JP2004292028A - Self-supporting flat bag and making method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a self-supporting flat bag, which has a flat cylinder with looped both sides and a bottom gusset under the flat cylinder, and can be opened widely into a shape like the horizontal section of a pillow package and to give a bottom shape of boat form, hexagon, or square, and provide a making method for the flat bag. <P>SOLUTION: The self-supporting flat bag has the bag body flat cylinder forming a front face and a back face, and a bottom flat cylinder, whose both side edges are sealed together so as to make a surface having heat sealability face the outside and whose inner surface upper edges are heat glued together via a partly applied low temperature heat adhesive. The bottom flat cylinder is included in the bag body flat cylinder on an under part thereof so that the looped both side edges of the bottom flat cylinder is inscribed with that of the bag body flat cylinder, where the lower edges of both cylinders are sealed together at the bag bottom. Also, the linear portions on the bottom flat cylinder that start from the upper ends of its both sides to go down at an angle of 45 degrees to reach the bag lower end is sealed on the bag body flat cylinder. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
[Industrial applications]
The present invention relates to a self-supporting flat bag which is provided with a bottom gusset at the lower portion of a flat cylinder having loops on both sides and can be opened greatly in a boat, square or round bottom shape, and a bag manufacturing method thereof.
[0002]
[Prior art]
Conventional pouches are, for example, as disclosed in Japanese Patent Application Laid-Open No. 9-254997, in which both side edges of a front part and a rear part are sealed and connected in a palm-shape manner, and a front part and a rear part sandwiching a bottom gusset are provided. The lower side edges are connected to each other through holes formed in the bottom gusset, so that the bag can be opened in a boat-shaped bottom shape.
[0003]
[Problems to be solved by the invention]
The conventional pouch can be opened in a boat-shaped bottom shape and has self-sustainability, but the both sides of the front part and the rear part are sealed and connected in a palm-shape manner, and the front part sandwiching the bottom gusset The lower side edges of the rear surface and the rear side are connected through a hole provided in the bottom gusset and are flat, so that the bag does not open greatly.
For this reason, the conventional pouch is not suitable for packaging an object to be packaged which requires a large volume.
If the pouch is opened wide like the horizontal cross-sectional shape of the pillow package, it will be suitable for packaging a large volume packaged object.
On the other hand, a pillow package does not have the independence like a pouch.
[0004]
The invention of the present application is provided with a gusset for a bottom surface at the bottom of a flat cylinder having loops on both sides, and a single wrapping material can be closed and opened greatly like a cross-sectional shape of a pillow package horizontally cut into a circle. It is an object of the present invention to provide a self-supporting flat bag and a method for manufacturing the same, which can be opened to a boat, square or round bottom shape which can be expanded more than conventional pouches.
[0005]
[Means for Solving the Problems]
The invention described in [Claim 1] is characterized in that an inverted pocket-shaped bottom gusset having loops on both sides is accommodated in a lower portion of a flat cylinder having loops on both sides, and bottom heat sealing is performed. Features a self-supporting flat bag.
The invention according to claim 2 is for the main body constituting the front part and the rear part of the bag in which the edges on both sides are sealed and connected so that the heat-sealing surface comes to the inner surface of the laminated packaging material. The flat tube and the laminated packaging material are heat-bonded with a low-temperature heating adhesive in which the edges on both sides are sealed and connected in an envelope-attached type, and the upper edges on the inner surface are part-coated so that the surface with heat sealing properties is on the outer surface. It has a flat cylinder for the bottom part
The flat tube for the bottom portion is housed in the lower part of the flat tube for the main body, with the loop-shaped both side edges of the flat tube for the bottom portion inscribed in the loop-shaped both edges of the flat tube for the main body, and below the flat tube for the bottom portion. The edge and the lower edge of the flat cylinder for the main body are provided with a bottom seal connection, and the line portion inclined downward at 45 degrees from the upper end on both sides of the flat cylinder for the bottom surface to the lower end of the bag is formed with respect to the flat cylinder for the main body. It is intended to provide a self-supporting flat bag, which is connected by a seal or a side edge of a loop on both sides of a flat tube for a bottom portion is sealingly connected to a side edge of a loop of a flat tube for a main body. .
[Claim 3] The invention according to claim 3, wherein the continuous bottom laminate packaging material has a heat-sealing surface on the outer surface, and one edge is overlapped with the other edge in an envelope-pasted state. A continuous flat cylinder for the bottom is made by bonding with the coated heating adhesive, and then the continuous flat cylinder for the bottom is squeezed and heated with a pair of heat sealers for each required pitch to end the heated adhesive part-coated on the inner surface. Seal and cut the center of the seal width to form a pillow type closed flat bag for the bottom,
Then, the continuous laminated packaging material for the main body is intermittently run at a required pitch, and at the time of intermittent stop, the closed flat bag for the bottom surface is stacked on the center of the width of the heat-sealing surface of the laminated packaging material for the main body on the upstream side of the former. One end edge of the end sealed of the closed flat bag for the bottom is temporarily attached and welded to the continuous laminated packaging material for the main body,
Next, the continuous laminated packaging material for the main body, to which the closed flat bag for the bottom surface is temporarily attached and welded, so that the closed flat bag for the bottom surface is in sliding contact with the former, is hung on the former, and both side portions of the continuous laminated packaging material for the main body are bottomed. The closed flat bag is folded so as to wrap it, and the both side edges of the continuous laminated packaging material for the main body are sealed and connected to form a continuous flat cylinder for the main body, and both loop-shaped edges of the closed flat cylinder for the bottom portion are formed of the continuous flat cylinder for the main body. In the state inscribed on both sides of the loop,
Then, the lower portion of the bottom of the closed flat tube for the bottom portion and the lower edge of the continuous flat tube for the main body are squeezed and heated by a pair of heat sealers on the adjacent portion closer to the center than the temporary welding portion of the closed flat bag for the bottom. A bottom seal connection, and a line part inclined downward at 45 degrees from the upper end on both sides of the closed flat cylinder for the bottom part to the lower end of the bag is sealingly connected to the continuous flat cylinder for the main body,
Next, the continuous flat cylinder for the main body is cut slightly downstream from the end of the temporary welding portion of the closed flat bag for the bottom to make the bag upper end opening, and at the time of the upstream of the temporary welding portion. On the other hand, the present invention provides a self-supporting flat bag manufacturing method, characterized in that a continuous flat cylinder for a main body and a closed flat bag for a bottom surface are cut to form a bottom surface portion capable of developing the next bag in a plane. .
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the self-supporting flat bag described in [Claim 1] and [Claim 2] and the method for manufacturing the self-supporting flat bag described in [Claim 3] will be described with reference to FIG.
A bag P1 shown in FIG. 1 (a) is a self-supporting flat bag according to the embodiment, which is provided with a flat tube 2A for a bottom portion at a lower portion of the flat tube 1 for a main body having loops on both sides. It has the same autonomy as a pouch bag.
As shown in FIG. 1 (b), the bag P1 shown in FIG. 1 (a) has the heat-sealing property of the laminated packaging material 1A ″ having only one surface for forming the main body flat tube 1 having the heat-sealing property. The flat tube 2A for the bottom portion is superimposed on the surface, and both side portions of the stacked packaging material 1A "are indicated by arrows B from the vertical lines 7a and 7b which are on both sides of the flat tube 2A for the bottom portion of the laminated packaging material 1A". And the end edges are overlapped with each other to form an envelope-attached type, and a back-sealing seal 5 is provided for the seal connection, and the lower edge of the flat tube 2A for the bottom portion and the lower edge of the flat tube 1 for the main body are bottom-sealed. 3 and a line portion inclined downward at 45 degrees from the upper end on both sides of the flat tube 2A for the bottom portion to the lower end of the bag is provided with the inclined seal connections 4 and 4 to the flat tube 1 for the main body. .
When the inclined seal connections 4 and 4 are opened when the gap between the webs is a dead space with the corner portions of the flat tube 2A for the bottom portion and the flat tube 1 for the main body substantially similar to a single web, The developed shape of the flat cylinder 2A for the bottom portion plays a role of providing a boat-shaped, square or round bottom shape. The inclined seal connections 4, 4 are not necessarily limited to an inclination of 45 degrees and may be curved to give a boat-shaped or round bottom shape instead of a straight line.
At the upper ends of the inclined seal connections 4, 4, in order to prevent the pulling by welding of the flat tube 1 for the main body and the flat tube 2 A for the bottom portion from appearing on the flat tube 1 for the main body, the flat tube 2 for the bottom portion is required. The bottom flat tube 2A is housed in the lower part of the main body flat tube 1 so that the two side edges of the loop shape are inscribed with the two side edges of the loop shape of the main body flat tube 1, and the inclined seal connections 4 and 4 are provided. Good to be. Instead of the inclined seal connections 4, 4, the side edges of the loops on both sides of the flat tube for the bottom portion may be sealingly connected to the side edges of the loops of the flat tube for the main body.
The back sticker 5 is not of the envelope type but may be of the gasket type, or may be connected with a double-sided heat-sealing adhesive tape. In the case of an envelope-attached type of seal connection, the overlapping surface of both side edges of the laminated packaging material 1A "is part-coated with a heating adhesive or a packaging material having double-sided heat sealing is used for the laminated packaging material 1A". .
[0007]
The flat tube 2A for a bottom portion shown in FIG. 1 (b) is folded on both sides such that the heat-sealing surface comes to the outer surface of the laminated packaging material having only one surface, and the two sides 2a, 2b It is a loop, and the edges on both sides are sealed and connected so as to form an envelope-attached back sticker 2d near the center of the width and the top seal 2c is formed by a low-temperature heating adhesive whose inner upper edges are part-coated. Upside down bag shape which is heat bonded.
The flat tube 2A for the bottom portion shown in FIG. 1B is on the opposite side so that the back sticker 2d does not overlap the back sticker 5 of the flat tube 1 for the main body.
The flat bottom cylinder 2A shown in FIG. 1 (b) may use a laminated packaging material having double-sided heat sealability. In this case, the portion of the back seal and the top seal 2c are provided on the inner surface side. Except for coating the release agent.
[0008]
The bag P1 shown in FIG. 1 (a) sucks and holds the upper and lower portions of the front and rear portions of the flat tube 1 for the main body by using vacuum pads (not shown) opposed to the upper and lower sides, respectively. As shown in FIG. 1 (b), when the middle part of the flat cylinder 2A for the bottom part is separated until it becomes flat, the bottom shape and the upper opening can be opened greatly in a boat shape. The middle part of the cylinder 2A is kept flat, and as a whole, it becomes a boat bottom shape that is larger than the boat bottom shape of the conventional pouch, and the self-sustainability is largely secured. When the top seal 8 is applied by closing the opening edges flat, the form except for the bottom becomes the same form as the pillow package without vertical seal ribs, and a larger accommodation space can be secured than in the conventional pouch.
[0009]
Further, the bag P1 shown in FIG. 1A has a box-shaped vacuum pad (not shown) in which the front portion and the rear portion of the flat tube 1 for the main body are sucked and held in a large rectangular shape, and is shown in FIG. 1C. As described above, when the flat tube 2 for the bottom portion is separated to the maximum extent until it becomes flat, the bag can be opened so that both sides of the front portion and both sides of the rear portion form a square bottom bag forming a side portion.
After storing the articles to be packaged, put the side gussets, close the opening edges flat and apply a top seal to obtain a square bottom bag packaging form.
[0010]
In this packaging form, a skirt is formed at the lower end of the bag. This skirt is a seal rib for the entire lower edge of the flat tube 1 for the main body and the entire lower edge of the flat tube 2A for the bottom portion.
There is no vertical hem (folded line) on all sides of the skirt. This is not the case if you attach hem in advance.
In the case of this packaging form, both sides of the flat cylinder 2A for the bottom portion are superposed portions of right-angled isosceles triangles, and are pockets when viewed from below the bottom surface. Therefore, after the packaged material is accommodated, the point heat sealer is pressed from the outside onto the overlapping portion of the right-angled isosceles triangles on both sides to weld the overlapping portion, and the pocket is eliminated, whereby the square bottom shape is stabilized. Therefore, it is preferable to process at an appropriate stage.
[0011]
FIG. 2 is an explanatory view showing a method of manufacturing the flat tube 2A for the bottom part shown in FIG. 1B.
FIG. 2A shows a roll film of the laminated packaging material 2A for forming the flat tube 2A for the bottom part shown in FIG. 1B. The laminated packaging material 2A 'has heat sealing properties only on one side, and has a low temperature heating part coat 21a, 21a,. A low temperature heating adhesive part coat 21b is provided on the right side edge in the figure, and a low temperature heating adhesive part coat 21c is provided on the other side edge (the right side edge in the figure) of the surface having heat sealing properties. Have been. By folding both sides of the folding lines 21d and 21e of the laminated packaging material 2A 'so that the surfaces having no heat sealing property, that is, the part coats 21a, 21a,. As shown in FIG. 2B, the edges on both sides of the laminated packaging material 2A 'where the part coats 21b and 21e are provided are overlapped and heated at a required temperature to form an envelope-attached back sticker 22a. When the continuous flat cylinder 22 is formed by sealing and cutting at each part coat 21a as shown by reference numerals 12 and 13, the flat cylinder 2A for the bottom portion can be manufactured, and mass production can be easily performed.
[0012]
FIG. 3 shows an embodiment of the method for producing a self-supporting flat bag according to claim 3, wherein the self-supporting flat bag capable of mass-producing the bag shown in FIG. The following shows the bag making method.
In FIG. 3, reference numeral 30 denotes an inverted isosceles trapezoidal former inclined at a required angle, reference numeral 31 denotes a rectangular former connected to the downstream side of the inverted isosceles trapezoidal former 31, and reference numeral 31a denotes an upper surface of the rectangular former 31. Reference numeral 32 denotes a film guide roll, reference numeral 33 denotes a first film pull-in roll, reference numeral 34 denotes a second film pull-in roll, reference numeral 42 denotes a heat sealer for attaching a palm. 35 is a bottom heat sealer, 36 is a double cutter, 37 is a horizontal fixing plate, 38 is a temporary sealing device, 39 is a vacuum pad of a pickup device, and 40 is a film guide bar.
[0013]
Then, the laminated main body packaging material 1A 'having only one surface having heat sealing property is hung on the horizontal fixing plate 37 so that the surface having heat sealing property is the upper surface, and is wound around the upper side of the film guide roll 32. The film guide bars 40 and 40 hang over the lower surfaces of the inverted isosceles trapezoidal former 30 and the rectangular former 31 in close contact with the lower surface of the inverted isosceles trapezoidal former 30, and leave the two sides of the laminated packaging material 1 </ b> A ′ for the main body. Is folded back so as to cover the upper surface of the rectangular former 31, and the both side edges of the main body laminated packaging material 1A 'are raised by the action of the film edge rising guide 31a, and are joined at the downstream side. The film is drawn by sandwiching the film between the film drawing rolls 33 and 33, and when the intermittent running is stopped, the film is applied by the heat sealers 42 and 42 for attaching the palm. Create a continuous flat tube 1A for the body is subjected to back lined seal of seal type.
[0014]
On the other hand, at another position, a continuous flat cylinder 22 for the bottom shown in FIG. 2 (c) is made, and cut at the center of the width of each part coat 21a from the lines indicated by reference numerals 14 and 15 to cut the center of the seal width to form a pillow. A closed flat bag 2B for a bottom type is made.
The continuous flat cylinder 22 for a bottom surface illustrated in FIG. 2C is manufactured in the same manner as the continuous flat cylinder 22 for a bottom surface illustrated in FIG.
[0015]
Then, as shown in FIG. 3, the closed flat bag 2B for the bottom surface is sucked and held by the vacuum pad 39 of the pickup device, and the laminated packaging material 1A for the main body in which the closed flat bag 2B for the bottom surface is hung on the horizontal fixing plate 37. When the intermittent traveling is stopped, the closed flat bag 2B for the bottom surface is put on the laminated packaging material 1A for the main body when the intermittent traveling is stopped by the temporary sealing device 38 provided below the horizontal fixing plate 37 so as to overlap the surface having the heat sealing property of p Temporarily attach the point seal indicated by.
The closed flat bag 2B for the bottom temporarily attached to the laminated packaging material 1A 'for the main body is in sliding contact with the lower surfaces of the inverted isosceles trapezoidal former 30 and the rectangular former 31, but the downstream edge of the closed flat bag 2B for the bottom is temporarily. It is not turned up because it is attached.
The width dimension of the closed flat bag 2B is determined and precisely determined so that the ends of the loops on both sides of the closed flat bag 2B for the bottom face are precisely positioned at half the height (thickness) dimension of the side surface of the rectangular former 31. Is temporarily attached.
[0016]
When the closed flat bag 2B for the bottom surface passes through the lower surface of the rectangular former 31, the closed flat bag 2B for the bottom comes into close contact with the bag rear surface portion which is a folded portion on both sides of the laminated packaging material 1A 'for the main body, and the closed flat bag 2B for the bottom surface has a loop shape. Are brought into a state of being inscribed in the loop-shaped side edges of the continuous flat cylinder for main body 1A. If there is even a slight gap, the width of either the closed flat bag 2B for the bottom surface or the continuous flat cylinder 1A for the main body is adjusted.
[0017]
After the loop-shaped both side edges of the closed flat bag 2B for the bottom come into intimate contact with the both side edges of the loop of the continuous flat cylinder 1A for the main body, the middle of the temporarily welded portion of the closed flat bag 2B for the bottom. At the time of stoppage of the intermittent running, the adjacent portion closer to the end is squeezed and heated by a pair of heat sealers 35 to apply the bottom seal 3 shown in FIG. 1A to the closed flat bag 2B for the bottom surface and the continuous flat cylinder 1A for the main body. 1 (a), the line portion inclined downward at 45 degrees from the upper end on both sides of the flat cylinder for the bottom part to the lower end of the bag is squeezed and heated by the inclined seal heat sealer 35a formed integrally with the heat sealer 35. Seal connections 4 and 4 are made.
[0018]
Lastly, when the intermittent running is stopped, the two-section cutter 36 cuts a part of the bottom of the closed flat bag 2B slightly downstream from the end of the temporary welding portion to form a bag upper end opening. By cutting off the case on the upstream side and cutting off excess (closed edge on the downstream side of the closed flat bag 2B for the bottom surface), the closed flat bag 2B for the bottom surface can be flattened as shown in FIG. By changing to the flat cylinder 2A for use, a self-supporting flat bag P1 shown in FIG.
[0019]
FIG. 4 shows an embodiment of the method for producing a self-supporting flat bag according to claim 3, wherein the self-supporting flat bag capable of mass-producing the bag shown in FIG. The following shows the bag making method.
4, the same reference numerals are given to the same components as those in FIG. Since the back sticker is an envelope sticker, the overlapping portion between both edges of the packaging material is pressed by the heat seal bar 41 to perform the back stick seal. Reference numeral 42 denotes a film guide roll.
[0020]
The invention of the present application also includes a self-supporting flat bag which is a back-sticking seal in which the edges of the packaging material are attached to each other and a double-sided heat-sealing sealing tape is adhered to the inside thereof, and a method for manufacturing the same.
[0021]
The self-supporting flat bag of the present invention mainly uses a laminated film mainly composed of plastic, and examples of the configuration include the following.
(1) Biaxially stretched nylon film 15 μm / adhesive / LLDPE film 70 μm (outer layer / inner layer)
(2) Biaxially stretched nylon film 15 μm / adhesive / uniaxially stretched or biaxially stretched PP film / adhesive / LLDPE film (outer layer / intermediate layer / inner layer)
(3) PET film 12 μm / LLPDE 20 μm (outer layer / inner layer)
(4) AL 20 μm / LLPDE 70 μm (outer layer / inner layer)
(5) PET / SiOx 12 μm / LLPDE 100 μm (outer layer / inner layer)
(6) O-PA.SiOx 15 μm / LLPDE 80 μm (outer layer / inner layer)
(7) OPP 20 μm / PET / SiOx 12 μm / LLPDE 50 μm (outer layer / intermediate layer / inner layer)
(8) O-PET 12 μm / AL 9 μm / LLPDE 70 μm (outer layer / middle layer / inner layer)
(9) Paper / LLPDE 50 μm (outer layer / inner layer)
It is not limited to these.
[0022]
【The invention's effect】
As described above, according to the self-supporting flat bag according to [claim 1] or [claim 2],
The bottom of the flat cylinder with loops on both sides accommodates an inverted pocket-shaped bottom gusset with loops on both sides, and the bottom is heat-sealed. A self-supporting flat bag that can be opened in a boat, square, or round bottom shape that can be opened greatly because one wrapping material is closed in a loop like a cross-section and expands more than conventional pouches. Can be provided.
According to the method for manufacturing a self-supporting flat bag described in [Claim 3], the self-supporting flat bag described in [Claim 1] or [Claim 2] can be stably and reliably mass-produced.
[Brief description of the drawings]
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a method for producing a self-supporting flat bag and a bag alone according to [claim 1] and [claim 2], wherein FIG. 1 (a) is a front view of the self-supporting flat bag, and FIG. Fig. 1 (c) is a front view showing a state in which a self-supporting flat bag is being formed, and Fig. 1 (c) shows a state in which the self-supporting flat bag is opened so as to have a ship bottom shape, and a state in which an object to be packaged is accommodated and a top seal is applied. FIG. 1D is a perspective view showing a state in which the self-supporting flat bag is opened so as to have a square bottom shape, and a state in which an object to be packaged is accommodated and a top seal is applied.
FIG. 2 shows a manufacturing process diagram of a flat tube for a bottom portion.
FIG. 3 is an embodiment of the method for producing a self-supporting flat bag according to claim 3, wherein the self-supporting flat bag capable of mass-producing the bag shown in FIG. FIG.
FIG. 4 relates to an embodiment of the method for producing a self-supporting flat bag according to claim 3, wherein the self-supporting flat bag capable of mass-producing the bag shown in FIG. FIG.
[Explanation of symbols]
P1: a self-supporting flat bag, 1: a flat cylinder for the main body, 2A: a flat cylinder for the bottom, 3 ... a bottom seal connection, 4 ... an inclined seal connection, 5 ... Back sticker, 1A ′, 1A ″: laminated packaging material, 2A ′: laminated packaging material, 21a, 21b, 21c: part coat, 30: trapezoidal former, 31: rectangular former, 35: bottom heat sealer, 36: double cutter, 41: heat seal bar,

Claims (3)

A self-supporting flat bag characterized by receiving a bottom heat seal by housing an inverted pocket-shaped bottom gusset having a loop on both sides at a lower portion of a flat cylinder having a loop on both sides. A flat cylinder for the main body constituting the front part and the rear part of the bag in which the edges on both sides are sealed and connected so that the surface having the heat sealing property of the laminated packaging material comes to the inner surface, and the heat sealing property of the laminated packaging material A flat cylinder for the bottom part which is heat-bonded with a low-temperature heating adhesive in which the edges having both sides are sealed and connected by an envelope-attached type so that the surface having the outer surface comes to the outer surface, and the upper edges of the inner surface are part-coated. Become
The flat tube for the bottom portion is housed in the lower part of the flat tube for the main body, with the loop-shaped both side edges of the flat tube for the bottom portion inscribed in the loop-shaped both edges of the flat tube for the main body, and below the flat tube for the bottom portion. The edge and the lower edge of the flat cylinder for the main body are provided with a bottom seal connection, and the line portion inclined downward at 45 degrees from the upper end on both sides of the flat cylinder for the bottom surface to the lower end of the bag is formed with respect to the flat cylinder for the main body. A self-supporting flat bag, which is connected by a seal or a side edge of a loop on both sides of a flat tube for a bottom portion is sealingly connected to a side edge of a loop of a flat tube for a main body. With the continuous bottom layer packaging material, the heat sealing surface comes to the outer surface and the other edge is superimposed on one edge in the form of an envelope and adhered with a part-coated heating adhesive for the bottom. A continuous flat cylinder is made, then the continuous flat cylinder for the bottom is squeezed and heated by a pair of heat sealers for each required pitch, and the heated adhesives part-coated on the inner surface are end-sealed and the center of the seal width is cut. Form a closed flat bag for the pillow type bottom,
Then, the continuous laminated packaging material for the main body is intermittently run at a required pitch, and at the time of intermittent stop, the closed flat bag for the bottom surface is stacked on the center of the width of the heat-sealing surface of the laminated packaging material for the main body on the upstream side of the former. One end edge of the sealed bottom bag for the bottom is sealed and welded to the continuous laminated packaging material for the main body,
Next, the continuous laminated packaging material for the main body, to which the closed flat bag for the bottom surface is temporarily attached and welded, so that the closed flat bag for the bottom surface is in sliding contact with the former, is hung on the former, and both side portions of the continuous laminated packaging material for the main body are bottomed. The closed flat bag is folded so as to wrap it, and the both side edges of the continuous laminated packaging material for the main body are sealed and connected to form a continuous flat cylinder for the main body, and both loop-shaped edges of the closed flat cylinder for the bottom portion are formed of the continuous flat cylinder for the main body. In the state inscribed on both sides of the loop,
Then, the lower portion of the bottom of the closed flat tube for the bottom portion and the lower edge of the continuous flat tube for the main body are squeezed and heated by a pair of heat sealers on the adjacent portion closer to the center than the temporary welding portion of the closed flat bag for the bottom. A bottom seal connection, and a line part inclined downward at 45 degrees from the upper end on both sides of the closed flat cylinder for the bottom part to the lower end of the bag is sealingly connected to the continuous flat cylinder for the main body,
Next, the continuous flat cylinder for the main body is cut slightly downstream from the end of the temporary welding portion of the closed flat bag for the bottom to make the bag upper end opening, and at the time of the upstream of the temporary welding portion. On the other hand, a continuous flat tube for a main body and a closed flat bag for a bottom surface are cut to form a bottom surface portion capable of flat development of the next bag, and a method for producing a self-supporting flat bag.

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