JP5624855B2 - Bag body, laminated body, and manufacturing method of bag body - Google Patents

Description

  The present invention relates to a bag body, a laminate used for the bag body, and a method for manufacturing the bag body.

  Conventionally, for bags containing ice confectionery, etc., it has been required to improve heat insulation because it feels cold when a customer grips it by hand, and in recent years a laminated body that has been provided with a foamed resin layer to improve heat insulation For example, in the bag body described in Patent Document 1, foamed polyethylene (foaming ratio: 35 times) having a thickness of 500 μm is used as the foamed resin layer of the laminate.

JP 2001-130586 A

However, since the above-mentioned foamed resin layer is fragile to the force in the peeling direction and the shearing direction, when the laminates are bonded to each other by heat sealing to form a bag body using the laminate having the foamed resin layer, heat sealing There is a problem that stress due to internal pressure concentrates in the vicinity of the portion, and sufficient bag drop strength and compressive strength may not be obtained.
For example, when the sealant layer on the inner surface side of the foamed resin layer is stretched and torn, the foamed resin layer is also stressed and broken, and at that time, the foamed resin layer breaks continuously from the broken part. There is a risk that the contents leak.
Moreover, by forming the sealant layer on the inner surface side of the foamed resin layer thicker, it is possible to prevent the sealant layer from being broken and to improve the compressive strength in the vicinity of the seal part of the bag body. However, there is a problem that the cost increases by the amount formed.

  The present invention has been made in view of the above circumstances, and a bag body, a laminate, and a bag body that can prevent the occurrence of leakage by using a foamed resin layer and can suppress an increase in cost. The manufacturing method of this is provided.

  In order to solve the above-described problems, the invention described in claim 1 is a bag formed by heat-sealing a peripheral portion of a film-like laminate including at least a foamed resin layer, wherein the laminate is heat-sealed. A solid portion formed by crushing the foamed resin layer is disposed in an inner region in the vicinity of the heat seal portion.

  The invention described in claim 2 is characterized in that, in the invention described in claim 1, the solid part is arranged in an inner region in the vicinity of the intersection of the gusset fold line and the heat seal part.

  The invention described in claim 3 is characterized in that, in the invention described in claim 1 or 2, the solid part is arranged in an inner region in the vicinity of the plug attaching part to which the plug is attached.

  A fourth aspect of the present invention is a laminated body for forming the bag according to any one of the first to third aspects, wherein a solid portion is formed at least in part.

  Invention of Claim 5 is a manufacturing method of the bag body as described in any one of Claim 1 thru | or 3, Comprising: The process which forms a solid part previously in a laminated body, and heat-sealing this laminated body And a step of forming the bag body.

  According to the bag of the present invention, the sealant layer is apparently provided by crushing the foamed resin layer in the inner region in the vicinity of the heat seal portion where the stress is easily applied when the internal pressure is increased to form a solid portion. For example, the compressive strength in the vicinity of the heat seal portion can be increased without providing a thick sealant layer on the inner surface side of the foamed resin layer. Therefore, there is an effect that the occurrence of leak can be prevented by improving the compressive strength and the cost increase can be suppressed.

Furthermore, according to the laminated body of the present invention, since the foamed resin layer is solidified by previously forming the solid portion, there is an effect that the compressive strength of the bag body using the same can be improved. .
Furthermore, according to the manufacturing method of the bag body of the present invention, when the solid portion is formed by forming the solid portion in the laminated body in advance and then forming the heat seal portion bonded by heat sealing. Since it is possible to prevent sticking between the inner surfaces of the laminated body other than the heat seal part, complicated work is not necessary when forming the solid part, and a bag body with improved compression strength can be easily manufactured. effective.

It is a front view of the three-way bag which is a bag body in 1st Embodiment of this invention. It is a front view of the 4-way bag which is a bag body in 1st Embodiment of this invention. It is sectional drawing of the heat seal part vicinity of the bag body in 1st Embodiment of this invention. It is a figure which shows the laminated body before bag making in 1st Embodiment of this invention. It is a front view of the 3-way bag which is a bag body of the modification in 1st Embodiment of this invention. It is a perspective view of the bag in a 2nd embodiment of the present invention. It is a front view of the bag body in 2nd Embodiment of this invention, and is a figure of the state by which the upper part was open | released. It is a front view of the bag body in 2nd Embodiment of this invention, and is a figure of the state by which the upper part was obstruct | occluded. It is a perspective view of the bag body of the 1st modification in 2nd Embodiment of this invention. It is a front view of the bag body of the 1st modification in 2nd Embodiment of this invention. It is a perspective view of the bag in a 3rd embodiment of the present invention. It is sectional drawing of the heat seal part vicinity in 3rd Embodiment of this invention, Comprising: (a) is sectional drawing which follows an AA line, (b) is sectional drawing which follows an A'-A 'line. It is a front view of the bag in a 3rd embodiment of the present invention. It is sectional drawing which follows the BB line of FIG. It is a perspective view of the bag body of the 2nd modification in 2nd Embodiment of this invention. It is a front view of the bag body of the 2nd modification in 2nd Embodiment of this invention.

Next, the bag body of 1st Embodiment of this invention is demonstrated, referring drawings.
Drawing 1 is a figure which looked at bag body 1 of this embodiment from the front. This bag 1 is formed by stacking the inner surfaces of a laminate 5a arranged on the front side and a laminate 5b (not shown) arranged on the back side, and heat-sealing the peripheral portion. This is a so-called flat pouch. This bag 1 shows a state before filling the contents, and an opening 2 is formed in the upper part, and has a symmetrical shape. In addition, since the laminated body 5a and the laminated body 5b are the same structures, only the laminated body 5a is demonstrated except the especially required case, and description of the laminated body 5b is abbreviate | omitted.

  The bag body 1 is formed with heat seal portions 7a to 7c along the left edge portion, the right edge portion, and the lower edge portion, respectively, and more specifically in the vicinity of the heat seal portions 7a to 7c. The solid portions 30a to 30c having a predetermined width (for example, about 0.5 to 20 mm width described above) are formed in the inner region adjacent to the heat seal portions 7a to 7c. These solid portions 30a to 30c are formed by melt pressurization in the same manner as the heat seal portions 7a to 7c. After the bag 1 is filled with the contents, the opening 2 is closed, but also in the inner region adjacent to the heat seal portion 7d (see FIG. 2) bonded by heat sealing at the time of closing, A solid portion 30d is formed in advance along the inner edge of the heat seal portion 7d. The solid portion 30d is formed to have a predetermined width (for example, about 0.5 to 20 mm) in the same manner as the solid portions 30a to 30c described above. And as shown in FIG. 2, if the opening part 2 of the bag body 1 is obstruct | occluded by heat seal, the bag body 1 will become a 4-way seal bag.

FIG. 3 shows the vicinity of the heat seal portion 7 in which the edge 6a of the laminate 5a on the front surface and the edge 6b of the laminate 5b on the back surface are bonded by heat sealing.
The laminated body 5 a and the laminated body 5 b are formed by laminating the base material layer 10, the functional layer 11, the foamed resin layer 12, and the sealant layer 13 in order from the outside in the inner and outer directions of the bag body 1. The foamed resin layer 12 and the sealant layer 13 are laminated by a coextrusion method or the like. And what laminated | stacked the foamed resin layer 12 and the sealant layer 13, the base material layer 10, and the functional layer 11 are adhere | attached and laminated | stacked by the dry lamination method etc. FIG. In addition, as a lamination | stacking method of the laminated bodies 5a and 5b, a dry lamination method, an extrusion lamination method, a non-solvent lamination method, etc. are mentioned, However, It is preferable to use the dry lamination method in terms of adhesive strength.

  The base material layer 10 has the strength of the laminated body 5a and becomes the outermost layer when molded into the bag body 1, and is made of polyethylene terephthalate (polyester), polyamide (nylon), polypropylene, polyvinyl alcohol, ethylene-vinyl. It is formed of a film made of a synthetic resin such as an alcohol copolymer, polycarbonate, and polyacetal, or a film obtained by co-extruding these synthetic resins. These films may be unstretched films or stretched films stretched in a uniaxial direction or a biaxial direction. Moreover, it is preferable that the film used for the base material layer 10 uses the stretched film extended | stretched to the uniaxial direction or the biaxial direction from a printing appropriate viewpoint. Moreover, the thickness of the base material layer 10 is 6 micrometers-50 micrometers, More preferably, they are 9 micrometers-25 micrometers.

  The functional layer 11 has various functions such as providing gas barrier properties and mechanical strength such as tensile strength, and is formed of a metal foil or various plastic films. Examples of the metal constituting the metal foil include aluminum, iron, copper, and magnesium. The plastic film may be polyethylene, polypropylene, polyethylene terephthalate (polyester), polyamide (nylon), polyvinyl chloride, polycarbonate, polyacrylonitrile, polyvinyl alcohol, ethylene-vinyl copolymer, or the like. A resin coated with a gas barrier resin such as vinylidene, or various vapor deposited films obtained by depositing an inorganic substance such as aluminum, silicon oxide, aluminum oxide, magnesium oxide on these plastic films can be used. The thickness of the functional layer 11 is 6 μm to 50 μm, more preferably 6 μm to 25 μm. Note that a plurality of functional layers 11 may be provided.

  The foamed resin layer 12 has a function of enhancing the heat insulating property of the laminate 5a, and each of the foamed polyethylenes such as polyurethane, low density polyethylene, linear low density polyethylene, medium density polyethylene, and high density polyethylene is used. And polypropylenes such as homopolypropylene, random polypropylene and block polypropylene, and copolymer resins such as ethylene-vinyl acetate copolymer and ethylene-propylene copolymer. Among these, polyethylenes are particularly preferable, and among the polyethylenes, low density polyethylene is preferable because it easily forms a solid with a low melting point. The thickness of the foamed resin layer 12 is 70 μm to 250 μm, more preferably 100 μm to 200 μm. As a foaming means for the foamed resin layer 12, chemical foaming that generates nitrogen gas or carbon dioxide gas with azodicarbonamide, sodium hydrogen carbonate or the like, or physical foaming using a gas such as carbon dioxide gas (carbon dioxide gas) or nitrogen gas. Law. The physical foaming method also includes foaming means using a fluid in a subcritical state or a supercritical state. Among these foaming means, as a foaming means suitable for food use from the viewpoint of safety, a physical foaming method using carbon dioxide gas and nitrogen gas is preferable, and among them, supercritical carbon dioxide gas or nitrogen gas is used. Especially preferred is the foaming means. The expansion ratio of the foamed resin layer 12 is 1.2 to 3.0 times, and more preferably 1.5 to 2.5 times. The foamed resin layer 12 is preferably open-celled, but may be closed-celled.

  The sealant layer 13 has a function of adhering and fixing the laminates by heat sealing. By providing this sealant layer 13, the sealing strength is improved. Here, examples of the resin used for the sealant layer 13 include polyolefins such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, and polypropylene. Thus, it is preferable to use linear low density polyethylene. The thickness of the sealant layer 13 is 10 μm to 200 μm, more preferably 20 μm to 100 μm.

  Here, the foamed resin layer 12 and the sealant layer 13 described above are preferably laminated mainly by a coextrusion method. However, a dry laminate method in which the layers are laminated through an adhesive or a sealant melted in the foamed resin layer 12 is used. You may laminate | stack using the extrusion laminating method etc. which laminate | stack the layer 13. FIG.

When the edges of the laminated body 5a and the laminated body 5b are bonded together by heat sealing, the bubbles of the foamed resin layer 12 are crushed and changed into a solid form. When the normal thickness of the foamed resin layer 12 is about 100 μm, the thickness of the portion that has changed to a solid is about 50 μm.
Similarly, when the laminated body 5a and the laminated body 5b are melted and pressed to form the solid portions 30a to 30d, the foamed resin layer 12 has a normal thickness of about 100 μm, but the bubbles are crushed. As a result, the thickness is changed to a solid state and is about 50 μm thick.

  That is, when the thickness of the sealant layer 13 is 50 μm, the thickness of the laminated resin layer 12 and the sealant layer 13 is 100 μm in the solid portion and the portion where the solid portions 30a to 30d are formed. It is about. And since the solid part and the solid parts 30a-30d by which the bubble of the foamed resin layer 12 was crushed will be in the substantially same layer state as the sealant layer 13, the thickness of the sealant layer 13 seemed to increase. As a result, the strength in the peeling direction and the shearing direction of the portion where the solid portions 30a to 30d are formed is increased. Note that, when viewed from the inside of the laminates 5a and 5b, that is, from the sealant layer 13 side, the portion of the normal foamed resin layer 12 is visually recognized as white by air bubbles, whereas the solid portion 30 is the foamed resin layer. The 12 bubbles are crushed and the resin is solidified.

Next, the manufacturing method of the bag body 1 in this embodiment will be described.
First, the film-like laminates 5a and 5b constituting the front and back surfaces of the bag body 1 are formed by laminating the base material layer 10, the functional layer 11, the foamed resin layer 12, and the sealant layer 13 in this order.

  Next, as shown in FIG. 4, melt pressure is applied to the inner regions in the vicinity of the locations where the heat seal portions 7 a to 7 d are to be formed on the laminates 5 a and 5 b, and the foamed resin layer 12 is crushed. Solid portions 30a to 30d are formed. The shapes of these solid portions 30a to 30d are appropriately changed according to the shape of bag making. And the laminated bodies 5a and 5b formed in this way are made into roll shape. Here, since the solid portions 30a to 30d of the stacked bodies 5a and 5b are formed in a symmetrical shape, the stacked bodies 5a and 5b can use a common roll. In addition, you may make it perform the process of forming solid part 30a-30d in the process different from the process of making laminated body 5a, 5b into a roll shape, for example, the process of bag making.

  Thereafter, in order to form the bag body 1, roll-shaped laminates 5 a and 5 b are set in a bag making machine (not shown), and the laminates 5 a and 5 b are cut into an appropriate size and a sealer (not shown). 3) to form a bag 1 having an opening 2 by heat-sealing the three sides. Here, when the bag body 1 in the state of the three-side seal bag is separately supplied to a filling sealing machine (not shown) for a flat pouch, the filling of the contents and the sealing of the opening 2 are performed and the four-side seal is performed. After the bag is formed, the date of manufacture and the like are printed.

  Therefore, according to the bag body 1 of 1st Embodiment mentioned above, when the internal pressure of the bag body 1 becomes high, it crushes the foamed resin layer 12 of the inner area | region of the heat seal part 7a-7d vicinity which is easy to apply stress. By forming the solid portions 30a to 30d, the strength in the peeling direction and the shear direction in the vicinity of the heat seal portions 7a to 7d can be increased, and in particular, a three-side sealed bag and a bag body that is a four-side sealed bag The strength can be increased over the entire inner circumference of one heat seal portion 7a to 7d. As a result, even if the foamed resin layer 12 is provided, the strength of the inner circumference of the heat seal portions 7a to 7d can be improved to improve the compressive strength of the bag 1 and the functional layer. The increase in cost due to the increase in the thickness of 11 can be suppressed.

  Moreover, according to the manufacturing method of the bag body 1 of 1st Embodiment, solid part 30a-30d is previously formed in laminated body 5a, 5b, and it adheres by heat seal after that, solid part 30a-30d. When the solid portions 30a to 30d are formed, it is possible to prevent the inner surfaces of the stacked bodies 5a and 5b from sticking to each other, so that no complicated work is required when forming the solid portions 30a to 30d. The bag body 1 with improved compression strength can be easily manufactured.

  In addition, in 1st Embodiment mentioned above, although the case where solid part 30a-30d was formed over the inner circumference of heat seal part 7a-7d was demonstrated, as shown in FIG. You may make it provide only the solid parts 30a and 30b arrange | positioned inside the right and left heat seal parts 7a and 7b. By forming in this way, it is possible to reduce the range in which the solid portion is formed, and to improve the strength at the corners of the heat seal portions 7a to 7d to which stress is particularly easily applied.

Next, a bag body 101 according to a second embodiment of the present invention will be described with reference to the drawings.
The bag body 101 of this embodiment is an optimized arrangement of solid portions in a gusset-type bag body whose left and right side surfaces are folded inward.
As shown in FIG. 6, the bag body 101 is formed by forming a film-like laminate 105 into a cylindrical shape, forming gusset folds 102 on the left and right side surfaces thereof, and closing the lower portion of the laminate 105 by heat sealing. Is done. For example, after the bag body 101 is filled with the contents, the upper opening 108 is closed by heat sealing. In addition, since the laminated body 105 of this embodiment has the same laminated structure as the laminated body 5 of 1st Embodiment mentioned above, detailed description is abbreviate | omitted.

  As shown in FIG. 7, a foamed resin layer is formed in the inner region near the intersection where the inner edge of the gusset fold 102 (shown by a broken line in FIG. 7; gusset fold line) 102a and the lower heat seal 107a intersect. A lower solid portion 130a in which 12 bubbles are crushed is formed. The lower solid portion 130a is formed adjacent to the lower heat seal portion 107a and extends from the longitudinal center of the lower heat seal portion 107a to the left and right outer sides to a position slightly beyond the inner edge 102a of the gusset folding portion 102. It reaches.

  On the other hand, the upper solid portion 130b is formed in a position symmetrical with the lower heat seal portion 107a in the vertical direction, that is, in an inner region in the vicinity of the planned position 110 where the upper heat seal portion 107b is formed. The upper solid part 130b and the lower solid part 130a are formed by melt-pressing the laminated body 105 in advance before the upper heat seal part 107b and the lower heat seal part 107a are formed. Then, as shown in FIG. 8, the upper opening 108 is bonded and closed by heat sealing, so that the upper heat sealing portion 107b and the upper solid portion 130b are disposed adjacent to each other.

  Therefore, according to the third embodiment described above, particularly in the case of the gusset type bag body 101, the inner edge 102a, the upper heat seal portion 107b, and the lower heat seal of the gusset folding portion 102 that are particularly susceptible to stress due to internal pressure. Since the strength of the inner region near the intersection with the portion 107a can be improved by the upper solid portion 130b and the lower solid portion 130a, the compressive strength of the gusset type bag body 101 can be improved efficiently.

  In addition, in 2nd Embodiment mentioned above, although the bag body 101 which has the gusset fold part 102 in the right-and-left side surface was demonstrated to an example, it is not restricted to what has the gusset fold part 102 in the left and right side surface, As FIG. As shown in FIG. 10, the present invention is also applicable to a bottom gusset type bag body 301. In the case of this bottom face gusset type bag body 301, the front edge of the gusset fold portion 302 (the gusset fold line) 302a (shown by a dashed line in FIGS. 9 and 10) and the left heat seal portion in front view A predetermined width (e.g., adjacent to each of the heat seal portions 307a, 307b, and 307c from the inside near the intersection of 307a to the inside of the vicinity of the intersection with the heat seal portion 307b along the heat seal portion 307c on the bottom side. A solid portion 330 (about 0.5 to 20 mm) is formed in the stacked bodies 305a and 305b. According to the configuration of the first modified example, the bottom portion gusset-type bag 301 is formed by forming the solid portion 330 inside the vicinity of the intersection between the inner edge 302a and the heat seal portions 307a and 307b on both the left and right sides. In addition, it is possible to sufficiently improve the compressive strength, and further, the solid portion 330 is formed along the heat seal portion 307c on the bottom side, thereby further improving the body compressive strength of the bag 301. Can be achieved.

Next, a bag body 201 according to a third embodiment of the present invention will be described with reference to the drawings. In addition, since the laminated body 205a and the laminated body 205b of this embodiment have the same laminated structure as the above-described laminated bodies 5a and 5b, detailed description of each layer of the laminated bodies 205a and 205b is given the same reference numerals. Is omitted.
FIG. 11 shows a bag body 201 in this embodiment. The bag body 201 is, for example, a gusset type bag body filled with ice confectionery or the like, and includes gusset folding portions 202 that are folded toward the center in the width direction of the bag body 201 on both left and right side surfaces thereof. Furthermore, a plug 204 is attached to the upper central portion 203 of the bag body 201. In this bag body 201, the inner surfaces of the edge portions 206 a to 206 d adjacent to each other of the four film-like laminates 205 a to 205 d forming a total of four surfaces of the front surface, the back surface, the left surface, and the right surface are bonded together by heat sealing. . Note that the cap 204 is usually mounted by screwing a lid (not shown), and the bag 201 is in a sealed state with the lid mounted. When a load is applied to the bag body 201 from the outside, the internal pressure increases according to the force. For example, when the plug 204 is in an open state, the contents are passed through the plug 204 according to the pressed force. It will be pushed out of the body 201.

FIG. 12A shows the heat seal portion 7 in which the edge portion 206a of the laminated body 205a on the front surface and the edge portion 206b of the laminated body 205b on the back surface are bonded by heat sealing, and the vicinity thereof. And the vicinity has the same structure as FIG. 3 of 1st Embodiment mentioned above.
On the other hand, FIG. 12B shows the heat seal portion 207 where the edge portion 206a of the laminated body 205a on the surface and the edge portion 206c of the laminated body 205c on the left surface are bonded by heat sealing and the vicinity thereof. In addition, the bag body 201 is formed to be a substantially front and back object, and the laminated body 205a on the front surface and the laminated body 205b on the back surface have the same structure, and the laminated body 205c on the left surface and the laminated body 205d on the right surface have the same structure. Therefore, hereinafter, only the heat seal part 207 to which the laminated body 205a and the laminated body 205c are bonded will be described, and description of the other heat seal parts 207 will be omitted.

  The laminated body 205a is formed by laminating the base material layer 10, the functional layer 11, the foamed resin layer 12, and the sealant layer 13 in order from the outside in the inner and outer directions of the bag body 201 by dry lamination or the like. The left side laminate 205c and the right side laminate 205d are formed by laminating the base material layer 20, the functional layer 21, and the sealant layer 23 in order from the outside in the inner and outer directions of the bag body 201 by dry lamination or the like. In addition, the lamination method of the laminated bodies 205a to 205d includes a dry lamination method, an extrusion lamination method, a non-solvent lamination method, and the like, as in the first embodiment, but the dry lamination method is used in terms of adhesive strength. preferable.

  The base material layer 20, the functional layer 21, and the sealant layer 23 of the laminate 205 c that form the side surface of the bag body 201 have the same configuration as the base material layer 10, the functional layer 11, and the sealant layer 13 of the laminate 5 a described above. is there.

  As shown in FIGS. 10 to 14, in addition to the heat seal portion 207, each of the above-described laminates 205 a is formed with a solid portion 230 in which bubbles in the foamed resin layer 12 are crushed by melt-pressing so as to be in a non-foamed state. . The solid portion 230 is sufficiently disposed in an inner region in the vicinity of the heat seal portion 207, more specifically, on the inner side adjacent to the heat seal portion 207 of the plug attachment portion 231 to which the plug 204 on which stress is likely to concentrate is attached. The film is formed to have a width of about 0.5 to 20 mm, more preferably about 10 mm. The solid portion 230 is also formed with a width of about 0.5 to 20 mm, more preferably about 10 m, on the inner side adjacent to the corners of the plug attachment portion 231 and the left and right heat seal portions 207.

  The solid portion 230 is formed by melt pressurization in which pressure is applied while heating, as in the case of forming the heat seal portion 207 described above. Here, when the thickness of the foamed resin layer 12 is about 100 μm, the thickness of the foamed resin layer 12 is reduced to about 50 μm by the collapse of the bubbles. And when it sees from the inner side of laminated body 205a, 205b, ie, the sealant layer 13, the part of the normal foamed resin layer 12 is visually recognized a little white by the bubble, whereas the solid part 230 is a foamed resin layer 12 bubbles are crushed and resin (polyethylene or the like) is solidified.

<Example>
Examples of the present invention and comparative examples will be described below.
In the laminates 205a and 205b of this example, the base material layer 10 was formed of polyethylene terephthalate having a thickness of 12 μm, and the functional layer 11 was formed of aluminum-deposited polyethylene terephthalate having a thickness of 12 μm having an aluminum deposition film on the surface. . In addition, the foamed resin layer 12 was formed of polyethylene having a thickness of 100 μm having broken open cells. Further, the above-described sealant layer 13 was formed of a linear low density polyethylene having a thickness of 50 μm.

In the laminates 205c and 205d, the base material layer 20 was formed of polyethylene terephthalate having a thickness of 12 μm, and the functional layer 21 was formed of aluminum vapor-deposited nylon having an aluminum vapor-deposited film on the surface. A sealant layer 23 having a thickness of 70 μm was formed inside the functional layer 21.
And the solid part 230 about 15 mm wide is formed in the inner area | region adjacent to the heat seal part 207 of the cap attachment part 231, and the edge part of the laminated bodies 205a-205d is heat-sealed, respectively, and a bag of a gusset type The body 201 was molded.
Next, when a test was performed on 10 samples by filling the bag body 201 formed as described above with 140 ml of tap water as the contents and pressurizing with a load of 70 kgf for 1 minute, no leakage occurred.

<Comparative example>
In the laminates 205a and 205b of the comparative examples, the base material layer 10 was formed of polyethylene terephthalate having a thickness of 12 μm, and the functional layer 11 was formed of aluminum-deposited polyethylene terephthalate having a thickness of 12 μm having an aluminum deposition film on the surface. . In addition, the foamed resin layer 12 was formed of polyethylene having a thickness of 100 μm having broken open cells. Further, the above-described sealant layer 13 was formed of a linear low density polyethylene having a thickness of 50 μm.

In the laminates 205c and 205d, the base material layer 20 was formed of polyethylene terephthalate having a thickness of about 12 μm, and the functional layer 21 was formed of aluminum vapor-deposited nylon having an aluminum vapor-deposited film on the surface. Inside this functional layer 21, a sealant layer 23 was formed of linear low density polyethylene having a thickness of 70 μm.
And the edge part of the laminated bodies 205a-205d was heat-sealed, respectively, and the gusset type bag body was shape | molded.

  Next, as in the above-described example, a test was performed on 10 samples by filling a bag with 140 ml of tap water, pressurizing with a load of 70 kgf and holding for 1 minute, and leakage occurred in 7 samples. This is because the inner surface side of the foamed resin layer 12 in the vicinity of the heat seal portion 207 is stretched by pressurization, while the base material layer 20 does not stretch as much as the foamed resin layer 12, so there is a difference in stretch between the front and back of the foamed resin layer 12. As a result, a shear direction load is applied to the foamed resin layer 12. And it is estimated that the inside of the foamed resin layer 12 is broken by the load in the shearing direction, and the tap water leaks to the outside through the broken portion of the foamed resin layer 12. In general, since the sealant layer 13 is easier to extend than the functional layer 11, when the sealant layer 13 is used, stress is applied to the foamed resin layer 12 in the same manner as described above, and the resin layer 12 is broken. In this case, tap water as the contents leaks to the outside through the foamed resin layer 12 when the elongation of the sealant layer 13 exceeds the limit.

  Therefore, according to the bag body 201 of the first embodiment described above, mechanical strength such as tensile strength is sufficiently obtained because the foamed resin layer 12 is crushed and solidified by heat sealing in the heat seal portion 207. In addition, a solid portion 230 is formed by melting and compressing the foamed resin layer 12 in the inner region in the vicinity of the heat seal portion 207 where stress is easily applied when the internal pressure of the bag body 201 is increased. By doing so, the mechanical strength such as the tensile strength in the vicinity of the heat seal portion 207 can be increased without using the thick sealant layer 13, thereby preventing the occurrence of leaks and suppressing the increase in cost. Can do.

  Further, when the plug 204 is bonded to the laminated bodies 205a and 205b at the plug attaching portion 231 by heat sealing, the peeling direction of the laminated bodies 205a and 205b in the vicinity of the heat seal portion 207 of the plug attaching portion 231. In addition, since the strength in the shear direction can be improved, the compression strength of the bag body 201 to which the plug 204 is attached can be improved.

The present invention is not limited to the configuration of each of the above-described embodiments, and the design can be changed without departing from the gist thereof.
For example, in the second embodiment described above, the bag body 101 including the gusset folding part 102 on the left and right and the bag body 301 including the gusset folding part 302 at the bottom as the first modification have been described as an example. The present invention can be applied to a so-called three-way gusset type bag body 401 having gusset folding portions 402c to 402e on the bottom surface and the left and right side surfaces as in the second modification shown in FIGS. In the case of the three-sided gusset type bag 401, the laminated body 405a on the front surface, the laminated body 405b on the back surface, the laminated body 405c constituting the left gusset folding part 402c, and the laminated body constituting the right gusset folding part 402d. The body 405d and the laminated body 405e constituting the bottom gusset folding portion 402e are molded by bonding the inner surfaces thereof by heat sealing at the respective edge portions. Each of these laminates 405a to 405e has a foamed resin layer 12.

  As shown in FIG. 16, the bag body 401 is a front view of the folded state before being filled with the contents, and the inner edge (gazette folding line) 412 e of the bottom gusset folding portion 402 e and the bag body 401. Inner region near the intersection with the peripheral heat seal portion 407, in other words, the inner region adjacent to the heat seal portion 407 at the point P where the inner edge 412e and the heat seal portion 407 of the stacked bodies 405a and 405b intersect. In addition, a solid portion 430 having a predetermined width (for example, about 0.5 to 20 mm) is formed. The solid portion 430 further wraps around the inner region adjacent to the bottom surface side heat seal portion 407 via the corner portion of the bag body 401 and covers the entire inner region adjacent to the bottom surface side heat seal portion 407. Formed. That is, the solid portion 430 is formed along the heat seal portion 407 on the bottom surface side of the stacked bodies 405a and 405b, and extends upward from the both end portions to the point P to exhibit a U-shape. In addition, the code | symbol 412c shows the inner side edge of the gusset folding part 402c, and the code | symbol 412d shows the inner side edge of the gusset folding part 402d.

  Similarly, a solid portion 430 is also formed in the stacked bodies 405c and 405d, and is formed in a U shape along the heat seal portion 407 in an inner region adjacent to the heat seal portion 407 on the bottom surface side. Although omitted in FIGS. 15 and 16 for convenience of illustration, a heat seal portion 407 is formed on the entire periphery of the edge of the laminate 405e, and the heat seal portion 407 is formed in an inner region adjacent to the heat seal portion 407. A solid portion 430 arranged in a rectangular shape is formed.

  Therefore, according to the configuration of the second modification, the solid portion 430 is formed in the inner region in the vicinity of the intersection between the inner end edge 412e of the bottom side gusset folding portion 405e and the heat seal portion 407 on the periphery of the bag body 401. As a result, even in the three-sided gusset type bag body 401, it is possible to sufficiently improve the compression resistance. In addition, the solid portion 430 is formed in a U shape in the stacked bodies 405a to 405d and is formed in a rectangular shape in the stacked body 405e, thereby improving the compression resistance and further improving the reliability. be able to.

  In the first embodiment described above, only the method of manufacturing the flat pouch bag 1 has been described. However, the present invention is not limited to the flat pouch bag 1, and the bag parts 201, 301, 401 similarly have a solid portion in advance. It is possible to bond the formed laminate by heat sealing after setting it in a bag making machine.

5a, 5b, 105, 205, 305a, 305b, 405a to 405e Laminate 7a to 7d, 107a, 207, 307a, 307b, 407 Heat seal part 30a to 30d, 130a, 130b, 230, 330, 430 ... Solid 102a, 302a, 412e Inner edge 204 Port plug 231 Port plug mounting portion

Claims (5)

In a bag formed by heat-sealing the peripheral edge of a film-like laminate including at least a foamed resin layer,
A bag body, wherein a solid portion formed by crushing the foamed resin layer is disposed in an inner region in the vicinity of a heat seal portion where the laminate is heat sealed.   The bag according to claim 1, wherein the solid portion is disposed in an inner region in the vicinity of an intersection between the gusset fold line and the heat seal portion.   The bag according to claim 1 or 2, wherein the solid portion is disposed in an inner region in the vicinity of the plug mounting portion to which the plug is mounted.   A laminated body forming the bag according to any one of claims 1 to 3, wherein a solid part is formed at least in part. It is a manufacturing method of the bag object according to any one of claims 1 to 3,
Forming a solid portion in advance in the laminate;
And a step of molding the bag by heat-sealing the laminate.

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