JP7471502B2 - Food packaging bags - Google Patents

Description

The present invention relates to a food packaging bag.

There are foods such as sandwiches that have a triangular (usually right-angled) side shape or a similar shape and are finished into a three-dimensional shape with a specified thickness or width. A typical food packaging bag for packaging this food is shown in Figure 23.

The food packaging bag 1' comprises a bag body 10' and a header portion 15'. The bag body 10' is made by overlapping a pair of sheets 2', 3' each having a shape in which the other end is wider than the other end, and is sealed on three sides by a top joint 11' at one end and side joints 12', 12' at both side edges, with the other end forming an opening 13'. The header portion 15' is made by joining the protruding pieces of the sheets 2', 3' protruding from the top joint 11' at appropriate points to each other and integrating them.

The food packaging bag 1' described in Patent Document 1 has an X-shaped cut line 32' formed in the second sheet 3' at a location of the bag body 10' close to the top joint 11', and an opening strip 5' such as a cutting tape is joined to the inner surface of the second sheet 3' from a free piece formed by the inverted V-shaped part below the cut line 32' to the other end side of the second sheet 3', and an opening means is provided in which a covering piece 6' is joined to the outer surface of the second sheet 3' so as to cover the cut line 32'.

When eating food packaged in the food packaging bag 1', the covering piece 6' is pinched and pulled down as shown in FIG. 24(a). This pulls the opening strip 5', forming a vertical tear-open section in the second sheet 3', through which the food can be exposed. If it is desired to open the food package further, the second stage of opening is to open the torn second sheet 3' to the left and right from the torn end 38' as shown in FIG. 24(b). This causes the second sheet 3' to tear in the left and right direction, starting from the end point of the V-shaped portion above the cut line 32'. This allows the tear-open section to be opened wide, exposing the food.

JP 2004-142764 A

However, the V-shaped portion above the cut line 32' is composed of a diagonal line, and therefore has a component that crosses diagonally in the left-right direction at the end point. For this reason, the tearing of the second sheet 3' may be induced toward the top joint 11 by the left-right opening operation. In this case, the tearing of the second sheet 3' may be stopped by the resistance at the top joint 11, and it may not be possible to open it any further.

Therefore, the present invention was made in consideration of these circumstances, and aims to provide a food packaging bag that can be opened appropriately and reliably in a wide width from left to right.

The food packaging bag according to the present invention is
a bag body including a pair of overlapping sheets each having a shape in which one end side is wider than one end side in a first direction, the bag body being sealed on three sides by a top joint part at one end side and side joint parts at both side edges, and the other end side being an opening,
One sheet is
At least, the film has a tear directionality in a first direction or a second direction perpendicular to the first direction;
a first cut line having both ends directed toward the other end of the sheet and forming a free piece that is convex toward one end of the sheet on the inside;
a second cut line extending from both side edges (excluding both end points of the first cut line) of the free piece to the outside of the free piece in a second direction and not having a component in a direction obliquely intersecting the second direction at the end points;
The food packaging bag is provided with an opening strip disposed on the inner surface of the sheet and extending from the free piece to the other end side of the sheet.

In addition, the food packaging bag according to the present invention is
a bag body including a pair of overlapping sheets each having a shape in which one end side is wider than one end side in a first direction, the bag body being sealed on three sides by a top joint part at one end side and side joint parts at both side edges, and the other end side being an opening,
One sheet is
At least, the film has a tear directionality in a first direction or a second direction perpendicular to the first direction;
a first cut line having both ends directed toward the other end of the sheet and forming a free piece that is convex toward one end of the sheet on the inside;
a second cut line extending from a tip edge of the free piece to an outside of the free piece in a first direction and not having a component in a direction obliquely intersecting with the second direction at an end point of the first cut line;
The food packaging bag is provided with an opening strip disposed on the inner surface of the sheet and extending from the free piece to the other end side of the sheet.

As described above, according to the food packaging bag of the present invention, the second cut line involved in opening the bag from the left and right is a cut line that does not have a component that intersects obliquely with the second direction at its end point, so the tearing of the sheet does not stop midway, and the bag can be opened appropriately and reliably in a wide left and right direction.

FIG. 1 is an exploded perspective view of a food packaging bag according to one embodiment of the present invention. FIG. 2 is a front view of the food packaging bag. FIG. 3 is a rear view of the food packaging bag. Fig. 4(a) is a front view of a second sheet constituting the food packaging bag, and Fig. 4(b) is an enlarged view of the opening starting point of Fig. 4(a). Fig. 5(a) is an enlarged view of the opening starting point in a state where the covering piece is joined, and Fig. 5(b) is a cross-sectional view taken along line AA in Fig. 5(a). Fig. 6(a) is a perspective view of a food package packaged in the food packaging bag as viewed from the back side, and Fig. 6(b) is a perspective view of the food package being opened. 7(a) and (b) are perspective views showing how the food package is further opened. FIG. 8 is an explanatory diagram of the manufacturing process of the food packaging bag, specifically, an explanatory diagram of a step of forming score lines in the second raw sheet. FIG. 9 is an explanatory diagram of the manufacturing process of the food packaging bag, specifically, an explanatory diagram of the process of arranging and joining the opening strip to the second raw sheet. 10(a) and (b) are explanatory diagrams of the configuration of an apparatus for carrying out the steps of FIG. FIG. 11 is an explanatory diagram of the manufacturing process of the food packaging bag, illustrating the step of protruding one end of the opening strip from the cut line to the opposite surface side of the second raw sheet. FIG. 12 is an explanatory diagram seen from the opposite side to FIG. 13(a) to (c) are explanatory diagrams of the configuration of an apparatus for carrying out the process of FIG. 14(a) to (c) are explanatory diagrams of another apparatus configuration for carrying out the process of FIG. FIG. 15 is an explanatory diagram of the manufacturing process of the food packaging bag, specifically, an explanatory diagram of the step of overlapping and joining the first and second raw sheet rolls. FIG. 16 is an explanatory diagram of the manufacturing process of the food packaging bag, illustrating each step up to the final completion of the food packaging bag. FIG. 17 is an exploded perspective view of a food packaging bag according to another embodiment. FIG. 18 is a front view of the food packaging bag. FIG. 19 is a rear view of the food packaging bag. Fig. 20(a) is an enlarged view of the opening starting point in a state where the covering piece is joined, and Fig. 20(b) is a cross-sectional view taken along line AA in Fig. 20(a). 21(a) to (f) are enlarged views of the opening starting point of a food packaging bag according to another embodiment. 22(a) to (e) are enlarged views of an opening starting point of a food packaging bag according to still another embodiment. FIG. 23 is a rear view of a conventional food packaging bag. Fig. 24(a) is a perspective view of a food package packaged in the food packaging bag from the back side, showing how the food package is opened, and Fig. 24(b) is a perspective view of how the food package is further opened.

Below, a food packaging bag used for packaging sandwiches will be described as one embodiment of the food packaging bag according to the present invention with reference to Figures 1 to 16.

As shown in Figures 1 to 3, the food packaging bag 1 according to this embodiment comprises a bag body 10 and a header portion 15. The bag body 10 is made by overlapping a pair of sheets (a first sheet 2, a second sheet 3) each having a shape in which one end is wider than the other end, and is sealed on three sides by a top joint 11 at one end and side joints 12, 12 at both side edges, with the other end forming an opening 13. The header portion 15 is formed by joining the protruding pieces of the sheets 2, 3 protruding from the top joint 11 to each other at appropriate points and integrating them. The first sheet is also called the front sheet, and the second sheet is also called the back sheet.

The first sheet 2 is made of a plastic sheet having heat sealability, such as polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET). In this embodiment, the first sheet 2 is a sheet of biaxially oriented polypropylene (OPP). As a result, the first sheet 2 has tear directionality (straight-line cutability) in a first direction (longitudinal direction, vertical direction in Figs. 1 and 2) and a second direction (width direction, horizontal direction in Figs. 1 and 2) perpendicular to the first direction. The first sheet 2 is composed of a body 20 and a tip 21 (the above-mentioned protruding piece). The body 20 has a shape that gradually becomes wider from one end side to the other end side. The tip 21 has a narrow shape that extends from one end of the body 20.

The second sheet 3 is also made of a plastic sheet having heat sealability, such as polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET). In this embodiment, the second sheet 3 is also a sheet of biaxially oriented polypropylene (OPP). As a result, the second sheet 3 also has tear directionality (straight-line cutability) in the first and second directions. The second sheet 3 is configured with a body 30 and a tip 31 (the above-mentioned protruding piece). The body 30 has a shape that gradually becomes wider from one end side to the other end side. The tip 31 has a narrow shape that extends from one end of the body 30.

In this embodiment, the body portions 20, 30 are trapezoidal, and the tip portions 21, 31 are rectangular. Therefore, one end of the body portions 20, 30 (and the other end of the tip portions 21, 31 that coincides with it) is linear and perpendicular to the first direction. In other words, one end of the body portions 20, 30 is linear and parallel to the second direction. Both side edges of the body portions 20, 30 are linear and inclined with respect to the first direction. Both side edges of the tip portions 21, 31 are linear and parallel to the first direction. However, the other end side of both side edges of the body portions 20, 30 is missing due to the notch portions 14. As a result, the other end side of the body portions 20, 30 is narrowed by the amount of the notch portions 14.

The top joint 11 is formed by heat sealing the first and second sheets 2, 3 along one end of the body 20, 30. The side joint 12 is formed by heat sealing the side edges (oblique sides) of the body 20, 30 and the side edges (vertical sides) of the tip portions 21, 31. In this embodiment, the top joint 11 is a strip seal formed by welding using a heat seal bar and has a predetermined width in the first direction. The side joint 12 is a line seal formed by melt cutting. Specifically, the top joint 11 has a width of several millimeters or more. The width of the side joint 12 is 1 mm or less.

The interior of the bag body 10 constructed in this manner serves as the food storage section. An inner sheet 4 is attached to the inner surface of the first sheet 2 in the bag body 10. The other end of the inner sheet 4 is joined at two points, for example, by point sealing or the like (joints 40), and one end is a free end. As a result, even if the food moves within the storage section, the inner sheet 4 adheres closely to the surface of the food and follows its movement. Therefore, the first sheet 2 does not get dirty, and its appearance is not impaired.

As shown in FIG. 4, a first cut line 32 and a second cut line 34 are formed in the second sheet 3. The first cut line 32 forms a first free piece 33 in the second sheet 3, and the second cut line 34 forms a second free piece 35 in the second sheet 3. The first cut line 32 and the second cut line 34 are formed in the second sheet 3 in the bag body 10, in a location close to the top joint 11.

The first cut line 32 has a shape in which both end points 32a, 32a are spaced apart from the top joint 11. That is, the first cut line 32 is shaped toward the other end of the second sheet 3. The first free piece 33 has the first cut line 32 as an outline, the area between both end points 32a, 32a as a fixed end, and one end side of the second sheet 3 as a free end, and when bent at the fixed end side, opens to form an opening. In this embodiment, the first cut line 32 is formed in an arc shape with an angle of 180°. As a result, the first free piece 33 has a tip edge 33a along the second direction and a pair of left and right side edges 33b, 33b along the first direction, and is a circular arc piece that is convex toward one end side of the second sheet 3 and has directionality toward the other end of the second sheet 3.

The second cut line 34 is formed between the first cut line 32 and the top joint 11. The second cut line 34 has a shape in which both end points 34a, 34a approach the top joint 11. That is, the second cut line 34 is shaped toward one end of the second sheet 3. The second free piece 35 has the second cut line 34 as its outline, the area between both end points 34a, 34a as its fixed end, and the other end side of the second sheet 3 as its free end, and when bent at the fixed end side, it opens to form an opening. In this embodiment, the second cut line 34 is formed in an arc shape with an angle of 180°. As a result, the second free piece 35 has a tip edge along the second direction and a pair of left and right side edges along the first direction, is convex toward the other end side of the second sheet 3, and is an arc piece with directionality toward one end of the second sheet 3.

The first cut line 32 and the second cut line 34 are formed so that their leading edges are in contact with each other. Then, in the second sheet 3, a third free piece 36 is formed by forming the left part of the first cut line 32 and the second cut line 34, and a fourth free piece 37 is formed by forming the right part of the first cut line 32 and the second cut line 34. As a result, the first free piece 33 and the second free piece 35 are formed to face each other in the first direction, and the third free piece 36 and the fourth free piece 37 are formed to face each other in the second direction, centered on the leading edges of the first cut line 32 and the second cut line 34.

On the inner surface of the second sheet 3, an opening strip 5 is provided from the first free piece 33 to the other end of the second sheet 3. The opening strip 5 is provided, for example, along the first direction at the center of the second sheet 3 in the second direction. The opening strip 5 is joined to the inner surface of the second sheet 3 by heat sealing, adhesion, or the like (joint 50). As an example, the opening strip 5 is joined to the inner surface of the second sheet 3 by heat adhesion or self-adhesion after a coating agent is applied to this inner surface (the surface facing the second sheet 3). The opening strip 5 is, for example, a cut tape or thread. In this embodiment, the opening strip 5 is a strip-shaped cut tape having a width of 5 mm or more or 10 mm or more. The cut tape is a thin cut from a plastic sheet having heat sealability, such as biaxially oriented polyester, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), or biaxially oriented polypropylene (OPP).

One end 5a of the opening strip 5 is not joined to the second sheet 3. One end 5a of the opening strip 5 protrudes from the first cut line 32 toward the outer surface side of the second sheet 3, and serves as a picking piece for opening. As a result, when one end 5a of the opening strip 5 is picked up and pulled down, the opening strip 5 is pulled, and the second sheet 3 is cut at a predetermined width with the first free piece 33 as the opening starting point, and a divided opening portion is formed in the second sheet 3. If the protruding amount of the one end 5a of the opening strip 5 is short, it is difficult to pick up. On the other hand, if it is long, it is easy to break, and there is a concern that it may interfere with the transportability of the manufacturing device. For this reason, the protruding amount of the one end 5a of the opening strip 5 is set to be in the range of 5 mm or more, 10 mm or more, or 15 mm or more, and 25 mm or less, or 20 mm or less. In this embodiment, the amount of protrusion of one end 5a of the opening strip 5 is set so that the one end 5a fits within the area of the second free piece 35 and does not protrude beyond the second free piece 35.

As shown in FIG. 4(b), the opening strip 5 is also joined to the first free piece 33 and is integrated with the first free piece 33. However, the opening strip 5 is not joined to the leading edge 33a of the first free piece 33. Therefore, a non-jointed portion of width G1 is interposed between the leading edge 50a of the joint 50 and the leading edge 33a of the first free piece 33. If the non-jointed portion is not provided or the width G1 is small, there is a concern that the joining will go beyond the first cut line 32 due to the influence of the precision of the manufacturing device for the food packaging bag 1 (such as the meandering of the sheet raw material). In this case, one end 5a of the opening strip 5 will be locked, and the one end 5a will not be able to protrude from the first cut line 32 to the outer surface side of the second sheet 3. On the other hand, if the width G1 is large, the first free piece 33 can be picked up, and there is a concern that an erroneous opening operation will be performed by picking up this part to open the bag. In this case, the opening strip 5 is not used, and only the second sheet 3 is pulled, making it impossible to open properly. For this reason, the width G1 of the non-jointed portion is set to a range of 1 mm or more, or 1.5 mm or more, and 5 mm or less, or 3 mm or less, or 2 mm or less, as a margin of variation for manufacturing errors.

The width of the opening strip 5 is smaller than the width of the fixed end of the first free piece 33 (i.e., the distance between both ends 32a, 32a of the first cut line 32). Therefore, a gap of width G2 is interposed between each side edge 5b of the opening strip 5 and each side edge 33b of the first free piece 33 or each end point 32a of the first cut line 32. If no gap is provided or the width G2 is small, there is a concern that one end 5a of the opening strip 5 will get caught on the first cut line 32 and the one end 5a will not be able to protrude from the first cut line 32 to the outer surface side of the second sheet 3. In addition, there is a concern that the opening strip 5 will get caught on the first cut line 32 due to the influence of the precision of the manufacturing device for the food packaging bag 1 (such as misalignment of the pasting position), causing wrinkles and resulting in a defective product. For this reason, the width G2 of the gap is set to be 1 mm or more, or 1.5 mm or more, to allow for a margin of error in manufacturing.

As shown in FIG. 5, a covering piece 6 is provided on the outer surface of the second sheet 3 as a sealant for covering and sealing the first cut line 32 and the first free piece 33, and the second cut line 34 and the second free piece 35 from the outer surface side of the second sheet 3, thereby preventing foreign matter from entering the interior through the cut lines 32, 34 and the free pieces 33, 35.

The covering piece 6 includes a main body 60 having a shape large enough to contain the cut lines 32, 34 and the free pieces 33, 35, and a gripping portion 61 protruding from the main body 60 toward one end of the second sheet 3. In this embodiment, the covering piece 6, the main body 60, and the gripping portion 61 are each rectangular.

The covering piece 6 is a plastic sheet having heat sealability, such as biaxially oriented polyester, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), or biaxially oriented polypropylene (OPP), cut into a predetermined shape. The main body 60 is joined to the outer surface of the second sheet 3 by heat sealing so as to cover the cut lines 32, 34 and the free pieces 33, 35 (joint 62). In this embodiment, the covering piece 6 is a sheet of polyethylene terephthalate (PET). As an example, the covering piece 6 is joined to the outer surface of the second sheet 3 by thermal adhesion or self-adhesive after a coating agent is applied to its inner surface (the surface facing the second sheet 3).

The joint 62 is a surface seal (solid seal). In this embodiment, the joint 62 is rectangular in shape to match the shape of the covering piece 6. However, from the perspective of improving the ease of peeling when the covering piece 6 is peeled off from the second sheet 3 by pinching the gripping portion 61, the edge 62a of the joint 62 on the gripping portion 61 side has an uneven shape. In this embodiment, the edge 62a of the joint 62 is a wavy shape with successive semicircular arcs.

The covering piece 6 is provided at the opening starting point, and by joining one end 5a of the opening strip 5, it also functions as an opening operation piece. For this reason, the covering piece 6 is joined to the second sheet 3 with an appropriate seal strength such that the main body 60 can be peeled off from the second sheet 3, but the main body 60 is difficult to peel off from the first free piece 33 and the one end 5a of the opening strip 5.

Since the first cut line 32 and the second cut line 34 are formed in a portion of the bag body 10 close to the top joint 11, the main body portion 60 of the covering piece 6 is joined to a portion of the bag body 10 close to the top joint 11. Therefore, the tab portion 61 of the covering piece 6 overlaps with the top joint 11 and advances into the header portion 15.

When packaging food, the opening 13 is opened, the food is inserted into the bag body 10, the excess sheet piece at the opening 13 (the piece of sheet sticking out from the bottom surface of the food) is folded appropriately, the opening 13 is closed, and a label or tape is attached to seal the opening 13. This completes the food package shown in Figure 6(a). In this food package, the tab 61 of the covering piece 6 is a free end that protrudes upward from the rear surface of the food package near the top joint 11.

When eating food, as shown in FIG. 6(b), the gripping portion 61 of the covering piece 6 is pinched and pulled as the first stage of the opening operation. The body portion 60 of the covering piece 6 is joined to the first free piece 33 and one end portion 5a of the opening strip 5. Therefore, when the gripping portion 61 of the covering piece 6 is pinched and pulled, the opening strip 5 is pulled and a severable opening portion is formed in the second sheet 3, and the food can be exposed from this severable opening portion. At this time, the gripping portion 61 of the covering piece 6 is slightly lifted and separated from the outer surface of the header portion 15, making it easier to grip. Alternatively, by warping the header portion 15, the gripping portion 61 of the covering piece 6 is sufficiently separated from the header portion 15, making it even easier to grip. This allows for a smooth opening operation.

If it is desired to open the food package further, the second stage of opening is to open the divided second sheet 3 from the divided end 38 to the left and right as shown in FIG. 7. If the divided end 38 of the divided second sheet 3 is pinched and pulled in the second direction, the second sheet 3 is torn in the second direction parallel to the top joint 11, starting from the end point 34a of the second cut line 34, since the second sheet 3 has a tearing directionality in the second direction. This allows the divided open portion to be opened widely, exposing a large amount of food. Note that the opening may be done by opening only one side as shown in FIG. 7(a), or the other side as shown in FIG. 7(b). Of course, both sides may be opened like a double door.

The food packaging bag according to this embodiment has the above configuration. Next, we will explain the manufacturing method of the food packaging bag according to this embodiment.

The manufacturing process can be broadly divided into a process of manufacturing a second sheet roll 3X having an opening means in which one end 5a of the opening strip 5 protrudes toward the outer surface of the second sheet 3 and serves as a tab for opening, as shown in Figs. 8 to 14, and a process of manufacturing a food packaging bag 1 from the first sheet roll 2X and the second sheet roll 3X, as shown in Figs. 15 and 16.

In addition, because of its shape, this type of trapezoidal food packaging bag 1 is manufactured so that it is oriented horizontally and alternately in the opposite directions with respect to the conveying direction of the sheet raw material 2X, 3X. That is, food packaging bags 1 with an opening 13 formed on one side of the width direction (TD) perpendicular to the conveying direction (MD) of the sheet raw material 2X, 3X and a header portion 15 formed on the other side of the width direction, and food packaging bags 1 with an opening 13 formed on the other side of the width direction and a header portion 15 formed on one side of the width direction are manufactured alternately. Therefore, in the following explanation and drawings, for convenience, the configuration related to the former food packaging bag 1 is labeled "one" and has "A" added after the reference number, and the configuration related to the latter food packaging bag 1 is labeled "the other" and has "B" added after the reference number. In this embodiment, the width direction of the sheet material 2X, 3X coincides with the first direction of the food packaging bag 1 (sheets 2, 3), and the conveying direction of the sheet material 2X, 3X coincides with the second direction of the food packaging bag 1 (sheets 2, 3).

The process for manufacturing the second sheet original 3X is one embodiment of a method for manufacturing a packaging sheet or a raw material for packaging sheet. The process includes the steps of: i) forming a first cut line 32 and a second cut line 34 in the second sheet original 3X as shown in FIG. 8; more specifically, forming the first cut line 32 and the second cut line 34 in the second sheet original 3X, forming the first cut line 32 to form a first free piece 33, and forming the second cut line 34 to form a second free piece 35 (first process); ii) arranging the opening strip 5 on the inner surface of the second sheet original 3X such that the part inside one end 5a of the opening strip 5 overlaps the first free piece 33, as shown in FIG. 9 and FIG. 10; iii) as shown in Figures 11 to 14, by applying an external force toward the first free piece 33, more specifically, toward the portion of the opening strip 5 in the first free piece 33, one end 5a of the opening strip 5 is moved to the opposite (outer) surface of the second sheet original 3X through the opening formed by the first free piece 33, and protrudes from the first cut line 32 to the opposite surface of the second sheet original 3X (third process).

In the first step, the second sheet roll 3X is transported intermittently. Then, a cutting mechanism (not shown) for one of the cut lines 32A, 34A and a cutting mechanism (not shown) for the other of the cut lines 32B, 34B, which are arranged on the transport path, operate in synchronization with the intermittent transport of the second sheet roll 3X, thereby forming the one of the cut lines 32A, 34B and the other of the cut lines 32B, 34B, respectively, as shown in FIG. 8.

As an example, the cutting mechanism includes a receiving roller and a tool. This cutting mechanism forms the cut lines 32, 34 in the second sheet raw roll 3X by reciprocating the tool on the receiving roller and abutting a notch blade provided on the surface of the tool against the receiving roller. However, the cutting mechanism is not limited to this configuration. The cutting mechanism may be a mechanism having a different configuration as long as it can form the cut lines 32, 34 in the second sheet raw roll 3X. In addition, the cutting mechanism may form the first cut line 32 and the second cut line 34 separately rather than simultaneously.

In the second step, the second sheet original 3X is intermittently transported. Then, as shown in FIG. 9 and FIG. 10, the cutting/conveying/joining mechanisms 100, 101 for the opening strip 5A and the cutting/conveying/joining mechanisms 100, 101 for the opening strip 5B, which are arranged on the transport path, operate in synchronization with the intermittent transport of the second sheet original 3X, so that the opening strip 5A and the opening strip 5B are each separated from the opening strip sheet original 5X, transported, and placed on the inner surface of the second sheet original 3X and joined (joints 50A and 50B).

As an example, the cutting mechanism 100 includes a pair of cutting blades. This cutting mechanism 100 cuts the sheet raw material 5X of the opening strip unwound from the roll in the conveying direction of the second sheet raw material 3X to a predetermined width to form the opening strip 5. However, the cutting mechanism is not limited to this configuration. The cutting mechanism may be a mechanism having a different configuration as long as it can form an opening strip 5 of a predetermined width.

The conveying/joining mechanism 101 includes, for example, a holding bar 102 and a joining bar 103. The holding bar 102 holds the opening strip 5 by sucking it along the longitudinal direction, and conveys the opening strip 5 from the cutting position to the arrangement position on the second sheet roll 3X. The joining bar 103 is arranged on the opposite side of the second sheet roll 3X at the arrangement position on the second sheet roll 3X of the opening strip 5. The joining bar 103 is, for example, a heat seal bar. This conveying/joining mechanism 101 holds the opening strip 5 formed by cutting with the holding bar 102, conveys it by moving the holding bar 102 (up and down in the example of FIG. 10), and arranges it on the inner surface of the second sheet roll 3X, and then forms the joint 50 by sandwiching the second sheet roll 3X and the opening strip 5 arranged on the inner surface between the holding bar 102 and the joining bar 103 and heat sealing it.

Here, one end of the joining bar 103 is shorter than the holding bar 102. Therefore, the portion of the opening strip 5 that is held by the holding bar 102 but not sandwiched between the joining bar 103 and the joining bar 102 is not joined to the second sheet roll 3X, and becomes the one end 5a and the non-jointed portion adjacent to the one end 5a.

However, the conveying and joining mechanism is not limited to these configurations. The conveying and joining mechanism may be a mechanism of other configurations as long as it can join the opening strip 5 to the inner surface of the second sheet original 3X while leaving one end 5a and the non-joined portion, that is, can join the opening strip 5 to the inner surface of the second sheet original 3X within a predetermined range from the first free piece 33 to the other end side of the opening strip 5.

In the third step, the second sheet original 3X is intermittently transported. Then, as shown in Figures 11 to 14, the external force application mechanisms 104, 105 for one opening strip 5A and the external force application mechanisms 104, 105 for the other opening strip 5B, which are arranged on the transport path, operate in synchronization with the intermittent transport of the second sheet original 3X, so that one end 5a of one opening strip 5A and one end 5a of the other opening strip 5B are each pushed out to the opposite side of the second sheet original 3X.

The external force application mechanism includes, for example, an air nozzle 104 (FIG. 13). This external force application mechanism bends the first free piece 33 to form an opening by blowing air toward the first free piece 33 and the portion of the opening strip 5 in the first free piece 33, and moves one end 5a of the opening strip 5 to the opposite side of the second sheet original 3X through this opening. Alternatively, the external force application mechanism includes, for example, a rod 105 (FIG. 14) that moves up and down. This external force application mechanism bends the first free piece 33 to form an opening by abutting the tip of the rod 105 against the first free piece 33 and the portion of the opening strip 5 in the first free piece 33, and further pushes the rod 105 in, and moves one end 5a of the opening strip 5 to the opposite side of the second sheet original 3X through this opening.

However, the external force application mechanism is not limited to these configurations. The external force application mechanism may be a mechanism having other configurations as long as it can move one end 5a of the opening strip 5 to the opposite side of the second sheet original 3X. For example, a suction mechanism or adsorption mechanism may be disposed on the opposite side of the second sheet original 3X, and the first free piece 33 may be sucked or adsorbed from the opposite side, thereby moving one end 5a of the opening strip 5 to the opposite side of the second sheet original 3X.

The second sheet raw roll 3X is manufactured in the above manner. The second sheet raw roll 3X is then wound into a roll and set in the bag making device. Alternatively, the second sheet raw roll 3X is continuously transported as it is manufactured by the bag making device, and then moves to a process of manufacturing food packaging bags 1 from the first sheet raw roll 2X and the second sheet raw roll 3X.

Except for the step of joining the covering piece 6 to the second sheet roll 3X, the steps of manufacturing the food packaging bag 1 are as described in, for example, JP 2005-219319 A, and are methods that have been used conventionally. Therefore, detailed explanations will not be given here. As shown in Figs. 15 and 16, the steps are as follows: iv) forming the top joint 11 (fourth step), v) arranging and joining the covering piece 6 to the outer surface of the second sheet roll 3X so as to cover the cut lines 32, 34 and the free pieces 33, 35 (fifth step), vi) forming the side joints 12 while separating the food packaging bags 1 individually (sixth step), and vii) forming the notches 14 (seventh step).

In the fifth step, the second sheet original 3X is intermittently transported. Then, a cutting/transporting/joining mechanism (not shown) for one covering piece 6A and a cutting/transporting/joining mechanism (not shown) for the other covering piece 6B, which are arranged on the transport path, operate in synchronization with the intermittent transport of the second sheet original 3X, so that the covering piece 6 is separated from the covering piece original, transported, and placed on the outer surface of the second sheet original 3X as shown in FIG. 16, and joined (joining portion 62). Here, as described above, the covering piece 6 is joined to the second sheet original 3X by the action of a coating agent (part coating agent) applied to the inner surface, as an example. Therefore, the covering piece 6 can be joined to the second sheet original 3X without fixing the first and second sheet originals 2X and 3X at the joint.

Through the above steps, the food packaging bag 1 is completed. Note that the step of joining the inner sheet 4 to the inner surface of the first sheet roll 2X is performed before overlapping the first sheet roll 2X and the second sheet roll 3X, although this step is not shown.

In this way, with the food packaging material 1 according to this embodiment, an opening means in which one end 5a of the opening strip 5 protrudes toward the outer surface of the food packaging material 1 to serve as a tab for opening (via the covering piece 6) can be realized with a simple configuration and a simple method.

In addition, in the food packaging material 1 according to this embodiment, the first cut line 32, which is the opening starting point for the first stage of the opening operation, and the second cut line 34, which is the opening starting point for the second stage of the opening operation, are covered and sealed with the covering piece 6. Therefore, according to the food packaging material 1 according to this embodiment, it is possible to impart high sealing properties to the opening means, and it is possible to effectively prevent foreign objects and the like from entering the inside, resulting in a food package that is excellent in terms of food hygiene.

In addition, in the food packaging material 1 according to this embodiment, the covering piece 6 is joined to the second sheet 3 by heat sealing. Therefore, the covering piece 6 is firmly joined to the first free piece 33 and one end 5a of the opening strip 5. This allows the food package to be reliably opened by opening the covering piece 6.

In addition, in the food packaging material 1 according to this embodiment, one end 5a of the opening strip 5 protrudes from the outer surface side of the second sheet 3, and this end 5a is picked up through the covering piece 6 to open it, i.e., the opening strip 5 is essentially directly pulled to open it. Therefore, according to the food packaging material 1 according to this embodiment, the food package can be opened properly and reliably by the first stage opening operation.

In the food packaging material 1 according to this embodiment, the second cut line 34, which is the opening starting point of the second stage opening operation, is a cut line that does not have a component in a direction that crosses the second direction diagonally at each end point 34a. More specifically, since the second cut line 34 is a semicircular arc, the tangent line at each end point 34a of the second cut line 34 is a line parallel to the first direction, a line perpendicular to the second direction, and a line that does not cross the second direction diagonally. Therefore, according to the food packaging material 1 according to this embodiment, the tearing of the second sheet 3 is not easily induced to the top joint 11 by the second stage opening operation, and the second sheet 3 is easily torn parallel to the top joint 11, so that the food package can be opened appropriately and reliably in a wide width from side to side.

In the food packaging material 1 according to this embodiment, the cut lines 32, 34 are formed in the bag body 10 at a location close to the top joint 11. The farther the cut lines 32, 34 are formed from the top joint 11, the greater the area that cannot be opened by the second stage opening operation. However, the closer the cut lines 32, 34 are formed to the top joint 11, the narrower this area becomes, improving the ease of removing food. In this case, the gripping portion 61 of the covering piece 6 overlaps with the top joint 11 and is positioned to extend beyond the top joint 11 into the header portion 15. Therefore, the gripping portion 61 of the covering piece 6 is slightly lifted and separated from the outer surface of the header portion 15, making it easier to grip. Alternatively, by warping the header portion 15, the gripping portion 61 of the covering piece 6 is sufficiently separated from the header portion 15, making it even easier to grip. This allows the opening operation to be performed smoothly.

The food packaging material according to the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention.

For example, in the above embodiment, one end 5a of the opening strip 5 protrudes from the first cut line 32 and is joined to the covering piece 6, so that the opening strip 5 is directly opened via the opening operation of the covering piece 6. However, the present invention is not limited to this. As shown in Figures 17 to 20, the opening strip 5 may not protrude from the first cut line 32, and the first free piece 33 may be opened via the opening operation of the covering piece 6, so that the opening strip 5 is indirectly opened.

The shapes and structures of the cut line and the free piece are not limited to those in the above embodiment. As long as the second cut line extends from the first cut line to the outside of the free piece and does not have a component that crosses the second direction obliquely at the end point, various shapes and structures of the cut line and the free piece can be adopted. As an example, the shapes and structures shown in Figures 21 and 22 can be adopted.

In the example shown in FIG. 21(a), the free piece 33 has a rectangular shape. In the examples shown in FIG. 21(a) and FIG. 21(b), a pair of second cut lines 34, 34 extend in the second direction from the end points 32a, 32a of the first cut line 32.

Figures 21(c) and 21(d) show a configuration in which a pair of second cut lines 34, 34 extend in the second direction from the side edges 33b, 33b of the first free piece 33.

Figures 21(e) and 21(f) show a configuration in which one second cut line 34 extends in the first direction from the tip edge 33a of the first free piece 33.

22(a) to (c) show a pair of second cut lines 34, 34 that extend obliquely from the tip edge 33a of the first free piece 33, and the ends are bent and extend in the second direction. The portion on one side of the midpoint of the first cut line 32 and the portion on the other side of the midpoint of the second cut line 34, and the portion on the other side of the midpoint of the first cut line 32 and the portion on one side of the midpoint of the second cut line 34 are each continuous, forming an X-shape overall.

Figure 22(d) shows a configuration in which a pair of second cut lines 34, 34 extend in the second direction from the tip edge 33a of the first free piece 33.

Figure 22(e) shows a configuration in which a pair of second cut lines 34, 34 extend in the first direction from both corners of the rectangular first free piece 33. The overall configuration has an H-shape.

The cut line is not limited to a full cut line. The cut line may be any line that tears when an external force is applied. For example, the cut line may be a half cut line or a perforation.

The opening strip is not limited to being made of a single member. For example, the opening strip may be made by joining a separate main body and one end together.

The opening means may also be provided on the first sheet rather than the second sheet.

The covering piece is not limited to being attached to the sheet by heat sealing. For example, the covering piece may be a so-called label that has an adhesive or bonding surface on its inner surface and can be peelably attached or adhered to the sheet.

Furthermore, a header portion is not essential for food packaging bags. For example, a food packaging bag may not have a header portion and may consist only of a bag body.

In addition, terms expressing shapes, parts or states such as "trapezoid", "rectangular", "rectangular", "arc", "semicircular", "straight line", "center", "end", "side", "coincident" and "parallel" in this invention include not only the term itself, but also the concept of "approximately" which means close to or similar to it.

Furthermore, the food to be packaged is not limited to sandwiches. The food may be in any form that can be accommodated in a food packaging bag. For example, the food may be bread, cake, rice-based processed foods such as rice balls, etc. In this way, the type of food is not limited.

The sheets are not limited to being made of a single plastic sheet. For example, the sheets may be made of other materials, such as paper or paper-like sheets. The sheets may also be made of multiple sheets, such as two sheets joined at their ends to form a single sheet, or three sheets joined at their ends in sequence to form a single sheet. In this case, the sheets may be made of different materials. For example, some of the sheets may be made of paper or paper-like sheets instead of plastic sheets.

In the above embodiment, the sheet 2 is a polypropylene sheet. Here, the polypropylene sheet is not only a sheet of 100% pure polypropylene, but also a sheet that contains polypropylene as the main component and other components (for example, other resin components such as polyethylene).

The food packaging material according to the present invention is characterized in that it has a second cut line that extends from the first cut line to the outside of the free piece and does not have a component that crosses the second direction obliquely at the end point. However, in the above embodiment, it is possible to identify another invention that does not depend on the presence or absence of this second cut line. The content is as follows.
In conventional food packaging bags for packaging foods such as sandwiches, which have a triangular (mainly right-angled triangle) or similar side shape and are finished into a three-dimensional shape of a specified thickness or width, the opening means generally has a structure in which an inverted U-shaped cut line is formed in the sheet, an opening tab is formed with the cut line as its outline, and an opening strip such as cutting tape is joined to the inner surface of the sheet from the tab to the other end of the sheet.
However, due to the influence of the precision of the manufacturing equipment for food packaging bags (variation in bonding conditions, etc.), the sheet and the opening strip may not be bonded sufficiently. In such food packaging bags, when the tab is pulled down to open the bag, the tab or a part of the sheet following the tab may peel off from the opening strip, and only the sheet may be pulled, making it impossible to open the bag properly.
From the viewpoint of solving this problem, the food packaging bag described in the Registered Utility Model Publication No. 3072028 has one end of a strip for opening that protrudes from the outer surface of the sheet and is opened by pinching this end, and since the strip for opening is opened by directly pulling it, it can be opened properly and reliably. In this respect, the food packaging bag described in this document can be said to be superior to conventional food packaging bags.
However, in the food packaging bag described in the above document, it is unclear what kind of processing is applied to the sheet to allow one end of the opening strip to protrude from the outer surface side of the sheet. Also, in the food packaging bag described in the above document, it is unclear what method is used to allow one end of the opening strip to protrude from the outer surface side of the sheet. For this reason, it is impossible to mass-produce food packaging bags that are consumed in large quantities.
In view of the above circumstances, there is a need for a method for manufacturing food packaging bags and packaging sheets that are easy to mass-produce and have an opening means in which one end of an opening strip protrudes and serves as a tab for opening.
Another invention of this food packaging bag is:
"A pair of sheets, each having a shape wider at one end than at the other end, are overlapped, and the bag body is sealed on three sides by the top joint at one end and the side joints at both sides, with the other end being an opening.
One sheet is
a free piece formed by forming a cut line at a predetermined portion of the bag body, the free piece opening when bent to form an opening;
a strip for opening disposed on the inner surface of the sheet and extending from the free piece to the other end side of the sheet, the strip for opening having one end protruding from the cut line to the outer surface side of the sheet;
and a covering piece that is disposed on the outer surface of the sheet and is joined to the sheet while covering the cut line and the free piece (and one end of the opening strip, if necessary) from the outer surface side of the sheet."
The invention of the manufacturing method of the packaging sheet is as follows:
"A method for manufacturing a packaging sheet having a strip for opening extending in a predetermined direction on one side of the sheet,
forming score lines in the sheet and forming free pieces that open when bent to form openings;
A step of arranging a strip for opening on one surface of the sheet such that a portion of the strip for opening that is inward from one end of the strip overlaps the free piece, and joining the strip for opening to the sheet within a predetermined range from the free piece to the other end of the strip for opening;
a step of applying an external force to the detachable piece to move one end of the opening strip to the other side of the sheet through an opening formed by the detachable piece and protruding from the cut line to the other side of the sheet;
and placing a covering piece on the other side of the sheet so as to cover the cut line and the free piece (and one end of the opening strip, if necessary), and joining the covering piece to the sheet."

The invention of the method for manufacturing a packaging sheet, like the other invention of the food packaging bag, is not limited to the above embodiment. Like the other invention of the food packaging bag, the invention of the method for manufacturing a packaging sheet can be modified in various ways without departing from the gist of the invention.

For example, packaging sheets are not limited to those used for a specific packaging form. Packaging sheets include all those used for various packaging forms, such as the outer sheet of food packaging material that packages rice balls and seaweed sheets separately, pillow packaging sheets, and sheets used in general bags such as flat bags and gusseted bags.

The object to be packaged is not limited to food. The object to be packaged may be something other than food.

1, 1A, 1B...food packaging bag, 10...bag body, 11, 11A, 11B...top joint, 12, 12A, 12B...side joint, 13...opening, 14, 14A...notch, 15...header, 2...first sheet (front sheet), 2X...first sheet roll, 20...body, 21...tip, 3...second sheet (back sheet), 3X...second sheet roll, 30...body, 31...tip, 3 2, 32A, 32B...first cut line, 32a...end point, 33, 33A, 33B...first free piece, 33a...tip edge, 33b...side edge, 34, 34A, 34B...second cut line, 34a...end point, 35, 35A, 35B...second free piece, 36...third free piece, 37...fourth free piece, 38...divided end, 4...inner sheet, 40...joint, 5, 5A, 5B...opening strip, 5X...opening strip The sheet raw material, 5a... one end (picking piece), 5b... side edge, 50, 50A, 50B... joint portion, 50a... leading edge, 6, 6A, 6B... covering piece, 60... main body portion, 61, 61A, 61B... picking piece, 62, 62A, 62B... joint portion, 62a... edge, 100... cutting mechanism, 101... conveying/joining mechanism, 102... holding bar, 103... joining bar, 104... air nozzle (external force application mechanism), 10 5...rod (external force application mechanism), L1...center line of the opening strip 5 and the first free piece 33 in the width direction, L2...center line of the joint 50 in the width direction, G1...distance between the tip edge 50a of the joint 50 and the tip edge 33a of the first free piece 33 (width of the non-jointed part), G2...distance between the side edge 5b of the opening strip 5 and the end point 32a of the first cut line 32 (width of the gap), S1...amount of deviation between the center line L1 and the center line L2

Claims (2)

a bag body including a pair of overlapping sheets each having a shape in which one end side is wider than one end side in a first direction, the bag body being sealed on three sides by a top joint part at one end side and side joint parts at both side edges, and the other end side being an opening,
One sheet is
At least, the film has a tear directionality in a first direction or a second direction perpendicular to the first direction;
a first cut line having both ends directed toward the other end of the sheet and forming a free piece that is convex toward one end of the sheet on the inside;
a second cut line extending from both side edges (excluding both end points of the first cut line) of the free piece to the outside of the free piece in a second direction and not having a component in a direction obliquely intersecting the second direction at the end points;
A food packaging bag comprising: an opening strip disposed on the inner surface of the sheet and extending from the free piece to the other end side of the sheet. a bag body including a pair of overlapping sheets each having a shape in which one end side is wider than one end side in a first direction, the bag body being sealed on three sides by a top joint part at one end side and side joint parts at both side edges, and the other end side being an opening,
One sheet is
At least, the film has a tear directionality in a first direction or a second direction perpendicular to the first direction;
a first cut line having both ends directed toward the other end of the sheet and forming a free piece that is convex toward one end of the sheet on the inside;
a second cut line extending from a tip edge of the free piece to an outside of the free piece in a first direction and not having a component in a direction obliquely intersecting with the second direction at an end point of the first cut line;
A food packaging bag comprising: an opening strip disposed on the inner surface of the sheet and extending from the free piece to the other end side of the sheet.

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