JPH0577506B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing square-bottomed bags with square bottoms made of paper, plastic film, or the like.

[Prior Art] An example of a conventional method for manufacturing a square bottom bag is as shown in FIG. Paste them together, then lower edge 4
After pasting together the inner surfaces of the bag material 1, fold it upward along the horizontal folding line 5 to form the bag material 1 as shown in FIG.
This bent and glued portion is further bent upward as shown in FIG. 28 and is glued 7 to the surface 6 of the bag material 1 to form a bottom adhesive portion 8. Next, while opening the upper edge 9 side of the bag material 1 and making it into a square shape to form the side surfaces 10, as shown in FIG. 10 is a vertical plane down to the bottom, and the bottom surface 11 of the square
, and when the lower part of the side surface 10 is bent from the folding line 12 toward the bottom surface 11 side and adhered to the bottom surface 11, a third
As shown in Figure 0, a square bottom bag is produced which has a square bottom surface 11 and whose upper edge 9 is opened in a square shape.

To explain another conventional manufacturing method of square bottom bags, as shown in FIG. 26, after the left side edge 2 and right side edge 3 of a square bag material 1 are laminated together,
Fold the entire body into a rectangular cylindrical shape, fold the lower part of the side surface 6 horizontally inward as shown in FIG. 6. By folding the lower trapezoidal portion inward along the folding line 13 and pasting them together, a square bottom bag with a square bottom surface 14 and a square opening at the upper edge 9 as shown in FIG. 32 is created. .

To explain still another conventional manufacturing method of square-bottomed bags, as shown in FIG. Fold it so that it becomes cylindrical, and fold it inward while making a longitudinal crease 15 at the center of the lower part of the side surface 10, as shown in FIG. 33, so that the lower edges 4, 4 of the surface 6 approach each other. and glue
As shown in FIG. 34, the bottom adhesive portion 16 is formed. Next, while keeping the lower part of the surface 6 horizontal, the bottom adhesive part 16 is folded horizontally as shown in FIG. As a result, a square bottom bag with a square opening at the upper edge 9 is produced.

[Problems to be Solved by the Invention] All conventional methods for manufacturing square-bottomed bags require complicated folding and gluing operations, and have the disadvantage of being complicated and inefficient.

The present invention aims to provide a method for manufacturing a square bottom bag that can be carried out efficiently through simple folding and welding operations.

[Means for Solving the Problems] The present invention provides a rectangular laminate material in which an inner material and an outer material having a lower melting point than the inner material are integrated. Folding both sides of the laminate material inward along the longitudinal centerline of the material, then folding the laminate material along the lateral centerline in a direction in which both side edges are exposed to the outside, and further folding the laminate material along the lateral centerline. The laminate material is folded in a direction in which the left and right edges are folded inward along two folding lines parallel to the lateral center line at equal intervals above and below, and the longitudinal direction of the bent laminate material is A method for producing a square bottom bag, characterized in that the directional center portion is sandwiched between heating elements for welding from both sides, and the outer sides of the left side edge and the outer sides of the right side edge are welded. be.

The present invention also provides a method for forming a laminate at a slight distance above and below the lateral centerline of the laminate, with a right-angled vertex on each of the left side edge and the right side edge facing toward the longitudinal centerline of the laminate. Two right-angled triangular notches of the same shape are provided each, and when both left and right edges of the laminate material are bent inward so that the left and right edges of the laminate material are aligned with the longitudinal center line of the laminate material, the left and right edges The two notches face each other with the longitudinal centerline of the laminate as a boundary, and two diagonal square notches are formed above and below the lateral centerline with a slight distance apart. It is also possible to use a laminate material made of

[Function] When the vertical center of the folded laminate material is heated by hot plate heating (or heat roll) or dielectric heating or ultrasonic heating using heating elements for welding held between both sides,
The side edges of the low melting point outer material are fused together to form a square bottom bag.

[Example] Examples of the present invention will be described below.

Fig. 1 shows a rectangular laminate material 20 used to manufacture square bottom bags, and as shown in the enlarged cross-sectional view of Fig. 2, this rectangular laminate material 20 has an inner material 21 and an outer material 21. The material 22 is integrally joined. The inner material 21 is the inside of the square bottom bag, and the outer material 22 is the outside of the square bottom bag.
A material having a lower melting point than the inner material 21 is used. The inner material 21 includes paper, biaxially oriented polypropylene, oriented polyester, oriented polyamide, cellophane, aluminum foil, oriented polystyrene,
Polycarbonate or the like is used, and as the low melting point outer material 22, low density polyethylene, medium density polyethylene, high density polyethylene, linear polyethylene, polyvinyl acetate, polypropylene, polyester, polyamide, etc. can be used. The point is that there is a difference in melting point, and the outer material 22 only needs to have a lower melting point than the inner material 21.

The left side edge 23 and right side edge 24 of such a rectangular laminate material 20 are bent to align with the longitudinal center line 25 of the laminate material 20 so that the inner material 21 is on the inside, as shown in FIG. state. The laminate material 20 bent as shown in FIG. 3 is then bent along the lateral center line 26 in a direction in which the left side edge 23 and the right side edge 24 are exposed to the outside to form the state shown in FIG. 4, Furthermore, above and below the lateral center line 26 (as seen in the state shown in Figure 3)
The laminate material 20 is folded along two folding lines 28, 28 parallel to the lateral center line 26 with an interval 27, 27 equal to the direction in which the left side edge 23 and the right side edge 24 are folded inward. As shown in FIGS. 5 to 7, the laminate material 20 has a chevron portion 29 at the lateral center line 26,
The inner material 21 faces each other inside the folded laminate material 20 as shown in FIGS. As shown in FIG. 8, the outer material 2
The two will face each other.

After applying a release agent to the lower surface 31 of the chevron portion 30 on the lower side of the laminate material 20 bent in this way,
As shown in FIG. 10, the vertical center of the laminate material 20 is sealed from both sides with a square rod-shaped heat seal bar,
It is sandwiched between electrode plates 32, 32 for welding, such as ultrasonic oscillation bars. In this case, a release agent is applied to the surfaces of the electrode plates 32, 32 for welding that are in contact with the laminate material 20. When the longitudinal center of the laminate material 20 is heated by the welding electrode plates 32, 32 at a temperature below the melting point of the inner material 21 and above the melting point of the outer material 22, which has a lower melting point, the laminate material 2
The materials 22, 22 on the outside of the left side edges 23, 23 and the materials 22, 22 on the outside of the right side edges 24, 24 (see Fig. 8) are in contact with each other inside the longitudinal center of 0. The left side edges 23, 23 are melted and integrated as shown in FIGS. 11 to 14.
and the right side edges 24, 24 are welded together.

The laminate material 20 thus made is shown in FIG.
As shown in FIG. 16, when the open upper edge 33 is opened and the lower chevron portion 30 is pressed downward and flattened, the upper chevron portion 29 moves left and right and welds. It is a vertical flat surface except for the left side edges 23, 23 and the right side edges 24, 24,
As shown in FIGS. 17 and 18, it is possible to obtain a square bottom bag 36 having a rectangular flat bottom 34 and vertical flat sides 35. Left side edges 23, 23 and right side edge 2 welded to each other
4 and 24 protrude inward from the square bottom bag 36 along the longitudinal center line of the side surface 35, and the lower part of the left side edge 23 and the lower part of the right side edge 24 are formed as shown in FIGS. 15 and 17. The square bottom bag 3 forms a triangular protrusion 37.
It protrudes inside 6.

In FIG. 19, instead of the rectangular bar-shaped welding electrode plates 32, 32 shown in FIG. between the outer sides and the right side edges 24, 24
In this case, the entire interior of the triangular protrusion 37 shown in FIG. 20 is welded.

The embodiment shown in FIG. 21 laminates a right-angled apex 38 on each of the left side edge 23 and the right side edge 24 at a short distance above and below the lateral centerline 26 of the laminate 20. Two identical right triangular notches 39 are provided each facing the longitudinal center line 25 side of the material 20, and the longitudinal center line 2
5, the left side edge 23 as shown in FIG.
When the right side edge 24 and the right side edge 24 are bent inward, the two left and right notches 39 face each other with the vertical center line 25 as a boundary, and are separated by a small distance above and below the horizontal center line 26. As a result, two square notches are formed at an angle of 45 degrees.

The laminate material 20 that has been bent into the state shown in FIG. 22 is bent along the lateral center line 26 in a direction in which the left side edge 23 and right side edge 24 are exposed to the outside to form the state shown in FIG. Vertex 38 of
When the laminate material 20 is folded in a direction in which the left side edge 23 and the right side edge 24 are folded inward along two folding lines 28, 28 passing through the lateral centerline 26, as shown in FIG. is Yamagata part 2
9, and the notches 39 having apexes 38 perpendicular to the folding line 28 on both sides overlap each other.

The laminate material 20 bent in this way is
When the dovetail-shaped welding electrodes 32, 32 shown in FIG. , 24 and between the outer sides of the notches 39, 39 are welded. The laminate material 20 made in this way was
When opened in the same manner as in the case described with reference to FIGS. 17 to 17, the triangular protrusion 37 shown in FIGS. 15, 17, and 20 is not present, and the welded parts have the same width as shown in FIG. 25. A square bottom bag 36 shown in FIG. 1 can be obtained.

[Effects of the Invention] According to the present invention, a square bottom bag can be efficiently produced in a single welding operation without repeating the complicated gluing operation many times as in the conventional method.

In addition, the welded side edges face toward the inside of the square bottom bag and do not protrude outward, making it convenient for packing into boxes.Depending on the internal pressure from the contents, the welded side edges Although it is difficult to peel off, it is easy to tear from the outside.Since the laminate material is made up of an inner material and an outer material, the inner material is made of a material that does not have a negative effect on food, etc., so that food, etc. does not deteriorate. You can do it like this. Furthermore, the invention of claim 2 has the effect of reducing the number of protrusions into the square bottom bag.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the laminate material, Figure 2 is a partially enlarged sectional view of the laminate material, Figures 3 to 5 are perspective views showing the order in which the laminate material is folded, and Figure 6 is the same as in Figure 5. - sectional view, Fig. 7 is a plan view of Fig. 5, Fig. 8 is a partially enlarged cross-sectional view of Fig. 7, Fig. 9 is a - sectional view of Fig. 8, Fig. 10
The figure is a perspective view showing a state in which a laminate material is sandwiched between electrode plates for welding, FIG. 11 is a perspective view of a laminate material with side edges welded, and FIG. FIG. 13 is a cross-sectional view of FIG. 12, FIGS. 14 to 17 are perspective views showing the state in which the laminate material with the side edges welded is opened, and FIG. 18 is a square bottom manufactured by the method of the present invention. Perspective view of bag, No. 19
The figure is a perspective view showing a state in which the laminate material is sandwiched between welding electrodes different from those in Figure 10, and Figure 20 is a
A perspective view showing the open state of the laminate material whose side edges are welded using the welding electrode shown in Fig. 21.
The figure is a front view of another invention of the laminate material, Figures 22 to 25 are perspective views showing the order of manufacturing a square bottom bag using the laminate material of Figure 21, and Figures 26 to 35 are the conventional one. It is a perspective view showing the manufacturing method of the square bottom bag in . 1...Bag material, 2...Left side edge, 3...Right side edge, 4...Lower edge, 5...Folding line, 6...Surface,
7...Adhesion, 8...Bottom adhesive part, 9...Top edge, 1
0... Side surface, 11... Bottom surface, 12, 13... Folding line, 14... Bottom surface, 15... Vertical fold, 16...
... Bottom adhesive part, 17 ... Bottom surface, 20 ... Laminate material, 21 ... Inner material, 22 ... Outer material, 23 ... Left side edge, 24 ... Left side edge, 25
...Vertical center line, 26... Horizontal center line, 27
... Interval, 28 ... Folding line, 29, 30 ... Chevron section, 31 ... Bottom surface, 32 ... Plate for welding, 33 ...
...Top edge, 34...Bottom surface, 35...Side surface, 36...
Square bottom bag, 37...Triangular protrusion, 38...Right angle apex, 39...Notch.

Claims (1)

[Scope of Claims] 1. A rectangular laminate material made by integrating an inner material and an outer material with a lower melting point than the inner material, with the left and right edges of the laminate material aligned with the longitudinal center line of the laminate material. Fold both sides of the laminate material inward to match the laminate material, then fold the laminate material along the lateral center line in a direction in which both side edges are exposed to the outside, and then fold the laminate material upward and downward from the lateral center line. The laminate material is folded in a direction in which the left and right edges are folded inward along two folding lines parallel to the lateral center line at equal intervals, and the vertical center of the bent laminate material is folded from both sides. A method for manufacturing a square bottom bag, characterized in that the left side edges and the right side edges are welded together by sandwiching them between heating elements for welding. 2 At a short distance above and below the lateral centerline of the laminate, on each of the left side edge and the right side edge, an identical right angle with the apex of the right angle facing the longitudinal centerline of the laminate. Two triangular notches are provided each, and when both left and right edges of the laminate material are bent inward so that the left and right edges of the laminate material are aligned with the longitudinal center line of the laminate material, the two notches on the left and right edges are formed. The sections face each other with the longitudinal centerline of the laminate as the boundary, and two diagonal square cutouts are formed at a slight distance above and below the lateral centerline. 2. The method for manufacturing a square bottom bag according to claim 1.