JP3314105B2 - Manufacturing method of packaging bag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing method suitable for obtaining a packaging bag excellent in handling and safety, particularly a self-supporting packaging bag.

[0002]

2. Description of the Related Art Conventionally, packaging bags in which two sheets or films each having a heat-adhesive synthetic resin layer on the inner surface are superposed and the both sides and the bottom are heat-bonded have been widely used. Sheets of a multi-layer composite structure or metal foil with a laminated thickness are also used, but since the surrounding thermal bonding is so-called palm joint, hard sharp corners are easily formed at the four corners of the bag . For this reason, there is a great risk that the bags may be damaged or broken due to contact between the bags, or the fingers may be injured during handling.

[0003] A so-called corner cut is also performed in which a corner of a bag is cut off in an arc shape or a diagonal line. Usually, when such a packaging bag is manufactured continuously, a plurality of adjacent bag bodies are cut. After the bottom and side edges are heat-bonded with a seal bar, a portion to be a corner of the bag is punched out in advance with a blade mold, and corners of the adjacent bags are subjected to corner cutting, and in the next step, adjacent corners are formed. The bag is cut and separated into individual units, and it is difficult to accurately match the position of the corner cut line punched first by the blade type with the cutting line of the bag, so the positions of both are cut off. Deviation is likely to occur.

[0004] Due to this misalignment, an acute-angled end 31 called a so-called dent is formed at the end of the corner cut line 6 of the obtained bag body 1 as shown in FIG. In addition, there is a problem in that the appearance of the product is impaired or the like, and it is difficult to obtain a sufficient effect even if corner cutting is performed.

[0005] In particular, two side wrappings made of a relatively rigid synthetic resin composite film in which metal foils and the like are laminated are superimposed, and a bottom wrapping which is folded in two and has a bent portion is inserted under the two side wrappings. A self-supporting packaging bag, which is a bag in which both side edges of the side packaging material and the side packaging material and the bottom packaging material are thermally bonded, and the bottom portion is configured to open and become self-supporting when the contents are accommodated,
Since the corners at both lower ends are formed of four pieces of packaging material, the rigidity is high, and the sharpness is further enhanced.

[0006]

As a result of various studies to improve the above-mentioned drawbacks in the conventional method of manufacturing a packaging bag, the present inventor conducted thermal bonding of the bag using a specific seal bar. The knowledge that a bag that is excellent in handling, safety, and the like and that does not cause inconvenience due to the corner cut unlike conventional products can be obtained by performing the corner cut after the completion, and the present invention has been achieved.

An object of the present invention is to provide a manufacturing method capable of preventing damage and breakage due to contact between bags and the like, and capable of easily obtaining a safe and easy-to-handle packaging bag.

[0008]

In order to achieve the above-mentioned object, the present invention is to superimpose a side wrapping material having a heat-adhesive inner layer, and to heat the bottom portion and a side edge portion shared by adjacent bags. In manufacturing a packaging bag continuously by bonding, heat sealing is performed using a seal bar having a concave portion or a through-hole having a contour crossing the corner of the bag, so that the bag is not positioned at the corner of the bag. Forming a seal portion, then punching and positioning a blade having a shape substantially similar to the contour of the concave portion or the through hole of the seal bar and having a small size in the non-seal portion, and performing a corner cut, thereby forming a corner cut line. A band-shaped non-seal portion is formed substantially along, and then adjacent bag bodies are separated and cut to obtain a packaging bag.

[0009] Further, when a side wrapping material having a heat-adhesive inner surface layer is overlapped and a bottom portion and a side edge portion shared by each adjacent bag body are thermally bonded to produce a packaging bag, a corner portion of the bag body is produced. After heat-bonding using a seal bar having a concave portion or a through hole at a position corresponding to the non-seal portion so as to leave a non-seal portion in a contact area between a corner cut line traversing the cutting line and a cutting line of the bag body, A punch having a contour crossing the corner of the bag body is positioned at the corner of the bag body, punched out, and subjected to corner cutting.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the method of the present invention will be described with reference to the drawings, taking a continuous production method of a self-supporting packaging bag as an example. FIG. 1 is a plan view schematically showing an example of an apparatus used for carrying out the method of the present invention, and FIG.
6 is a cross-sectional view of a state in which the bag is thermally bonded, FIG. 3 is an enlarged plan view of a corner portion (A portion in FIG. 1) of an adjacent bag, FIG.
Is a sectional view of a state in which the non-seal portion is cut by the blade mold 20;
FIG. 5 shows the contour 17a of the recess of the seal bar and the contour 20 of the blade mold.
a is an enlarged plan view illustrating a, FIG. 6 is a front view of the obtained bag,
FIG. 7 is a plan view showing a non-seal portion in a contact area between the corner cut line 6 and the cutting line of the bag, and FIG. 8 shows a dent portion 31 of the bag.

In FIG. 1, 2 is unrolled from the roll.
Long laminated films are arranged on the top and bottom,
2a. After the bottom wrapping materials 3 and 3 are folded in two, punching holes 8 are pierced at appropriate intervals by a piercing machine 11 and inserted into both sides between the side wrapping materials 2 and 2a with the bent portion inside. As the side wrapping materials 2 and 2a and the bottom wrapping material 3, known composite films used for this kind of bag, for example, having desired rigidity, heat resistance, light shielding properties, barrier properties, and the like.
Polypropylene, polyester, nylon, cellophane, a composite film appropriately laminated aluminum foil and the like,
One having a heat-adhesive layer such as polyethylene formed on the inner surface may be used.

The side wrapping materials 2 and 2a and the bottom wrapping materials 3 and 3 are thermally bonded by applying a seal bar 13 heated by a bottom sealing mechanism 12, and a bottom thermal bonding having an upper edge curved in a concave shape. The part 4 is formed. As described above, the bottom packaging material 3,
A punching hole 8 is formed in the hole 3, and the side wrapping materials 2 and 2a are thermally bonded to each other at the punching hole 8, and the punching hole 8 is located at both ends of the bottom thermal bonding portion 4 of the bag body. become.

The seal bar 13 for forming the bottom heat bonding portion in the bottom seal mechanism 12 has a concave portion (or through hole) 14 having a profile crossing the bottom corner of the bag body.

Next, a seal bar 16 is applied to the side edge portion of the bag body by a side edge sealing mechanism 15 to be thermally bonded.
The side edge thermal bonding part 5 which is common to each bag body adjacent in the traveling direction is formed. That is, the bottom of the bag is located on both sides,
The upper portions of the bags are connected at the center, and the packaging bags forming a pair on both the left and right sides in the traveling direction are continuous with the side edge thermal bonding portions 5 shared in the traveling direction.

As shown in FIG. 2, the seal bar 16 used for thermal bonding of the side edges of the side edge sealing mechanism 15 also has a concave portion 17 having a profile crossing the corner of the bag. In the present embodiment, the side edges of the bag body adjacent to the traveling direction and the two rows of bag bodies adjacent to the left and right sides in the traveling direction are thermally bonded at a time, so that at the center position where the two rows are adjacent, The recess 17 of the seal bar 16 is
It has a substantially rhombic shape surrounded by a plurality of arc-shaped (or straight-line) contours 17a, and the intersection of the cutting lines I and II for cutting the bags adjacent to each other later and the recess 17 of the seal bar. Pressing is performed so that the center is aligned, and thermal bonding is performed.

After the above-mentioned heat bonding step,
A substantially star-shaped or diamond-shaped non-sealed portion surrounded by the contour 17a of the concave portion 17 of the seal bar as shown in FIG. That is, a substantially triangular non-seal portion having a long side in an arc shape or a straight line is formed in a portion to be a corner portion of each bag body.

At the positions corresponding to both side edges, that is, the corners of the bottom of the package, which form a pair on both the left and right sides in the traveling direction, the shape of the concave portion of the seal bar 16 is substantially half of the above shape in the vertical direction. Shape.

Next, a punch having a shape substantially similar to the shape of the concave portion 17 of the seal bar and having a small size is positioned in the non-seal portion as shown in FIG. A corner cut is performed to form a band-shaped non-seal portion substantially along the corner cut line. That is, the blade mold 20 can be described with reference to FIG.
a, which is substantially similar in shape to the contour 17a of the recess of the seal bar and has a small size, for example, the contours 17a and 20a.
The distance from “a” (the band-shaped non-seal portion 7) may be about 1 to 2 mm although it depends on the size of the bag to be manufactured. In addition, the contour 1 of the concave portion of the seal bar
The contour 7a and the blade-shaped contour 20a may be circular (or may be elliptical) as shown in FIG.

As described above, the non-sealed portion is formed by thermally bonding the bottom portion and the side edge portion, and after the non-sealed portion is punched by the blade die, the cutting lines I and II of the adjacent bag bodies are cut. Is cut and separated to obtain each bag.

As shown in FIG. 5, the obtained self-supporting packaging bag 1 has corner cut lines 6 at four corners and a band-shaped non-seal portion 7 is formed along the corner cut lines 6. Become. That is, the seven portions at both ends of the opening portion 9 of the bag are in a state in which the two side packaging materials 2 and 2a are separated, and the non-seal portions 7 at both ends at the bottom are two pieces obtained by folding the bottom packaging material 3 in two. And two side wrapping materials, that is, a total of four wrapping materials are formed separately from each other.

The bag is filled with the contents and the opening is sealed to complete bag making and filling and packaging. The filling and packaging step of the contents can be performed in an aseptic automatic packaging machine.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. The shape of the concave portion of the seal bar, for example, at the center position of the seal bar 17 at the side edge portion, is thermally bonded using a contour as shown in FIG. By leaving a non-seal portion 7b in advance in the contact area between the cut line 6 and the cut lines I and II of the bag, and then performing a corner cut along the corner cut line 6, a buffer region is formed at the end of the corner cut line. Is done. Even when a dent is formed, the sharpness of the dent part can be eliminated and a buffering effect can be achieved.

[0023]

As described above, according to the method of the present invention, the corners are cut at the corners, and the edges of the corner cuts are separated into two to four pieces without the heat bonding of the packaging material, and are flexible. It is possible to easily manufacture a bag in which a buffer region that can be bent by a high elasticity is formed. Therefore, the obtained packaging bag can prevent the occurrence of accidents such as breakage or injury due to the contact of the corners, and is safe and easy to handle. Furthermore, even if a dent-shaped portion is formed at the end of the corner cut line due to a positional deviation between the corner cut line and the cutting line of each unit, the buffer region has a buffer area that can be bent by flexible elasticity. There is no danger as in the past. In addition, since the non-seal portion is slightly formed at the edge of the corner cut, the adhesive strength near the corner of the bag body is not impaired at all.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing an example of an apparatus used for carrying out the method of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a bag is thermally bonded by a seal bar 16;

FIG. 3 is an enlarged plan view of the vicinity of a corner of an adjacent bag body (A portion in FIG. 1).

FIG. 4 is a cross-sectional view showing a state of being cut by a blade mold 20.

FIG. 5 shows the outline 17a of the recess of the seal bar and the outline 2 of the blade mold.
It is an enlarged plan view which illustrates 0a.

FIG. 6 is a front view of the bag 1 obtained.

FIG. 7 is a plan view showing a non-sealing portion 7b in a contact area between a corner cut line 6 and a cutting line of the bag body.

FIG. 8 is a front view showing a dent portion 31 of the bag 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bag body 2 and 2a Side wrapping material 3 Bottom wrapping material 4 Bottom heat bonding part 5 Side edge heat bonding part 6 Corner cut line 7 Band-shaped non-seal part 13, 16 Seal bar 17 Seal bar concave part 17a Seal bar concave part Contour 20 Blade type 20a Profile of blade type

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B31B 37/64 B31B 37/14 B65D 33/00

Claims (3)

(57) [Claims] 1. A bag for continuously manufacturing a packaging bag by superposing side wrapping materials having a heat-adhesive inner surface layer and thermally bonding a bottom portion and a side edge shared by each of the adjacent bags. A non-seal portion is formed at a corner of the bag body by heat bonding using a seal bar having a concave portion or a through hole having a contour crossing the corner of the seal bar, and then the concave portion or the through hole of the seal bar. A blade having a shape substantially similar to the outline of the above and having a small size is positioned in the non-seal portion and punched, and a corner cut is performed to form a band-shaped non-seal portion substantially along the corner cut line, and thereafter, an adjacent shape is formed. A method for producing a packaging bag, comprising separating and cutting a bag body to obtain a packaging bag. 2. A packaging bag, wherein two side wrapping materials are overlapped, and a bottom wrapping material having a folded portion as an upper portion is inserted into a lower portion of the two wrapping portions, and both side edges and a side edge and a bottom portion are heated. The method for producing a packaging bag according to claim 1, wherein the packaging bag is a self-supporting packaging bag that is adhered. 3. A side wall wrapping material having a heat-adhesive inner surface layer is overlapped, and a bottom portion and a side edge portion shared by each adjacent bag body are thermally bonded to produce a packaging bag. After heat-bonding using a seal bar having a concave portion or a through hole at a position corresponding to the non-seal portion so as to leave a non-seal portion in the contact area between the corner cut line traversing and the cutting line of the bag body,
A method for manufacturing a packaging bag, characterized in that a cutting die having a profile crossing a corner of a bag is positioned at the corner of the bag, punched out, and subjected to corner cutting.