Bag-making and filling method

Abstract

To provide a bag making and filling method of packaging bags that makes it easy to inflate and get the bags taut.SOLUTION: The bag making and filling method includes: a filling step; a sandwiching step; a transverse sealing step; and a cutting step. In the filling step, a content is filled into a tube equipped with a lower transverse sealing section with the lower side of the resin film closed, and, in the sandwiching step, a pair of shutter members sandwiches an upper part of the tube and changes a relative position between the shutter members and the tube in a vertical direction to make a portion containing the content, of the tube taut. In the transverse sealing step, transverse-sealing is performed on the tube at a position higher than a portion filled with the content, thereby, a transverse seal portion is formed. In the cutting step, the transverse seal portion is cut and divided into upper and lower portions, thereby, an upper transverse seal portion of downstream packaging bag and a lower transverse seal portion of upstream tube are formed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a packaging bag and a bag fill method. [Background technology]

[0002] Patent document 1 discloses a method for making and filling packaging bags that can give a tubular film the tension necessary to protect the contents without performing a heating process that could deteriorate the contents. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-291907 A Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, in the case of packaging bags manufactured using a laminate film having a shape as described in Reference 1, when the packaging bag is given tension, the packaging bag is less likely to expand near the horizontal seal portion, making it difficult to give the bag tension, leaving room for improvement.

[0005] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a bag making and filling method for a packaging bag that is easy to expand and to have tension. [Means for solving the problem]

[0006] According to the present invention, there is provided a bag making and filling method comprising a filling step, a sandwiching step, a lateral sealing step, and a cutting step, in which in the filling step, a cylindrical body having a lower lateral seal portion that closes the lower side of a resin film is filled with contents, in the sandwiching step, a pair of shutter members sandwich the upper part of the cylindrical body and change the relative position of the shutter members and the cylindrical body in the vertical direction to give tension to the part of the cylindrical body that contains the contents, and in the lateral sealing step, a lateral seal portion is formed by horizontally sealing the cylindrical body at a position higher than the part filled with the contents, The cutting process forms an upper horizontal seal portion for a downstream packaging bag and a lower horizontal seal portion for a cylinder on the upstream side by cutting the horizontal seal portion and dividing it into an upper and lower portion, and left and right curved portions that convex outward are provided at both ends of the inner edges of the upper horizontal seal portion and the lower horizontal seal portion, wherein, when the left-right length of the upper horizontal seal portion and the lower horizontal seal portion is Ws and the left-right lengths of the left curved portion and the right curved portion are Wl and Wr, respectively, Wr / Ws and Wl / Ws are 0.1 to 0.4, and when the radii of curvature of the left curved portion and the right curved portion are Rl and Rr, respectively, Rl and Rr are 35 to 60 mm.

[0007] By adopting such a configuration, it is possible to manufacture a packaging bag that is easy to expand and has tension. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a plan view of the packaging bag 1 with no contents inside. [Diagram 2] FIG. 1 is a perspective view of a packaging bag 1 with contents inside. [Diagram 3] FIG. 2 is a layer structure diagram of film 2. [Figure 4] FIG. 1 is a configuration diagram of a bag making and filling machine 100. [Diagram 5] 1 is an enlarged view of the vicinity of a transverse sealing machine 116 of a bag making and filling machine 100, showing a state in which a transverse seal portion 11 is being formed by the transverse sealing machine 116. FIG. [Figure 6]5, the state after the horizontal sealing machine 116 is opened and the horizontal sealing unit 11 moves to the position of the press / cutter 118 is shown. [Figure 7] 6, shows a state in which the horizontal seal portion 11 is being clamped by the press / cutter 118. [Figure 8] 7, shows a state after the press / cutter 118 and the ironing rolls 115 are opened. [Figure 9] 8, shows the state after the contents W are further added and the squeezing rolls 115 are closed. [Figure 10] 9, the state after the contact portion 3a has moved to the position of the shutter member 123 is shown. [Figure 11] 10, the shutter member 123 sandwiches the cylindrical body 3 and moves vertically downward. [Figure 12] 11, the state in which the horizontal seal portion 11 is being formed by the horizontal sealing machine 116 is shown. [Figure 13] 12, shows a state in which the horizontal seal portion 11 is being clamped by the press / cutter 118. [Figure 14] 13, the state after the press / cutter 118 and the ironing rolls 115 are opened. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, embodiments of the present invention will be described. Various features shown in the following embodiments can be combined with each other. Also, each feature can be an invention independently.

[0010] 1. Packaging bag 1 As shown in Figures 1 to 3, a packaging bag 1 according to one embodiment of the present invention comprises a cylinder 3 formed by forming a vertical seal portion 7 on a film 2, an upper horizontal seal portion 4, and a lower horizontal seal portion 5. The packaging bag 1 is usually filled with contents, but for convenience, Figure 1 shows the packaging bag 1 in a state where no contents are filled. Examples of contents include viscous foods such as flower paste, jam, and bean paste.

[0011] 1 will be referred to as the top, bottom, left and right of the packaging bag 1 in the following description. Specifically, the axial direction of the cylinder 3 is the top and bottom direction. The left and right sides when the vertical seal portion 7 is disposed on the front side are the left and right sides of the packaging bag 1. The surface on the vertical seal portion 7 side is referred to as the front side, and the opposite surface is referred to as the back side.

[0012] The length of the packaging bag 1 in the left-right direction is, for example, 140 to 240 mm, and preferably 160 to 220 mm. This length is, for example, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, and 240, and may be within a range between any two of the numerical values ​​exemplified here. If this value is too small, the contents may adhere to the inner surface of the packaging bag 1 during bag making and filling, making it difficult to fill. This problem is prominent when the viscosity of the contents is high. The value of [vertical length of packaging bag 1 / left-right length of packaging bag 1] is, for example, 1.5 to 5, and preferably 2 to 4. This value is, for example, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, and 5, and may be within a range between any two of the numerical values ​​exemplified here.

[0013] The cylinder 3 can be formed by bending the film 2 into a cylindrical shape and heat sealing both ends of the film 2 in an overlapping state. A vertical seal portion 7 is formed by the heat sealing.

[0014] The upper horizontal seal portion 4 and the lower horizontal seal portion 5 are provided so as to close the upper and lower sides, respectively, of the cylindrical body 3. The horizontal seal portions 4, 5 are preferably formed along the upper and lower ends, respectively, of the cylindrical body 3. The horizontal seal portions 4, 5 are preferably formed so as to be perpendicular to the vertical seal portion 7. The horizontal seal portions 4, 5 can each be formed by heat-sealing the cylindrical body 3.

[0015] In one example, the horizontal seal portions 4, 5 are composed of a plurality of linear seal portions 4a, 5a (areas indicated by dotted lines in FIG. 1) aligned in the vertical direction. Each linear seal portion 4a, 5a is provided so as to extend in the left-right direction of the horizontal seal portions 4, 5. The linear seal portions 4a, 5a are preferably arranged in parallel. The linear seal portions 4a, 5a are preferably provided at a pitch of 2 to 5 mm. Specifically, this pitch is, for example, 2, 2.5, 3, 3.5, 4, 4.5, or 5 mm, and may be within a range between any two of the numerical values ​​exemplified here.

[0016] A heat-shrinkable film (so-called shrink film) is used as the film 2. The heat-shrinkable film is a resin film that is provided with heat shrinkability by, for example, performing a stretching process (uniaxial stretching or biaxial stretching).

[0017] In areas of the packaging bag 1 near the horizontal seal portions 4, 5, the packaging bag 1 is less likely to expand, causing the packaging bag 1 to assume a flat shape, which hinders rolling transport of the packaging bag 1. This tendency is particularly noticeable when the inner edges of the horizontal seal portions 4, 5 are not provided with curved portions that convex outward at both ends, or when curved portions are provided but their length in the left-right direction is short.

[0018] In this embodiment, the left curved portions 4l, 5l and the right curved portions 4r, 5r are provided at both ends of the inner edge of the horizontal seal portions 4, 5, which are convex toward the outside. In addition, if the horizontal seal portions 4, 5 have a left-right length Ws and the left-right lengths of the left curved portions 4l, 5l and the right curved portions 4r, 5r Wl, Wr, Wr / Ws and Wl / Ws are set to 0.1 to 0.4, respectively. By forming such curved portions, as shown in FIG. 2, the packaging bag 1 is easily expanded even in the vicinity of the horizontal seal portions 4, 5, and the outer shape becomes approximately cylindrical, so that the rolling and conveying of the packaging bag 1 becomes smooth. It is preferable that Wr and Wl are the same, but they may be different from each other. Specifically, Wr / Ws and Wl / Ws are, for example, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, and 0.4, and may be within a range between any two of the numerical values ​​exemplified here. Ws is the same as the length of the packaging bag 1 in the left-right direction. Wl and Wr are, for example, 10 to 100 mm, and preferably 20 to 50 mm. Specifically, Wl and Wr are, for example, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 mm, and may be within a range between any two of the numerical values ​​exemplified here.

[0019] In addition, the left curved portion 4l, 5l and the right curved portion 4r, 5r are preferably arc-shaped, and when the radii of curvature are Rl, Rr, Rl / Ws and Rr / Ws are preferably 0.1 to 0.4. Specifically, Rl / Ws and Rr / Ws are, for example, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, and may be within a range between any two of the numerical values ​​exemplified here. Rl, Rr are, for example, 20 to 60 mm, and preferably 30 to 50 mm. Specifically, Rl, Rr are, for example, 20, 25, 30, 35, 40, 45, 50, 55, 60 mm, and may be within a range between any two of the numerical values ​​exemplified here.

[0020] As shown in FIG. 3, the film 2 is preferably a laminated film having a base layer 2a and a sealant layer 2b, and more preferably has an adhesive layer 2c between the base layer 2a and the sealant layer 2b.

[0021] The base material layer 2a is disposed so as to be exposed on the outer surface of the packaging bag 1, and the sealant layer 2b is disposed so as to be exposed on the inner surface of the packaging bag 1. The sealant layers 2b are heat-sealed to each other to form the vertical seal portion 7 and the horizontal seal portions 4 and 5.

[0022] The base layer 2a is made of a material having excellent strength and high impact resistance. For example, heat-shrinkable polyamide, polyolefin, polyethylene, etc. are used as the base layer 2a. The adhesive layer 2c is a layer for bonding the base layer 2a and the sealant layer 2b so that they are laminated together, and for example, polyethylene, etc. are used as the adhesive layer 2c.

[0023] The polyamide of the base layer 2a preferably contains an aromatic polyamide. In this case, the base layer 2a has linear cutting properties in the MD direction and has excellent barrier properties. There are no particular limitations on the aromatic polyamide, but it is possible to use a resin containing 70 mol % or more of polyamide structural units composed of xylylenediamine and an α,ω-aliphatic dicarboxylic acid having 6 to 12 carbon atoms in the molecular chain. Specific examples include homopolymers such as polymetaxylylene adipamide, polymetaxylylene pimelamide, polymetaxylylene azelamide, polyparaxylylene azelamide, and polyparaxylylene decanamide, and copolymers such as metaxylylene / paraxylylene adipamide copolymer, metaxylylene / paraxylylene pimelamide copolymer, metaxylylene / paraxylylene azelamide copolymer, and metaxylylene / paraxylylene sepacamide copolymer, with polymetaxylylene adipamide (hereinafter referred to as "MXD6") being preferred as it has excellent basic properties such as strength and gas barrier properties, and is relatively easily available industrially.

[0024] The sealant layer 2b can be formed of a resin having excellent heat sealability. For example, the sealant layer 2b can be formed of linear low-density polyethylene. The film constituting the sealant layer 2b is preferably one having linear cutability in the MD direction.

[0025] Further, it is preferable that at least one of the base material layer 2a and the sealant layer 2b has linear cuttability. The thickness of the sealant layer 2b is preferably at least twice the thickness of the base material layer 2a and preferably at least half the thickness of the entire film 2.

[0026] The film 2 can be formed by laminating a base material layer 2a with a thickness of 10 μm to 20 μm, for example 15 μm, an adhesive layer 2c with a thickness of 10 μm to 30 μm, for example 20 μm, and a sealant layer 2b with a thickness of 30 μm to 50 μm, for example 40 μm. As the film 2, it usually has a thickness of 50 μm to 100 μm.

[0027] Also, the base material layer 2a and the sealant layer 2b are adhered to each other so as to be laminated by the adhesive layer 2c. For example, polyethylene can be used as the adhesive layer 2c, and the base material layer 2a and the sealant layer 2b can be adhered to each other using the extrusion lamination method. Also, materials other than polyethylene can be used as the adhesive layer 2c, and the base material layer 2a and the sealant layer 2b can be adhered to each other using the dry lamination method. Alternatively, fusion without using the adhesive layer 2c can also be utilized. In this way, the film 2 formed from the base material layer 2a, the adhesive layer 2c, and the sealant layer 2b has high strength, impact resistance, sealing performance, airtightness, etc.

[0028] 2. Bag-making and filling method Next, with reference to FIGS. 4 to 14, a bag-making and filling method using the film 2 will be described. This method can be implemented using a vertical bag-making and filling machine 100.

[0029] <S1: Film bending process> As shown in FIG. 4, the film 2 fed out from the roll-shaped web F is guided to the former 112 via a plurality of pay-off rolls 120 and 121. A sensor 119 is disposed in the path from the roll-shaped web F to the former 112, and detects the registration marks printed at regular intervals in the length direction on the film 2, so that the film 2 of a certain length can be sent out at regular time intervals on the track of the bag-making and filling machine 100. While passing through the former 112, the film 2 is curved into a cylindrical shape, and both side edges of the curved tip overlap each other. An overlapping portion is formed at the overlapping part.

[0030] Note that, a printing process for printing on the film 2 may be provided at a position in front of the former 112. This printing is preferably performed in an area that will become the front surface (the surface on the side of the longitudinal seal portion 7) of the packaging bag 1. In this case, when conveying the packaging bag 1 that has fallen onto the conveyor 130 in the cutting process described later with the longitudinal seal portion 7 on the upper side, it is possible to confirm whether the printing is properly performed.

[0031] <S2: Longitudinal sealing process> Next, the overlapping portion of the film 2 is heat-sealed by the longitudinal sealer 113 to form the longitudinal seal portion 7. The longitudinal sealer 113 includes a pair of seal rolls, and in accordance with the timing of the film 2 moving at regular time intervals, while sandwiching the overlapping portion of the film 2 with the pair of seal rolls, the pair of seal rolls are rotated in opposite directions to each other to perform heat-sealing while feeding out the film 2. By forming the longitudinal seal portion 7 on the film 2, the cylindrical body 3 is formed. Then, by rotating the feed roll 114, the cylindrical body 3 is moved downstream by a predetermined length.

[0032] <S3: Transverse sealing process> As shown in FIG. 5, a predetermined position of the cylindrical body 3 is heat-sealed by the horizontal sealing machine 116 to form a horizontal seal portion 11. The horizontal seal portion 11 is configured by connecting the upper horizontal seal portion 4 of the downstream packaging bag 1 and the lower horizontal seal portion 5 of the upstream cylindrical body 3, and is divided vertically in the cutting process described later. The horizontal sealing machine 116 includes a pair of seal bars 116a, and performs heat sealing by clamping the predetermined position with the pair of seal bars 116a for a predetermined time.

[0033] In one example, the seal bar 116a has a shape in which ridges and grooves extending in the left-right direction of FIG. 1 are alternately arranged in the vertical direction. In this case, linear seal portions (portions indicated by dotted lines in FIG. 1) 4a and 5a are formed at the portions where the ridges are pressed.

[0034] <S4: Cutting Process> Next, as shown in FIG. 6, by further rotating the feed roll 114, the horizontal seal portion 11 is moved to the position of the press-cutter 118. The press-cutter 118 includes a pair of bars 118a.

[0035] Next, as shown in FIG. 7, the press-cutter 118 is closed to clamp and cool the horizontal seal portion 11, and the horizontal seal portion 11 is cut with a cutter blade (not shown) to be divided vertically, thereby forming the upper horizontal seal portion of the downstream cut piece U and the lower horizontal seal portion 5 of the upstream cylindrical body 3. When the horizontal seal portion 11 is cut, the cut piece U falls onto the conveyor 130.

[0036] <S5: Filling Process> Next, as shown in FIG. 8, when the squeezing roll 115 is opened, the content W that was introduced from the hopper 111 in the previous process and accumulated above the squeezing roll 115 falls to the lower side of the squeezing roll 115. Since the lower horizontal seal portion 5 is formed on the cylindrical body 3, the fallen content W is filled into the cylindrical body 3. A pair of shutter members 123 are arranged around the cylindrical body 3. The shutter member 123 is configured to be movable in the horizontal and vertical directions.

[0037] The content W is further put into the cylinder body 3. When the content W in the cylinder body 3 reaches the position of the sensor 122, as shown in FIG. 9, by closing the squeezing roll 115, the content W is divided into an upper part and a lower part of the squeezing roll 115. The content in the lower part of the squeezing roll 115 is the content for one bag of the packaging bag 1. Also, by closing the squeezing roll 115, an adhering part 3a is formed on the cylinder body 3, and a bag part 3b is formed, which is the part where the content is accommodated between the adhering part 3a and the lower horizontal sealing part 5.

[0038] <S6: Feeding process> Next, with the squeezing roll 115 closed, by rotating the feeding roll 114, as shown in FIG. 10, the adhering part 3a is moved to the position of the shutter member 123.

[0039] <S7: Clamping process> Next, as shown in FIG. 11, the shutter member 123 is moved horizontally to clamp the adhering part 3a above the cylinder body, and further, by moving the shutter member 123 vertically downward (refer to the arrow in FIG. 11), the bag part 3b can be given tension. Here, it is preferable that the shutter member 123 is moved below the horizontal sealing machine 116. By doing so, it becomes possible to perform the horizontal sealing while maintaining the tension given to the bag part 3b.

[0040] After that, as shown in FIG. 12, by performing the horizontal sealing process (S3) while maintaining the shutter member 123 above the bag part 3b, at a position (adhering part 3a) higher than the part (bag part 3b) filled with the content W, the horizontal sealing part 11 can be formed while giving tension to the bag part 3b, and the packaging bag 1 is formed.

[0041] Then, as shown in FIG. 13, the shutter member 123 is returned to its original position, and the subsequent cutting process (S4) is performed. As a result, as shown in FIG. 14, the packaging bag 1 falls onto the conveyor 130.

[0042] In this manner, by repeating the steps S3 to S7, it is possible to continuously produce packaging bags 1 filled with the contents W. Note that, in the production of the packaging bag 1 in this embodiment, no heat treatment step is performed.

[0043] As described above, in the bag making and filling method of the present embodiment, the above-mentioned sandwiching process is performed on the cylinder 3 made of heat shrinkable film, thereby imparting the necessary tension to the packaging bag 1. In this way, it is possible to manufacture a packaging bag that is stronger and less prone to pinholes than a non-heat shrinkable laminate film.

[0044] 3. Other embodiments In the above embodiment, the shutter member 123 is moved vertically downward, but the present invention is not limited to this. For example, the cylinder body 3 may be tensioned by moving the cylinder body 3 vertically upward in a state where the shutter member 123 sandwiches the cylinder body 3. In this way, by changing the relative position in the vertical direction between the shutter member 123 sandwiching the cylinder body 3 and the cylinder body 3, it is possible to obtain the same effect as the above embodiment. [Explanation of symbols]

[0045] 1: Packaging bag 2: Film 2a: Base material layer 2b: sealant layer 2c: Adhesive layer 3: Cylindrical body 3a: Contact area 3b: Bag part 4: Horizontal seal section 4a: Linear seal part 4l: Left curved part 4r: Right curved part 5: Horizontal seal section 5a: Linear seal part 5l: Left curved part 5r: Right curved part 7: Vertical seal part 11: Horizontal seal section 100: Bag making and filling machine 111: Hopper 112:Forma 113: Vertical sealing machine 114: Feed roll 115: Roll 116: Horizontal sealing machine 116a: Seal bar 118: Press and cutter 118a: Bar 119: Sensor 120: Payout roll 121: Payout roll 122: Sensor 123: Shutter parts 130: Conveyor

Claims

[Claim 1] A bag making and filling method comprising a filling step, a sandwiching step, a lateral sealing step, and a cutting step, In the filling step, a content is filled into a cylindrical body having a lower transverse seal portion in which a lower side of a resin film is sealed, In the clamping step, a pair of shutter members clamps the upper part of the cylindrical body, and a relative position between the shutter members and the cylindrical body in a vertical direction is changed to give tension to a portion of the cylindrical body that contains the contents, In the transverse sealing step, a transverse seal portion is formed by transversely sealing the cylindrical body at a position higher than the portion where the content is filled, In the cutting step, the transverse seal portion is cut and divided into upper and lower portions to form an upper transverse seal portion for a downstream packaging bag and a lower transverse seal portion for a downstream cylindrical body, a left curved portion and a right curved portion that are convex outward are provided at both ends of the inner edges of the upper horizontal seal portion and the lower horizontal seal portion, the left and right lengths of the upper horizontal seal portion and the lower horizontal seal portion being Ws and Wl and Wr, respectively, and Wr / Ws and Wl / Ws are 0.1 to 0.4, The method according to the present invention, wherein the radii of curvature of the left curved portion and the right curved portion are Rl and Rr, respectively, and Rl and Rr are 35 to 60 mm.

Images