JP3984228B2 - Bag manufacturing method - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a bag manufacturing method for manufacturing a bottomed rectangular tube-shaped bag, and more specifically, a bag manufacturing method that can be easily manufactured by bending and heat-sealing a packaging material. About.

  Various bottomed cylindrical bags manufactured from plastic films have been proposed. For example, as shown in FIG. 10, a self-supporting bag described in Patent Document 1 includes a rectangular tube-shaped bag main body 110 and a rectangular bottom forming sheet 120 that seals the opening on the bottom side of the bag main body 110. It consists of and.

  In order to manufacture such a self-supporting bag, first, a rectangular tube-shaped bag main body 110 having a pair of flat surface portions 111 and 111 and side surface portions 112 and 112 is formed. Then, the side lines 112 and 112 are folded inward in the shape of a fold to form fold lines 113 and 113. Next, cuts of a predetermined length are made at the four corners on the side that becomes the bottom of the bag body 110.

  Thereafter, as shown in FIG. 11, the plane portions 111 and 111 and the side portions 112 and 112 on the side where the incision is made in the bag main body 110 are bent outward, and the respective inner surfaces are defined as opening surfaces 114, 114. . The opening surfaces 114 and 114 of the side surface portions 112 and 112 are bent in a V shape, and the opening surfaces 114 and 114 and the squares bent in a V shape on the opening surfaces 114 and 114 of the flat surface portions 111 and 111 are folded. The bottom forming sheet 120 having a shape is folded in two and overlapped, and the outer peripheral edge is heat-sealed into a U-shape. Finally, when the portions of the flat surface portions 111 and 111 and the side surface portions 112 and 112 that protrude from the bottom portion forming sheet 120 are excised, a self-supporting bag is completed.

In this self-supporting bag, the top and bottom are inverted, the bottom forming sheet 120 bent into a Λ shape is developed into a flat state, and the overhang portions 130 and 130 that are enlarged on the bottom side are formed. Then, as shown in FIG. 10, the side surface portions 112, 112 of the self-supporting bag are expanded, and the packaged item can be accommodated.
Japanese Patent Laid-Open No. 5-221451

  The self-supporting bag disclosed in Patent Document 1 forms opening surfaces 114, 114... By cutting into four corners of a rectangular tube-shaped bag body 110, and a bottom forming sheet 120 is formed on the opening surfaces 114, 114. Are manufactured by overlapping and heat-sealing the two. Therefore, there is a problem that the bottom forming sheet 120 must be accurately superimposed at a predetermined position on the opening surfaces 114 and 114, and work efficiency is poor.

  Then, this invention makes it a subject to provide the manufacturing method of the rectangular parallelepiped bag which enabled it to manufacture efficiently.

In the bag manufacturing method according to the present invention, the front and back portions and a pair of fold-like side surfaces are formed by bending a sheet-like packaging material having a heat sealing property on the back surface and no heat sealing property on the front surface. Forming a double-end-opening envelope-shaped body, a separation portion provided on one edge side of the double-end-opening envelope-shaped body, and a bottom piece continuous to the front portion between the separation portions and a back surface portion. The bottom piece, the step of making the protruding piece continuous to the side face, the bottom piece continuous to the front face, the bottom pieces of the bottom piece continuous to the back face, and the front face or the back face and both side faces so that the back face of the protruding piece is exposed. A step of spreading the seam sheet having both sides heat-sealable on the boundary between the exposed front part and the back part of the back surface via a heat insulating plate, and folding the bottom pieces. , The back of the tip of both bottom pieces And the step of forming the bottom surface by superimposing the seaming sheet and heat sealing, and removing the heat insulating plate from between the front and back portions and the seaming sheet, A process of heat-sealing the outer peripheral edge where the bottom surface and the front surface, the back surface and the side surface overlap, and the joining sheet projecting from the projecting piece and the bottom surface And a step of excision.

  According to this bag manufacturing method, the bag can be manufactured by a series of flow operations such as folding the packaging material, heat-sealing the packaging materials that overlap each other, and the packaging material and the joining sheet. That is, first, a packaging material is bent, and both ends of the packaging material are heat-sealed to form a double-end opening envelope body composed of a front portion, a back portion, and a pair of fold-like side portions. A separation portion is provided on one edge side of the shaped body. This separation part is provided, for example, about half the width of the side part by notching the boundary line between the side part, the front part and the rear part, or by not heat-sealing both ends of the packaging material. It is done. The space between the separated portions is a bottom piece that continues to the front portion and the back portion, and a protruding piece that continues to the side portion.

  Next, for example, the front part is folded back by the length of the width of the side part from the edge of the bottom piece on the front part side, and at the same time, both projecting pieces project at right angles from each side edge of the open-ended envelope body. By bending both side surfaces of the portion adjacent to the protruding piece, the bottom piece and the back surface of the protruding piece are exposed. Then, not only both the back surfaces of the bottom piece and the projecting piece, but also the back surfaces of the front surface portion, the back surface portion, and the side surface portion adjacent to the projecting piece are exposed.

  Next, the joining sheet | seat which both surfaces have heat-sealability is piled up on the boundary part of both the back surfaces of the exposed front part and back part through a heat insulation plate. The splicing sheet is longer than the width of the open-ended envelope, that is, the width of the front portion and the back portion, and the both end portions of the splicing sheet are located on each protruding piece. The bottom surface portion is formed by superimposing the back surface of the developed tip portion of each bottom piece on such a joining sheet and heat-sealing the joining sheet and the tip portion of each bottom piece in this state. The seam sheet has heat sealability on both sides, but since a heat insulating plate is interposed between the seam sheet and both back surfaces of the front part and the back part, Heat sealing is not performed on both the back surface of the front portion and the back portion.

  And after discharging | emitting a heat insulation plate from between a bottom face part, a front part, and a back part, it folds in half so that the surface may overlap, and a bottom part, a front part, a back part, and a side part overlap. The outer peripheral edge is heat sealed in a U shape. Then, the boundary portion between the bottom surface portion, the front surface portion, and the back surface portion is reinforced like a frame-like collar portion. The seam sheet is interposed at the boundary between the bottom part and the side part, but the seam sheet has heat sealing properties on both sides, so the boundary part between the bottom part and the side part is heated with the seam sheet. Sealed. In addition, although a bottom face part and a side part overlap, both surfaces are not heat-sealed since both surfaces do not have heat sealability.

  And since such a joining sheet | seat and the protrusion piece protrude from the bottom face part, this protruding joint sheet | seat and protrusion piece are excised. The joint sheet can be cut at any time after the bottom surface is formed, and the protruding piece can be cut out after being developed so that the back surface of the protruding piece is exposed. It can also be performed at the point of time.

  The bottom surface portion is formed by providing a separation portion at the boundary line between the side surface portion, the front surface portion, and the back surface portion, and is integrated by a packaging material that is continuous with the front surface portion and the back surface portion. In addition, characters and designs can be printed from the front and back parts to the bottom part so as not to be discontinuous.

Further, in the manufacturing method of the seaming sheet it is preferably being a strip having a width which overlaps the respective front end portions of both the bottom pieces to be in fold returned by a flat continuous surface.

  According to this bag manufacturing method, both bottom pieces are folded back so that the front end portions of both bottom pieces, which are flat continuous surfaces, are heat-sealed with the joining sheet to form a bottom face portion. The sheet is not the same width as the width of the bottom part, but is formed into a band shape having a width that overlaps the tip part of each bottom piece, so that the seam sheet can be saved, and the seam sheet is also a front part. Or it does not need to position correctly so that it may not protrude to the back side, and productivity can be improved.

In the method for producing the bag, the ends in any time step or after forming the opening envelope-like body, said side portions and the front portion side edge portion and overlaps and side portions except the separation portion It is preferable to include a step of heat-sealing the side edge portion where the back portion and the back portion overlap.

  According to this bag manufacturing method, the front part and the rear part sandwich the side part folded in a fold shape, and the side edges of the overlapping back part of the side part and front part and back part are heat sealed. By doing so, a side edge part becomes like a pillar and is reinforced. The side edge part is heat-sealed in a state where the surfaces overlap each other by being folded into a fold shape, but the side edge part of the side part is not heat-sealable because the surface of the side part does not have heat sealability. Without being heat-sealed, the side edges can be developed from a folded state into a flat state. In addition, when heat-sealing a side edge part, the separation part provided without being heat-sealed becomes the length which added the width | variety which heat-seals a side edge part to the length of about the half of the width | variety of a side edge part.

In the method for producing the bag, the packaging material is preferably made of a resin layer having heat sealing property and heat-sealability to the back surface having no base layer from the laminated sheets.

  According to this bag manufacturing method, all or part of the packaging material is constituted by a sheet, and this sheet is formed by laminating a resin layer having heat sealing properties on the back surface of a base layer having no heat sealing properties. Thus, even when the packaging materials are stacked in multiple layers, the overlapping surfaces are not heat sealed, and only the back surfaces can be heat sealed.

In the method for producing the bag, before Symbol open ends envelope-shaped body, bending the sheet to the back surface between the both end edges of the sheet are bonded, it is formed by heat sealing the said end edge portions May be.

  According to this bag manufacturing method, the bag is manufactured from a single sheet in which the resin layer is laminated on the back surface of the base layer. The both edge portions of the sheet are joined at the boundary between the front part or the back part and the side part, or joined at the middle part of the front part or the back part, and the back surfaces of the joined parts are heat-sealed. A double-end open envelope is formed.

  In the bag manufacturing method, a part or all of the packaging material may be formed of a transparent or translucent film.

  According to this bag manufacturing method, a transparent or translucent film is provided on all or any of the front part, the back part, and the side part, so that the contents to be packaged in the bag can be visually observed. become. The packaging material can be composed of only this transparent or translucent film, or it can be composed of the transparent or translucent film and the sheet joined together. In addition, when the packaging material is formed by joining the transparent or translucent film and the sheet by heat sealing, each end edge portion is made to coincide with the side edge portion of the side surface portion, the front surface portion, and the back surface portion. Thus, the operation of heat-sealing the transparent or translucent film and sheet in a range other than the separation portion can be combined with the operation of providing a bonding surface for adhering the side edge portions.

  According to the present invention, a front portion, a rear portion, a side portion, and a bottom portion are formed by a series of flow operations such as heat sealing the tip portions of a pair of bottom pieces formed by bending a sheet-like packaging material with a joining sheet. Since a part is formed, a bag can be manufactured efficiently. Therefore, the bag manufactured by this invention can aim at cost reduction. In addition, since the front part, the back part and the bottom part are formed by a continuous packaging material, it becomes possible to print continuous characters and patterns without misalignment. Can be planned.

  An embodiment of a bag manufacturing method according to the present invention will be described with reference to FIGS.

  In the bag manufacturing method of this embodiment, first, a sheet-like packaging material A is bent to form a double-end opening envelope 20 as shown in FIG. The packaging material A is formed by a single sheet 10 in which a resin layer having heat sealing properties is laminated on the back surface of a base layer having no heat sealing properties. This sheet 10 uses a resin layer having heat sealing properties as the back surface 11 and a base layer having no heat sealing properties as the front surface 12.

  Specifically, such a sheet 10 is composed of a thin paper such as kraft paper or rayon paper whose base layer does not have heat sealability, and food packaging such as polypropylene or polyethylene whose resin layer has heat sealability. Consists of plastics. Alternatively, since the sheet 10 is transparent or translucent, a pet film having no heat sealability may be used as a base layer, and heat-sealable polypropylene may be laminated on the base layer so that the whole is made of plastic. Further, the sheet 10 may be formed of three layers or four or more layers by laminating an aluminum layer or the like for ensuring light shielding properties.

  Such a sheet 10 is bent so as to have a front part 1, a back part 2, and a pair of side parts 3 and 3. And the both-ends opening envelope-like body 20 is formed, for example, when the back surfaces of the both-ends edge parts 13 and 13 of the sheet | seat 10 overlap and heat-seal. Both edge portions 13 and 13 are bent so that the back surfaces 11 and 11 are joined to each other, and are heat-sealed with a narrow width J by a heater (not shown) (the same applies hereinafter) (the heat-sealed portion is indicated by halftone dots). same as below.).

  When heat sealing is performed so that both edge portions 13 and 13 of the sheet 10 become the side edge portion 5 between the back surface portion 2 and the side surface portion 3, a double-end opening envelope 20 as shown in FIG. 1 can be formed. . However, although not shown in the drawing, both end edge portions 13 and 13 of the sheet can be heat-sealed so as to be positioned at the center line of the back surface portion 2 to form a so-called back-attached both-end opening envelope 20.

  In any case, the pair of open end envelopes 20 are flattened so that the pair of side surface parts 3 and 3 are folded in a fold shape, and the front part 1 and the back part 2 overlap each other in a separable manner. In the drawings, the front portion 1 and the rear portion 2 are drawn apart from each other for easy viewing.

  Next, as shown in FIG. 2, the side edge portion 5 in which the side surface portion 3 and the front surface portion 1 and the back surface portion 2 overlap each other is heat-sealed with a thin width J by a heater. By this heat sealing, the side edge 5 is reinforced like a pillar. However, the side edge portion 5 is heated from one end edge of the both-end-opening envelope-like body 20 to at least about half the length (including half the length) of the width H of the side surface portion 3 (see FIG. 8). The side edge 5a in the range up to the length L (= (1/2) H + J) including the sealed width J is not heat-sealed. Therefore, when forming the both-end-opening envelope-shaped body 20, the side edge portions 5 of the back surface portion 2 and the side surface portion 3 are used to heat seal the both edge portions 13 and 13 of the sheet 10 as well. The range of length L from the edge is not heat sealed. In addition, after heat-sealing the both-ends edge parts 13 and 13 of the sheet | seat 10, the side part 3 bent in the shape of a fold is formed, and the side edge part 5 of this side part 3 and the front part 1 is heat-sealed. The both edge portions 13 and 13 of the sheet 10 are heat-sealed twice, but there is no problem.

  However, the sheet 10 is not heat-sealed at both edge portions 13 and 13, the pair of side surface portions 3 and 3 are folded in a crease shape, and the front surface portion 1 and the back surface portion 2 sandwich the side surface portions 3 and 3. In this state, each side edge 5, 5, ... may be heat sealed. Also in this case, all the side edge portions 5, 5... Are heat-sealed except for a range of a length L from one end edge of the double-end open envelope body 20.

  Next, as shown in FIG. 2, separation portions 8a, 8b, 8b, and 8b are provided on the side edge portion 5a side of the envelope body 20 that is open at both ends, which is not heat-sealed. The side edge 5a that is not heat-sealed at both end edges 13 and 13 of the sheet 10 is already provided with a separation portion 8a having a length L, but the other separation portions 8b, 8b, and 8b are provided on the side surface portion 3. It is provided by making an incision with a length H / 2 that is half the width.

  A portion continuous between the front portion 1 and the back portion 2 sandwiched between a pair of separation portions 8b, 8b; 8a, 8b is formed as bottom pieces 4a, 4b, and another pair of separation portions 8b, 8b; 8a, 8b. The portions that continue to the sandwiched side surface portions 3 and 3 are the protruding pieces 9 and 9. Then, a crease K is provided in the width direction so that the surface 12 of the bottom piece 4a can be easily bent at a position separated from the edge of the front portion 1 by the width H of the side surface portion 3. The fold K is formed in a groove shape by pressing a stamping press or a roller from the surface 12 side of the back surface portion 2.

  Next, as shown in FIG. 3, the bottom pieces 4a, 4b and the projecting pieces 9, 9 are developed so that the bottom pieces 4a, 4b and the back surfaces 11, 11. That is, the bottom piece 4a on the front portion 1 side is folded back at the fold K, and the surface 12 of the bottom piece 4a is overlapped with the surface 12 of the front portion 1 that is continuous with the bottom piece 4a (in FIG. 3, it is easy to see). Therefore, they are drawn apart.)

  At the same time, the edges of the projecting pieces 9, 9 are parallel to the long sides of the double-end opening envelope body 20, and the projecting pieces 9, 9 project from the both-side edges of the double-end opening envelope body 20 in a perpendicular direction. The portions adjacent to the protruding pieces 9, 9 of the side surface portions 3, 3 are bent. On both side surfaces 3 and 3, folding lines Q and Q having a U-shaped shape and an inverted U-shaped shape are formed. A line P connecting the vertices of the folding lines Q and Q and a fold line K of the folded front portion 1 and Match. When the front portion 1 is bent at a crease K and the bottom pieces 4a and 4b and the protruding pieces 9 and 9 are unfolded, not only the bottom pieces 4a and 4b and the back pieces 11 and 11 of the protruding pieces 9 and 9, but also the bottom pieces 4a and 4b protrude. The back surface 11 and 11 of the front part 1 and the back part 2 surrounded by the pieces 9 and 9 are also exposed.

  Next, as shown in FIG. 4, a seam sheet 22 having heat sealing properties on both sides is overlapped on the exposed back surfaces 11 and 11 of the front surface portion 1 and the back surface portion 2 through a heat insulating plate 21. Match. The joining sheet 22 is longer than the double-end open envelope state 20, that is, the width D of the front part 1 and the back part 2, and both end parts overlap the protruding pieces 9 and 9. Further, the width of the joining sheet 22 is at least shorter than the width H of the side surface portion 3, and when the bottom pieces 4a and 4b are folded back in a subsequent process, the bottom pieces 4a and 4b become flat continuous surfaces. It is preferable to make it the strip | belt shape which has the width | variety which overlaps with each front-end | tip part.

  Even if a gap is formed between the tip edges of the bottom pieces 4a and 4b, the joint sheet 22 closes the gap so that no gap is generated in the bottom surface portion 4 formed in the subsequent process. . Further, since the joining sheet 22 is formed in a band shape, it is not necessary to align the side edges of the joining sheet 22 so that the side edges do not protrude from the front portion 1 or the back portion 2, and the material can be saved. Can be planned.

  And when the heat insulation plate 21 heat-seal | bonds the said joining sheet 22 and both bottom piece 4a, 4b in a post process, both the back surfaces 11 and 11 of the joining sheet 22 and the front part 1 and the back part 2 heat. In order to prevent sealing, the size is larger than the portion that seals the bottom pieces 4a, 4b and the joining sheet 22. The heat insulating plate 21 is unfolded and positioned on the exposed back surfaces 11 and 11 of the front surface portion 1 and the back surface portion 2, and the unfolded position of the protruding pieces 9 and 9 or the bottom pieces 4a and 4b. Reciprocally move between them.

  After the heat insulating plate 21 and the joining sheet 22 are superposed on the back surfaces 11 and 11 of the front surface portion 1 and the back surface portion 2, as shown in FIG. 5, the front surface portion 1 and the back surface portion 2 and both bottom pieces 4a. , 4b are folded back and the back surfaces 11, 11 are overlapped on the joining sheet 22. Both bottom pieces 4a, 4b are folded at boundary lines N, N between the bottom pieces 4a, 4b and the front portion 1 and the back portion 2. The boundary lines N and N are set at a position having an interval of the width H / 2 that is half of the side surface portion 3 from the end edges of the bottom pieces 4a and 4b. In FIG. 5, the bottom pieces 4a, 4b, the joining sheet 22, and the heat insulating plate 21 are drawn in an inclined manner for easy viewing, but actually they overlap in a flat state.

  The bottom pieces 4a, 4b and the joining sheet 22 thus superposed are heat-sealed by a heater in the unfolded state, and the bottom surface portion 4 is formed. Even if a gap is formed between the tip edges of the bottom pieces 4 a and 4 b that are folded and faced, the gap is closed by the joining sheet 22. The heater is heat-sealed so as to sandwich the surface 12 of both bottom pieces 4a, 4b and the surface 12 of the back surface portion 2, but the back surface 11, 11 of the joining sheet 22, the front surface portion 1 and the back surface portion 2 is insulated. Due to the presence of the plate 21, heat sealing is not performed.

  And after the bottom face part 4 is formed, the heat insulation plate 21 is discharged from between the joining sheet 22 and the front part 1 and the back part 2. Then, the back surface 11 of the bottom surface portion 4 and the back surfaces 11 and 11 of the front surface portion 1 and the back surface portion 2 are overlapped except for the joint sheet 22 portion.

  Next, as shown in FIG. 6, the bottom surface portion 4 and the protruding pieces 9 and 9 are folded in half. As for the bottom face part 4, the front surfaces 12 and 12 overlap, and as for the protrusions 9 and 9, the back surfaces 11 and 11 overlap. And the outer peripheral edge part 6 of the bottom face part 4 is heat-sealed in a U-shape. Then, the back surface 11 of the bottom surface portion 4 and the outer peripheral edge 6 of each of the back surfaces 11, 11,... Of the front surface portion 1, the back surface portion 2, and the side surface portions 3, 3 are heat-sealed in a frame shape with a width J to form a flange portion. By being done, it is reinforced. On the other hand, the side surfaces 3, 3 adjacent to the protruding pieces 9, 9 and the front surface 1 and the back surface 2 are not heat sealed because the surfaces 12, 12 overlap each other.

  Then, when the projecting pieces 9 and 9 projecting from both side edge portions 5 of the front surface portion 1 and the back surface portion 2 and the joining sheet 22 are cut off, the bag is completed. Since this bag is formed by one sheet of packaging material A from the front part 1 and the back part 2 to the bottom part 4, it is possible to print a continuous character or pattern without misalignment.

  The cutting of the protruding pieces 9 and 9 can be performed at any point after the protruding pieces 9 and 9 are unfolded so that the back surfaces of the protruding pieces 9 and 9 are exposed as shown in FIG. Further, the cut-out of the joining sheet 22 can be performed at any time point after the bottom surface portion 4 is formed as shown in FIG.

  Then, when the bottom surface portion 4 folded in half and the side surface portion 3 folded in a fold shape are developed in a flat state, a bottomed cylindrical bag as shown in FIG. 8 is obtained. This bag is in a state in which a collar portion is formed on the outer peripheral edge portion 6 of the bottom surface portion 4, and pillars are formed on the side surface portion 3, the front surface portion 1, and both side edge portions 5, 5 of the back surface portion 2. Therefore, the outer peripheral edge portion 6 and the side edge portions 5 and 5 have a strong structure that is difficult to be torn or torn. In such a bag, for example, food such as rice balls, french fries, and hot dogs and other items to be packaged are packaged.

  Moreover, this bag can accommodate a to-be-contained object in the fall state by sealing an opening part. And since the bottom face part 4 does not overlap the heat-sealed boundary line as in the so-called caramel wrapping, and has a good appearance in which the end edges of the bottom pieces 4a and 4b are abutted, this bag can be placed horizontally. It can display suitably.

  In addition, this invention can be variously changed within the range of the technical matter described in the claim, without being limited to the said embodiment. For example, the packaging material A includes a sheet 10 obtained by bonding a plastic that becomes the back surface 11 and a thin paper that becomes the front surface 12, and a transparent or translucent film (hereinafter referred to as “transparent film”) that has heat sealability only on the back surface 11. .) 30 can be spliced together by heat sealing. The transparent film is formed of a plastic film such as polypropylene or polyethylene.

  In such a packaging material A, for example, as shown in FIG. 9, the transparent film 30 constitutes the entire front surface portion 1 and the bottom piece 4 a, and the sheet 10 constitutes the back surface portion 2, both side surface portions 3, 3, and the bottom piece 4 b. The double-end opening envelope 20 is formed. However, the transparent film 30 may constitute the front part 1 and both side parts 3, 3 or one side part 3, and the sheet 10 may constitute the back part 2 and the bottom part 4 or one side part 3. .

  In any case, the transparent film 30 and the sheet 10 have side edges that are approximately half the length (including half the length) of the width H of the side portion 3 from one end of the double-end-opening envelope 20. Except for the length L (= (1/2) H + J) including the width J obtained by heat-sealing 5, the portions that are not heat-sealed are the separating portions 8a and 8a. A separation portion (not shown) having a length half the width H of the side surface portion 3 by cutting at the boundary line between the front surface portion 1 and the back surface portion 2 on the same side as the separation portions 8a, 8a and the side surface portions 3, 3. After that, since the bag can be manufactured by the same process as described above, the description thereof is omitted.

  In particular, in the case of the double-end opening envelope 20 in which both end portions 13 and 13 of the sheet 10 are so-called back bonding, the side edge portions 5, 5 of the front portion 1, the back portion 2, and the side portion 3. May not be heat-sealed in a strip shape. Furthermore, the front part 1, the back part 2, the side part 3, and the bottom part 4 are names used for convenience, and the bottom part 4 may be located on the side depending on the usage of the bag. Nor.

It is one Embodiment of the manufacturing method of the bag concerning this invention, Comprising: The schematic perspective view which shows an initial state It is one Embodiment of the manufacturing method of the bag which concerns on this invention, Comprising: The schematic perspective view which shows the state in the middle of manufacture It is one Embodiment of the manufacturing method of the bag which concerns on this invention, Comprising: The schematic perspective view which shows the state in the middle of manufacture It is one Embodiment of the manufacturing method of the bag which concerns on this invention, Comprising: The schematic perspective view which shows the state in the middle of manufacture It is one Embodiment of the manufacturing method of the bag which concerns on this invention, Comprising: The schematic perspective view which shows the state in the middle of manufacture It is one Embodiment of the manufacturing method of the bag which concerns on this invention, Comprising: The schematic perspective view which shows the state in the middle of manufacture It is one Embodiment of the manufacturing method of the bag which concerns on this invention, Comprising: The schematic perspective view which shows the state in the middle of manufacture It is one Embodiment of the manufacturing method of the bag which concerns on this invention, Comprising: The schematic perspective view which shows a use condition The schematic perspective view which is different embodiment from the above of the manufacturing method of the bag which concerns on this invention, Comprising: The first state is shown The schematic perspective view which shows the use condition of the conventional bag It is a conventional bag manufacturing method and is a schematic perspective view showing the manufacturing process

Explanation of symbols

A ... Packaging material 1 ... Front part 2 ... Back part 3 ... Side part 4 ... Bottom part 4a ... Bottom piece 4b ... Bottom piece 5 ... Side edge part 6 ... Outer peripheral edge part 8a ... Separation part 8b ... Separation Part 9 …… Projection piece 10 …… Sheet 11 …… Back side 12 …… Surface 20 …… Envelope with open ends 21 …… Insulation plate 22 …… Sealing sheet 30 …… Transparent film

Claims (6)

By folding a sheet-like packaging material having a heat sealing property on the back surface and no heat sealing property on the back surface, a double-ended opening envelope body composed of a front surface portion and a back surface portion and a pair of fold-like side surface portions is obtained. Forming, and
A step of providing a separation part on one edge side of the both-end-opening envelope-like body, a bottom piece continuing to the front part between the separation parts, a bottom piece continuing to the back part, and a protruding piece continuing to the side part;
Developing the front part or the back part and both side parts so that the bottom piece continuing to the front part, both bottom pieces of the bottom piece continuing to the back part and the back of the protruding piece are exposed;
A process of superimposing a seam sheet having heat sealability on both sides via a heat insulating plate on a boundary portion between both exposed front and back surfaces;
Folding both bottom pieces, forming a bottom portion by heat-sealing the back surface of the bottom portion of the both bottom pieces and the joining sheet,
After removing the heat insulating plate from between the front and back portions and the joining sheet, the bottom portion is folded in half so that the surfaces overlap each other, and the bottom portion and the front portion, the back portion and the side portion overlap. Heat-sealing the outer peripheral edge, and
And a step of cutting out the joining sheet projecting from the projecting piece and the bottom surface. The seaming sheet bag according to claim 1, characterized in that there is a strip having a width which overlaps the respective front end portions of both the bottom pieces to be in fold returned by a flat continuous surface Manufacturing method. In any time step or after forming the both end opening envelope-like body, the side with the spacing the side portion other than the portion and the front portion side edge portion and overlaps and side portion and a rear portion are overlapped The method for manufacturing a bag according to claim 1, further comprising a step of heat-sealing the edge portion. The packaging material, the production of bags according to any one of claims 1 to 3, characterized in that the resin layer having heat sealing property and heat-sealability to the back surface having no base layer from the laminated sheets Method. Before SL openings at both ends envelope-shaped body, folding the sheet so that the back surface between the both end edges of the sheet are joined, the said end edge portions to claim 4, characterized in that it is formed by heat-sealing The manufacturing method of the bag as described. The method for manufacturing a bag according to any one of claims 1 to 5, wherein a part or all of the packaging material is made of a transparent or translucent film.