JP4336242B2 - Bag manufacturing method - Google Patents

Description

The present invention relates to a bag manufacturing method .

Japanese Industrial Standards (JIS) Z1531 Kraft Paper Bags-General Table 1 B-1 (double-bottomed bag without pleats) or A-1 (single-bottomed bag without pleats) standard In general, the so-called “PV bag” used to store powders such as mixed powder, starch powder, corn starch, and yeast is usually produced as follows.
(1) Printing on the outermost layer of kraft paper, which is a base paper for bags, using a rotary printing machine.
(2) Send the long multi-layer paper to a bag making machine called a tuber, paste the cylinders of each layer and apply point glue on the upper and lower ends, then cut to form a tube of appropriate length, and make the tube easy to handle 20 to 30 sheets are stacked and bundled and discharged from the bag making machine.
(3) In an automatic bottom pasting machine called “bottomer”, the tubes are taken out one by one at a right angle, continuously run while regulating the edges, and the bottom is closed.

To close the bag bottom, fold the left and right ends of the bag mouth in a triangular shape, and then apply adhesive to the inner surface of the front or rear end of the bag mouth. It folds inward from the fold line along, superposes, and sticks (refer patent document 1).
In the case of a double-sided bag, the front and rear edges are glued after a cylindrical valve paper piece serving as a filling port is attached to one side of one bag bottom.
At this time, in order to accurately fold the front and rear edges of the bag mouth along the fold line, a ship-bottom plate called a molding plate is overlapped on the bag mouth and folded inward along the edge of the molding plate.

When using a molded plate as described above, if the molded plate is placed on the glued part, the adhesive adheres to the molded plate, and particularly when a valve paper piece is attached, it is rubbed by the molded plate. Since there is a possibility that the valve paper piece may not open as a result of the adhesive being attached, it has been necessary to inspect the opening of the filling port.
Therefore, conventionally, as shown in FIG. 6, the adhesive c is applied to the outside of the front and rear folding lines a and b. However, since the bags manufactured in this way are not glued at both ends of the front and rear folding lines a and b, powder leakage due to air backflow during powder filling or residual air is stored and loaded. It is easy for powder leakage to occur. In particular, when the valve paper piece d is attached, the folded portion becomes thicker and powder leakage is more likely to occur from the gap.

  In addition, after passing through the molding plate, it is possible to spray the adhesive close to the air gun for a short time just before closing the bag bottom, or to fold without applying adhesive to crease with a separate folding section. After that, it is also known to attach the adhesive after opening the bottom and fold it without using the molding plate. However, these methods increase the size and cost of the device. If it goes wrong, there is a disadvantage that the adhesive adheres to unnecessary portions and the operability of the apparatus is significantly impaired.

Japanese Utility Model Publication No. 6-20250

The problem to be solved by the present invention is to provide a bag manufacturing method that can prevent powder leakage by gluing both ends of the front and rear folding lines.

In the bag manufacturing method of the present invention, the front end portion and the rear end portion of the bottom mouth are bent from the folding line along the width direction to the outer surface side, and the both ends of the bottom mouth in the width direction are bent inward to form side bent pieces. After that, the front end portion and the rear end portion of the fold line to the front end side while applying a force pulling in the direction of the tip with a scoring roll, forming a fold line parallel to the fold line, Apply an adhesive along the front edge to the inner surface of the front end portion or the rear end portion of the bottom opening, and apply an adhesive from the front and rear end portions to the inner side of the fold line on the outer surface of the side bent piece, the from the fold line to the front and rear ends of the bottom opening, to form a bent piece longitudinal folded inwardly, respectively, as well as gluing by the adhesive by polymerizing together the leading edge of the front and rear bent piece, the front and rear bent pieces Gluing the front Kise' Chakuzai by polymerization on the outer surface of the side bent piece.
You may apply | coat an adhesive agent to the front-and-back end part and inner edge center part of the outer surface of the said side part bending piece.
It is also possible to apply the adhesive after attaching a cylindrical filling valve paper piece communicating between the inside and outside of the bag to the outer surface of one side bent piece between the front and rear fold lines.

According to the bag manufacturing method of the present invention, a bag without powder leakage can be easily manufactured.
Further, when forming the fold line, the front and rear end portions of the bag mouth are stretched while pulling in the distal direction, so that the fold line can be formed in parallel with the fold line.

Hereinafter, the example regarding a pleatless both bottom sticking bag is described in detail based on a drawing.
As shown in FIG. 8, the bag according to the present invention forms a flat tube 1 by stacking appropriate lengths of multilayer paper for each layer, and has a rectangular bottom 2 at the bottom opening at both axial ends. 3, and a cylindrical filling valve paper piece 4 having both ends opened on one square base 2 is mounted.
In order to form the square bases 2 and 3 by the automatic bottom pasting machine, as shown in FIG. 1, the flat tube 1 is laid down and the axial direction thereof is arranged perpendicular to the machine transfer direction. Then, both axial ends of the front piece 5 and the rear piece 6 are bent at right angles from the folding lines 7 and 7 'along the width direction of the tube 1 to the outer surface side (up and down direction), and from the folding lines 7 and 7'. Also, in the front end portion, the width direction both ends (the transfer direction both ends) of the front piece 5 and the rear piece 6 are folded inward, and the triangle side with the intersection of the fold line 7 and both side edges of the tube 1 as the vertex A partially bent piece 8 is formed.

Further, at one bottom opening, the valve paper piece 4 is attached to the central portion of the outer surface of the side bent piece 8 on one side in the width direction so that the axis thereof is along the width direction of the tube 1.
The above process is the same as the conventional bag making process.
Next, as shown in FIG. 2, the folding lines 10, 11 along the width direction of the tube 1 are arranged on the distal side of the folding lines 7, 7 ′ of the front piece 5 and the rear piece 6 by the scoring roll 17. Streak the position.
The scoring roll 17 includes a female roll 18 and a male roll 19 that sandwich the front piece 5 or the rear piece 6, and is disposed on both upper and lower sides of the transfer path of the tube 1.

As shown in FIG. 3, a groove 20 is formed in the outer periphery of the female roll 18 along the circumferential direction, and a protrusion 21 that fits in the groove 20 of the female roll 18 is formed in the circumferential direction on the outer periphery of the male roll 19. Are formed along.
The cross section of the groove 20 of the female roll 18 is formed in a substantially V shape with an opening angle of about 75 degrees.
The ridge 21 of the male roll 19 has a substantially triangular cross section in which the surface near the folding lines 7 and 7 'is parallel to the main body of the tube 1 and the apex angle is about 50 degrees.
In addition, the bottom part of the groove | channel 20 and the top part of the protrusion 21 are chamfered so that the front piece 5 and the rear piece 6 may not be damaged.
Further, the interval between the female roll 18 and the male roll 19 is narrower from the groove 20 toward the folding lines 7 and 7 ′, and is slightly wider near the front ends of the front piece 5 and the rear piece 6.

The female roll 18 is arranged inside the transfer path of the tube 1, and the male roll 19 is arranged opposite to the outside of the transfer path of the tube 1. Both end portions of the rear piece 6 are fed between the female roll 18 and the male roll 19 facing each other.
The front piece 5 and the rear piece 6 that have passed between the female roll 18 and the male roll 19 are formed with streaks that protrude inward along the folding lines 10 and 11.

Further, by scoring in this way, the front piece 5 and the rear piece 6 tend to shrink in the direction of the folding lines 7 and 7 ′ while passing through the scoring roll 17.
However, as described above, the cross section of the protrusion 21 of the male roll 19 has a horizontal surface (parallel to the tube body 1 ) near the folding lines 7 and 7 ', and the other surface is inclined. Further, a force for pulling the rear piece 6 in the distal direction works, and the distance between the female roll 18 and the male roll 19 is slightly wider near the front ends of the front piece 5 and the rear piece 6, and the front piece 5 is pulled. Since the rear piece 6 can be released in the front end direction, the folding lines 10 and 11 are formed in parallel with the folding lines 7 and 7 '.

Next, as shown in FIG. 4, the adhesive 9 is applied in a substantially triangular shape to the front and rear ends of the outer surface of each side bent piece 8, and the adhesive is applied to the inner edge central portion of the outer surface of the side bent piece 8. 9a is applied in a spot shape. Further, an adhesive 9b is applied to the inner surface of the front piece 5 along both axial end edges.
It should be noted that the adhesive 9 at the front and rear ends of the side bent piece 8 is applied to a position closer to the folding lines 7 and 7 'than the folding lines 10 and 11, and is adhered to the portion where the valve paper piece 4 is attached. The agent 9 is applied so as to reach the outer surface of the valve paper piece 4.

Thereafter, the front end portion of the front piece 5 and the front end portion of the rear piece 6 are folded inward from the folding lines 10 and 11 that are pre-scored, respectively, to form front and rear bent pieces 12 and 13.
At this time, as shown in FIGS. 5 and 6, the fold lines 7 and 7 ′ are slightly pressed by the pair of guide bars 16 along the width direction from the front and rear adhesives 9, respectively, and the front piece 5 and the rear piece 6 are pressed. Fold the tip of the inward.
The guide bar 16 is brought into contact with the front piece 5 and the rear piece 6 at a right angle, and the end portion on the downstream side in the tube 1 transfer direction is inclined so that the height gradually decreases.

Since the folding lines 10 and 11 are pre-scored, when the front ends of the front piece 5 and the rear piece 6 are bent inward by a folding roller or the like installed on the downstream side in the vicinity of the guide bar 16, The front and rear ends of the bag mouth are folded along the folding lines 10 and 11.
Then, as shown in FIG. 7, the front edges of the front bent piece 12 and the rear bent piece 13 are overlapped and glued with an adhesive 9 b, and the front and rear bent pieces 12, 13 are bonded to the outer surface of the side bent piece 8. Glue with agents 9 and 9a.
In the portion where the valve paper piece 4 is mounted, the front and rear bent pieces 12 and 13 are glued to the outer surface of the valve paper piece 4 with an adhesive 9.

Finally, as shown in FIG. 8, the cover pieces 14 are overlapped and attached to the outer surfaces of the square bases 2 and 3, respectively. In addition, if the cover 14 stuck on the other square base 3 is provided with a tear string 15, it is easy to open when the contents are taken out.
The fold lines 10 and 11 are formed along the width direction slightly on the front and rear sides of the center edge of the adhesive 9 in the application range of the adhesive 9 applied to the front and rear ends of the side bent piece 8. Further, the valve paper piece 4 is mounted between the front and rear folding lines 10 and 11.
Therefore, both ends of the fold lines 10 and 11 are securely sealed by the adhesive 9, so that no powder leaks from this portion after filling the contents.

The 1st step of a bag manufacturing process is shown, (A) is a front view, (B) is the figure which looked at the bag bottom part of both sides from the side, respectively. The 2nd step of a bag manufacturing process is shown, (A) is a front view, (B) is the figure which looked at the bag bottom part of both sides from the side, respectively. The principal part sectional drawing of a scoring roll. The 3rd step of a bag manufacturing process is shown, (A) is a front view, (B) is the figure which looked at the bag bottom part of both sides from the side, respectively. The 4th stage of a bag manufacturing process is shown, (A) is a front view, (B) is the figure which looked at the bag bottom part of both sides from the side, respectively. The principal part perspective view of the bag in the middle of front-back bending piece formation. The top view of the bag which shows the 5th step of a bag manufacturing process. The top view of the bag of a completion state. The top view of the bag in the middle of manufacture which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tube 2, 3 Square bottom 4 Valve paper piece 5 Front piece 6 Rear piece 7, 7 'Folding line 8 Side part bending piece 9, 9a, 9b Adhesive 10,11 Folding line 12 Front folding piece 13 Back folding piece 14 Cover piece 15 Tear String 16 Guide Bar 17 Streaking Roll 18 Female Roll 19 Male Roll 20 Groove 21 Projection

Claims (3)

The front end portion and the rear end portion of the bottom opening are bent outward from the folding line along the width direction, and both ends of the bottom opening in the width direction are bent inward to form side bent pieces, and then the front end portion and the rear end portion The front end side or the rear end portion of the bottom mouth is formed by forming a fold line parallel to the fold line by applying a pulling force to the front end side of the fold line of the section with a scoring roll. The adhesive is applied to the inner surface of the bottom side edge along the edge, and the adhesive is applied from the front and rear end portions to the inner side of the fold line on the outer surface of the side bent piece, and then the front and rear end portions of the bottom opening are applied. Folding lines are folded inward from the folding lines to form front and rear folded pieces, the front and rear folded pieces are overlapped with each other and glued with the adhesive, and the front and rear folded pieces are attached to the side folded pieces. Method of manufacturing bags is characterized in that polymerize to glued by the adhesive. The manufacturing method of the bag of Claim 1 which apply | coats an adhesive agent to the front-and-back end part and inner edge center part of the outer surface of the said side part bending piece. The bag according to claim 1 or 2, wherein the adhesive is applied after a cylindrical filling valve paper piece communicating between the inside and outside of the bag is attached to the outer surface of one side folded piece between the front and rear folding lines. Manufacturing method.

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