Pouch container and method for manufacturing pouch container

Abstract

Provided is a pouch container in which elongation is suppressed and which is excellent in mechanical suitability.　A pouch container 1 comprises a wall part extending in a longitudinal direction L and having a width of 11 cm or less in a width direction W orthogonal to the longitudinal direction L, the wall part including a uniaxially stretched polyethylene film stretched in the longitudinal direction L.

Description

Pouch container and method for manufacturing pouch container

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to pouch containers and methods of manufacturing pouch containers.

[0002] As a conventional pouch container, U.S. Patent No. 8,806,843 (Patent Document 1) discloses a container having a pair of side walls, a bottom wall, a top wall, and a spout attached to the top wall. Such a pouch container is manufactured by joining multiple strip-shaped films while conveying them. International Publication No. 2022 / 158133 (Patent Document 2) also discloses a technology for manufacturing a pouch container by conveying a single belt-shaped film member to which a spout is attached and joining a tubular film member to the film member.

[0003] U.S. Patent No. 8,806,843 International Publication No. 2022 / 158133

[0004] In recent years, from the perspective of reducing environmental impacts such as recycling, the use of polyethylene film for pouch containers instead of conventional substrate films made of polyethylene terephthalate, polyamide, etc. has been considered. However, polyethylene film is easily stretched, and when a narrow strip of film is used, deformation during transportation makes stable production difficult. When an opening is made in a film member, the periphery of the opening is prone to stretching. In particular, when attaching a spout to a top wall, a process is required to form an attachment hole (opening) in the strip of film member that will become the top wall. If no countermeasures are taken, the spout may stretch in the direction of force acting during transportation, making stable bag production difficult.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and an object of the present disclosure is to provide a pouch container that suppresses elongation and has excellent mechanical suitability, and a method for manufacturing a pouch container.

[0006] A pouch container according to a first aspect of the present disclosure includes a wall portion extending in a longitudinal direction, having a width of 11 cm or less in a width direction perpendicular to the longitudinal direction, and having an opening, the wall portion including a uniaxially oriented polyethylene film stretched in the longitudinal direction.

[0007] In the pouch container according to the present disclosure, the wall portion may be a top wall portion, and in this case, a spout may be attached to the opening provided in the top wall portion.

[0008] In the pouch container according to the present disclosure, the maximum width of the opening in the width direction may be between 1 / 3 and 2 / 3 of the width of the top wall portion in the width direction.

[0009] In the pouch container according to the present disclosure, the uniaxially oriented polyethylene film has a density of 0.94 g / cm ３ 0.97g / cm or more ３ It may be made of the following high density polyethylene.

[0010] In the pouch container according to the present disclosure, the wall may include a biaxially oriented polyethylene film laminated to the uniaxially oriented polyethylene film, and the biaxially oriented polyethylene film may be stretched in the longitudinal direction and the width direction.

[0011] A pouch container according to a second aspect of the present disclosure includes a wall extending in a longitudinal direction. A spout is attached to an opening provided in the wall. The wall includes a uniaxially oriented polyethylene film stretched in the longitudinal direction. The tensile elongation at break of the wall in the longitudinal direction is 170% or less. The elastic modulus of the wall in the longitudinal direction is 400 MPa or more.

[0012] A method for manufacturing a pouch container according to the present disclosure includes the steps of: conveying, along the longitudinal direction, a film sheet including a uniaxially oriented polyethylene film that extends in the longitudinal direction and has a width of 11 cm or less in a width direction perpendicular to the longitudinal direction; forming an opening in the film sheet; and joining another film sheet to the film sheet with the opening formed therein that is being conveyed, to form a bag body.

[0013] According to the present disclosure, it is possible to provide a pouch container that is suppressed in elongation and has excellent mechanical suitability, and a method for manufacturing the pouch container.

[0014] 1 is a diagram showing a state after filling of contents in a pouch container according to an embodiment. FIG. 2 is a diagram showing a folded state before filling of contents in a pouch container according to an embodiment. FIG. 3 is a schematic cross-sectional view taken along line III-III shown in FIG. 2. FIG. 4 is a cross-sectional view of a top wall portion of a pouch container according to an embodiment. FIG. 5 is a schematic view for explaining a predetermined manufacturing process of a pouch container according to an embodiment. FIG. 6 is a diagram showing a part of a manufacturing process of a pouch container according to an embodiment. FIG. 7 is a diagram showing a modified example of a manufacturing process of a pouch container. FIG. 8 is a diagram showing conditions of a verification experiment. FIG. 9 is a diagram showing conditions and results of a verification experiment.

[0015] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0016] (Pouch container) Fig. 1 is a diagram showing a pouch container according to an embodiment in a state after being filled with contents. Fig. 2 is a diagram showing a pouch container according to an embodiment in a folded state before being filled with contents. Fig. 3 is a schematic cross-sectional view taken along line III-III shown in Fig. 2. A pouch container 1 according to an embodiment will be described with reference to Figs. 1 to 3.

[0017] 1 to 3, the pouch container 1 according to the embodiment is a so-called spout-type pouch. More specifically, the pouch container 1 is a so-called small standing pouch having a bottom wall made of a bottom gusset and a top wall serving as an upper surface, and the width of a top wall portion 14 described below is 11 cm or less.

[0018] The pouch container 1 includes a first wall 11 and a second wall 12 as body walls, a bottom wall 13, and a top wall 14. The pouch body 10 of the pouch container 1 is illustrated as being made of multiple sheets of film (each wall being made of a sheet of film), but is not limited thereto. For example, the body wall and the bottom wall 13 may be made of a single sheet of film.

[0019] The first wall 11 and the second wall 12 respectively constitute the front and back surfaces of the container. The bottom wall 13 is inserted between the first wall 11 and the second wall 12 at the lower side and constitutes a bottom gusset. In the folded state shown in Figures 2 and 3, the bottom wall 13 is folded back toward the interior of the container along a crease 15 formed along the longitudinal direction L. The dimension of the width direction W of the bottom wall 13 before folding (when the bottom gusset is opened and flat) is 11 cm or less (5.5 cm or less in the state shown in Figure 2). The top wall 14 constitutes the upper surface of the container. The length of the top wall 14 in the longitudinal direction L is longer than the width direction W perpendicular to the longitudinal direction L. Note that, in the pouch container 1 before being filled with contents, the width direction W is approximately parallel to the direction from the lower end to the upper end of the second wall 12.

[0020] The pouch container 1 has a storage space 17 for storing contents between a first wall portion 11 and a second wall portion 12 that face each other in the thickness direction. The thickness direction is approximately parallel to the width direction W after the contents are filled. When the contents are filled into the storage space 17, the bottom wall portion 13 unfolds, allowing the pouch container 1 to stand on its own. The contents to be filled may be, for example, liquid, granular, or powdery. Notches 13c are formed on both edges of the bottom wall portion 13 that are parallel to the longitudinal direction L.

[0021] A plug 30 for filling or removing contents is provided in the center of the top wall 14. The plug 30 is composed of a spout 31 fixed to the top wall 14 and a cap 32 screwed onto a threaded portion formed on the outer periphery of the spout 31. Note that Fig. 2 shows the spout 31 with the cap 32 removed.

[0022] The top wall 14 extends in the longitudinal direction. In the folded state before filling with contents, the width W of the top wall 14, perpendicular to the longitudinal direction L, is 11 cm or less. More specifically, the width of the top wall 14 is 5 cm or more and 11 cm or less. If the width exceeds 11 cm, problems such as conveyance deviation due to stretching and wrinkles or waves caused by stretching are unlikely to occur when tension is applied to the film sheet constituting the top wall 14 during the manufacturing process (bag-making process) described below. However, if the width is 11 cm or less, problems are likely to occur. As described above, in the case of a small pouch container having a top wall 14 with a width of 11 cm or less, more specifically, a narrow width of 5 cm or more and 11 cm or less, the occurrence of the above problems can be effectively suppressed during manufacturing, as described below. The longitudinal length of the top wall 14 is, for example, approximately 10 cm to 20 cm.

[0023] The top wall 14 has an opening 14h to which the spout 31 is attached. The maximum width of the opening 14h in the width direction is between ⅓ and ⅔ of the width of the top wall 14 in the width direction. For example, the maximum width of the opening 14h is approximately 2.5 cm to 3.6 cm. Note that although a circular shape is shown as an example of the shape of the opening 14h, it is not limited to this. Any suitable shape, such as a rectangular shape, an elliptical shape, an oval shape, or a polygonal shape, can be used as the shape.

[0024] The spout 31 has a cylindrical portion 31a that protrudes outward from the top wall portion 14 and a flange portion 31b that is integrally formed at the end of the cylindrical portion 31a. The flange portion 31b is joined to the inner surface of the top wall portion 14 (i.e., the surface on the storage space 17 side) by thermocompression bonding or the like. The flange portion 31b may have any suitable shape, such as a rectangular shape, a circle, an ellipse, an oval shape, or a polygon.

[0025] The melting point (Tc) of the spout 31 may be higher than the melting point (Tb) of the innermost layer of the bag body 10 and lower than the melting point (Ta) of the outermost layer of the bag body 10 (Tb<Tc≦Ta). The innermost layer of the bag body 10 is, for example, a fourth film 54 (see FIG. 4) described below. The outermost layer of the bag body 10 is, for example, a first film 51 (see FIG. 1) described below. A heat-resistant coating may be applied to the surface of the outermost first film 51.

[0026] The spout 31 is obtained by injection molding a polyethylene resin. Although HDPE (high density polyethylene) can be used for the spout 31, LLDPE (linear low density polyethylene), which can be welded at low temperatures, is preferable. The spout 31 may also be LDPE (low density polyethylene). Furthermore, LLDPE provides better welding strength than LDPE, making it easier to adjust the welding temperature in the process of welding the spout 31 to the bag body 10, and thus suppressing deformation of the spout 31.

[0027] The melting point (Tc) of the spout 31 is preferably 100°C or higher and 135°C or lower, and more preferably 110°C or higher and 130°C or lower.

[0028] The pouch container 1 comprises a top seal portion 20, a bottom seal portion 21, a side seal portion 22, a lower point seal portion 19a, and an upper point seal portion 19b.

[0029] The top seal 20 joins the peripheral edge of the ceiling wall 14 to the upper edge of the first wall 11 and the upper edge of the second wall 12. The bottom seal 21 joins the peripheral edge of the bottom wall 13 to the lower edge of the first wall 11 and the lower edge of the second wall 12.

[0030] The side seal portions 22 join the first wall portion 11 and the second wall portion 12 on both sides in the longitudinal direction L. Specifically, the side seal portions 22 join the side edges of the first wall portion 11 and the second wall portion 12 on both sides in the longitudinal direction L. The side seal portions 22 extend in the up-down direction.

[0031] The lower point seal portions 19a are formed at the boundary between the bottom seal portion 21 and the side seal portion 22 on both sides in the longitudinal direction L. The lower point seal portions 19a are provided so as to straddle both the bottom seal portion 21 and the side seal portion 22.

[0032] The upper point seal portions 19b are formed at the boundaries between the top seal portion 20 and the side seal portion 22 on both sides in the longitudinal direction L. The upper point seal portions 19b are provided so as to straddle both the top seal portion 20 and the side seal portion 22.

[0033] Fig. 4 is a cross-sectional view of the top wall portion of the pouch container according to the embodiment. As shown in Fig. 4, the top wall portion 14 includes a first film 51, a second film 52, a third film 53, and a fourth film 54. The first film 51 to the fourth film 54 are layered in order from the outside to the inside.

[0034] The first film 51 is made of machine-direction oriented polyethylene (MDOPE) stretched in the longitudinal direction. The first film 51 is stretched, for example, about 2 to 10 times in the longitudinal direction. The longitudinal direction is the direction parallel to the longitudinal direction L of the top wall 14. In other words, the first film 51 is a uniaxially stretched polyethylene film stretched in the longitudinal direction L, and has little elongation in the longitudinal direction.

[0035] The first film 51 contains high-density polyethylene as a main component. The high-density polyethylene is contained in the first film 51 in a proportion of, for example, 50% to 100% of the resin component, preferably 70% to 100%. The first film 51 may contain other polyethylene-based resins and additives such as lubricants and antioxidants. The first film 51 has a density of 0.94 g / cm ３ 0.97g / cm or more ３ The first film 51 is made of the following high-density polyethylene: The density of the high-density polyethylene contained in the first film 51 is, for example, 0.94 g / cm ３ 0.97g / cm or more ３More particularly, the density is 0.94 g / cm ３ 0.96g / cm or more ３ The following is the result.

[0036] The second film 52 is laminated on the first film 51. The first film 51 and the second film 52 are overlapped with each other in the thickness direction of the first film 51 and the second film 52. The second film 52 is disposed further inside the bag body 10 than the first film 51. The second film 52 is bonded to the first film 51 with an adhesive such as dry lamination. The second film 52 may be bonded to the first film 51 by extrusion lamination using a polyethylene resin. Letters and a design may be printed on the second film 52 side of the first film 51. Letters and a design may be printed on the outside or inside of the second film 52.

[0037] The second film 52 is preferably made of transverse direction oriented polyethylene (TDOPE) stretched in the transverse direction or biaxial direction oriented polyethylene (BOPE) stretched in both the longitudinal and transverse directions. The transverse direction is perpendicular to the longitudinal direction and parallel to the width direction.

[0038] The second film 52 functions as a reinforcing layer that reinforces the first film 51. Since the first film 51 is prone to tearing in the longitudinal direction, laminating the above-mentioned transversely oriented polyethylene or biaxially oriented polyethylene can increase its strength. The second film 52 is formed of high-density polyethylene, medium-density polyethylene, low-density polyethylene, or linear low-density polyethylene. The second film 52 preferably contains high-density polyethylene or medium-density polyethylene as its main component. The second film 52 may also contain other polyethylene-based resins or additives.

[0039] The third film 53 is laminated on the second film 52. The third film 53 and the second film 52 are overlapped with each other in the thickness direction of the third film 53 and the second film 52. The third film 53 is disposed more inward of the bag body 10 than the second film 52.

[0040] The third film 53 functions as a barrier layer. The barrier layer is a layer of polyethylene resin imparted with barrier properties, and examples of such a layer include a film (LDPE / EVOH / LDPE) obtained by co-extruding low-density polyethylene and ethylene vinyl alcohol (EVOH), a film obtained by coating a polyethylene resin film with a barrier agent (for example, a solution of polyvinyl alcohol resin mixed with inorganic layered particles), and a film obtained by vapor-depositing silicon oxide, aluminum oxide, aluminum, or the like onto a polyethylene film to impart barrier properties. The thickness of the ethylene vinyl alcohol (EVOH) layer of the co-extruded film (LDPE / EVOH / LDPE) may be 3 μm to 10 μm.

[0041] The fourth film 54 is laminated on the third film 53. The fourth film 54 and the third film 53 are overlapped with each other in the thickness direction of the fourth film 54 and the third film 53. The fourth film 54 is disposed on the opposite side of the third film 53 from the first film 51.

[0042] The fourth film 54 is disposed inside the bag body 10 relative to the third film 53. The fourth film 54 defines the storage space 17.

[0043] The fourth film 54 is provided as a sealant layer when the sheet-like packaging material is formed into a bag by a heat-sealing process. The fourth film 54 is made of a heat-sealable resin that can be welded by heating. The fourth film 54 is made of a polyolefin resin such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, or polypropylene. The fourth film 54 is particularly preferably made of linear low-density polyethylene.

[0044] The tensile breaking elongation along the longitudinal direction L of the top wall portion 14 in which the first film 51 to the fourth film 54 are laminated in this manner is 170% or less. The tensile breaking elongation in the longitudinal direction L may be 40% or less. By setting the tensile breaking elongation to such a value, when a narrow strip-shaped film having a width of 11 cm or less is transported in a bag-making process or the like and processed for opening or the like, stretching, wrinkling, and the like are less likely to occur, and the machine suitability is improved.

[0045] The elastic modulus of the top wall portion 14 in the longitudinal direction L is 400 MPa or more. The elastic modulus of the top wall portion 14 in the longitudinal direction L is preferably 700 MPa or more. The elastic modulus of the top wall portion 14 in the width direction W may be 470 MPa or more. By setting the elastic modulus to such a value, stretching, wrinkling, etc. are less likely to occur and machine suitability is improved when a narrow strip-shaped film having a width of 11 cm or less is transported and opened in a bag-making process or the like.

[0046] The tensile elongation at break and the modulus of elasticity can be determined, for example, by a method in accordance with JIS-K-7161.

[0047] The thickness of the first film 51 may be, for example, 10 μm or more and 50 μm or less, or 10 μm or more and 30 μm or less. The thickness of the second film 52 may be, for example, 10 μm or more and 50 μm or less, or 10 μm or more and 30 μm or less. The thickness of the first film 51 may be less than the thickness of the second film 52, or may be greater than the thickness of the second film 52. The thickness of the first film 51 may be the same as the thickness of the second film 52.

[0048] The thickness of the third film 53 and the thickness of the fourth film 54 may be, for example, 20 μm or more and 200 μm or less, or 30 μm or more and 150 μm or less.

[0049] The bottom wall 13 may be configured in the same manner as the top wall 14. That is, the bottom wall 13 may include the first film 51 to the fourth film 54. In this case, too, the first film 51 is uniaxially stretched in a direction parallel to the longitudinal direction of the top wall 14.

[0050] The first wall portion 11 and the second wall portion 12 may also include the first film 51 to the fourth film 54. In this case, the first film 51 is also uniaxially stretched in a direction parallel to the longitudinal direction of the top wall portion 14. In the first wall portion 11 and the second wall portion 12, the lateral direction of the film corresponds to the up-down direction of the pouch container 1. If the top wall portion 14, the bottom wall portion 13, the first wall portion 11, and the second wall portion 12 are all formed from laminated films made of a polyethylene-based resin, and the spout is also formed from a polyethylene-based resin, the pouch container will have excellent recyclability. 90% by weight or more of the entire pouch container 1 may be formed from a polyethylene-based resin.

[0051] (Manufacturing Method) Fig. 5 is a schematic diagram for explaining a predetermined manufacturing process for the pouch container according to the embodiment. Fig. 6 is a diagram showing a part of the manufacturing process for the pouch container according to the embodiment.

[0052] The pouch container 1 includes a process of preparing multiple film sheets (film sheet 60, third film sheet 63, fourth film sheet 64), a process of transporting the multiple film sheets, a process of joining the multiple film sheets to form a bag body, and a process of cutting out individual bag bodies.

[0053] As shown in Figures 5 and 6, the pouch container manufacturing apparatus 100 includes a spout supply device 70, a cutting device 110, a conveying guide 120, a folding device 130, a conveying guide 140, a hole punching device 150, a first joining device 160, a conveying guide 170, a folding device 180, a hole punching device 190, a second joining device 191, a third joining device 192, and a cutting device 193.

[0054] Each of the prepared film sheets (film sheet 60, third film sheet 63, fourth film sheet 64) is set in a predetermined position in a rolled state. Film sheet 60 is a member that constitutes first wall portion 11 and second wall portion 12. Third film sheet 63 is a member that constitutes bottom wall portion 13. Fourth film sheet 64 is a member that constitutes top wall portion 14. The third film sheet 63 and fourth film sheet 64 each have a width of 11 cm or less in the width direction perpendicular to the conveying direction. The longitudinal direction of top wall portion 14 is parallel to the conveying direction.

[0055] At least the fourth film sheet 64 of the multiple film sheets includes the first film 51 to the fourth film 54 described above, and the first film 51 is uniaxially stretched in a direction parallel to the conveying direction. The third film sheet 63 and the film sheet 60 may also have a similar configuration to the fourth film sheet 64.

[0056] In the process of transporting a plurality of film sheets, film sheet 60, third film sheet 63, and fourth film sheet 64 are transported as follows.

[0057] The film sheet 60 is continuously transported in a strip shape and is cut into a first film sheet 61 and a second film sheet 62 by a cutting device 110 along the transport path. The first film sheet 61 is a sheet member that forms the first wall portion 11, and the second film sheet 62 is a sheet member that forms the second wall portion 12.

[0058] Each of the first film sheet 61 and the second film sheet 62 is conveyed toward the overlapping position P1 by a conveyance guide 120. The first film sheet 61 is folded by a folding device 130. As a result, a flange portion 64c is formed on the first film sheet 61 on one side in a direction perpendicular to the conveyance direction.

[0059] The third film sheet 63 has a strip-like shape extending in the longitudinal direction, and is transported between the first film sheet 61 and the second film sheet 62 by a transport guide 170. The third film sheet 63 is transported between the first film sheet 61 and the second film sheet 62 in a folded state by a folding device (not shown). The third film sheet 63 is positioned on the opposite side of the flange portion 64c in a direction perpendicular to the transport direction. During transport, through holes 63h are formed in the third film sheet 63 at predetermined intervals by a punching device 190. The through holes 63h are cut to form the notches 13c.

[0060] The fourth film sheet 64 has a strip-like shape extending in the longitudinal direction and is transported by the transport guide 140. The fourth film sheet 64 is transported onto the flange portion 64c. More specifically, the fourth film sheet 64 is transported so as to overlap the flange portion 64c and the portion of the second film sheet 62 that is exposed from the first film sheet 61.

[0061] The step of transporting the fourth film sheet 64 includes the step of attaching the spout 31 to the fourth film sheet 64. The spout 31 is attached to the fourth film sheet 64 before it is transported onto the first film sheet 61 and the second film sheet 62.

[0062] Specifically, opening 14h for attaching spout 31 is formed in fourth film sheet 64 by hole punching device 150. Next, spout 31 is supplied from spout supply device 70 toward opening 14h, and tubular portion 31a is inserted into opening 14h. Next, flange portion 31b of spout 31 is joined to the periphery of opening 14h using first joining device 160, which performs ultrasonic welding or thermal welding.

[0063] The fourth film sheet 64 is conveyed over the first film sheet 61 and the second film sheet 62 as described above, with the spouts 31 attached thereto at predetermined intervals.

[0064] Next, a process of joining multiple film sheets to form a bag is carried out. In this process, film sheet 60, third film sheet 63, and fourth film sheet 64 are joined by second joining device 191. Specifically, the regions of the multiple film sheets where the top seal portion 20, bottom seal portion 21, and side seal portion 22 are to be formed are heat-sealed by second joining device 191 to form each seal portion. Note that top seal portion 20, bottom seal portion 21, and side seal portion 22 may be formed simultaneously or separately, and each seal may be formed in multiple steps by heat compression bonding or cold compression bonding, for example. By forming top seal portion 20, bottom seal portion 21, and side seal portion 22, a bag is formed.

[0065] Subsequently, the lower point seal portion 19a and the upper point seal portion 19b are formed by a third joining device 192. The lower point seal portion 19a and the upper point seal portion 19b may be formed simultaneously or separately.

[0066] Next, a process of cutting out individual bag bodies is carried out. Specifically, a group of bags arranged in a row in the conveyance direction is cut at predetermined intervals using a cutting device 193, and individualized pouch containers 1 are taken out. Through the above processes, the pouch container 1 is manufactured. Note that a process of cutting off the outer periphery of the top seal portion 20, etc., can be performed in combination with each of the above processes. The manufactured pouch container 1 can be used by filling the bag body with predetermined contents through the spout 31 and attaching the cap 32 to the spout 31.

[0067] It should be noted that the above-described manufacturing method is not limited to the example in which the first film sheet 61 and the second film sheet 62 are cut out from the film sheet 60, and the third film sheet 63 and the fourth film sheet 64 are each formed from a film sheet separate from the film sheet 60. The third film sheet 63 and the fourth film sheet 64 may also be cut from the film sheet 60 and supplied.

[0068] 7 is a diagram showing a modified example of the manufacturing process of the pouch container. A modified example of the manufacturing process of the pouch container 1 will be described with reference to FIG.

[0069] 7, a fourth film sheet 64 having a spout 31 attached thereto may be joined to a tubular bag body 210, which has a first wall portion 11, a second wall portion 12, and a bottom wall portion 13 joined together in advance, so as to close the opening of the tubular bag body 210. The bag body 10 may be formed in this manner.

[0070] More specifically, the belt-shaped fourth film sheet 64 is transported in the transport direction (DR1 direction) above the tubular bag body 210. An opening 14h is formed in the portion of the fourth film sheet 64 that will become the top wall portion 14, and the spout 31 is provided therein.

[0071] The tubular bag bodies 210 are transported to the joining station ST1 in the transport direction (DR2 direction) below the fourth film sheet 64. The joining station ST1 is an area where the fourth film sheet 64 and the tubular bag bodies 210 are joined. The tubular bag bodies 210 are transported one by one to the joining station ST1 and joined to the fourth film sheet 64.

[0072] The tubular bag body 210 is transported to the joining station ST1 with the joining margin 214 expanded. The joining margin 214 is formed by folding back the first wall 11 and the second wall 12 in portions located above the upper end of the side seal portion 22.

[0073] The fourth film sheet 64 and the tubular bag body 210 are joined by a joining device 191A. The joining device 191A includes a pair of joining heads 191B and 191C. These joining heads 191B and 191C sandwich and thermocompress the joining margin 214 of the tubular bag body 210 and the portion of the fourth film sheet 64 that overlaps the joining margin 214, thereby forming the bag body 10. Note that further point sealing, cutting of the outer shape, etc. may be performed as appropriate.

[0074] In the pouch container 1 obtained through the manufacturing process described above, in the first wall portion 11 and the second wall portion 12, the vertical direction of the pouch container 1 corresponds to the horizontal direction of the packaging material (first film sheet 61 and second film sheet 62) that constitutes the pouch container 1, and the left-right direction (the longitudinal direction of the top wall portion 14) that is perpendicular to the vertical direction of the pouch container 1 corresponds to the vertical direction of the packaging material that constitutes the pouch container 1.

[0075] On the other hand, in the bottom wall portion 13 and the top wall portion 14, the width direction W corresponds to the horizontal direction of the packaging material (third film sheet 63 and fourth film sheet 64) that constitutes the pouch container 1, and the longitudinal direction L corresponds to the vertical direction of the packaging material that constitutes the pouch container 1.

[0076] The first film 51 made of longitudinally uniaxially stretched polyethylene has excellent strength in the longitudinal direction and mechanical suitability that suppresses pitch deviation and the like caused by elongation during the production of the pouch container 1. In particular, the longitudinally uniaxially stretched polyethylene has a density of 0.94 g / cm ３ 0.97g / cm or more ３ When made of the following high density polyethylene, the strength in the longitudinal direction can be further increased.

[0077] On the other hand, the first film 51 made of longitudinally uniaxially oriented polyethylene has inferior strength in the horizontal direction compared to its strength in the vertical direction, and therefore when used alone, it has the property of being easily torn in the vertical direction when subjected to an external force in the horizontal direction. In contrast, in this embodiment, by laminating the second film 52, a packaging material with high strength in both the vertical and horizontal directions can be obtained.

[0078] Furthermore, by using a film sheet containing the above-mentioned longitudinally uniaxially oriented polyethylene for the top wall 14, which is provided with the opening 14h for attaching the spout 31, stretching of the film sheet in the conveying direction during manufacturing can be suppressed, even when the opening 14h is provided. This improves machine suitability. In this case, even when the top wall 14 has a large opening ratio relative to the width of the top wall 14, such that the maximum width of the opening 14h in the width direction is between one-third and two-thirds of the width of the top wall 14 in the width direction, in order to provide a large-diameter spout, stretching of the film sheet can be effectively suppressed.

[0079] Furthermore, in this embodiment, when a narrow width that is difficult to transport, such as a width of 11 cm or less in the width direction, is used, and the tensile breaking elongation of the film sheet including the above-mentioned longitudinally uniaxially stretched polyethylene film stretched in the longitudinal direction is set to 170% or less, and the elastic modulus of the film sheet is set to 400 MPa or more, it is possible to suppress the elongation of the film sheet that needs to be transported in a narrow width, enabling stable transport and improving machine suitability.

[0080] (Verification Experiment) Fig. 8 is a diagram showing the conditions of the verification experiment. Fig. 9 is a diagram showing the conditions and results of the verification experiment. The verification experiment will be described with reference to Figs. 8 and 9.

[0081] 8 and 9, film sheets according to Comparative Example 1 and Examples 1 to 3 were prepared for the verification experiment. The prepared film sheet was slit to a width of 6 cm and used as the fourth film sheet 64. An opening 14h with a diameter of 2.5 cm was formed in the fourth film sheet 64 using the apparatus having the pouch container manufacturing process described above, and a spout made of polyethylene was joined to produce the pouch container 1. During this process, the machine suitability (bag-making suitability) of each film sheet was evaluated.

[0082] (Film Sheet Conditions) The layer structure of each film sheet according to Comparative Example 1 and Examples 1 to 3 was as shown in Figure 8, and the measured values ​​of the tensile elongation at break and modulus of elasticity of each film sheet were as shown in Figure 9. The measurements were performed by cutting each film sheet to a width of 15 mm, setting the chuck distance of the testing machine to 100 mm, and using a "method in accordance with JIS-K-7161."

[0083] Specifically, in Comparative Example 1, a non-stretched high-density polyethylene (HDPE) film was used as the surface base material layer (first film 51), and no reinforcing layer (second film 52) was used. The above-mentioned polyethylene (PE)-based barrier layer (a film vapor-deposited with an inorganic oxide) was used as the barrier layer (third film 53), and a non-stretched film of linear low-density polyethylene (LLDPE) was used as the sealant layer (fourth film 54).

[0084] The thickness of the film sheet in Comparative Example 1 was approximately 142 μm. Regarding the tensile elongation at break of the film sheet in Comparative Example 1, the tensile elongation at break in the machine direction (the longitudinal direction L) was 400% or more, and the tensile elongation at break in the transverse direction (the width direction W) was 83%. Regarding the elastic modulus at room temperature of the film sheet in Comparative Example 1, the elastic modulus in the machine direction (the longitudinal direction L) was 601 MPa, and the elastic modulus in the transverse direction (the width direction W) was 549 MPa.

[0085] In Example 1, a high-density polyethylene (HDPE) uniaxially stretched polyethylene film in the longitudinal direction (longitudinal direction L) was used as the surface base layer (first film 51), and a biaxially stretched polyethylene film in the longitudinal and transverse directions (width direction W) was used as the reinforcing layer (second film 52). The above-mentioned polyethylene (PE)-based barrier layer (co-extruded polyethylene-based film) was used as the barrier layer (third film 53), and an unstretched film of linear low-density polyethylene (LLDPE) was used as the sealant layer (fourth film 54).

[0086] The thickness of the film sheet in Example 1 was approximately 150 μm. Regarding the tensile elongation at break of the film sheet in Example 1, the tensile elongation at break in the machine direction (the longitudinal direction L) was 38%, and the tensile elongation at break in the transverse direction (the width direction W) was 47%. Regarding the elastic modulus of the film sheet in Example 1 at room temperature, the elastic modulus in the machine direction (the longitudinal direction L) was 912 MPa, and the elastic modulus in the transverse direction (the width direction W) was 932 MPa.

[0087] In Example 2, a longitudinally (longitudinal direction L) uniaxially stretched high-density polyethylene (HDPE) film was used as the surface base layer (first film 51), and no reinforcing layer (second film 52) was used. The barrier layer (third film 53) was the above-mentioned polyethylene (PE)-based barrier layer (co-extruded polyethylene-based film), and the sealant layer (fourth film 54) was an unstretched film of linear low-density polyethylene (LLDPE).

[0088] The thickness of the film sheet in Example 2 was approximately 137 μm. Regarding the tensile elongation at break of the film sheet in Example 2, the tensile elongation at break in the machine direction (the longitudinal direction L) was 162%, and the tensile elongation at break in the transverse direction (the width direction W) was 69%. Regarding the elastic modulus of the film sheet in Example 2 at room temperature, the elastic modulus in the machine direction (the longitudinal direction L) was 757 MPa, and the elastic modulus in the transverse direction (the width direction W) was 482 MPa.

[0089] In Example 3, a uniaxially stretched high-density polyethylene (HDPE) film in the longitudinal direction (longitudinal direction L) was used as the surface base layer (first film 51), and a biaxially stretched polyethylene film in the longitudinal and transverse directions (width direction W) was used as the reinforcing layer (second film 52). The above-mentioned polyethylene (PE)-based barrier layer (co-extruded polyethylene-based film) was used as the barrier layer (third film 53), and an unstretched film of linear low-density polyethylene (LLDPE) was used as the sealant layer (fourth film 54).

[0090] The thickness of the film sheet in Example 3 was approximately 190 μm. Regarding the tensile elongation at break of the film sheet in Example 3, the tensile elongation at break in the machine direction (the longitudinal direction L) was 137%, and the tensile elongation at break in the transverse direction (the width direction W) was 41%. Regarding the elastic modulus of the film sheet in Example 3 at room temperature, the elastic modulus in the machine direction (the longitudinal direction L) was 443 MPa, and the elastic modulus in the transverse direction (the width direction W) was 582 MPa.

[0091] (Evaluation of bag-making suitability in pouch container manufacturing equipment) In Comparative Example 1, suitability evaluation in equipment having the above-mentioned pouch container manufacturing process was determined to be unsuitable. Specifically, in Comparative Example 1, the film sheet stretched significantly during conveyance, making it difficult to stably manufacture pouch containers. In Comparative Example 1, even when the production speed (conveyance speed) was reduced, the film sheet stretched, making it impossible to stably manufacture pouch containers. In other words, in Comparative Example 1, the stretching of the film sheet could not be suppressed, and the machine suitability was poor.

[0092] In Example 1, the suitability evaluation for the apparatus having the above-described pouch container manufacturing process was judged to be good. Specifically, in Example 1, pouch containers could be stably manufactured without reducing the production speed. That is, in Example 1, the elongation of the film sheet could be effectively suppressed, and the mechanical properties were particularly excellent.

[0093] In Example 2, the suitability evaluation for the apparatus having the above-mentioned pouch container manufacturing process was judged to be acceptable. Specifically, in Example 2, pouch containers could be stably manufactured by slowing down the production speed. That is, in Example 2, the stretching of the film sheet could be suppressed to a considerable extent, and the mechanical properties were excellent.

[0094] In Example 3, the suitability evaluation for the apparatus having the above-mentioned pouch container manufacturing process was judged to be acceptable. Specifically, in Example 3, pouch containers could be stably manufactured by slowing down the production speed. That is, in Example 3, the elongation of the film sheet could be suppressed to a considerable extent, and the mechanical properties were excellent.

[0095] Comparing the results of Comparative Example 1 and Examples 1 to 3 above, it was confirmed that in pouch container 1, the wall portion made of a strip-shaped film having a narrow width in the width direction perpendicular to the longitudinal direction contains a uniaxially stretched film stretched in the longitudinal direction, thereby suppressing elongation and providing excellent mechanical suitability.

[0096] In addition, even when an opening 14h is provided in the top wall portion 14 and a spout 31 is attached to the opening 14h, it has been confirmed that the film sheet is prevented from stretching during manufacturing, and that the film sheet has excellent mechanical suitability.

[0097] Furthermore, the uniaxially oriented polyethylene film contained in the film sheet is 0.94 g / cm ３ 0.97g / cm or more ３ By forming it from the following high density polyethylene, the density is 0.94 g / cm ３ It was confirmed that the elongation under tension is suppressed compared to low density polyethylene etc., and that the mechanical properties are excellent.

[0098] It was also confirmed that laminating a biaxially oriented polyethylene film to the uniaxially oriented polyethylene film contained in the film sheet suppresses elongation and provides excellent mechanical suitability.

[0099] In the fourth film sheet 64, which becomes the top wall portion 14, it has been confirmed that by setting the tensile breaking elongation of the sheet in the longitudinal direction to 170% or less and the elastic modulus of the sheet in the longitudinal direction to 400 MPa or more, elongation is suppressed and the sheet has excellent mechanical suitability.

[0100] Comparing Example 1 with Examples 2-3, it was confirmed that by setting the elastic modulus of the sheet in the longitudinal direction to 700 MPa or more, elongation is suppressed even when the thickness of the film sheet is reduced, and dimensional fluctuations are small and stable even when tension changes occur during transport, resulting in excellent mechanical suitability.

[0101] Comparing Example 1 with Examples 2-3, it was confirmed that by setting the modulus of elasticity of the sheet in the width direction to 900 MPa or more, elongation was effectively suppressed and excellent mechanical suitability was achieved.

[0102] In the above embodiment, the wall portion extending in the longitudinal direction, having a width of 11 cm or less, and having an opening is the top wall portion 14. However, such a wall portion is not limited to the top wall portion 14. Through holes 63h are also formed at predetermined intervals in the third film sheet 63 of the bottom wall portion 13 by the hole punching device 190 during conveyance, and the same effect as described above can be obtained with such a bottom wall portion 13. Furthermore, the present invention can be applied to a pouch container having a top wall portion 14 but no bottom wall portion 13, or a pouch container having no top wall portion 14 but a bottom wall portion 13. Furthermore, the present invention can also be applied to a pouch container having an opening provided in the side gusset portion of a side gusset pouch. The present invention may also be applied to a pouch container having a spout provided in the bottom wall portion 13 or the side gusset portion. In the above-described embodiment, the wall portions such as the top wall portion 14 are formed of film sheets in which the first film 51, the second film 52, the third film 53, and the fourth film 54 are laminated in this order, but the film sheets may be formed of film sheets in which the second film 52, the first film 51, the third film 53, and the fourth film 54 are laminated in this order. Furthermore, the film sheets may not include the third film 53.

[0103] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, and includes all modifications within the meaning and scope of the claims.

[0104] DESCRIPTION OF SYMBOLS 1 Pouch container, 10 Bag body, 11 First wall portion, 12 Second wall portion, 13 Bottom wall portion, 14 Top wall portion, 14h Opening portion, 15 Fold line, 17 Storage space, 19a Lower point seal portion, 19b Upper point seal portion, 20 Top seal portion, 21 Bottom seal portion, 22 Side seal portion, 30 Spout, 31 Spout, 31a Cylinder portion, 31b Flange portion, 32 Cap, 51 First film, 52 Second film, 53 Third film, 54 Fourth film, 60 Film sheet, 61 First film sheet, 62 Second film sheet, 63 Third film sheet, 63h Through hole, 64 Fourth film sheet, 64c Flange portion, 70 Spout supply device, 100 Pouch container manufacturing device, 110 Cutting device, 120 Conveying guide, 130 Folding device, 140 conveying guide, 150 punching device, 160 first joining device, 170 conveying guide, 180 folding device, 190 punching device, 191 second joining device, 191A joining device, 191B perturbation head, 191C joining head, 192 third joining device, 193 cutting device, 210 bag body.

Claims

1. A pouch container, comprising a wall portion extending in a longitudinal direction, having a width of 11 cm or less in a width direction orthogonal to the longitudinal direction, and provided with an opening, wherein the wall portion includes a uniaxially stretched polyethylene film stretched in the longitudinal direction.

2. The pouch container according to claim 1, wherein the wall portion is a top wall portion, and a spout is attached to the opening provided in the top wall portion.

3. The pouch container according to claim 2, wherein a maximum width of the opening in the width direction is 1 / 3 or more and 2 / 3 or less of a width of the top wall portion in the width direction.

4. The uniaxially oriented polyethylene film is made of high-density polyethylene with a density of 0.94 g / cm ３ or more and 0.97 g / cm ３ or less, and the pouch container according to any one of claims 1 to 3.

5. The pouch container according to any one of claims 1 to 3, wherein the wall portion includes a biaxially stretched polyethylene film laminated on the uniaxially stretched polyethylene film, and the biaxially stretched polyethylene film is stretched in the longitudinal direction and the width direction.

6. A pouch container including a wall portion extending in a longitudinal direction, wherein a spout is attached to an opening provided in the wall portion, the wall portion includes a uniaxially stretched polyethylene film stretched in the longitudinal direction, an elongation at break in the longitudinal direction of the wall portion is 170% or less, and a modulus of elasticity in the longitudinal direction of the wall portion is 400 MPa or more.

7. A method for manufacturing a pouch container, comprising: a step of conveying a film sheet including a uniaxially stretched polyethylene film extending in a longitudinal direction and having a width of 11 cm or less in a width direction orthogonal to the longitudinal direction along the longitudinal direction; a step of forming an opening in the film sheet; and a step of joining another film sheet to the film sheet in which the opening is formed and conveyed to form a bag body.

Images