JP7492132B2 - Film roll, filling method - Google Patents

Description

The present invention relates to a film roll and a method for filling a packaging bag manufactured using this film roll with contents.

Patent document 1 discloses a technology for filling contents into packaging bags made from a long cylindrical film unwound from a film roll.

JP 2016-117505 A

The packaging bag filled with the contents is transported in that state, but there is a risk that the packaging bag will be damaged during transportation and the contents will leak out.

The present invention was made in consideration of these circumstances, and provides a technology that can prevent leakage of contents from packaging bags.

According to the present invention, there is provided a film roll in which a cylindrical long film is wound into a roll, the cylindrical long film being formed by forming a vertical seal portion in a multi-layer film to give it a cylindrical shape, and the multi-layer film has an inner film and an outer film that are overlapped on top of each other.

The cylindrical long film constituting the film roll of the present invention is composed of a multi-layer film having an inner film and an outer film. Therefore, the packaging bag manufactured using such a film roll is also composed of a multi-layer film, and even if the outer film is damaged, the inner film prevents the contents from leaking.

Various embodiments of the present invention will be described below. The embodiments described below can be combined with each other.
Preferably, in the film roll described above, the vertical seal portion is formed by bending the multi-layer film into a cylindrical shape and overlapping the inner surface of one edge of the multi-layer film with the outer surface or the inner surface of the other edge of the multi-layer film to form an overlap portion, and then welding opposing portions of the film at the overlap portion, wherein the value of {(WR-WF)/WS} is 1 or greater, where WS is the width of the overlap portion, WF is the width of the cylindrical long film, and WR is the width of the film roll.
Preferably, in the film roll described above, the tubular long film is wound around a core shaft, and when the maximum diameter of the portion of the core around which the tubular long film is wound is D1 and the minimum diameter of the portion of the core around which the overlapping portion is wound is D2, D2/D1 is smaller than 1.
Preferably, in the above-described film roll, the multi-layer film is a flattened multi-layer film obtained by flattening a tubular film.
Preferably, in the film roll described above, the tubular long film has local seal portions at equal intervals along the longitudinal direction of the tubular long film, and the inner film and the outer film are welded to each other at the local seal portions.
Preferably, the method for filling contents into a packaging bag manufactured using the above-described film roll includes a lower transverse sealing step, a cutting step, a filling step, and an upper transverse sealing step, in which in the lower transverse sealing step, a lower transverse seal portion is formed so as to cross the tubular long film, in the cutting step, the tubular long film is cut at a position adjacent to and upstream of a local seal portion provided upstream of the lower transverse seal portion to form a packaging bag having an open upper end, in the filling step, contents are filled into the packaging bag from the upper end of the packaging bag, and in the upper transverse sealing step, an upper transverse seal portion is formed so as to close the upper side of the packaging bag.

FIG. 1 is a perspective view of a film roll 1 according to one embodiment of the present invention. 2 is a cross-sectional view of the cylindrical long film 2 of the film roll 1 of FIG. 1. 2 is a view of the cylindrical long film 2 of the film roll 1 of FIG. 1 as viewed from below. 1 is a schematic cross-sectional view showing a state in which a cylindrical long film 2 is wound around a shaft core 12 to form a film roll 1. FIG. 5A, 5B and 5C show a process of filling the container with the contents, in which FIG. 5A is a plan view, FIG. 5B is a front view and FIG. 5C is a bottom view. 6 shows the filling process of the contents continued from FIG. 5, with FIG. 6A being a plan view, FIG. 6B being a front view, and FIG. 6C being a bottom view. 1 is a perspective view of a packaging bag 11 with an open upper end 11a separated from a tubular long film 2. FIG. 8 is a perspective view showing the state after an upper horizontal seal portion 14 has been formed in the packaging bag 11 of FIG. 7. FIG. 3 is a diagram corresponding to FIG. 2 and showing a configuration in which a tubular long film 2 has a folded vertical seal portion 5. FIG. 3 is a diagram corresponding to FIG. 2 and showing a configuration in which a tubular long film 2 has a vertical seal portion 5 folded in half.

The following describes the embodiments of the present invention. The various features shown in the following embodiments can be combined with each other. In addition, each feature can be an invention independently.

1. Film roll 1
As shown in Fig. 1, a film roll 1 according to one embodiment of the present invention is formed by winding a tubular long film 2 into a roll. The tubular long film 2 is a film that extends continuously along the longitudinal direction of the tubular long film 2. A large number of packaging bags 11 (see Fig. 8) are formed by processing the tubular long film 2, such as welding and cutting.

1-1. Structure of the Cylindrical Long Film 2 The cylindrical long film 2 is cylindrical, and is formed by forming a vertical seal portion 5 on a multi-layer film 4 to give it a cylindrical shape.

The multi-layer film 4 is composed of multiple films stacked on top of each other. In this embodiment, as shown in FIG. 2, the multi-layer film 4 has an inner film 7 and an outer film 8 stacked on top of each other. The inner film 7 and the outer film 8 may be in a peelable adhered state to each other by an adhesion process such as clamping them with a pair of rollers. For convenience, FIG. 2 and other figures show a gap between the inner film 7 and the outer film 8.

The multi-layer film 4 may be a separable multi-layer film in which multiple separable films are stacked, or a flattened multi-layer film in which a cylindrical film is flattened. As shown in FIG. 2, in a flattened multi-layer film, the inner film 7 and the outer film 8 are connected to each other at one edge 4a and the other edge 4b in the width direction. Each film constituting the separable multi-layer film and the cylindrical film may be either a single layer film or a laminated film. The thickness of the multi-layer film 4 is, for example, 20 to 300 μm, and preferably 70 to 140 μm.

The inner film 7 and the outer film 8 may each be a single-layer film or a laminated film. A single-layer film is preferably one that is composed of a sealant layer. A laminated film is preferably one that has a sealant layer on both sides of a base layer. An adhesive layer may be provided between the base layer and the sealant layer.

The substrate layer is made of a material that has excellent strength and high impact resistance. Examples of materials that can be used for the substrate layer include polyamide, polyolefin (e.g., polyethylene), and polyester.

The base layer may be an easy-to-tear resin layer made of an easy-to-tear resin. This allows the multi-layer film 4 to be easily opened. The resin that constitutes the easy-to-tear resin layer may be, for example, a mixed resin containing a cyclic polyolefin resin.

Cyclic polyolefin resin is generally a general term for resins polymerized using cyclic olefins as polymerization units, and is described, for example, in JP-A-1-240517, JP-A-3-14882, JP-A-3-122137, etc. In the present invention, it includes not only ring-opening metathesis polymers (also called cycloolefin polymers (COP)) in which cyclic olefins are polymerized by a metathesis ring-opening polymerization reaction, but also so-called cyclic olefin copolymers (also called cycloolefin copolymers (COC)), which are copolymers of cyclic olefins and α-olefins (chain olefins), etc., graft polymers modified with unsaturated carboxylic acids or their derivatives, and hydrogenated products thereof.

In the above mixed resin, the resin that can be used in combination with the cyclic polyolefin resin is the above-mentioned polyethylene or polyolefin such as polypropylene. Among these, polyethylene is preferred, low-density polyethylene (LDPE) is more preferred, and linear low-density polyethylene (LLDPE) is particularly preferred.

The content of the cyclic polyolefin resin in the mixed resin constituting the easy-tear resin layer is preferably 3 to 99% by mass relative to the entire mixed resin (referring to the total of the cyclic polyolefin resin and the resin used in combination with the cyclic polyolefin resin). By setting the content of the cyclic polyolefin resin within this range, the easy-tear property is well achieved. The content of the cyclic polyolefin resin is more preferably 60 to 90% by mass relative to the entire mixed resin, and particularly preferably 60 to 80% by mass.

The adhesive layer is a layer for bonding the base layer and the sealant layer together, and may be made of, for example, polyethylene.

The sealant layer is preferably made of a resin with excellent heat sealability. Examples of such resins include polyolefin resins such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and ethylene-propylene block copolymer.

The sealant layer may be made of an easy peel resin. The easy peel resin preferably has cohesive failure properties. The easy peel resin is, for example, made of two or more types of heat-sealable resins, and is capable of forming a weak seal with a peel strength of approximately less than 10 N/15 mm width according to JIS K6854. In one example, the easy peel resin is made of a mixed resin of a polyethylene (PE) resin and a polypropylene (PP) or polybutene (PB) resin. In addition, when the outermost layer of the tubular film is a sealant layer made of an easy peel resin (hereinafter, "easy peel layer"), both sides of the flattened multi-layer film become easy peel layers, so that both the horizontal seal portion that welds the inner surfaces of the flattened multi-layer film together and the vertical seal portion 5 that welds the inner surface and the outer surface of the flattened multi-layer film are easily openable.

The laminated film may be either a laminate film or a coextruded film, but a coextruded film is preferred because it can be produced more cheaply than a laminate film and is more flexible, making it less likely to form pinholes. It is more preferred that the coextruded film is a coextruded inflation film. It is particularly preferred that the tubular film is a coextruded inflation film. The laminate may be an extrusion laminate or a dry laminate.

As shown in FIG. 2, the vertical seal portion 5 can be formed by bending the multi-layer film 4 into a cylindrical shape so that the outer film 8 is exposed on the outer surface, overlapping the inner surface of one edge 4a of the multi-layer film 4 with the outer surface of the other edge 4b to form an overlap portion 5a, and then welding opposing portions of the multi-layer film 4 at the overlap portion 5a. In the vertical seal portion 5, the inner film 7 and the outer film 8 on the one edge 4a side are welded, the inner film 7 and the outer film 8 on the other edge 4b side are welded, and the inner film 7 on the one edge 4a side and the outer film 8 on the other edge 4b side are welded. In this embodiment, the vertical seal portion 5 is an envelope-type vertical seal portion.

As shown in FIG. 3, the cylindrical long film 2 has local seal portions 9 at equal intervals along the longitudinal direction of the cylindrical long film 2. In the local seal portions 9, the inner film 7 and the outer film 8 are welded to each other. As shown in FIG. 7, when filling the contents into a packaging bag 11 with an open upper end 11a manufactured from the cylindrical long film 2, if a space is formed between the inner film 7 and the outer film 8 at the upper end 11a of the packaging bag 11, it may be difficult to carry out the filling process. However, by providing the local seal portion 9 near the upper end 11a and welding the inner film 7 and the outer film 8, the formation of a space between the inner film 7 and the outer film 8 is suppressed.

The interval at which the local seal portions 9 are provided is preferably equal to the height of the packaging bag 11. This allows the filling process to be carried out with the local seal portions 9 disposed at specific positions near the upper end 11a of the packaging bag 11. The local seal portions 9 may be formed in spots or strips. The local seal portions 9 may be provided on the entire circumference of the tubular long film 2, or may be provided on a portion of the circumference. When the local seal portions 9 are provided on a portion of the circumference of the tubular long film 2, the local seal portions 9 are preferably provided at a position away from the vertical seal portions 5, and are preferably provided on the opposite side of the vertical seal portions 5 (for example, a position shifted by 1/2 of the entire circumference of the tubular long film 2). This is because a space is likely to be formed between the inner film 7 and the outer film 8 at such a position.

1-2. Winding method of the cylindrical long film 2 The cylindrical long film 2 is wound into a roll to form the film roll 1. If the cylindrical long film 2 is wound without being displaced in the width direction, the overlapping portion 5a will be overlapped, and the film roll 1 will become locally thick and bulge at the overlapping portion 5a.

To prevent the film roll 1 from becoming thick locally, it is preferable to roll the tubular long film 2 while displacing the tubular long film 2 in the width direction, as shown in FIG. 4. This distributes the positions of the overlapping portions 5a, thereby mitigating local swelling of the film roll 1.

If the width of the overlapping portion 5a is WS, the width of the cylindrical long film 2 is WF, and the width of the film roll 1 is WR, the displacement amount can be defined as {(WR-WF)/WS}. If the cylindrical long film 2 is wound without displacement, WR=WF, and the displacement amount is 0. On the other hand, the greater the displacement of the cylindrical long film 2, the greater the width WR of the film roll 1. The displacement amount is preferably 1 or more. In this case, the overlapping portion 5a is distributed over a range twice the width, so that local swelling of the film roll 1 is greatly alleviated. The displacement amount is, for example, 1 to 100, and specifically, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, and may be within a range between any two of the numerical values exemplified here.

The cylindrical long film 2 is usually wound around the shaft core 12, so WR>WF can be achieved by winding the cylindrical long film 2 around the shaft core 12 while displacing the shaft core 12 along the axial direction X of the shaft core 12.

If the maximum diameter of the portion 12a of the core 12 around which the cylindrical long film 2 is wound is D1 and the minimum diameter of the portion 12b around which the overlapping portion 5a is wound is D2, then D2/D1 is preferably smaller than 1. In other words, it is preferable that the core 12 is narrowed at the portion around which the overlapping portion 5a is wound. This reduces local swelling of the film roll 1. D2/D1 is, for example, 0.1 to 0.99, and preferably 0.5 to 0.9. Specifically, D2/D1 is, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 0.95, or 0.99, and may be within a range between any two of the numerical values exemplified here. In addition, when the cross section of the core 12 is noncircular, the "diameter" means the circle-equivalent diameter of the cross section. The vertical seal portion 5 is preferably wound around the center of the shaft core 12 in the axial direction, and the portion 12b is preferably provided in the center of the axial direction. The diameter of the shaft core 12 may be gradually reduced from the end of the shaft core 12 toward the portion 12b, or a step may be provided between the portion 12b and the adjacent portion so that the diameter of the portion 12b is reduced.

2. Method of Filling Contents Next, a method of filling the packaging bag 11 produced using the film roll 1 with contents will be described with reference to FIGS.

This method includes a lower horizontal sealing process, a cutting process, a filling process, and an upper horizontal sealing process. By repeating these processes, a large number of packaging bags 11 can be efficiently manufactured.

The cylindrical long film 2 unwound from the film roll 1 can be transported downstream by the transport device 15, and when a predetermined position of the cylindrical long film 2 reaches a position where the lower transverse sealing device 16 or the cutting device 17 is provided, the lower transverse sealing process or the cutting process is carried out. In addition, the filling process and the upper transverse sealing process are carried out on the packaging bag 11 with the upper end opened after being cut off in the cutting process, using a filling device and an upper transverse sealing device (not shown).

The conveying device 15 is a device for conveying the tubular long film 2 in the downstream direction, and in one example, includes a pair of rollers 15a, and is configured to convey the tubular long film 2 in the downstream direction by rotating in opposite directions while sandwiching the tubular long film 2 between the pair of rollers 15a. The lower horizontal sealing device 16 is a device for forming the lower horizontal seal portion 13, and in one example, includes a pair of seal bars 16a, and is configured to form the lower horizontal seal portion 13 shown in FIG. 6 by sandwiching the tubular long film 2 between the pair of seal bars 16a and heating it. The cutting device 17 is a device for cutting the tubular long film 2, and in one example, is configured to cut the tubular long film 2 by sandwiching the tubular long film 2 between a pair of blades 17a.

Each process is explained below.

5 , a lower horizontal seal portion 13 is formed across the tubular long film 2 in a lower horizontal seal device 16. In the lower horizontal seal portion 13, the opposing inner films 7 are welded to each other, and the opposing inner film 7 and outer film 8 are welded to each other. The lower horizontal seal portion 13 is preferably formed to extend perpendicular to the longitudinal direction of the tubular long film 2.

Next, the conveying device 15 conveys the tubular long film 2 downstream by one pitch (corresponding to the height of the packaging bag 11). The state after conveying is shown in FIG.

In the cutting process, in the state shown in FIG. 6, the tubular long film 2 is cut in a cutting device 17 at a position upstream of the lower horizontal seal section 13 to form a packaging bag 11 with an open upper end 11a as shown in FIG. 7. When the local seal section 9 is provided on the tubular long film 2, it is preferable to cut the tubular long film 2 at a position adjacent to the local seal section 9 provided upstream of the lower horizontal seal section 13 on the upstream side. The cutting of the tubular long film 2 is preferably performed along a direction perpendicular to the longitudinal direction of the tubular long film 2. The cutting process may be performed after forming the lower horizontal seal section 13 for the upstream packaging bag 11. In this case, the tubular long film 2 is cut at a position adjacent to the downstream side of the lower horizontal seal section 13 for the upstream packaging bag 11.

In the filling process, the contents are filled into the packaging bag 11 from the upper end 11a of the packaging bag 11 in the state shown in Fig. 7. If a space is formed between the inner film 7 and the outer film 8 at the upper end 11a of the packaging bag 11, there is a risk that the filling process may be hindered, but by providing the local seal portion 9 in the vicinity of the upper end 11a, the formation of a space between the inner film 7 and the outer film 8 is suppressed, and the filling process can be carried out smoothly.

In the upper horizontal sealing process, as shown in Fig. 8, after the contents are filled, the upper horizontal seal portion 14 is formed so as to close the upper side of the packaging bag 11. This allows the contents to be sealed inside the packaging bag 11.

3. Other Embodiments The present invention can also be implemented in the following manner.
As shown in Fig. 9, the vertical seal portion 5 may be formed by bending the multi-layer film 4 into a cylindrical shape, overlapping the inner surface of one edge 4a of the multi-layer film 4 with the inner surface of the other edge 4b of the multi-layer film 4 to form an overlap portion 5a, and then welding opposing portions of the multi-layer film 4 at the overlap portion 5a. The multi-layer film 4 is folded back at a fold-back portion 4c near the other edge 4b, and the portion between the other edge 4b and the fold-back portion 4c is overlapped with the multi-layer film 4 on the one edge 4a side to form the overlap portion 5a. In this case, the vertical seal portion 5 is a palm-to-palm type vertical seal portion. Also, the opposing outer films 8 may be welded to each other at the portion between the other edge 4b and the fold-back portion 4c.

- As shown in FIG. 10, the vertical seal portion 5 may be formed by folding the multi-layer film 4 in half and welding the opposing inner surfaces of the multi-layer film 4 near one edge 4a and the other edge 4b. The multi-layer film 4 is not folded back near the other edge 4b. This configuration has the advantage that the cylindrical long film 2 does not become thicker at the vertical seal portion 5, so no localized bulging of the film roll 1 occurs.

1: Film roll 2: Cylindrical long film 4: Multi-layer film 4a: One edge 4b: Other edge 4c: Fold-back section 5: Vertical seal section 5a: Overlap section 7: Inner film 8: Outer film 9: Local seal section 11: Packaging bag 11a: Upper end 12: Axial core 12a: Section 12b: Section 13: Lower horizontal seal section 14: Upper horizontal seal section 15: Conveyor device 15a: Roller 16: Lower horizontal seal device 16a: Sealing bar 17: Cutting device 17a: Blade X: Axial direction

Claims (5)

A film roll formed by winding a cylindrical long film into a roll,
The cylindrical long film is formed by forming a vertical seal portion on a multi-layer film to form a cylindrical shape,
The multi-layer film includes an inner film and an outer film stacked on top of each other,
The vertical seal portion is formed by bending the multi-layer film into a cylindrical shape, overlapping the inner surface of one edge side of the multi-layer film with the outer surface or inner surface of the other edge side of the multi -layer film to form an overlapping portion, and then welding opposing portions of the multi-layer film at the overlapping portion. If the width of the overlapping portion is WS, the width of the cylindrical long film is WF, and the width of the film roll is WR,
A film roll having a value of {(WR-WF)/WS} of 1 or more. 2. The film roll according to claim 1 ,
The cylindrical long film is wound around a shaft core,
If the maximum diameter of the portion of the shaft core around which the tubular long film is wound is D1 and the minimum diameter of the portion around which the overlapping portion is wound is D2,
D2/D1 is less than 1, the film roll. The film roll according to claim 1 or 2 ,
The multi-layer film is a flattened multi-layer film obtained by flattening a tubular film. The film roll according to any one of claims 1 to 3 ,
the cylindrical long film is provided with local seal portions at equal intervals along the longitudinal direction of the cylindrical long film,
The film roll, wherein the inner film and the outer film are welded to each other at the local seal portion. A method for filling a content into a packaging bag manufactured using the film roll according to claim 4 , comprising the steps of:
The method includes a lower transverse sealing step, a cutting step, a filling step, and an upper transverse sealing step,
In the lower transverse sealing step, a lower transverse seal portion is formed across the tubular long film,
In the cutting step, the tubular long film is cut at a position adjacent to and upstream of the local seal portion provided upstream of the lower transverse seal portion to form a packaging bag having an open upper end,
In the filling step, the contents are filled into the packaging bag from the upper end of the packaging bag,
In the upper horizontal sealing step, an upper horizontal seal is formed so as to close the upper side of the packaging bag.