Sealed bags

Abstract

To provide a sealed bag which can reduce manufacturing costs, has small resistance even when deaerated by hand, is easy to handle, and has a high degree of freedom in design. [Solution] In the sealed bag 1, a plurality of sheets 11, 12, 31, 32 are stacked and bonded to form an article storage section (sealed section) 2 and an air passage section (ventilation path) 3 that is continuous with the space of the article storage section 2. The sheets used are a front sheet 11, a rear sheet 12, and a valve body sheet 31 disposed between the sheets 11, 12. Distance retaining members 32x, 32y such as filaments are disposed between the bag sheets 11, 12 and the valve body sheet 31.

Description

[Technical field]

[0001] The present invention relates to a sealed bag whose interior can be sealed in an airtight state. [Background technology]

[0002] Conventionally, sealed bags have been used that can seal the sealed portion in an airtight state, and that connect the sealed portion to the outside of the bag in a breathable manner in order to exhaust various gases such as air present in the sealed portion to the outside of the bag and maintain that state, or to fill the sealed portion with various gases and maintain that state, and that allow air to pass in one direction while blocking air flow in the other direction by opening and closing an airflow passage space, which is the space through which the gas passes, when exhausting or filling the gas.

[0003] One type of the above-mentioned sealed bag is a compression bag 101, 201, which is a bag body in which required parts of a flexible resin sheet are bonded by heat sealing or the like to form a sealed part 102, 202 having a space surrounded by the sheet, and which can expel gas present in the sealed part 102, 202 to the outside of the bag and maintain that state.

[0004] The compression bags 101, 201 are provided with openings 103, 203 for inserting and removing the article M into and from the sealed portions 102, 202. The openings 103, 203 are also provided with closing means 104, 204 such as a zipper for sealing the openings 103, 203.

[0005] There are various embodiments of this compression bag, but they can be roughly divided into the following two types of compression bags 101 and 201. First, there is a method described in Japanese Patent Publication No. 9-309544. A simple illustration of this is a compression bag 101 having a check valve 105 as shown in Fig. 16. In this example, the check valve 105 used in this compression bag 101 includes an outer tube 107 having flexible resin outer tube sheets 107a, 107b in a flat cylindrical shape so that the space of the sealed portion 102 is continuous with the outside of the compression bag 101, and a valve body sheet 106 made of a flexible resin sheet provided inside the outer tube 107 as shown in Fig. 16(B).

[0006] The valve sheet 106 allows airflow F1 to pass from the sealed portion 102 to the outside of the compression bag 101, while blocking airflow F2 in the opposite direction. This check valve 105 maintains the degassed state even after the sealed portion 102 has been degassed. This compression bag 101 can maintain a degassed state after storing an item M in the sealed portion 102 and then discharging the air in the sealed portion 102 to the outside of the bag through the check valve 105 with the closing means 104 closed. This is particularly effective for items such as clothing and blankets that contain air and become voluminous, and because the air contained in the item M can be discharged to the outside of the compression bag 101, the compression bag 101 containing the item M can be stored in a compact form. Therefore, this compression bag 101 is suitable as a storage bag for clothing and the like, or as an organization bag for travel.

[0007] However, this check valve 105 is manufactured separately from the bag sheets 102a, 102b that constitute the sealed portion 102, and is later incorporated when forming the sealed portion 102. This requires separate processes for manufacturing the check valve 105 and incorporating it into the sealed portion 102, making the manufacturing process for the compression bag 101 complicated. In addition, this also causes an increase in manufacturing costs due to the need to use special manufacturing equipment.

[0008] 16(B), the bag sheets 102a, 102b constituting the sealed portion 102 are bonded to the outer cylinder portion 107 of the check valve 105. This heat seal 108 is formed by pressing the bag sheets 102a, 102b from both sides with a heated mold while the check valve 105 is sandwiched between the bag sheets 102a, 102b, so as to cross the check valve 105.

[0009] Therefore, in order to prevent the outer cylinder 107 and the valve sheet 106 of the check valve 105 from being heat-sealed together, for example, a paint 106b is applied to the surface 106a of the valve sheet 106 that faces the inner surface of the outer cylinder 107 to prevent this surface 106a from melting due to the heat during heat sealing. However, even though the paint 106b is applied in this manner, the inner surface of the outer cylinder sheet 107a of the outer cylinder 107 melts slightly due to the heat during heat sealing and the pressure of the mold used for heat sealing, so that the outer cylinder 107 and the valve sheet 106 are actually lightly heat-sealed (light heat seal 109). Although this light heat seal 109 can be removed with a weak external force, when the compression bag 101 is used for the first time, the internal pressure of the sealed part 102 increases until the outer cylinder part 107 and the valve body sheet 106 separate and the check valve 105 opens due to the light heat seal 109 being removed, which causes a large resistance during degassing and takes a very long time, and in some cases, there is a risk that the bag sheets 102a, 102b of the sealed part 102 may burst. These are particularly noticeable problems when degassing by pressing the sealed part 102 by hand.

[0010] Meanwhile, another type of compression bag 201 is disclosed in U.S. Patent No. 6,116,781, as shown in Fig. 17. This type has an intermediate sheet 206 sandwiched between two opposing bag sheets 202a, 202b, and a check valve 205 formed with an air passage for deaeration between the bag sheets 202a, 202b and the intermediate sheet 206. This check valve 205 performs a check function by the bag sheets 202a, 202b and the intermediate sheet 206 coming into close contact with each other. In this compression bag 201, the check valve 205 is formed integrally from the beginning, and has the advantage that it can be manufactured in one process, unlike the compression bag 101. In addition, the problem of the formation of a light heat seal 109 that occurs when a separate check valve 105 is incorporated as described above does not occur. However, since this compression bag 201 is merely made by sandwiching the intermediate sheet 206 between the bag sheets 202a, 202b, the non-return action is incomplete, and it is impossible to reliably maintain the deaerated state of the sealed portion 202. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Publication No. 9-309544 [Patent Document 2] U.S. Patent No. 6,116,781 Summary of the Invention [Problem to be solved by the invention]

[0012] In view of the above, the objective of the present invention is to provide a compression bag that can be manufactured in a single process, thereby reducing manufacturing costs, can reliably maintain the degassed state of the sealed portion, and is easy to handle because it has little resistance when degassing by hand. [Means for solving the problem]

[0013] In order to solve the above problems, the present invention provides a sealed bag 1 capable of sealing the sealed part 2 in an airtight state. This sealed bag has an air passage 3 that connects the sealed part 2 to the outside of the bag in a breathable manner in order to exhaust gas present in the sealed part 2 to the outside of the bag and maintain that state, or to fill the sealed part 2 with gas and maintain that state. This sealed bag has a structure of the air passage 3 that allows the passage of air in one direction and blocks the air flow in the other direction by opening and closing the air flow passage space 3a, which is the space through which the gas passes, when exhausting or filling the gas.The sealing bag 1 of the present invention comprises bag sheets 11, 12 made of flexible resin arranged opposite to each other, at least one valve body sheet 31 made of flexible resin arranged between the bag sheets 11, 12 and partly bonded to at least one of the bag sheets 11, 12 at an adhesive part 31b, and a movable part 31c other than the adhesive part 31b is movable, and a spacing member 32 arranged between the bag sheets 11, 12 to which the valve body sheet 31 is bonded as described above and the valve body sheet 31, and this ventilation path 3 is defined by a pair of vent passage side seals 33 in which the bag sheets 11, 12, the valve body sheet 31, and the spacing member 32 are bonded together, and one end of this vent passage 3 is connected to the sealed portion 2, and the other end is connected to the outside of the bag. The vent passage side seals 33 are formed along the forward air flow F1, which is the direction in which gas is allowed to pass through the vent passage, and the bonded portion 31b of the valve body sheet 31 is disposed on the upstream side of the forward air flow F1, and the movable portion 31c is disposed on the downstream side of the same. In the movable portion 31c, the surface facing the inner surfaces 11a, 12a of the bag sheets 11, 12 to which the valve body sheet 31 to which the movable portion 31c belongs is bonded is a separation surface 31d, and the surface opposite to the separation surface 31d is a contact surface 31a. The spacing member 32 is disposed between the inner surfaces 11a, 12a of the bag sheets 11, 12 and the separation surface 31d of the valve body sheet 31, so that the spacing member 32 is in contact with the inner surfaces 11a, 12a of the bag sheets 11, 12 at least in a part between the inner surfaces 11a, 12a of the bag sheets 11, 12 and the separation surface 31d of the valve body sheet 31. The valve sheet 31 can maintain a 2-minute interval, and for a forward airflow F1, the valve sheet 31 separates from the bag sheets 11, 12 or the other valve sheet 31 that faces the contact surface 31a of the valve sheet 31, opening the airflow passage space 3a, and for a reverse airflow F2 that is the opposite to the forward direction, the valve sheet 31 comes into contact with the bag sheets 11, 12 or the other valve sheet 31 that faces the contact surface 31a of the valve sheet 31, closing the airflow passage space 3a. Another feature is that the spacing member 32 is one selected from a filament, a nonwoven fabric, a net, a woven fabric, paper, and a resin sheet that has no air permeability. Effect of the Invention

[0014] The present invention has the following excellent effects: The invention described in claim 1 of the present application makes it possible to maintain a gap of the spacing retaining member 32 between at least one of the bag sheets 11, 12 and the valve disk sheet 31, at least in part between the inner surfaces 11a, 12a of the bag sheets 11, 12 and the separating surface 31d of the valve disk sheet 31, thereby making it easier for the valve disk sheet 31 to close the air passage 3, effectively preventing backflow of air in the air passage 3, and providing a sealed bag with an air passage structure that can maintain the deaerated state of the sealed portion 2 for a long period of time. Furthermore, when the spacing member 32 is made filament-like, it is possible to reduce the dimension in the direction along the air flow of the movable portion 31c of the valve sheet 31, which is the portion that contacts the spacing member 32, and this makes it possible to reduce the width dimension of the entire valve sheet 31. Furthermore, since the spacing member 32 can be freely supplied from an oblique direction or an orthogonal direction by bending it, this is also advantageous in terms of the layout of the manufacturing device. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1(A) is a plan view showing a compression bag as an example of an embodiment of the present invention, and FIGS. 1(B) and 1(C) are end views taken along the line AA in FIG. 1(A), with the front-to-rear direction exaggerated. [Diagram 2] 2(A) is an end view taken along the line B-B of FIG. 1(A), where FIG. 2(A) corresponds to the state shown in FIG. 1(B), and FIGS. 2(B) and (C) correspond to the state shown in FIG. 1(C). [Diagram 3] FIG. 2 is an exploded perspective view showing the configuration of a compression bag in one embodiment of the present invention. [Figure 4] 4(A) and (B) are explanatory end views showing an air passage of a compression bag in another example of an embodiment of the present invention. [Diagram 5]FIG. 5(A) is an enlarged plan view of a main portion showing an air passage of a compression bag in another example of an embodiment of the present invention, and FIG. 5(B) is an end view taken along the CC arrow in FIG. 5(A). [Figure 6] 6(A) and (B) are explanatory end views showing an air passage of a compression bag in another example of an embodiment of the present invention. [Figure 7] 7(A) and (B) are explanatory views showing the configuration of the front sheet used in the evacuable bag shown in FIG. 6(A). [Figure 8] 8(A) and (B) are explanatory end views showing an air passage of a compression bag in another example of an embodiment of the present invention. [Figure 9] FIG. 9(A) is a plan view showing a compression bag which is another example of an embodiment of the present invention, and FIGS. 9(B) and (C) are end views taken along the line DD in FIG. 9(A), in which the front-rear direction is exaggerated. [Figure 10] 9(C) is an end view taken along the line DD in FIG. 9(A) and showing the actual state of the state shown in FIG. 9(C). [Figure 11] FIG. 11 is a plan view showing a compression bag as yet another example of an embodiment of the present invention. [Figure 12] FIG. 11 is a plan view showing a compression bag as yet another example of an embodiment of the present invention. [Figure 13] 13(A) and (B) are explanatory end views showing an air passage of a compression bag which is yet another example of an embodiment of the present invention. [Figure 14] FIG. 14(A) is an explanatory end view showing an air passage of a compression bag which is yet another example of an embodiment of the present invention, and FIG. 14(B) is an explanatory perspective view showing a spacing member used in this air passage. [Figure 15] FIG. 15(A) is an explanatory diagram in a plan view showing a manufacturing process of a compression bag in one embodiment of the present invention, and FIG. 15(B) is an explanatory diagram in a front view of the same. [Figure 16] FIG. 16(A) is a plan view showing a compression bag in an example of a conventional embodiment, and FIG. 16(B) is an end view taken along the line EE in FIG. 16(A). [Figure 17] FIG. 13 is an exploded perspective view showing the configuration of a compression bag in another example of a conventional embodiment. [Figure 18] FIG. 18(A) is a plan view of a compression bag according to an example of an embodiment of the present invention used in the experiment, and FIGS. 18(B) and (C) are plan views of commercially available compression bags used for comparison. BEST MODE FOR CARRYING OUT THEINVENTION

[0016] The following describes a compression bag as an example of a sealing bag according to an embodiment of the present invention. In the claims and specification of the present invention, expressions indicating positions and directions such as "front and back", "up and down, left and right", and "vertical and horizontal" are determined for the sake of convenience based on the illustrated state in order to specify positions, and the present invention should not be interpreted as being limited to the positional relationship as described.

[0017] As shown in Figures 1 and 3, the compression bag 1 in this example uses as its constituent parts bag sheets (front bag sheet 11, rear bag sheet 12) which are vertically elongated rectangular as shown, valve body sheets 31 (front valve body sheet 31x, rear valve body sheet 31y) which are horizontally elongated rectangular as shown and have a smaller vertical dimension than the bag sheets 11, 12, and spacing retaining members 32 (front spacing retaining member 32x, rear spacing retaining member 32y) which are sheet-like bodies whose vertical dimension is smaller than that of the valve body sheet 31. Each of the sheets 11, 12, 31, and 32, which are the above-mentioned constituent members, is flexible, and as shown in FIG. 15, a long sheet that is continuous without any breaks in the longitudinal direction is used. As described below, predetermined positions of each of the sheets 11, 12, 31, and 32 are bonded by heat sealing or the like and then cut to form a bag body with a sealed portion 2 and an air passage 3 defined therein. Resin sheets are used for the bag sheets 11, 12 and the valve body sheet 31, and examples of the resin sheets include a laminate of multiple resin films, such as a laminate of multiple polyethylene films bonded together, or a laminate of a polyethylene film and a nylon film bonded together. Such a sheet of multiple resin films laminated together is more common than a sheet made of a uniform material. Also, while polyethylene films have heat-sealing properties, nylon films do not, so when heat-sealing is performed as described below, the polyethylene films in the resin sheets must be placed opposite each other.

[0018] The outer portion of the compression bag 1 is formed by the bag sheets 11, 12 arranged opposite to each other as shown in Fig. 3. The sealed portion 2 is formed between the front bag sheet 11 and the rear bag sheet 12, and has a space capable of storing an article M. The air passage 3 forms an airflow passage space 3a that continues from the sealed portion 2 to the outside of the bag so that gas (air) can pass through when deaeration is performed from the space inside the sealed portion 2 to the outside of the bag.

[0019] Specifically, to explain this together with Figure 1, the sealing portion 2 in this example is formed by bonding bag sheets 11, 12 and a valve body sheet 31 together, and is the portion above the sealing portion partition seal 14, defined by the sealing portion partition seal 14 extending in the left-right direction as shown in Figure 1 (B) and the bag side seals 16 that define both the left and right ends of the sealed bag 1, and the air passage 3 is defined by the air passage side seal 33, which will be described later, of the air passage forming portion 30, which is the lower portion defined by the sealing portion partition seal 14. Needless to say, the above-mentioned sealed portion partition seal 14 is not provided between the sealed portion 2 and the air passage 3. And the bottom seal 15 formed in this example to define the lower end of the sealed bag 1 is also not provided in the air passage 3. Therefore, the space inside the sealed portion 2 and the airflow passage space 3a of the air passage 3 are in communication, and the gas (air) present in the sealed portion 2 can be degassed to the outside of the bag. In this example, the above-mentioned sealing portion partition seal 14 is formed by overlapping it at the same position in the vertical direction as shown in the figure with the adhesive portion 31b, which is a seal that bonds the bag sheets 11, 12 and the valve sheet 31 as shown in the figure, but it is sufficient that at least the front bag sheet 11 and the rear bag sheet 12 are bonded together, and it may be formed by shifting it from the adhesive portion 31b.

[0020] As shown in FIG. 1(A), the upper end edges of the front bag sheet 11 and the rear bag sheet 12 are not bonded to each other, forming an opening 1a. An article M can be put in and taken out of the sealed portion 2 through this opening 1a. In this embodiment, a closing means 4 is provided at the opening 1a, and the opening 1a can be closed in an airtight state. The closing means 4 in this embodiment is a resin zipper having a convex portion on one side of the bag sheets 11 and 12 and a concave portion on the other side, and the opening 21 can be closed by fitting the convex portion and the concave portion together. However, the closing means 4 is not limited to this, and various closing means can be used. In some cases, after the article M is stored in the sealed portion 2 through this opening 1a, the opening 1a may be bonded by heat sealing or the like to make it unopenable, or in the case of a sealed bag 1 in which the sealed portion 2 is filled with gas through the passage portion 3, the opening 1a may not be provided from the beginning, and the passage portion 3 may be the only portion through which the gas can pass.

[0021] In this example, as shown in Figure 1(A), the valve sheet 31 is arranged in the lower part of the compression bag 1, that is, in the air passage forming part 30, which is the lower part defined by the above-mentioned sealed part partition seal 14, and as shown in Figure 1(B), two valve sheets 31 (31x, 31y) are arranged between the front bag sheet 11 and the rear bag sheet 12.

[0022] As described above, the air passage 3 has an airflow passage space 3a that continues from the space inside the sealed portion 2 to the outside of the compression bag 1 and is opened during degassing. In this example, this airflow passage space 3a is the space between the two valve body sheets 31 as shown in Figures 1(B) and 2(A). 1(B)(C), the front bag sheet 11 and the rear bag sheet 12 are drawn far apart to facilitate understanding of the air passage 3, but the front bag sheet 11 and the rear bag sheet 12 are actually closer together because they are bonded together with the valve sheet 31 and the spacing member 32 sandwiched therebetween as shown in FIG. 3 (the same is true for other figures for the explanatory diagram of the end view showing the air passage 3), and in the portion where the valve sheet 31 and the spacing member 32 are not present, the inner surfaces 11a and 12a of the bag sheets 11 and 12 are close enough to abut against each other, and in the portion where the valve sheet 31 is present, the opposing valve sheets 31 (31x, 31y) are also close enough to abut against each other. Only when the forward airflow F1, which is the airflow from the sealed portion 2 to the outside of the bag, passes through, the valve sheets 31 (31x, 31y) are separated from each other, and the airflow passing space 3a is opened. As shown in FIG. 1(A), the air passage 3 is defined on all four sides by the sealed portion 2 at the top, the lower side by the lower edge of the compression bag 1 at the bottom, and two air passage side seals 33 formed in the vertical direction to bond the bag sheets 11, 12, the valve body sheet 31, and the spacing retaining member 32 together on the left and right sides, with the upper end connected to the sealed portion 2 and the lower end coinciding with the lower end of the sealed bag 1 and connected to the outside of the bag.

[0023] In this example, a portion of the front valve sheet 31x arranged on one side, i.e., the front side (upper side in FIG. 1(B)), is adhered to the inner surface 11a of the front bag sheet 11, and a portion of the rear valve sheet 31y arranged on the other side, i.e., the rear side (lower side in FIG. 1(B)), is adhered to the inner surface 12a of the rear bag sheet 12. Here, the portion of the valve sheet 31 adhered to the front bag sheet 11 and the rear bag sheet 12 is the adhesive portion 31b. This adhesive portion 31b is arranged on the upstream side of the valve sheet 31 in the forward air flow F1, and in this example, it is the end portion of the valve sheet 31 on the sealing portion 2 side (the upper end portion shown in FIG. 1(A)). In other words, the front valve sheet 31x is not adhered to the front bag sheet 11 except at the adhesive portion 31b and the above-mentioned air passage side seal 33, and the rear valve sheet 31y is not adhered to the rear bag sheet 12 except at the adhesive portion 31b and the air passage side seal 33. The movable part 31c is located downstream of the adhesive part 31b in the forward airflow F1 (in this example, the opposite side to the sealing part 2, the lower side shown in FIG. 1(A)). The movable part 31c is movable within a range from a state in which the airflow passing space 3a is opened and the forward airflow F1 can pass through, as shown in FIG. 1(B) and FIG. 2(A), to a state in which the airflow passing space 3a is closed, as shown in FIG. 1(C) and FIG. 2(B) and (C). As a result, the movable part 31c of the valve sheet 31 (for example, the front valve sheet 31x) rises up from the front bag sheet 11 and the rear bag sheet 12 to which the valve sheet 31 is adhered, and comes into close contact with another valve sheet 31 (for example, the rear valve sheet 31y), thereby closing the airflow passing space 3a. In addition, in the movable part 31c of the valve body sheet 31, the surface facing the inner surfaces 11a, 12a of the bag sheets 11, 12 to which the valve body sheet 31 to which this movable part 31c belongs is adhered is the separation surface 31d, and the surface opposite this separation surface 31d is the contact surface 31a, and when the air flow passage space 3a is closed, the contact surface 31a of the valve body sheet 31 on one side and the contact surface 31a of the valve body sheet 31 on the other side are in close contact with each other, as shown in Figure 1 (C). The location where the adhesive portion 31b is formed is not limited to the end of the valve body sheet 31 on the sealing portion 2 side as in this example, but may be formed away from the end of the valve body sheet 31. Therefore, other than the movable portion 31c, a portion that is not adhered to the bag sheets 11, 12 may be provided to the extent that degassing is not hindered.

[0024] In the case of a compression bag 1 that is used by degassing the air in the sealed portion 2, the valve body sheet 31 is brought into close contact when the inside of the sealed portion 2 is reduced in pressure due to degassing. In other words, a pressure difference exists between the outside of the bag (positive pressure) and the inside of the sealed portion 2 (negative pressure), and due to this pressure difference, as shown in FIG. 1(C), a suction force P acts on the valve body sheet 31, which draws it toward the sealed portion 2 on the negative pressure side. Since the valve body sheet 31 is made of a flexible resin, it is easily deformed by the suction force, and the contact surfaces 31a of the valve body sheet 31 are brought into close contact with each other. At the same time, the outside air does not flow back to the sealed portion 2, but always enters the dead-end portion 3b between the bag sheets 11, 12 and the valve body sheet 31 and stagnates therein. Therefore, it is impossible for the air flow F2 in the opposite direction to continue to flow back to the sealed portion 2 without the air flow space 3a being closed, and the air flow space 3a is reliably closed.

[0025] In contrast to the compression bag 1 in this example, in the case of a sealed bag 1 in which gas is filled in the sealed portion 2, the pressure inside the sealed bag 2 is higher than that outside the bag, and a pressure difference opposite to that described above exists. However, due to this pressure difference, the contact surfaces 31a of the valve body sheets 31 contact each other in the same manner as described above, and at the same time, the gas filled inside the sealed portion 2 always enters the dead end portion 3b and stagnates there without flowing back out to the outside of the bag, so that the air flow passage space 3a is reliably closed.

[0026] On the other hand, the airflow F1 in the forward direction, which is the opposite direction to the above, flows out from the sealed portion 2 to the outside, and pushes apart the space between the two valve bodies 31, as shown in FIG. 1(B), opening the airflow passing space 3a and flowing. Here, in the structure of the ventilation passage 3 of the present invention, as described later, the heated metal mold for heat sealing is not pressed against the ventilation passage 3, so that the resistance during degassing can be minimized. As a result, unlike the conventional problem, the valve body sheets 31 are lightly heat-sealed by the heat during heat sealing and the pressure of the metal mold for heat sealing, and even when the forward air flow F1 is passed through the ventilation passage 3, no extra force is required to remove this light heat seal. Therefore, in the present invention, when the sealed part 2 is pressed by hand to degas the air present in the sealed part 2 to the outside of the compression bag 1, even if a person with relatively weak strength such as a child or an elderly person uses it, it is possible to degas lightly with almost no resistance. In addition, the sealed part 2 cannot burst.

[0027] In addition, the valve body sheet 31 may have a separation surface 31d, which is opposite to the contact surface 31a, that has a property of being less adhesive than the contact surface 31a, so that the valve body sheet 31 can be easily lifted up from the bag sheets 11, 12 to which the valve body sheet 31 is attached and from the spacing member 32 described later. Specifically, of the multiple resin films constituting the valve body sheet 31, the resin film constituting the separation surface 31d may be made of a material having poorer adhesiveness than the other resin films, or as shown in Fig. 4(A), the separation surface 31d may be given a matte finish to form unevenness, or as shown in Fig. 4(B), paint 7 may be applied to the separation surface 31d to improve peelability. On the other hand, it is desirable that the contact surface 31a has a property of being easily adhered to the air passage 3, in order to effectively close the air passage 3. For example, among the multiple resin films constituting the valve body sheet 31, the resin film constituting the contact surface 31a may be made of a material having better adhesion than other resin films, i.e., a material having good blocking properties, or an inert liquid 5 such as silicon oil may be arranged on the contact surface 31a in an amount that does not inhibit degassing, as shown in Fig. 5(A)(B), to facilitate adhesion between the valve body sheets 31 and effectively prevent backflow of air in the air passage 3. In the example shown in Fig. 5(A)(B), the valve body sheets 31 closer to the sealed portion 2 than the inert liquid 5 are heat-sealed to form a liquid-stopping seal 6, as shown in Fig. 5(A), so that the inert liquid 5 does not flow to the sealed portion 2 and contaminate the stored article M.

[0028] In addition to the valve sheet 31, the ventilation passage 3 is provided with a spacing member 32 so as to overlap at least a part of the valve sheet 31. In this embodiment, the spacing member 32 is a sheet-like body arranged so as to overlap the valve sheet 31 below the valve sheet 31 shown in FIG. 1(A), specifically, on the tip side of the adhesive part 31b of the valve sheet 31. The tip of the spacing member 32 is arranged at a position on the tip side of 1 / 2, more preferably 3 / 4, of the movable part 31c in the direction from the tip of the valve sheet 31 (the lower side in FIG. 1(A)) to the base end (the upper side in FIG. 1(A)). The spacing member 32 in this embodiment is provided within a range of 30 mm from the lower end side of the compression bag 1 toward the sealed part 2, and its tip coincides with the tip of the valve sheet 31, but the present invention is not limited to this, and the spacing member 32 may be arranged to be shifted from the tip of the valve sheet 31.

[0029] In the air passage 3, the spacing member 32 is bonded to the bag sheets 11, 12 and the valve sheet 31 only at the position of the air passage side seal 33, as shown in Figures 2(A) to (C). Therefore, the spacing member 32 is not bonded anywhere other than the air passage side seal 33 of the air passage 3, and is simply sandwiched between the front bag sheet 11 or the rear bag sheet 12 and the valve sheet 31, and when degassing the sealed portion 2, the air flow passing space 3a is opened as shown in Figures 1(B) and 2(A) so that the forward air flow F1 from the sealed portion 2 to the outside of the compression bag 1 can pass without resistance. Then, after degassing is completed, the valve sheets 31 are in close contact with each other as shown in Figure 2(B). However, as described above, the spacing member 32 is in a free state except at the air passage side seal 33, so that the valve body sheet 31 and the spacing member 32 may remain in contact with each other as shown in Figure 2 (C), and the area between the bag sheets 11, 12 and the spacing member 32 may become the dead end portion 3b described above.

[0030] The spacing member 32 is a thicker sheet than the front and rear sheets 11, 12 and the valve sheet 31, and in the portion where the spacing member 32 is arranged, a gap can be maintained between the front and rear sheets 11, 12 and the valve sheet 31 by the presence of the spacing member 32 (in this example, the thickness of the spacing member 32). In other words, using one valve sheet 31 as a reference, the gap between the other valve sheet 31 and the other valve sheet 31 or the front and rear sheets 11, 12 with which the one valve sheet 31 is in close contact can be narrowed by the thickness of the spacing member 32. Therefore, the valve sheet 31 can more easily close the ventilation passage 3, which effectively prevents backflow of air in the ventilation passage 3, and the deaerated state of the sealed portion 2 can be maintained for a long period of time. In order to reduce the resistance when air is introduced to the dead-end portion 3b formed between the front bag sheet 11 or the rear bag sheet 12 and the valve sheet 31, it is desirable to use a breathable sheet-like material as the spacing member 32, and examples of such materials include a nonwoven fabric, a mesh material, and a woven fabric made of thermoplastic resin fibers that have heat sealability. When the sheets 11, 12, 31, and 32 are bonded together with an adhesive or the like, a material that does not have heat sealability, such as paper, can also be used. In some cases, a sheet made of a resin that does not have breathability, similar to the front bag sheet 11, the rear bag sheet 12, and the valve sheet 31, may be used.

[0031] Also, the spacing member 32 may be made of a filament, as shown in Figures 9(A) to 9(C) and 10. In this case, it is preferable to use a filament made of a thermoplastic resin fiber such as a polyester resin fiber having heat-sealing properties for the spacing member 32, but it is also possible to use a filament made of a natural fiber such as cotton that does not have heat-sealing properties. Here, it is appropriate that the filament in the present invention is implemented as a long body in which the value obtained by dividing the longitudinal dimension by the transverse dimension in the cross-sectional shape is 1 or more and 2 or less. Incidentally, the filament used as the spacing member 32 shown in Figs. 9 and 10 is a general thread, and the cross-sectional shape is a nearly perfect circle. Therefore, the above value is 1. When a filament is used as the spacing member 32, it may be arranged so that the longitudinal direction of the cross-sectional shape is perpendicular to the bag sheets 11, 12 and the valve body sheet 31, or may be arranged so that the transverse direction of the cross-sectional shape is perpendicular to the bag sheets 11, 12 and the valve body sheet 31, and the positional relationship between the cross-sectional shape of the spacing member 32 and each sheet 11, 12, 31 is not limited. 9(B), the front spacing members 32x attached to the front bag sheet 11 and the rear spacing members 32y attached to the rear bag sheet 12 are arranged alternately on the upstream side and the downstream side with respect to the forward airflow F1. As a result, at the respective positions where the spacing members 32 are provided, a spacing corresponding to the spacing members 32 can be maintained at least in a part between the inner surfaces 11a, 12a of the bag sheets 11, 12 and the separating surface 31d of the valve body sheet 31, and the contact surface 31a of the valve body sheet 31 can be protruded into the airflow passing space 3a, thereby curving the airflow air space 3a, thereby enhancing the non-return effect against the reverse airflow F2. To add to the above, Fig. 9(C) shows the valve disc sheet 31 in a straight and tightly attached state for the sake of illustration consistency with Fig. 1(C), but in reality, as shown in Fig. 10, the bag sheets 11, 12 are brought as close as possible, so that the tightly attached valve disc sheet 31 is also curved by the spacing members 32x, 32y arranged in a staggered manner. This curvature of the valve disc sheet 31 can further enhance the check effect against the reverse airflow F2. Incidentally, even when a sheet-like body is used as the spacing maintaining member 32, the front surface side spacing maintaining members 32x and the rear surface side spacing maintaining members 32y may be arranged in a staggered manner.

[0032] By forming the spacing member 32 into a filament-like body as described above, it is possible to reduce the dimension in the direction along the airflow of the movable part 31c of the valve sheet 31, which is the part that comes into contact with the spacing member 32, and thus it is possible to reduce the width dimension (the vertical dimension shown in Fig. 1(A) and Fig. 3) of the entire valve sheet 31. Furthermore, unlike the case where the spacing member 32 is in the form of a sheet, in the production of the compression bag 1, until the step (step [2] described below) in which the spacing member 32 is superimposed on each of the front bag sheet 11 and the rear bag sheet 12 and the valve sheet 31 is further superimposed thereon, it is not necessary to supply the long spacing member 32 parallel to the longitudinal direction to each of the front bag sheet 11, the rear bag sheet 12 and the valve sheet 31, but it can be freely supplied from an oblique direction or a perpendicular direction by folding, etc., which is advantageous in terms of the layout of the production apparatus. In the example shown in Figure 9, one filament-shaped spacing member 32 is arranged on the front bag sheet 11 and one on the rear bag sheet 12, but this is not limited to this, and two or more filament-shaped spacing members 32 may be arranged on the front bag sheet 11 or the rear bag sheet 12.

[0033] Also, the spacing member 32 may be made of a material that exerts a biasing force in a direction to widen the gap between the inner surfaces 11a, 12a of the bag sheets 11, 12 and the receding surface 31d of the valve body sheet 31. Specifically, when the spacing member 32 is a sheet-like body, a sheet made of urethane foam that exerts a repulsive force in the thickness direction can be used. When a sheet made of urethane foam is used in this way, the thickness of the spacing member 32 when applied to the sealing bag 1 is desirably 0.5 mm to 3 mm. By making the spacing member 32 exert a biasing force in this manner, the contact surfaces 31a of the valve body sheets 31 can be brought into closer contact with each other more reliably, thereby closing the airflow passing space 3a and preventing backflow of air.

[0034] Also, the spacing member 32 may be a folded sheet-like member, as shown in Fig. 14(B), and may be divided into a plurality of sections with the fold 32c as a boundary. The one shown in Fig. 14 is folded in two, and as shown in Fig. 14(A), with the fold as a boundary, one section 32a abuts against the inner surfaces 11a, 12a of the bag sheets 11, 12, and the other section 32b abuts against the receding surface 31d of the valve body sheet 31, and both sections 32a, 32b try to spread in opposite directions with the fold 32c as a boundary (shown by the arrows), thereby exerting a biasing force.

[0035] In the above, the bag sheets 11, 12 and the valve sheet 31 are described as separate sheets, but the present invention is not limited to this, and the front bag sheet 11 and the valve sheet 31, and the rear bag sheet 12 and the valve sheet 31 may be integrated. In other words, a portion of the configuration of at least one of the bag sheets 11, 12 may be used as the valve sheet 31.

[0036] Here, the bag sheets 11, 12 are formed by bonding and laminating a plurality of resin films such as polyethylene films and nylon films, but as shown in Fig. 7(A), in the outer resin films 11a, 12a and the inner resin films 11b, 12b constituting the bag sheets 11, 12, adhesive is applied to the adhesive portions 11c, 12c, and the non-adhesive portions 11d, 12d which are the ends of the bag sheets 11, 12 are overlapped without adhesive being applied, so that the outer resin films 11a, 12a and the inner resin films 11b, 12b are separated only at the non-adhesive portions 11d, 12d, as shown in Fig. 7(B). The non-adhesive portions 11d, 12d are used as the ventilation passages 3 of the compression bag 1. That is, as shown in Fig. 6(A), when the outer resin films 11a, 12a are positioned on the outside of the compression bag 1, the outer resin films 11a, 12a are used as equivalent to the front bag sheet 11 shown in Fig. 1(B), and the inner resin films 11b, 12b are used as equivalent to the valve body sheet 31 shown in Fig. 1(B), more specifically, the movable part 31c of the valve body sheet. The spacing member 32 is disposed between the outer resin films 11a, 12a and the inner resin films 11b, 12b. Even when the front bag sheet 11 or the rear bag sheet 12 is made of three or more layers of resin film, the resin film (layer) existing on the outside can be used as equivalent to the front bag sheet 11 shown in Fig. 1(B), and the resin film (layer) existing on the inside can be used as equivalent to the valve body sheet 31 shown in Fig. 1(B), in the same manner as the resin film consisting of two layers. For adhesion of the resin film, various processing methods can be selected, such as wet lamination, extrusion coating lamination, dry lamination, and non-solvent lamination.

[0037] In this example, the valve body sheet 31 is made of two flat sheets, each of which is attached to the front bag sheet 11 and the rear bag sheet 12, but the valve body sheet 31 may also be used in a folded shape, for example, as shown in Figure 6 (B). Also, as shown in Fig. 8, one valve sheet 31 may be used per compression bag and attached only to the front bag sheet 11 or the rear bag sheet 12. In this case, the contact surface 31a of the valve sheet 31 comes into contact with the inner surface 11a of the front bag sheet 11 or the inner surface 12a of the rear bag sheet 12, which faces the contact surface 31a. The valve sheet 31 in the illustrated case is movable within a range from a state in which the airflow passing space 3a is opened and the forward airflow F1 can pass therethrough, as shown in Fig. 8(A), to a state in which the airflow passing space 3a is closed, as shown in Fig. 8(B).

[0038] In this embodiment, the sealed portion 2 is disposed on the upper side and the air passage forming portion 30 is disposed on the lower side with respect to the sealed portion partition seal 14 as shown in Fig. 1, but the configuration is not limited to this. For example, as shown in Fig. 11, the valve body sheet 31 and the spacing member 32 may be disposed vertically on the right end side in the figure, the sealed portion 2 may be the portion on the left side of the sealed portion partition seal 14, which is defined by the sealed portion partition seal 14 extending in the vertical direction in the figure, the bag side seal 16 defining the right end of the sealed bag 1 in the figure, and the bottom seal 15 defining the lower end of the sealed bag 1, and the air passage 3 may be the portion on the right side defined by the sealed portion partition seal 14, which is further defined by the above-mentioned air passage side seal 33, similar to the compression bag 1 shown in Fig. 1, and the bag side seal 16 may be formed at the left end of the sealed bag in the figure, and the opening 1a may be provided at the upper end in the figure. In other words, in the sealed bag (compressed bag) 1 shown in FIG. 1(A), the opening 1a is moved from the upper end to the right end in the figure.

[0039] Also, as shown in Fig. 12, the air passage 3 may be provided at only one location per sealed bag 1. In particular, in this example, the sealed portion 2 and the air passage forming portion 30 are not partitioned as shown in Fig. 1. That is, in this example, the sealed portion partition seal 14 only connects the upper end of the air passage side seal 33 on the right side of the figure to the bag side seal 16 on the right side of the figure, and the sealed portion partition seal 14 is not provided between the air passage side seal 33 on the left side of the figure and the bag side seal 16 on the left side of the figure, and only the bottom seal 15 that defines the lower end of the sealed bag 1 is provided. As a result, even in the portion 2a on the left side of the air passage 3, the opposing valve body sheets 31 remain separated from each other, and this portion 2a can be used as a part of the sealed portion 2 and can be effectively used to store the article M up to the lower end of the sealed bag 1. In addition, even if two air vent passages 3 are provided per sealed bag 1, the sealed portion partition seal 14 between each air vent passage 3 may be omitted, and the sealed portion 2 may be enlarged as described above so that the sealed portion 2 can be used up to the bottom end of the sealed bag 1. When the air passages 3 are arranged at both the left and right ends of the sealed bag 1 as in the above example, the air passage side seals 33 may also serve as the bag side seals 16 .

[0040] 13A, a front inner valve element sheet 31x' having a smaller vertical dimension than the front valve element sheet 31x may be disposed closer to the airflow passage space 3a than the front valve element sheet 31x. With this configuration, the front valve element sheet 31x and the rear valve element sheet 31y are in close contact with each other, and the front inner valve element sheet 31x' and the rear valve element sheet 31y are in close contact with each other. Since the air passage 3 can be closed in two ways in this way, the check effect can be further improved compared to the above-described configuration in which the valve element sheet 31 is composed only of the front valve element sheet 31x and the rear valve element sheet 31y. Furthermore, a rear inner valve body sheet 31y' having a smaller vertical dimension than the rear valve body sheet 31y and the front inner valve body sheet 31x' may be arranged closer to the air flow passage space 3a than the rear valve body sheet 31y, thereby making it possible to close the air passage 3 in three places. Furthermore, as long as the positions at which each sheet is in close contact are shifted in the direction of the air flow in the air passage 3, sheets having the same or larger vertical dimensions than the front side valve body sheet 31x and the rear side valve body sheet 31y may be used as the front inner valve body sheet 31x' and the rear inner valve body sheet 31y'. In addition to the above, the shape of the sealing bag 1 can be modified in various ways.

[0041] Next, a manufacturing method will be described using the compression bag 1 shown in Fig. 1 as an example. In manufacturing the compression bag 1 of this example, the bag sheets 11, 12, the valve body sheet 31, and the spacing member 32 are made of flexible sheets that are continuous in the longitudinal direction without any breaks, and as shown by the arrows in Fig. 15, they are continuously fed to each process described below, where they are successively processed, such as heat sealing and cutting. Note that the same processing can be used even when manufacturing a sealed bag 1 using a filament as the spacing member 32, as shown in Fig. 9.

[0042] First, the closure member 4 is attached by heat sealing to the upper end portion of each of the front bag sheet 11 and the rear bag sheet 12, which will become the opening 1a of the compression bag 1 after completion (step [1]). In this example, the closure member 4 is a zipper having a convex portion on one side of the bag sheets 11, 12 and a concave portion on the other side, and is supplied to each process continuously and without interruption in the longitudinal direction, just like the above-mentioned sheets 11, 12, 31 and spacing member 32.

[0043] At the same time as the closure member 4 is attached, the spacing members 32 are placed on the front bag sheet 11 and the rear bag sheet 12, respectively, and the valve body sheet 31 is placed on top of them (step [2]). The valve body sheet 31 is then bonded to the overlapped front bag sheet 11 or rear bag sheet 12 by applying a valve body adhesive seal S1 by heat sealing (step [3]). The part of the valve body sheet 31 where the valve body adhesive seal S1 is applied is the adhesive part 31b shown in FIG. 1. In the above state, the spacing member 32 is merely sandwiched between the front bag sheet 11 or the rear bag sheet 12 and the valve sheet 31, and has not yet been bonded. Also, in this state, the front bag sheet 11 and the rear bag sheet 12 are separated from each other, so that the valve sheet 31 bonded to the front bag sheet 11 and the valve sheet 31 bonded to the rear bag sheet 12 are not affected by the heat of the heat seal and the pressure of the mold used to perform the heat seal.

[0044] Next, as described above, the front bag sheet 11 and the rear bag sheet 12, each having the valve body sheet 31 bonded thereto and the spacing member 32 overlapped thereon, are overlapped so that the valve body sheets 31 face each other. In other words, the sheets are overlapped so that the valve body sheets 31 and the spacing member 32 are on the inside. Then, the center seal S2 and the bag side seal S3 (16) are formed and adhered to each of the overlapped sheets 11, 12, 31, 32 collectively (step [4]). The center seal S2 is located in the center near the valve seat 31 when the compression bag 1 is completed, and is formed in the longitudinal direction (left-right direction in the figure). In this example, three rows are formed in a line in the vertical direction in the figure. The upper center seal S2a is for straightening the forward air flow F1 and reinforcing the front bag sheet 11 and the rear bag sheet 12, and constitutes the part of the reinforcing seal 13 shown in FIG. 1(A) that is sandwiched between the two air passages 3. The middle center seal S2b is for dividing the sealed part 2 and the air passage 3, and constitutes the part of the sealed part dividing seal 14 shown in FIG. 1(A) that is sandwiched between the two air passages 3. The lower center seal S2c is for defining the lower end of the compression bag 1 and for bonding the sheets 11, 12, 31, and 32 together, and constitutes the part of the bottom seal 15 shown in FIG. 1(A) that is sandwiched between the two air passages 3. The bag side seals S3 (16) define both left and right ends of the compression bag 1 (both longitudinal ends based on the sheets 11, 12, 31, and 32) and serve to bond the sheets 11, 12, 31, and 32 together.

[0045] Next, left and right seals S4 are formed on the left and right sides of the center seal S2 formed as described above (step [5]). The left and right seals S4 are composed of a left and right seal S41 and a top and bottom seal S42. The left and right seals S41 are formed in the longitudinal direction (left and right direction in the figure) in this example, and are formed in three rows in the top and bottom direction in the figure, and have the same function as the center seal S2. That is, the upper left and right seal S41a is for straightening the forward air flow F1 and reinforcing the front bag sheet 11 and the rear bag sheet 12, and constitutes the end part of the bag from the two air passages 3 of the reinforcing seal 13 shown in FIG. 1(A). The middle left and right seal S41b is for dividing the sealed part 2 and the air passage 3, and constitutes the end part of the bag from the two air passages 3 of the sealed part dividing seal 14 shown in FIG. 1(A). The lower left-right seal S41c defines the lower end of the compression bag 1 and is for bonding the sheets 11, 12, 31, and 32 together, and constitutes the end side portion of the bag from the two air passages 3 among the bottom seals 15 shown in FIG. 1(A). The vertical seal S42 is the air passage side seal 33 already described, and is a seal located on both the left and right sides of the air passage 3 as shown in FIG. 1(A) when the compression bag 1 is completed, and formed in the vertical direction in the figure. Therefore, the left and right sides of the air passage 3 are defined by this vertical seal S42. The upper end of the air passage 3 is defined by the position on the extension line of the intermediate center seal S2b and the intermediate left-right seal S41b of the left and right side seals S4. In other words, the upper end of the vertical seal S42, which is closer to the sealed portion 2, is formed continuously with the intermediate center seal S2b and the intermediate left-right seal S41b, which become the sealed portion partition seal 14. In this embodiment, the position of the upper end of the ventilation passage 3 coincides with the upper end of the valve sheet 31 and the valve adhesive seal S1, but it may be formed to be shifted, and various modifications can be made. Also, the lower end of the ventilation passage 3 is defined by the lower ends of the bag sheets 11 and 12 in this embodiment.

[0046] The above-described seals S1 to S4 are formed by pressing a heated metal mold against each of the sheets 11, 12, 31, and 32. Since the seals S1 to S4 are formed in the above-described procedure, the metal mold is not pressed against each of the sheets 11, 12, 31, and 32 at the portion of the air passage 3 corresponding to the position where the air flow passes, and no heat sealing is performed at all. Therefore, unlike the conventional method, the valve body sheets 31 are lightly bonded together by the heat during heat sealing and the pressure of the metal mold for heat sealing, and the air passage 3 is closed. Therefore, when the sealed portion 2 of the completed compression bag 1 is pressed by hand to evacuate the air present in the sealed portion 2 to the outside of the compression bag 1, even when used by a person with relatively weak strength such as a child or an elderly person, there is almost no resistance and the air can be easily evacuated. As described above, the valve body adhesive seal S1 is applied separately in advance between the front bag sheet 11 and the valve body sheet 31, and between the rear bag sheet 12 and the valve body sheet 31. Moreover, since the front bag sheet 11 and the rear bag sheet 12 are separated at this time, the heat applied when the valve body adhesive seal S1 is formed by heat sealing and the pressure of the mold used to apply the heat seal do not have any adverse effect on the formation of the air passage 3.

[0047] Finally, the sheets 11, 12, 31, 32 and the closure means 4 are cut in the vertical direction in the figure so as to equally divide the bag side seal S3 (16), thereby completing the compression bag 1 (step [6]). In the manufacturing method of the compression bag 1 according to the present invention, sheets 11, 12, 31, 32 that are continuous without interruption in the longitudinal direction and closing means 4 are continuously supplied to each process ([1] to [6]), and compression bags 1 are formed one after another by sequential processing such as heat sealing and cutting. Therefore, there is no need for the complicated manufacturing process of manufacturing check valve 105 separately from the sheet that constitutes sealing portion 102 as in the conventional example shown in Figure 16 and later incorporating it when forming sealing portion 102. Therefore, manufacturing is relatively easy and manufacturing costs can be reduced.

Claims

[Claim 1] The sealing portion (2) is provided with an air passage (3) capable of sealing the sealing portion (2) in an airtight state; The structure of the ventilation path (3) is such that it connects the sealed portion (2) to the outside of the bag in a breathable manner in order to exhaust gas present in the sealed portion (2) to the outside of the bag and maintain that state, or to fill the sealed portion (2) with gas and maintain that state, In the above-mentioned exhaust or filling of the gas, an air flow passage space (3a) through which the gas passes can be opened and closed to allow the passage of the air flow in one direction and block the air flow in the other direction, Flexible resin bag sheets (11, 12) arranged opposite to each other; At least one valve body sheet (31) made of flexible resin, which is disposed between the bag sheets (11, 12), a part of which is bonded to at least one of the bag sheets (11, 12) at a bonding part (31b), and a movable part (31c) other than the bonding part (31b) is made movable; The valve body sheet (31) is bonded to the bag sheet (11, 12) as described above, and a spacing member (32) is disposed between the bag sheet (11, 12) and the valve body sheet (31), The spacing member (32) is one selected from a filament, a nonwoven fabric, a mesh, a woven fabric, paper, and a resin sheet having no air permeability; The air passage (3) is defined by a pair of air passage side seals (33) formed by bonding the bag sheets (11, 12), the valve body sheet (31), and the spacing member (32) together, and one end of the air passage (3) is connected to the sealed portion (2) and the other end is connected to the outside of the bag. The air passage side seal (33) is formed along the forward air flow (F1), which is the direction in which gas is allowed to pass through the air passage; the adhesive portion (31b) of the valve body sheet (31) is disposed on the upstream side of the forward airflow (F1), and the movable portion (31c) is disposed on the downstream side of the forward airflow (F1); In the movable portion (31c), a surface facing the inner surface (11a, 12a) of the bag sheet (11, 12) to which the valve body sheet (31) to which the movable portion (31c) belongs is bonded is a separation surface (31d), and a surface opposite to the separation surface (31d) is a contact surface (31a), the spacing member (32) is disposed between the inner surface (11a, 12a) of the bag sheet (11, 12) and the facing surface (31d) of the valve body sheet (31), thereby enabling a spacing of the spacing member (32) to be maintained at least in a portion between the inner surface (11a, 12a) of the bag sheet (11, 12) and the facing surface (31d) of the valve body sheet (31); With respect to the forward airflow (F1), the valve body sheet (31) is separated from the bag sheet (11, 12) or the valve body sheet (31) on the other side, which faces the contact surface (31a) of the valve body sheet (31), and the airflow passage space (3a) is opened. The sealed bag is characterized in that, for a reverse air flow (F2) which is opposite to the forward direction, the valve body sheet (31) and the bag sheet (11, 12) or the valve body sheet (31) on the other side opposite to the contact surface (31a) of the valve body sheet (31) are tightly contacted with each other, thereby closing the air flow passage space (3a).

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