JP2024061248A - Flexible Container Bag - Google Patents

Abstract

To provide a flexible container bag that suppresses leakage of an object to be stored from a sewn part.SOLUTION: A flexible container bag 1 includes a body part 11 and a first inner sheet 21. The body part 11 has: a trunk part 12 formed of a cylindrical sheet; and a bottom part 13 formed of a sheet that closes one opening of a cylinder of the trunk part 12. The bottom part 13 is connected to the trunk part 12 by sewing. The first inner sheet 21 is provided inside the body 11 and fixed to the trunk part 12, and has a length extending over the length from a position fixed to the trunk part 12 to a sewn part of the bottom part 13 and the trunk part 12.SELECTED DRAWING: Figure 1

Description

This disclosure relates to a flexible container bag, and in particular to a flexible container bag that prevents leakage of contents from the seams.

A flexible container bag is a bag-shaped packaging material that contains soil, sand, and other powders and granular materials for storage or transportation. Flexible container bags are generally manufactured by sewing a circular, rectangular, or other shaped bottom sheet to one opening of a cylindrical body sheet (see, for example, Patent Document 1).

JP 2020-036673 A

Flexible container bags are manufactured by sewing a bottom sheet to one opening of a cylindrical body sheet. When the bag is pushed outward by the internal pressure caused by the contents being stored inside, the contents, such as powder, can leak from the sewn area between the body sheet and the bottom sheet.

In view of the above-mentioned problems, the present disclosure relates to providing a flexible container bag that prevents leakage of contained objects from the stitching.

The flexible container bag according to the first aspect of the present disclosure comprises a main body having a body portion in which a sheet is formed into a cylindrical shape and a bottom portion formed of a sheet that closes one opening of the cylindrical shape of the body portion, the bottom portion being connected to the body portion by sewing, and a first internal sheet provided inside the main body portion, which is fixed to the body portion and has a length that exceeds the length from the position where it is fixed to the body portion to the sewn portion between the bottom portion and the body portion.

When configured in this way, when the contents are placed inside, the first internal sheet covers the sewn area between the bottom and the body, preventing the contents from directly touching the sewn area and preventing the contents from leaking from the sewn area.

In addition, as a flexible container bag according to the second aspect of the present disclosure, in the flexible container bag according to the first aspect of the present disclosure, the end of the first internal sheet that extends beyond the sewn portion between the bottom and the body may be a free end.

This simple configuration can prevent the contents from leaking from the stitching.

In addition, as a flexible container bag according to a third aspect of the present disclosure, in the flexible container bag according to the first or second aspect of the present disclosure, the first internal sheet may have a tuck formed by partially overlapping the first internal sheet in the cylindrical circumferential direction of the body portion at a portion fixed to the body portion.

This configuration can prevent the first internal sheet from peeling off from the main body.

In addition, as a flexible container bag according to a fourth aspect of the present disclosure, in the flexible container bag according to the first aspect of the present disclosure, the first inner sheet may be formed into a bag shape that is closed and covers the bottom using a liquid-proof material.

With this configuration, even if liquid is present on the inside or outside of the first internal sheet, the liquid can be prevented from moving between the inside and outside of the first internal sheet.

In addition, as a flexible container bag according to a fifth aspect of the present disclosure, in the flexible container bag according to any one of the first to fourth aspects of the present disclosure, a hanging belt connected to the torso by sewing, and a second internal sheet provided inside the main body, which is fixed to the torso on the opposite side to the bottom with respect to the sewing position of the hanging belt to the torso, and has a length that exceeds the length from the position fixed to the torso to the sewing part between the torso and the hanging belt.

This configuration helps prevent the contents from leaking from the connection points of the hanging belt.

In addition, as a flexible container bag according to a sixth aspect of the present disclosure, in the flexible container bag according to any one of the first to fifth aspects of the present disclosure, the first internal sheet may be fixed to the body portion in a state in which the end on the side fixed to the body portion is folded back and overlapped.

This configuration can prevent the first internal sheet from peeling off from the main body.

In addition, as a flexible container bag according to a seventh aspect of the present disclosure, in the flexible container bag according to any one of the first to sixth aspects of the present disclosure, an overlapping member may be provided overlapping the first internal sheet at a position where the first internal sheet is fixed to the body portion. Here, the overlapping member is typically a patch having a predetermined length in the axial direction of the cylindrical body portion, but may be formed of resin or metal. Also, it may have a shape (length) that overlaps the first internal sheet over the entire circumference of the cylindrical body portion, or may have a shape (length) that is provided intermittently in the circumferential direction.

This configuration can prevent the first internal sheet from peeling off from the main body.

In addition, as a flexible container bag according to an eighth aspect of the present disclosure, in the flexible container bag according to any one of the first to seventh aspects of the present disclosure, the first internal sheet may be fixed to the body portion by a main line extending in the circumferential direction of the cylindrical body portion, and a plurality of short lines shorter than the main line that are provided in the vicinity of the main line at predetermined intervals in the circumferential direction.

This configuration can prevent the first internal sheet from peeling off from the main body.

In addition, as a flexible container bag according to a ninth aspect of the present disclosure, in any one of the first and eighth aspects of the above-mentioned flexible container bag according to the present disclosure, the line along which the first internal sheet is fixed to the body portion may extend in a curved or broken line in the circumferential direction of the cylindrical shape of the body portion.

This configuration can prevent the first internal sheet from peeling off from the main body.

Furthermore, as a flexible container bag according to a tenth aspect of the present disclosure, in any one of the flexible container bags according to the ninth aspect of the first aspect of the present disclosure, the line along which the first internal sheet is fixed to the body portion extends in the circumferential direction of the cylindrical shape of the body portion by a predetermined width, and the predetermined width may be the length in the axial direction of the cylindrical shape of the body portion, and may be a width that allows the first internal sheet to be brought close to the body portion so that a portion of the first internal sheet closer to the bottom side than the line in the vicinity of the line is aligned with the body portion.

This configuration can prevent the first internal sheet from peeling off from the main body.

According to the present disclosure, when contents are placed inside the container, the first internal sheet covers the sewn portion between the bottom and the body, preventing the contents from directly contacting the sewn portion and preventing the contents from leaking from the sewn portion.

FIG. 1 is a perspective view of a flexible container bag according to one embodiment. FIG. 1 is a schematic partial development view of a flexible container bag according to one embodiment. FIG. 4 is a partial detailed view of the area around the fixing line of the lower sheet. FIG. 11 is a vertical cross-sectional view showing a schematic configuration of a flexible container bag according to another embodiment. 1A is a partial vertical cross-sectional view showing a modified example around the fixing line, FIG. 1B is a partial front view showing another modified example around the fixing line, and FIG. 1C is a partial front view showing yet another modified example around the fixing line. 1A is a partial front view showing a modified example of the fixing line, FIG. 1B is a partial front view showing another modified example of the fixing line, and FIG. 1C is a partial front view showing yet another modified example of the fixing line.

Hereinafter, the embodiments will be described with reference to the drawings. In each drawing, the same or similar reference numerals are used for the same or corresponding parts, and duplicate explanations will be omitted.

First, referring to FIG. 1, a flexible container bag 1 (hereinafter referred to as "flexible container bag 1") according to one embodiment will be described. FIG. 1 is a perspective view of the flexible container bag 1. The flexible container bag 1 is a bag that contains and stores or transports objects to be contained (hereinafter also referred to as "contents") in, for example, the construction and civil engineering industry, waste disposal industry, recycling industry, manufacturing industry, agriculture, etc. Examples of objects to be contained in the flexible container bag 1 include soil, waste products, cuttings, powder, granular materials, etc., but various other objects that can be contained may also be used. Examples of powders and granular materials that can be contained in the flexible container bag 1 include mineral products such as cement and fine sand, industrial products such as red iron oxide powder and colored raw powder, wheat flour, starch, rice grains, etc.

The FIBC bag 1 is flexible and can be folded. Therefore, when not in use, it can be folded and stacked for storage. In addition, the FIBC bag 1 is provided with a hanging belt 15, so that it can be lifted and transported by a forklift or crane. The main part (main body 11) that constitutes the bag body of the FIBC bag 1 is constructed by sewing appropriately cut sheets. Generally, when a flexible container bag is lifted, a force acts in the direction of expanding the flexible container bag due to the weight and internal pressure of the contents contained inside. At this time, the seams of the sewn parts of the flexible container bag spread, and if the contents are small in particle size such as powder or granular matter, the contents may leak from the spread seams. The FIBC bag 1 according to this embodiment can prevent or reduce leakage of the contents even if the seams spread due to the weight of the contents, due to the configuration described below. The configuration of the FIBC bag 1 will be described below. The FIBC bag 1 includes a main body 11, a hanging belt 15, a lower sheet 21, and an upper sheet 22.

The main body 11 is a part that constitutes the main part of the FIBC bag 1, and has a trunk 12 and a bottom 13. The trunk 12 is made of a cylindrical sheet. The trunk 12 may be a long sheet cut to the required length, or a rectangular sheet formed into a cylindrical shape by joining a pair of opposing sides. The trunk 12 alone has both ends open. The bottom 13 closes one end of the trunk 12, which is formed into a cylindrical shape with both ends open. The bottom 13 is typically made of a sheet of the same material as the trunk 12. The bottom 13 is attached to one open end of the trunk 12 to form a bag-shaped main body 11. The bottom 13 can be of various shapes depending on the intended shape of the FIBC bag 1. For example, if the main body 11 is to be a cylindrical bag (so-called round type), the bottom 13 is formed in a circular shape, and if the main body 11 is to be a rectangular bag (so-called square type), the bottom 13 is formed in a rectangular shape (square or rectangular). In addition to being circular or rectangular, the bottom 13 may be an ellipse, a polygon such as a hexagon or octagon, or a diamond or any other shape.

The sheets forming the body 12 and bottom 13 are made of a material that can give flexibility to the main body 11, and typically a woven fabric made of polypropylene is used. The sheet is flexible and therefore foldable. The sheet is made of a polypropylene fabric woven vertically and horizontally with wide threads, and thus has the strength (tensile strength, etc.) required for the FIBC bag 1. Since it is difficult to weld or bond a polypropylene sheet with the strength required for the FIBC bag 1, the body 12 and bottom 13 are joined by sewing in the FIBC bag 1 according to this embodiment. Specifically, the outer periphery of the bottom 13 is sewn around the entire circumference of one open end of the body 12. Typically, polyester thread is used as the sewing thread that joins the body 12 and bottom 13, but other suitable material threads such as synthetic resin threads and hemp threads may also be used. In addition, because the FIBC bag 1 is flexible, it cannot stand upright without support or when it is not filled with contents, as shown in Figure 1, but for the sake of convenience, Figure 1 shows it in a self-supporting state.

The hoisting belt 15 is a belt-like member provided for lifting the FIBC bag 1 with a forklift or crane. The hoisting belt 15 is a long belt having a strength (tensile strength, etc.) that can withstand lifting the FIBC bag 1 filled with the planned contents. The hoisting belt 15 is typically made of polypropylene, but may be made of synthetic resin other than polypropylene or a material other than synthetic resin. In this embodiment, two sets of the hoisting belts 15 are attached to the main body 11. In this embodiment, the midpoint of each hoisting belt 15 is located on the side of the opening end face of the main body 11, and is fixed by sewing to the side of the body 12 at positions away from the midpoint in the direction of both ends. The part where the hoisting belt 15 is fixed to the body 12 is referred to as the "belt sewing part 16". The hoisting belt 15 may be fixed to the body 12 by a method other than sewing if the necessary strength can be ensured. The end of the hanging belt 15, which is closer to the end than the belt sewn part 16, extends in the axial direction of the cylindrical body 12 along the side of the body 12, then bends and extends along the surface of the bottom 13 toward the centroid of the bottom 13. In this embodiment, the end of the hanging belt 15 does not reach the centroid of the bottom 13, but is located between the centroid and the outer periphery of the bottom 13, and is fixed to the bottom 13 at that position. The end of the hanging belt 15 is typically fixed to the bottom 13 by sewing, but may be fixed by a method other than sewing. The FIBC bag 1 according to this embodiment has four belt sewn parts 16.

The four belt sewn portions 16 are typically arranged at equal intervals in the circumferential direction of the cylindrical torso 12. Furthermore, the four belt sewn portions 16 are typically arranged on the opening side of the main body 11 rather than the middle of the length of the torso 12 (the distance between both cylindrical end faces) in the cylindrical axial direction of the torso 12. The position of each belt sewn portion 16 in the cylindrical axial direction of the torso 12 (based on the centroid of the belt sewn portion 16) may be, for example, 1/5 to 1/3 of the length of the torso 12 from the end face on the opening side of the main body 11, or may be 1/4 of the length of the torso 12.

The lower sheet 21 is provided inside the main body 11 and covers the connection portion between the body 12 and the bottom 13 (hereinafter referred to as the "body bottom connection portion 14"), and corresponds to the first internal sheet. In this embodiment, a plastic film is used for the lower sheet 21. The film is a form of sheet because it is a thin sheet. The synthetic resin material of the plastic film constituting the lower sheet 21 can be polyethylene, polypropylene, polyvinyl chloride resin, polyester, nylon, and various other materials. The material of the lower sheet 21 can be appropriately determined taking into consideration the strength according to the application, the connection mode to the main body 11, etc. If the lower sheet 21 is made of a material similar to the material of the main body 11 (for example, polypropylene and/or polyethylene for the main body 11 of polypropylene), it is preferable because it makes it easier to recycle the FIBC bag 1 after use. There is no particular limit to the thickness of the lower sheet 21, but from the viewpoint of weight reduction, it is preferable to make it as thin as possible within the range where the necessary strength can be ensured.

In this embodiment, a rectangular film is used as the lower sheet 21. The width of the lower sheet 21 is equal to or greater than the inner periphery of the cylindrical body 12. The length of the lower sheet 21 (the length perpendicular to the width, in the direction in which the cylindrical axis of the body 12 extends) is at least longer than the bottom joint 14 when the lower sheet 21 is fixed to the body 12 and aligned along the inside of the main body 11. It is preferable that the length of the lower sheet 21 is long enough to cover the portion of the hanging belt 15 fixed to the bottom 13. In addition, the length of the lower sheet 21 may be a length extending from the bottom joint 14 to the centroid of the bottom 13 by about 100 mm to 300 mm when the main body 11 is filled with the contents and the lower sheet 21 is in contact with the main body 11 as a whole. Alternatively, instead of an absolute length, for example, it may be about 1/4 to 2/3, or 1/3 to 1/2, of the diameter of the bottom 13 if the bottom 13 is circular, or about 1/4 to 2/3, or 1/3 to 1/2, of one side of the bottom 13 if the bottom 13 is square, extending from the body bottom connection part 14 toward the centroid of the bottom 13.

The lower sheet 21 is fixed to the torso 12 at one end edge in the length direction or near the end edge, with the width direction arranged along the cylindrical inner circumference of the torso 12. The attachment position of the lower sheet 21 to the torso 12 (the position in the cylindrical axial direction of the torso 12) is a position where the end edge opposite to the end edge fixed to the torso 12 is located beyond the torso bottom connection part 14, as described above. The lower sheet 21 is typically fixed to the torso 12 over the entire cylindrical inner circumference of the torso 12 at the above-mentioned one end edge. The lower sheet 21 is not fixed to the main body 11 except for the end edge fixed to the torso 12. The lower sheet 21 has a free end opposite to the end edge fixed to the torso 12. Therefore, the lower sheet 21 is relatively easy to attach to the torso 12, and can follow the deformation of the main body 11 without creating unintended air pockets when the main body 11 is deformed by folding, etc. The lower sheet 21 may be rectangular or cylindrical.

Figure 2 is a schematic partial development of the FIBC bag 1, showing the internal state of the FIBC bag 1. In this embodiment, FIG. 2 partially shows the FIBC bag 1, which is formed cylindrically, developed in a state where part of the interior can be seen, and the bottom joint 14 is developed so as to be linear. As shown in FIG. 2, the lower sheet 21 is fixed to the body 12 by a fixing line 51 near one end edge. The end of the lower sheet 21 opposite the fixing line 51 is free to move freely. The fixing line 51 is a line by which the lower sheet 21 is fixed to the body 12. In this embodiment, the fixing line 51 is formed by sewing, but depending on the material of the body 12 and the lower sheet 21, it may be formed by welding, adhesive tape, adhesive, etc. As described above, the fixing line 51 is formed around the entire circumference of the cylindrical body 12.

3 shows the details of the area around the fixing line 51 of the lower sheet 21. In this embodiment, the lower sheet 21 is sewn to the body 12 with the film partially overlapped in the width direction to form tucks (folds), and multiple tucks are formed at appropriate intervals in the width direction. This configuration can prevent the contents from being filled into the FIBC bag 1 with the lower sheet 21 turned up. If the lower sheet 21 is fixed to the body 12 with a thin fixing line 51 without a tuck, the lower sheet 21, whose free end is on the opposite side to the fixing line 51, may turn up and the free end may remain positioned on the opening side of the FIBC bag 1. This condition may occur while the flexible FIBC bag 1 is folded or unfolded. In contrast, in the FIBC bag 1 according to this embodiment in which the lower sheet 21 has a tuck formed in it, when the FIBC bag 1 is unfolded, the free end of the lower sheet 21 extends toward the bottom 13 due to the presence of the tuck. This prevents the lower sheet 21 from remaining turned up. In addition, even if the lower sheet 21 is attached to the body 12 with multiple tucks formed, it is preferable that both ends in the width direction overlap, because this allows the lower sheet 21 to cover the entire body bottom connection part 14 without any gaps.

Returning to FIG. 1, the description of the FIBC bag 1 will be continued. The upper sheet 22 is provided inside the main body 11 and covers the belt sewn portion 16, and corresponds to a second internal sheet. The manner in which the upper sheet 22 covers the belt sewn portion 16 is also shown in FIG. 2. The upper sheet 22 is typically made of the same material as the lower sheet 21, but a different material that can be used as the lower sheet 21 may be used, or a material that is not used as the lower sheet 21 may be used. In this embodiment, a rectangular film is used as the upper sheet 22. The width of the upper sheet 22 is typically equal to or greater than the inner periphery of the cylindrical body 12. The length of the upper sheet 22 (the length in the direction perpendicular to the width and in the direction along which the cylindrical axis of the body 12 extends) is typically equal to or greater than the length of the belt sewn portion 16.

In this embodiment, the upper sheet 22 is arranged along the cylindrical inner circumference of the body 12 in a manner that covers the belt stitching portion 16 from the inside of the body 12, and is fixed to the body 12 at least at or near the end edge on the opening side of the FIBC bag 1. At this time, the position where the upper sheet 22 is fixed to the body 12 is between the end of the body 12 on the opening side of the FIBC bag 1 and the belt stitching portion 16. The upper sheet 22 is typically a free end on the bottom 13 side of the belt stitching portion 16. However, the upper sheet 22 may be connected to the main body 11 on the bottom 13 side of the belt stitching portion 16, and may be connected to the main body 11 entirely or partially (including intermittently) in the length direction (the axial direction of the cylindrical body 12). The upper sheet 22 can fulfill its function as long as it can cover each belt stitching portion 16. Therefore, the upper sheet 22 does not have to be large enough to cover all of the belt sewn portions 16 at once, and may be large enough to cover multiple belt sewn portions 16 individually or in any number. However, if the upper sheet 22 is configured to cover all of the belt sewn portions 16 at once, there is an advantage in that an increase in the number of parts can be suppressed, and manufacturing complexity can be suppressed.

The FIBC bag 1 configured as described above is typically folded and stored when not in use. Since the FIBC bag 1 is flexible, it can be relatively easily changed in shape and can be stacked, allowing multiple bags to be stored in a relatively small space. When using the FIBC bag 1, the bottom 13 is placed on the ground or floor, and the open surface of the FIBC bag 1 is lifted vertically upward to stretch the body 12. At this time, the hanging belt 15 may be used to stretch the body 12. When the body 12 is stretched in this way, the upper sheet 22 hangs down from the fixed portion to the body 12 toward the bottom 13 and covers each belt stitching portion 16. At this time, the upper sheet 22 typically hangs down along the body 12. When the body 12 is stretched, the lower sheet 21 also hangs down from the fixed portion to the body 12 toward the bottom 13. The lower sheet 21 has tucks, which prevents it from curling up and becoming unable to hang down toward the bottom 13. When the body 12 is stretched, the free end of the lower sheet 21 comes into contact with the bottom 13, but a gap may occur between the vicinity of the body bottom connection part 14 and the lower sheet 21.

When the body 12 is stretched as described above, the FIBC bag 1 becomes bag-shaped and can contain the contents. When the contents are poured into the bag-shaped FIBC bag 1, the contents pile up from the bottom of the FIBC bag 1. The contents poured into the FIBC bag 1 spread to the cylindrical inner wall of the body 12 as they pile up. When the contents pile up inside the FIBC bag 1 while spreading to the inner wall of the body 12, the lower sheet 21 is pressed against the body 12 and the bottom 13 by the internal pressure of the contents, and the entire sheet comes into contact with the body 12 and the bottom 13. In this way, the lower sheet 21 is sandwiched between the contents and the body 12 and the bottom 13, so that the contents do not directly hit the body bottom connection part 14 (seam), and leakage can be prevented even if the contents are small in particle size, such as powder. In addition, when the contents pile up and reach the height of the upper sheet 22, the upper sheet 22 is sandwiched between the contents and the belt sewing part 16. This prevents the contents from directly touching the belt sewn part 16, preventing leakage from the belt sewn part 16. The FIBC bag 1 filled with the contents can be stored as is, or it can be transported by lifting the hoisting belt 15 with a forklift or crane.

The FIBC bag 1 can also be suitably applied to a bag with a "discharge outlet" in which a discharge outlet is already formed in the bottom 13. A flexible container bag with a discharge outlet has a cut in the bottom in advance, and when the contents are loaded or transported, the cut is closed and the bundled bottom sheet is tied with a string or the like, and when the contents are discharged, the string or the like is untied to open the discharge outlet. In the FIBC bag 1 according to this embodiment, the end side of the lower sheet 21 provided inside the main body 11 opposite the fixed line 51 is a free end and is open, so that the contents can be discharged smoothly when the discharge outlet is opened. When the FIBC bag 1 is to have a discharge outlet, if there is a sewing line around the discharge outlet through which the contents may leak, it is preferable to form the lower sheet 21 to a size that can cover the sewing line with the lower sheet 21.

As described above, the FIBC bag 1 according to this embodiment has the lower sheet 21, so that leakage of contents from the body bottom connection part 14 can be suppressed. Also, the upper sheet 22 can be suppressed, so that leakage of contents from the belt stitching part 16 can be suppressed. In addition to the above, the FIBC bag 1 according to this embodiment has the following advantages. Compared to the method of putting an inner bag in a bag-shaped flexible container bag, it is possible to suppress the increase in costs. Also, compared to the method of sandwiching a cloth between the body and bottom of the flexible container bag or at the belt stitching part or the method of holding the seam with a string, it is possible to prevent leakage of contents equally or more efficiently with a simple configuration. When performing the sewing work in manufacturing the flexible container bag, it is only necessary to add the work of attaching the lower sheet 21 and the upper sheet 22, so it can be manufactured with a relatively simple additional work. Also, the FIBC bag 1 can be preferably adapted to have a discharge port.

Next, referring to FIG. 4, a flexible container bag 2 (hereinafter referred to as "FIBC bag 2") according to another embodiment will be described. FIG. 4 is a longitudinal cross-sectional view illustrating the schematic configuration of FIBC bag 2. FIBC bag 2 is normally used with the cylindrical axis of body 12 extending vertically, and therefore the longitudinal cross-section refers to a cross section parallel to the cylindrical axis of body 12 in this normal mode of use. FIBC bag 2 differs from FIBC bag 1 mainly in that it has a bottom cover sheet 25 as the first internal sheet instead of the lower sheet 21 (see FIG. 1) that FIBC bag 1 (see FIG. 1) has.

The bottom sheet 25, which corresponds to the first inner sheet, is fixed to the body 12 and extends beyond the body bottom connection part 14. The bottom sheet 25 is shaped to cover the entire bottom 13 in addition to the lower part of the body 12 inside the FIBC bag 2. In other words, the bottom sheet 25 is typically formed in a bag shape with one end face closed, formed in substantially the same shape as the shape of the lower part of the main body 11. Here, substantially the same shape is intended to be the same shape to the extent that no unnecessary gap is formed between the main body 11 and the bottom sheet 25 when the contents put into the FIBC bag 2 are piled up in the FIBC bag 2. Note that the unnecessary gap is a gap that will cause the bottom sheet 25 to be damaged by the force of the contents inside the bottom sheet 25 trying to move toward the gap.

The bottom cover sheet 25 is made of a liquid-proof material. Here, liquid-proof means that the material has the ability to prevent the passage of liquids that exceed the allowable range in light of the use of the FIBC bag 2. Materials that can be used to form the bottom cover sheet 25 include polyethylene, polypropylene, polyvinyl chloride resin, polyester, nylon, and other synthetic resins. Materials that can be used to form the bottom cover sheet 25 include various synthetic resins, as well as woven or nonwoven fabrics coated with a liquid-proof material.

The bottom cover sheet 25 is fixed to the body 12 by a fixing line 51 at a position (typically near the edge) away from the portion covering the bottom 13, similar to the lower sheet 21 (see FIG. 1). The distance from the body bottom connection part 14 to the fixing line 51 should be determined taking into consideration the possible liquid depth in the environment in which the FIBC bag 2 is placed. For example, if there is a possibility that rainwater will accumulate around the placed FIBC bag 2 by up to 50 mm, the distance from the body bottom connection part 14 to the fixing line 51 should be set to a distance exceeding 50 mm. In this way, the distance from the body bottom connection part 14 to the fixing line 51 can be, for example, 30 mm, 50 mm, 100 mm, 150 mm, or 200 mm depending on the environment in which the FIBC bag 2 is placed, and may be a distance exceeding 200 mm. Alternatively, the distance from the bottom connection 14 to the fixed line 51 may be 1.1 to 2.0 times, 1.2 to 1.5 times, or about 1.3 times the maximum liquid depth that can occur around the FIBC bag 2. Depending on the situation, the distance may be more than twice as long.

Other than the above, the FIBC bag 2 is similar to the FIBC bag 1 (see FIG. 1), including the provision of the hanging belt 15 and the upper sheet 22. In the FIBC bag 2 configured in this way, the entire portion of the contents piled up at the bottom of the loaded contents is covered by the liquid-proof bottom sheet 25. Therefore, even if liquid such as rainwater accumulates around the FIBC bag 2, the contents loaded inside the FIBC bag 2 can be protected from being submerged (soaked in liquid). Due to the structure of the FIBC bag 2, the contents loaded inside can also be made to have a high liquid content (the proportion of liquid contained in the contents). In this case, the presence of the bottom sheet 25 can prevent liquid seeping out of the contents from leaking out of the FIBC bag 2.

In the above explanation, the FIBC bags 1 and 2 are provided with an upper sheet 22, but if there is no leakage of the contents from the belt stitching 16, the upper sheet 22 may be omitted. On the other hand, for example, if the body 12 is formed by sewing together multiple cylindrical sheets, it is advisable to provide a sheet that covers the joined parts from the inside in the same manner as the upper sheet 22.

In the above description, the sheets forming the body 12 and bottom 13 are woven polypropylene fabrics, but polyethylene or other synthetic resins may be used depending on the application of the FIBC bags 1 and 2. Furthermore, the sheets are not limited to woven fabrics and may be nonwoven fabrics.

In the above description, the first internal sheet is the lower sheet 21 made of a plastic film, but it may be made of a plastic sheet thicker than a film, or may be made of a woven or nonwoven fabric other than a film. In other words, the first internal sheet may be made of a single material stretched into a film, or may be made of a woven or nonwoven fabric made of a single or multiple materials (e.g., polypropylene/polyethylene woven or nonwoven fabric). The material is not limited to plastic, and natural materials such as cotton, wool, and hemp may be used. However, taking into consideration strength, flexibility, weight, etc., it is preferable that the first internal sheet is made of a plastic film.

In the above description, the lower sheet 21 (first internal sheet) and the upper sheet 22 (second internal sheet) are separate and fixed to the main body 11 individually. However, a long sheet formed by integrally forming the lower sheet 21 and the upper sheet 22 may be used as both the first internal sheet and the second internal sheet. Similarly, when the bottom cover sheet 25 is provided instead of the lower sheet 21, a sheet formed by integrally forming the bottom cover sheet 25 and the upper sheet 22 may be used as both the first internal sheet and the second internal sheet. In this way, when the lower sheet 21 or the bottom cover sheet 25 and the upper sheet 22 are integrally formed, the body bottom connection part 14 and the belt sewing part 16 can be integrally covered. Therefore, when a material having airtightness and liquid resistance is used as the integrally formed sheet, it is possible to block ventilation with the outside and prevent water from getting in from the outside and the contents (powder) from leaking from the stitches of the woven fabric of the main body 11. That is, in this case, the same effect as when the main body 11 is laminated (coated) can be obtained. In addition, in either case where the lower sheet 21 or the bottom cover sheet 25 and the upper sheet 22 are integrally formed or separately formed, an inlet (not shown) may be integrally formed with the upper sheet 22. The inlet is generally a flexible cylindrical member attached to the open end of the main body 11 and provided to extend upward (to the opposite side to the bottom 13). The inlet typically has the same contour (cylindrical circumference) as the trunk 12. In addition, since the inlet generally does not require the same strength as the main body 11, a relatively thin and lightweight material (e.g., woven fabric of polypropylene or polyethylene) is used, but other materials or the same material as the main body 11 may be used. When filling the main body 11 with the contents, the inlet is extended upward and used to function as a guide to guide the contents to the main body 11, and after the main body 11 is filled with the contents, it is bundled and functions as a lid for the main body 11. If the upper sheet 22 and the injection port are formed as one unit, the length of the sheet portion should be the sum of the length usable as the injection port and the length that can cover the belt sewing portion 16, and the middle part of the length should be fixed to the upper part of the torso portion 12.

In the above explanation, the lower sheet 21 (first internal sheet) is fixed to the torso 12 with multiple tucks formed, but as a measure to prevent the lower sheet 21 from curling up, it may be fixed to the torso 12 in the manner described below.

As an example, as shown in FIG. 5(A), the edge of the lower sheet 21 on the fixing line 51 side may be folded back toward the inside of the main body 11, and the two folded and overlapping films may be fixed together to the trunk 12. In this way, the film at the folded back portion located on the inside of the main body 11 can hold down the film extending toward the bottom 13, preventing the film extending toward the bottom 13 from turning over.

As another example, as shown in FIG. 5(B), the overlapping member 53 may be overlapped on the lower sheet 21 at the position where the lower sheet 21 is fixed, and then the overlapping member 53 and the lower sheet 21 may be fixed to the body 12 together. At this time, the end of the lower sheet 21 is sandwiched between the body 12 and the overlapping member 53. The overlapping member 53 is typically a patch having a predetermined width, but may be a resin such as a film or a plastic sheet, or may be a metal. The predetermined width (the length in the direction perpendicular to the direction in which the fixing line 51 extends) here is a width that allows the lower sheet 21 to be pressed along the body 12, and can be an appropriate width depending on the hardness of the lower sheet 21. In addition, the overlapping member 53 is typically a long and narrow rectangular member formed into a ring shape so that it can be overlapped on the lower sheet 21 over the entire circumference of the cylindrical body 12, as shown in FIG. 5(B). In addition, the overlapping member 53 may be composed of a plurality of small pieces, as shown in FIG. 5(C), and these may be intermittently provided in the cylindrical circumferential direction of the body 12. As shown in FIG. 5(B) or FIG. 5(C), by using an overlapping member 53, the film extending toward the bottom 13 can be held down by the overlapping member 53, and the film extending toward the bottom 13 can be prevented from turning over.

As another example, as shown in FIG. 6(A), in addition to the fixed line 51 extending in the circumferential direction of the cylindrical body 12 described above, fixed lines 52 shorter than the fixed line 51 may be provided at intervals in the circumferential direction of the cylindrical body 12. Here, the fixed line 51 can be seen as a main line, and the fixed line 52 as a short line. The fixed line 52 is provided near the fixed line 51. Here, "near the fixed line 51" includes contact with the fixed line 51. In the example shown in FIG. 6(A), the fixed line 52 is perpendicular to the fixed line 51, but may have any angle (e.g., 15°, 30°, 45°, 60°, 75°, etc.) with respect to the fixed line 51, or may be parallel to the fixed line 51. It is preferable that the part of the fixed line 52 farthest from the fixed line 51 is as close as possible to the fixed line 51 within a range in which the curling of the lower sheet 21 can be appropriately suppressed. From this perspective, the length of the fixed line 52 and the range near the fixed line 51 can be determined.

Alternatively, as shown in FIG. 6(B), the fixing line 51 may extend in a curved shape in the circumferential direction of the cylindrical body 12. In the example shown in FIG. 6(B), the fixing line 51 is curved with an irregular waveform, but it may also be curved with a regular waveform such as a sine wave. Furthermore, the fixing line 51 is not limited to a curved shape, and may also be a broken line shape. Examples of broken lines include a square wave shape, a triangular wave shape, and a sawtooth wave shape.

Alternatively, as shown in FIG. 6(C), the fixing line 51 may have a predetermined width. The predetermined width here is a width that allows the portion of the lower sheet 21 near the fixing line 51 on the bottom 13 side of the fixing line 51 to move closer to the body 12 so as to follow the body 12. By making the width of the fixing line 51 wider like a band rather than narrow like a line, it is possible to prevent the lower sheet 21 from curling up away from the body 12 due to the elasticity of the lower sheet 21. By devising the fixing line 51 as shown in FIG. 6(A) to FIG. 6(C), it is possible to prevent the film extending toward the bottom 13 from curling up.

The above-mentioned anti-turning measures shown in Figures 5(A) to 6(C) can be applied not only to the lower sheet 21, but also when fixing the upper sheet 22, the long sheet, and the bottom cover sheet 25 to the main body 11.

1, 2 Flexible container bag
11 Main body 12 Torso 13 Bottom 15 Suspension belt 16 Belt sewing part 21 Lower sheet (first inner sheet)
22 Upper sheet (second inner sheet)
25 Bottom cover sheet (first inner sheet)

Claims (5)

A main body portion includes a body portion formed of a sheet in a cylindrical shape and a bottom portion formed of a sheet that closes one of the cylindrical openings of the body portion, the bottom portion being connected to the body portion by sewing;
a first internal sheet provided inside the main body, the first internal sheet being fixed to the trunk and having a length that exceeds a length from a position fixed to the trunk to a sewn portion between the bottom and the trunk;
Flexible container bag. The first inner sheet has an end portion extending beyond the sewn portion between the bottom portion and the body portion that is a free end.
The flexible container bag according to claim 1. The first internal sheet has a tuck formed by partially overlapping the first internal sheet in the cylindrical circumferential direction of the body portion at a portion fixed to the body portion.
The flexible container bag according to claim 1 or 2. The first internal sheet is made of a liquid-proof material and is formed into a bag shape that is closed in a state where it covers the bottom portion.
The flexible container bag according to claim 1. A hanging belt connected to the torso by sewing;
a second internal sheet provided inside the main body, the second internal sheet being fixed to the torso on the opposite side to the bottom with respect to a sewing position of the hanging belt to the torso, the second internal sheet having a length exceeding a length from a position fixed to the torso to a sewing portion between the torso and the hanging belt;
The flexible container bag according to claim 1 or 2.