JP7487384B2 - Method for manufacturing packaging sheet - Google Patents

Description

The present invention relates to a method for manufacturing a packaging sheet.

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. Food packaging bags for packaging such foods are generally as shown in Figures 16 and 17(a).

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.

In the second sheet 3' in the header section 15', a cut line 32', for example, in an inverted U shape, is formed, and an opening tab 33' is formed with the cut line 32' as an outline. An opening strip 5' such as a cutting tape is joined to the inner surface of the second sheet 3' from the tab 33' to the other end of the second sheet 3'.

When eating food packaged in the food packaging bag 1', the tab 33' is pinched and pulled down as shown in FIG. 17(b). This pulls the opening strip 5', forming a tear-open section in the second sheet 3', and the food can be removed from this tear-open section.

However, due to the influence of the precision of the manufacturing equipment for the food packaging bag 1' (variation in bonding conditions, etc.), the second sheet 3' and the opening strip 5' may not be bonded sufficiently. In such a food packaging bag 1', when the tab 33' is pulled down to open it, the tab 33' or the part of the second sheet 3' following it may peel off from the opening strip 5', and only the second sheet 3' may be pulled, making it impossible to open properly. This problem becomes more pronounced as the bonding strength of the top joint 11' increases. Therefore, in order to prevent the bonding strength of the top joint 11' from becoming too strong, it has been conventional to apply a part coating agent to the bonding surface prior to bonding.

From the perspective of resolving these problems, the food packaging bag described in Patent Document 1 has one end of the opening strip that protrudes toward the outer surface of the header, and is opened by pinching this end. Since the opening strip is opened by directly pulling it, the bag can be opened properly and reliably. In this respect, the food packaging bag described in Patent Document 1 is superior to the conventional food packaging bag 1' described above.

Registered Utility Model No. 3072028

However, it is unclear what processing is applied to the sheet of the food packaging bag described in Patent Document 1 to allow one end of the opening strip to protrude from the outer surface of the sheet. Also, it is unclear what method is used to allow one end of the opening strip to protrude from the outer surface of the sheet of the food packaging bag described in Patent Document 1. For this reason, it is impossible to mass-produce food packaging bags that will be consumed in large quantities.

The present invention was made in consideration of these circumstances, and aims to provide a method for manufacturing a packaging sheet that is easy to mass-produce, in which one end of the opening strip protrudes and is provided with an opening means that serves as a tab for opening.

The method for producing a packaging sheet according to the present invention comprises the steps of:
A method for manufacturing a packaging sheet having an opening strip extending in a predetermined direction on one side of the sheet, comprising:
forming score lines in the sheet and forming free pieces that open when bent to form openings;
A step of arranging the opening strip on one surface of the sheet such that a portion of the opening strip that is inside the one end of the opening strip overlaps the free piece, and fixing the portion of the opening strip other than the one end of the opening strip to be aligned along the one surface of the sheet;
a step of applying an external force toward the detachable piece from a direction intersecting the surface of the sheet , thereby moving one end of the opening strip to the other surface side of the sheet through an opening formed by the detachable piece, and causing the strip to protrude from the cut line to the other surface side of the sheet.
Do this in this order.

Further, a method for producing a packaging sheet according to another aspect of the present invention includes the steps of:
A method for manufacturing a packaging sheet having an opening strip extending in a predetermined direction on one side of the sheet, comprising:
forming a score line in the sheet;
A step of arranging a strip for opening on one surface of a sheet such that a portion of the strip for opening that is inside one end of the strip for opening overlaps the cut line, and fixing a portion of the strip for opening other than the one end of the strip for opening along the one surface of the sheet;
a step of applying an external force toward the cut line from a direction intersecting the surface of the sheet , thereby moving one end of the opening strip to the other surface side of the sheet through an opening formed by the cut line, and protruding from the cut line to the other surface side of the sheet.
Do this in this order.

Further, a further method for producing a packaging sheet according to the present invention comprises the steps of:
A method for manufacturing a packaging sheet having an opening strip extending in a predetermined direction on one side of the sheet, comprising:
forming an aperture in the sheet;
A step of arranging a strip for opening on one surface of a sheet such that a portion of the strip for opening that is inside one end of the strip for opening overlaps the opening, and fixing a portion of the strip for opening other than the one end of the strip for opening along the one surface of the sheet;
a step of applying an external force toward the opening from a direction intersecting the surface of the sheet , thereby moving one end of the opening strip toward the other surface of the sheet through the opening and protruding from the opening to the other surface of the sheet ;
Do this in that order.

In these inventions, one example of the means for applying an external force is a means for blowing air from an air nozzle.

Alternatively, another example of the means for applying an external force is to apply the tip of a rod and push the rod in.

Alternatively, the means for applying an external force may be, as yet another example, a means for adsorption or suction.

As described above, the method for manufacturing a packaging sheet according to the present invention can achieve excellent mass production with a simple configuration and simple method.

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 a perspective view of a food package packaged in the food packaging bag, as viewed from the rear side, and Fig. 5(b) is a perspective view of the food package being opened. FIG. 6 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. 7 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. 8(a) and (b) are explanatory diagrams of the configuration of an apparatus for carrying out the steps of FIG. FIG. 9 is an explanatory diagram of the manufacturing process of the food packaging bag, specifically, an explanatory diagram of a process of protruding one end of the opening strip from the cut line to the opposite surface side of the second raw sheet. FIG. 10 is an explanatory diagram seen from the opposite side to FIG. 11A to 11C are explanatory diagrams of the configuration of an apparatus for carrying out the process of FIG. 12(a) to (c) are explanatory diagrams of another apparatus configuration for carrying out the process of FIG. FIG. 13 is an explanatory diagram of the manufacturing process of the food packaging bag, illustrating each step from the first and second raw sheet rolls to the final completion of the food packaging bag. 14(a) to (d) are enlarged views of main parts of food packaging bags according to different embodiments. 15(a) to (d) are enlarged views of main parts of a food packaging bag according to still another embodiment. FIG. 16 is a rear view of a conventional food packaging bag. Fig. 17(a) is a perspective view of a food package wrapped in the food packaging bag, as viewed from the back side, and Fig. 17(b) is a perspective view of the food package being opened.

Below, a food packaging bag used to package sandwiches will be described as one embodiment of the food packaging bag according to the present invention with reference to Figures 1 to 13.

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 thermal adhesive properties, such as polyethylene or polypropylene. The first sheet 2 is configured with a body 20 and a tip 21 (the protruding piece). The body 20 has a shape that gradually becomes wider from one end to the other end. 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 thermal adhesive properties, such as polyethylene or polypropylene. The second sheet 3 is composed of a body 30 and a tip 31 (the protruding piece). The body 30 has a shape that gradually becomes wider from one end to the other end. The tip 31 has a narrow shape that extends from one end of the body 30.

In this embodiment, the body 20, 30 is trapezoidal, and the tip 21, 31 is rectangular. Therefore, one end of the body 20, 30 (and the other end of the tip 21, 31 that coincides with it) is linear and perpendicular to the direction from one end side to the other end side of the sheets 2, 3 (hereinafter referred to as the "longitudinal direction"). In other words, one end of the body 20, 30 is linear and parallel to the direction perpendicular to the longitudinal direction (hereinafter referred to as the "width direction"). Both side edges of the body 20, 30 are linear and inclined with respect to the longitudinal direction. Both side edges of the tip 21, 31 are linear and parallel to the longitudinal direction. However, the other end side of both side edges of the body 20, 30 is missing due to the notch 14. As a result, the other end side of the body 20, 30 is narrowed by the amount of the notch 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 longitudinal 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, with a point seal or the like (joint 22), 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 cut line 32 is formed in the second sheet 3 in the header section 15. The cut line 32 forms a free piece 33 in the second sheet 3 in the header section 15. The cut line 32 has both end points 32a, 32a that are close to the top joint section 11. The free piece 33 has the cut line 32 as its outline, the area between the both end points 32a, 32a as a fixed end, and one end as a free end, and when bent at the fixed end side, it opens to form an opening. In this embodiment, the cut line 32 is formed in an inverted U-shape. As a result, the free piece 33 has one end edge 33a along the width direction and a pair of left and right side edges 33b, 33b along the length direction, and becomes an upward tongue piece.

On the inner surface of the second sheet 3, an opening strip 5 is provided from the free piece 33 to the other end of the second sheet 3. The opening strip 5 is provided, for example, along the longitudinal direction at the center of the width of the second sheet 3. The opening strip 5 is joined to the inner surface of the second sheet 3 by heat sealing, adhesion, or the like (joint 34). 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 adhesion properties such as biaxially oriented polyester, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), biaxially oriented polypropylene (OPP), etc.

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 cut line 32 toward the outer surface of the second sheet 3, forming a gripping piece for opening. As a result, when the one end 5a of the opening strip 5 is gripped and pulled down, the opening strip 5 is pulled, and the second sheet 3 is cut at a predetermined width from the free piece 33 as the opening starting point, and a cut-open 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 grip. Conversely, if it is long, it is likely 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.

As shown in FIG. 4(b), the opening strip 5 is also joined to the free piece 33 and is integrated with the free piece 33. However, the opening strip 5 is not joined to one end edge 33a of the free piece 33. Therefore, a non-jointed portion of width G1 is interposed between one end edge 34a of the joint portion 34 and one end edge 33a of the 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 cut line 32 due to the influence of the precision of the manufacturing device for the food packaging bag 1 (such as 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 cut line 32 to the outer surface side of the second sheet 3. On the other hand, if the width G1 is large, the free piece 33 will be able to be picked up, and there is a concern that an erroneous opening operation will be performed by picking up this part to open it. In this case, the opening strip 5 will naturally not be used, and only the second sheet 3 will be 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, to allow for a margin of error in manufacturing.

The width of the opening strip 5 is smaller than the width of the fixed end of the free piece 33 (i.e., the distance between both ends 32a, 32a of the 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 free piece 33 or each end point 32a of the 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 cut line 32 and the one end 5a will not be able to protrude from the 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 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, as a fluctuation range for manufacturing errors.

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 sheet piece sticking out from the bottom surface of the food) is folded appropriately, the opening 13 is closed, a label or tape is attached, and the opening 13 is sealed. This completes the food package shown in FIG. 5(a). In this food package, one end 5a of the opening strip 5 has the free piece 33 as a fixed end and one end side as a free end, and protrudes from the cut line 32 to the outer surface side of the second sheet 3 in the header portion 15. On the other hand, the other part of the opening strip 5 runs from the free piece 33 along the inner surface of the second sheet 3.

When eating food, as shown in FIG. 5(b), one end 5a of the protruding opening strip 5 is picked up and pulled down. This pulls the opening strip 5, forming a tear-open section in the second sheet 3, and food can be removed from this tear-open section. In the food package, one end 5a of the opening strip 5 is slightly separated from the outer surface of the header section 15, making it easier to pick up. Alternatively, by bending the header section 15, one end 5a of the opening strip 5 is sufficiently separated from the header section 15, making it even easier to pick up. This allows for a smooth opening operation.

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 from the outer surface of the second sheet 3 and serves as a tab for opening, as shown in Figs. 6 to 12, 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 Fig. 13.

Because of its shape, this type of trapezoidal food packaging bag 1 is manufactured so that it is oriented transversely to the conveying direction of the sheet raw material 2X, 3X and the orientation is alternately reversed. That is, food packaging bags 1 with an opening 13 formed on one side in the width direction intersecting with the conveying direction of the sheet raw material 2X, 3X and a header portion 15 formed on the other side in the width direction are manufactured alternately, and food packaging bags 1 with an opening 13 formed on the other side in the width direction and a header portion 15 formed on one side in 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 referred to as "one" and has "A" added after the reference number, and the configuration related to the latter food packaging bag 1 is referred to as "the other" and has "B" added after the reference number.

The process for manufacturing the second sheet raw roll 3X is one embodiment of the method for manufacturing a packaging sheet and a method for manufacturing a packaging sheet raw roll according to the present invention. The process includes: i) a process for forming a cut line 32 in the second sheet raw roll 3X as shown in FIG. 6, more specifically, a process for forming the cut line 32 in the second sheet raw roll 3X and forming a free piece 33 by forming the cut line 32 (first process); ii) a process for disposing the opening strip 5 on the inner surface of the second sheet raw roll 3X so that the part inside one end 5a of the opening strip 5 overlaps the free piece 33, and a process for disposing the opening strip 5 on the inner surface of the second sheet raw roll 3X so that the part inside one end 5a of the opening strip 5 overlaps the free piece 33 within a predetermined range from the free piece 33 to the other end side of the opening strip 5, as shown in FIG. 7 and FIG. iii) as shown in Figures 9 to 12, by applying an external force toward the detachable piece 33, more specifically, toward the portion of the opening strip 5 in the detachable 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 detachable piece 33, and protrudes from the 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 cut line 32A and a cutting mechanism (not shown) for the other cut line 32B, which are arranged on the transport path, operate in synchronization with the intermittent transport of the second sheet roll 3X, thereby forming one cut line 32A and the other cut line 32B, as shown in FIG. 6.

As an example, the cutting mechanism includes a receiving roller and a tool. This cutting mechanism forms a cut line 32 in the second sheet raw material 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 is capable of forming a cut line 32 in the second sheet raw material 3X.

In the second step, the second sheet original 3X is intermittently transported. Then, as shown in FIG. 7 and FIG. 8, 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 34A, 34B).

As an example, the cutting mechanism 100 includes a pair of cutting blades. This cutting mechanism 100 cuts the sheet material 5X of the opening strip, which is unwound from the roll in the conveying direction of the sheet material 2X, 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. 8), and arranges it on the inner surface of the second sheet roll 3X. Then, the holding bar 102 and the joining bar 103 sandwich the second sheet roll 3X and the opening strip 5 arranged on the inner surface and heat seal it to form the joint 34.

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 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 9 to 12, 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. 11). This external force application mechanism bends the detached piece 33 to form an opening by blowing air toward the detached piece 33 and the portion of the opening strip 5 in the detached 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. 12) that moves up and down. This external force application mechanism bends the detached piece 33 to form an opening by putting the tip of the rod 105 against the detached piece 33 and the portion of the opening strip 5 in the detached piece 33, and further pushing 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 loose 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.

The process for manufacturing the food packaging bag 1 is as described in, for example, JP 2005-219319 A, and is a method that has been used for a long time. Therefore, it will not be described in detail here. As shown in FIG. 13, the process includes overlapping the first sheet raw roll 2X and the second sheet raw roll 3X with their inner faces facing each other, and transporting them intermittently in this state, while iv) forming the top joint 11, v) forming the side joint 12 and separating the food packaging bag 1 individually, and vi) forming the cutout 14. Through these steps, the food packaging bag 1 is completed. Note that the process for joining the inner sheet 4 to the inner face of the first sheet raw roll 2X is performed before overlapping the first sheet raw roll 2X and the second sheet raw roll 3X, although this is not shown.

In this way, according to the present embodiment, the method for manufacturing the second sheet roll 3X in which one end 5a of the opening strip 5 protrudes toward the outer surface side of the second sheet 3 and is equipped with an opening means that serves as a tab for opening, can achieve excellent mass productivity with a simple configuration and method.

In addition, the direction in which one end 5a of the opening strip 5 extends is the same as the direction in which the free piece 33 extends (both are upwardly convex). Therefore, one end 5a of the opening strip 5 can be reliably moved to the opposite side of the second sheet roll 3X with a small force.

The present invention is not limited to the above embodiment. Various modifications of the present invention are possible without departing from the spirit of the present invention.

The shapes and structures of the cut lines and free pieces are not limited to those in the above embodiment. For example, the shapes and structures of the cut lines and free pieces may be as shown in Figures 14 and 15.

Figure 14(a) shows an example in which an indication 50 that can be identified from the surrounding area is applied to one end 5a of the opening string 5. Normally, the opening string 5 is transparent. Therefore, the end 5a is not very noticeable if left as is. It is possible that some product purchasers have difficulty recognizing that this is a tab for opening. Therefore, by applying the indication 50 by printing or the like to the end 5a of the opening string 5, any product purchaser can easily recognize that it is a tab for opening.

The display unit may be, in addition to or instead of the display unit 50, which is made up of information indicating that it is a tab for opening, a display unit 51, which is made up of a simple color or pattern that can be distinguished from the surrounding area, as shown in FIG. 14(b).

The one shown in Fig. 14(c) has a π-shaped cut line 32, that is, a cut line 32 consisting of a line (horizontal line) 32b along the width direction that intersects with the longitudinal direction, and left and right lines (vertical lines) 32c, 32c extending along the longitudinal direction from a position inside both end points of line 32b. With this configuration, after opening in the vertical direction (longitudinal direction) by holding one end 5a of the opening strip 5, cut lines 32d, 32d facing outward in the width direction are formed in the header portion 15. Therefore, the remaining second sheet 3 after opening can be opened left and right to enlarge the divided open portion, making it easier to remove food.

The one shown in FIG. 14(d) has an X-shaped cut line 32 formed by two diagonal cut lines 32e, 32e crossing each other. Even with this configuration, cut lines 32f, 32f facing outward in the width direction are formed in the header portion 15 after opening. Therefore, the remaining second sheet 3 after opening can be opened wide to the left and right.

Figure 15(a) shows an H-shaped cut line 32, that is, a cut line 32 consisting of a line (horizontal line) 32g along the width direction that intersects with the longitudinal direction, and left and right lines (vertical lines) 32h, 32h extending along both longitudinal directions from both end points of line 32g. With this configuration, in addition to the upward free piece 33, a downward free piece 35 can also be formed so as to face this free piece 33.

Figure 15(b) shows a downward cut line 32, i.e., a cut line 32 formed such that the extension direction of one end 5a of the opening strip 5 is opposite to the extension direction of the free piece 35.

The cut line may be a straight or slightly curved line, such as a line along the width direction that intersects with the longitudinal direction (horizontal line) or a line that is inclined with respect to the width direction.

In addition, the structure for enabling one end 5a of the opening strip 5 to be moved to the opposite side of the second sheet 3 may be an opening 36 as shown in FIG. 15(c) instead of a combination of a cut line 32 and a free piece 33. Even if an opening 36 is used, the device and method for moving one end 5a of the opening strip 5 to the opposite side of the second sheet 3 are basically the same as those described above.

The joint 34 between the second sheet 3 and the opening strip 5 may be formed so that their centers coincide, as shown in FIG. 15(d). The joint may be formed over the entire width of the opening strip 5. The joint may be formed only on both side edges in the width direction of the opening strip 5. It is not essential that the joint be formed all the way to the other end of the opening strip 5. What is important is that the opening strip 5 does not peel off from the second sheet 3.

Furthermore, the joint is not limited to being formed continuously along the longitudinal direction. For example, the joint may be made of point seals applied at appropriate locations, including at the free pieces 33.

The cut line is not limited to a full cut line. The cut line may be any line that breaks when an external force is applied by the external force application mechanism. 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 2 instead of the second sheet 3.

In addition, terms expressing shapes, parts or states such as "trapezoidal", "rectangular", "rectangular", "straight line", "center", "end", "side", "coincident" and "parallel" in this invention include not only the term itself, but also the concept of "approximately" meaning 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.

Furthermore, the manufacturing method of the packaging sheet and the manufacturing method of the raw packaging sheet roll are not limited to the above embodiment.

In the above embodiment, a step (joining step) of joining the opening strip 5 to one side of the sheet (original web) is carried out prior to a step (protruding step) of protruding one end 5a of the opening strip 5 from the cut line 32 or opening 36 to the other side of the sheet (original web). However, the joining step may be carried out after the protruding step. In this case, it is preferable to carry out a step (temporary fixing step) of temporarily fixing the opening strip arranged on one side of the sheet (original web) to one side of the sheet (original web) prior to the protruding step so that the opening strip does not shift position relative to the sheet in the protruding step. The temporary fixing step is carried out, for example, by using an adhesive, a pressure sensitive adhesive, clamping, pressure, crimping, weak bonding (weak heat sealing), etc.

The packaging sheet is not limited to being used for a specific packaging form. The packaging sheet covers all sheets 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 for 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.

Furthermore, the packaging sheet is not limited to being a continuous long sheet. For example, the packaging sheet may be in the form of a single sheet.

The packaging sheet is not limited to being made of a single plastic sheet. For example, the packaging sheet may be a sheet of other material, such as paper or a paper-like sheet. The packaging sheet may also be formed from 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 materials of the sheets may be different. For example, some of the sheets may be paper or a paper-like sheet instead of a plastic sheet.

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, 22...joint, 3...second sheet (back sheet), 3X...second sheet roll, 30...body, 31...tip, 32, 32A, 32B...slit line, 32a...end point, 32b-32h...slit line, 33, 33A, 33B...free piece, 33a...one end edge, 33b...side edge, 34, 34A, 34B...joint, 34a...one end edge, 35...free piece, 36...opening, 4...inner sheet , 5, 5A, 5B... Opening strip, 5X... Sheet roll of opening strip, 5a... One end (pinch), 5b... Side edge, 50... Display, 51... Display, 100... Cutting mechanism, 101... Conveying and joining mechanism, 102... Holding bar, 103... Joining bar, 104... Air nozzle (external force application mechanism), 105... Rod (external force application mechanism), L1... Center line of opening strip 5 and detached piece 33 in the width direction, L2... Center line of joining part 34 in the width direction, G1... Distance between one end edge 34a of joining part 34 and one end edge 33a of detached piece 33 (width of non-joined part), G2... Distance between side edge 5b of opening strip 5 and end point 32a of cut line 32 (width of gap), S1... Displacement between center line L1 and center line L2

Claims (4)

A method for manufacturing a packaging sheet having an opening strip extending in a predetermined direction on one side of the sheet, comprising:
forming score lines in the sheet and forming free pieces that open when bent to form openings;
A step of arranging the opening strip on one surface of the sheet such that a portion of the opening strip that is inside the one end of the opening strip overlaps the free piece, and fixing the portion of the opening strip other than the one end of the opening strip to be aligned along the one surface of the sheet;
a step of applying an external force toward the detachable piece from a direction intersecting the surface of the sheet , thereby moving one end of the opening strip to the other surface side of the sheet through an opening formed by the detachable piece, and causing the strip to protrude from the cut line to the other surface side of the sheet.
A method for producing a packaging sheet, characterized in that the steps are carried out in the above order . A method for manufacturing a packaging sheet having an opening strip extending in a predetermined direction on one side of the sheet, comprising:
forming a score line in the sheet;
A step of arranging a strip for opening on one surface of a sheet such that a portion of the strip for opening that is inside one end of the strip for opening overlaps the cut line, and fixing a portion of the strip for opening other than the one end of the strip for opening along the one surface of the sheet;
a step of applying an external force toward the cut line from a direction intersecting the surface of the sheet , thereby moving one end of the opening strip to the other surface side of the sheet through an opening formed by the cut line, and protruding from the cut line to the other surface side of the sheet.
A method for producing a packaging sheet, characterized in that the steps are carried out in the above order . A method for manufacturing a packaging sheet having an opening strip extending in a predetermined direction on one side of the sheet, comprising:
forming an aperture in the sheet;
A step of arranging a strip for opening on one surface of a sheet such that a portion of the strip for opening that is inside one end of the strip for opening overlaps the opening, and fixing a portion of the strip for opening other than the one end of the strip for opening along the one surface of the sheet;
a step of applying an external force toward the opening from a direction intersecting the surface of the sheet , thereby moving one end of the opening strip toward the other surface of the sheet through the opening and protruding from the opening to the other surface of the sheet ;
A method for producing a packaging sheet, characterized in that the steps are carried out in the above order . 4. The method for producing a packaging sheet according to claim 1, wherein the means for applying an external force is any one of a means for blowing air from an air nozzle, a means for pressing the tip of a rod into the sheet, and a means for adsorbing or suctioning the sheet.

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