JP4568981B2 - Packaging bag - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a packaging bag made of a multilayer film including an orientation resin film, which can be easily torn and opened by hand.
[0002]
[Prior art]
As a packaging material for a packaging bag, a multilayer film including an oriented resin film that has been oriented by stretching is usually used to give strength. However, a packaging bag using a packaging material made of a multilayer film in which such orientation resin films are laminated has high strength, but it is difficult to tear and open it by hand.
[0003]
Therefore, an example of the prior art for facilitating the opening of the packaging bag is described in Japanese Utility Model Publication No. 59-87445. According to the technique described in this publication, an easily cutable area is formed in a part of the film by heat-treating the film made of the thermoplastic resin. This makes it possible to easily tear the film by hand along the easily cut area.
[0004]
[Problems to be solved by the invention]
However, as shown to (A) of FIG. 3, when the easy-cut area 40 is provided in the surrounding shape in the packaging bag 4, it can open easily along the easy-cut area 40. FIG. That is, the tear 6 at the time of opening proceeds transversely within the easily cuttable area 40.
[0005]
On the other hand, as shown in FIG. 3 (B), when the easy-cut region 40 is provided along the folded portion of the packaging bag 4, the tear start portion is the easy-cut portion, but it is not separated from the easy-cut portion. It tears across the boundary of the area into an easily cut area.
[0006]
However, the strength of the packaging material changes abruptly at the boundary between the easily cuttable area and the non-easycuttable area. For this reason, it may be difficult to tear the packaging bag across this boundary. As a result, when the tear 6 that has advanced through the easy-cut region 40 of the packaging bag 4 reaches the boundary 7, there is a problem that the tear 6 tends to bend along the boundary 7 without passing through the boundary 7. . Further, as shown in FIG. 3C, there is a similar problem when the easily cutable area 40 is provided so as to protrude inward from the folded portion of the packaging bag 4 and is torn from the specific portion.
[0007]
The present invention has been made to solve the above problems, and an object of the present invention is to provide a packaging bag that is easy to tear from an arbitrary position.
[0008]
[Means for Solving the Problems]
The packaging material according to the present invention is a packaging bag formed of a packaging material including an orientation resin film, and has a temperature higher than the melting point of the orientation resin film along at least one of the folded portions of the packaging material. And a heat treatment region where the orientation of the orientation resin film is broken, and a temperature lower than the melting point at a boundary portion between the heat treatment region and the non-heat treatment region where the orientation is not broken. The heat treatment region and the buffer region have a constant irradiation intensity of the heat treatment region, and the irradiation intensity of the buffer region decreases with increasing distance from the heat treatment region. has been formed by irradiating a laser beam having a distribution, torn beyond the boundary portion to the non-heated region from an arbitrary position of the heat treatment region It is constituted to be sealed.
[0009]
Thus, in this invention, the buffer area | region is provided in the boundary part of a heat processing area | region and a non-heat processing area | region. Since the buffer region is not heated to the melting point, the orientation is not completely broken, but is partially broken. For this reason, the strength of the packaging material portion of the buffer region is higher than that of the heat treatment region and lower than that of the non-heat treatment region.
[0010]
For this reason, it is possible to prevent the strength of the packaging material from abruptly changing when tearing beyond a boundary portion from an arbitrary position in the heat treatment region of the packaging bag to the non-heat treatment region. Thereby, it can tear easily beyond a boundary part, without the direction to tear at a boundary part bending.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the packaging bag of the present invention, the packaging material forming the packaging bag , and the easy-opening processing method thereof will be described together. First, with reference to FIG. 1, the easy-opening processing method of the packaging material in embodiment is demonstrated.
[0012]
In this embodiment, as shown in FIG. 1 (A), a laser beam is irradiated to a part of the packaging material 1 including an orientation resin film by a laser irradiation device 2 while being conveyed at a speed of 12 m / second. . A carbon dioxide laser with an output of 100 to 300 W is used as the laser irradiation device 2. And after laser beam irradiation, it cools, pressing the packaging material 1 with a pair of cooling roll.
[0013]
As a result of the laser light irradiation, a part of the packaging material 1 is heated to a temperature higher than the melting point of the orientation resin film, and a heat treatment region 11 shown in FIG. In the heat treatment region 11, the orientation of the orientation resin film is broken, and the strength of the packaging material is partially reduced. For this reason, the ease of tearing is improved in the heat treatment region 11.
[0014]
Further, this laser beam has an irradiation intensity distribution shown in FIG. A curve I in FIG. 1B shows an irradiation intensity distribution in a direction orthogonal to the transport direction. As shown by the curve I, the irradiation intensity is constant in the heat treatment region, and on both sides, the irradiation intensity decreases with increasing distance from the heat treatment region.
[0015]
Therefore, as shown in FIG. 1C, the boundary between the heat treatment region 11 and the non-heat treatment region 10 is heated to a temperature lower than the melting point of the orientation resin film and higher than room temperature. For example, the buffer region 12 having a width of about 1 mm is formed. The strength of the packaging material portion of the buffer region 12 is higher than that of the heat treatment region 11 and lower than that of the non-heat treatment region 10. Also, the buffer area 12 may appear white and hazy.
[0016]
Further, in the buffer region 12, since the irradiation intensity decreases as the distance from the heat treatment region 11 increases, a temperature gradient is applied so that the heating temperature decreases as the distance from the heat treatment region 11 increases. For this reason, in the buffer area | region 11, the grade which orientation collapse | crumbles becomes small as it leaves | separates from the heat processing area | region 11. FIG. That is, the strength of the packaging material 1 increases as the distance from the heat treatment region 11 increases.
[0017]
In FIG. 1C, the boundary between the heat treatment region 11 and the buffer region 12 and the boundary between the buffer region 12 and the non-heat treatment region 10 are clearly drawn. In processed packaging, these boundaries are not always clear.
[0018]
Next, with reference to FIG. 2, the example of the packaging bag formed with the packaging material 1 easily opened as mentioned above is demonstrated. 2A to 2C show examples of a so-called pillow pouch 4a, three-way seal pouch 4b, and stick pouch 4c, respectively. And in each pouch, the heat processing area | region 11 and the buffer area | region 12 are formed along the folding | turning part 8 of a packaging material, and can be opened from the arbitrary positions of the folding | turning part 8. FIG. That is, each pouch is formed by folding back symmetrically at the center of the band-shaped heat treatment region 11 of the packaging material 1 portion shown in FIG.
[0019]
In the pillow pouch shown in FIG. 2A, the heat treatment region 11 and the buffer region 12 are provided along both folded portions 8, but they may be provided along one folded portion 8. In addition to the above configuration, a buffer region 12 and a heat treatment region 11 may be provided in the vicinity of the back pasting portion 9 from the opening direction. Further, in the stick pouch shown in FIG. 2C, the heat treatment region 11 is provided only in one folded portion 8, but the heat treatment region 11 may be provided in both folded portions. In addition, the easy-cut area 40 may be configured as shown in FIG. 3C, and the heat treatment area 11 and the buffer area 12 may be provided.
[0020]
In each pouch, a buffer region 12 is provided at a boundary portion between the heat treatment region 11 and the non-heat treatment region 10. For this reason, when tearing beyond the boundary portion from the position of the folded portion 8 where the heat treatment region 11 is provided to the non-heat treatment region 10, the strength of the packaging material gradually changes. Thereby, it is possible to easily tear the boundary portion beyond the boundary portion without bending the traveling direction of the tear 6 at the boundary portion.
[0021]
In the above-described embodiment, the example in which the present invention is configured under specific conditions has been described. However, the present invention can be variously modified. For example, in the above-described embodiment, an example of heating with laser light has been described. However, in the present invention, the heating method is not limited to laser light irradiation.
[0022]
【The invention's effect】
As described above in detail, according to the present invention, the buffer region is formed at the boundary portion between the heat treatment region and the non-heat treatment region. For this reason, when tearing beyond a boundary part from a heat treatment area | region to a non-heat-treatment area | region, it can prevent that the intensity | strength of a packaging material changes rapidly. Thereby, it can tear easily beyond a boundary part, without the direction to tear at a boundary part bending.
[Brief description of the drawings]
FIG. 1A is a diagram for explaining an easy-opening method according to an embodiment, and FIG. 1B is a graph showing an irradiation intensity distribution of laser light.
FIGS. 2A to 2C are diagrams of a packaging bag according to an embodiment. FIG.
FIGS. 3A to 3C are views of a packaging bag for explaining the related art and its problems. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Packaging material 2 Laser irradiation apparatus 3 Cooling roll 4 Packaging bag 4a Pillow pouch 4b Three-sided seal pouch 4c Stick pouch 5 Seal part 6 Rupture 7 Boundary 8 Folding part 9 Back sticking part 10 Non-heat-treatment area 11 Heat-treatment area 12 Buffer area 40 Easy-to-cut area

Claims (1)

A packaging bag formed of a packaging material containing an orientation resin film,
Along with at least one of the folded portions of the packaging material, the heat treatment is performed at a temperature higher than the melting point of the orientation resin film, and the heat treatment region in which the orientation of the orientation resin film is broken,
At the boundary portion between the heat treatment region and the non-heat treatment region where the orientation is not broken, a buffer region that is heat treated at a temperature lower than the melting point,
The heat treatment region and the buffer region are formed by irradiating laser light having an irradiation intensity distribution in which the irradiation intensity of the heat treatment region is constant and the irradiation intensity of the buffer region decreases with increasing distance from the heat treatment region. It has been
A packaging bag, which is torn and opened from an arbitrary position in the heat treatment region to the non-heat region beyond the boundary portion.

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