JP2000335640A - Inner bag for liner and method for filling liquid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and certainly fill a required quantity of liquid into an inner bag for liner and to make such a method applicable to cases wherein a high- temperature liquid is filled into the inner bag, the inner bag is of a straight chain low density polyethylene film excellent in resistivity against pinholes, or the inner bag is for a large-sized liquid container. SOLUTION: A double plastic film bag body having a filling port 3 for filling a liquid therethrough is such that the liquid is filled into the inside of the bag, and an inner bag 1 for liner to be housed in an outer packaging container 5 for which the surface of its outermost films 2a, 2a' are made rough is folded up with its filling port 3 coming to the surface side, and after the inner bag 1 is housed in the outer packaging container 5 with its filling port 3 facing upward, a warmed-up liquid is filled into the bag through the filling port 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inner bag for a liner used as an inner bag for a bag-in-box or a liner for a drum can, and a liquid filling method for filling the inner bag for a liner with a liquid. More particularly, the present invention relates to a liner inner bag and a liquid filling method which can be easily filled with a required amount of liquid, and can be suitably used as an inner bag of a large bag-in-box.

[0002]

2. Description of the Related Art In recent years,
Large liquid transport containers, such as drums and one-ton containers, are used for food-related products such as alcoholic beverages and seasonings, and for industrial chemicals such as detergents. Plastic inner bags are used from the point of view.

When a liquid as a content liquid is filled in a liner inner bag such as a drum liner or a bag-in-box inner bag as described above, the inner bag or the like is filled with the content liquid and placed in an outer container. There is a method and a method of arranging the inner bag in the outer container and then filling the content liquid. In particular, when the filling amount is large, it becomes difficult to put the filled inner bag in the outer container, and such a filling method is a method generally adopted when filling a liquid exceeding 20 liters. is there. In this case, the inner bag is folded compactly in advance for convenience of transportation, and after being stored in the outer container arranged in the filling device in that state, a filling nozzle is connected to a filling port of the inner bag. Then, liquid filling is performed.

However, when the liquid to be filled by such a method is a high-temperature liquid of, for example, about 65 to 85 ° C., the outer surfaces of the inner bags are stuck to each other in the folded portion due to the liquid temperature, resulting in extremely light blocking. May cause

[0005] When such blocking occurs, the inner bag filled in a folded state as described above does not spread any more, and a dead space is generated. As a result, the full capacity of the drum or the bag-in-box is reduced. In some cases, the desired amount could not be filled due to a drastic reduction, which hindered the filling operation.

Therefore, when blocking occurs, the above-mentioned blocking is peeled off by means of, for example, applying vibration to the inner bag to repair the dead space, but in such a case, manual operation is performed. Not only does it cost
This was a factor in lowering work efficiency.

In particular, in recent years, the problem of liquid leakage due to the generation of pinholes due to transport vibrations has necessitated an improvement in pinhole resistance, and a linear low-density polyethylene film having excellent pinhole resistance has been preferably used. It has become so. By the way, such a linear low-density polyethylene film has recently been reduced in density by using a single-site catalyst, and the lowering of the density tends to improve the pinhole resistance and lower the melting point. And, by this lowering of the melting point, the starting temperature of heat sealing becomes lower in the heat sealing at the time of forming the plastic inner bag. For example, if the linear low density polyethylene film has a density of about 0.905, the heat Temperature at which seal strength is developed is about 90 ° C. (1 kg / cm ² ; 90 ° C .: heat seal conditions of 1 second, heat seal strength of about 0.2 kg / 15 mm)
, The range of heat sealing conditions is widened, and the stability and production speed of the seal are improved. However, on the other hand, even at a temperature below 90 ° C., temporary fusion occurs, and blocking tends to occur. Therefore, when the above-described high-temperature filling is performed on the inner bag made of the linear low-density polyethylene film, the spread of the folded inner bag is deteriorated, and there is a tendency that the specified amount cannot be filled. In particular, in the case of an inner bag for a large bag-in-box, such a tendency was conspicuous because the bag was compactly folded during empty bag transport and the contact area between the inner bag films was large even during filling.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is required for an inner bag for a liner and an inner bag for the liner which can easily fill a required amount even when a high-temperature liquid is filled. Provided is a liquid filling method which can easily and surely fill an amount of liquid, and in particular, can easily store the inner bag in an outer container even if the inner bag is for a large liquid container.

[0009]

In order to achieve the above object, the present invention provides (1) a single or multiple plastic film bag having a filling port for filling a liquid, wherein the liquid is contained in the bag. An inner bag for a liner, which is filled and housed in an outer container, wherein the surface of the outermost film of the inner bag is roughened; and (2) the inner bag for the liner Folding the inner bag so that the filling port comes out to the front side, storing the inner bag in the outer container such that the filling port faces upward, and then filling the bag with liquid from the filling port. And a liquid filling method.
In the present invention, the surface is roughened,
It means that the center line average roughness of the surface is 0.2 μmRa or more.

Here, it is preferable that the surface of the outermost film of the inner bag is formed of linear polyethylene having a density of 0.905 to 0.918 g / cm ^3. It is more preferable that the surface of the outer film is roughened by embossing. More preferably, the inner bag is a liner of a large-sized bag-in-box filled with a liquid of 100 liters or more. And it is more effective when the heated liquid food is filled in the liner inner bag.

That is, according to the present invention, when the inner bag is folded by roughening the surface of the outermost film of the inner bag for the liner, the contact area between the outer surfaces of the overlapping inner bags is reduced, and the overlapping portion is reduced. As the slipperiness in is improved,
Blocking at the contact surface is prevented.

Here, if the surface of the outermost film of the inner bag is formed of linear polyethylene having a density of 0.905 to 0.918 g / cm ³ , pinhole resistance and
It is preferable because an inner bag excellent in heat seal stability and production speed can be obtained. The density is 0.905 g / cm
^When it is less than ³ , the liquid pressure of the content liquid may not be able to withstand, and pinholes are easily generated. On the other hand, when the density is 0.
If it exceeds 918 g / cm ³ , flexibility at low temperatures may be insufficient, and pinholes are likely to occur.

Further, when the surface of the outermost film of the inner bag is roughened by embossing, the film surface of such an inner bag can be roughened to an arbitrary degree, and the quality is stable. This is more preferable because the inner bag can be easily manufactured.

If the inner bag is an inner bag of a large bag inbox filled with liquid of 100 liters or more, it is impossible to put the filled inner bag in the outer container. In this method, the inner bag is placed in an outer container and then filled, but since such an inner bag has a large contact area between the outer films, blocking easily occurs, and the work of repairing the generated blocking is performed. It is particularly effective because it is difficult.

Therefore, the inner bag for liner is folded so that the filling port is exposed on the front side, and the inner bag is stored in the outer container such that the filling port is on the upper side. According to the filling method of the present invention for filling in a bag,
The outer surfaces of the inner bag are stuck together, so-called blocking does not occur.
And it can be filled reliably. Therefore, since the inner bag is already stored in the outer container before the content liquid is filled, it is possible to easily fill a large liquid container exceeding, for example, 20 liters.

Here, the filling method of the present invention is not limited to the target contents, but when the liquid is heated, blocking easily occurs and it can be effectively prevented. For example, it is particularly useful when filling a liquid food immediately after heat sterilization and sterilization.

The use of the liner inner bag of the present invention is not particularly limited. For example, it is suitable for use as a liner for a drum.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. FIG. 1 is a plan view showing the liner inner bag 1 in a folded state to explain a configuration example of the present invention, and FIG. 2 is a partially enlarged cross-sectional view illustrating the configuration of the liner inner bag 1. FIG. 3 is a longitudinal sectional end view schematically showing a state in which the inner bag 1 for a liner is filled with liquid, and FIG. 4 is a partially enlarged cross-sectional view schematically showing an enlarged portion A in FIG. It is.

The inner bag 1 for a liner is composed of a bag body 2 whose outermost films 2a and 2a 'are roughened by embossing, as described later. The bag body 2 is folded and filled. Filling port 3 used to fill the bag body 2 with a liquid (content liquid) at a position above the bag
A discharge port 4 used for discharging the contents liquid is attached so as to be integrated with the bag body 2. 1 and 3, the outermost films 2a, 2a of the inner bag 1 are shown.
The roughened state of the surface of a ′ is omitted.

The liner inner bag 1 is used as a so-called bag-in-box inner bag by covering a container outer container 5 (see FIG. 3) made of a rigid metal, synthetic resin, wooden box or cardboard box. It is an inner bag of a large liquid container for storing and transporting the content liquid filled in the bag body 2, and its content is not particularly limited. , Preferably 100 liters or more, more preferably 500 to 2,000 liters.

As shown in FIG. 2, the bag body 2 is composed of two film layers using four films 2a, 2b, 2b 'and 2a'. The film 2a and the film 2b, and the film 2b 'and the film 2b' As shown in FIG. 1, the four sides 6, 6, and 6 a are separated from each other without being bonded to each other.
6 and 6 are heat-sealed, and the film 2a and the film 2b are filled by the hot plate sealer 9 around the filling port 3 and the discharge port 4 (not shown in FIG. 2). Is thermally welded together with the flange 3a.
The thickness and size of the film are not particularly limited, but the thickness is 60 to 400 μm and the width is 500 to 500 μm.
3,000 mm and a length of about 500 to 5,000 mm are preferable.

In the present invention, the entire inner bag does not have to be roughened as long as the contacting portion at the time of filling is roughened, but the outermost surface constituting the outermost surface of the bag body 2 is not required. The surface of the film 2a is preferably roughened by embossing, and the surface of the film 2a 'is preferably roughened by embossing. The size and shape of the concavities and convexities due to the embossing are not particularly limited. For example, when the concavities and convexities are roughened by continuous corrugated concavities and convexities as shown in FIG. It is more preferable that (h in the figure) is 0.2 to 10 μm, the diameter (r in the figure) is 0.2 to 20 μm, and the distance (L in the figure) between adjacent convex portions is about 0.2 to 50 μm. It is. In the present invention, the means for roughening the film surface is not limited to embossing, but embossing is preferable in consideration of production efficiency and the like.

The shape of the bag body 2 is not particularly limited. For example, the bag body 2 is a four-sided sealed bag, a gusset bag, or the like that is closed around four sides except that the filling port 3 and the discharge port 4 are open. , From the state of being folded into a flat square, rectangular or triangular shape, by filling the content liquid,
A container configured to be cubic or rectangular according to the shape of the outer container can be suitably used.

The material of the bag body 2 is not particularly limited as long as it is formed of a foldable and sealable plastic film as described above. For example, polyethylene, polypropylene and ethylene vinyl acetate may be used. Polymers, polyolefins such as ionomers, polyethylene terephthalate (PET), inorganic vapor-deposited PET, polyvinyl alcohol, polyamide and the like obtained by laminating the above-mentioned polyolefin as a seal layer can be suitably used. A single-layer film may be used, or a multilayer film obtained by appropriately combining and laminating them may be used.

When the bag body 2 is a double film as described above, the material of each film may be the same or different, but the outermost film on the outer surface side of the bag is used. 2a and 2a 'have a density of 0.905 to 0.91.
8 g / cm ³ linear polyethylene film,
More preferred. Incidentally, the outermost film 2a, as 2a ', the case of using a laminated film, it is preferable that the outermost layer of the film is to be formed by linear polyethylene having a density of 0.905~0.918g / cm ^3.

The filling port 3 and the discharging port 4 provided in the bag body 2 are used when filling and discharging a liquid as a content liquid, and a cap (not shown) screwed to these is used. When the contents liquid is transported and stored, the contents liquid can be sealed with the cap so as not to leak. In the case of the inner bag 1,
Although the filling port 3 and the discharge port 4 are provided as openings, it is a matter of course that one opening, that is, only the filling port may be provided.

The method of manufacturing the inner bag 1 is not particularly limited, and it can be manufactured in the same manner as a normal bag-in-box inner bag or a drum liner. For example, four plastic films are used. Of these, the two films 2a, 2a 'constituting the outermost surface of the bag are embossed in advance to roughen the surface, and the four films 2a, 2b, 2b', 4a, 6, 6, 6, 6 of 2a 'and the peripheral portion 7 of the filling port 3 and the discharging port 4,
8 can be manufactured by a method such as heat-sealing to form a four-side sealed bag having a double film structure.

Next, a configuration example of the liquid filling method of the present invention for filling the inner bag 1 with a liquid as a content liquid will be described. In the liquid filling method of the present invention, the type of liquid to be filled is not particularly limited.However, in view of the object of the present invention, the liquid is filled at a high temperature immediately after being sterilized by heating and sterilized. Liquids are effective, and examples of such liquids include foods such as sauce, mineral water, sake, caramel, and shortening. And the temperature at the time of filling is 60 to 90 ° C,
Particularly, 65 to 85 ° C. is effective. The filling method of the present invention may be used to lower the viscosity by heating an industrial chemical or the like, and to improve the filling efficiency.

When filling the inner bag 1 with a liquid, the bag main body 2 is folded into a flat bag shape as shown in FIG. 1, and this is filled into the outer container 5 of the bag-in-box as shown in FIG. It is stored so that the opening 3 is on the upper side, and set so that the filling opening 3 is located at the tip of a filling hose 10 connected to a filling tank (not shown).

Then, the filling port 3 and the tip of the filling hose 10 are connected in a liquid-tight manner, and the liquid in the filling tank is supplied through the filling hose 10 through the filling hose 10 as shown by an arrow X in the figure. Pour into bag.

Here, as the inner bag 1 is filled with the liquid, a force is applied to the folded inner bag 1 in a direction of inflating the inner bag as indicated by an arrow Y in the drawing by water pressure. . At this time, in the portion where the outermost films 2a and 2a 'constituting the outermost surface of the inner bag 1 overlap, for example, the outermost film 2a shown in FIG. (Indicated by arrows Z ₁ and Z _{2 in the} figure), but in the case of the present invention, since the surfaces of the outermost films 2a and 2a 'are roughened, the contact area in the overlapping portion is small, and Because it is slippery, there is no blocking or sticking.

Therefore, according to the inner bag 1, even if the bag surfaces are overlapped with each other, the surfaces can be slid smoothly. It is possible to easily and surely fill a required amount of the content liquid, and since the inner bag filled with the content liquid is already stored in the outer container, even if the inner volume is large, the outer container It is easy to store in.

On the other hand, in the case of the conventional inner bag in which the surface of the inner bag is not roughened, a force in the opposite direction is applied to the portion where the outermost film 2c overlaps as shown in FIG. When the arrows Z ₁ and Z ₂ ) act, these contact areas are large, making it difficult to slip, causing sticking of the film and blocking. Therefore, in order to reliably fill the required amount of the content liquid, it is necessary to continuously monitor whether such a situation occurs during the filling operation and to correct the position of the inner bag when blocking or the like occurs. Work must be performed, such as peeling off the stuck part.

The inner bag for a liner of the present invention is not limited to the above-described structure, and may be variously modified without departing from the gist of the present invention.

Next, the present invention will be described more specifically with reference to examples and comparative examples.

First, with respect to the plastic film constituting the inner bag for the liner, for a film having a roughened surface and a film having no surface roughened, the change due to the temperature change of the side slip in a state where these surfaces are overlapped is described below. Investigated by example.

[Experimental Example] Using linear low-density polyethylene with a single-site catalyst having a density of 0.905 g / cm ³ , the center line average roughness was 2.3 μm Ra (the height (h) of one convex portion was 1 to 5 μm, a diameter (r) of 0.5 μm, and a gap (L) between adjacent protrusions of 0.7 μm), the surface of which is roughened by embossing to form a 100 μm thick film. By using the same linear polyethylene, a film having a thickness of 100 μm whose surface was not roughened was prepared.
By measuring the slip (tan θ) at 80 ° C. and 80 ° C., the change in slipperiness due to the temperature change of both films was evaluated. Table 1 shows the results.

[0038]

[Table 1] *: "Not slippery" means that tan θ> 1.73, that is, θ
> 60 °.

According to the results shown in Table 1, a polyethylene film having an unroughened surface shows little change in slipperiness due to temperature change up to 23 to 60 ° C., but has a lower slipperiness when heated to 70 ° C. Lost.

On the other hand, in the case of the polyethylene film having a roughened surface, the slipperiness deteriorated as the temperature increased, but the slipperiness was not lost even when the film was heated to 80 ° C.

According to the above results, it was confirmed that the surface smoothness of the film surface was improved by roughening the surface of the linear low-density polyethylene film.

EXAMPLES AND COMPARATIVE EXAMPLES Next, as an example, a linear low-density polyethylene produced by a single-site catalyst having a density of 0.905 was prepared with a thickness of 100 μm and a width of 2,100.
mm, a film with a length of 2,200 mm, and using two films, two of which were roughened by embossing and two of which were not roughened in the same manner as in the above experimental example, a total of four films Then, a four-sided sealing bag provided with a filling port and a discharging port so that the roughened film becomes the outermost film was prepared. On the other hand, as a comparative example, a four-sided seal bag provided with a filling port and a discharge port was prepared using a film whose surface was not roughened in all four sheets.

The four-side seal bag of the above embodiment and the four-side seal bag of the comparative example were folded in the same manner, and the inner dimensions were 1.0 and 0, respectively.
After mounting in a 60 mm cube synthetic resin container, each bag was filled with 1000 liters of hot water at 70 ° C., and the state of each bag during the filling operation was observed.

As a result, in the case of the four-sided sealed bag of the comparative example where the surface is not roughened, blocking occurs immediately after filling, the position of the inner bag must be corrected at the time of filling 50 liters, and further filling is carried out. However, the inner bag did not spread at 500 liters, and it was difficult to fill it further.

On the other hand, in the case of the four-sided seal bag having a roughened surface according to the embodiment, the inner bag naturally expands due to water pressure without correcting the position of the inner bag because the bag has slipperiness even at high temperatures. The specified amount of liquid could be filled without any special operation.

According to the above results, the surface of a linear low-density polyethylene film having a density of 0.905 g / cm ³ and a height of 1 to 5 μm and a diameter of 0.5 μm having excellent pinhole resistance was obtained.
m, by roughening the surface into irregularities with a gap of 0.7 μm,
It is recognized that the slipperiness of the film surface is improved, and a prescribed amount of liquid can be easily and reliably filled even when hot water at 70 ° C. is filled.

[0047]

According to the present invention, the required amount of liquid can be easily and reliably filled in the inner bag for the liner. The present invention is particularly effective when it is made of an ultra-low-density linear low-density polyethylene film having excellent hole performance or an inner bag for a large liquid container.

[Brief description of the drawings]

FIG. 1 is a plan view of a liner inner bag in a folded state, illustrating a configuration example of a liner inner bag of the present invention.

FIG. 2 is a partially enlarged cross-sectional view illustrating a film configuration of the liner inner bag during bag making.

FIG. 3 is a vertical cross-sectional end view of the liner inner bag at the time of filling, illustrating one configuration example of the liquid filling method of the present invention.

FIG. 4 is an enlarged sectional view of a portion A in FIG. 3;

FIG. 5 is a partially enlarged cross-sectional view showing a state where a conventional liner inner bag is being filled with liquid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner bag for liner 2a, 2a 'Outermost film 3 Filling port 5 Outer container

Claims (6)

[Claims] 1. A single or multiple plastic film bag having a filling port for filling a liquid, wherein the bag is filled with a liquid and the liner inner bag is housed in an outer container. An inner bag for a liner, wherein the outermost film surface of the inner bag is roughened. 2. The liner inner bag according to claim 1, wherein the outermost film surface of the inner bag is formed of linear polyethylene having a density of 0.905 to 0.918 g / cm ³ . 3. The liner inner bag according to claim 1, wherein the surface of the outermost film of the inner bag is roughened by embossing. 4. A large-sized bag-in-box liner filled with 100 liters or more of liquid.
Or an inner bag for a liner according to 3. 5. The liner inner bag according to any one of claims 1 to 4, wherein the inner bag is folded so that the filling port is exposed to the front side.
A liquid filling method, comprising: storing the inner bag in the outer container such that the filling port faces upward, and then filling the bag with liquid from the filling port. 6. The liquid filling method according to claim 5, wherein the heated liquid food is filled in the liner inner bag.