JPH068028Y2 - Easy-open packaging bag - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) The present invention relates to an easy-open packaging bag suitable for packaging liquids, viscous substances, and the like. Boeing phenomenon that occurs during manufacturing (for example, Japanese Patent Publication No. 37-1588 and Japanese Patent Laid-Open No. 54-73873).
The effect of (see Japanese Patent Laid-Open Publication) is advantageously reduced to make it extremely easy to open the packaging bag.

(Prior Art) A film laminated structure comprising a biaxially stretched film layer and a sealant layer laminated on the biaxially stretched film layer is folded back from the center portion in the width direction, and is produced by heat sealing the sealant layer. Generally, the packaging bag formed as a bag has a single notch-shaped or V-shaped notch in the heat-sealing portion on the required side in order to ensure the ease of opening the packaging bag. The opening of the bag is performed by tearing the bag by applying an external force directed to the front side and the back side of the bag on each of the left and right or up and down sides of the notch as boundaries. .

(Problems to be solved by the invention) By the way, in many cases, in a biaxially stretched film, due to the bowing phenomenon at the time of production, the molecular orientation direction is, for example, as shown by the solid line in FIG. Since the center portion and the side end portions in the width direction have anisotropy, one side end portion of the biaxially stretched film at the time of production is cut and used as shown by a broken line in the figure. In that case, a film laminated structure comprising such a biaxially stretched film layer and a sealant layer is folded in two in the width direction to form a bag, whereby the molecular orientation direction of the biaxially stretched film layer is On the front side of the bag, a downward-sloping curve shown by a thin line in FIG. 3 is obtained, while on the back side of the bag, a downward-sloping curve shown by a dashed line in the figure is obtained. In addition, the heat-sea In the case of a packaging bag having only a −-shaped or V-shaped tear notch in the opening portion, the action direction of the external force at the time of opening is as shown in FIG. 3 (a). In, when the molecular orientation lines of the biaxially stretched film layers on the front and back surfaces are in the directions crossing each other, that is, the back surface side alignment line shown by the alternate long and short dash line, to the front surface side, and the front surface side alignment line shown by the thin line is When each is pulled to the back side, the sealant layer located between the front and back biaxially stretched film layers receives an external force in the direction of being sheared by the front and back molecular orientation lines, so that the sealant layer has a molecular orientation direction. Relatively easy cutting, unaffected
In other words, the bag is opened under the action of a small external force, while the action direction of the external force is shown in Fig. 3 (b).
As shown in, the molecular orientation lines on both the front and back surfaces are in the direction away from each other, and the back surface side alignment line shown by the one-dot chain line is on the back surface side,
When the surface side alignment lines shown by thin lines are respectively pulled to the front side, the sealant layer between the biaxially stretched film layers receives an external force in the direction of peeling from the biaxially stretched film layer, and the sealant layer Since a large elongation deformation occurs in the bag, the tear resistance of the bag becomes extremely large, and there is a problem that a considerably large force is required to open the bag.

This invention advantageously solves the above-mentioned problems of the prior art, and suppresses the bowing phenomenon in the production of a biaxially stretched film, and hence the influence of anisotropy of molecular orientation caused by the bowing phenomenon. It is an object of the present invention to provide an easy-open packaging bag that is sufficiently reduced to make it extremely easy to open the packaging bag.

(Means for Solving the Problem) The easily openable packaging bag of the present invention comprises a biaxially stretched film layer,
A film laminated structure comprising a sealant layer laminated on the biaxially stretched film layer, in a folded posture from the center in the width direction thereof, is formed into a bag by heat sealing the sealant layer, and a predetermined heat seal portion is formed. A packaging bag provided with a tear notch at an opening position, wherein two heat-sealing portions are diagonally opposed to at least one L-shaped continuous corner portion with a bending point of the heat-sealing portion separated. In addition to providing the tear notch, the packaging space of the packaged object is made to extend narrower than the line segment connecting the two tear notches, and the line segment connecting the two notches is wrapped. Almost the same as the molecular orientation direction of the biaxially stretched film layer on either side of the bag, and substantially orthogonal to the molecular orientation direction of the biaxially stretched film layer located on the opposite side of the packaging bag from the above. You It has been extended in the direction.

(Operation) This invention is based on the finding that the sealant layer laminated on the biaxially stretched film layer has a relatively small shear resistance against tearing in any direction of the molecular orientation direction and the direction orthogonal thereto, and Its relatively low shear resistance is
It was made based on the finding that it is sufficiently maintained within an angle range of less than 15 degrees with respect to each of the molecular orientation direction and the direction orthogonal thereto, and in the easily openable packaging bag of the present invention, In particular, the extending direction of the two notches provided diagonally opposite each other at the corners is the same as the molecular orientation direction of the biaxially stretched film layer on either the front or back side of the packaging bag. On the other side of the bag, by making the direction substantially orthogonal to the molecular orientation direction, with the part where the notch is formed as a boundary, pinch each of the inner and outer parts with the left and right fingers. , For example, by twisting the outer part in either direction, the shearing of the sealant layer from the tear notch forming part proceeds smoothly from both tear notches under the action of a small twisting force, In a bag So that the sealing is very easily done.

Moreover, here, by making the packaging space of the packaged object narrower than the line segment connecting the two tear notches to the outside, the required tear length of the bag is made sufficiently short to open it. By making it easier, it is possible to effectively eliminate the risk of diffusion of liquids, viscous substances, and the like as the objects to be packaged when opening the bag.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the present invention, and FIG.
(a) is a plan view of a packaging bag, FIG. 1 (b) is a plan view of a film laminated structure, and FIG. 1 (c) is a cross-sectional view taken along the line cc of FIG. 1 (b).

In this example, a biaxially stretched film layer as the base material,
For example, a film laminated structure 4 is formed by sequentially laminating a polyethylene layer 2 as an intermediate layer and a sealant layer such as an ethylene-vinyl acetate copolymer layer 3 on a biaxially stretched nylon film layer 1, and the film laminated structure is formed. 4 from the central portion in the width direction, as shown by the arrow A in FIG. 1 (c), folded back in a direction in which the ethylene-vinyl acetate copolymer layers 3 face each other, and in such a state, the ethylene-vinyl acetate copolymer layers 3 are By heat-sealing the copolymer layers 3 to each other to form a bag, a packaging bag 5 heat-sealed in three directions is formed as shown in FIG. 1 (a).

Here, this packaging bag 5 has at least one L-shaped continuous corner portion of the U-shaped heat-sealing portion 6 shown by diagonal lines in the figure, here one corner portion with a slightly wider heat-sealing width. In addition to having two −-shaped tear notches 7 that are diagonally opposed to each other with the bending point of the heat seal portion 6 interposed therebetween,
There is a packaging space 8 for the article to be packaged, which extends narrower to the outside than a line segment connecting both of the notches 7. The end of the packaging space 8 is hermetically sealed by the heat seal portion 6.

In such a packaging bag 5, when the biaxially stretched nylon film layer 1 has a leftward downward molecular orientation direction as exemplified by a thin line 9 in FIG. The direction of molecular orientation on the back surface side of the packaging bag 5 formed as described above is a downward-sloping curve as shown by the chain line 10 in FIG. 1 (a).

Therefore, here, both the notches 7, and by extension, the extending direction of the line segment connecting them are sufficiently close to the extending direction of the thin wire 9, and the orthogonal curve to each one-dot chain line 10 is also sufficiently By making them close to each other, easiness of unsealing is ensured regardless of the acting direction of the external force with respect to unsealing from any of the tear notches 7.

In addition, here, a sufficient close state of the extending direction of the notch 7 and the thin line 9 or the curve orthogonal to the alternate long and short dash line 10 means that the extended lines of the two do not intersect with each other,
It also includes the condition that the intersection angle is less than 15 degrees. This is based on the fact that it has been confirmed that the easiness of opening the packaging bag can be sufficiently ensured when the intersection angle is less than 15 degrees. For example, it is laminated on the biaxially stretched nylon film 1. The unstretched ethyl-vinyl acetate copolymer layer 3, in addition to this, the polyethylene layer 2 is also subjected to the external force for tearing in either the molecular orientation direction of the biaxially stretched nylon film 1 or the direction orthogonal thereto. In addition to exhibiting a relatively small shear resistance, when the direction of the line segment connecting the tear notches 7 is not significantly deviated from the above two directions, empirically, the line segment connecting the tear notches 7 and the thin line 9 are used. And each dashed line 10
If the angle of intersection with each of the line segments orthogonal to is less than 15 degrees, the inner part of the line segment that connects the notch 7 with one finger and the packaging space from that line segment with the other finger. The outer parts of 8 are pinched as shown by the phantom lines in the figure, and by twisting the other with respect to one of them,
Tearing of the bag from each of the tearing notches 7, in other words, opening of the bag can be performed extremely smoothly with a small external force.

By the way, in opening the bag in this way, if the object to be packaged is a liquid, a viscous substance, etc., the object to be packaged that has entered the packaging space 8 is preliminarily rejected therefrom, and It is preferable to start the unsealing operation in a state where the re-entry is sufficiently prevented by the finger, and this makes it possible to almost certainly prevent the non-side scattering of the packaged object.

(Effect of the Invention) Thus, according to the present invention, in particular, at least one corner of the heat seal portion that is continuous in an L shape is diagonally opposed to each other with the bending point of the heat seal portion separated. Of the notch, the line segment connecting the two notches, in the same direction as the molecular orientation of the biaxially stretched film layer on either side of the packaging bag, and the packaging bag , By extending in a direction substantially orthogonal to the molecular orientation direction of the biaxially stretched film layer located on the opposite side to the above,
The relative anisotropy of molecular orientation due to the bowing phenomenon during the production of biaxially stretched film is almost eliminated by providing a relative torsional displacement on the inside and outside of the notch of the packaging bag by the action of a slight force. Without being affected, the packaging bag can be opened very easily and smoothly by the progress of the tears from both tear notches.

[Brief description of drawings]

 FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram illustrating anisotropy of molecular orientation, and FIG. 3 is a diagram showing an opening mode of a conventional packaging bag. DESCRIPTION OF SYMBOLS 1 ... Biaxially-stretched nylon film layer 2 ... Polyethylene layer 3 ... Ethylene-vinyl acetate copolymer layer 4 ... Film laminated structure 5 ... Packaging bag 6 ... Heat seal part 7 ... Cleaving notch 8 ... Packaging space

Claims (1)

[Scope of utility model registration request] 1. A heat-seal of a sealant layer, wherein a film laminate structure comprising a biaxially stretched film layer and a sealant layer laminated on the biaxially stretched film layer is folded back from the center in the width direction thereof. In a packaging bag which is made by means of a bag and is provided with a tear notch at a predetermined opening position of the heat-sealing portion, at least one L-shaped continuous corner of the heat-sealing portion is provided with the heat-sealing portion. Two tearing notches that are diagonally opposed to each other at a bending point are provided, and the packaging space of the packaged object is thinly extended to the outside of a line segment connecting the two tearing notches, and two A line segment connecting the individual notches is located in substantially the same direction as the molecular orientation direction of the biaxially stretched film layer on either side of the packaging bag, and is located on the opposite side of the packaging bag from the above. Biaxial stretching An easy-open packaging bag that extends in a direction substantially orthogonal to the molecular orientation direction of the film layer.