CN111936305A

CN111936305A - Method for producing packaging sheet, method for producing packaging sheet blank, and packaging bag for food

Info

Publication number: CN111936305A
Application number: CN201980003065.2A
Authority: CN
Inventors: 神谷知毅
Original assignee: Howa Sangyo Co Ltd
Current assignee: Howa Sangyo Co Ltd
Priority date: 2019-02-19
Filing date: 2019-09-05
Publication date: 2020-11-13
Anticipated expiration: 2039-09-05
Also published as: JP2023106593A; TW202103906A; CN111936305B; JP2020132275A; TWI808291B; JP7290595B2; JP7487384B2; WO2020170483A1

Abstract

In order to improve the mass productivity of a packaging sheet having an unsealing mechanism which protrudes one end (5a) of an unsealing strip (5) and serves as a pinching piece for unsealing, a method for manufacturing a packaging sheet of the present invention includes: a step of forming a free sheet (33) which is opened when bent and forms an opening by forming a cut-in line (32) on the sheet (3); a step in which the opening strip (5) is disposed on one surface of the sheet (3) so that a portion of the opening strip (5) that is located further inward than the one end (5a) of the opening strip (5) overlaps the free sheet (33), and the opening strip (5) is joined to the one surface of the sheet (3) within a predetermined range from the free sheet (33) to the other end of the opening strip (5); and a step of moving the one end portion (5a) of the unsealing strip (5) toward the other surface side of the sheet (3) through the opening formed by the release sheet (33) by applying an external force to the release sheet (33) to cause the one end portion (5a) of the unsealing strip (5) to protrude from the cut-in line (32) toward the other surface side of the sheet (3).

Description

Method for producing packaging sheet, method for producing packaging sheet blank, and packaging bag for food

Technical Field

The present invention relates to a method for producing a packaging sheet, a method for producing a packaging sheet blank, and a food packaging bag.

Background

There are food products such as sandwiches processed into a three-dimensional shape having a side surface in a triangular shape (mainly a right-angled triangular shape) or a shape similar thereto and having a predetermined thickness or width. A food packaging bag for packaging such food is generally shown in fig. 16 and 17 (a).

The food packaging bag 1 ' has a bag body 10 ' and a head 15 '. The bag body 10 ' is configured such that a pair of sheets 2 ' and 3 ' having a shape wider at one end side than at the other end side are overlapped, three sides are sealed by a top joining portion 11 ' at one end side and side joining portions 12 ' and 12 ' at both side edges, and the other end side becomes an opening portion 13 '. The head portion 15 'is configured to integrally join the projecting pieces of the respective sheets 2', 3 'projecting from the top joining portion 11' to each other at appropriate positions.

A cut line 32 ' in an inverted U shape, for example, is formed in the second sheet 3 ' of the head portion 15 ', and a tab 33 ' for opening having the cut line 32 ' as a contour line is formed. An opening strip 5 'such as a tearable 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 the food packaged in the food packaging bag 1 'is consumed, the grip piece 33' is pinched and pulled downward as shown in fig. 17 (b). Then, the opening strip 5 'is pulled to form a cut-open portion in the second sheet 3', and the food can be taken out from the cut-open portion.

However, the second sheet 3 ' and the opening strip 5 ' may not be sufficiently joined due to the influence of the accuracy of the manufacturing apparatus of the food packaging bag 1 ' (variations in joining conditions, etc.). In the food packaging bag 1 'of this type, when the tab piece 33' is pulled downward at the time of opening, the tab piece 33 'or a part of the second sheet 3' continuous therewith is peeled off from the opening strip 5 ', and only the second sheet 3' is pulled, which causes a problem that the bag cannot be opened properly. Moreover, the stronger the joining strength of the top joining portion 11', the more remarkable the problem becomes. Therefore, it is conventional to coat the joint surfaces with a partial coating agent before joining so that the joining strength of the top joint portion 11' is not excessively strong.

In view of solving these problems, the food packaging bag described in patent document 1 is opened appropriately and reliably because one end portion of the opening strip protrudes to the outer surface side of the head portion, and the opening strip is opened by pinching the one end portion and pulling the opening strip directly to open the bag. In this regard, the food packaging bag described in patent document 1 is superior to the conventional food packaging bag 1'.

Documents of the prior art

Patent document

Patent document 1: utility model No. 3072028

Disclosure of Invention

Problems to be solved by the invention

However, in the packaging bag for food described in patent document 1, it is not clear what kind of processing is performed on the sheet material, and it is possible to project the one end portion of the opening strip toward the outer surface side of the sheet material. In the food packaging bag described in patent document 1, it is not clear how the one end portion of the opening strip is projected to the outer surface side of the sheet. Therefore, it is impossible to mass-produce a large amount of consumed food packaging bags.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for producing a packaging sheet, a method for producing a packaging sheet blank, and a packaging bag for food, each of which has an opening mechanism having an opening strip with one end protruding to serve as a tab for opening, and which is excellent in mass productivity.

Means for solving the problems

The method for manufacturing a packaging sheet of the present invention is a method for manufacturing a packaging sheet having an opening strip extending in a predetermined direction on one surface of the sheet,

the method for manufacturing the sheet for packaging comprises the following steps:

forming a cut line in the sheet material, and forming a free sheet that opens when bent to form an opening by forming the cut line;

a step of arranging the opening strip on one surface of the sheet so that a portion of the opening strip on the inner side of one end portion of the opening strip overlaps the free sheet, and bonding the opening strip to the one surface of the sheet within a predetermined range from the free sheet to the other end side of the opening strip; and

and a step of applying an external force to the release sheet to move one end portion of the opening strip toward the other surface side of the sheet through the opening formed in the release sheet, thereby projecting the one end portion of the opening strip from the cut line toward the other surface side of the sheet.

Further, a method for manufacturing a packaging sheet material according to the present invention is a method for manufacturing a packaging sheet material in which an opening strip is attached to one surface of a sheet material at a predetermined interval while the sheet material is conveyed in a longitudinal direction, the method including:

forming a cut line in the sheet material blank by the cutting mechanism, and forming a free sheet which is opened when bent and forms an opening by forming the cut line;

a step of arranging the opening strip on one surface of the sheet material by a conveying/joining mechanism located on a downstream side in a sheet material conveying direction from the cutting mechanism so that a portion located on an inner side than one end of the opening strip is superimposed on the free sheet, and joining the opening strip to the one surface of the sheet material within a predetermined range from the free sheet to the other end of the opening strip; and

and a step of applying an external force to the release sheet by an external force applying mechanism located downstream of the conveying/joining mechanism in the conveying direction of the sheet material, thereby moving one end portion of the opening strip toward the other surface side of the sheet material through the opening formed in the release sheet, and projecting the one end portion of the opening strip from the cut line toward the other surface side of the sheet material.

Further, a packaging bag for food of the present invention includes: a bag main body in which a pair of sheets having a shape wider at one end side than at the other end side are superposed, three sides of the bag main body are sealed by a top joining part at one end side and side joining parts at both side edges, and the other end side is an opening part; and a head portion composed of a projecting piece of each sheet projecting from the top joint portion,

one sheet has a free piece formed by forming a cut line at the head, that is, a free piece that opens when bent to form an opening; and an opening strip is provided on the inner surface of one sheet from the free sheet to the other end side of the sheet,

one end of the unsealing strip protrudes from the cut line toward the outer surface of one sheet, and serves as a grip piece for unsealing.

In another method for producing a packaging sheet according to the present invention, the packaging sheet has an opening strip extending in a predetermined direction on one surface of the sheet,

forming a cut line on the sheet;

a step of arranging the opening strip on one surface of the sheet so that a portion of the opening strip on the inner side of one end of the opening strip overlaps the cut line, and bonding the opening strip to the one surface of the sheet within a predetermined range from the cut line to the other end side of the opening strip; and

and a step of applying an external force to the cut line to move one end portion of the opening strip toward the other surface side of the sheet through the opening formed by the cut line, thereby projecting the one end portion of the opening strip from the cut line toward the other surface side of the sheet.

In addition, another method for producing a packaging sheet according to the present invention is a method for producing a packaging sheet having an opening strip extending in a predetermined direction on one surface of the sheet,

forming an opening in the sheet;

a step of arranging the opening strip on one surface of the sheet so that a portion of the opening strip inside the one end portion of the opening strip overlaps the opening, and bonding the opening strip to the one surface of the sheet within a predetermined range from the opening to the other end side of the opening strip; and

and a step of moving one end portion of the opening strip toward the other surface side of the sheet through the opening by applying an external force to the opening, thereby projecting the one end portion of the opening strip from the opening toward the other surface side of the sheet.

Another food packaging bag according to the present invention includes: a bag main body in which a pair of sheets having a shape wider at one end side than at the other end side are superposed, three sides of the bag main body are sealed by a top joining part at one end side and side joining parts at both side edges, and the other end side is an opening part; and a head portion composed of a projecting piece of each sheet projecting from the top joint portion,

one of the sheets has an opening at the head and an opening strip on the inner surface of the one sheet from the opening to the other end side of the sheet,

one end of the unsealing strip protrudes from the opening toward the outer surface side of one sheet and serves as a pinching piece for unsealing.

Effects of the invention

As described above, according to the method for producing a packaging sheet, the method for producing a packaging sheet blank, and the food packaging bag of the present invention, excellent mass productivity can be achieved with a simple structure and a simple method.

Drawings

Fig. 1 is an exploded perspective view of a food packaging bag according to an 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. Fig. 4(b) is an enlarged view of the unsealing start point portion of fig. 4 (a).

Fig. 5(a) is a perspective view of the food package packaged in the food packaging bag, as viewed from the back side thereof. Fig. 5(b) is a perspective view of the food package when it is opened.

Fig. 6 is an explanatory view of a manufacturing process of the food packaging bag, and is an explanatory view of a process of forming a cut line in the second sheet material.

Fig. 7 is an explanatory view of a process of manufacturing the food packaging bag, and is an explanatory view of a process of arranging and joining an opening strip to a second sheet material.

Fig. 8(a) and 8(b) are explanatory diagrams of the structure of an apparatus for carrying out the step of fig. 7.

Fig. 9 is an explanatory view of a manufacturing process of the food packaging bag, and is an explanatory view of a process of projecting one end portion of the opening strip from the cut line toward the opposite surface side of the second sheet material.

Fig. 10 is an explanatory view as viewed from the opposite side to fig. 9.

Fig. 11(a) to (c) are explanatory views of the structure of an apparatus for carrying out the step of fig. 9.

Fig. 12(a) to (c) are explanatory views of another apparatus configuration for carrying out the step of fig. 9.

Fig. 13 is an explanatory view of the steps of manufacturing the food packaging bag, and is an explanatory view of the steps from the first and second sheet materials to the final completion of the food packaging bag.

Fig. 14(a) to (d) are enlarged views of main portions of a food packaging bag according to another embodiment.

Fig. 15(a) to (d) are enlarged views of main portions 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 the food package packaged in the food packaging bag as viewed from the back side thereof, and fig. 17(b) is a perspective view of the food package when opened.

Detailed Description

Hereinafter, a food packaging bag used for packaging a sandwich will be described as one embodiment of the food packaging bag of the present invention with reference to fig. 1 to 13.

As shown in fig. 1 to 3, the food packaging bag 1 of the present embodiment includes a bag main body 10 and a head 15. The bag body 10 is configured such that a pair of sheets (a first sheet 2 and a second sheet 3) having a shape with a width wider at the other end side than at one end side are stacked, three sides are sealed by a top joining portion 11 at one end side and

side joining portions

12 and 12 at both side edges, and the other end side becomes an opening portion 13. The head portion 15 is configured such that the projecting pieces of the

respective sheets

2 and 3 projecting from the top joining portion 11 are joined to each other at appropriate positions to be integrated. Further, the first sheet is also referred to as a front sheet, and the second sheet is also referred to as a back sheet.

The first sheet 2 is made of a plastic sheet having heat-weldability such as polyethylene or polypropylene. The first sheet 2 is configured to have a body portion 20 and a tip portion 21 (the projecting piece). The main body portion 20 has a shape gradually widening from one end side toward the other end side. The distal end portion 21 has a narrow shape extending from one end of the body portion 20.

The second sheet 3 is also made of a plastic sheet having heat-weldability such as polyethylene or polypropylene. The second sheet 3 is configured to have a body portion 30 and a tip portion 31 (the projecting piece). The main body 30 has a shape gradually widening from one end side toward the other end side. The distal end portion 31 has a narrow shape extending from one end of the body portion 30.

In the present embodiment, the

main bodies

20 and 30 have a trapezoidal shape, and the distal ends 21 and 31 have a rectangular shape. Therefore, one end of the main body portion 20, 30 (and the other end of the

tip portion

21, 31 corresponding thereto) is a straight line orthogonal to a direction from one end side to the other end side of the sheet 2, 3 (hereinafter referred to as "longitudinal direction"). In other words, one end of the

main body portions

20 and 30 is linear and parallel to a direction orthogonal to the longitudinal direction (hereinafter referred to as "width direction"). The side edges of the

main bodies

20 and 30 are linear and inclined with respect to the longitudinal direction. Both side edges of the

distal end portions

21, 31 are linear parallel to the longitudinal direction. However, the other end sides of both side edges of the

main bodies

20 and 30 are missing due to the cut portions 14. This narrows the width of the other end of the

main body

20, 30 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

main bodies

20, 30. The side joint portion 12 is formed by heat-sealing side edges (oblique edges) of the

body portions

20 and 30 and side edges (longitudinal edges) of the

distal end portions

21 and 31. In the present embodiment, the top joining portion 11 is formed by welding using a heat seal bar, and is a band-shaped seal portion having a predetermined width in the longitudinal direction. The side joint portion 12 is a wire seal portion formed by fusing. Specifically, the top joint 11 has a width of several millimeters or more. The width of the side joint portion 12 is 1mm or less.

The interior of the bag body 10 thus configured is a food storage portion. An inner sheet 4 is stuck to the inner surface of the first sheet 2 in the bag body 10. The inner sheet 4 is configured such that, for example, the other end is joined at two places by a spot seal or the like (joint portion 22), and one end side is a free end. Thus, even if the food moves in the housing portion, the inner sheet 4 comes into close contact with the surface of the food and follows the movement thereof. Therefore, the first sheet 2 is not contaminated and its appearance is not deteriorated.

As shown in fig. 4, a cut line 32 is formed on the second sheet 3 in the head 15. Further, the second sheet 3 in the head 15 is formed with a free piece 33 by forming a cut-in line 32. The cut-in line 32 is a shape in which both

end points

32a, 32a are close to the top joining portion 11. The free piece 33 is configured to open and form an opening when the fixed end side is bent, with the cut line 32 as a contour line, with a fixed end between the two ends 32a, and with one end side as a free end. In the present embodiment, the incision line 32 is formed in an inverted U shape. Thus, the release sheet 33 has one end edge 33a in the width direction and a pair of left and right side edges 33b, 33b in the longitudinal direction, and is formed as an upward tongue piece.

An opening strip 5 is provided on the inner surface of the second sheet 3 from the free sheet 33 to the other end of the second sheet 3. The opening strip 5 is provided at the widthwise center portion of the second sheet 3, for example, in the longitudinal direction. The opening strip 5 is joined to the inner surface of the second sheet 3 by heat sealing, adhesion, or the like (joint portion 34). For example, after the coating agent is applied to the inner surface (the surface opposite to the second sheet 3), the opening strip 5 is bonded to the inner surface of the second sheet 3 by thermal bonding or self-bonding. The opening strip 5 is, for example, a tear tape or a string. In the present embodiment, the opening strip 5 is a strip-shaped tearable tape having a width of 5mm or more or 10mm or more. The peelable adhesive tape is obtained by cutting a heat-fusible plastic sheet such as biaxially stretched polyester, polyethylene terephthalate (PET), Polyethylene (PE), polypropylene (PP), or biaxially stretched polypropylene (OPP) into thin strips.

The one end portion 5a of the opening strip 5 is not joined to the second sheet 3. The opening strip 5 has one end 5a protruding from the cut line 32 toward the outer surface of the second sheet 3 and serving as a grip piece for opening. Thus, when the one end portion 5a of the opening strip 5 is pinched and pulled downward, the opening strip 5 is pulled, and the second sheet 3 is cut by a predetermined width with the free piece 33 as an opening starting point, thereby forming a cut-open portion in the second sheet 3. If the projecting amount of the one end portion 5a of the opening strip 5 is short, the user is difficult to pinch the opening strip. Conversely, if it is long, it is likely to break, which may hinder the transportability of the manufacturing apparatus. Therefore, the projecting amount of the one end portion 5a of the opening strip 5 is set to be in the range of 5mm or more, or 10mm or more, or 15mm or more, and 25mm or less, or 20mm or less.

As shown in fig. 4(b), the opening strip 5 is also joined to the release sheet 33 and integrated with the release sheet 33. However, the opening strip 5 is not joined to the one end edge 33a of the release sheet 33. Therefore, a non-joined portion having a width G1 exists between the one end edge 34a of the joined portion 34 and the one end edge 33a of the free sheet 33. If the non-joined portion is not provided or the width G1 is small, the joining may be over the cut line 32 due to the influence of the accuracy of the manufacturing apparatus of the food packaging bag 1 or the like (meandering of the sheet material or the like). In this case, the one end portion 5a of the opening strip 5 is locked, and the one end portion 5a cannot protrude from the cut line 32 toward the outer surface side of the second sheet 3. Conversely, if the width G1 is large, the free piece 33 can be pinched, but there is a possibility that a false opening operation may occur in which the pinching is performed without intention of opening the package. In this case, it is needless to say that only the second sheet 3 is pulled without using the opening strip 5, and the opening cannot be properly performed. Therefore, the width G1 of the non-joined portion is set to be in a range of 1mm or more or 1.5mm or more, and 5mm or less or 3mm or less or 2mm or less with respect to the amplitude of the manufacturing error.

The width of the opening strip 5 is smaller than the width of the fixed end of the free sheet 33 (i.e., the distance between the two

ends

32a, 32a of the cut line 32). Therefore, a gap portion having a width G2 exists between each side edge 5b of the opening strip 5 and each side edge 33b of the release sheet 33 or each end point 32a of the cut line 32. If the gap is not provided or the width G2 is small, the one end portion 5a of the opening strip 5 may be caught by the cut line 32, and the one end portion 5a may not be projected from the cut line 32 toward the outer surface side of the second sheet 3. Further, the opening strip 5 is caught by the cutting line 32 due to the influence of the accuracy of the manufacturing apparatus of the food packaging bag 1 and the like (such as positional deviation of sticking), and wrinkles may be generated, which may cause product defects. Therefore, the width G2 of the gap portion is set to be 1mm or more or 1.5mm or more with respect to the amplitude as a manufacturing error.

When packaging food, the opening 13 is opened, the food is inserted into the bag body 10, and then an extra sheet piece (a sheet piece exposed from the bottom surface of the food) in the opening 13 is appropriately folded to close the opening 13, and a label or tape is attached to seal the opening 13. This completes the food package shown in fig. 5 (a). In this food package, the one end portion 5a of the opening strip 5 projects from the cut line 32 toward the outer surface side of the second sheet 3 in the head portion 15 with the free sheet 33 as a fixed end and with the one end side as a free end. On the other hand, the other part of the opening strip 5 extends from the free sheet 33 along the inner surface of the second sheet 3.

When the food is eaten, as shown in fig. 5(b), the one end 5a of the protruding opening strip 5 is pinched and pulled downward. Then, the opening strip 5 is pulled to form a cut-open portion in the second sheet 3, and the food can be taken out from the cut-open portion. In the food package, the one end portion 5a of the opening strip 5 is slightly lifted from the outer surface of the head portion 15 and is easily pinched. Alternatively, the head portion 15 is bent, and the one end portion 5a of the opening strip 5 is sufficiently separated from the head portion 15, so that the opening strip can be more easily pinched. Therefore, the unsealing operation can be smoothly performed.

The food packaging bag of the present embodiment is configured as described above, and a method for manufacturing the food packaging bag of the present embodiment will be described below.

The manufacturing process is roughly divided into the following steps: a step of manufacturing a second sheet material 3X having an unsealing mechanism serving as a pinching piece for unsealing by projecting one end portion 5a of the unsealing strip 5 to the outer surface side of the second sheet 3 as shown in fig. 6 to 12; as shown in fig. 13, a step of manufacturing the food packaging bag 1 from the first sheet material 2X and the second sheet material 3X.

Further, such a food package bag 1 having a trapezoidal shape is manufactured so that the directions thereof are alternately reversed in a lateral direction with respect to the conveying direction of the

sheet material

2X, 3X, depending on the shape thereof. That is, the food packaging bag 1 having the opening 13 formed on one side in the width direction intersecting the conveying direction of the

sheet materials

2X and 3X and the head 15 formed on the other side in the width direction and the food packaging bag 1 having the opening 13 formed on the other side in the width direction and the head 15 formed on one side in the width direction are alternately manufactured. Therefore, in the following description and the drawings, for convenience of description, the former food packaging bag 1 is denoted by the term "one" and denoted by "a" after the reference numeral, and the latter food packaging bag 1 is denoted by the term "the other" and denoted by "B" after the reference numeral.

The step of manufacturing the second sheet material 3X is one embodiment of the method for manufacturing a packaging sheet material and the method for manufacturing a packaging sheet material of the present invention. The process comprises the following steps: i) a step of forming a cut line 32 in the second sheet material 3X, more specifically, forming the cut line 32 in the second sheet material 3X and forming a free piece 33 by forming the cut line 32 (first step), as shown in fig. 6; ii) a step of, as shown in fig. 7 and 8, disposing the opening strip 5 on the inner surface of the second sheet material 3X so that a portion inside the one end portion 5a of the opening strip 5 overlaps the free sheet 33, and joining the opening strip 5 to the inner surface of the second sheet material 3X within a predetermined range from the free sheet 33 to the other end side of the opening strip 5 (second step); and iii) a step of, as shown in fig. 9 to 12, applying an external force to the free sheet 33, more specifically, applying an external force to a portion of the opening strip 5 in the free sheet 33, moving the one end portion 5a of the opening strip 5 toward the opposite surface (outer surface) side of the second sheet material 3X through the opening formed in the free sheet 33, and projecting the one end portion 5a of the opening strip 5 from the cut line 32 toward the opposite surface side of the second sheet material 3X (a third step).

In the first step, the second sheet material 3X is intermittently conveyed. Then, the cutting mechanism (not shown) for the one cutting line 32A and the cutting mechanism (not shown) for the other cutting line 32B arranged on the conveying path are operated in synchronization with the intermittent conveyance of the second sheet material 3X, whereby the one cutting line 32A and the other cutting line 32B are formed, respectively, as shown in fig. 6.

As one example, the lancing mechanism has a receiving roll and a tool. The cutting mechanism reciprocates the tool on the receiving roller, and causes the notch blade provided on the surface of the tool to abut against the receiving roller, thereby forming the cut line 32 in the second sheet material 3X. However, the cutting mechanism is not limited to this configuration. The cutting mechanism may be a mechanism having another structure as long as the cutting line 32 can be formed in the second sheet material 3X.

In the second step, the second sheet material 3X is intermittently conveyed. Then, as shown in fig. 7 and 8, by operating the cutting/conveying/joining

mechanisms

100 and 101 for the opening strip 5A and the cutting/conveying/joining

mechanisms

100 and 101 for the other opening strip 5B arranged on the conveying path in synchronization with the intermittent conveyance of the second sheet material 3X, the one opening strip 5A and the other opening strip 5B are separated from the opening strip sheet material 5X, respectively, conveyed, and arranged and joined (joining

portions

34A and 34B) to the inner surface of the second sheet material 3X.

As an example, the cutting mechanism 100 has a pair of cutting edges. The cutting mechanism 100 cuts the sheet material 5X of the opening strip continuously fed from the roll body in the conveying direction of the

sheet materials

2X and 3X by 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 another structure as long as the opening strip 5 having a predetermined width can be formed.

As an example, the carrying/engaging mechanism 101 has a holding lever 102 and an engaging lever 103. The holding lever 102 is a member that holds the opening strip 5 by sucking it in the longitudinal direction and conveys the opening strip 5 from the cut-off position to the arrangement position at which the second sheet material 3X is arranged. The connecting rod 103 is a member disposed on the opposite surface side of the second sheet material 3X at the position where the opening strip 5 is disposed on the second sheet material 3X. The bonding bar 103 is, for example, a heat-seal bar. The conveying and joining mechanism 101 is configured to hold the unsealing strip 5 formed by cutting by the holding lever 102, convey the unsealing strip 5 by the movement (lifting and lowering in the example of fig. 8) of the holding lever 102, dispose the unsealing strip 5 on the inner surface of the second sheet material 3X, and then heat-seal the second sheet material 3X and the unsealing strip 5 disposed on the inner surface thereof by the holding lever 102 and the joining lever 103, thereby forming the joining portion 34.

Here, one end side of the engagement lever 103 is shorter than the holding lever 102. Therefore, although the opening strip 5 is held by the holding lever 102, the portion of the opening strip 5 which is not sandwiched between the holding lever 102 and the joining lever 103 is not joined to the second sheet material 3X, and becomes the one end portion 5a and the non-joined portion adjacent to the one end portion 5 a.

However, the carrying/joining mechanism is not limited to these configurations. The conveying/joining mechanism may have another structure as long as the opening strip 5 can be joined to the inner surface of the second sheet material 3X with the one end portion 5a and the non-joined portion left, that is, the opening strip 5 can be joined to the inner surface of the second sheet material 3X within a predetermined range from the free sheet 33 to the other end side of the opening strip 5.

In the third step, the second sheet material 3X is intermittently conveyed. Then, as shown in fig. 9 to 12, the external

force applying mechanisms

104 and 105 for the one opening strip 5A and the external

force applying mechanisms

104 and 105 for the other opening strip 5B arranged on the conveying path are operated in synchronization with the conveyance between the second sheet material 3X, so that the one end portion 5A of the one opening strip 5A and the one end portion 5A of the other opening strip 5B are pushed out to the opposite surface side of the second sheet material 3X, respectively.

As an example, the external force applying mechanism has an air nozzle 104 (fig. 11). The external force applying mechanism blows air to the free sheet 33 and the portion of the opening strip 5 of the free sheet 33, so that the free sheet 33 is bent to form an opening, and the one end portion 5a of the opening strip 5 is moved to the opposite surface side of the second sheet material 3X through the opening. Alternatively, as another example, the external force applying mechanism includes a rod 105 (fig. 12) that performs an elevating operation. The external force applying mechanism causes the free piece 33 to be bent to form an opening by bringing the distal end of the rod 105 into contact with the free piece 33 and the portion of the unsealing strip 5 of the free piece 33 and further pushing the rod 105, and moves the one end portion 5a of the unsealing strip 5 to the opposite surface side of the second sheet material 3X through the opening.

However, the external force applying mechanism is not limited to these configurations. The external force applying mechanism may be a mechanism having another structure as long as the one end portion 5a of the opening strip 5 can be moved to the opposite surface side of the second sheet material 3X. For example, a suction mechanism or an adsorption mechanism may be disposed on the opposite surface side of the second sheet material 3X, and the release sheet 33 may be sucked or adsorbed from the opposite surface side, so that the one end portion 5a of the opening strip 5 may be moved to the opposite surface side of the second sheet material 3X.

The second sheet material blank 3X is manufactured as described above. Then, the second sheet material 3X is wound into a roll shape and then attached to a bag-making apparatus. Alternatively, the second sheet material 3X is manufactured by the bag-making apparatus and continuously conveyed, and then the process proceeds to a step of manufacturing the food packaging bag 1 from the first sheet material 2X and the second sheet material 3X.

The process for producing the food packaging bag 1 is a conventionally used method, as described in, for example, japanese patent application laid-open No. 2005-219319. Therefore, the description will not be made herein. As shown in fig. 13, this process includes: iv) forming the top joined portion 11 while overlapping the first sheet material 2X and the second sheet material 3X so that the inner surfaces thereof face each other and intermittently conveying the same; v) a step of independently separating the food packaging bag 1 while forming the side joining part 12; and vi) forming a cut portion 14. Through these steps, the food packaging bag 1 is completed. Although not shown, the step of joining the inner sheet 4 to the inner surface of the first sheet material 2X is performed before the first sheet material 2X and the second sheet material 3X are superposed.

As described above, according to the method of manufacturing the second sheet material 3X having the unsealing mechanism in which the one end portion 5a of the unsealing strip 5 protrudes toward the outer surface side of the second sheet 3 and serves as the pinching piece for unsealing, it is possible to realize excellent mass productivity with a simple structure and a simple method.

The direction in which the one end portion 5a of the opening strip 5 extends coincides with the direction in which the free piece 33 extends (both of them are raised upward). Therefore, the one end portion 5a of the opening strip 5 can be reliably moved to the opposite surface side of the second sheet material 3X with a small force.

The present invention is not limited to the above embodiments. The present invention can be variously modified within a range not departing from the gist of the present invention.

The shapes and structures of the incision line and the free piece are not limited to those of the above embodiments. For example, the shape and structure of the incision line and the free piece may be the same as those shown in fig. 14 and 15.

As shown in fig. 14(a), a display portion 50 which can be recognized from the peripheral region is added to the one end portion 5a of the opening strip 5. Normally, the opening strip 5 is transparent. Therefore, the one end portion 5a is not conspicuous as it is. It is considered that the consumer of the product cannot easily recognize where the tab is used for opening. Therefore, any consumer of the product can easily recognize the opening tab by adding the printed display portion 50 or the like to the one end portion 5a of the opening strip 5.

As the display unit, in addition to the display unit 50 configured to display information of the opening tab, a display unit 51 configured by a single color, a pattern, or the like that can be recognized from the peripheral area as shown in fig. 14(b) may be used instead of the display unit 50.

As shown in fig. 14 c, a pi-shaped incision line 32 is formed, that is, an incision line 32 is formed which is composed of a line (lateral line) 32b extending in the width direction intersecting the longitudinal direction and left and right lines (vertical lines) 32c, 32c extending in the longitudinal direction from positions inward of both ends of the line 32 b. According to this configuration, after the one end portion 5a of the holding opening strip 5 is opened in the longitudinal direction (longitudinal direction), the head portion 15 is formed with the

cut lines

32d, 32d facing outward in the width direction. Therefore, the remaining second sheet 3 after the opening can be opened to the left and right to increase the cut-open portion, and the food can be easily taken out.

As shown in fig. 14(d), an X-shaped incision line 32 is formed in which two

oblique incision lines

32e and 32e intersect. According to this configuration, after the opening, the head portion 15 is formed with the

cut lines

32f, 32f directed outward in the width direction. Therefore, the second sheet 3 remaining after the opening can be opened to the left and right to be completely opened.

As shown in fig. 15 a, the configuration is such that an H-shaped incision line 32, that is, an incision line 32 including a line (lateral line) 32g extending in the width direction intersecting the longitudinal direction and right and left lines (vertical lines) 32H, 32H extending in both the longitudinal directions from both ends of the line 32g is formed. According to this structure, in addition to the upward free piece 33, a downward free piece 35 can be formed so as to face the free piece 33.

As shown in fig. 15(b), the downward cut line 32, that is, the cut line 32 in which the direction in which the one end portion 5a of the opening strip 5 extends is opposite to the direction in which the free piece 35 extends is formed.

The incision line may be a straight line or a slightly curved line such as a line in the width direction (lateral line) intersecting the longitudinal direction or a line inclined with respect to the width direction.

As a structure for moving the one end portion 5a of the opening strip 5 to the opposite side of the second sheet 3, the combination of the cut-in line 32 and the release sheet 33 may be omitted, or the opening 36 may be provided as shown in fig. 15 (c). Even in the opening 36, the device and method for moving the 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.

As shown in fig. 15(d), the second sheet 3 and the opening strip 5 may be formed so that the centers thereof coincide with each other at the joint portion 34. The joint portion may be formed over the entire width of the opening strip 5. The joint portions may be formed only at both widthwise edge portions of the opening strip 5. Further, the joint portion need not be formed up to the other end of the opening strip 5. In short, the opening strip 5 may not be peeled from the second sheet 3.

The joint portion is not limited to a structure formed continuously in the longitudinal direction. For example, the joint portion may be a point seal formed at an appropriate position including a position in the free piece 33.

The cut line is not limited to a full tangent line. The incision line may be broken when an external force is applied by the external force applying mechanism. For example, the cut-in line may be a half-cut line (half-cut) or a perforated line.

The unsealing strip is not limited to being formed of one member. For example, the unsealing strip may be formed by integrally joining a main body portion and one end portion of a separate body.

The unsealing mechanism may be provided not in the second sheet 3 but in the first sheet 2.

In addition, the terms indicating the shape, the portion, or the state such as "trapezoidal", "rectangular", "straight", "central", "end", "side", "matching", and "parallel" in the present invention include the concept of "substantially" similar or analogous to the term, in addition to the term itself.

The food to be packaged is not limited to sandwiches. The food may be in a shape that can be stored in a food packaging bag. For example, the food may be a cooked rice processed food such as bread, cake, or rice ball. Thus, the kind of food is not limited.

The method for producing the packaging sheet of the present invention is not limited to the above embodiment. The present invention can be variously modified within a range not departing from the gist of the present invention.

The packaging sheet is not limited to a specific packaging method. The packaging sheet can be used for all kinds of articles in various packaging methods, such as an outer sheet in a food packaging material in which a rice ball and a laver sheet are packaged in a separated state, a sheet used for a general bag such as a pillow packaging sheet, a flat bag, and a side-folded bag.

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

The packaging sheet is not limited to a plurality of continuous long sheets. For example, the packaging sheet may be a single sheet.

The packaging sheet is not limited to being formed of a single plastic sheet. For example, the packaging sheet may be a sheet made of other material such as paper or paper sheet. The packaging sheet may be a sheet formed by using a plurality of sheets, for example, in such a manner that the ends of two sheets are joined to each other to form one sheet, and the ends of three sheets are successively joined to each other to form one sheet. In this case, the material of each sheet may be different. For example, a portion of the sheet material may be paper or a paper sheet material instead of a plastic sheet material.

Description of the reference numerals:

1. 1A, 1B: packaging bag for food

10: bag main body

11. 11A, 11B: top joint

12. 12A, 12B: side joint

13: opening part

14. 14A: cut-out part

15: head part

2: first sheet (surface sheet)

2X: first sheet blank

20: main body part

21: tip end portion

22: joint part

3: second sheet (Back sheet)

3X: second sheet blank

30: main body part

31: tip end portion

32. 32A, 32B: cutting-in line

32 a: endpoint

32 b-32 h: cutting-in line

33. 33A, 33B: free tablet

33 a: one end edge

33 b: skirt edge

34. 34A, 34B: joint part

34 a: one end edge

35: free tablet

36: opening of the container

4: inner sheet

5. 5A, 5B: unsealing strip

5X: unsealing strip sheet material

5 a: one end (holding sheet)

5 b: skirt edge

50: display unit

51: display unit

100: cutting mechanism

101: conveying/joining mechanism

102: retaining rod

103: joint lever

104: air nozzle (external force applying mechanism)

105: stick (external force applying mechanism)

L1: center lines in the width direction of the opening strip 5 and the release sheet 33

L2: center line of the joint 34 in the width direction

G1: the distance between one end edge 34a of the joining portion 34 and one end edge 33a of the free sheet 33 (the width of the non-joining portion)

G2: the distance between the side edge 5b of the opening strip 5 and the end 32a of the cutting line 32 (the width of the gap part)

S1: offset of center line L1 from center line L2

Claims

1. A method of manufacturing a packaging sheet having an opening strip extending in a predetermined direction on one surface of the sheet,

2. A method for manufacturing a sheet material for packaging, wherein an opening strip is stuck to one surface of a sheet material at a predetermined interval while the sheet material is conveyed in a longitudinal direction,

the method for manufacturing the sheet blank for packaging comprises the following steps:

3. The method of manufacturing a packaging sheet material blank as claimed in claim 2,

the external force applying mechanism may be any of a mechanism for blowing air from an air nozzle to the release sheet, a mechanism for bringing the tip end of the rod into contact with the release sheet and pushing the rod in, and a mechanism for adsorbing or sucking the release sheet.

4. The method of manufacturing a packaging sheet material blank as claimed in claim 2,

the joining step includes a step of joining the opening strip and the free sheet so that a non-joined portion having a predetermined width is formed between one end edge of the joined portion and the cut line.

5. A method of manufacturing a sheet blank for packaging as claimed in any of claims 2 to 4,

the joining step includes a step of joining a portion of the opening strip, which is offset from the center in the width direction, along the longitudinal direction of the opening strip.

6. A packaging bag for food, comprising: a bag main body in which a pair of sheets having a shape wider at one end side than at the other end side are superposed, three sides of the bag main body are sealed by a top joining part at one end side and side joining parts at both side edges, and the other end side is an opening part; and a head portion composed of a projecting piece of each sheet projecting from the top joint portion,

7. The packaging bag for food according to claim 6,

the cut-in line has a shape with both end points close to the top joint,

thus, the free piece has a shape in which a fixed end is located between both ends of the cut line and a free end is located on one end side separated from the apex-joining section.

8. The packaging bag for food according to claim 7,

the opening strip is joined to the inner surface of one sheet within a predetermined range from the free sheet to the other end side of the opening strip,

a non-joint portion having a predetermined width is present between one end edge of the joint portion and the cut line.

9. The packaging bag for food according to claim 7 or 8,

the width of the unsealing strip is smaller than the interval between the two end points of the cut-in line,

thus, a gap portion having a predetermined width is provided between each side edge of the opening strip and each end point of the cut line.

10. The packaging bag for food according to claim 6,

one end of the opening strip has a display portion which is visible from a peripheral region of the one end.

11. A method of manufacturing a packaging sheet having an opening strip extending in a predetermined direction on one surface of the sheet,

forming a cut line on the sheet;

12. A method of manufacturing a packaging sheet having an opening strip extending in a predetermined direction on one surface of the sheet,

forming an opening in the sheet;

13. A packaging bag for food, comprising: a bag main body in which a pair of sheets having a shape wider at one end side than at the other end side are superposed, three sides of the bag main body are sealed by a top joining part at one end side and side joining parts at both side edges, and the other end side is an opening part; and a head portion composed of a projecting piece of each sheet projecting from the top joint portion,