WO2022180986A1 - Bag making method and bag making machine - Google Patents

Abstract

Two web-shaped body materials and gusset materials are used as constituent elements of a bag. These are formed from a single material. This bag making method comprises: heat sealing alternately-stacked body materials and gusset materials with every intermittent conveyance while the materials are sandwiched by heat sealing members; after the heat sealing by the heat sealing members, sequentially manufacturing bags by cross-cutting the body materials and the gusset materials in the width direction of the body materials with every intermittent conveyance of the body materials. The bag making method further comprises, during the heat sealing, blocking a first surface and a second surface which face each other from being heat sealed to each other at one constituent element by means of a release agent interposed between the first surface and the second surface. The release agent is coated on a film constituting the one constituent element in advance. The first surface and the second surface are surfaces serving as the outside of the bag.

Description

Bag-making method and bag-making machine

The present application relates to a bag-making method and a bag-making machine for manufacturing a bag from two web-shaped panel materials and a gusset material.

　Bag making using plastic film is known. For example, a laminate film including a base layer and a sealant layer having a melting point lower than that of the base layer may be used as in Patent Document 1. Also, as in Patent Document 3, a film made of a single material may be used.

In Patent Documents 1 and 2 using a laminate film, welding is performed by bringing two surfaces, both of which are sealant layers, into close contact with each other with a heat sealing member, applying heat and pressure to heat seal these two surfaces. (Heat welding). The heat sealing temperature is set to a temperature at which only the sealant layer melts and the base layer does not melt. This prevents the base layer from melting during heat sealing. This makes it possible to manufacture a bag having a complicated structure including a body portion and a gusset portion, as disclosed in Patent Documents 1 and 2, for example.

In Patent Document 3, which uses a film of a single material, a release agent such as medium ink is applied to a predetermined area on at least one of the inner surface of the first panel material (film) or the inner surface of the second panel material (film). applied. The inner surfaces of these webs are then heat sealed together. The webs are heat sealed to each other in the areas where the release agent is not interposed, but the release agent prevents them from being heat sealed to each other in the areas where the release agent is interposed. By applying the release agent, it is possible to clearly define areas that are not heat-sealed even after the heat-sealing process. Patent Document 4 also uses a release agent to prevent heat sealing between the inner surfaces of the bag.

The techniques disclosed in Patent Documents 3 and 4 can be used to manufacture a bag with a simple structure that includes two body portions but does not include a gusset portion. However, no method has been developed to manufacture a bag having a complex structure including a body portion and a gusset portion made of a single material film.

From the point of view of environmental protection such as recycling, films made of a single material are preferable to laminated films. Accordingly, it is desirable to sequentially manufacture bags that include a single material body and a single material gusset.

WO2019/163496 JP 2015-000568 A JP-A-2005-047041 JP 2014-162520 A

The purpose of the present application is to enable continuous production of a bag including a body portion made of a single material and a gusset portion made of a single material.

SUMMARY OF THE INVENTION According to one aspect of the present application, there is provided a method of making a bag using two web-like panels and a gusset material as bag components. Each of the components is made of a single material.
Said bag-making method is:
intermittently conveying the panel material in the longitudinal direction of the panel material by a conveying device;
The panel material and the gusset material laminated to each other are heat-sealed by sandwiching them with heat-sealing members each time they are intermittently conveyed;
After heat-sealing with the heat-sealing member, the panel material and the gusset material are cross-cut in the width direction of the panel material each time the panel material and the gusset material are conveyed intermittently to manufacture bags sequentially;
During the heat-sealing, the release agent interposed between the first surface and the second surface prevents the first surface and the second surface facing each other in one component from being heat-sealed. wherein the release agent is pre-applied to the film constituting the one component, and the first surface and the second surface are surfaces that are to be the outside of the bag.

The bag-making method may comprise arranging side gusset materials as the gusset materials between the panel members.
When the panel material and the side gusset material are sandwiched between the heat-sealing members and heat-sealed in the width direction of the panel material, the release agent is applied to the first surface and the second surface of the side gusset material facing each other. It may prevent the faces from being heat sealed to each other.

The bag-making method includes: applying the release agent to the first surface of the film; Folding the film in half on both sides of the longitudinal centerline of the film to form the side gusset material.

The bag-making method may comprise disposing a web-like bottom gusset material as the gusset material between the panel members.
When the panel material and the bottom gusset material are sandwiched by the heat-sealing members and heat-sealed in the longitudinal direction of the panel material, the release agent is applied to the first surface and the first surface of the bottom gusset material facing each other. It may prevent the two sides from being heat sealed together.

The bag-making method is
applying the release agent to the web-like film forming one of the panel members and the bottom gusset member;
Folding the web-like film to form the one panel material and the release agent coated bottom gusset material from the web-like film.

The release agent prevents the first surface and the second surface of one of the panel members, which face each other, from being heat-sealed with each other during the heat sealing.

For example, the release agent may be medium ink.

A bag may be manufactured in which the release agent is applied to the outside but the release agent is not applied to the inside.

A side gusset material and a bottom gusset material may be used as the gusset material.
The bag-making method may comprise forming a side gusset portion of the bag with the side gusset material and forming a bottom gusset portion of the bag with the bottom gusset material.

According to another aspect, there is provided a bag making machine for making bags using two web-like panels and a gusset material as bag components. Each of the components is made of a single material.
The bag making machine
a conveying device for intermittently conveying the panel material in the longitudinal direction of the panel material;
a sealing device for sandwiching and heat-sealing the panel material and the gusset material laminated to each other with a heat-sealing member each time the panel material and the gusset material are intermittently conveyed;
a cross-cutting device disposed downstream of the sealing device for sequentially manufacturing bags by cross-cutting the panel member and the gusset member in the width direction of the panel member each time the panel member and the gusset member are conveyed intermittently;
At the time of heat-sealing by the sealing device, the release agent is interposed between the first and second surfaces facing each other in one of the components, so that the first and second surfaces are heat-sealed to each other. an applicator for applying the release agent to the film constituting the one component before the heat sealing so as to prevent the release agent from being peeled off;
The bag is manufactured sequentially such that the first side and the second side are outside the bag.

The bag making machine
A side gusset material supplying device may be provided for folding the film to form a side gusset material as the gusset material and supplying the side gusset material to the panel material.
The applicator may apply the release agent to the surface of the film that serves as the inner surface of the side gusset material.

The bag making machine
A forming device may be provided for folding the web-shaped film to form one of the panel members and a web-shaped bottom gusset member as the gusset member.
The applicator may apply the release agent to the web-like film such that the forming device forms the bottom gusset material coated with the release agent.

The conveying device may be configured to continuously convey the panel material in a section upstream of a section in which the panel material is intermittently conveyed.
The coating device may be provided in a section in which the panel material is continuously conveyed.

The coating device may apply the release agent to the web-shaped film in a section in which the side gusset material supply device continuously conveys the web-shaped film constituting the side gusset material.
The side gusset material supply device is provided downstream from the coating device, folds the web-shaped film in two on both sides with respect to the center line in the longitudinal direction of the film, and folds the side gusset material on the inner surface to which the release agent is applied. A folding unit may be provided for forming the gusset material.

FIG. 1 illustrates a bag. FIG. 2 is a cross-sectional view taken along line DD of FIG. 3A is a schematic plan view of the upstream portion of an exemplary bag making machine, and FIG. 3B is a front view thereof. 4A is a schematic plan view of the downstream portion of an exemplary bag making machine, and FIG. 4B is a front view thereof. FIG. 5 illustrates the release agent application pattern and some steps of the bag making process. FIG. 6 partially shows an exploded view of the side gusset material. Figures 7A and 7B illustrate the application of the release agent. FIG. 8 illustrates the application of the release agent. Figures 9A and 9B illustrate the application of the release agent. FIG. 10 illustrates heat sealing. FIG. 11 partially and schematically shows another exemplary bag making machine. FIG. 12 partially and schematically shows another exemplary bag making machine.

Embodiments will be described below with reference to the drawings.

The bag 1 in Fig. 1 is manufactured in the embodiment. The bag 1 includes body portions 10, 11 and gusset portions 12, 13 facing each other. The gusset portions 12 and 13 are folded in two. The gusset portions are a pair of side gusset portions 12 and a bottom gusset portion 13 .

The side gusset portions 12 are folded between the trunk portions 10 and 11 and extend along both side edges of the trunk portions 10 and 11 . One end portion of each side gusset portion 12 is folded between two layers of the side gusset portion 12 to form an auxiliary gusset portion 120 . The bottom gusset portion 13 is folded between the trunk portions 10 and 11 and positioned between the side gusset portions 12 (specifically, the auxiliary gusset portion 120) along one edge of the trunk portions 10 and 11. extended. The gussets 12, 13 allow the capacity of the bag 1 to be increased. The bottom gusset portion 13 provides the bag 1 with self-supporting properties.

The bag 1 further includes side seal portions 14 extending along both side edges of the body portions 10 and 11 and a bottom seal portion 15 extending along one end edge of the body portions 10 and 11 . The side gusset portion 12 is sealed to the body portions 10 and 11 at the side seal portion 14 . Further, the side gusset portion 12 (auxiliary gusset portion 120 ) is sealed to the bottom gusset portion 13 at the side seal portion 14 . The bottom gusset portion 13 is sealed to the body portions 10 and 11 at the bottom sealing portion 15 .

FIG. 2 is a schematic cross-sectional view taken along line DD in FIG. The mutually facing surfaces of the side gusset portions 12 are not sealed. The non-sealed areas are indicated by dashed lines and symbols R1, R2 and R3 in FIG. The mutually facing surfaces of the bottom gusset portion 13 are not sealed. This non-sealed area is indicated by a dashed line and reference R4. As a result, the gusset portions 12 and 13 exhibit the above functions without any problem. It should be noted that in FIG. 2, the sealing areas between different components 10-13 are indicated by solid lines and symbols R5-R10, respectively.

An exemplary bag-making machine and bag-making method for sequentially manufacturing the bags 1 will be described below.

3A and 3B schematically show the upstream portion of an exemplary bag making machine. A wide web-like film 2 is continuously unwound from a raw roll 2' at a constant speed. The film 2' is slit longitudinally through an accumulator 60 into two webs of film, i.e. two webs of panel material 20,21. The panel members 20 and 21 are then vertically separated from each other.

The panel members 20, 21 are conveyed by a conveying device in their longitudinal direction. Its transport direction is indicated by X1. The conveying device comprises a plurality of conveying roller pairs 61 , 62 and double dancers 63 . The transport roller pair 61, 62 is driven and controlled by, for example, a servomotor. The conveying device continuously conveys the panels 20 and 21 by a pair of conveying rollers 61 in the section upstream of the double dancer 63, and intermittently conveys the panels 20 and 21 by the pair of conveying rollers 62 in the section downstream of the double dancer 63. transport. The double dancer 63 appropriately switches continuous transport to intermittent transport.

The supply unit 64 of the side gusset material supply device 74 (FIG. 5) supplies the side gusset material 22 (FIG. 5) to the panel material 21 on the lower side. As shown in FIG. 5, the side gusset material 22 is folded in two on both sides with respect to the longitudinal center line 22c, and has a flat and substantially cylindrical shape. The supply unit 64 supplies the side gusset material 22 to the panel material 21 each time it is intermittently conveyed, arranges the side gusset material 22 on the panel material 21 in the width direction of the panel material 21, and seals the panel material 21 by ultrasonic or heat sealing. to temporarily hold. Application of the release agent to the side gusset material 22 will be described later.

Then, the webs 20, 21 are guided by the guide rollers 66 and overlapped with each other at the position of the guide rollers 66. As a result, the side gusset material 22 is sandwiched between the panel materials 20 and 21 .

A tacking device 67 then tacks the side gusset material 22 also to the upper panel material 20 in the form of ultrasonic or heat sealing.

Then, the forming device 68 guides the panel material 20 as the panel material 20, 21 is conveyed so that the panel material 20 is folded along the first folding line 200 (Fig. 5). One upper layer of side gusset material 22 is temporarily secured to panel material 20 . Therefore, when the panel material 20 is folded along the first fold line 200, the top layer of the side gusset material 22 is lifted at one end portion thereof. Accordingly, the side gusset material 22 is opened at one end portion to form a generally diamond-shaped opening surface 220' (FIG. 5).

As clearly shown in FIG. 5, the lower panel member 21 is wider than the upper panel member 20 . The forming device 68 guides the panel material 21 as the panel materials 20 and 21 are conveyed so that the panel material 21 is folded along the second folding line 210 and overlapped with the open surface 220'. to

Then, a sealing device 69 (hereinafter referred to as an opening face sealing device) seals the side gusset material 22 to the panel members 20 and 21 at the position of the opening face 220' and on the center line 22c of the side gusset material 22. heat seal.

Then, at a position downstream of the opening surface sealing device 69, the forming device 68 folds back the panel material 20 along the first folding line 200 as the panel material 20, 21 is conveyed, whereby the panel material 21 is also folded to the first folding line 200. Fold along the folding line 200 . A bottom gusset material 23 is formed by the panel material 21 and sandwiched between the two panel materials 20, 21 by folding the panel material 21 along the fold lines 200,210. That is, the panel material 21 and the bottom gusset material 23 are formed by one sheet of film. Further, by this folding, the opening surface 220' is also folded along the first folding line 200 to form the folded portion 220 (FIG. 5). The bottom gusset material 23 is sandwiched between the folded portions 220 at the position of the side gusset material 22 .

　Figures 4A and 4B schematically show the downstream part of the bag making machine. Then, a sealing device 71 (hereinafter referred to as a vertical sealing device) seals the bottom gusset material 23 to the panel materials 20, 21 along the outer edge of the bottom gusset material 23 in the longitudinal direction of the panel materials 20, 21 at each intermittent feeding. and heat seal. Thereby, a vertical seal portion (not shown) is formed.

Then, the sealing device 72 (hereinafter referred to as a horizontal sealing device) moves the side gusset material 22 to the panel members 20, 21 and the bottom gusset member 23 in the width direction of the panel members 20, 21 at each intermittent feeding, and the center line 22c of the panel members 20, 21. Heat-seal at the position. Thereby, a lateral seal portion (not shown) is formed.

Then, the cross-cutting device 73 cross-cuts the panel members 20, 21, the side gusset member 22, and the bottom gusset member 23 in the width direction of the panel members 20, 21 each time the panel members 20, 21 are fed intermittently. The crosscut location is the location of the lateral seal portion. Thereby, the bag 1 of FIG. 1 is manufactured from the bag components 20, 21, 22, 23 in sequence.

Specifically, the body portions 10, 11, the side gusset portion 12, the auxiliary gusset portion 120 thereof, the bottom gusset portion 13, the side seal portion 14, and the bottom seal portion 15 (see FIG. 1), the panel members 20, 21, the side The gusset material 22, its folded portion 220, the bottom gusset material 23, the horizontal seal portion, and the vertical seal portion are formed respectively. The bag making described above is substantially the same as in US Pat.

However, the components 20 to 23 of the bag are not laminated films as disclosed in Patent Documents 1 and 2, but films made of a single material such as polyethylene or polypropylene. Therefore, it is necessary to prevent the facing inner surfaces of the side gusset material 22 from being heat sealed together and the facing surfaces of the bottom gusset material 23 from being heat sealed together at each heat sealing step. Also, in the heat-sealing process by the opening surface sealing device 69, it is necessary to prevent heat sealing of the facing surfaces of the panel material 20 folded along the first folding line 200. FIG.

For this purpose, a release agent is used as in Patent Documents 3 and 4. The release agent is applied to either or both of the two surfaces that are not desired to be heat-sealed together such that upon heat-sealing, the two surfaces are aligned in the areas to which the release agent is applied. prevent them from being heat-sealed to each other. This principle itself is disclosed in Patent Documents 3 and 4.

As with Patent Documents 3 and 4, the release agent may be medium ink. Medium ink is substantially colorless and transparent ink, and is used for the purpose of adjusting density and imparting gloss, for example. Release agents other than medium ink may be used.

The application of the release agent to the side gusset material 22 is exemplified below. As shown in FIG. 5, a side gusset material feeder 74 is provided. Such a supply device 74 is disclosed in Patent Document 2 and the like.

In the supply device 74, the film 22' made of a single material that constitutes the side gusset material 22 is continuously fed out from the original film 22'' by a transport unit (not shown), passes through the dancer 76, and is transported by the transport unit. Transported intermittently. Its transport direction is indicated by the symbol Y1. Dancer 76 appropriately switches from continuous transport of film 22' to intermittent transport. The film 22' is then folded in half on both sides about its longitudinal centerline by the folding unit 77 to form the web-like side gusset material 22. As shown in FIG. Then, the web-like side gusset material 22 is turned by the turn bar 78 and cut by the supply unit 64 to a length corresponding to the intermittent conveying pitch P2, thereby forming the sheet side gusset material 22 . As described above, the sheet of side gusset material 22 is supplied to the panel material 21 by the supply unit 64 each time the panel material 20, 21 is intermittently conveyed.

The release agent 3 is applied in advance to a predetermined area on one surface of the film 22'. This face is the face that is the outside of the bag 1 . Then, the film 22' is folded in two on both sides with respect to its longitudinal centerline by the folding unit 77 to form the side gusset member 22 with the release agent 3 applied to a predetermined region of the inner surface. No release agent is applied to the opposite side of film 22'. Therefore, the release agent is not applied to the outer surface of the side gusset material 22 .

The release agent 3 is pre-applied to the film 22' in a pattern that is repeated with a pitch P2 (and hence the cut length). As a result, the side gusset material 22 of the sheet whose inner surface is coated with the release agent 3 in the pattern is sequentially formed.

FIG. 6 partially shows the release agent coated surface of the side gusset material 22 that has been developed. In the figure, the dashed-dotted line indicates a folding line.

The release agent 3 includes a first portion 30 extending over the entire length along the centerline 22c. Reference numeral 221 is a margin that is discarded during crosscutting. In other words, the cross-cut device 73 cuts the margin twice every time the sheet is conveyed intermittently. The film 22' is folded in half by the folding unit 77 so that the outer edges 222 of the film 22' are aligned with the border edges 2210 of the margin 221, respectively. The width of first portion 30 is greater than the width of margin 221 . The two-layered side gusset material 22 thus formed is arranged on the lower panel material 21 such that the layer containing both outer edges 222 is the lower layer and the layer containing the first portion 30 is the upper layer. be.

As a result, the lower layer including both outer edges 222 of the side gusset material 22 is temporarily fastened to the lower panel material 21 at the positions of both outer edges 222 . Since the upper layer of the side gusset material 22 is coated with the release agent 3 (first portion 30) on its lower surface (one inner surface), it is not temporarily fixed to the upper surface (other inner surface) of the lower layer of the side gusset material 22. , are temporarily fastened to the upper panel 20 . Therefore, since the upper layer is pulled up in conjunction with the panel material 20, the opening surface 220' can be formed.

Furthermore, the release agent 3 is also applied to either one or both of the regions T2 and T3 in FIG. For example, it is sufficient for the release agent 3 to include a second portion 31 (see FIG. 5) extending over the entire width of the film 22' so as to encompass the entire regions T1 and T2. In an embodiment, film 22' has a repeating pattern of first and second portions 30, 31 at pitch P2.

FIG. 7A is a top view partially showing the side gusset material 22 before the opening surface 220' is formed (the panel material 20, 21 is omitted). Region T3 faces the region of the central portion of side gusset material 22 prior to formation of open face 220'. Therefore, as is clear from FIGS. 6 and 7A, in the side gusset material 22, the release agent 3 is interposed between the region T3 and the central region.

FIG. 7B is a top view partially showing the side gusset material 22 formed with the opening surface 220' (the panel materials 20 and 21 are omitted). As is clear from FIGS. 6 and 7B, in the side gusset material 22 formed with the opening surface 220', the release agent 3 is interposed between the area T1 and the area of the side gusset material 22 facing this area. Regions T2 and T3 face each other when open surface 220' is formed. Therefore, in the side gusset member 22 having the open surface 220', the release agent 3 is interposed between the regions T2 and T3. The region T1 corresponds to the region R2 in FIG. 2, and the regions T2 and T3 correspond to the region R3 in FIG.

The application of the release agent to the panel material 20 is exemplified below. According to FIG. 5, a web 20 pre-applied with a release agent 4 and thus a film 2 (FIGS. 3A, 3B) is provided. The release agent 4 is applied to one surface of the panel material 20 in a predetermined pattern so as to be repeated at the intermittent conveying pitch P1 of the panel materials 20 and 21 . This face is the face that is the outside of the bag 1 . The release agent 4 is not applied to the opposite side of the web 20 . The pattern of the release agent 4 consists of a portion extending from one side edge 201 of the panel material 20 in the width direction of the panel material 20 for a predetermined length.

FIG. 8 is a top view partially showing the panel material 20 and the side gusset material 22 folded along the first folding line 200 (the panel material 21 is omitted). When the panel material 20 is folded along the first fold line 200 to form an open surface 220' in the side gusset material 22, two surfaces facing each other are formed in the panel material 20. As shown in FIG. The release agent 4 is interposed between these two surfaces of the web 20 at the location of the open surface 220'.

The application of the release agent to the bottom gusset material 23 is exemplified below. As shown in FIG. 5, in the embodiment, the bottom gusset material 23 is formed by bending the panel material 21 . A film (panel material) 21 pre-applied with a release agent 5 and thus a film 2 (FIGS. 3A, 3B) is used. The release agent 5 is applied in advance to one surface of the film 21 in a predetermined pattern so as to be repeated at a pitch P1. This face is the face that is the outside of the bag 1 . Release agent 5 is not applied to the opposite side of film 21 . In the embodiment, the pattern of the release agent 5 includes a first portion 50 extending from one side edge 211 of the film 21 in the width direction of the film 21 for a predetermined length, and a second portion extending in the longitudinal direction of the film 21 . 51, 52.

FIG. 9A is a top view partially showing the panel members 20, 21 and the side gusset members 22 after forming the opening surface 220'. FIG. 9B is a top view partially showing panel members 20, 21 and side gusset members 22 after forming folds 220 and bottom gusset members 23. FIG. As shown in FIG. 9A, the first portion 50 is in the center position of the opening surface 220' when the panel material 21 is folded along the second folding line 210 and overlaid on the opening surface 220'. Therefore, as shown in FIG. 9B, when the bottom gusset member 23 and the folded portion 220 are formed, the first portion 50 is interposed between the two surfaces of the bottom gusset member 23 facing each other at the position of the folded portion 220. there is The area where the first portion 50 is applied corresponds to area R4 in FIG.

The second portions 51 and 52 are formed along the second folding line 210 and one side edge 211 of the film 21, respectively. Therefore, when the bottom gusset material 23 is formed, the second parts 51 and 52 are interposed between the two surfaces of the bottom gusset material 23 facing each other, and the outer edges of the bottom gusset material 23 (the second folding line 210 and the one line) (corresponding to side edge 211). One of the two second parts 51, 52 may be omitted. This is because even if one side is omitted, the release agent 5 will be interposed between these two sides.

The release agents 3, 4, and 5 are applied in advance to areas where the above can be achieved.

As previously described, the supply unit 64 places the side gusset material 22 on the panel material 21 and temporarily secures the side gusset material 22 to the panel material 21 in the form of ultrasonic waves or heat sealing at a position on the centerline 22c. At this time, since the release agent 3 is interposed between the two inner surfaces of the side gusset material 22 at the position of the center line 22c, it prevents these inner surfaces from adhering to each other.

The same applies when the temporary fastening device 67 temporarily fastens the side gusset material 22 to the panel material 20 at the position on its center line 22c. That is, at this time, the release agent 3 prevents the two facing inner surfaces of the side gusset material 22 from adhering to each other. In this manner, the inner surfaces of the side gusset material 22 do not adhere to each other, thereby ensuring subsequent formation of the open surface 220'.

The opening face sealing device 69 uses a pair of heat sealing members 690 (FIG. 4B) to seal the panel members 20, 21 and the side gusset material 22, which are laminated together, in the opening face sealing range 691 (FIGS. 8 and 9A). Sandwiched, heated and pressurized. The face seal area 691 is along the diagonal of the face 220' extending across the width of the webs 20,21. As described above, the side gusset material 22 is thereby heat-sealed to the panel material 20, 21 at the position of the opening surface 220'.

As described above, the release agent 3 is interposed between the two inner surfaces of the side gusset material 22 facing each other within the open surface sealing range 691 . Thus, during open face heat sealing, the release agent 3 prevents these inner faces of the side gusset material 22 from being heat sealed together.

Furthermore, as described above, the release agent 4 is interposed between the two opposing surfaces of the panel material 20 folded in two within the open surface seal area 691 . Thus, during open face heat sealing, the release agent 4 prevents the faces of the web 20 from being heat sealed together.

The vertical sealing device 71 sandwiches the mutually laminated bottom gusset material 23 and panel materials 20, 21 with a pair of heat sealing members 710 (FIG. 4B) in a vertical sealing area 711 shown in FIG. pressure. A longitudinal seal area 711 is along the outer edges 210 , 211 of the bottom gusset material 23 . As previously described, the bottom gusset material 23 is thereby heat sealed to the webs 20,21 along its outer edges 210,211.

As described above, the release agent 5 is interposed between the two surfaces of the bottom gusset material 23 facing each other within the vertical seal area 711 . Therefore, during vertical heat-sealing, the release agent 5 prevents these surfaces of the bottom gusset material 23 from being heat-sealed together.

The lateral sealing device 72 is each of a plurality of pairs of heat sealing members 720 (FIG. 4B), and the panel members 20, 21, the side gusset material 22, and The bottom gusset material 23 is sandwiched and heated and pressurized. The lateral seal area 721 extends across the entire width of the panel members 20, 21 along the centerline 22c. As described above, the side gusset material 22 is thereby heat-sealed to the panel materials 20 and 21 and the bottom gusset material 23 . The areas heat-sealed at this time correspond to the seal areas R5-R10 in FIG. In addition, the plurality of pairs of heat seal members 720 are positioned at a pitch P1 (see FIG. 4B).

As described above, within the lateral sealing range 721, the release agent 3 is interposed between the two inner surfaces of the side gusset material 22 facing each other. Therefore, during lateral heat-sealing, the release agent 3 prevents these inner surfaces of the side gusset material 22 from being heat-sealed together. As described above, the release agent 5 is interposed between the two surfaces of the bottom gusset material 23 facing each other in the lateral seal area 721 . Thus, during lateral heat sealing, the release agent 5 prevents these surfaces of the bottom gusset material 23 from being heat sealed together. The regions that were not heat-sealed at this time correspond to the non-sealed regions R1 to R4 in FIG.

Naturally, in order to prevent heat sealing, in each heat sealing process, the heat sealing temperature is set lower than the melting point of the material of the release agent and higher than the material of the film constituting the constituent elements of the bag. Therefore, the release agent is selected from materials having a higher melting point than the film. The area to which the release agents 3, 4 and 5 are applied should be larger than the seal area. The application area may be sized to account for variations in transport of the films 20, 21, 22'.

As a result, it is possible to manufacture the bag 1 with the gusset portions 12 and 13 having the same configuration as in Patent Documents 1 and 2 even if the films 2 (20 and 21) and 22' made of a single material are used.

As described above, when heat-sealing different constituent elements of a bag, the inventor intervenes a release agent between the two surfaces of one constituent element that face each other and are outside the bag. By preventing the surfaces from being heat-sealed to each other, it has been found that gusseted bags can be manufactured sequentially even with a single material web and a single material gusset material.

Since it is only necessary to apply the release agent to the outer surface of the bag 1, it is possible to manufacture a bag in which no release agent is applied to the inside. For example, if a bag whose inside is coated with a release agent is to be filled with contents such as food, the release agent will be limited to those that meet predetermined standards such as the Food Sanitation Law. On the other hand, in the embodiment, since it is not necessary to apply the release agent to the inner surface of the bag, there is a high degree of freedom in selecting the release agent.

As described above, it is possible to sequentially manufacture bags that include a trunk and gusset made of environmentally friendly film made from a single material.

In the embodiment, films 2 (20, 21) and 22' already coated with a release agent are prepared. Alternatively, as in Patent Document 4, the bag making machine may be provided with an applicator for applying the release agent, and the application process may be performed in-line.

As shown in FIG. 11, the coating device 79 is arranged in the section where the feeding device 74 continuously conveys the film 22', and applies the release agent 3 to the film 22' in a predetermined pattern in this section. Thereafter, the film 22' is folded by a folding unit 77 provided downstream from the coating device 79 to form the side gusset material 22 with the release agent 3 applied on the inner surface.

As shown in FIG. 12, the coating device 81 may be arranged in a section where the conveying device continuously conveys the films 20 and 21, and apply the release agents 4 and 5 to the films 20 and 21 respectively in this section.

As in Patent Document 4, these coating devices 79 and 81 may be printers that print release ink (eg, medium ink) as a release agent, for example, by an inkjet method. Moreover, the coating devices 79 and 81 may apply the release agent by using a stamp, or may apply the release agent by pressing a roller impregnated with the release agent against the film.

A plurality of laminated films are cross-cut by the cross-cutting device 73, at which time the layers can be quasi-bonded. This is called blocking. Blocking can be avoided by adjusting the thickness of the applied release agent, or by applying the release agent to both layers facing each other.

The manufacturing of bags with gussets using a release agent can also be used to manufacture bags with gussets other than the above embodiment. The bottom gusset material 23 may be formed by folding a separate film separate from the panel material 21 and fed between the panel materials 20,21. The bottom gusset material 23 may be used as a top gusset material.

When the pattern is printed on the films 20, 21, 22', marks, such as registration marks, are printed on the edges of the films to improve the accuracy of the intermittent feed pitch of the films 20, 21, 22'. you can Specifically, a mark sensor may be arranged to detect the marks. By using the output of the mark sensor for film transport control, highly accurate transport is possible. Such marks may be used as reference standards for application positions when the release agents 3, 4, 5 are applied in predetermined patterns to the films 20, 21, 22', respectively. By using the marks and mark sensors, the positions of the printed patterns and the positions of the applied release agents 3, 4, 5 can be aligned with high accuracy. Films made of a single material tend to be more stretchable than laminated films, making alignment more difficult. Alignment techniques using marks and mark sensors enable highly accurate transport control and/or application position control.

2 Film 20 Panel material/Film 21 Panel material/Film 22' Film 22 Side gusset material 23 Bottom gusset material 3, 4, 5 Release agents 69, 71, 72 Sealing device 690, 710, 720 Heat sealing member 73 Cross cutting device 79 , 81 coating device

Claims (14)

1. 1. A bag-making method for manufacturing a bag using two web-like panel members and a gusset material as constituent elements of the bag, wherein the constituent elements are each made of a single material,
   Said bag-making method is:
   intermittently conveying the panel material in the longitudinal direction of the panel material by a conveying device;
   The panel material and the gusset material laminated to each other are heat-sealed by sandwiching them with heat-sealing members each time they are intermittently conveyed;
   After heat-sealing with the heat-sealing member, the panel material and the gusset material are cross-cut in the width direction of the panel material each time the panel material and the gusset material are conveyed intermittently to manufacture bags sequentially;
   During the heat-sealing, the release agent interposed between the first surface and the second surface prevents the first surface and the second surface facing each other in one component from being heat-sealed. wherein the release agent is pre-applied to the film constituting the one component, and the first surface and the second surface are surfaces that are outside the bag,
   A bag-making method characterized by:
2. Disposing a side gusset material as the gusset material between the panel members;
   When the panel material and the side gusset material are sandwiched between the heat-sealing members and heat-sealed in the width direction of the panel material, the release agent is applied to the first surface and the second surface of the side gusset material facing each other. prevent the faces from being heat-sealed together;
   The bag-making method according to claim 1.
3. applying the release agent to the first surface of the film; and
   After applying the release agent, the side gusset members are formed by folding the film in two on both sides with respect to the longitudinal center line of the film so that the inner surface of the side gusset members is formed by the first surface. to provide
   The bag-making method according to claim 2.
4. disposing a web-like bottom gusset material as the gusset material between the panel members;
   When the panel material and the bottom gusset material are sandwiched between the heat sealing members and heat-sealed in the longitudinal direction of the panel material, the release agent is applied to the first surface and the first surface of the bottom gusset material facing each other. prevent the two sides from being heat sealed together;
   The bag-making method according to claim 1.
5. applying the release agent to the web-like film forming one of the panel members and the bottom gusset member;
   folding the web-like film to form the one panel material and the release agent-coated bottom gusset material from the web-like film;
   The bag-making method according to claim 4.
6. The release agent prevents the first surface and the second surface of one of the panel members, which face each other, from being heat-sealed with each other during the heat sealing.
   The bag-making method according to claim 1.
7. The release agent is medium ink,
   The bag-making method according to any one of claims 1 to 6.
8. A bag is produced in which the release agent is applied to the outside but the release agent is not applied to the inside.
   The bag-making method according to any one of claims 1 to 7.
9. A side gusset material and a bottom gusset material are used as the gusset material,
   said side gusset material forming a side gusset portion of said bag and said bottom gusset material forming a bottom gusset portion of said bag;
   The bag-making method according to any one of claims 1 to 8.
10. 1. A bag-making machine for manufacturing a bag using two web-shaped panel members and a gusset material as constituent elements of the bag, wherein the constituent elements are each made of a single material,
    The bag making machine
    a conveying device for intermittently conveying the panel material in the longitudinal direction of the panel material;
    a sealing device for sandwiching and heat-sealing the panel material and the gusset material laminated to each other with a heat-sealing member each time the panel material and the gusset material are intermittently conveyed;
    a cross-cutting device disposed downstream of the sealing device for sequentially manufacturing bags by cross-cutting the panel member and the gusset member in the width direction of the panel member each time the panel member and the gusset member are conveyed intermittently;
    At the time of heat-sealing by the sealing device, the release agent is interposed between the first and second surfaces facing each other in one of the components, so that the first and second surfaces are heat-sealed to each other. an applicator for applying the release agent to the film constituting the one component before the heat sealing so as to prevent the release agent from being peeled off;
    sequentially manufacturing the bag such that the first side and the second side are outside the bag;
    A bag making machine characterized by:
11. a side gusset material supply device that folds the film to form a side gusset material as the gusset material and supplies the side gusset material to the panel material,
    The coating device applies the release agent to the surface of the film, which is the inner surface of the side gusset material.
    The bag making machine according to claim 10.
12. a forming device for folding the web-shaped film to form one of the panel members and a web-shaped bottom gusset member as the gusset member;
    The coating device applies the release agent to the web-like film such that the forming device forms the bottom gusset material coated with the release agent.
    The bag making machine according to claim 10.
13. The conveying device is configured to continuously convey the panel material in a section upstream of a section in which the panel material is intermittently conveyed,
    The coating device is provided in a section in which the panel material is continuously conveyed,
    The bag making machine according to claim 10.
14. The coating device applies the release agent to the web-shaped film in a section in which the side gusset material supply device continuously conveys the web-shaped film constituting the side gusset material,
    The side gusset material supply device includes:
    a folding unit provided downstream from the coating device for folding the web-shaped film in two on both sides with respect to the center line in the longitudinal direction of the film to form the side gusset material having the inner surface coated with the release agent; prepare
    The bag making machine according to claim 11.

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