The present invention relates to a pouch container packaging and also to a pouch container.
Pouch containers are commonly used as containers for beverages such as sports drinks and for foods such as ice cream and jelly. Patent Document 1 discloses an example of a conventional pouch container.
To be able to hermetically hold substances, such as beverages and foods mentioned above, the packaging X has a top-edge central seal 94, top-edge side seals 95, side seals 96, a bottom seal 97, and oblique seals 98. The top-edge central seal 94 is formed by joining the pair of outer films 91 along the top edges with the spout 93 sandwiched between protons of the top edges . The top-edge side seals 95 are formed by joining the pair of outer films 91 to the pair of gusset films 92 along the top edges. The side seals 96 are formed by joining the pair of outer films 91 to the pair of gusset films 92 along the side edges. The bottom seal 97 is formed by joining the pair of outer films 91 along the respective bottom edges. The oblique seals 98 are formed by joining the pair of outer films 91 to the pair of gusset films 92 along the oblique edges. The packaging X is such that an inner edge 96a of each side seal 96, an inner edge 97a of the bottom seal 97, and an inner edge 98a of each oblique seal 98 are substantially parallel to their outer edges and are straight throughout their length.
A method for producing a pouch container using a packaging X may include a leak testing step to check for leakage prior to a step of filling with an above-mentioned substance. In the leak testing step, a nozzle Nz shown in
Unfortunately, the leak testing step may cause an oblique seal 98 to be turned back as shown in
After completion of the leak testing step, the interior space of the packaging X is evacuated and thus the packaging X becomes flat again. Subsequently, the step of filling the packaging with the substance is performed. An edge once turned back in the leak testing step has a crease that remains even after the packaging is flat again. As such, it often happens that the edge is unintentionally turned back again during the filling step. A pouch container having such a turned back edge involves a risk of unintentional stress applied to the bottom during, for example, a transportation step, and a consequent risk of leakage. This may undesirably result in leakage of the substance from a pouch container X despite that the pouch container is produced by using the packaging X determined to be leakage free in the leak testing step.
Patent Document 1: JP-A-2000-344252
The present invention has been conceived in view of the above circumstances and aims to provide a packaging for a pouch container as well as a pouch container capable of effectively preventing an oblique edge from turning back and reducing the risk of leakage of the substance from the pouch container.
According to a first aspect of the present invention, there is provided a packaging for a pouch container, which includes: a pair of outer films disposed on a front side and a back side with a filling-and-pouring member sandwiched at a top, where the outer films each have side edges, a bottom edge and oblique edges lying between the side edges and the bottom edge; and
a pair of gusset films each disposed in a folded state between the outer films and having side edges and oblique edges. The side edges of the outer films and the side edges of the gusset films are joined to provide side seals, the bottom edges of the respective outer films are joined to provide a bottom seal, and the oblique edges of the outer films and the oblique edges of the gusset films are joined to provide oblique seals. The oblique seals each have an inner edge at least a part of which is curved.
According to a preferred embodiment of the present invention, each oblique seal has a narrow-width portion that is narrower in width than ends of the oblique seal.
According to a preferred embodiment of the present invention, the inner edge of each oblique seal has a curved portion continuous with an inner edge of a side seal.
According to a preferred embodiment of the present invention, the inner edge of each oblique seal has a curved portion continuous with an inner edge of the bottom seal.
According to a preferred embodiment of the present invention, the entirety of the inner edge of each oblique seal is curved.
According to a second aspect of the present invention, there is provided a pouch container that includes a packaging according to the first aspect of the invention; and a substance contained in the packaging.
According to the present invention, at least a portion of the inner edge of each oblique seal is curved. With this arrangement, the stress on the oblique seal along the entire length of the inner edge is not uniform in the longitudinal direction but varies gradually in accordance with the shape of the curve. This serves to prevent the stress on the inner edge of the oblique seal from being rapidly concentrated at the end connected to an end of the side seal and at the end connected to an end of the bottom seal, ensuring the stress to be distributed. Consequently, the oblique seals are prevented from turning back and the bottom seal is prevented from rising. Therefore, a pouch container produced by using the packaging can significantly reduce the risk of leakage of the substance as compared with a conventional pouch container.
Other features and advantages of the present invention will become more apparent from detailed description given below with reference to the accompanying drawings.
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. In the description, the front of a pouch container is toward a customer when the pouch container holding the contents is placed to stand upright on a store shelve. Further, the back of the pouch container is opposite to the front, the sides are in the right and left directions, the top is in a vertically upward direction, and the bottom is in a vertically downward direction. An outer surface of each film of a pouch container refers to a surface exposed to the outside, and an inner surface refers to the opposite surface. In addition, an up-and-down direction refers to the vertical direction of the pouch container standing upright, and a width direction refers to the right-and-left direction.
The pair of outer films 1 are disposed on the front and the back to sandwich the spout 3 at the top. Each outer film 1 according to the present embodiment is generally hexagonal as seen from the front and has a top edge that extends in the width direction at the top, two side edges that are spaced apart in the width direction and extend in the up-and-down direction, a bottom edge that extends in the width direction at the bottom, and two oblique edges each connecting the lower end of a side edge to the upper end of a bottom edge.
The pair of gusset films 2 are each located between the pair of outer films 1 in a state folded along a fold line 21. Each gusset film 2 has a top edge, two side edges, and two oblique edges and is generally pentagonal when unfolded. In addition, the gusset film 2 has cutaway portions 22 at either end of the top edge.
The pair of outer films 1 and the pair of gusset films 2 are typically formed from resin films. The resin films are required to have properties expected for a packaging material, including impact resistance, abrasion resistance, and heat resistance. Typically, the seals described above are formed by heat sealing, and thus the sheets are required to have heat sealing properties suitable for that. Appropriate sheets include a multilayer sheet of a base-film layer and a sealant layer that imparts the heat sealing properties . Ina case where high gas impermeability and light-shielding characteristics are required, an appropriate multilayer sheet may be provided with a barrier layer between the base-film layer and the sealant layer. Alternatively, the base-film layer per se may be imparted with barrier characteristics. In this case, the barrier layer acts as the base-film layer, and thus the multilayer sheet includes the barrier layer and the sealant layer.
The following lists examples of component materials of the base-film layer, sealant layer, and gas barrier layer.
These layers can be stacked through a conventional lamination technique, examples of which include co-extrusion lamination, dry lamination with adhesive, thermal lamination of thermally bonding layers via a heat-sensitive adhesive layer sandwiched in between.
Examples of the base-film layer include single-and multi-layer films, either oriented or non-oriented, made from polyester (such as, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polybutylene terephthalate (PBT), and polycarbonate (PC)), polyolefin (such as polyethylene (PE) and polypropylene (PP)), polyamide (such as Nylon-6 and Nylon-66) , polyacrylonitrile (PAN) , polyimide (PI), polyvinyl chloride (PVC), polyvinylidene chloride (PVDC), polymethyl methacrylate (PMMA), and polyethersulfone (PES).
Examples of the sealant layer include single-and multi-layer films, either oriented or non-oriented, made from low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), ethylene-propylene copolymer (EP), cast polypropylene (CPP), bi-axially oriented nylon (ON), ethylene-olefin copolymer, ethylene acrylic acid (EAA) copolymer, ethylene-methyl methacrylate (EMMA) copolymer, and ethylene-vinyl acetate (EVA) copolymer.
Examples of the gas barrier layer include: a thin film of metal such as aluminum; or a film of resin such as polyvinylidene chloride (PVDC), ethylene vinyl alcohol (EVOH) copolymer and any synthetic resin (which may be the base-film layer), each film of resin having a deposited (or sputtered) layer of aluminum or inorganic oxide such as aluminum oxide or silica.
The outer films 1 or the gusset films 2 may be provided with a print layer (not shown) for printing of information related to the substance, including the product name, row materials, and product description, such as precautions for use, in addition to various patterns and designs. In one example, the print layer may be provided on the inner surface of the base-film layer by a known method such as gravure printing.
The top-edge central seal 41 is formed by heat sealing to join the pair of outer films 1 centrally along the top edges. The top-edge central seal 41 is located between the pair of gusset films 2. In the present embodiment, the spout 3 is sandwiched at the center of the top-edge central seal 41. The top edges of the pair of outer films 1 and the spout 3 are hermetically joined by, for example, heat sealing.
Each top-edge side seal 42 is formed by heat sealing to join a side end of the top edge of an outer film 1 to a side end of the top edge of a gusset film 2 . In the present embodiment, the pair of outer films 1 and the pair of gusset films 2 form four top-edge side seals 42 in total.
Each side seal 43 is formed by heat sealing to join a side edge of an outer film 1 to a side edge of a gusset film 2 and extends in the up-and-down direction. In the present embodiment, the pair of outer films 1 and the pair of gusset films 2 form four side seals 43 in total.
The bottom seal 44 is formed by heat sealing to join the pair of outer films 1 along the respective bottom edges and extends in the width direction. The bottom seal 44 is located between the pair of gusset film 2.
Each oblique seal 45 is formed by heat sealing to join an oblique edge of an outer film 1 to an oblique edge of a gusset film 2. The oblique seal 45 extends obliquely relative to both the up-and-down direction and the width direction. In the present embodiment, the pair of outer films 1 and the pair of gusset films 2 form four oblique seals 45 in total. The two oblique seals 45 located on the same side in terms of the width direction are continuous with the same widthwise end of the bottom seal 44.
Each side seal 43 has an inner edge 43a, the bottom seal 44 has an inner edge 44a, and each oblique seals 45 has an inner edge 45a. In the present embodiment, the inner edge 43a is a straight line in the up-and-down direction throughout its length. The inner edge 44a is a straight line in the width direction throughout its length. The inner edge 45a is curved outward throughout its length. In other words, the inner edge 45a is curved at any portions, including a portion continuous with the inner edge 43a of the side seal 43, a portion continuous with the inner edge 44a of the bottom seal 44, and an intermediate portion located in between. In
Each oblique seal 45 is structured to have a smaller width W3 around the middle than widths W1 and W2 at the ends. This is because the inner edge 45a is defined by an outward curve at least partly, and indeed entirely in the present embodiment.
In the present embodiment, the packaging A1 has two sealed shoulders 46. The sealed shoulders 46, which are located at the intersections of the top edge with the side edges, are formed by heat sealing to join the inner surfaces of the pair of outer films 1 at portions exposed through the cutaway portions 22 in the gusset film 2.
The spout 3 is a hollow member made of, for example, resin and defines a path through which the substance is poured in and out . The spout 3 has a tubular portion through which the substance is poured in and out and a boat-shaped welding portion joined to the sheet packaging body. The spout 3 is secured to the pair of outer films 1 with the boat-shaped welding portion hermetically sealed between the pair of outer films 1 at the top-edge central seal 41. The spout 3 corresponds to a filling-and-pouring member according to the present invention.
First, as shown in
The packaging A1, which is in a flat state, is subjected to the filling step using a conventionally known technique. Through this, the packaging A1 filled with the substance Lq is obtained as a pouch container B1 shown in
Next, effects of the packaging A1 are described.
The conventional packaging X often experiences a turned back edge in the leak testing step. Although the cause is not fully identified, the following is a possible explanation. In the leak testing step of the conventional packaging X shown in
Based on the above findings, each oblique seal 45 according to the present embodiment has a curved inner edge 45a as shown in
Each oblique seal 45 has a portion having the width W3, which is smaller than the width W1 or W2 at the end portions. That is, the inner edge 45a of the oblique seal 45 defines an outward curve. Through the study of the present inventors, it has been found that such an outwardly curved contour is effective to prevent occurrences of turned back edges.
The method for producing a pouch container may be modified to fill the packaging with the substance without performing the leak testing step. However, the filling step still involves the risk that the oblique seals 45 are turned back and the bottom seal 44 is raised. Therefore, in such a method, providing the oblique seals 45 with the inner edges 45a that are at least partly curved is likewise effective to prevent the oblique seals 45 from turning back and the bottom seal 44 from raising.
Table 1 blow shows the results of tests conducted on the packagings A1 to A5 according to the present invention, the conventional packaging X shown in
The packagings A1 to A5 are structured as described above. The packaging X is structured as shown in
In the packaging C1 shown in
In the packaging C3 shown in
The test results about the occurrences of turned back edges shown in Table 1 were obtained on 50 samples of the individual packagings, namely the packagings A1 to A5, X, and C1 to C4. Each sample was subjected to the leak testing step to visually check the oblique seals 45 for any turned back edge.
As shown in Table 1, the conventional packaging X exhibited the occurrence rate of 51%, whereas the packagings A1 to A5 according to the present invention all exhibited the occurrence rates ranging from 21% to 38%, which are lower than the rate obtained on the packaging X. That is, the occurrences of turned back edges were reduced by providing the oblique seal 45 having an inner edge 45a at least partly curved. In particular, the packagings A1, A2, and A3 respectively exhibited the occurrence rates of 21%, 23%, and 25%, each of which is about a half of the occurrence rate of the packaging X . That is , the occurrences of turned back edges were sufficiently reduced. This is assumed to be a result achieved by the inner edges 45a being entirely curved. In the packagings A3 and A4, each inner edge 45a is curved only at a portion toward the bottom seal 44. As demonstrated by the occurrence rate of 38%, these packagings still achieved the effect of reducing the occurrences of turned back edges. Comparison between the packaging A3 and the packaging A4 reveals that the occurrences of turned back edges were reduced more effectively by providing a curve at the connection between the inner edge 43a of the side seal 43 and the inner edge 45a of the oblique seal 45 than at the connection between the inner edge 44a of the bottom seal 44 and the inner edge 45a of the oblique seal 45. The packaging A5 has the inner edges 45a curved only at a central portion while the portions closer to the ends are straight lines. The packaging A5 having such a structure was still effective to reduce the occurrences of turned back edges, as demonstrated by the occurrence rate of 31%. This shows that the inner edge 45a not curved at the ends is still effective to distribute the stress, which would otherwise be concentrated at the respective ends of the inner edge 45a (at the intersections with the inner edges 43a and 44a).
Referring now to the comparative examples C1 to C4, the occurrence rates range from 51% to 73%, which are at most comparable to the occurrence rates obtained on the conventional packaging X. These results show that the occurrences of turned back edges at the oblique seal 45 cannot be reduced or may even be increased as long as the inner edges 45a are composed only of straight lines, regardless of the shapes and locations of the inner edges 45a. As set forth above, the packaging according to the present invention has an inner edge 45a that is at least partly curved as exemplified by the packagings A1 to A5 and achieves the effect of preventing the oblique seals 45 from turning back.
The pouch container packaging according to the present invention is not limited to the embodiments described above. Various design changes can be made to the specific structure of the packaging for a pouch container according to the present invention.
Number | Date | Country | Kind |
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2013-202654 | Sep 2013 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2014/065892 | 6/16/2014 | WO | 00 |