JP7498045B2 - Packaging Bag - Google Patents

Description

The present invention relates to a packaging bag.

Conventionally, packaging bags that are opened by tearing two sheets of packaging material made of flexible sheet-like resin have been used as packaging bags for sealing and containing liquid, granular, powdery or solid foods, medicines, etc. One type of packaging bag has a line of weakness formed along the intended opening line to make it easier to tear.

For example, Patent Document 1 discloses a packaging bag in which linear main guide lines that guide the cut are provided on both sides of the intended opening line (the opening side and the bottom side) on the front and back packaging materials, and auxiliary guide lines that are inclined in a direction that intersects with the intended opening line and merge with the main guide line are provided between the two main guide lines in a portion of the intended opening line, with the inclination directions in the opposite directions on the front and back packaging materials, so that the cut is guided from the auxiliary guide line to the main guide line. Patent Document 2 also discloses a packaging bag in which a W-shaped weak line is provided on one side of the front and back packaging materials as a weak line along the intended opening line, and an M-shaped weak line that is upside down from the W shape is provided on the packaging material on the other side.

JP 2019-123538 A JP 2007-331804 A

In the packaging bag disclosed in Patent Document 1, the auxiliary guide line leading to the main guide line is provided partially along the intended opening line, so the cut edge of the torn packaging material may cross the auxiliary guide line and become dislodged from the auxiliary guide line, making it difficult to open. In contrast, the weak line of the packaging bag disclosed in Patent Document 2 is formed over the entire length of the intended opening line, so the weak line is always torn and the cut edge coincides with the weak line. However, the shape of the weak line is complex as it is a combination of arcs and straight lines, and there is room for improvement in that it is time-consuming to form the weak line.

The present invention aims to provide a packaging bag that is easy to open because, when the packaging material is torn open, the cut is reliably guided to the line of weakness over the entire length of the intended opening line, and the line of weakness can be easily formed.

(1) The packaging bag of the present invention comprises a plurality of sheet-like packaging materials that are stacked on top of each other, a sealing section where the peripheral portions of the plurality of packaging materials are bonded to each other, a storage section that is formed between the plurality of packaging materials and is sealed by being surrounded by the sealing section, and an opening guide band that is provided on the packaging materials along a planned opening line that extends in the opening direction and is set between any two points of the sealing section, the opening guide band extending over substantially the entire length of the planned opening line and having multiple rows of weakened lines formed by half-cut grooves that are formed by removing a portion of the packaging material in the thickness direction from the surface, the weakened lines including a plurality of first straight line portions that are inclined with respect to the opening direction and a plurality of second straight line portions that are inclined in the opposite direction to the first straight line portions with respect to the opening direction, and the first straight line portions and the second straight line portions are arranged along the opening direction to form a zigzag pattern having mountain-shaped portions and valley-shaped portions.

(2) In (1), the first straight portion and the second straight portion have approximately the same length and are arranged intermittently and alternately along the opening direction, and in the opening induction band, the respective positions of the first straight portion and the second straight portion of adjacent weak line portions are approximately the same in the opening direction.
In this specification, the term "approximately" does not strictly specify a state, but rather includes a state that is approximate to the extent that the function or effect can be achieved.

(3) In (1), the weak line portion has a first weak line pattern having a substantially Z-shape in which the length of the first straight line portion is shorter than the length of the second straight line portion and one of the second straight line portions is disposed between two of the first straight line portions along the opening direction, and the first weak line patterns are alternately arranged with a phase shift in the opening direction, so that the peaks and valleys overlap in a diamond shape in a direction substantially perpendicular to the opening direction, and the first weak line patterns are spaced apart.

(4) In (3), the first weak line pattern is continuous with the first straight line portion and the second straight line portion.

(5) In (3), the first weak line pattern has the first straight line portion and the second straight line portion spaced apart.

(6) In (1), the weak line portion has a second weak line pattern in which one mountain-shaped portion and one valley-shaped portion are overlapped in a diamond shape while being spaced apart in a direction substantially perpendicular to the opening direction, and a plurality of the second weak line patterns are intermittently arranged along the opening direction, and in the opening induction band, the positions of the second weak line patterns of adjacent weak line portions are substantially the same in the opening direction.

(7) In any of (1) to (6), the mountain-shaped portion and the valley-shaped portion each form an isosceles triangle with a line along the opening direction as its base, and the angles of the corners forming the apex of the mountain-shaped portion and the corners forming the bottom of the valley-shaped portion are the same and are between 60° and 150°.

The present invention provides a packaging bag that is easy to open because the cut is reliably guided to the line of weakness along the entire length of the intended opening line when the packaging material is torn open, and the line of weakness can be easily formed.

1 is a plan view showing a packaging bag according to a first embodiment of the present invention. 4 is a diagram showing a portion of the opening guidance strip according to the first embodiment; FIG. A figure showing the cut edge formed by breaking the opening induction strip in the first embodiment. This is a diagram showing a reference example of an opening induction band in which a weak line is formed all around 11 is a plan view showing the opening end side of a packaging bag according to a second embodiment of the present invention. FIG. A diagram showing a part of the opening guidance strip according to the second embodiment. FIG. 11 is a plan view showing the opening end side of a packaging bag according to a third embodiment of the present invention. A diagram showing a part of the opening guidance strip according to the third embodiment. FIG. 11 is a plan view showing the opening end side of a packaging bag according to a fourth embodiment of the present invention. A diagram showing a part of the opening guidance strip according to the fourth embodiment.

The following describes an embodiment of the present invention with reference to the drawings.

First Embodiment
Fig. 1 is a plan view of a packaging bag 1 according to a first embodiment. The packaging bag 1 includes two overlapping packaging materials 2. Fig. 1 shows the front packaging material 2. The packaging material 2 is a sheet-like resin formed into a rectangular shape. The packaging bag 1 of this embodiment has a vertically long rectangular shape in a plan view, and the upper end in Fig. 1 is opened. The outer shape of the packaging bag 1 according to the present invention is not limited to a rectangular shape, and may be a square shape, a polygonal shape, or a shape including a curved outer line.

The packaging bag 1 has a sealing portion 4 in which the peripheral portions 3 of two sheets of packaging material 2 stacked in the thickness direction, which is the front and back direction in FIG. 1, are bonded together. The peripheral portion 3 includes a peripheral portion 3a, which is the upper end and the end on the opening side in FIG. 1, a peripheral portion 3b at the lower end parallel to the peripheral portion 3a, and peripheral portions 3c and 3d at the left and right edges parallel to each other. The bonding of the peripheral portion 3 is performed, for example, by a means such as thermal welding (heat sealing) or ultrasonic welding. Between the two sheets of packaging material 2, a storage portion 5 consisting of a space surrounded and sealed by the sealing portion 4 is formed. That is, the packaging bag 1 includes two sheets of packaging material 2 made of sheet-like resin, a sealing portion 4 in which the peripheral portions 3 of the two sheets of packaging material 2 are bonded together, and a storage portion 5 formed between the two sheets of packaging material 2 and surrounded and sealed by the sealing portion 4. The packaging bag 1 further includes an opening guide band 6, which will be described later.

The packaging material 2 is a flexible sheet made of a resin such as polyvinyl chloride, polyethylene, polypropylene, polyethylene terephthalate, or nylon (polyamide). The packaging material 2 may be a single-layer structure made of a film made of one of the above resins, or a multi-layer structure made of one or more films laminated together. In the case of a single-layer structure, the thickness of the packaging material 2 is about 20 to 100 μm, and in the case of a multi-layer structure, the thickness of the packaging material 2 is about 30 to 200 μm. The storage section 5 contains a predetermined amount of liquid, granular, powdery, or solid food or medicine. The contents are stored in the storage section 5 through the unsealed opening, with the rest of the container sealed except for the peripheral edge 3a at the end on the opening side. After this, the open peripheral edge 3a is glued and sealed, and the contents are sealed in the packaging bag 1.

As shown in Figure 1, the packaging bag 1 of this embodiment has an opening guide band 6 extending in the width direction indicated by the arrow X on the inside part close to the peripheral portion 3a of one end (upper end in Figure 1) in the longitudinal direction indicated by the arrow Y. The packaging bag 1 of this embodiment is opened by tearing the opening guide band 6, with the opening guide band 6 positioned on the upper side and held so that it extends in the horizontal direction. In the following description, based on this posture when opened, the direction of the arrow Y in Figure 1 will be referred to as the up-down direction, and the direction of the arrow X will be referred to as the left-right direction or opening direction.

The opening guide strip 6 has a certain width (vertical length) and is provided between the left and right peripheral portions 3c, 3d of the packaging material 2. A planned opening line 7 extending in the opening direction is set in the vertical center of the opening guide strip 6. In the packaging bag 1 of this embodiment, when a tearing force is applied to the two sheets of packaging material 2 along the planned opening line 7, the force is transmitted to the opening guide strip 6, which is torn and opened. When the opening guide strip 6 is broken, the packaging bag 1 is separated into a bag portion 1A below the opening guide strip 6 and a separation portion 1B above the opening guide strip 6, and the storage portion 5 is opened to the outside. The bag portion 1A comprises most of the storage portion 5.

A notch 8 is formed in each of the left and right peripheral portions 3c, 3d. The notch 8 is formed on an extension of the intended opening line 7 as a starting point for tearing. In this embodiment, the notch 8 is a V-shaped cutout. The notch may be a U-shaped cutout, a through hole that penetrates the peripheral portions 3c, 3d in the front-to-back direction, or a simple slit.

An inner fastener 9 is provided below the opening guide band 6 in the packaging bag 1, extending in the width direction between the left and right peripheral portions 3c, 3d. After the opening guide band 6 is broken and the packaging bag 1 is opened, the inner fastener 9 can be repeatedly opened and closed to repeatedly seal and open the storage section 5. Note that the inner fastener 9 is not essential for implementing the present invention, and is provided as necessary.

The opening guidance band 6 extends along the opening direction. The opening guidance band 6 has three rows of weak lines 10 extending in the opening direction. That is, the weak lines 10 are formed in three rows in the vertical direction. Each of the three rows of weak lines 10 extends over substantially the entire length of the intended opening line 7.

2, each of the weak line portions 10 includes a plurality of first straight line portions 11 and a plurality of second straight line portions 12. The plurality of first straight line portions 11 and second straight line portions 12 are arranged intermittently and alternately in the opening direction. The first straight line portions 11 and second straight line portions 12 are both half-cut grooves in which a portion of the thickness direction of the packaging material 2 is removed from the surface to a predetermined depth. As a method for forming the first straight line portions 11 and the second straight line portions 12, laser processing in which a laser beam is scanned is preferably used because fine grooves can be formed with high accuracy. In this embodiment, the opening induction band 6 is formed on the outer surface of one of the packaging materials 2. The opening induction band 6 may be formed on the inner surface of the packaging material 2, or may be formed on both packaging materials 2.

As shown in FIG. 2, the first straight portion 11 extends linearly in a direction inclined relative to the opening direction indicated by the arrow X. The second straight portion 12 extends linearly in a direction inclined in the opposite direction to the first straight portion 11 relative to the opening direction. The first straight portion 11 and the second straight portion 12 have approximately the same length. The lengths of the first straight portion 11 and the second straight portion 12 may be an appropriate length that makes it easy to tear the packaging material 2, and from the viewpoint that if the length is too long, the tearing guidance decreases, the length is, for example, about 0.5 mm to 20 mm, and more preferably 2 mm to 10 mm.

Each of the three rows of weakened line portions 10 is arranged in a zigzag pattern with first straight line portions 11 and second straight line portions 12 that are arranged along the opening direction without intersecting with each other and have mountain-shaped portions 13 and valley-shaped portions 14. Each weakened line portion 10 has a non-weakened line portion 15 between the first straight line portion 11 and second straight line portion 12 adjacent to each other in the opening direction, which is not half-cut and has the same thickness as the packaging material 2.

The three rows of weak line portions 10 are spaced equally apart in the vertical direction. The opening direction positions of the first straight line portions 11 and the opening direction positions of the second straight line portions 12 of each weak line portion 10 are aligned and overlap each other in the vertical direction. In each weak line portion 10, the first straight line portion 11 and the second straight line portion 12 adjacent to each other in the opening direction are slightly offset in the vertical direction. In addition, the opening direction positions of the ends of the first straight line portion 11 and the second straight line portion 12 adjacent to each other in the opening direction are aligned and overlap each other in the vertical direction. The width dimension and number of each of the mountain-shaped portions 13 and valley-shaped portions 14 are appropriately selected according to the width of the packaging bag 1.

As shown in FIG. 2, the inclination angle θ1 of the first straight portion 11 relative to the opening direction and the inclination angle θ2 of the second straight portion 12 relative to the opening direction are the same angle, for example, about 10° to 60°. Therefore, the mountain portion 13 and the valley portion 14 formed by the first straight portion 11 and the second straight portion 12 each form an isosceles triangle shape with a line along the opening direction as its base. At the same time, the angles of the corner 13a forming the apex of the mountain portion 13 and the corner 14a forming the bottom of the valley portion 14 are the same, 60° to 150°, and more preferably 90° to 120°.

In the packaging bag 1 of this embodiment, by tearing the packaging material 2 from one notch 8 toward the opening guidance band 6, the cuts caused by the tearing are transmitted in sequence to each straight line portion 11, 12 of the weakened line portion 10, and each straight line portion 11, 12 and the non-weakened line portion 15 between these straight line portions 11, 12 are inductively torn. The tearing causes the breakage of the packaging material 2 to progress in the opening direction, and the opening guidance band 6 is broken, and the packaging bag 1 is opened.

In FIG. 3, when a tearing force is applied in the direction of the arrow X1, the force tears the first straight line portion 11 (11a) of one of the weak line portions 10, and then the tearing force is directed in the direction of extension of the first straight line portion 11 (11a) (indicated by the arrow F1), tearing the non-weak line portion 15, the slit reaches the adjacent second straight line portion 12 (12a), and then this second straight line portion 12 (12a) is torn. When the second straight line portion 12 (12a) is further torn, the tearing force is directed in the direction of extension of the second straight line portion 12 (12a) (indicated by the arrow F2), tearing the next non-weak line portion 15, and the slit reaches the next first straight line portion 11 (11b).

In this way, as the non-weakened line portions 15 between the straight line portions 11, 12 are torn, the cuts are always passed on to the straight line portions 11, 12, and these straight line portions 11, 12 are torn alternately and one after the other, so that the tearing of the opening guide belt 6 progresses in a zigzag pattern and the packaging bag 1 is opened. As the cuts are formed in the order of the first straight line portion 11, the non-weakened line portions 15, and the second straight line portion 12, the sound of the tearing can be heard at a constant rhythm, and the intermittent resistance caused by the tearing is felt by the fingers, providing a pleasant sensation.

In the above-mentioned opening operation, if the tearing force is strong, a cut may extend from the non-weakened line portion 15, for example, across the second straight line portion 12 to the adjacent weak line portion 10. In that case, however, the second straight line portion 12 or the first straight line portion 11 of the adjacent weak line portion 10 is torn to form a cut. In other words, the broken weak line portion 10 moves to the adjacent weak line portion 10, and the break continues to progress along the opening direction in that weak line portion 10. Even if a strong tearing force is applied in a direction that intersects with the intended opening line 7 in this way, the tearing force is guided by the straight line portions 11, 12 to follow the intended opening line 7, and the break progresses.

The packaging bag 1 according to the present embodiment described above includes a plurality of sheet-like packaging materials 2 that are stacked on top of each other, a sealing section 4 where the peripheral portions 3 of the plurality of packaging materials 2 are bonded to each other, a storage section 5 that is formed between the plurality of packaging materials 2 and is sealed by being surrounded by the sealing section 4, and an opening guide band 6 that is provided on the packaging material 2 along an intended opening line 7 that is set between any two points of the sealing section 4 and extends in the opening direction. The opening guide band 6 extends over substantially the entire length of the intended opening line 7 and has multiple rows (three rows) of weakened line portions 10 formed by half-cut grooves that are formed by removing a part of the thickness direction of the packaging material 2 from the surface. The weakened line portions 10 include a plurality of first straight line portions 11 that are inclined with respect to the opening direction and a plurality of second straight line portions 12 that are inclined in the opposite direction to the first straight line portions 11 with respect to the opening direction. The first straight line portions 11 and the second straight line portions 12 are arranged along the opening direction, so that the zigzag pattern has mountain-shaped portions 13 and valley-shaped portions 14.

As a result, when opening the packaging material 2, the cut is reliably guided to the first straight portion 11 and the second straight portion 12 over the entire length of the intended opening line 7, allowing for smooth opening. In addition, the lines of weakness that guide the opening are the straight first straight portion 11 and the second straight portion 12, and since they are not curved, the lines of weakness can be easily formed by laser processing, etc.

In the packaging bag 1 according to this embodiment, the first straight line portion 11 and the second straight line portion 12 are approximately the same length and are arranged intermittently and alternately along the opening direction, and in the opening guidance band 6, the positions of the first straight line portion 11 and the second straight line portion 12 of adjacent weak line portions 10 are approximately the same in the opening direction.

As a result, the zigzag pattern of the opening guidance band 6 formed by the first straight portion 11 and the second straight portion 12 has a regular and simple shape, so that the opening guidance band 6 can be easily formed by laser processing or the like. In addition, since the positions of the first straight portion 11 and the second straight portion 12 of the weak line portion 10 are substantially the same and aligned in the opening direction, when the tearing force is strong, the cut is reliably guided to each straight portion 11, 12 of the adjacent weak line portion 10, and the opening operation can proceed smoothly along the intended opening line 7.

In the packaging bag 1 according to this embodiment, the mountain-shaped portion 13 and the valley-shaped portion 14 each form an isosceles triangle with a line along the opening direction as its base, and the angles of the corners forming the apex of the mountain-shaped portion 13 and the corners forming the apex of the valley-shaped portion 14 are the same and are between 60° and 150°.

As a result, the first straight portion 11 and the second straight portion 12 forming the mountain portion 13 and the valley portion 14 are gently inclined with respect to the opening direction, so that the tearing force is reliably transmitted along the first straight portion 11 and the second straight portion 12, and these straight portions 11, 12 can be reliably torn. In addition, because the zigzag pattern of the opening guidance band 6 is a regular and simple shape, the opening guidance band 6 can be easily formed by laser processing, etc.

In the packaging bag 1 according to this embodiment, the first straight line portion 11 and the second straight line portion 12 are arranged along the opening direction without intersecting with each other, so that no area is formed whose entire circumference is surrounded by the straight line portions 11, 12. For example, as shown in FIG. 4, when two zigzag weak lines 19 are formed by half-cutting with a phase shift in the opening direction, multiple diamond-shaped areas 19a are formed whose entire circumference is surrounded by the weak lines 19. In this case, for example, if the weak lines 19 surrounding the areas 19a are broken all around, the areas 19a may fall off and become mixed in with the contents as foreign matter. However, in this embodiment, the first straight line portion 11 and the second straight line portion 12 do not intersect with each other, so there is no risk of partial fragments being generated in the packaging material 2 and the fragments falling off.

In the packaging bag 1 according to this embodiment, the opening guide band 6 is formed on the outer surface of one of the two packaging materials 2. For this reason, as shown in FIG. 3, in the packaging material 2B on the side on which the opening guide band 6 is not formed, there is a portion where the cut edge 2b does not align with the cut edge 2a of the packaging material 2A on the side on which the opening guide band 6 is formed, as shown in FIG. 3. This makes it easier to separate the cut edges 2a, 2b and open the opening.

Next, second to fourth embodiments of the present invention will be described below. Note that in these embodiments, the same components as in the first embodiment are given the same reference numerals, and their explanation will be omitted, with the main focus being on the differences from the first embodiment.

Second Embodiment
5 shows a packaging bag 1 according to a second embodiment. The packaging bag 1 according to the second embodiment includes an opening guide strip 20 instead of the opening guide strip 6 of the first embodiment. The opening guide strip 20 has three rows of weak line portions 10, similar to the first embodiment. Each of the weak line portions 10 has a plurality of first weak line patterns 21 along the opening direction.

As shown in FIG. 6, the first weak line pattern 21 includes a first straight line portion 11 that is inclined with respect to the opening direction, and a second straight line portion 12 that is inclined in the opposite direction to the first straight line portion 11 with respect to the opening direction. The length of the first straight line portion 11 is shorter than the length of the second straight line portion 12. The first weak line pattern 21 has a substantially Z-shaped pattern in which one second straight line portion 12 is arranged between two first straight line portions 11 along the opening direction. The length of the first straight line portion 11 is, for example, about 0.5 mm to 10 mm, and the length of the second straight line portion 12 is, for example, about 1 mm to 30 mm. In this range, the length of the first straight line portion 11 is more preferably 1 mm to 5 mm, and the length of the second straight line portion 12 is more preferably 2 mm to 10 mm.

In the first weak line pattern 21, the first straight line portion 11 is continuous with the second straight line portion 12 on both the left and right sides, and in FIG. 6, a mountain-shaped portion 13 is formed at the left end and a valley-shaped portion 14 is formed at the right end. In each of the three rows of weak line portions 10, the multiple first weak line patterns 21 are arranged alternately with a phase shift in the opening direction, so that the mountain-shaped portions 13 and valley-shaped portions 14 overlap in a diamond shape in the up-down direction approximately perpendicular to the opening direction and are spaced apart from each other. As the first weak line patterns 21 are spaced apart in the up-down direction, the weak line portion 10 has a non-weak line portion 15 between the end of the first straight line portion 11 and the middle portion of the second straight line portion 12, which remains the same thickness as the packaging material 2 that is not half-cut.

The inclination angle of each straight portion 11, 12 with respect to the opening direction is the same, and each mountain portion 13 and valley portion 14 form an isosceles triangle with a line along the opening direction as its base. The angles of corner 13a forming the apex of mountain portion 13 and corner 14a forming the bottom of valley portion 14 are the same, and are between 60° and 150°, as in the first embodiment.

According to the second embodiment of the opening guidance band 20, for example, when the opening guidance band 20 is torn from the left side in Figs. 5 and 6, the opening guidance band 20 is torn as follows. In one weak line portion 10, the first straight line portion 11 of the first first weak line pattern 21 is torn, then the second straight line portion 12 connected to the first straight line portion 11 is torn to tear the mountain-shaped portion 13, and then the first straight line portion 11 connected to the second straight line portion 12 is torn to tear the valley-shaped portion 14. That is, first, one first weak line pattern 21 is torn. Next, the force that tore the first straight line portion 11 is guided to the first straight line portion 11 and tears the non-weak line portion 15, and the cut moves to the second straight line portion 12 of the upper first weak line pattern 21. The second straight line portion 12 is then torn from approximately the center to the right, tearing the valley portion 14, and then guided by the first straight line portion 11, the next non-weakened line portion 15 is torn, and the break moves to near the center of the second straight line portion 12 of the next upper first weak line pattern 21. Note that this pattern of break transition is one example and is not limited to this.

In this way, the cuts move from the lower portion of the first weak line pattern 21 to the upper first weak line pattern 21, and while the non-weak line portion 15 between each straight line portion 11, 12 is broken, the cuts are always passed on to each straight line portion 11, 12, and these straight line portions 11, 12 are alternately and one after another torn, so that the tearing of the opening guidance strip 20 progresses in a zigzag manner and the packaging bag 1 is opened. Note that, when the opening guidance strip 20 is torn from the right side in Figures 5 and 6, the straight line portions 11, 12 are torn in the reverse order to the above, and in that case, the cuts move from the upper portion of the first weak line pattern 21 to the lower first weak line pattern 21, and the tearing progresses from the right side to the left side. The opening direction is selected by the user, for example, according to their dominant hand.

According to the second embodiment, when opening the packaging material 2, the cut is reliably guided to the first straight portion 11 and the second straight portion 12 over the entire length of the intended opening line 7, allowing smooth opening. In addition, the weak lines that guide the opening are the straight first straight portion 11 and the second straight portion 12, and do not have curves, so that the weak lines can be easily formed by laser processing, etc.

In addition, according to the second embodiment, in the weak line portion 10, the peak portions 13 and valley portions 14 of the first weak line pattern 21 overlap in a diamond shape in the vertical direction and are spaced apart from each other, forming a non-weak line portion 15. As a result, no area is formed in the packaging material 2 that is entirely surrounded by the first straight portion 11 and the second straight portion 12. Therefore, no fragments are generated as shown in FIG. 4 when the package is opened, and the fragments do not fall off and become mixed in with the contents.

Third Embodiment
Fig. 7 shows a packaging bag 1 according to a third embodiment. As shown in Fig. 8, the packaging bag 1 according to the third embodiment differs from the second embodiment only in that in the opening guidance strip 20 of the second embodiment, the first straight line portion 11 and the second straight line portion 12 of the first weak line pattern 21 are separated from each other, and a non-weak line portion 16 is provided in the separated portion.

According to the third embodiment, as in the second embodiment, the opening guidance band 20 allows smooth opening and the opening guidance band 20 can be easily formed. In addition, since the non-weakened line portion 16 is added to the second embodiment, the strength of the opening guidance band 20 is slightly stronger than that of the second embodiment, and therefore, when applied to a case where the thickness of the packaging material 2 is relatively thin, the opening guidance band 20 is less likely to become excessively weak.

Fourth Embodiment
9 shows a packaging bag 1 according to a fourth embodiment. The packaging bag 1 according to the fourth embodiment has an opening guidance strip 30 instead of the opening guidance strip 6 of the first embodiment. The opening guidance strip 30 has three rows of weak line portions 10, similar to the first embodiment. Each of the weak line portions 10 has a plurality of second weak line patterns 31 arranged intermittently along the opening direction.

The second weak line pattern 31 is a pattern in which the mountain-shaped portions 13 and the valley-shaped portions 14 are overlapped in a diamond shape while being spaced apart in the up-down direction substantially perpendicular to the opening direction. Each of the mountain-shaped portions 13 and the valley-shaped portions 14 has a first straight portion 11 and a second straight portion 12 that are the same length and are continuous with each other. The first straight portion 11 and the second straight portion 12 are inclined in opposite directions to each other with respect to the opening direction, and the inclination angles are the same, and each of the mountain-shaped portions 13 and the valley-shaped portions 14 forms an isosceles triangle shape with a line along the opening direction as its base. The angles of the corners 13a that form the apex of the mountain-shaped portions 13 and the corners 14a that form the bottom of the valley-shaped portions 14 are the same and are 60° to 150° as in the first embodiment.

The mountain-shaped portion 13 and the valley-shaped portion 14 of the second weak line pattern 31, which are spaced apart in the vertical direction, are spaced apart at both left and right ends of the first straight portion 11 and the second straight portion 12, close to each other. The second weak line pattern 31 has a non-weak line portion 17 in the spaced portion, which has the same thickness as the packaging material 2 that is not half-cut. Furthermore, the weak line portion 10 has a non-weak line portion 18 between adjacent second weak line patterns 31 in the opening direction, which has the same thickness as the packaging material 2 that is not half-cut. In the opening guidance strip 30 according to the fourth embodiment, the positions of the second weak line patterns 31 of adjacent weak line portions 10 in the vertical direction are approximately the same and aligned in the opening direction.

According to the opening induction strip 30 of the fourth embodiment, when a tearing force is applied to the opening induction strip 30 along the opening direction, in one of the weak line portions 10, either the mountain-shaped portion 13 or the valley-shaped portion 14 of the first second weak line pattern 31 is torn. For example, when the mountain-shaped portion 13 is torn first, the first straight portion 11 and the second straight portion 12 of the mountain-shaped portion 13 are cut in that order, then the non-weak line portion 17 is torn and moves to the adjacent mountain-shaped portion 13, the first straight portion 11 and the second straight portion 12 are cut in order, and then the non-weak line portion 17 is torn and moves to the adjacent mountain-shaped portion 13. In this way, the mountain-shaped portions 13 are torn in sequence while the non-weak line portion 17 is torn, and the opening induction strip 30 is broken in a zigzag shape and opened. Also, if the valley portion 14 is torn first, the valley portions 14 are torn in sequence, and the opening induction band 30 is torn in a zigzag pattern and opened. Note that it is not always the case that only the peak portion 13 or only the valley portion 14 is torn; the cut may be transmitted alternately to the peak portion 13 and the valley portion 14, or they may be torn in random order.

According to the fourth embodiment, when the packaging material 2 is cut and opened, the cut is reliably guided to the second weak line pattern 31 over the entire length of the intended opening line 7, allowing smooth opening. In addition, the weak lines that guide the opening are the first straight line portion 11 and the second straight line portion 12, which are linear, and do not have curves, so that the weak lines can be easily formed by laser processing, etc.

Furthermore, according to the fourth embodiment, in the weak line portion 10, the peaks 13 and valleys 14 of the second weak line pattern 31 overlap in a diamond shape in the vertical direction and are spaced apart from each other, forming a non-weak line portion 17. As a result, no area is formed in the packaging material 2 that is entirely surrounded by the peaks 13 and valleys 14. Therefore, no fragments are generated when the package is opened, and the fragments do not fall off and get mixed into the contents.

The present invention is not limited to the aspects of each of the above-mentioned embodiments, and can be modified as appropriate. For example, the packaging material 2 may be a sheet-like material other than resin, and may be composed of, for example, a sheet-like paper of an appropriate thickness. In addition, the inclination angles of the first straight line portion 11 and the second straight line portion 12 with respect to the opening direction are the same in each of the above-mentioned embodiments, but may be different. In addition, for example, the multiple first straight line portions 11 may have two different inclination angles, and be arranged so that they are alternately different in the opening direction.

In each of the above embodiments, there are three rows of weakened lines 10 extending in the opening direction, but in the present invention, there is no limit to the number of rows as long as there are two or more rows, and the number of rows is selected, for example, depending on the width (vertical length dimension) of the weakened lines 10. The number of arrangements of the peaks 13 and valleys 14 in the opening direction and their spacing (pitch) are arbitrary and are determined appropriately depending, for example, on the ease of tearing depending on the material of the packaging material 2.

REFERENCE SIGNS LIST 1 Packaging bag 2 Packaging material 3 Periphery 4 Sealed portion 5 Storage portion 6, 20, 30 Opening guidance strip 7 Opening line 10 Weak line 11 First straight portion 12 Second straight portion 13 Mountain-shaped portion 13a Corner portion forming the apex of the mountain-shaped portion 14 Valley-shaped portion 14a Corner portion forming the apex of the valley-shaped portion 21 First weak line pattern 31 Second weak line pattern

Claims (4)

A plurality of sheet-like packaging materials that can be stacked on top of each other;
a sealing portion where peripheral portions of the plurality of packaging materials are bonded to each other;
a storage section formed between the plurality of packaging materials and surrounded and sealed by the sealing section;
An opening guide band is provided on the packaging material along an opening line extending in an opening direction set between any two points of the sealing portion,
The opening guide band extends over substantially the entire length of the opening line and has a plurality of rows of weakened lines formed by half-cut grooves formed by removing a portion of the packaging material from the surface in the thickness direction,
the line of weakness includes a plurality of first straight line portions inclined with respect to the opening direction and a plurality of second straight line portions inclined in a direction opposite to the first straight line portions with respect to the opening direction, and the first straight line portions and the second straight line portions are arranged along the opening direction to form a zigzag pattern having mountain-shaped portions and valley-shaped portions ;
the weak line portion has a first weak line pattern having a generally Z-shape in which the length of the first straight portion is shorter than the length of the second straight portion and one of the second straight portions is disposed between two of the first straight portions along the opening direction, and a plurality of the first weak line patterns are alternately arranged with a phase shift in the opening direction such that the peak-shaped portions and the valley-shaped portions overlap in a diamond shape in a direction generally perpendicular to the opening direction, and the plurality of first weak line patterns are spaced apart. The packaging bag according to claim 1 , wherein the first line of weakness pattern is continuous with the first straight line portion and the second straight line portion. The packaging bag according to claim 1 , wherein the first line of weakness pattern is such that the first straight line portion and the second straight line portion are spaced apart from each other. Each of the mountain-shaped portion and the valley-shaped portion forms an isosceles triangle shape with a line along the opening direction as a base,
The packaging bag according to any one of claims 1 to 3 , wherein the angles of the corners forming the apexes of the mountain-shaped portions and the corners forming the bottoms of the valley-shaped portions are the same and range from 60° to 150°.

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