JP2000117854A - Production of bag body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bag making method having an angularly circular cut end part and an unheat-sealed part for packing in a bag body in which the three sides of a laminated film having a heat sealant layer are heat-sealed, and the residual side unheat-sealed part is made to be a packing part. SOLUTION: A separation part is formed by a spacer 1 in a slit part 3 formed between the adjoining films of longitudinal heat seal parts 11, 12 of a bag making machine for producing a tree-side heat-sealed bag body 50 from a laminated film having at least a heat sealant layer, an angular circle trimming die is inserted into the separation part, angular circle trimming parts 20, 21, 22 are formed, and the cutting of a transverse seal part 16 is done in two places before and behind an angularly circular middle part to form the bag body having arc-shaped cut end parts 41A, 42A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In a bag which is used with its four ends sealed by heat sealing, the corners of the bag are rounded, and the ends are not heat-sealed for filling (hereinafter the heat seal is simply referred to as HS). The same applies to a non-HS part and an HS part). This is a bag making method in which in-line processing can be performed with high accuracy on a bag body having a multi-row bag making machine.

[0002]

2. Description of the Related Art A rectangular bag (hereinafter, referred to as a "bag") having a multi-layer plastic film as a base material and having four ends sealed with HS.
In this specification, it is described as a four-sided HS bag. ) Is used for devices requiring high sealing accuracy. In order to maintain the shape of the packaging bag after filling the contents such as a liquid material, a rigid rigid stretched film or the like is used as a component of the laminated film. In addition, the corners of the four-sided HS bag having a right-angled shape become sharp protrusions, which may pierce another bag to make a hole or, in an extreme case, injure the human body. In order to prevent such an accident, a so-called (corner round method) in which the corner of the bag body is cut off in a round shape has been adopted.

[0003] In order to provide a rounded corner in the bag, a four-way H having an unHS portion (which is an opening for filling the contents) is used.
S bag (3-way HS with open part (non-HS part) when not filled)
Bags) are manufactured by a bag making machine, then stacked and bundled in a plurality of bags and cut off with a round blade, or an in-line square round punching system for punching out with a bag making machine.

In the offline guillotine method, dozens to hundreds of finished bags are aligned, bound, stacked, set in a punching machine, and cut off with a round blade by driving an air cylinder. . At this time, the pouch can be pulled out of two of the four corners at one time. However, when the bag is large, the laminated film is thick,
It is difficult to bind a large number of bags because of bending, and cutting off a large number of thick films is not straight because the blade loses and the rounded corners are not formed roundly. There was a problem that burrs may adhere to the body. Therefore, in a separate process, chips were cut off by using scissors, and the bag making speed was reduced to remove chips. For this reason, there is a large loss in terms of time and personnel, and there is a major problem not only in quality but also in efficiency.

[0005] The bag making in-line rounded corner method is an excellent method in that the bag making efficiency and the shape of the rounded corner are constant. However, on the bag making machine, in both the horizontal direction and the vertical direction, the slits between the adjacent bag bodies (the processing for cutting in the vertical direction is referred to as slit) and the cutting (the processing for cutting in the horizontal direction is referred to as cutting). It is difficult to accurately capture the position and stably perform the work. (In the present specification, the processing direction or the production direction of the film is described as vertical, and the direction crossing the vertical is described as horizontal.) If the positions of the slits and the cutting can be captured and controlled ideally accurately, For example, as shown in FIG. 2, a rounded cutting blade 26 having a sharp tip is used, and a slit portion 3 is provided so that the position of the slit passes through the front end in the flow direction. If punching is performed at the part, the step can be made zero as much as possible. If the slit position and the cutting position can be manufactured accurately and continuously, the ideal rounded shape shown in FIG. 3 can be formed. However, there is a problem that a step 51 is generated as shown in FIG. 4 because the meandering of the film and the running accuracy of the bag making machine are not always stable. In addition to the appearance problem, there is also a problem that an operator who scratches and packs the bags is scratched. Therefore, the shape of the rounding die is provided with a straight portion at the tip end as shown in the rounding die 25 of FIG. 5, and the cutting and slit are cut at the straight portion at the tip as shown in FIG. There has been proposed a method in which there is no variation in appearance assuming that the step 5 is generated from the beginning, and a rounded portion is provided in which it is difficult to form a sharp convex portion.
Then, cutting was performed twice at the cross cutting positions 17 and 18 before and after the horizontal punching portion as shown in FIG. 7, but the bag making speed was reduced and the film was likely to meander, and the cutting position was changed. There was a problem that the fluctuation was large.

[0006]

The present invention provides a laminated film having an HS layer, wherein three sides of the laminated film are subjected to HS and the remaining non-HS part is filled with a rounded corner at the corner when the bag is made. An object of the present invention is to provide a method of manufacturing a bag having a rounded corner without a step in a bag making machine for a bag having an unHS portion for filling at an end portion.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a laminated film having at least an HS layer, wherein the three-sided end of the bag is HS-rounded, and the end of the bag is filled with an unfilled bag. In a bag making machine for manufacturing a bag having an HS part,
A slit is made at the center of the film of the bag body adjacent to the vertical HS portion, a rounding die is inserted into a separation portion formed by inserting a spacer, and a rounding portion is punched out to form a rounding portion, Furthermore, this is a method of manufacturing a bag body in which a horizontal HS portion is cut at two places before and after a rounded portion.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A bag manufacturing method of the present invention is shown in FIG.
The layers are folded in half so as to be in contact with each other so as to form a vertical HS portion 11 and a horizontal HS portion 16, trimming both ends, and a slit portion 3 for inserting a spacer are provided. Furthermore, the spacer 1 is inserted into the slit portion 3, and a rounded-off die is provided with a rounded-off portion 20 at the center and rounded-off portions 21 and 22 at both ends. Thereafter, the cutting position 17 is set using the cutting blade 79.
And 18 are cut to form cutting edges 41 and 42, and cutting corners 41A and 42A, thereby forming a three-way HS.
The bag 50 is created. Also, the description above
The slit portion 3 is described in a state where the HS is not subjected to HS, and the slit portion 3 is formed so that the non-HS portion of the formed bag is provided in the vertical direction. Although not particularly shown, the manufacturing method of the present invention inserts a spacer after HS in the slit portion 3 in FIG. 1 and inserts a rounded corner in a non-HS portion between the horizontal HS portion 16 and the next horizontal HS portion 16. By providing a punched portion and cutting as described above, it is possible to form a bag body provided with a non-HS portion in the lateral direction.

The laminated film including the HS layer is composed of at least the HS layer and a film having barrier properties and rigidity. The HS layer is made of a thermoplastic resin such as ethylene-vinyl acetate copolymer, polyethylene, polypropylene, polyamide or polyester, and the rigid base film is made of a stretched or non-stretched film such as polypropylene, polyamide or polyester. . The barrier layer provided as desired includes water vapor,
An aluminum foil having a barrier property against oxygen, carbon dioxide, light, etc., a film of an ethylene / vinyl alcohol copolymer or polyvinyl alcohol, or a biaxially stretched film provided with aluminum or silicon oxide deposited thereon is used.

The method of forming the laminated film includes dry lamination, non-solar lamination, sandwich lamination using a hot-melt resin as an adhesive resin, and extrusion of a hot-melt resin, which are performed by applying a usual curable adhesive to a base film. It can be formed by a usual processing method such as coating.

The side forming the inner and outer surfaces of the laminated film, that is, the surface that comes into contact with the bag making machine, is made by adding a lubricant to the resin or spraying a very small amount of fine powder to make it slippery. It is preferred that the running of the laminated film be facilitated to prevent film meandering.

As long as the bag making machine has an HS unit in a normal heat, pressure and cooling process, the shape of the HS bar, the heating method and the cooling method are not particularly limited. For example, the shape of the HS bar can be arbitrarily selected from a flat bar, a plurality of lines such as three lines, a grid, and the like. Also, a rotary roll can be used in the vertical direction. And H
Forming the side of the S portion in contact with the filler at 0.3 to 2 R is also preferable from the viewpoint of preventing fusing of the HS end.

The heat source for heating can be arbitrarily selected from electric heat using a nichrome wire or the like, high frequency, ultrasonic waves, heated steam, heated oil, etc. However, electric heat is advantageously used because of its cost.
The pressurizing method is selected from pneumatic, hydraulic, spring, and rotating rolls. Normally, an air pressure for easily adjusting the pressing force or a spring having a stable pressure is used, but is not particularly limited. The compression bonding of the film is performed by inserting the film between a hard metal and elastic rubber.

The HS section is stabilized by heating and pressurizing (cooling). Water is usually used for cooling in consideration of cost and cooling efficiency. However, air cooling or a heat medium such as oil is used. You can also. Impulse sealing or the like in which HS is performed by applying current and cooling with water under pressure is also one of the preferable methods.

The spacer of the present invention is formed by cutting a laminated film slit by a bag making machine into
This specifies the insertion position. Select a material having a thickness of 0.1 to 5 mm and having sufficient slip and elasticity when contacting the HS part, for example, a metal plate such as a steel plate, an aluminum plate, a stainless steel plate, a brass plate, or a fluorine plate. A plate made of a material coated with a resin, silicone, or the like, or a synthetic resin plate made of a fluororesin, polyamide, polyimide, ultrahigh-molecular-weight polyethylene, or the like can be used. Then, the position where the speser is attached to the bag making machine may be set at any one of or before or after applying the rounded-cut portion with the round-cutting die on the laminated film provided with the slit portion, or both. it can. The spacers are fixed with clips or corresponding jigs on, for example, horizontal bars provided on the upper surface on which the laminated film runs. If necessary, by providing a groove having a concave shape on the surface where the spacer passes through the laminated film, not only can the position of the spacer be stabilized, but also a spacer made of a material having a little less rigidity can be used. .

The shape of the spacer is not limited to the above-mentioned plate shape, but may be a triangular prism, a trapezoidal quadrangular prism, a pentagonal prism, an ellipse,
It can also be formed as a plate having an oval or egg-shaped cross section. In such a case, it is preferable to provide a narrow portion at a position separating the slit portion of the laminated film. The length of the spacer (the size corresponding to the flow direction of the film) may be such that it can enter the installation space using the above-mentioned material, and can maintain the running of the film accurately without losing the rigidity. The width (thickness) of the spacer
Is preferably 0.1 to 5 mm, and 0.1 m if rigid.
Even if it is not more than m, the separation of the laminated film can be sufficiently performed by being installed obliquely. On the other hand, if it exceeds 5 mm, there is a problem that it has to be inserted into a position far from the slit.

By setting the spacer after separating the laminated film and before forming the rounded portion with the rounded die, the rounded portion can be formed without causing wrinkles in the film. . Further, by providing the spacer after forming the rounded portion, the width of the separating portion can be kept constant. Further, a spacer may be provided before and after the rounded portion. The spacer has different widths at the separation part before and after the rounded part (for example, the width before the blade is smaller than or equal to the width of the rounded die).
The width of the separation portion can be stabilized by providing the same. Further, as the spacer, a spacer having a similar ratio of width to length, such as a columnar shape, may be used. In such a case, a plurality of spacers may be arranged in series.

The shape of the tip portion where the spacer comes into contact with and separates from the laminated film and penetrates is a flat shape that is almost straight,
By removing the burrs at the ends, the tear of the laminated film can be prevented. In addition, it is preferably provided in a boat bottom shape, an elliptical shape, an oval shape, an egg shape, or the like. By doing so, the force applied to the laminated film of the spacer,
It is possible to prevent the wrinkles of the laminated film from being generated at the separation portion by reducing the strength at first and then gradually separating it by pressing strongly, and then reducing the strength gradually.

The shape of the rounded die used in the present invention is shown in FIG.
This forms the rounded portions of the rounded portions 20, 21 and 22 of the bag body. Then, the rounded die 25 forms rounds corresponding to the rounded portions 20, 21 and 22 shown in FIG. In addition, the tip widths l and m of the rounding die are set to ± 0.1 to 0.2 mm of the running pitch error of the laminated film in the bag making machine, and usually to ± 0.2% which is a manufacturing error of a predetermined pitch. Is about 0.5 mm, which can correspond to a numerical value obtained by adding 0.2 mm.

The round-cutting die is required to have a sharpness, toughness, abrasion resistance, and corrosion resistance from a steel material for a cutting tool that is used for punching a laminated film. In addition to metals such as steel and pig iron, an arbitrary material is used from stainless steel or an alloy of iron and vanadium, chrome, molybdenum, silicon, copper, and the like. Then, it is made of a material having a balance of toughness, wear resistance, corrosion resistance and hardness by heat treatment such as quenching and tempering. Then, an arm for mounting is provided at a rounded punching portion on the bag making machine, and punching is performed by vertical movement of an air cylinder.

The cutting is performed at the horizontal HS section 16 after rounding is performed, and then a rounded rounding die 17 is formed at a cutting position 17.
And 18 with a cutting blade. The cutting can be performed with one cutting blade instead of stopping the film. However, there is a problem that the bag making speed is reduced and it is difficult to control the stop position. For the purpose of avoiding this, a so-called double-cut method in which the laminated film is cut once at the cutting position 18 and only the cutting blade is moved to the cutting position 17 while the film is fixed is a highly efficient and preferable method. The moving distance of the cutting blade is 0.2 to 5 mm although it depends on the width l of the tip of the rounding die 25 and the feeding accuracy of the machine.

Hereinafter, the present invention will be described in more detail based on experimental examples. (Example) A biaxially stretched polyester film having a thickness of 12 μm, an aluminum foil having a thickness of 9 μm, and an unstretched polypropylene film having a thickness of 70 μm as an HS layer were provided with a polyester-isocyanate-based adhesive layer and dry-laminated. A laminated film 6 used in this example was prepared. As shown in FIGS. 8 and 1, the laminated film 6 is bent from the paper feeding unit 60 of the bag making machine 100 by the half-folding unit 7 so that the HS layers face each other, and the vertical HS
The unit was hot-pressed with a hot plate of the unit 71 and further cooled by a vertical seal cooling unit 72 through which cooling water was passed to form vertical HS units 11 and 12. Then, it is thermocompression-bonded with the hot plate of the horizontal HS unit 73, and further, the horizontal seal cooling unit 7 through which cooling water is passed.
4 to form a horizontal HS portion 16. Furthermore, the slit blade 76 is inserted by the side trimming unit 75,
The vertical slit portions 3 were formed at the same time as the vertical HS portions were trimmed by applying the trimming portions 31 and 32. The spacer 1 is inserted into the slit part 3 by the spacer insertion unit 77, and the separation part 10 is provided in the laminated film. Separation unit 1
At the position corresponding to the cutting 4 where the horizontal HS portion 16 of 0 is applied, the rounded corner forming units 78 are used to form the rounded corners 20, 21 and 22 using the rounded corner die 25. Then, the spacer 1 </ b> A is inserted again into the separation part 10, and
The S portion was cut at the cut positions 17 and 18 of the rounded corners, and cut corners 41A and 42A were provided to form a three-sided HS bag body 50 having an unHS portion 8.

Since the four corners of the three-sided HS bag body 50 formed as described above are formed by the rounded portions of the rounded portions 20, 21 and 22, all of them are located at the center of the corner and have rounded corners. It was good without having the step 5 or 51 shown in FIG. 3 or FIG.

[0024]

As described in detail above, the three-way HS
The bag is formed on a bag making machine by inserting a spacer into the separation portion of the slit portion of the laminated film having the vertical HS portion and the horizontal HS portion and determining the position, and providing a rounded portion with a rounded die. The round-cutting die is formed in an R-shape by providing a leading end width at the leading end of the punch, which is a margin of a vertical punching portion and a horizontal punching portion corresponding to the meandering and pitch fluctuation of the laminated film. Therefore, the cut end portion cut at the rounded portion of the rounded portion has an effect of forming a good arc shape without generating a step.

[Brief description of the drawings]

FIG. 1 is a basic conceptual diagram showing a shape change of a laminated film on a bag making machine for explaining the formation of rounded corners of the present invention.

FIG. 2 is a diagram showing the shape of an ideal rounded die.

FIG. 3 is a diagram showing the shape of an ideal rounded portion of the bag body.

FIG. 4 is a view showing an example of a shape of a step caused by a shift in a cutting position when a rounded corner is manufactured by a conventional bag making inline machine.

FIG. 5 is a schematic plan view showing the shape of a rounded die.

FIG. 6 is a view showing a shape of a rounded corner formed by a normal bag making in-line rounded corner manufacturing machine.

FIG. 7 is a conceptual diagram for explaining that a horizontal HS portion of the bag body of the present invention is cut twice to eliminate a step.

FIG. 8 is a schematic cross-sectional view showing a flow of a laminated film in a bag making machine that performs in-line rounded corner production.

[Explanation of symbols]

 1, 1A Spacer 2, 20, 21, 22 Rounded section 3 Slit section 4 41, 42 Cutting section 5, 51 Step 6 Laminated film 7 Half-fold unit 8 UnHS section 10 Separation section 11, 12 Vertical HS section 16 Horizontal HS part 17, 18 Cutting position 25 Rounding die 26 Rounding blade 31, 32 Trimming part 41A, 42A Cutting corner 50 Three-way HS bag 71 Vertical HS unit 72 Vertical HS cooling unit 73 Horizontal HS unit 74 Horizontal HS cooling Unit 75 Side trimming unit 76 Slit blade 77 Spacer insertion part 78 Rounding unit 79 Cutting blade 100 Bag making machine l, m

Claims (1)

[Claims] 1. A bag making machine for producing a bag having at least three corners of a laminated film having a heat sealant layer and having a rounded corner at a corner thereof and a non-heat-sealed portion at the end for filling. A slit is formed at the center of the film of the bag body adjacent in the vertical direction, a rounding die is inserted into a separating portion formed by inserting a spacer, and a rounded shape is punched out to form a rounded portion. Before and after the center of the rounded corner 2
A method for manufacturing a bag, comprising cutting at a location.