JP7471196B2 - Food packaging bag and method for manufacturing the same - Google Patents

Description

The present invention relates to a food packaging bag for packaging food and a method for manufacturing the 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. Food packaging bags for packaging such foods are generally as shown in Figures 28 and 29(a), and a newer one is known, such as that described in Patent Document 1.

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', for example, an inverted U-shaped cut line 32' is formed, and a tear strip 33' is formed with the cut line 32' as an outline. A tear strip 34' such as a cutting tape is joined to the inner surface of the second sheet 3' from the tear strip 33' to the other end of the second sheet 3'.

When eating food packaged in the food packaging bag 1', the opening strip 33' is picked up and pulled down as shown in FIG. 29(b). This pulls the opening strip 34', causing the second sheet 3' to break along both side edges of the opening strip 34', forming a tear-open section in the second sheet 3'. The food can be removed from this tear-open section.

JP 2017-171326 A

This type of food packaging material is made up of only plastic sheets. However, waste plastic has become a global environmental problem, making it an urgent task to reduce the amount of plastic used.

Therefore, the present invention was made in consideration of these circumstances, and aims to provide a food packaging bag and a method for manufacturing the food packaging bag that can reduce the amount of plastic used while also providing additional value beyond this.

The food packaging bag according to the present invention is
A food packaging bag is provided which is formed by overlapping a first sheet having a shape in which one end side is wider than one end side in a first direction with a second sheet having the same shape as the first sheet and an opening means along the first direction, the bag body being sealed on three sides by a top joint at one end and side joints at both sides, with the other end side being an opening, and a header portion formed by protruding pieces of each sheet protruding from the top joint,
The first sheet is divided into three regions, a central region and two side regions, by two boundary lines spaced apart in a second direction perpendicular to the first direction;
A paper sheet is used for the side of the first sheet and the second sheet,
The distance between the two boundary lines is smaller than the width of the top joint of the food packaging bag.

Here, as one embodiment of the food packaging bag according to the present invention,
The side joint portion may be formed in a strip shape of a predetermined width along the side edge of the bag body and the side edge of the header portion.

In another aspect of the food packaging bag according to the present invention,
The first sheet includes a central sheet and two side sheets made of paper, and includes a joint portion at the overlapping portion between the side edge of the central sheet and the side edge of the side sheet;
The central sheet is formed by removing the overlapping portions of both side edges from the central sheet, and the central sheet is formed by removing the overlapping portions of both side edges from the central sheet.
A configuration may be adopted in which the side sheets are the sides of the first sheet.

Also, in this case,
The structure may include an inner sheet having a width smaller than the distance between the inner edges of the two joints and disposed on the inner surface of the central sheet.

In addition, the method for producing a food packaging bag according to the present invention includes the steps of:
A method for manufacturing a food packaging bag comprising: a first sheet having a shape that is wider at one end side than at the other end side in a first direction; and a second sheet having the same shape as the first sheet and an opening means along the first direction, the bag body being sealed on three sides by a top joint at one end and side joints at both sides, with the other end side being an opening; and a header portion composed of protruding pieces of each sheet protruding from the top joint,
A process for producing a tube in which a portion in a circumferential direction has a predetermined width and the other portion is made of a paper sheet, the portion in the circumferential direction being flattened so as to be located at a center portion of one surface;
forming a band-like joint portion on the tube to be the top joint portion along the width direction of the tube;
forming a joint portion for the tube in a band shape obliquely relative to a side edge of the tube;
cutting the tube in a width direction at a tip position of a portion that will become a header portion;
and cutting the tube obliquely along a widthwise middle position of the joint that will become the side joint.

Here, as one embodiment of the method for producing a food packaging bag according to the present invention,
The process for making the tube is as follows:
A step of conveying a belt-shaped central sheet raw material and first and second sheet raw materials made of paper sheets and wider than the central sheet raw material along a longitudinal direction of the sheet raw material;
A step of overlapping a side edge portion of the central sheet raw material with side edge portions of the first and second sheet raw materials;
and forming a joint portion in the overlapping portion along the longitudinal direction of the raw sheet.

As described above, according to the present invention, paper sheets are used over a wide range of sheets. Therefore, according to the present invention, the amount of plastic used can be significantly reduced.

Furthermore, according to the present invention, a paper sheet is used, which has higher rigidity than a plastic sheet. Therefore, according to the present invention, the rigidity of the food package can be improved. And, according to the food packaging bag of the present invention, four angled pillars made of a paper sheet are formed at the four corners of the food package. Therefore, according to the food packaging bag of the present invention, the rigidity of the food package in the vertical direction can be improved.

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 an outer view of the first sheet of the food packaging bag, and Fig. 4(b) is a cross-sectional view taken along line AA of Fig. 4(a). Fig. 5(a) is an outer view of the second sheet of the food packaging bag, and Fig. 5(b) is a cross-sectional view taken along line BB of Fig. 5(a). 6(a) to (c) are explanatory diagrams showing the process of packaging food using the food packaging bag. 7(a) to (d) are explanatory diagrams continuing from FIG. Fig. 8(a) is a perspective view of a food package packaged in the food packaging bag as seen from the front side, and Fig. 8(b) is a cross-sectional view taken along line CC of Fig. 8(a). FIG. 9 is an explanatory diagram of an initial step of the first manufacturing method of the food packaging bag. FIG. 10 is an explanatory diagram of the process subsequent to that of FIG. FIG. 11 is an explanatory diagram of the process subsequent to that of FIG. FIG. 12 is an explanatory diagram of a process different from those in FIG. 10 and FIG. FIG. 13 is an explanatory diagram of a process subsequent to FIG. 11 or FIG. FIG. 14 is an explanatory diagram of the process subsequent to that of FIG. FIG. 15 is an explanatory diagram of the process following FIG. 14 (final process). FIG. 16 is an explanatory diagram of an initial step of the second manufacturing method of the food packaging bag. FIG. 17 is an explanatory diagram of a process different from that in FIG. FIG. 18 is an explanatory diagram of a process subsequent to that of FIG. 16 or FIG. FIG. 19 is an explanatory diagram of the process subsequent to that of FIG. FIG. 20 is an explanatory diagram of the process subsequent to that of FIG. FIG. 21 is an explanatory diagram of the process subsequent to that of FIG. FIG. 22 is an explanatory diagram of the process following FIG. 21 (final process). Fig. 23(a) is a cross-sectional view of a first sheet of a food packaging bag according to another embodiment, and Fig. 23(b) is a transverse cross-sectional view of a food package packaged using the food packaging bag. FIG. 24 is a front view of a food packaging bag according to still another embodiment. Fig. 25(a) is a perspective view of a food package packaged in the food packaging bag as seen from the front side, and Fig. 25(b) is a cross-sectional view taken along line DD of Fig. 25(a). Fig. 26(a) is a cross-sectional view of a food package packaged in a food packaging bag according to another embodiment, and Fig. 26(b) is a cross-sectional view of a food package packaged in a food packaging bag according to yet another embodiment. FIG. 27 is a front view of a food packaging bag according to yet another embodiment. FIG. 28 is a front view of a conventional food packaging bag. Fig. 29(a) is a perspective view of a food package packaged in the food packaging bag as viewed from the front side, and Fig. 29(b) is a perspective view of the food package being 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 8.

As shown in Figs. 1 to 3, the food packaging bag 1 according to this embodiment includes a bag body 10 and a header portion 15. The bag body 10 is formed by overlapping and joining a pair of sheets (a first sheet 2 and a second sheet 3). The first sheet 2 is also called the front sheet, and the second sheet 3 is also called the back sheet. The pair of sheets have a shape in which one side in a direction perpendicular to each other is longer than the other, and the other end side is wider than the one end side. The bag body 10 is joined and sealed on three sides by a top joint portion 11 at one end and side joint portions 12, 12 at both sides, and the other end side is an opening portion 13. The header portion 15 is formed by joining the protruding pieces of the sheets 2, 3 protruding from the top joint portion 11 to each other at appropriate locations and integrating them. In the following, the one of the above directions (the vertical direction in Figs. 2 and 3) will be referred to as the "longitudinal direction" or "first direction," and the other direction (the horizontal direction in Figs. 2 and 3) will be referred to as the "width direction" or "second direction."

As shown in FIG. 4, the first sheet 2 has a body portion 20 and a tip portion 21 (the protruding piece). The body portion 20 has a shape that gradually becomes wider from one end side to the other end side. The tip portion 21 has a narrow shape that extends from one end of the body portion 20.

The first sheet 2 is divided into three regions, a central portion 22 and two side portions 23, 23, by two parallel boundary lines B, B that run along the longitudinal direction and are spaced apart in the width direction. The central portion 22 is divided into the central portion and the tip portion 21 of the body portion 20. The side portions 23 are divided into the sides of the body portion 20.

The first sheet 2 is made into a single sheet by overlapping three sheets (a central sheet 24 and two side sheets 25, 25) at their side edges (overlapped portion 26) and joining the overlapped portion 26 by heat sealing (jointed portion 27). In the overlapped portion 26, the side edge of the side sheet 25 is disposed on the outer surface side of the side edge of the central sheet 24, and the side edge of the central sheet 24 and the side edge of the side sheet 25 are overlapped so that the outer surface of the side edge of the central sheet 24 faces the inner surface of the side edge of the side sheet 25.

The joint 27 is formed by heat sealing the overlapping portion 26 along the side edge of the central sheet 24 and the side edge of the side sheet 25 over the entire length. In this embodiment, the joint 27 is a strip-shaped seal having a predetermined width, formed by welding using a heat seal bar. The width of the joint 27 is narrower than the width of the overlapping portion 26. As a result, the portion of the side edge of the central sheet 24 beyond the joint 27 and the portion of the side edge of the side sheet 25 beyond the joint 27 are free ends. In this embodiment, the joint 27 has a width of about 2 mm to 20 mm, and the free ends have a width of about 0 mm to 5 mm.

The central sheet 24 has a long rectangular shape (rectangular shape) in the longitudinal direction. The central sheet 24 is a moisture-proof cellophane sheet (film). Alternatively, the central sheet 24 is a plastic sheet (plastic film) having heat-welding properties, such as polyethylene (PE), polypropylene (PP), or polyethylene terephthalate (PET). In this embodiment, the central sheet 24 is a moisture-proof cellophane sheet (film) or a biaxially oriented polypropylene (OPP) sheet (film). Note that the polypropylene sheet (film) is a concept that includes not only a 100% pure polypropylene sheet (film), but also a sheet (film) that contains polypropylene as the main component and other components (for example, other resin components such as polyethylene) (the same applies below).

The side sheet 25 is a sheet (film) made of paper, unbleached kraft paper, Japanese paper, mixed paper, synthetic paper, glassine paper, paper-like or paper-like material, or mainly made of these, and has thermal adhesion properties on the inner side (collectively referred to as "paper sheet" (film)). In this embodiment, the side sheet 25 is a laminated sheet (film) made by laminating a biaxially oriented polypropylene (OPP) sheet (film) to unbleached kraft paper.

The central portion 22 corresponds to the central sheet 24 excluding the left and right overlapping portions 26, 26. The side portions 23 correspond to the side sheets 25. As a result, in the first sheet 2, the central portion 22 is a transparent portion through which the interior can be seen, and the left and right side portions 23, 23 are opaque (or translucent) portions.

Here, the distance WB between the two boundary lines B, B (width of the central portion 22) is smaller than the width W11 of the top joint 11 (the length of the inner edge of the top joint 11, the ends of which intersect with the inner edges of the side joints 12 (see FIG. 2), which corresponds to the width of the storage section of the food package 6 described below or the width of the sandwich 5 (see FIG. 8)). More specifically, the width WB is 35% or more, or 45% or more, and 97% or less, or 90% or less of the width W11.

The distance W27a between the inner edges of the two joints 27, 27 is smaller than the width W11 of the apex joint 11, and the distance W27b between the outer edges of the two joints 27, 27 is larger than the width W11 of the apex joint 11 (W27a<W11<W27b). As a result, a perpendicular line passing through the end point of the inner edge of the apex joint 11 is parallel to the inner and outer edges of the joint 27 and passes between the inner and outer edges of the joint 27.

As shown in FIG. 5, the second sheet 3 has a body portion 30 and a tip portion 31 (the protruding piece). The body portion 30 has a shape that gradually becomes wider from one end side to the other end side. The tip portion 31 has a narrow shape that extends from one end of the body portion 30.

The second sheet 3 is a paper sheet (film) like the side sheet 25 of the first sheet 2. In this embodiment, the second sheet 3 is a laminated sheet (film) in which a biaxially oriented polypropylene (OPP) sheet (film) is laminated to unbleached kraft paper like the side sheet 25.

As shown in Figs. 1 to 3, 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 longitudinal direction. In other words, one end of the body 20, 30 is linear and parallel to the width direction. Both side edges of the body 20, 30 are linear and inclined relative to the longitudinal direction. Both side edges of the tip 21, 31 are also linear and inclined relative to the longitudinal direction. However, both side edges of the tip 21, 31 may be linear and parallel to the longitudinal direction. The other end side of both side edges of the body 20, 30 is missing by the notch 14. As a result, the other end side of the body 20, 30 is narrowed by 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. In this embodiment, the top joint 11 is formed by welding using a heat seal bar, and is a strip-shaped seal having a predetermined width.

The side joint 12 is formed by heat sealing the first and second sheets 2, 3 along the side edges (oblique sides) of the body portions 20, 30 and the side edges (oblique sides or vertical sides) of the tip portions 21, 31. In this embodiment, the side joint 12 is formed by welding using a heat seal bar, and is a strip-shaped seal having a predetermined width. The width of the side joint 12 is smaller than the width of the top joint 11. Specifically, the side joint 12 has a width of about 2 mm to 5 mm.

The interior of the bag body 10 thus constructed serves as a food storage section. An inner sheet 4 is attached to the inner surface of the first sheet 2 (the central sheet 24) in the bag body 10. The width W4 of the inner sheet 4 is smaller than the distance W27a between the inner edges of the two joints 27, 27. As a result, the inner sheet 4 is positioned so that the side edges 4a, 4a are on the inside of the left and right joints 27, 27 without overlapping the left and right joints 27, 27. The inner sheet 4 is joined by heat sealing at the top joint 11, and is a free end within the storage section. 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 (the central sheet 24) does not become dirty and its appearance is not impaired.

A cut line 32 is formed in the second sheet 3 in the header section 15. The cut line 32 forms an opening piece 33 in the second sheet 3 in the header section 15. The opening piece 33 has the cut line 32 as its outline, a fixed end between both end points, and a free end at one end. In this embodiment, the cut line 32 is formed in an inverted U-shape. As a result, the opening piece 33 becomes an upward tongue piece.

The second sheet 3 is provided with an opening strip 34 as an opening means. The opening strip 34 is provided on the inner surface of the second sheet 3 from the opening piece 33 to the other end of the second sheet 3. The opening strip 34 is provided, for example, along the longitudinal direction at the center of the width of the second sheet 3. The opening strip 34 is joined to the inner surface of the second sheet 3 by heat sealing, adhesion, or the like. As an example, the opening strip 34 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 34 is, for example, a cut tape or a thread. In this embodiment, the opening strip 34 is a strip-shaped cut tape having a width of 5 mm or more or 10 mm or more. Cut tape is made by cutting thin strips of heat-weldable plastic sheets such as biaxially oriented polyester, polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and biaxially oriented polypropylene (OPP).

The food packaging bag 1 according to this embodiment has the above configuration, and next we will explain the method of packaging food using this food packaging bag 1.

First, as shown in FIG. 6(a), air at a predetermined pressure is blown into the bag body 10 from the opening 13 with a blower (not shown), or the opening 13 side of the first sheet 2 is sucked and lifted with a suction head (not shown) to open the opening 13. Then, in this state, the sandwich 5 is inserted into the bag body 10.

When the sandwich 5 is placed inside the bag body 10, the opening shape of the opening 13 becomes rectangular, as shown in FIG. 1B. The portions spanning the side joints 12 of the first sheet 2 and the second sheet 3 become a pair of opposing triangular side portions. The middle portion of the first sheet 2 becomes a rectangular front portion. The middle portion of the second sheet 3 becomes a rectangular back portion.

After the sandwich 5 is contained in the bag body 10, first, as shown in FIG. 7(c), the sheet piece (back sheet piece) of the second sheet 3 among the excess sheet pieces (sheet pieces protruding from the bottom surface of the sandwich 5) at the opening 13 is folded so as to cover the bottom surface of the sandwich 5. Next, as shown in FIG. 7(a), either the left or right sheet piece (one side sheet piece) is folded so as to overlap the second sheet 3 previously folded. Next, as shown in FIG. 7(b), either the left or right sheet piece (the other side sheet piece) is folded so as to overlap the second sheet 3 previously folded. Next, as shown in FIG. 7(c), the remaining sheet piece (front sheet piece) of the first sheet 2 is folded so as to overlap the left and right sheet pieces previously folded. This closes the opening 13 of the food packaging bag 1.

However, the order in which the four sheet pieces are folded is not particularly limited; first, the sheet piece at the front is folded, then the sheet piece at the side is folded, and finally, the sheet piece at the back is folded; first, either the sheet piece at the back or the front is folded, then the other sheet piece at the back or the front is folded, and finally, the sheet piece at the side is folded; first, the sheet piece at the side is folded, then the sheet piece at the back or the front is folded, and finally, the other sheet piece at the back or the front is folded, etc.

Once the opening 13 is closed, tape 7 is applied to seal the opening 13. Alternatively, a label may be applied, or the folded and overlapping sheet pieces may be joined at predetermined locations by heat sealing or the like to seal the opening 13.

Through the above steps, the food package 6 is completed as shown in FIG. 8(a). The food package 6 is kept airtight by the top joint 11, the side joints 12, 12, and the closed portion (bottom portion) of the sealed opening 13. This prevents outside air from entering the inside, and the packaged sandwich 5 maintains the intended quality.

As shown in FIG. 8(b), in the state where the food package 6 is formed, the side 6a2, side surface 6b and back surface 6c of the front surface 6a of the food package 6 are made up of opaque (or semi-transparent) left and right side sheets 25, 25 (left and right side portions 23, 23) and the second sheet 3. The main portion 6a1 of the front surface 6a of the food package 6, excluding the side portions 6a2, is made up of a transparent center sheet 24 (center portion 22). Therefore, the sandwich 5 is visible only in the main portion 6a1 (center portion 22) of the front surface 6a of the food package 6, excluding the left and right side portions 6a2, 6a2.

The left and right corners on the back side of the sandwich 5 are covered by the folded portions of the second sheet 3, and the left and right corners on the front side of the sandwich 5 are covered by the folded portions of the left and right side sheets 25, 25 of the first sheet 2. That is, in the food package 6, four angled columns made of paper sheets are formed at the four corners of the sandwich 5, extending along the sides of the corners of the sandwich 5.

When eating the sandwich 5, the opening strip 33 is picked up and pulled down. The opening strip 33 is joined to one end of the opening strip 34. Therefore, when the opening strip 33 is picked up and pulled down, the opening strip 34 is pulled and the second sheet 3 is broken along both side edges of the opening strip 34, forming a breakable open portion in the second sheet 3. The sandwich 5 can be removed from this breakable open portion.

As described above, according to the food packaging bag 1 of this embodiment, paper sheets are used for part of the first sheet 2 and the second sheet 3, and the usage rate of paper sheets is high. Therefore, according to the food packaging bag 1 of this embodiment, the amount of plastic used can be significantly reduced. In recent years, waste plastic has become a global environmental problem, and the food packaging bag 1 of this embodiment provides an effective measure against this environmental problem.

In addition, paper sheets have higher rigidity than plastic sheets. This gives sheet 2 strength, which has the effect of improving the self-supporting ability of food packaging body 6 when it is formed. In addition, the strength of sheets 2 and 3 improves the rigidity of food packaging body 6. Therefore, the food packaging bag 1 according to this embodiment is highly effective in preventing sandwich 5 from losing its shape.

Moreover, according to the food packaging bag 1 of this embodiment, in the state where the food package 6 is formed, four angle-shaped pillars made of paper sheets are formed at the four corners of the food package 6 that face the four corners (in the cross section) of the sandwich 5, and extend along the sides of the four corners of the sandwich 5. This increases the rigidity of the food package 6 in the vertical direction. During the product distribution process, the food packages 6 are stacked not only horizontally but also vertically in a transport tray so as to fill the triangular space. If the conventional food package is made only of plastic sheets, the rigidity in the vertical direction is low, so that a vertical compressive force is applied to the sandwich when the food packages are stacked, and the sandwich may be crushed. However, according to the food packaging bag 1 of this embodiment, the rigidity of the food package 6 in the vertical direction is high, and the sandwich can be suitably prevented from being crushed.

In addition, paper sheets are more susceptible to creases than plastic sheets. As a result, the sheet 2 is bent sharply at each side of the food package 6, and the food package 6 has a sharp appearance. Therefore, the food packaging bag 1 according to this embodiment has the effect of providing an excellent appearance, stability, and self-supporting ability in the form of a food package 6.

Moreover, when packaging sandwiches 5 with the food packaging bag 1 according to this embodiment, the excess sheet pieces at the opening 13 are folded to close the opening 13 (see FIG. 6(c) and FIG. 7(a) to (c)). However, all four excess sheet pieces around the opening 13 contain paper sheets and are prone to creases. With a conventional food packaging bag made only of plastic sheets, the excess sheet pieces tend to return to their original shape even after folding due to the elastic repulsive force of the sheet, which may prevent the closing operation from being performed smoothly. However, with the food packaging bag 1 according to this embodiment, the folded excess sheet pieces are less likely to return to their original shape, allowing the closing operation of the opening 13 to be performed smoothly.

Furthermore, with the food packaging bag 1 according to this embodiment, when the sandwich 5 is in the food packaging body 6, the sides and back of the sandwich 5 in an upright position are hidden by an opaque paper sheet, and only the front of the sandwich 5 is visible through the transparent sheet. In other words, only the front part of the sandwich 5, which looks the most delicious, is visible and emphasized. Therefore, with the food packaging bag 1 according to this embodiment, when the sandwich 5 is in the food packaging body 6, it is possible to stimulate the consumer's desire to purchase.

Furthermore, according to the food packaging bag 1 of this embodiment, the side joint portion 12 is formed in a band shape with a predetermined width along the side edge of the bag body 10 and the side edge of the header portion 15. As a result, when the food packaging body 6 is formed, the side joint portion 12 is in a state where it is folded backward as shown in FIG. 8. Then, the header portion 15 is in an upright state because pillar portions are formed on both sides. Moreover, the header portion 15 is in a flat state where it extends straight from the front portion of the bag body 10. Therefore, according to the food packaging bag 1 of this embodiment, when the food packaging body 6 is formed, it is possible to improve the appearance, and it is possible to easily see the display on the header portion 15 when it is displayed in a store such as a convenience store.

Next, we will explain the manufacturing method of the food packaging bag 1 according to this embodiment. There are two main manufacturing methods.

<First manufacturing method>
The first manufacturing method is shown in Figures 9 to 15. The first manufacturing method includes:
i) preparing a tube having a transparent sheet in one circumferential portion and a paper sheet in the other circumferential portion, the transparent sheet being flattened so as to be located in the center of one side, as shown in Figs. 9 to 13;
ii) forming a band-like joint portion that will become the top joint portion 11 on the tube in the width direction of the tube, as shown in FIG. 13;
iii) forming a joint portion for forming the side joint portion 12 on the tube in a band shape obliquely relative to the side edge of the tube, as shown in FIG. 14;
iv) cutting the tube in the width direction at the tip position of the portion that will become the header portion 15, as shown in FIG.
and v) cutting the tube obliquely along a widthwise middle position of the joint that will become the side joint 12, as shown in FIG.
The first manufacturing method further comprises:
vi) forming the notch 14 as shown in FIG.

Step i) comprises
ii) as shown in FIG. 9, a step of attaching an opening strip 34 to the inner surface of the first and second sheet rolls 2, 3X made of paper sheets along the longitudinal direction of the sheet rolls;
i-ii) forming cut lines 32 at a fixed pitch along the longitudinal direction of the sheet material on the opening strip 34 as shown in FIG.
i-iii) conveying a belt-shaped central sheet roll 24X made of a transparent sheet and the first and second sheet rolls 2 and 3X along the longitudinal direction of the sheet rolls, as shown in FIG. 10 and FIG. 11 or FIG. 12;
i-iv) overlapping the side edge of the central sheet roll 24X with the side edge of the first and second sheet rolls 2 and 3X as shown in FIG. 11 or 12;
iv) As shown in FIG. 13, a step of forming a joint 27 in the overlapping portion along the longitudinal direction of the raw sheet.
Steps i-iii) further comprise:
i-iii-i) As shown in FIG. 11 or 12, the method includes a step of conveying the inner sheet material 4X in the longitudinal direction of the sheet material so as to follow the inner surface of the center sheet material 24X.

In steps i-iii) and i-iv), as shown in Figs. 10 and 11, both side portions of the first and second sheet original rolls 2, 3X may be folded inward, and then the center sheet original roll 24X (and inner sheet original roll 4X) may be inserted between both side portions, or as shown in Fig. 12, the center sheet original roll 24X (and inner sheet original roll 4X) may be supplied and conveyed to the widthwise center of the first and second sheet original rolls 2, 3X, and then both side portions of the first and second sheet original rolls 2, 3X may be folded inward. In either case, the folded both side portions of the first and second sheet original rolls 2, 3X become the side sheet original rolls 25X, 25X, and the unfolded center portion becomes the second sheet original roll 3X.

The order of steps ii) through vi) can be changed as appropriate within the scope of production feasibility. Furthermore, steps i) through v) may be performed by continuously transporting the sheet material, or may be performed by intermittently transporting the sheet material.

Thus, according to the first manufacturing method, both sides of the tube are cut off in a triangular shape, which results in loss, but the longitudinal direction (feed direction) of the second sheet roll 3X and the direction of the opening strip 34 are aligned. Therefore, in the food packaging bag 1, the opening strip 34 is aligned with the tearing direction of the second sheet 3. Therefore, according to the food packaging bag 1 manufactured according to the first manufacturing direction, it is possible to improve the ease of opening.

In addition, for the invention relating to the first manufacturing method, the requirement that the distance between the two boundary lines B, B that divide the first sheet 2 into three regions, the central portion 22 and the two side portions 23, 23, be smaller than the width of the top joint portion 11 is not essential.

<Second manufacturing method>
The second manufacturing method is shown in Figures 16 to 22. The second manufacturing method includes:
i) preparing a first sheet 2X as shown in FIG. 16 and FIG. 17;
ii) preparing a second sheet 3X as shown in FIG.
iii) as shown in FIG. 19, a step of overlapping the first sheet original roll 2X and the second sheet original roll 3X while inserting the inner sheet 4 between the first sheet original roll 2X and the second sheet original roll 3X at a fixed pitch along the longitudinal direction of the sheet original rolls;
iv) forming a joint portion that will become the top joint portion 11 in the overlapping sheets in a band shape along the longitudinal direction of the sheet raw roll and in a staggered pattern in the longitudinal direction of the sheet raw roll, as shown in FIG.
v) forming a joint portion that will become the side joint portion 12 in the overlapped sheets in a band shape obliquely relative to the width direction of the sheet raw material and in a staggered pattern in the longitudinal direction of the sheet raw material, as shown in FIG.
vi) as shown in FIG. 22, cutting the overlapped sheets obliquely along the widthwise middle of the joint that will become the side joint 12.
Furthermore, the second manufacturing method includes:
vii) forming the notch 14 as shown in FIG.

Step i) is as shown in FIG.
ii) a step of alternately supplying sheets to be the center sheet 24 and the side sheets 25 in the sheet width direction;
i-ii) overlapping the side edge of the sheet to be the center sheet 24 with the side edge of the sheet to be the side sheet 25;
i-iii) forming a joint 27 in the overlapping portion along the longitudinal direction of the sheets.

Alternatively, step i) may be performed as shown in FIG.
ii) a step of supplying sheets to be the side sheets 25 at a constant pitch along the width direction of the sheet raw material and along the longitudinal direction of the sheet raw material on the outer surface of the central sheet raw material 24X;
i-ii) forming joints 27 along the longitudinal direction of the sheets at the overlapping portions of the side edges of the central sheet raw material 24X and the sheets that will become the side sheets 25. The food packaging bag 1 manufactured through the steps of FIG. 17 has the shape shown in FIG. 23.

Step ii) is as shown in FIG.
ii-i) attaching an opening strip 34 to the inner surface of the second sheet roll 3X at a fixed pitch along the width direction of the sheet roll and along the longitudinal direction of the sheet roll;
ii-ii) forming cut lines 32 in a staggered pattern in the longitudinal direction of the sheet material on the opening strip 34.

The order of steps iv) through vii) can be changed as appropriate within the scope of production feasibility. In addition, steps i) through vi) may be performed by continuously transporting the original sheet, or may be performed by intermittently transporting the original sheet.

In this way, according to the second manufacturing method, trapezoidal food packaging bags 1 are manufactured so that they are oriented transversely to the longitudinal direction of the sheet material and alternate in opposite directions. This makes it possible to eliminate or reduce sheet loss.

In addition, for the invention relating to the second manufacturing method, the requirement that the distance between the two boundary lines B, B that divide the first sheet 2 into three regions, the central portion 22 and the two side portions 23, 23, be smaller than the width of the top joint portion 11 is not essential.

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

In the above embodiment, the side portion 23 (side sheet 25) of the first sheet 2 and the second sheet 3 are paper sheets made of a laminated sheet of paper and plastic. However, the present invention is not limited to this. In short, the side portion of the first sheet and the second sheet may be any type of paper sheet as long as the paper sheet has heat-welding properties on the inner side.

In the above embodiment, the distance W27a between the inner edges of the two joints 27, 27 is smaller than the width W11 of the top joint 11, and the distance W27b between the outer edges of the two joints 27, 27 is larger than the width W11 of the top joint 11 (W27a<W11<W27b). As a result, the joint 27 is bent to form an angled column (see FIG. 8). However, the present invention is not limited to this. For example, as shown in FIG. 24 and FIG. 25, the distance WB between the two boundary lines B, B may be narrowed so that the distance W27b between the outer edges of the two joints 27, 27 matches the width W11 of the top joint 11. In this case, the outer edge of the joint 27 is located at the position of the fold line of the front portion 6a and the side portion 6b of the food package 6. The joint 27 is a portion that is further increased in rigidity by the joining. Therefore, the side sheet 25 is neatly folded along the outer edge of the joint 27.

In the above embodiment, the central sheet 24 is disposed on the inner surface side of the side sheet 25. However, the present invention may be reversed. That is, as shown in FIG. 26, in the overlapping portion 26, the side edge portion of the side sheet 25 may be disposed on the inner surface side of the side edge portion of the central sheet 24, and the side edge portion of the central sheet 24 and the side edge portion of the side sheet 25 may be overlapped so that the inner surface of the side edge portion of the central sheet 24 faces the outer surface of the side edge portion of the side sheet 25. In this case, the side sheet 25 has heat-welding properties on the outer surface side in addition to the heat-welding properties on the inner surface side.

In the example shown in FIG. 26(a), like FIG. 25(b), the distance W27b between the outer edges of the two joints 27, 27 coincides with the width W11 of the top joint 11. In the example shown in FIG. 26(b), the distance W27a between the inner edges of the two joints 27, 27 coincides with the width W11 of the top joint 11. In both cases, the side edges of the joints 27 are located at the fold lines of the front portion 6a and side portion 6b of the food package 6. Therefore, the side sheets 25 can be neatly folded along the side edges of the joints 27, which have high rigidity.

In the above embodiment, the opening strip 34 and the inner sheet 4 are arranged over the entire length of the first sheet 2 from one end to the other end of the first sheet 2. However, the present invention is not limited to this. For example, as shown in FIG. 27, the opening strip 34 and the inner sheet 4 may be arranged to have a length shorter than the entire length of the first sheet 2. This food packaging bag 1 can be manufactured by the second manufacturing method.

In the above embodiment, the opening means is a strip for opening. However, the present invention is not limited to this. For example, various known opening means can be used, such as perforations, half cuts (half-cut lines), or a combination of these with a strip for opening.

In addition, terms that specify a shape, part, or state, such as "trapezoid," "triangular," "rectangular," "rectangular," "straight line," "center," "end," "side," "coincident," "same," "parallel," and "orthogonal," in this invention include not only the thing itself, but also the concept of "approximately" which means something close to or similar to it.

In the above embodiment, the food is a sandwich. However, the food to be packaged may be Western confectionery such as cake, Japanese confectionery such as castella, bread, rice-based processed foods such as rice balls, etc., as long as it can be placed in a food packaging bag, and the type of food is not particularly limited.

The center sheet used in food packaging bags is not limited to being made of a plastic sheet (plastic film). For example, it may be a paper sheet (film) or a sheet (film) made of other materials. That is, in the present invention, the center is not limited to being transparent, but may be translucent or opaque. In the present invention, the sheet is not limited to being a thickness, but is a concept that includes a film.

1...food packaging bag, 10...bag body, 11...top joint, 12...side joint, 13...opening, 14...notch, 15...header, 2...first sheet, 2, 3X...first and second sheet rolls, 20...body, 21...tip, 22...center, 23...side, 24...center sheet, 24X...center sheet roll, 25...side sheet, 25X...side sheet roll, 25Xa...side edge, 26...overlap, 27...joint, 3...second sheet, 3X...second sheet roll, 30...body, 31...tip, 32...score line, 33...opening strip, 34...opening strip, 4...inner sheet, 4X...inner sheet roll, 4a...side edge, 5...sandwich, 6...food package, 6a...front, 6a1...main, 6a2...side, 6b...side, 6c...back, 7...tape, B...boundary, W11...width of top joint 11 (length of inner edge of top joint 11), WB...distance between two boundary lines B, B (width of center 22), W27a...distance between inner edges of two joints 27, 27, W27b...distance between outer edges of two joints 27, 27, W4...width of inner sheet 4

Claims (6)

A food packaging bag is provided which is formed by overlapping a first sheet having a shape in which one end side is wider than one end side in a first direction with a second sheet having the same shape as the first sheet and an opening means along the first direction, the bag body being sealed on three sides by a top joint at one end and side joints at both sides, with the other end side being an opening, and a header portion formed by protruding pieces of each sheet protruding from the top joint,
The first sheet is divided into three regions, a central region and two side regions, by two boundary lines spaced apart in a second direction perpendicular to the first direction;
A paper sheet is used for the side of the first sheet and the second sheet,
The distance between the two boundary lines is smaller than the width of the top joint of the food packaging bag. 2. The food packaging bag according to claim 1, wherein the side joint portion is formed in a strip shape of a predetermined width along the side edge of the bag body and the side edge of the header portion. The first sheet includes a central sheet and two side sheets made of paper, and includes a joint portion at the overlapping portion between the side edge of the central sheet and the side edge of the side sheet;
The central sheet is formed by removing the overlapping portions of both side edges from the central sheet, and the central sheet is formed by removing the overlapping portions of both side edges from the central sheet.
The food packaging bag according to claim 1 or 2, wherein the side sheets form the sides of the first sheet. The food packaging bag according to claim 3, further comprising an inner sheet having a width smaller than the distance between the inner edges of the two joints and disposed on the inner surface of the central sheet. A method for manufacturing a food packaging bag comprising: a first sheet having a shape that is wider at one end side than at the other end side in a first direction; and a second sheet having the same shape as the first sheet and an opening means along the first direction, the bag body being sealed on three sides by a top joint at one end and side joints at both sides, with the other end side being an opening; and a header portion composed of protruding pieces of each sheet protruding from the top joint,
A process for producing a tube in which a portion in a circumferential direction has a predetermined width and the other portion is made of a paper sheet, the portion in the circumferential direction being flattened so as to be located at a center portion of one surface;
forming a band-like joint portion on the tube to be the top joint portion along the width direction of the tube;
forming a joint portion for the tube in a band shape obliquely relative to a side edge of the tube;
cutting the tube in a width direction at a tip position of a portion that will become a header portion;
and cutting the tube obliquely along a widthwise middle position of the joint that will become the side joint. The process for making the tube is as follows:
A step of conveying a belt-shaped central sheet raw material and first and second sheet raw materials made of paper sheets and wider than the central sheet raw material along a longitudinal direction of the sheet raw material;
A step of overlapping a side edge portion of the central sheet raw material with side edge portions of the first and second sheet raw materials;
The method for producing a food packaging bag according to claim 5, further comprising the step of forming a joint at the overlapping portion along the longitudinal direction of the raw sheet.

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