurs, and the heat seal bar is used to weld the seal portion. If the pressure and heat cannot completely absorb the effects of the minute gap due to the step, the air bubbles are caused to be heat-sealed in a state where very small bubbles are sealed.

In particular, when the storage material of the standing pouch contains a surfactant such as a liquid detergent, the surfactant slightly wets the heat-sealed portion due to its unique property, and promotes environmental stress cracking. . Normally, sufficient heat-sealing strength prevents further wetting, but if such bubbles remain in the heat-sealed part, if the wetting reaches the remaining bubbles, the heat will be applied at once. There is a concern that the peeling of the seal portion will proceed and eventually the stored liquid will leak.
When such a situation occurs, the contents of the standing pouch become a serious problem in products such as a liquid detergent. Various investigations and experiments were conducted on heat sealing conditions, heat sealing bars, etc., in order to find a method of preventing bubbles from remaining during heat sealing in the vicinity of the boundary between the portion and the heat sealing portion on the side.

  As a result, the present inventors have found a possible solution, and the present applicant has filed an earlier invention for the present invention (Japanese Patent Application No. 2003-40573). The gist of the invention is that the bottom of a plastic sheet folded at the center is inserted into the lower part of a body made of two front and back plastic sheets, and heating is performed on the side and bottom portions that become the bag body. In a bag making machine that manufactures a standing pouch by heat-sealing with a sealed bar, when at least two adjacent pouches are heat-sealed at the same time, the portion that comes into contact with the bottom of the pouch is shallow and rises to the side. For a heat seal bar with a curved heat seal surface, the trapezoid of the heat seal bar located between adjacent pouches The center of the tip, but to discharge the remaining air bubbles therefrom to form a slit.

  According to the invention of the prior application, the above-described remaining air bubbles at the time of heat sealing near the boundary between the side portion and the side heat sealing portion in the bottom heat sealing portion can be sufficiently prevented by a unique device. Although it is a thing, liquid detergents etc. are used as a simple container for refilling a standing pouch, and the surfactant which is a component of the detergent is very slightly wet in the heat seal part due to its unique property. Therefore, in order to ensure sufficient safety in products such as liquid detergents, the present inventors have recognized that it is a problem to be solved by the present invention to more thoroughly prevent the residual air bubbles during such heat sealing. After that, he continued his thoughts and pursued experimental investigation and search for a new method that could more thoroughly prevent the residual air bubbles, Thus, the invention can be said to be the second invention, and it is possible to more thoroughly prevent the residual air bubbles at the time of heat sealing, and to discover and create the present invention which can make a great contribution to the development of the standing pouch technology. Was.

The present inventors loaded a bottom material of a plastic sheet folded at a central portion into a lower portion of a body member formed of two front and back plastic sheets, and heated a side bar and a bottom portion serving as a bag by a seal bar heated at a bottom portion. In an apparatus for manufacturing a standing pouch by heat sealing, when heat sealing at least two adjacent pouches at the same time, the aim is to further completely prevent the above-mentioned air bubbles from remaining at the time of heat sealing. After repeated examinations and experimental studies on the sealing conditions, heat seal bar, cooling member, and the entire bag making device, it is possible to find new countermeasures based on experimental data described later. Thus, the invention of the present application could be created.
Its main features consist of the cross-sectional shape of the heat seal bar at the seal and its combination. In addition, the pressurization method at the heat seal surface, the length of the heat seal surface, and the device for the bottom (bottom) cooling member Is also a major feature.

In the above, the present invention has been described in overview with respect to the background of the creation of the present invention and the basic configuration of the present invention. The invention of [1] is a basic invention, and the following inventions embody the basic invention, make it an embodiment, or apply it. (Note that the entire invention group is collectively referred to as "the present invention.")
[1] A heat seal bar of a standing pouch bag making apparatus, wherein the heat seal bar is a rectangular parallelepiped having a substantially rectangular cross section, and a corner of a heat seal surface is chamfered.
[2] The heat seal bar according to [1], further comprising a projecting heat seal bar branched from substantially the center in the length direction of the side surface of the heat seal bar.
[3] The heat seal bar according to [1] or [2], wherein the heat seal bar is a side seal device.
[4] A bag making apparatus for a standing pouch, wherein the heat seal bar according to [1] or [2] is incorporated as a side seal tool.
[5] A heat seal bar having a cross section of a heat seal surface having a curved surface, and a heat seal bar in [1] or [2], which are incorporated as side seal tools in this order, and a bottom seal tool, a cooling member, and a bottom material film. A bag making apparatus for a standing pouch, comprising a folding member.
[6] The bag making apparatus for a standing pouch according to [4] or [5], further comprising a set of three side seals behind the heat seal bar according to [1] or [2]. .
[7] The bag-making bag for a standing pouch according to [6], wherein the set of three side seals comprises a protruding heat seal bar branched from substantially the center in the longitudinal direction of the side surface of the heat seal bar. apparatus.
[8] The centroid of the heat seal bar having the projecting heat seal bar branched from substantially the center in the longitudinal direction of the side surface of the heat seal bar is aligned with the center of pressurization of the seal unit. ], A bag making device for a standing pouch.
[9] The bag making apparatus for a standing pouch according to any one of [4] to [7], wherein the length of each heat seal bar is shorter than the height of the pouch.
[10] The bottom cooling member cools the bottom (bottom) from the boundary between the side portion and the side heat seal portion in the bottom heat seal portion, [4] to [8]. A bag making device for a standing pouch according to any of the above.
[11] The bag making apparatus for a standing pouch according to [10], wherein the bottom cooling member is a substantially rectangular plate.

In the standing pouch, the side portion of the bottom material becomes four films, the side portion in the vicinity thereof becomes two films, and the side portion in the bottom heat seal portion and the heat seal portion in the side portion are formed. Even if there is a step with a thickness of two films near the boundary with the part, heat sealing is not performed in a state where very small air bubbles are trapped, and heat near the boundary It is possible to prevent minute bubbles from remaining in the seal portion.
As a result, even if the standing pouch is used as a simple container for refilling a liquid detergent or the like, there is no danger of leakage of the liquid detergent or the like due to the wetting of the heat seal portion by the surfactant of the liquid detergent component.

The invention of the present application has been described above as a means for solving the problems along the basic configuration of the present invention. Hereinafter, the embodiments of the invention of the present invention will be described with reference to the drawings. The details will be described in detail.
As described above, the present invention relates to a heat sealing bar for a standing pouch, a bottom cooling member, and a standing pouch bag making apparatus including the same. Specifically, the present invention relates to a specific method for preventing air bubbles from remaining in a side seal portion of a standing pouch. The present invention relates to a heat seal bar, a specific heat seal device combined therewith, a bottom cooling member, and a bag making apparatus for a standing pouch having the same, and furthermore, heat in a side of the standing pouch that does not leave air bubbles in the side seal portion. The sealing method is also inherent.

(1) Standing pouch and bag making device for standing pouch
The standing pouch (self-supporting bag) per se according to the present invention is generally known, and a typical standing pouch is schematically illustrated in FIG. 1 as an example as a front view.
In the standing pouch, the bottom of a plastic sheet folded at the center is inserted into the lower part of the body consisting of two front and back plastic sheets, and heat-sealed with a seal bar heated at the side and bottom of the bag. The standing pouch 10 includes a bottom member 11 and a body member 12, and an outlet 13 for stored items is provided on the upper side. The bottom material is heat-sealed at a curved heat-sealing portion 14 having a shallow portion that comes into contact with the bottom and rising to the side surface, and the body material is heat-sealed at a side portion 15.
Then, the side portion of the bottom material becomes four films, and the side portion in the vicinity thereof becomes two films. Therefore, the side portion in the bottom heat seal portion and the heat seal portion in the side portion are formed. In the boundary of the above, when a step of the thickness of two films is generated, and the pressure and heat when welding the seal portion by the heat seal bar cannot completely absorb the influence of the minute gap due to this step, Heat sealing is performed in a state where very small air bubbles are sealed in the vicinity portion 16, and fine air bubbles remain.

Both the raw material resin and the thickness or dimensional length of the film of the body material and the bottom material are arbitrary, but polyethylene or ethylene-propylene copolymer which is rich in heat sealability as the inner layer and printability and the like as the outer layer. A composite film using a polyamide or polyester having a high gas shielding property is preferable. Typically, an inner layer film of a linear low density polyethylene (LLDPE) having a thickness of about 130 μm and an outer layer film of a stretched polyamide having a thickness of about 15 μm are provided. The laminated film by dry lamination is used. An intermediate layer such as a gas barrier resin layer or a thin aluminum vapor deposition layer may be interposed.
Note that the linear low-density polyethylene has high impact resistance, has no chemical action with stored items, and has high rigidity to improve the self-sustainability of the standing pouch. The stretched polyamide is also rich in impact resistance and strength, and improves the standing pouch's self-sustainability due to its high rigidity.

Although a device for making a standing pouch is also used, a typical device is shown in FIG. 2 as a schematic diagram. In the bag making apparatus 20, the bottom material film 22 is sent out from the supply roller 21, is folded in two at the center of the film on the forming plate 23, and is inserted between the ends of the pair of body films 24. In the laminated material of the running body material / folded bottom material / body material, the bottom portion is heat-sealed by the bottom material heat seal bar 25, and the side portion is heat-sealed by the side portion heat seal bar 26. Finally, it is cut into product pouches by a cutter 27. Normally, a bottom (bottom) cooling member is continuously installed on the bottom material heat seal bar 25, and a side (side) cooling member is continuously installed on the side heat seal bar 26, which is clearly shown in FIG.

(2) Shape of Heat Seal Bar In the present invention, five heat seal bars are typically used as bars for performing heat sealing on the side portions in the bag making apparatus for standing pouches. The feature is that one of them is a rectangular parallelepiped whose cross section is substantially rectangular and the corner on the long side of the heat sealing surface is chamfered, and the cross sectional shape is shown in FIG. ing. R of the chamfered portion 31 of the heat seal bar 30 is preferably about 30R. The chamfer amount is about 3-0.15. The heat seal bar is mainly used as a side seal device.
Since the long side corners of the heat sealing surface are chamfered, even when minute air bubbles are caught in the sealing surface when the side edges are heat sealed, the air bubbles are discharged from the gaps in the chamfered portion. . In particular, since the side portion of the bottom member becomes four films and the side portion in the vicinity thereof becomes two films, the side portion of the bottom heat seal portion and the heat seal portion of the side portion are formed. In the boundary of the above, a step of thickness of two films is generated, and even if the pressure and heat when welding the seal portion by the heat seal bar cannot completely absorb the influence of the minute gap due to the step, the minute Even if air bubbles are caught in the sealing surface, the air bubbles are discharged from the gap of the chamfered part, and it is prevented that heat sealing is performed in the state where very small air bubbles are sealed, and fine air bubbles do not remain. Absent.

Typically, when five heat seal bars are used, the other seal bars are preferably one heat seal bar having a heat seal surface having a curved surface of approximately 100R, and one heat seal bar side surface. A combination of three sets of deformed heat seal bars having a protruding heat seal bar branched at a substantially central portion in the length direction is used. Each seal bar is shown at 32 and 33 in FIG.
In the set of three deformed heat seal bars, a protruding heat seal bar is provided to simultaneously heat seal the outlets of the stored items of each pouch when heat sealing at least two adjacent pouches at the same time. And its shape is illustrated in FIG. Therefore, the heat seal bar is called a deformed heat seal bar.

(3) Combination order of five heat seal bars The combination order of five heat seal bars is such that the cross section of the heat seal surface has a curved surface when viewed from the film supply direction in the bag making apparatus, and the cross section is substantially the same. A heat seal bar, which is a rectangular parallelepiped and has a chamfered corner on the long side of the heat seal surface, and a set of three deformed heat seal bars are assembled as side seal tools in this order.
This combination order is very important in the present invention, and is surprisingly, for example, a heat seal in which the cross section is a substantially rectangular parallelepiped and the long side corner of the heat seal surface is chamfered. Even if the bar is appropriately used alone, or if the combination or arrangement order of the above-mentioned five seal bars is changed, the boundary between the side portion of the bottom heat seal portion and the side heat seal portion is changed. In the vicinity, when minute bubbles are caught in the sealing surface, it is not prevented that heat sealing is performed in a state where very small bubbles are sealed, and minute bubbles may remain. This is clearly shown in Table 1 showing data in the examples described later.
The order of combination of the five heat seal bars is shown as a side seal (five stages) in FIG. 6. Also shown are the bottom seal and the cooling member associated with each seal.
The heat seal bar, which is a rectangular parallelepiped having a substantially rectangular cross section and having a chamfered corner on the long side of the heat seal surface, is a protruding heat seal branched to a substantially central portion in the length direction of the heat seal bar side surface. A modified heat seal bar having a bar may also be used. Further, the three-stage deformed heat seal bar in the latter stage may be chamfered at the corner on the long side.

(4) Other requirements for the heat seal bar The cross-sectional shape of the heat seal bar and the combination and order of the five heat seal bars in the present invention are determined by the side portion and the side portion in the bottom heat seal portion. In the vicinity of the boundary with the heat seal part, it is a basic requirement to prevent heat bubbles in a state where air bubbles are sealed and to prevent micro bubbles from remaining. Additionally, the center of pressure of the seal unit and the centroid of the seal surface of the seal portion in the deformed heat seal bar are further aligned, and the length of each of the five seal bars is made shorter than the pouch height. The two requirements also have an additive effect in preventing bubble entrapment and microbubble retention near the above boundaries.

The requirement for aligning the center of pressure of the seal unit with the center of the sealing portion of the deformed heat seal bar is schematically illustrated in FIG. 4, and [1] in FIG.
0 indicates that the center of pressure 41 is not aligned with the center of pressurization 42, and [2] in FIG. It shows the state that it is doing. Note that, as described above, the projection 43 near the center is a projection-like heat seal bar for simultaneously performing heat sealing of the outlets of the stored items of each pouch when heat sealing at least two adjacent pouches at the same time. It is.
When the center of pressure of the seal unit is aligned with the centroid of the seal surface of the seal portion, the pressure applied to the seal surface by the seal bar becomes uniform, and the air bubbles are smoothly discharged during heat sealing.

The requirement that the length of each heat seal bar be shorter than the height of the pouch is schematically illustrated in FIG. 5, where both ends of the heat seal bar 50 have side portions in the bottom heat seal portion and side edges. A state is shown in which heat sealing is performed over two portions 51 near the boundary between the portion and the heat sealing portion.
In particular, in the case of a multi-stage seal, usually, the length of each heat seal bar is longer than the height of the pouch, and if this is shortened, the pressurized area at the time of heat seal is reduced, and as a result, the load per unit area is increased. The pressure increases, and the remaining air bubbles are easily discharged. Further, since both ends of the heat seal bar extend to two places near the boundary 51, bubbles near the boundary are easily discharged. In this case, the pouch height refers to the length of a pair.

(5) Heat sealing conditions Normal heat sealing conditions are appropriately adopted. For example, the heat sealing temperature is about 160 to 240 ° C., and the time is about 0.3 to 0.6 seconds.

(6) Bottom (Bottom) Cooling Member In the present invention, another configuration effective for preventing the entrapment of microbubbles is provided. It is a new device in the bottom cooling member and is disclosed in the invention units [10] and [11] in paragraph 0011, and the bottom cooling member is provided with the side portion and the side portion in the bottom heat seal portion. It is characterized in that the bottom (bottom) from the boundary with the heat seal portion is cooled, and the bottom cooling member is preferably a substantially rectangular plate-like body.

As described above in paragraph 0016, this bottom cooling member is installed continuously to the bottom material heat seal bar 25, and constitutes a cooling unit of the standing pouch bag making apparatus of the present invention. Is illustrated.
More specifically, this is schematically shown in FIG. 7 as a schematic diagram, and [1] in the figure shows a conventional example, in which the bottom cooling member 70 is the whole heat sealing portion 72 at the bottom of the standing pouch 71. , And a state in which the side portion near the bottom portion and the entire body portion 73 near the bottom portion are covered and cooled.
As described above, the side portion of the bottom member is formed of four films, and the side portion in the vicinity thereof is formed of two films. Therefore, the side portion of the bottom heat seal portion and the heat portion of the side portion are formed. At the boundary with the seal portion, a step having a thickness of two films occurs, and the pressure and heat when the seal portion is welded by the heat seal bar cannot completely absorb the effect of the minute gap due to the step. When the air bubbles are caught in the sealing surface, the portion is cooled by contacting the bottom cooling member as it is, so that the resin material is cooled and the flexibility is reduced, and fine air bubbles are discharged from the heat seal portion to the outside, It becomes more difficult to be discharged.

  [2] in FIG. 7 shows a state of cooling by the bottom cooling member of the present invention, in which the bottom cooling member is located at the bottom (bottom) from the boundary between the side portion and the side heat sealing portion in the bottom heat sealing portion. ) Is cooled, and the bottom cooling member does not cool by contacting the above-mentioned stepped portion, so that the resin material in that portion is not cooled and has high flexibility. It is easy to be discharged outside from the heat seal part.

In the bag making apparatus for a standing pouch according to the present invention, the bottom seal and the bottom cooling are performed in, for example, 3 to 5 sets (stages) in order to enhance productivity, and the bottom cooling state in the case of 3 sets is shown in FIG. ing. In the figure, [1] shows a conventional example, and [2] shows a bottom cooling state of the present invention.
Although the bottom cooling member 80 cools the bottom heat seal portion 81 of the standing pouch, the bottom cooling state of the present invention in [2] is different from the conventional example in [1], unlike the conventional example in [1]. The four portions of the film and the two films on the side portions in the vicinity thereof, the side portion of the bottom heat seal portion and the vicinity of the boundary between the side portion heat seal portion, It is clearly shown that cooling is performed while avoiding the stepped portion 82 having a thickness of two films.

Hereinafter, the present invention will be described in more detail with reference to the drawings in comparison with comparative examples with reference to examples, but it is obvious that the present invention is not limited to the following examples. .
[Explanation of the embodiment with reference to the drawings]
An example of a standing pouch according to the present invention is shown in FIG. 1 as a schematic front sectional view, which is commonly known. The standing pouch 10 includes a bottom member 11 and a body member 12, and an outlet 13 for stored items is provided on an upper side. The bottom material is heat-sealed at a curved heat-sealing portion 14 having a shallow portion that comes into contact with the bottom and rising to the side surface, and the body material is heat-sealed at a side portion 15.

An example of an apparatus for making a standing pouch according to the present invention is shown in FIG. 2 as a schematic side view, which is also commonly used. In the bag making apparatus 20, the bottom material film 22 is sent out from the supply roller 21, is folded in two at the center of the film on the forming plate 23, and is loaded between the end portions (between the upper and lower sides) of the pair of body material films 24. Is done. In the laminated material of the running body material / folded bottom material / body material, the bottom portion is heat-sealed by the bottom material heat seal bar 25, and the side portion is heat-sealed by the side portion heat seal bar 26. Finally, it is cut into product pouches by a cutter 27. A bottom (bottom) cooling member is continuously installed on the bottom material heat seal bar 25, and a side (side) cooling member is continuously installed on the side edge heat seal bar 26.

An embodiment of the heat seal bar according to the present invention is shown in FIG. 3 as a schematic cross-sectional view, in which a cross section is a substantially rectangular parallelepiped, and a long side corner of the heat seal surface is chamfered. In the cross-sectional shape of the seal bar 30, R of the chamfered portion 31 is preferably about 30R.
A heat seal bar 32 having a heat seal surface having a curved surface of approximately 100R and a deformed heat seal bar 33 having a heat seal surface having a substantially rectangular cross section are shown in FIG.

The requirement for aligning the centroid of the part to be sealed in the deformed heat seal bar with the center of pressurization of the seal unit according to the present invention is schematically illustrated in a plan view in FIG. 4, and [1] in FIG. This shows a state in which the centroid 41 of the seal bar 40 is not aligned with the center of pressurization 42, and [2] in the figure indicates that the centroid 44 of the seal bar 40 is not aligned with the center of pressurization 44. This indicates that they are not matched. Note that, as described above, the projection 43 near the center is a projection-like heat seal bar for simultaneously performing heat sealing of the outlets of the stored items of each pouch when heat sealing at least two adjacent pouches at the same time. It is.

The requirement that the length of each seal bar in the five heat seal bars according to the present invention be shorter than the pouch height is schematically illustrated in FIG. 5 as a front cross-sectional view. A state is shown in which heat sealing is performed at two locations near the boundary between the side portion of the bottom heat seal portion and the heat seal portion of the side portion.

The order of combination of the five heat seal bars according to the present invention is illustrated as a side seal (five stages) in FIG. 6 in a schematic plan view. Also shown are the bottom seals and the cooling associated with each seal.
In the embodiment shown in FIG. 6, the cross section of the heat seal surface is approximately 10
In the order of a heat seal bar having a curved surface of 0R, a heat seal bar having a substantially rectangular parallelepiped cross section and a corner on the long side of the heat seal surface being chamfered, and a set of three deformed heat seal bars, Although it is incorporated as a side seal, the second heat seal bar is a rectangular parallelepiped with a substantially rectangular cross section, and the corners on the long side of the heat seal surface are chamfered. A deformed heat seal bar having a protruding heat seal bar branched at a substantially central portion in the longitudinal direction of the side surface is used (corresponding to Example 2 described later).

The cooling state of the bottom cooling member according to the present invention is illustrated in each [2] of FIGS. 7 and 8 in comparison with the conventional example of each [1], and the bottom cooling member is located at the bottom. The bottom part (bottom) from the boundary between the side part and the side part of the heat seal part in the heat seal part is cooled.

[Examples 1-2] and [Comparative Examples 1-3]
As an apparatus for producing a standing pouch according to the present invention, the apparatus shown in FIG. 2 is used, the bottom material film 22 is sent out from the supply roller 21, and folded at the center of the film on the forming plate 23, In the laminated material of the body material / folded bottom material / body material that is inserted and run between the end portions of the pair of body material films 24, the bottom material heat seal bar 2
5, the bottom portion was heat-sealed, the side edge portion was heat-sealed by a side edge heat seal bar 26, and finally the product was cut into a product pouch by a cutter 27.
As a result, the presence / absence of air bubbles and the state of the air bubbles in the vicinity of the boundary between the side portion of the bottom heat seal portion and the side heat seal portion were observed.
At that time, a laminated film obtained by dry lamination of an inner layer film of linear low density polyethylene (LLDPE) having a thickness of 150 μm and an outer layer film of a stretched polyamide having a thickness of 15 μm was used. The side heat sealing was performed at 200 ° C. for 0.5 seconds.
In addition, the heat seal bar shown in FIG. 3 is a rectangular parallelepiped having a substantially rectangular cross section, and the corner on the long side of the heat seal surface is chamfered (R in the chamfer 31 in the cross sectional shape is 30R; A), a heat seal bar (B in the table; B 'for 30R in the table) having a heat seal surface having a curved surface of approximately 100R, and a deformed heat seal bar having a substantially rectangular cross section of the heat seal surface. Using (C in the table), the order of combination of the five heat seal bars was that shown in FIG. 6 as the side seals (five stages) in the drawing and those obtained by rearranging them. In Example 2, the cross section is a rectangular parallelepiped having a substantially rectangular shape, and the long side of the heat sealing surface is chamfered. A modified heat seal bar A ′ also provided with a projected heat seal bar was used.
Table 1 summarizes the results of the experiments. Tests 3 and 5 in the table correspond to Examples-1 and 2, and tests 1, 2, and 4 are comparative examples. Controls in the table are standard control examples.
S1 to S5 are in the order of S5 to S1 as viewed from the film supply side, and mean each heat seal bar (A, B, C, etc.).
In Example-1, a) a continuous 50 shot permeate test b) a drop test (20 bags of storage at 5 ° C.) c) an ESCR test (65 ° C. withstand pressure, 65 ° C. upright 1 shot each) did not cause any problem.

[Example-3] and [Control example]
The embodiment in which the bottom cooling member cools the bottom (bottom) from the boundary between the side portion and the side heat seal portion in the bottom heat seal portion under the same conditions as in Example-1. 3 and a cooling condition in which the bottom cooling member covers the entire bottom heat seal portion, and the side portion near the bottom portion and the entire body portion near the bottom portion under the same conditions as in Example 1 to perform cooling. And
When 500 standing pouches were produced, no residual air bubbles were observed in Example-3, and only a few "streaks" were slightly observed in the control example.

[Consideration of results of Examples and Comparative Examples]
By comparing each of the above Examples, Comparative Examples, and Control Examples, in the present invention, the side portions and the side portions of the bottom heat seal portion are formed by the unique heat seal bar structure and their arrangement permutations. It is clearly shown that no fine air bubbles remain in the vicinity of the boundary between the side and the heat seal portion.
Also, from the results of Example-3 and the control example, in the present invention, the bottom cooling member is provided at the bottom (bottom) from the boundary between the side portion and the side heat seal portion in the bottom heat seal portion. It has also been clarified that, if the mode of cooling (3) is additionally employed, it can be said that there is little or no microbubbles remaining.

It is the schematic which shows an example of the standing pouch which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows an example of the apparatus which manufactures the standing pouch which concerns on this invention. It is sectional drawing which shows the cross-sectional shape of the heat seal bar which concerns on this invention. It is the schematic which shows typically the requirement which sets the centroid of the part to seal and the center of pressurization of a seal unit in the set of three deformed heat seal bars concerning this invention. It is the schematic which shows typically the requirement that the length of each seal bar in five heat seal bars concerning this invention is shorter than a pouch height. It is a schematic diagram showing the combination order of five heat seal bars concerning the present invention. It is a schematic diagram showing a cooling state of a bottom cooling member concerning the present invention. It is a schematic diagram showing a cooling state of a bottom cooling member concerning the present invention.

Explanation of reference numerals

10: Standing pouch 11: Bottom material 12: Body material 13: Discharge port of stored material 14: Curved heat seal portion 15: Side portion 16: Side portion of bottom heat seal portion and heat seal of side portion 20: Bag-making apparatus 21: Supply roller 22: Bottom film 23: Forming plate 24: Pair of body films 25: Bottom heat seal bar 26: Side heat seal bar 27: Cutter 30: Heat seal bar 31: chamfered part 32: heat seal bar 33: heat seal bar 40: deformed heat seal bar 41: centroid of deformed heat seal bar 42: center of pressure 43: projecting heat seal bar 44: deformed heat seal Bar centroid and center of pressurization 50: heat seal bar 51: side portion at bottom heat seal portion; 70: Bottom cooling member 71: Standing pouch 72: Bottom heat sealing portion 73: Side portion near bottom and entire body portion near bottom 80: Bottom cooling member 81: Bottom Heat seal part 82: Stepped portion due to difference between two films

Claims (11)

A heat seal bar for a bag making apparatus for a standing pouch, wherein the heat seal bar is a rectangular parallelepiped having a substantially rectangular cross section, and a corner of a heat seal surface is chamfered. The heat seal bar according to claim 1, further comprising a projecting heat seal bar branched from substantially the center in the longitudinal direction of the side surface of the heat seal bar. The heat seal bar according to claim 1, wherein the heat seal bar is a side seal device. A bag making apparatus for a standing pouch, wherein the heat seal bar according to claim 1 or 2 is incorporated as a side seal tool. A heat seal bar having a cross section of a heat seal surface having a curved surface, and the heat seal bar according to claim 1 or 2, which is incorporated as a side seal device in order of the bottom seal device, the cooling member, and the bottom material film. A bag making apparatus for a standing pouch, comprising a folding member. The standing pouch according to claim 4 or 5, further comprising a set of three side seals provided behind the heat seal bar according to claim 1 or 2. Bag making equipment. 7. A bag for a standing pouch according to claim 6, wherein the set of three side seals comprises a protruding heat seal bar branched from substantially the center in the longitudinal direction of the side surface of the heat seal bar. apparatus. 8. The heat seal bar provided with a projecting heat seal bar branched from substantially the center in the longitudinal direction of the side surface of the heat seal bar, wherein the centroid of the heat seal bar and the center of pressurization of the seal unit are aligned. Bag making equipment for standing pouches. The standing pouch bag making apparatus according to any one of claims 4 to 7, wherein the length of each heat seal bar is shorter than the pouch height. The bottom cooling member cools a bottom portion (bottom) from a boundary between a side portion and a side heat seal portion of the bottom heat seal portion. A bag making device for a standing pouch described in the above. The bag making apparatus for a standing pouch according to claim 10, wherein the bottom cooling member is a substantially rectangular plate.

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