JP2004074541A - Packaging film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging film which can secure airtightness between a tapered pour-out nozzle etc. and a packaging bag, and excellent gas-barrier properties, in the insertion of the pour-out nozzle etc. into the packaging bag. <P>SOLUTION: This packaging film, which is constituted by laminating a thermoplastic film of three layers, is equipped with a surface layer 1 and an unoriented sealant layer 2. An unoriented ethylene-vinyl alcohol copolymer film 3 is laminated on an intermediate layer. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a packaging film which is formed by laminating a plurality of layers of a thermoplastic film and has a surface layer and an unstretched sealant layer, and which is suitable for use in making flexible packaging bags. When the injection nozzle, straw, etc. is directly pierced into a soft packaging bag for the purpose of pouring or sucking out the packaged object, the injection bag etc. are held firmly with the packaging bag itself, and It is an object of the present invention to provide a technique for ensuring excellent airtightness between an outlet nozzle or the like and a packaging bag and effectively preventing outside air from entering the packaging bag.
[0002]
[Prior art]
The tape is tapered on the packaging bag itself to pour out or suck out the packaged material, such as liquid, viscous material, powdery granular material, etc. from the soft packaging bag which is mainly used for eating and drinking. The injection nozzle and straw are directly pierced, and the injection nozzle is not accidentally slipped into or out of the packaging bag based on the elastic shrinkage of the unstretched plastic film layer that forms part of the packaging bag. For example, Japanese Patent Application Laid-Open No. 08-119296 discloses a conventional technique.
[0003]
[Problems to be solved by the invention]
By the way, when all the items to be packaged are poured out within a relatively short date and time of about 1 to 2 days by an ejection nozzle or the like pierced into the packaging bag, the unstretched plastic of the packaging bag as described above is used. The film layer prevents the dispensing nozzles and other parts from accidentally displacing the dispensing nozzles and other parts from the tilting of the packaging bag for discharging the packaged object to the return of the packaging bag to the upright position. The desired function can be sufficiently exhibited by exerting the elastic holding force to the extent possible.
[0004]
However, if it takes a longer time to exhaust the packaged material, the airtightness between the spout nozzle and the packaging bag into which it is pierced is increased, and the It is necessary to prevent oxidation due to outside air, reduction in the flavor of the packaged object, and the like.
Accordingly, the present invention provides an airtight seal between a nozzle and the like and a packaging bag, for example, when a tapered pouring nozzle or the like provided on a check valve for extraction is inserted into a packaging bag filled with an article to be packaged. Provided is a packaging film capable of sufficiently improving the properties and ensuring excellent gas barrier properties.
[0005]
[Means for Solving the Problems]
The packaging film according to the present invention is obtained by laminating a plurality of thermoplastic films, and includes a surface layer and a non-stretched sealant layer, and a non-stretched ethylene-vinyl alcohol copolymer in the intermediate layer. (Hereinafter referred to as “EVOH”).
[0006]
In this packaging film, a packaging bag can be made by fusing the unstretched sealant layers in mutually facing postures to each other by a sealing method such as heat sealing or impulse sealing. For example, when a packaged bag filled with a packaging bag is poured out, for example, when a tapered discharging nozzle provided on a check valve is pierced into the packaging bag, a non-stretched material including a sealant layer and an EVOH film is used. The film layer can firmly hold the pouring nozzle by its own elastic restoring force. In particular, under the action of the EVOH film, the holding force is further increased, and the gap between the pouring nozzle and the packaging film is increased. Excellent airtightness can be provided.
[0007]
Therefore, even if it takes days before the packaged items in the bag are used up, it is possible to sufficiently prevent the invasion of the outside air into the bag with a high gas barrier property inherent to the EVOH film, even if it takes days. Therefore, it is possible to effectively remove the risk of oxidation, flavor reduction, and the like of the packaged object in the bag.
[0008]
Here, when all the thermoplastic plastic films are unstretched films and the entire packaging film is a laminated structure of the unstretched films, the injection nozzle or the like is pierced into the packaging bag, and each of the unstretched films is inserted into the packaging bag. The spout nozzle and the like can be kept airtight with a large force under the stretch elasticity inherent to the stretched film.
[0009]
By the way, the surface layer of the packaging film may be a biaxially stretched base film layer. In this case, the so-called stiffness of the packaging bag can be enhanced while imparting various excellent barrier properties to the surface layer. However, if the surface layer is firmly bonded to the unstretched sealant layer, etc., cracks generated in the surface layer due to piercing of the injection nozzle etc. into the packaging bag can easily propagate to the unstretched sealant layer, etc. The airtightness of the bag, that is, the holding of the nozzle by the non-stretched film layer and the airtightness between the piercing nozzle and the like and the packaging bag cannot be ensured.
[0010]
Therefore, in this case, the unstretched film layer including the EVOH film can be separated from the surface layer composed of the biaxially stretched base film over a required range at a portion corresponding to the piercing position of the pouring nozzle or the like. .
[0011]
With this configuration, even if a crack occurs in the surface layer due to the piercing of the ejection nozzle or the like into the packaging bag, the unstretched film layer at the piercing position of the nozzle or the like is based on the piercing of the nozzle or the like. Since it is easily separated from the surface layer, the propagation of cracks in the surface layer to the unstretched film layer can be effectively prevented. Moreover, here, the unstretched film layer after being separated from the surface layer performs its original elastic extension based on the subsequent piercing action of the pouring nozzle or the like, and after the pouring nozzle or the like penetrates there, Since the nozzle or the like is strongly held by its own elastic restoring force, the same nozzle holding force and airtightness as described above can be provided.
[0012]
In addition, the separation of the unstretched film layer from the surface layer is performed by extrusion lamination, by omitting the application of the anchor cord agent to a specific area of the surface layer, and by dry laminating, by applying to the specific area of the surface layer. By omitting the application of the adhesive or the like, it can be performed as expected, but more preferably, silicone or cyclized rubber (Polystar) is provided between the surface layer and the unstretched film layer including the EVOH film. Release agent) and a release agent such as paraffin.
[0013]
According to this, under the action of a peeling agent such as silicone, the non-stretched film layer can be more easily and reliably drawn in the intended range when the injection nozzle is pierced with the surface layer. Peeling from the film layer can be realized.
[0014]
In addition, when the unstretched film layer separated from the surface layer in this way is constituted by three or more films sandwiching the EVOH film between the intermediate layers, more excellent moisture proofness is realized together with the gas barrier property. can do.
[0015]
Further, another packaging film according to the present invention is obtained by laminating a plurality of thermoplastic films, and includes, for example, a surface layer that can be a biaxially stretched base film layer and a non-stretched sealant layer. The unstretched sealant layer is formed by bonding a single-layer or laminated unstretched film having a required flat rim shape, including an EVOH film, to the peripheral portion thereof with an adhesive or by fusion. .
According to this, by letting a pouring nozzle or the like penetrate through a separately attached single-layer or laminated unstretched film, the unstretched film can exhibit the expected nozzle holding power and airtightness. . Here, more preferably, the non-stretched film is composed of three or more films sandwiching an EVOH film between intermediate layers. With such a configuration, the low moisture-proof property of the EVOH film can be effectively compensated for by using another film, and excellent moisture-proof properties can be imparted to the laminated unstretched film itself.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a packaging film according to the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is an enlarged cross-sectional view showing an embodiment of the present invention. This is a package in which a surface layer, a sealant layer, and an intermediate layer are formed of unstretched thermoplastic films 1, 2, and 3, respectively. 1 shows a laminated structure of a film for use, in which an unstretched plastic film 3 as an intermediate layer is formed of an EVOH film having poor heat sealability.
The packaging film 4 having such a laminated structure can be formed into a packaging bag of a required form by various known sealing methods.
[0018]
For example, the packaging film 4 having such a laminated structure is folded at the center in the longitudinal direction with the sealant layer inside, and both sides of the packaging film 4 are hatched in FIG. 2A. To form respective side seal portions 5 by heat sealing. By forming a side seal type packaging bag 6 having a folded portion as a bottom as a basic form, and forming a heat seal portion having a substantially triangular shape in a plan view on each side of the bottom of the packaging bag 6, FIG. A self-supporting type square bottom packaging bag 7 as shown in a perspective view can be provided.
[0019]
Here, as shown in FIG. 2 (b), the heat seal portion of the bottom of the packaging bag 7, which has a substantially triangular shape, connects the bottom 8 of the side seal type packaging bag 6 from the lower end of each side seal portion 5. The triangular portion 9 of the bottom 8 formed by taking a somewhat raised bottom position can be formed by heat sealing the side portion of the packaging bag 6 as shown by hatching in the figure. The triangular heat seal portion 10 thus formed is bent outward by 90 ° as shown by the arrow in the figure, thereby realizing the self-standing square bottom packaging bag 7 as shown in FIG.
[0020]
As described above, this square bottom packaging bag 7 becomes a self-standing packaging bag under an extremely simple structure, and particularly, because of the presence of the square bottom bottom, is a basic form of the same, as shown in FIG. Compared to the side-sealable packaging bag 6 having dimensions, a larger amount of items to be packed can be filled, and the bag opening can be reliably sealed by heat sealing. In other words, the side-sealed packaging bag 6 shown in FIG. 2A has a tendency that the front and rear film portions approach or contact each other in its normal state. In sealing the bag opening, the packaged object overflows from the opening.
[0021]
FIG. 4 is a view showing this fact. When the packaging bag 7 is filled with a liquid or other objects to be packaged, the packaging bag 7 is deformed based on a large bulging deformation in the front-rear direction, particularly in the vicinity of the bottom. Even if a large amount of items to be packed are filled, the elastic restoring force in the crushing direction of the packaging bag itself is advantageously suppressed, so that the bag opening can be reliably sealed.
[0022]
FIG. 5 shows a packing bag 11 as described above in which a packing object is filled and packed, in a columnar box, preferably a paper box 12 having almost the same height as the packing bag 11, under the deformation of the packing bag 11. It is a perspective view which shows the packaging structure which will be in the state which was almost fully stored.
In this packaging structure, the filling and packaging bag 11 is sufficiently protected and shielded from light by the paper box 12, and is given a stable self-standing posture by the paper box 12, and is provided with Under the support of weight and the like, the shape is forcibly specified.
Therefore, even if the packaging bag is thinned, unexpected leakage of the packaged object can be sufficiently prevented, and in addition to the efficiency of storage and transportation of the packaged item, display of the packaged item, etc. In this case, the space efficiency can be greatly improved.
[0023]
More preferably, in such a packaging structure, each of the substantially triangular heat seal portions 10 at the bottom of the filling and packaging bag 11 is connected to the top or bottom lid of the paper box 12, and the respective side portions overlapping the bottom lid 13 in the figure. The tongue piece 14 is bonded to the inner surface. In this case, bonding of the heat seal portion 10 is performed by fusing the heat seal portion 10 by impulse seal, high frequency seal, heat seal, or the like. There are advantages. Incidentally, this fusion of the heat seal portion 10 can be performed not only directly on the paper surface of the side tongue piece 14, but also on a plastic layer coated thereon, for example, a polyolefin resin layer.
[0024]
Here, since the packaging film 4 constituting the square bottom packaging bag 7 is formed only of a non-stretched plastic film having a laminated structure, the side tongue pieces 14 of the triangular heat seal portion 10 of the filling packaging bag 11 are formed. The fusing to can be easily performed on the basis of its relatively low temperature melting.
[0025]
By the way, under such a packaging structure, an object to be packaged has a substantially conical tapered end portion at, for example, the bottom portion 15 of the filled packaging bag 11 stored in the paper box 12, as illustrated in FIG. The dispensing nozzle 16 or the straw 17 can be pierced under the elongation deformation in the elastic region of the packaging film itself to discharge and suck out the article to be packaged. Such stabbing is performed in a triangular shape, and the side tongue piece 14 of the paper box 12 to which the heat seal portion 10 is joined is set to a completely open position as shown in FIG. It is preferable to perform the operation with a slight tension applied to the bottom portion 15 in order to achieve a smooth and secure piercing to a required position.
[0026]
After the injection nozzle 16 and the like are stabbed in this manner, the bottom 15 of the filling and wrapping bag 11 made of a non-stretched film has its own elastic restoring force around the injection nozzle 16 and the like penetrating therethrough. In addition to providing sufficient air-tightness and liquid-tightness based on the airtightness, and exhibiting sufficient holding power to nozzles and the like, and further, under the action of the EVOH film, providing excellent gas barrier properties, More effectively prevent intrusion into the packaging bag.
Therefore, in pouring the packaged object through the pouring nozzle 16 or the like, the paper box 12 is tilted to prevent unexpected displacement of the pouring nozzle 16 or the like. Leakage of the packaged object from between the bottom 16 and the bottom portion 15 and permeation and invasion of outside air into the packaging bag can also be reliably prevented.
[0027]
In the case where such a pour of the packaged object is performed via a check valve 18 formed integrally with the pour nozzle 16 and illustrated in a longitudinal sectional view in FIG. It is possible to effectively prevent outside air from entering into the packaging bag via the pouring nozzle 16 at the start and stop of pouring accompanied by a tilting displacement.
[0028]
That is, the check valve 18 is provided in a space 23 defined by a lower member 20 forming an inlet port 19 communicating with the discharge nozzle 16 and an upper member 22 forming an outlet port 21 in a flexible manner. For example, a circular diaphragm 24 made of excellent rubber, elastomer, plastic, or the like is arranged, and a projection 25 is provided at the center of the diaphragm 24 so as to protrude downward from the center of the upper member 22 in the figure. And the peripheral portion of the diaphragm 24 is brought into contact with the lower member 20 around the inlet port 19 over its entire circumference, and the check valve 18 includes the inlet port 19 and the outlet port. When the pressure acting on each of the pressure members 21 is equal, the diaphragm 24 is, as shown in FIG. In contact with the under normal closed position closing the inlet port 19, to prevent outside air inlet from the outlet port side to the inlet port side. On the other hand, when the pressure or the force acting on the outlet port side becomes larger than that on the inlet port side, the diaphragm 24 adheres completely around the inlet port 19 under the overall deformation thereof, so that the diaphragm 24 adheres completely. In this state, the backflow of the packaged material once flowing out of the diaphragm 24 to the outlet port side into the packaging bag 11 and the invasion of the outside air into the packaging bag are completely prevented by the diaphragm 24. Become.
[0029]
By the way, when the pressure or force acting on the diaphragm 24 from the inlet port side by the tilting operation or the like of the filling / packing bag 11 exceeds that of the outlet port side, the diaphragm 24 applies the pressure or the like of the packaged object in the bag. In the range and the displacement amount according to the above, the communication between the inlet port 19 and the outlet port 21 is provided at a distance from the lower member 20, so that the object to be packaged such as liquid flowing into the space 23 from the inlet port 19 is not affected by the diaphragm. 24 can flow out of the outlet port 21 to the outside through the raised deformed portion.
[0030]
Here, when the packaged object in the filling and packaging bag is poured out in this way, the square-bottomed packaging bag itself has excellent flexibility, and the amount corresponding to the volume of the packaged product to be poured out. Since it is compressed and deformed, it is not necessary to take in outside air into the bag when it is poured out. Therefore, oxidation of the packaged object due to the invasion of outside air into the bag, contamination, flavor reduction, etc. can be more effectively achieved. Can be prevented.
[0031]
FIG. 8 is a cross-sectional view showing another embodiment of the packaging film, which is formed by forming the surface layer of the packaging film 4 with the biaxially stretched base film 26 having various barrier properties. A laminated unstretched film layer 27 containing an EVOH film is laminated on the surface layer, and a release agent 28 having a required size and shape is interposed between the surface layer and the unstretched film layer 27. It is. In this case, when the packaging film has a three-layer structure as shown in FIG. 8A, the intermediate layer is made of the EVOH film 29, and the innermost unstretched sealant layer is made to have a heat-sealing property. It is preferable to form the non-stretched film 30 which is excellent.
[0032]
When the packaging film has a four-layer structure as shown in FIG. 8B, the heat-sealable unstretched film 30 in which the non-stretched film layer 27 has the EVOH film 29 as an intermediate layer, and the like. It is preferable to have a laminated structure with the non-stretched film 31. In such a packaging film 4 including the biaxially stretched base film 26, when the surface layer and the non-stretched film layer 27 are firmly joined and laminated, the outer layer of the bottom 15 of the filled packaging bag 11 is formed. When the pouring nozzle 16 or the like is pierced into the stretched base film 26 as shown in FIG. 6, a crack generated in the stretched base film 26 thereby propagates to the non-stretched film 27 and the entire packaging film 4 Therefore, it is practically impossible for the film 4 to exhibit the above-described airtightness, nozzle holding power, and the like.
[0033]
However, as shown in FIG. 8, when a release material 28 is interposed between the surface layer made of the biaxially stretched base film 26 and the non-stretched film layer 27, the surface of the pouring nozzle 16 or the like In the piercing from the layer side, the unstretched film layer 27 can be easily and reliably separated from the surface layer by the action of the release agent 28 as shown by the imaginary line in the figure. The penetrating outflow nozzle 16, the straw 17, etc. are passed through the exfoliated portion of the non-stretched film layer 27 while extending and deforming it in the elastic region, based on the elastic contraction force of the non-stretched film layer 27, The same air-tightness, liquid-tightness, nozzle holding power, gas barrier property, and the like as described with reference to FIG. 6 can be provided.
In this case, even if the biaxially-stretched base film layer 26 has a crack, progress, or the like, the crack does not propagate to the peeled portion of the non-stretched film layer 27, so that the above-described action can be reliably exhibited. Can be fully secured.
[0034]
FIG. 9 is a cross-sectional view showing another laminated structure of the packaging film. In this figure, the surface layer is formed of the biaxially stretched base film 26, and the innermost unstretched sealant layer is formed to have a heat sealing property. When the intermediate layer is formed by the unstretched film 32 having the required physical properties, the innermost unstretched sealant layer contains the unstretched EVOH film, A single-layer or laminated non-stretched film having a shape, in the figure, an unstretched film 33 having a three-layer structure is joined at its peripheral portion by an adhesive or by heat fusion.
Here, when the unstretched film 33 has a three-layer structure as shown in the figure, it is preferable to use an EVOH film 34 as an intermediate layer in order to improve the moisture-proof property.
[0035]
According to the packaging film configured as described above, when the pouring nozzle 16 or the like is pierced from the side of the biaxially stretched base film as the surface layer, a crack or the like is generated in the stretched base film 26, and the crack is not generated. Even if the crack propagates to the stretched films 30 and 32, the propagation of the crack to the attached unstretched film 33 is sufficiently prevented by being joined to the unstretched sealant layer only at the peripheral portion. . Therefore, when the piercing of the ejection nozzle 16 or the like penetrates through the unstretched film 33 by the subsequent piercing, the unstretched film 33 moves the ejection nozzle 16 or the like with sufficient airtightness as described with reference to FIG. Holding with a sufficiently large force, and under the excellent gas barrier properties of the EVOH film 34, the invasion of outside air into the filled packaging bag 11 can be effectively prevented for a long period of time.
[0036]
【The invention's effect】
Thus, according to the present invention, in particular, based on the excellent gabarrier properties of the non-stretched EVOH film, for example, a tapered pouring nozzle or the like provided in a check valve for pouring can be replaced with a packaging bag made of the packaging film according to the present invention. When piercing into the bag, the pouring nozzle, including the check valve, is kept airtight with a sufficiently large force, effectively preventing outside air from entering the packaging bag, and oxidizing the bag. , Contamination, flavor reduction, etc. can be effectively protected.
[Brief description of the drawings]
FIG. 1 is a sectional view showing an embodiment of a packaging film.
FIG. 2 is a view showing a production example of a square bottom packaging bag.
FIG. 3 is a perspective view of a square bottom packaging bag.
FIG. 4 is a perspective view of a filling and packaging bag.
FIG. 5 is a perspective view illustrating a packaging structure using a box.
FIG. 6 is a cross-sectional view showing an example of inserting a discharge nozzle and a straw into a packaging bag.
FIG. 7 is a longitudinal sectional view showing a check valve integrated with a discharge nozzle.
FIG. 8 is a cross-sectional view showing another embodiment of the packaging film.
FIG. 9 is a sectional view showing still another embodiment of the packaging film.
[Explanation of symbols]
1,2,3,30,31,32 Unstretched film 4 Packaging film 5 Side sealing portion 6 Side sealing type packaging bag 7 Square bottom packaging bag 8 Bottom 9 Triangular portion 10 Triangular heat seal portion 11 Filling packaging Bag 12 Paper box 13 Bottom lid 14 Side tongue piece 15 Bottom 16 Discharge nozzle 17 Straw 18 Check valve 19 Inlet port 20 Lower member 21 Outlet port 22 Upper member 23 Space 24 Diaphragm 25 Projection 26 Biaxially stretched base film 27 Unstretched film layer 28 Release agent 29, 34 EVOH film 33 Unstretched fail

Claims (7)

A packaging film comprising a laminate of a plurality of thermoplastic films and having a surface layer and an unstretched sealant layer,
A packaging film in which an unstretched ethylene vinyl alcohol copolymer film is laminated on an intermediate layer. The packaging film according to claim 1, wherein all the thermoplastic films are unstretched films. The packaging film according to claim 1, wherein the surface layer is a biaxially stretched base film, and the unstretched film layer containing the ethylene vinyl alcohol copolymer film can be separated from the surface layer over a required range. The packaging film according to claim 3, wherein a release material is provided between the surface layer and an unstretched film layer containing an ethylene vinyl alcohol copolymer film. The packaging film according to claim 3 or 4, wherein the unstretched film layer separated from the surface layer is composed of three or more films sandwiching an ethylene vinyl alcohol copolymer film therebetween. A packaging film comprising a laminate of a plurality of thermoplastic films and having a surface layer and an unstretched sealant layer,
A packaging film comprising a non-stretched sealant layer and a single-layer or laminated unstretched film having a required flat ring shape including an ethylene vinyl alcohol copolymer film joined at a peripheral portion thereof. The packaging film according to claim 6, wherein the unstretched film is constituted by three or more layers of films sandwiching an ethylene vinyl alcohol copolymer film between intermediate layers.

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