Inner bag for cylindrical container and composite container using the same

Abstract

An inner pouch (1) for a cylindrical container, the purpose of which is to make it possible to fill the inner pouch (1) for the cylindrical container, which is easily accommodated in the cylindrical container, to a volume similar to that of the cylindrical container without requiring the work of pulling up the inner pouch (1) for the cylindrical container, which has been filled with a filling substance, to eliminate folds at a base edge of the inner pouch (1) for the cylindrical container and align the base edge (8) of the inner pouch (1) for the cylindrical container with a position near the top center of a base surface of the cylindrical container, and a composite container using the inner pouch (1), characterized in that: the inner pouch (1) for the cylindrical container, formed by closing at least left and right end sections (3) and a lower section (4) of an overlapped or folded-over film (2), comprises a filling substance storage section (5) and a support mechanism section (6) below the filling substance storage section; and the support mechanism section (6) comprises a support mechanism (7) that regulates the position of the base edge (8) of the inner pouch within the cylindrical container.

Description

Technical Field

[0001] The present invention relates to an inner bag used for a cylindrical container made of metal or plastic with a relatively large capacity such as a tank or a drum can, and a composite container using the same.

Background Art

[0002] Conventionally, when filling a cylindrical container with a relatively large capacity such as a tank or a drum can with a liquid such as a chemical, an inner bag formed from a film may be used for the purpose of preventing the inside of the cylindrical container from being soiled by the filling material. By inserting the inner bag into the cylindrical container in advance and filling the inner bag in the cylindrical container instead of directly filling the filling material into the cylindrical container, the cylindrical container can be repeatedly used simply by replacing the inner bag without cleaning the cylindrical container after discharging the contents. Therefore, a cylindrical container containing an inner bag is widely used.

[0003] As the inner bag, for example, as shown in FIG. 9, a flat inner bag 21 in which the peripheries (left and right end portions 23 and bottom portion 24) of two films 22 are closed so as to form a bag is used. The width of this inner bag is approximately half of the inner peripheral length of the cylindrical container, and the volume of the inner bag is substantially the same as the volume of the cylindrical container. The film thickness is about 0.01 to 0.5 mm. However, since the force applied to the inner bag by the weight of the filling material is borne by the container, the inner bag usually does not break due to the weight of the filling material.

[0004] When filling a filler into an inner bag housed in a cylindrical container, first, the inner bag is inserted into the cylindrical container. As described above, the width of the inner bag is approximately half of the inner circumference of the cylindrical container. That is, since it is a flat flat bag with a width longer than the inner diameter (or diameter) of the cylindrical container, the center of the bottom side of the inner bag is bent at the bottom of the cylindrical container and is housed in a U-shaped or S-shaped state (in plan view). When the inner bag is filled with the filler in this state, when the side surface (or the front and back) of the inner bag is pushed and expanded by the weight of the filler and bulges, the bottom side of the inner bag maintains the bent state, and the lower part of the inner bag cannot spread sufficiently inside the cylindrical container, and the inner bag tilts and hangs down inside the cylindrical container, and it was not possible to fill the inner bag completely with the filler. When trying to fill the inner bag housed in the cylindrical container to about the same volume as the volume of the cylindrical container (90 to 100% of the volume in the cylindrical container), it is necessary to lift the inner bag filled with the filler and eliminate the bend near the center of the bottom side of the inner bag and align the bottom side of the inner bag with the center of the bottom surface of the cylindrical container. However, when lifting, there is a risk that the film will stretch due to the weight of the filler and lead to bag breakage.

[0005] In response to such problems, Patent Document 1 describes that the lower part of the inner body bag for the container is trapezoidal and narrows downward, the length of the short side of the trapezoid is 0.8 to 1.2 times the inner diameter of the container, and the height of the trapezoid is 0.4 to 0.6 times the inner diameter of the container. And Patent Document 1 describes that with such a configuration, the lower part of the inner body bag does not bend when the inner body bag is inserted into the container, and it is located almost at the center of the bottom of the container.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, even with a trapezoidal inner bag where the lower part of the inner bag narrows downward, since the upper to middle parts of the inner bag are accommodated in a bent state, simply inserting it would cause the bottom of the inner bag to bend following the bend from the upper to middle parts of the inner bag, and the lower part of the inner bag could not fully expand inside the cylindrical container. Also, because the bottom of the inner bag was bent, the bottom of the inner bag was located at a point slightly offset from the center of the bottom of the cylindrical container. When filling the filler, the inner bag tilted and hung upside down inside the cylindrical container, and the inner bag accommodated in the cylindrical container could not be filled to approximately the same volume as the cylindrical container.

[0008] The present invention has been made in view of such problems, and there is no need for operations such as lifting the inner bag containing the filler to eliminate the bend at the bottom of the inner bag and aligning the bottom of the inner bag near the center of the bottom surface of the cylindrical container. An object of the present invention is to provide an inner bag for a cylindrical container that can easily fill the inner bag accommodated in the cylindrical container to approximately the same volume as the cylindrical container, and a composite container using the same.

Means for Solving the Problems

[0009] According to the present invention, (1) An inner bag for a cylindrical container in which at least the left and right ends and the lower part of the overlapped or folded film are closed, The inner bag has a filler storage part and a support mechanism part below the filler storage part, The support mechanism part has a support mechanism for regulating the position of the bottom of the inner bag in the cylindrical container, and an inner bag for a cylindrical container is provided. (2) The inner bag for a cylindrical container according to (1), wherein the support mechanism part has a support mechanism composed of a rod-shaped support member in the storage space. (3) The inner bag for a cylindrical container according to (1), wherein the support mechanism part has a support mechanism composed of a rod-shaped support space in which the sealed space expands due to internal pressure. (4) The above-described support mechanism portion has a support mechanism composed of a rod-shaped support member on the outer or inner side near the bottom edge of the bag. The inner bag for a cylindrical container described in (1) is provided. (5) The support mechanism is such that its length substantially coincides with the diameter of a circle formed by the inner peripheral length of the inner bag. The inner bag for a cylindrical container described in any one of (1) to (4) is provided. (6) The support mechanism is arranged parallel to the bottom edge of the inner bag. The inner bag for a cylindrical container described in any one of (1) to (5) is provided. (7) The support mechanism is arranged at the center in the width direction of the inner bag. The inner bag for a cylindrical container described in any one of (1) to (6) is provided. (8) The inner bag has an injection / extraction port at the upper part. The inner bag for a cylindrical container described in any one of (1) to (7) is provided. (9) A composite container comprising a cylindrical container and the inner bag for a cylindrical container described in any one of (1) to (8), wherein the width of the inner bag is approximately half of the inner peripheral length of the cylindrical container, and the support mechanism regulates the position of the bottom edge of the inner bag in the cylindrical container, and the bottom edge of the inner bag is positioned near the center of the bottom surface of the cylindrical container. A composite container is provided.

Advantages of the Invention

[0010] The inner bag for a cylindrical container of the present invention has a support mechanism portion having a function of regulating the position of the bottom edge of the inner bag in the cylindrical container below the filling material storage portion. Therefore, when the inner bag is accommodated in the cylindrical container, the bottom edge of the inner bag is positioned near the center of the bottom surface of the cylindrical container. When the filling material is filled, the inner bag does not bend inside the cylindrical container, and it is possible to easily fill the inner bag accommodated in the cylindrical container to approximately the same volume as the cylindrical container. Also, since there is no need for operations such as lifting the inner bag containing the filling material, there is no risk of the film stretching and bursting due to the weight of the filling material during lifting.

Brief Description of the Drawings

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, the present invention will be described in detail. Note that the present invention is not limited to the following embodiments, and various forms can be adopted within the scope where the effects of the present invention can be achieved.

[0013] [Inner Bag for Cylindrical Containers] FIG. 1 is a front view of the inner bag for cylindrical containers showing Embodiment 1 of the present invention. As shown in FIG. 1, in the inner bag 1 for cylindrical containers of the present invention, at least the left and right end portions 3 and the lower portion 4 of the overlapped or folded film 2 are closed so as to form a bag, and it has a filling storage portion 5 and a support mechanism portion 6 located below it.

[0014] The inner bag for a cylindrical container is a flat flat bag in which the left and right ends and the lower part of the overlapped or folded film are closed to form a bag. The method of closing the left and right ends and the lower part to form a bag is not particularly limited, and examples include a method of sealing by heat fusion, a method of sealing using an adhesive, etc. Specifically, for example, a method of cutting a film extruded into a cylindrical shape using an inflation extrusion molding method or the like to a predetermined length and sealing the lower part, a method of sealing the left and right ends and the lower part of two overlapped films, a method of sealing one of the left and right ends and the lower part of a semi-folded film, etc. can be mentioned, but it is not limited thereto. Note that a flat bag is one that appears flat in a state where no filling material is filled, and it may have processes such as a gusset or a fold, but it is preferably without processes such as a gusset or a fold.

[0015] The resin composition of the film is not particularly limited, and polyethylene-based resins such as linear low-density polyethylene, low-density polyethylene, and high-density polyethylene, polypropylene-based resins, ethylene-vinyl alcohol copolymer resins, polyester-based resins, nylon-based resins, etc., resins that have been conventionally used as inner bags for cylindrical containers with a relatively large capacity such as drums can be used. Also, the thickness of the film is not particularly limited and is about 0.01 to 0.5 mm.

[0016] The inner bag for a cylindrical container has a filling material storage part 5 for storing a filling material inside and a support mechanism part 6 for regulating the position of the bottom edge 8 of the inner bag 1 in the cylindrical container below it, and the filling material storage part 5 and the support mechanism part 6 are partitioned by sealing the lower part 4 of the inner bag. The filling material storage part is a space for storing filling materials such as liquids and powders such as ink, pharmaceuticals, and vaccines, and it may be designed to be approximately the same as the volume of the cylindrical container.

[0017] The support mechanism portion 6 has a support mechanism 7 that regulates the position of the bottom edge 8 of the inner bag 1 within the cylindrical container. Regulating the position of the bottom edge 8 of the inner bag 1 within the cylindrical container means positioning the bottom edge 8 of the inner bag 1 accommodated in the cylindrical container so as to pass through the center of the bottom surface of the cylindrical container. For example, by providing a support mechanism 7 having a length that substantially matches the diameter of a circle (or the major axis of the bottom surface of the cylindrical container) with a circumference substantially the same as the inner circumference of the inner bag 1 near the bottom edge 8 of the inner bag 1, the bottom edge 8 of the inner bag 1 within the cylindrical container can be regulated near the center of the bottom surface of the cylindrical container. With such a configuration, when filling the inner bag accommodated in the cylindrical container with a filling material, the bottom edge near the center of the inner bag does not bend, so that the side surface (or the front and back) of the inner bag is evenly pushed out and inflated by the weight of the filling material, and the inner bag can be filled with the filling material to the brim. Since it is difficult to precisely position the bottom edge of the inner bag so as to pass through the center of the bottom surface of the cylindrical container, it is sufficient if the bottom edge of the inner bag passes through the central portion within 10% of the distance from the center of the bottom surface of the cylindrical container, preferably through the central portion within 5% of the distance from the center of the bottom surface of the cylindrical container, and more preferably through the central portion within 3% of the distance from the center of the bottom surface of the cylindrical container.

[0018] The support mechanism portion may have any configuration as long as it has a support mechanism that regulates the position of the bottom edge of the inner bag within the cylindrical container as described above. For example, as shown in FIG. 1, a seal of the lower part 4 is provided below the inner bag, a storage space is provided between the lower part 4 and the bottom edge 8 (or the bottom edge seal), and a support mechanism 7 composed of a rod-shaped support member may be arranged in the storage space. The support mechanism is not particularly limited as long as it has a rigidity (or strength) such that the bottom edge of the inner bag does not bend due to the weight of the filling material or the like. Examples include paper, wood, synthetic resin, metal, glass, etc. Note that the term "rod-shaped" refers to an elongated columnar shape, but the shape is not strictly questioned as long as it has a function of regulating the position of the bottom edge of the inner bag inside the cylindrical container. The support mechanism portion may have a configuration in which the left and right ends of the storage space between the lower part 4 and the bottom edge 8 are open as shown in FIG. 2 in order to arrange the support mechanism after forming the inner bag.

[0019] As shown in FIG. 3, the support mechanism portion may be configured to provide a seal for the lower part 4 below the inner bag 1 and arrange a support mechanism 7 composed of a rod-shaped support space filled with gas, liquid, powder, etc. in a sealed space partitioned by a seal or the like between the lower part 4 and the bottom edge 8 (or the bottom edge seal) to apply internal pressure and expand it. The sealed space may be configured to be integrated with the seals of the lower part 4 and the bottom edge 8.

[0020] The support mechanism portion may be configured to arrange a support mechanism composed of a rod-shaped support member outside or inside near the bottom edge of the inner bag. For example, as shown in FIGS. 4 and 5, a seal for the lower part 4 (which corresponds to the bottom edge of the bag in this case) is provided below the inner bag 1, and a support mechanism 7 (which corresponds to the support mechanism portion in this case) composed of a rod-shaped support member is fixed by a jig such as heat fusion, an adhesive, or a clip outside or inside near the bottom edge of the inner bag 1. The support mechanism may be fixed so that the bottom edge of the inner bag housed in the cylindrical container can be positioned near the center of the bottom surface of the cylindrical container. In this case, it may be arranged directly above or below the bottom edge. Note that the support mechanism may be formed integrally with the inner bag. For example, a film below the seal of the lower part 4 of the inner bag wound into a roll and fixed in a rod shape may be used as the support mechanism.

[0021] The support mechanism portion may be rectangular with a length shorter than the width of the inner bag as shown in FIG. 6, or trapezoidal narrowing downward as shown in FIG. 7 below the inner bag. In this case, it is preferable that the length of the rectangle or the length of the short side of the trapezoid is substantially the same as the diameter of the circle formed by the inner peripheral length of the inner bag.

[0022] In the inner bag, the support mechanism is preferably arranged parallel to the bottom edge of the inner bag. By arranging it parallel to the bottom edge of the inner bag, when the filling material is filled, the vicinity of the center of the bottom edge of the inner bag does not bend inside the cylindrical container, and the inner bag can be filled with the filling material to the brim.

[0023] The support mechanism is preferably arranged at the center in the width direction of the inner bag. Since the support mechanism has a length substantially equal to the diameter of the circle formed by the inner peripheral length of the inner bag (or the major axis of the bottom surface of the cylindrical container), it is about 30% shorter than the width of the inner bag. Therefore, it is preferably arranged 5% or more inward from the left and right ends of the inner bag, more preferably 10% or more inward, and even more preferably 15% or more inward. The method of fixing the position of the support mechanism in the width direction of the inner bag is not particularly limited. For example, the positions near both ends of the support mechanism in the storage space may be sealed to fix the position of the support mechanism.

[0024] The length of the support mechanism is preferably 85% or more and 115% or less of the diameter of the circle formed by the inner peripheral length of the inner bag. More preferably, the length of the support mechanism is 90% or more and 105% or less of the diameter of the circle formed by the inner peripheral length of the inner bag, even more preferably 90% or more and 100% or less, and particularly preferably 95% or more and less than 100%. If the length of the support mechanism is within the above range, when the inner bag is accommodated inside the cylindrical container, the bottom edge of the inner bag can be positioned near the center of the bottom surface of the cylindrical container.

[0025] The upper part of the inner bag may be closed leaving a path for filling the filling material. Also, a configuration may be adopted in which an injection / extraction port 9 is provided at the upper part of the inner bag. A plurality of injection / extraction ports may be provided at the upper part of the inner bag.

[0026] [Composite container] FIG. 8 is a cross-sectional view of a composite container using an inner bag for a cylindrical container showing an embodiment of the present invention. As shown in FIG. 8, the composite container 11 of the present invention includes a cylindrical container 13 and the above-described inner bag 12 for a cylindrical container. The bottom edge of the inner bag is positioned near the center of the bottom surface of the cylindrical container by the support mechanism 14 of the inner bag. Since the bottom edge of the inner bag is positioned near the center of the bottom surface of the cylindrical container, when filling the filling material into the inner bag accommodated in the cylindrical container, the bottom edge near the center of the inner bag does not bend, and the side surface of the inner bag is evenly pushed and expanded by the weight of the filling material and bulges, and it is possible to easily fill the inner bag accommodated in the cylindrical container to approximately the same volume as the cylindrical container.

[0027] The cylindrical container is a relatively large open drum made of metal or plastic with a capacity of about 10 to 5000 L. It may be configured to cover and seal the upper opening with a top plate (not shown). When a top plate is provided at the upper opening, a hole for taking out the port of the inner bag to the outside may be provided in the top plate.

[0028] The width of the inner bag for the cylindrical container is approximately half of the inner circumference of the cylindrical container. Preferably, the width of the inner bag for the cylindrical container is 45% or more and 60% or less of the inner circumference of the cylindrical container, more preferably 47.5% or more and 55% or less, and even more preferably 47.5% or more and less than 52.5%. With such a configuration, when the inner bag is filled inside the cylindrical container, the inner bag follows the cylindrical container, so the container can bear the force applied to the inner bag due to the weight of the filling material, and it is possible to suppress the inner bag from being damaged due to the weight of the filling material.

[0029] Preferably, the length of the support mechanism is 85% or more and 115% or less of the major axis of the bottom surface of the cylindrical container. More preferably, the length of the support mechanism is 90% or more and 105% or less of the major axis of the bottom surface of the cylindrical container, even more preferably 90% or more and 100% or less, and particularly preferably 95% or more and less than 100%. If the length of the support mechanism is within the above range, when the inner bag is accommodated inside the cylindrical container, the bottom edge of the inner bag can be positioned near the center of the bottom surface of the cylindrical container.

[0030] [Example 1] Using a polyethylene film with a thickness of 0.15 mm, an inner bag A for a cylindrical container with a capacity of 200 L shown in FIG. 1 was produced. The width of this inner bag is 860 mm, the height of the filling material storage part is 1450 mm, the height of the support mechanism part (storage space) is 50 mm, and a rod-shaped support member made of polyethylene (φ10 mm, length 560 mm) was arranged at the center in the width direction of the inner bag in the storage space (150 mm inward from each of the left and right ends).

[0031] When the inner bag A was placed in a cylindrical container (φ567 mm) with a capacity of 200 L, the bottom of the inner bag A was positioned at the center of the bottom surface of the cylindrical container. Next, when the inner bag A was filled with a filler made of liquid from the upper opening, the side surface of the inner bag was evenly pushed and expanded by the weight of the filler without the bottom near the center of the inner bag bending, and the inner bag easily accommodated in the cylindrical container could be filled to approximately the same volume as the cylindrical container.

[0032] [Reference Example 1] An inner bag B for a cylindrical container was produced in the same manner except that the length of the support mechanism was changed to 500 mm. When this was placed in a cylindrical container with a capacity of 200 L, the bottom of the inner bag B was positioned at a place slightly deviated from the center of the bottom surface of the cylindrical container. Next, when the inner bag B was filled with a filler made of liquid from the upper opening, the inner bag tilted and hung down inside the cylindrical container, and it was not possible to fill the inner bag completely with the filler.

Explanation of Symbols

[0033] 1: Inner bag for cylindrical container 2: Film 3: Left and right ends 4: Lower part 5: Filler storage part 6: Support mechanism part 7: Support mechanism 8: Bottom 9: Injection / extraction port 11: Composite container 12: Inner bag for cylindrical container 13: Cylindrical container 14: Support mechanism 21: Inner bag 22: Film 23: Left and right ends 24: Bottom part

Claims

Claim 1: An inner bag for a cylindrical container, wherein the inner bag is a flat flat bag in which at least the left and right ends and the lower part of the overlapped or folded film are closed, the inner bag has a filling storage part and a support mechanism part under the filling storage part, and the support mechanism part has a rod-shaped support mechanism for regulating the position of the bottom of the inner bag in the cylindrical container. The inner bag for a cylindrical container is characterized by this.

2. The inner bag for a cylindrical container according to claim 1, wherein the support mechanism part has a support mechanism composed of a rod-shaped support member in the storage space.

3. The inner bag for a cylindrical container according to claim 1, wherein the support mechanism part has a support mechanism composed of a rod-shaped support space in which the sealed space expands due to internal pressure.

4. The inner bag for a cylindrical container according to claim 1, wherein the support mechanism part has a support mechanism composed of a rod-shaped support member on the outside or inside near the bottom of the bag.

5. The inner bag for a cylindrical container according to any one of claims 1 to 4, wherein the length of the support mechanism substantially coincides with the diameter of a circle formed by the inner peripheral length of the inner bag.

6. The inner bag for a cylindrical container according to any one of claims 1 to 5, wherein the support mechanism is arranged parallel to the bottom of the inner bag.

7. The inner bag for a cylindrical container according to any one of claims 1 to 6, wherein the support mechanism is arranged at the center in the width direction of the inner bag.

8. The inner bag for a cylindrical container according to any one of claims 1 to 7, wherein the inner bag has an injection / extraction port at the upper part.

9. A composite container comprising a cylindrical container and an inner bag for a cylindrical container according to any one of claims 1 to 8, wherein the width of the inner bag is approximately half of the inner peripheral length of the cylindrical container, the support mechanism regulates the position of the bottom of the inner bag in the cylindrical container, and the bottom of the inner bag is positioned near the center of the bottom surface of the cylindrical container. The composite container is characterized by this.

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