Cylindrical packaging body

Abstract

Provided is a cylindrical packaging body that is filled with contents and is sealed, the cylindrical packaging body having easy-to-open properties and resistance to heat sterilization treatment, the easy-to-open properties facilitating removal of the contents from the cylindrical packaging body, and the resistance to heat sterilization treatment preventing, during heat sterilization treatment, peeling of a longitudinal seal portion of the cylindrical packaging body, curl deformation of ear portions (outer ear portions and / or inner ear portions) and an opening piece, etc., of a cylindrical member, and breakage or even rupture, etc., of the cylindrical packaging body.　The ratio Do / Di of a distance Do from an end portion CA, on an outer thick-walled portion 11a1 side, of a longitudinal seal portion 11c of an outer piece 11a to an end portion A of the outer thick-walled portion 11a1 on the opposite side to the seal portion side, and a distance Di from an end portion CB, on an inner thick-walled portion 11b1 side, of the longitudinal seal portion 11c of an inner piece 11b to an end portion B of the inner thick-walled portion 11b1 on the opposite side to the longitudinal seal portion 11c side is greater than 0 and at most equal to 1.11 when the cylindrical packaging body is filled with contents on the inner peripheral side of a cylindrical member 10.

Description

Tubular packaging

[0001] The present invention relates to a cylindrical package filled with solid or paste-like processed foods such as fish sausage, processed cheese, kamaboko, etc., and particularly to a joining structure of a cylindrical resin film. Furthermore, the present invention relates to a cross-sectional shape of the joining portion of the package, i.e., the vertically sealed portion, in a direction perpendicular to the longitudinally sealed portion.

[0002] A known conventional tubular packaging body includes a tubular member formed from a resin film in a tubular shape, the tubular member having a laminated portion in which one end of the strip-shaped resin film in the width direction is positioned radially outward and the other end is positioned radially inward, and the laminated portion has a vertical seal portion in which parts of an outer piece having an outer end that is the end positioned radially outward and an inner piece having an inner end that is the end positioned radially inward are joined to each other along the longitudinal direction of the tubular member.

[0003] Furthermore, when a resin film extruded into a tube shape is made into a strip-shaped resin film, two layers of strip-shaped resin film having a predetermined width can be obtained by overlapping the insides of the two layers together, and by cutting them longitudinally as necessary, a strip-shaped resin film having the desired width can be produced (see, for example, Patent Document 1).

[0004] The cylindrical packaging body has a structure in which the inner periphery of the cylindrical member is filled with solid or paste-like processed foods such as fish sausage, processed cheese, kamaboko, etc. as contents, and both ends of the cylindrical member are bundled and sealed with metal wire clips such as aluminum wire clips, resin horizontal sealing films, or other means.

[0005] For the vertical seal portion to form a tubular member from the strip-shaped resin film, methods such as welding by high-frequency dielectric heating, ultrasonic heating, laser heating, resistance heating, heat sealing, or bonding with an adhesive are used depending on the characteristics of the resin, and known forms of the vertical seal portion include so-called gusset sealing and envelope sealing.

[0006] When removing the contents from the tubular packaging, the outer end (also called the outer ear) of the laminated portion is pinched with the fingers and force is applied radially outward from the tubular member, thereby breaking the seal or the area near the seal and exposing the contents.

[0007] However, when removing the contents from conventional cylindrical packaging, part of the seal extending in the axial direction of the cylindrical member may remain unbroken, resulting in a defective opening where the entire contents cannot be removed in one piece.

[0008] Methods have been considered for making it easier to remove the contents from a tubular packaging body by adjusting the shape and structure of the vertical seal that extends in the longitudinal direction of the tubular member, and it is known to provide an outer ear on the outside of the vertical seal and provide holes, slits, or scars in the outer ear, but this has the problem of increasing costs and requiring additional processes. Therefore, there has been a demand for a tubular packaging body that is easy to open, making it easy to remove the contents from the tubular packaging body.

[0009] For example, cylindrical packages filled with contents such as processed foods are heat-sterilized using a heat treatment device at a temperature of 80°C or higher and / or under pressure, allowing fish sausage, for example, to be stored at room temperature for 90 days. Heat-sterilization conditions include, for example, a temperature of 80 to 150°C, a pressure of 0 to 0.4 MPa (gauge pressure), and a time of 1 to 60 minutes. During heat-sterilization, volumetric expansion of the contents and possible thermal shrinkage or deformation of the cylindrical member or tear strip can cause peeling of the vertical seal of the cylindrical member, curling of the ears (outer ear and / or inner ear) of the cylindrical member or the tear strip, and even rupture of the cylindrical package.

[0010] If a sealed portion of a tubular package peels or breaks, the contents may deteriorate due to the inflow of outside air, resulting in a risk of not obtaining a product of normal quality. Furthermore, if the ears or tear strip of the tubular member are deformed, further damage may occur during handling or transportation of the tubular package, which may impair the product's appearance and reduce consumer interest, or interfere with removing the contents from the tubular package. Furthermore, if the vertical seal of the tubular package peels, the ears (outer ears and / or inner ears) of the tubular member or the tear strip curl, or the tubular package breaks or even bursts during heat sterilization, operation must be stopped to remove the damaged product, resulting in reduced production efficiency. Therefore, there has been a demand for a tubular package that is resistant to heat sterilization and does not suffer from peeling of the vertical seal of the tubular package, curling of the ears (outer ears and / or inner ears) of the tubular member or the tear strip, or breakage or even bursting of the tubular package during heat sterilization.

[0011] However, if the seal strength of the vertical seal of the tubular member is increased in order to make the tubular packaging resistant to heat sterilization treatment, the ease of opening of the tubular packaging is impaired, and the ease of opening and the resistance to heat sterilization treatment of the tubular packaging are often in conflict with each other. Attempts have been made to use a specific layer structure or to use multiple vertical seals, but these are not simple and do not sufficiently achieve both ease of opening and resistance to heat sterilization treatment (see, for example, Patent Document 2).

[0012] That is, there has been a demand for a tubular packaging body that is filled with and sealed with contents, and that has easy-open properties that allow the contents to be easily removed from the tubular packaging body, and that has resistance to heat sterilization treatment that prevents peeling of the vertical seal of the tubular packaging body, curling deformation of the ears (outer ears and / or inner ears) of the tubular member or the opening flap, and breakage or even rupture of the tubular packaging body during heat sterilization treatment.

[0013] JP 2015-164860 A JP 2019-073306 A

[0014] An object of the present invention is to provide a tubular packaging body that is filled and sealed with contents, and that has easy-open properties to allow the contents to be easily removed from the tubular packaging body, and that is resistant to heat sterilization treatment so that, during heat sterilization treatment, the vertical seal of the tubular packaging body does not peel off, the ears (outer ears and / or inner ears) of the tubular member or the opening flap does not curl or deform, and the tubular packaging does not break or even burst.

[0015] The cylindrical packaging body of the present invention is a cylindrical packaging body including a cylindrical member formed by shaping a resin film into a cylindrical shape, the cylindrical member having a laminated portion in which a strip-shaped resin film is laminated so that an end on one side in the width direction is positioned radially outward and an end on the other side is positioned radially inward, the laminated portion having an outer piece positioned radially outward and an inner piece positioned radially inward, the outer piece and the inner piece having a vertical seal portion formed by joining parts of each of the outer piece and the inner piece together along the longitudinal direction of the cylindrical member, the outer piece having a portion in the resin film on the base film side of the vertical seal portion that is formed to have a thickness dimension (radially) larger than another portion located closest to the end of the vertical seal portion. an outer thick portion is formed in the vertical seal portion, and an inner thick portion is formed in the resin film on the base film side of the vertical seal portion in a portion that is formed to have a thickness dimension (radial direction) larger than other portions closest to the end of the vertical seal portion, and the ratio Do / Di of the distance Do from the end (CA) of the vertical seal portion in the outer piece on the outer thick portion side to the end (A) of the outer thick portion on the opposite side to the vertical seal portion side, and the distance Di from the end (CB) of the vertical seal portion in the inner piece on the inner thick portion side to the end (B) of the inner thick portion on the opposite side to the vertical seal portion side, is greater than 0 and not more than 1.11 when the contents are filled on the inner peripheral side of the tubular member.

[0016] Furthermore, it is preferable that the tubular packaging body of the present invention is subjected to a heat sterilization treatment at a temperature of 80°C or higher and 150°C or lower, a pressure of 0 MPa or higher and 0.4 MPa or lower (gauge pressure), and a time of 1 minute or higher and 60 minutes or lower, while the contents are filled on the inner circumferential side of the tubular member.

[0017] Furthermore, it is preferable that the tubular packaging body of the present invention has a distance in the laminated portion from the end of the outer thick portion of the outer piece opposite the vertical seal portion to the end of the inner thick portion of the inner piece opposite the vertical seal portion, of 200 μm or more and 800 μm or less.

[0018] In the tubular packaging body of the present invention, it is preferable that the tubular member is formed into a tubular shape by a single vertical seal portion.

[0019] In the cylindrical packaging body of the present invention, the resin film is preferably a heat-shrinkable film containing polyvinylidene chloride.

[0020] According to the present invention, by pinching the end of the outer piece of the laminated portion with the fingers and applying force radially outward from the tubular member, it is possible to reliably tear the section from any point between the end (CB) on the inner thick portion of the vertical seal and the end (B) of the inner thick portion opposite the vertical seal, to any point on the outer side toward the end (A) of the outer thick portion opposite the vertical seal, or from any point between the end (CB) on the inner thick portion of the vertical seal and the end (B) of the inner thick portion opposite the vertical seal, to any point on the inner side facing the end (CA) of the outer thick portion of the vertical seal, and the section, without causing any opening defects, thereby making it possible to easily remove the contents from the tubular member. Furthermore, as described above, the present invention has the effect of providing a tubular packaging body that is easy to open, allowing the contents to be easily removed, and that is resistant to heat sterilization treatment so that the vertical seal of the tubular packaging body does not peel off, the ears (outer ears and / or inner ears) of the tubular member or the opening flap do not curl or deform, and the tubular packaging does not break or even burst during heat sterilization treatment.

[0021] Fig. 1 is a schematic diagram of a tubular packaging body filled with contents according to one embodiment of the present invention. Fig. 2 is a schematic cross-sectional view showing the positional relationship of a laminated portion, an outer piece, an inner piece, and a vertical seal portion in a tubular member according to one embodiment of the present invention. Fig. 3 is a cross-sectional view of a main part of a tubular packaging body according to one embodiment of the present invention.

[0022] Figures 1 to 3 show one embodiment of the present invention, where Figure 1 is a schematic diagram of a tubular packaging body filled with contents, Figure 2 is a schematic cross-sectional view showing the positional relationship of the laminated portion, outer piece, inner piece and vertical seal portion in the tubular member, and Figure 3 is a cross-sectional view of a main part of the tubular packaging body.

[0023] The cylindrical packaging body 1 of this embodiment is intended to accommodate solid or paste-like processed foods such as fish sausage, processed cheese, kamaboko, etc. as contents.

[0024] 1, the cylindrical packaging body 1 includes a cylindrical member 10 formed by forming a resin film into a cylindrical shape, and is formed by sealing both ends of the cylindrical member 10 with metal clips 20 such as aluminum wire clips while the contents are filled inside the cylindrical member 10. In some cases, instead of metal clips such as aluminum wire clips, both ends of the cylindrical member 10 are bundled and sealed with a resin horizontal sealing film or other means.

[0025] From the viewpoints of excellent oxygen barrier properties and a balance between heat resistance and strength, the tubular member 10 is preferably formed from a film made of a resin containing, for example, a polyvinylidene chloride resin. Furthermore, from the viewpoint of achieving both sealability and resistance to heat sterilization treatment, the resin film forming the tubular member 10 of the present invention is preferably a heat-shrinkable film containing polyvinylidene chloride.

[0026] The polyvinylidene chloride resin (hereinafter sometimes referred to as "PVDC") preferably used as the resin film forming the tubular member 10 may be a homopolymer of vinylidene chloride, but is usually a copolymer of 60 to 98% by mass of vinylidene chloride and 2 to 40% by mass of another monomer copolymerizable with vinylidene chloride. Examples of other monomers copolymerizable with vinylidene chloride include vinyl chloride; alkyl acrylate esters (alkyl group having 1 to 18 carbon atoms) such as methyl acrylate, ethyl acrylate, butyl acrylate, and lauryl acrylate; alkyl methacrylate esters (alkyl group having 1 to 18 carbon atoms) such as methyl methacrylate, butyl methacrylate, and lauryl methacrylate; vinyl cyanide such as acrylonitrile; aromatic vinyl such as styrene; vinyl esters of aliphatic carboxylic acids having 1 to 18 carbon atoms such as vinyl acetate; alkyl vinyl ethers having 1 to 18 carbon atoms; vinyl-polymerizable unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, and fumaric acid; and alkyl esters (including partial esters, alkyl group having 1 to 18 carbon atoms) of vinyl-polymerizable unsaturated carboxylic acids such as maleic acid, fumaric acid, and itaconic acid. At least one selected from vinyl chloride, methyl acrylate, and lauryl acrylate is more preferred. The other monomers copolymerizable with vinylidene chloride may be used alone or in combination of two or more. The copolymerization ratio of the other monomer is more preferably 3 to 35% by mass, even more preferably 3 to 25% by mass, and particularly preferably 4 to 22% by mass. If the copolymerization ratio of the other monomer is too low, the melt processability tends to decrease, while if the copolymerization ratio of the other monomer is too high, the gas barrier properties tend to decrease. Furthermore, two or more types of PVDC may be mixed to improve melt processability.

[0027] The PVDC preferably used in the present invention can be synthesized by any polymerization method, such as suspension polymerization, emulsion polymerization, or solution polymerization. However, when forming a compound as a powder resin, synthesis by suspension polymerization is preferred. Synthesis by suspension polymerization tends to eliminate the need for a grinding process to adjust the particle size of the powder resin made of PVDC. The particle size of such a powder resin made of PVDC is preferably in the range of 40 μm to 2 mm, more preferably in the range of 50 μm to 1 mm, and even more preferably in the range of 60 to 700 μm. The particle size of the powder resin is measured, for example, by dry sieving using a standard sieve.

[0028] The resin material of the resin film forming the tubular member 10, preferably PVDC, can contain various additives such as heat stabilizers, plasticizers, processing aids, colorants, UV absorbers, pH adjusters, and dispersing aids, which are conventionally added to resin films formed into the tubular member 10 for the purpose of improving various properties and moldability.

[0029] Furthermore, the resin material of the resin film forming the tubular member 10, preferably PVDC, may contain other resins such as polyethylene wax, oxidized polyethylene wax, polyethylene (low-density polyethylene or high-density polyethylene), ethylene-vinyl acetate copolymer, acrylic acid ester homopolymer or copolymer, methacrylic acid ester homopolymer or copolymer, methyl methacrylate-butadiene-styrene copolymer, etc., as needed, for the purpose of improving various properties and moldability. The acrylic acid ester or methacrylic acid ester is preferably an alkyl ester in which the alkyl group has 1 to 18 carbon atoms.

[0030] The properties, shape, and size of the other resin can be appropriately selected as desired, taking into consideration the uniform dispersibility with the resin material forming the cylindrical member 10. For example, the other resin may be in a solid form such as granular, powdery, or pellet form, or may be in a liquid or molten state. Furthermore, the surface of the other resin may be surface-treated as desired.

[0031] The size and thickness of the resin film forming the cylindrical member 10 are not particularly limited and are determined according to the size of the contents to be filled.

[0032] The circumferential length of the resin film forming the tubular member 10 is usually 15 to 400 mm, often 30 to 350 mm, commonly 40 to 250 mm, even more commonly 50 to 150 mm, and most commonly 40 to 120 mm.

[0033] The longitudinal length of the resin film forming the tubular member 10 is usually 50 to 400 mm, often 100 to 400 mm, commonly 120 to 360 mm, even more commonly 150 to 350 mm, and most commonly 150 to 330 mm.

[0034] The thickness of the resin film of the tubular member 10 is determined taking into consideration the strength and barrier properties of the film depending on the contents to be filled, but is usually 5 to 300 μm, often 10 to 200 μm, commonly 15 to 150 μm, even more commonly 18 to 150 μm, and most commonly 20 to 150 μm.

[0035] Furthermore, the resin film forming the cylindrical member 10 may be a heat-shrinkable film (a uniaxially stretched film or a biaxially stretched film).

[0036] Furthermore, a laminated film may be used to increase the strength of the resin film forming the cylindrical member 10, improve gas barrier properties, improve heat resistance, adjust shrinkage, and the like.

[0037] As shown in Figure 2, the tubular member 10 has a laminated portion 11 in which a strip-shaped resin film is laminated so that one end of the film in the width direction is positioned radially outward and the other end is positioned radially inward.

[0038] The tubular member 10 of the present invention can be obtained by a method employed for producing a tubular resin film for use in a conventional tubular packaging body. Specifically, the tubular member 10 is formed by winding a strip-shaped resin film into a cylindrical shape so that both longitudinally extending side edge portions (outer piece 11 a and inner piece 11 b) overlap, and then vertically sealing a portion of the both side edge portions (vertical seal portion 11 c) of the tubular film.

[0039] The method for producing the strip-shaped resin film used to form the tubular member 10 is not particularly limited. Typically, a sheet- or tubular-shaped extruded film is produced by extrusion molding, and if necessary, stretched to impart heat shrinkability. In the case of a tubular extruded film, two layers of the extruded film are stacked on top of each other to obtain a strip-shaped resin film having a predetermined width. If necessary, the two layers are cut longitudinally to produce a strip-shaped resin film having the desired width. When the tubular resin film is a laminated film, the strip-shaped resin film may be produced by laminating multiple films together using coextrusion molding or extrusion lamination, or by laminating multiple films with an adhesive, such as a urethane adhesive. If the tubular member 10 is to be printed, the resulting strip-shaped resin film may be printed.

[0040] As shown in FIG. 2, the laminated portion 11 has an outer piece 11a located on the radially outer side and an inner piece 11b located on the radially inner side.

[0041] A vertical seal portion 11c, which is a portion where the outer piece 11a and the inner piece 11b are joined to each other along the longitudinal direction of the tubular member 10, is formed in the middle portion in the width direction of each of the outer piece 11a and the inner piece 11b.

[0042] As shown in Figure 3, the outer piece 11a has an outer thick portion 11a1 formed in a portion of the resin film on the base film 10a side of the vertical seal portion 11c, which is formed to have a thickness dimension (radial direction) larger than other portions located closest to the end of the vertical seal portion 11c.

[0043] Here, the distance from an end CA of the outer piece 11a on the outer thick portion 11a1 side of the vertical seal portion 11c to an end A of the outer thick portion 11a1 opposite the vertical seal portion 11c side is defined as Do.

[0044] The end A of the outer thick portion 11a1 opposite the vertical seal portion 11c is a "L-shaped" bent portion between the outer thick portion 11a1 and other portions of the outer piece 11a, and is a singular point (a point on the curve where there are no tangents or two or more tangents) on the curve of the cross-sectional surface of the outer thick portion 11a1 (radially inside the outer thick portion 11a1).

[0045] Here, the base material film 10a refers to the film in the tubular member 10 excluding the resin film on both ends of the vertical seal portion 11c and the clips 20 at both ends of the longitudinal direction of the tubular member 10, and refers to the film in the portion that comes into direct contact with the contents.

[0046] As shown in Figure 3, the inner piece 11b has an inner thick portion 11b1 formed in a portion of the resin film on the base film 10a side of the vertical seal portion 11c, which is formed to have a thickness dimension (radial direction) larger than other portions located closest to the end of the vertical seal portion 11c.

[0047] Here, the distance from the end CB of the inner piece 11b on the inner thick portion 11b1 side of the vertical seal portion 11c to the end B of the inner thick portion 11b1 opposite the vertical seal portion 11c side is defined as Di.

[0048] The end B of the inner thick portion 11b1 opposite the vertical seal portion 11c is a "L-shaped" bent portion between the inner thick portion 11b1 and other portions of the inner piece 11b, and is a singular point (a point on the curve where there are no tangents or two or more tangents) on the curve of the cross-sectional surface of the inner thick portion 11b1 (radially outside the inner thick portion 11b1).

[0049] In the present invention, the ratio Do / Di of the distance Do from the end CA of the outer thick portion 11a1 of the vertical seal 11c of the outer piece 11a to the end A of the outer thick portion 11a1 opposite the vertical seal 11c, to the distance Di from the end CB of the inner thick portion 11b1 of the vertical seal 11c of the inner piece 11b to the end B of the inner thick portion 11b1 opposite the vertical seal 11c, is preferably greater than 0 and not greater than 1.14 when the contents are filled inside the tubular member 10. Furthermore, the ratio Do / Di is more preferably 0.50 to 1.14. Furthermore, the ratio Do / Di is most preferably 0.67 to 1.08.

[0050] Furthermore, the tubular packaging body 1 of the present invention is resistant to heat sterilization treatment performed during the manufacture of the tubular packaging body 1. Typical conditions for heat sterilization treatment include a temperature of 80°C to 150°C, a pressure of 0 MPa to 0.4 MPa (gauge pressure), and a time of 1 minute to 60 minutes. A heat sterilization time of 5 minutes to 60 minutes is more preferable. Retort heat sterilization, which is a heat sterilization treatment performed on the processed food contents packed inside the tubular member 10, is performed, for example, at a temperature of 100°C to 150°C and a pressure of 0.1 MPa to 0.4 MPa (gauge pressure) for a time of 1 minute to 60 minutes. Furthermore, boiling heat sterilization, which is a heat sterilization treatment, is performed, for example, at a temperature of 80°C to 100°C and a pressure of 0 MPa (gauge pressure) for a time of 30 minutes to 60 minutes.

[0051] In the present invention, when the contents are filled on the inner circumferential side of the cylindrical member 10, the ratio Do / Di after the retort sterilization heat treatment and the ratio Do / Di after the boiling heat sterilization treatment are preferably greater than 0 and not greater than 1.11. The ratio Do / Di is more preferably 0.10 or greater and 1.10 or less. Furthermore, the ratio Do / Di is most preferably 0.36 or greater and 1.06 or less.

[0052] The vertical seal portion 11c is provided for the same purpose as a vertical seal portion extending in the longitudinal direction that is provided on a tubular member that is conventionally provided on a tubular packaging body.

[0053] Typically, a strip of resin film is rolled into a cylindrical shape so that both longitudinal edge portions overlap to form a tubular film, and then the both longitudinal edge portions of the tubular film are continuously sealed (adhered) in the longitudinal direction (vertical direction) according to a conventional method such as high-frequency dielectric heating, ultrasonic heating, laser heating, resistance heating, welding by heat sealing, or bonding with an adhesive, thereby forming the tubular member 10.

[0054] The vertical seal portion 11c is provided over the entire length of the cylindrical member 10 in the longitudinal direction, and can preserve the contents filled and sealed in the cylindrical member 10 in a sealed state.

[0055] In the longitudinally extending laminated portion 11 provided in the tubular member 10, the distance from the end A opposite the vertical seal portion 11c side of the outer thick portion 11a1 to the end B opposite the vertical seal portion 11c side of the inner thick portion 11b1 is an important factor in making the vertical seal portion 11c easy to open.

[0056] The distance (AB) from end A to end B has a relationship expressed as Do+W+Di.

[0057] In the present invention, the distance (AB) from end A to end B is preferably 200 μm or more and 800 μm or less, and more preferably 250 μm or more and 650 μm or less.

[0058] If the distance (AB) is less than 200 μm, the seal strength will be insufficient, the resistance to heat sterilization treatment will tend to be poor, and the outer thick portion 11a1 and inner thick portion 11b1 that are characteristic of the present invention will be less likely to occur.

[0059] Furthermore, if the distance (AB) is greater than 800 μm, the ease of opening the package will be significantly reduced, resulting in a high incidence of defective opening.

[0060] Furthermore, the width W of the longitudinal seal portion 11c provided on the cylindrical member 10 and extending in the longitudinal direction can be determined appropriately depending on the sealing method, the resin used, and the like.

[0061] In the present invention, the width W of the vertical seal portion 11c is preferably 45 μm or more and 250 μm or less, and more preferably 45 μm or more and 130 μm or less.

[0062] If the width W of the vertical seal portion 11c is smaller than 45 μm, the seal strength will be insufficient and the resistance to heat sterilization treatment will tend to be poor.

[0063] Furthermore, if the width W of the vertical seal portion 11c is greater than 250 μm, the ease of opening tends to deteriorate, and the incidence of opening failures tends to increase.

[0064] The tubular packaging body 1 configured as described above is formed by filling the contents into the tubular member 10 and bundling both longitudinal ends of the tubular member 10 filled with the contents with clips 20, making it possible to store the contents in a sealed state.

[0065] When removing the contents from the cylindrical packaging body 1, the end (external ear) of the outer piece 11a of the laminated portion 11 is pinched with the fingers and a force is applied radially outward to the cylindrical member 10. As a result, the cylindrical member 10 is pulled outward from a portion between an arbitrary point between the end (CB) of the vertical seal portion 11c on the inner thick portion 11b1 side and the end (B) of the inner thick portion 11b1 on the opposite side to the vertical seal portion 11c side, or a portion between an arbitrary point on the outer piece 11a side from the end (CA) of the vertical seal portion 11c on the outer thick portion 11a1 side toward the end (A) of the outer thick portion 11a1 on the opposite side to the vertical seal portion 11c side, or The section between the end (CB) on the inner thick portion 11b1 side of the vertical seal portion 11c and the end (B) on the opposite side of the vertical seal portion 11c of the inner thick portion 11b1 and the end (CA) on the outer thick portion 11a1 side of the vertical seal portion 11c and the end (A) on the opposite side of the vertical seal portion 11c of the outer thick portion 11a1 breaks, making it possible to remove the contents from the tubular member 10.

[0066] In this case, if the ratio Do / Di of the distance Do from the end CA of the outer piece 11a on the outer thick portion 11a1 side of the vertical seal portion 11c to the end A of the outer thick portion 11a1 on the opposite side to the vertical seal portion 11c side, and the distance Di from the end CB of the inner thick portion 11b1 side of the vertical seal portion 11c to the end B of the inner thick portion 11b1 on the opposite side to the vertical seal portion 11c side, is greater than 0 and not more than 1.14 in a state in which the contents are filled on the inner peripheral side of the tubular member 10, then no opening defects will occur and an opening can be made from any point between the end (CB) of the vertical seal portion 11c on the inner thick portion 11b1 side to the end (B) of the inner thick portion 11b1 on the opposite side to the vertical seal portion 11c side. This makes it possible to reliably rupture the portion between the end (CA) of the vertical seal portion 11c on the outer thick portion 11a1 side and any point on the outer piece 11a side toward the end (A) of the outer thick portion 11a1 on the opposite side to the vertical seal portion 11c side, or the portion between the end (CB) of the vertical seal portion 11c on the inner thick portion 11b1 side and the end (B) of the inner thick portion 11b1 on the opposite side to the vertical seal portion 11c side and any point on the inner piece 11b side facing the end (CA) of the vertical seal portion 11c on the outer thick portion 11a1 side and the end (A) of the outer thick portion 11a1 on the opposite side to the vertical seal portion 11c side, making it possible to remove the entire contents from the tubular member 10 in one piece.

[0067] As described above, according to the cylindrical packaging body of this embodiment, the cylindrical packaging body 1 includes a cylindrical member 10 formed by shaping a resin film into a cylindrical shape, and the cylindrical member 10 has a laminated portion 11 formed by laminating strip-shaped resin films so that an end portion on one side in the width direction is positioned radially outward and an end portion on the other side is positioned radially inward, and the laminated portion 11 has an outer piece 11a positioned radially outward, an inner piece 11b positioned radially inward, and a vertical seal portion 11c formed by joining a portion of the outer piece 11a and the inner piece 11b to each other along the extension direction of the cylindrical member 10, and the outer piece 11a has a thickness dimension (diameter 11c) greater than another portion of the resin film on the base film 10a side of the vertical seal portion 11c that is closest to the end of the vertical seal portion 11c. The outer thick portion 11a1 is formed in a portion where the thickness dimension (radial direction) is larger than that of other portions of the resin film on the base film 10a side of the vertical seal portion 11c, and the inner thick portion 11b1 is formed in a portion where the thickness dimension (radial direction) is larger than that of other portions of the resin film on the base film 10a side of the vertical seal portion 11c. The ratio Do / Di of the distance Do from an end CA on the outer thick portion 11a1 side of the vertical seal portion 11c in the outer piece 11a to an end A of the outer thick portion 11a1 on the opposite side to the seal portion side, and the distance Di from an end CB on the inner thick portion 11b1 side of the vertical seal portion 11c in the inner piece 11b to an end B of the inner thick portion 11b1 on the opposite side to the vertical seal portion 11c side, is greater than 0 and not more than 1.11 when the contents are filled on the inner peripheral side of the tubular member 10.

[0068] As a result, by applying force to the radially outward direction of the tubular member 10 while pinching the end of the outer piece 11a of the laminated portion 11 with the fingers, it is possible to apply force to the outer piece 11a from any point between the end (CB) of the inner thick portion 11b1 of the vertical seal portion 11c on the side of the vertical seal portion 11c and the end (B) of the inner thick portion 11b1 on the side opposite to the vertical seal portion 11c, without causing any opening defects. Since it is possible to reliably rupture the portion between the end (CB) of the vertical seal portion 11c on the inner thick portion 11b1 side and any point on the inner piece 11b side, or the portion between the end (CA) of the vertical seal portion 11c on the outer thick portion 11a1 side and any point on the inner piece 11b side that faces the end (A) of the outer thick portion 11a1 on the opposite side to the vertical seal portion 11c side, it becomes possible to easily remove the contents from the tubular member 10.

[0069] It is also preferable that, with the contents filled on the inner periphery of the tubular member 10, a heat sterilization treatment is carried out at a temperature of 80°C or higher and 150°C or lower, a pressure of 0 MPa or higher and 0.4 MPa or lower (gauge pressure), and a time of 1 minute or higher and 60 minutes or lower.

[0070] As a result, even in the case of tubular member 10 after retort heat sterilization, by pinching the end of outer piece 11a of laminated portion 11 with the fingers and applying force to the outside in the radial direction of tubular member 10, it is possible to open tubular member 10 from any point between end (CB) on the inner thick portion 11b1 side of vertical seal portion 11c to end (B) on the opposite side to vertical seal portion 11c of inner thick portion 11b1, and from end (CA) on the outer thick portion 11a1 side of vertical seal portion 11c to end (B) on the vertical seal portion 11c side of outer thick portion 11a1. It is possible to reliably tear the portion between the end (CB) on the inner thick portion 11b1 side of the vertical seal portion 11c and any point on the outer piece 11a side facing the end (A) on the opposite side, or the portion between the end (CB) on the inner thick portion 11b1 side of the vertical seal portion 11c to the end (B) on the opposite side of the vertical seal portion 11c of the inner thick portion 11b1 and any point on the inner piece 11b side facing the end (A) on the opposite side of the vertical seal portion 11c of the outer thick portion 11a1.

[0071] Furthermore, it is preferable that the distance (AB) from the end (A) opposite the vertical seal portion 11c side of the outer thick portion 11a1 in the outer piece 11a of the laminated portion 11 to the end (B) opposite the vertical seal portion 11c side of the inner thick portion 11b1 in the inner piece 11b is 200 μm or more and 800 μm or less.

[0072] This ensures that the outer piece 11a and the inner piece 11b are securely joined together at the vertical seal portion 11c, and when removing the contents, it is possible to move the contents from any point between the end (CB) of the vertical seal portion 11c on the inner thick portion 11b1 side to the end (B) of the inner thick portion 11b1 on the opposite side to the vertical seal portion 11c side in the direction from the end (CA) of the vertical seal portion 11c on the outer thick portion 11a1 side to the end (A) of the outer thick portion 11a1 on the opposite side to the vertical seal portion 11c side. It is possible to reliably break the portion between the end (CB) of the vertical seal portion 11c on the inner thick portion 11b1 side and any point on the outer piece 11a facing it, or the portion between the end (CA) of the vertical seal portion 11c on the outer thick portion 11a1 side and any point on the inner piece 11b facing the end (A) of the outer thick portion 11a1 on the opposite side of the vertical seal portion 11c.

[0073] Furthermore, it is preferable that the cylindrical member 10 is formed into a cylindrical shape by one vertical seal portion 11c.

[0074] This allows the width dimension of the laminated portion 11 to be smaller than that of a tubular member having a plurality of seal portions formed therein, and thus makes it possible to reduce the amount of resin film used.

[0075] The resin film is preferably a heat-shrinkable film containing polyvinylidene chloride.

[0076] This makes it possible to make the tubular member 10 adhere closely to the contents by shrinking the resin film during the heat sterilization process, thereby improving the appearance of the tubular packaging body 1.

[0077] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0078] In the cylindrical packaging body 1 shown in Figures 1 to 3, fish sausage or cheese kamaboko was filled into the cylindrical member 10 as the contents, and a test was conducted to measure the incidence of opening defects relative to the ratio Do / Di. The results are shown in Tables 1 to 3.

[0079] The tubular packaging body 1 of the present invention is easy to open, and an opening test was conducted in which the end (external ear portion) of the outer piece 11a of the laminated portion 11 was pinched with fingers and the vertical seal portion 11c was peeled off, and the occurrence rate of opening defects was calculated by evaluating the opened state.

[0080] An opening test for calculating the incidence of defective opening after retort heat sterilization of the cylindrical packaging body 1 of the present invention was carried out and evaluated according to the following method.

[0081] That is, for five tubular packaging bodies 1 per subject, 10 subjects pinched the end (external ear portion) of the outer piece 11a of the laminated portion 11 of each tubular packaging body 1 with their fingers, pulled off the vertical seal portion 11c, and then opened the tubular packaging body 1 without being able to reliably break it as in the present invention, and the incidence of defective opening was calculated.

[0082] Here, defective opening in the sensory test refers to a state in which the package is opened with a portion of the film of the outer piece 11a or the inner piece 11b remaining at the end of the film at the broken portion beyond the vertical seal portion 11c after opening (a state in which the appearance of the film at the end of the broken portion is poor).

[0083] Table 1 shows the test results for Examples 1 to 11 and Comparative Examples 1 to 4, each having a different ratio Do / Di, immediately after the cylindrical member 10 was filled with the contents. The ratio Do / Di in Example 1 is 0.10, the ratio Do / Di in Example 2 is 0.45, the ratio Do / Di in Example 3 is 0.52, the ratio Do / Di in Example 4 is 0.58, the ratio Do / Di in Example 5 is 0.67, the ratio Do / Di in Example 6 is 0.91, the ratio Do / Di in Example 7 is 1.08, the ratio Do / Di in Example 8 is 0.53, the ratio Do / Di in Example 9 is 0.71, the ratio Do / Di in Example 10 is 1.07, the ratio Do / Di in Example 11 is 1.08, the ratio Do / Di in Comparative Example 1 is 1.15, the ratio Do / Di in Comparative Example 2 is 1.86, the ratio Do / Di in Comparative Example 3 is 1.24, and the ratio Do / Di in Comparative Example 4 is 1.55.

[0084] Table 2 shows the test results for Examples 12 to 16 and Comparative Example 5, each having a different Do / Di ratio, after the contents were filled into the cylindrical member 10 and subjected to boiling heat sterilization. The Do / Di ratio for Example 12 was 1.03, the Do / Di ratio for Example 13 was 1.06, the Do / Di ratio for Example 14 was 0.36, the Do / Di ratio for Example 15 was 0.86, the Do / Di ratio for Example 16 was 0.92, and the Do / Di ratio for Comparative Example 5 was 1.20.

[0085] Here, the boiling heat sterilization treatment of the tubular packaging body 1 was carried out by leaving the tubular packaging body 1 to stand in an environment at a temperature of 80°C or higher and 100°C or lower and a pressure of 0 MPa (gauge pressure) for a period of 30 minutes to 60 minutes.

[0086] Table 3 shows the test results for Examples 17 to 30 and Comparative Examples 6 to 9, each having a different Do / Di ratio, after the cylindrical member 10 was filled with contents and subjected to retort heat sterilization. The Do / Di ratio for Example 17 was 0.10, the Do / Di ratio for Example 18 was 0.35, the Do / Di ratio for Example 19 was 0.50, the Do / Di ratio for Example 20 was 0.59, the Do / Di ratio for Example 21 was 0.78, the Do / Di ratio for Example 22 was 0.85, the Do / Di ratio for Example 23 was 0.67, the Do / Di ratio for Example 24 was 1.10, and the Do / Di ratio for Example 25 was 0.80. The ratio Do / Di of Example 26 is 0.63, the ratio Do / Di of Example 27 is 0.71, the ratio Do / Di of Example 28 is 0.90, the ratio Do / Di of Example 29 is 0.96, the ratio Do / Di of Example 30 is 0.80, the ratio Do / Di of Comparative Example 6 is 1.12, the ratio Do / Di of Comparative Example 7 is 1.34, the ratio Do / Di of Comparative Example 8 is 1.16, and the ratio Do / Di of Comparative Example 9 is 1.43.

[0087] Here, the retort heat sterilization treatment of the tubular packaging body 1 was carried out using an RCS type retort sterilizer Flavor Ace-60 / 10TG manufactured by Hisaka Works, Ltd., by leaving the tubular packaging body 1 to stand in a retort oven at a temperature of 100°C or higher and 150°C or lower and a pressure of 0 MPa or higher and 0.4 MPa or lower (gauge pressure) for a time period of 5 minutes or higher and 60 minutes or lower.

[0088]

[0089]

[0090]

[0091] As shown in Table 1, the incidence of defective opening was 13.3% or more in Comparative Examples 1 to 4. On the other hand, the incidence of defective opening was 0.0% in Examples 1 to 11. That is, it was confirmed that, as in the present embodiment, immediately after filling the cylindrical member 10 with contents, regardless of the type of contents, the ratio Do / Di is preferably greater than 0 and less than or equal to 1.14, and more preferably greater than or equal to 0.10 and less than or equal to 1.08.

[0092] Furthermore, as shown in Table 2, the incidence of defective opening was 14% in Comparative Example 5. On the other hand, the incidence of defective opening was 0.0% in Examples 12 to 16. That is, it was confirmed that after the contents are filled into the tubular member 10 and subjected to boiling heat sterilization treatment, as in the present embodiment, the ratio Do / Di is preferably greater than 0 and not greater than 1.19, and more preferably 0.36 or greater and 1.06 or less.

[0093] Furthermore, as shown in Table 3, the incidence of defective opening was 13.3% or more in Comparative Examples 6 to 9. On the other hand, the incidence of defective opening was 0.0% in Examples 17 to 30. That is, it was confirmed that after filling the cylindrical member 10 with contents and performing retort heat sterilization treatment as in the present embodiment, regardless of the type of contents, the ratio Do / Di is preferably greater than 0 and less than or equal to 1.11, and more preferably greater than or equal to 0.10 and less than or equal to 1.10.

[0094] 1 Cylindrical packaging body 10 Cylindrical member 10a Base film 11 Laminated portion 11a Outer piece 11a1 Outer thick portion 11b Inner piece 11b1 Inner thick portion 11c Vertical seal portion 20 Clip A End of outer thick portion opposite to vertical seal portion B End of inner thick portion opposite to vertical seal portion CA End of vertical seal portion on outer thick portion side CB End of vertical seal portion on inner thick portion side

Claims

1. A cylindrical packaging body comprising a cylindrical member formed by shaping a resin film into a cylindrical shape, wherein the cylindrical member has a laminated portion formed by laminating strip-shaped resin films such that one end of the resin film in the width direction is positioned radially outward and the other end is positioned radially inward, the laminated portion having an outer piece positioned radially outward and an inner piece positioned radially inward, the outer piece and the inner piece having a vertical seal formed by joining portions of each other along the length of the cylindrical member, the outer piece having an outer thick portion formed in a portion of the resin film on the base film side of the vertical seal that is formed to have a thickness dimension (radially) greater than other portions closest to the end of the vertical seal, and the inner piece having an inner thick portion formed in a portion of the resin film on the base film side of the vertical seal that is formed to have a thickness dimension (radially) greater than other portions closest to the end of the vertical seal, A cylindrical packaging body in which the ratio Do / Di of the distance Do from the end of the vertical seal portion of the outer piece on the outer thick portion side to the end of the outer thick portion on the opposite side to the vertical seal portion side to the distance Di from the end of the vertical seal portion of the inner piece on the inner thick portion side to the end of the inner thick portion on the opposite side to the vertical seal portion side is greater than 0 and 1.11 or less when the contents are filled on the inner side of the cylindrical member.

2. The cylindrical packaging body according to claim 1, wherein the contents are filled inside the cylindrical member and subjected to a heat sterilization treatment at a temperature of 80°C to 150°C, a pressure of 0.0 MPa to 0.4 MPa (gauge pressure), and a time of 1 minute to 60 minutes.

3. A cylindrical packaging body as described in claim 1, wherein the distance from the end of the outer thick portion of the outer piece opposite the vertical seal portion to the end of the inner thick portion of the inner piece opposite the vertical seal portion in the laminated portion is 200 μm or more and 800 μm or less.

4. The cylindrical packaging body according to claim 1, wherein the cylindrical member is formed into a cylindrical shape by a single vertical seal.

5. The cylindrical packaging body according to claim 1, wherein the resin film is a heat-shrinkable film containing polyvinylidene chloride.

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