JPS59187548A - Manufacture of self-erecting packing bag - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a body wall sheet having a heat-adhesive resin layer on the inner surface, which is arranged facing each other, and a bottom wall sheet folded downward in two is attached to the lower end of the body wall sheet. In addition, in the method for manufacturing a self-supporting packaging bag forming a side edge heat-bonded part, while the heat-adhesive resin layer around the folded peak part of the bottom wall sheet in the side edge heat-bonded part is in a heated molten state, This relates to a method for manufacturing a self-supporting packaging bag characterized by cooling and pressurizing the area around the folded peak to form the entire forced cold-press bonded part, and the folded peak part of the bottom wall sheet in the side edge heat bonded part. The adhesive strength of the bag is increased and leakage of liquid juice can be completely prevented, and a self-supporting packaging bag suitable for packaging liquids and pastes can be obtained.

The conventional self-standing packaging bag equipped with a bottom wall sheet has a structure in which a bottom wall sheet bent downward is attached between body wall sheets, and both side edges are simply fixed by thermal bonding. In addition, due to the difference in the thickness of the packaging material at the folded crest of the bottom wall sheet, fine voids remain along the edges of the folded crest in the heat-bonded part of this part, which may cause accidents such as liquid leakage and bag breakage. In addition, since air is enclosed in the edge of the cut-back crest and heat bonded, there are disadvantages such as a hot bond surface with a large number of air bubbles mixed in, resulting in a decrease in bond strength and an unfavorable appearance. As disclosed in Japanese Utility Model Application Publication No. 51-159620, it has been proposed to form a semicircular, elliptical, etc. reinforcing heat-bonded part on the folded peak, but this reinforcing heat-bonded part is Formed by heating and pressing on the edge heat-bonded part,
From the viewpoint of production efficiency and equipment efficiency, the reinforcing heat-bonded part is formed immediately after the side edge heat-bonded part is formed, and the heat-adhesive resin is heated and molten for the side edge heat-bonded part. Even if heat and pressure are applied for reinforcing bonding during the process, it is difficult to completely remove the fine voids that have already been formed. However, as a result of various experimental studies, the present inventors have developed the present invention, which allows the production of self-supporting packaging bags without such drawbacks.

Examples of the present invention will be described below with reference to the drawings. Polyester film, nylon film, cellophane, paper,
A single or multilayer outer layer film with a thickness of approximately 10 to 300μ selected from various materials such as aluminum foil to provide desired performance such as heat resistance, air proofing, light shielding, fragrance retention, and rigidity. A shell wall sheet 3 having a total layer thickness of 50 μm or more is formed by laminating a heat-adhesive resin layer 2 of polyethylene, polypropylene, ethylene-vinyl acetate copolymer, etc. to a thickness of about 20 to 200 μm on the inner surface of the shell sheet 1, and the inner surface is heat-adhesive. A bottom wall sheet) 4fc Japanese Patent Publication No. 40-97, which is arranged facing each other so as to form the resin layer 2, and is folded downward in half at the lower end between the trunk wall sheets 3.
Curved adhesion and oblique adhesion starting from the vicinity of the intersection of the folded peak part 7 of the bottom wall sheet 4 and the side edge thermally bonded part 6 are used to increase the strength of the bottom part as disclosed in Japanese Patent No. 04. Alternatively, it can be attached by thermal bonding using the bottom wall thermal bonding part 5, such as a linear bonding method as disclosed in Japanese Utility Model Publication No. 48-2987, and both side edges of the trunk wall sheet 3 can be attached by thermal bonding. ! In the process of forming the side heat-bonded parts 6 to form a self-supporting packaging bag, the bottom wall sheet 4 in the side heat-bonded parts 6 is immediately chilled or reheated after the side heat-bonded parts 6 are formed. While the heat-adhesive resin layer 2 around the folded peak part 7 is in a heated and molten state, the folded peak part 7 which is the periphery surrounding the folded peak part 7 is formed.
A rectangular shape is formed by cooling and pressurizing at least the upper and lower small areas of the area using a simple press without a heating element, a suppressor equipped with a cooling mechanism that circulates cooling water, or a suppressor installed in a cold air blowing atmosphere. , a forced cold pressure bonding portion 8 having an appropriate shape such as a circle, a semicircle, or a triangle is formed. In the figure, 9 is an unbonded part provided to form the bottom wall thermally bonded part 5 beautifully, 10 is an opening notch formed as necessary, 11 is a side edge of the bottom wall, 12 is a through notch, 13
are microscopic voids.

The body wall sheet 3 is the bottom wall sheet 4 applied to the present invention.
A continuous integral piece with the body wall sheet 3 and formed by bending, or a heat-adhesive resin layer 2a laminated on the outer surface of the outer layer 1a similar to the trunk wall sheet 3, or a heat-adhesive resin layer 2a layered on both sides of the outer layer 1a. This is a structure in which layers 2a and 2b are layered, and the layers are folded downward in half. When the bent bottom wall sheets 40 facing each other have thermal adhesive properties, the bottom wall side edges 11 are fixed by thermal bonding with the opposing thermal adhesive resin layers 2b. When the facing comrades of the sheets 4 do not have thermal adhesive properties, the through notches 12'i are formed in the bottom wall sheet 4 and fixed by the thermal adhesive resin layer 2 on the inner surface of the trunk wall sheet 3, or the bottom wall side Heat-adhesive resin layer 2゜2a on edge 11 edge
The bottom wall side edges 11 are fixed by melting and extrusion to prevent the bottom wall side edges 11 from opening and provide self-supporting performance.

The present invention provides a trunk wall sheet 3 having a heat-adhesive resin layer 2 on the inner surface.
In the manufacturing method of a self-supporting packaging bag, a bottom wall sheet 4 which is folded downward in half is attached to the lower end of the body wall sheet 3, and a side edge heat-bonded part 6 is formed. This is a method for manufacturing a self-supporting packaging bag characterized by cooling and pressurizing the periphery of the folded peak part 7 of the bottom wall sheet 4 in the edge heat bonded part 6 to form a forced cold pressure bonded part 8. , while the heat-adhesive resin layer 2゜2a at the edge of the folded peak part 7 of the bottom wall sheet 4 in the side edge heat-bonded part 6 is in a heated and molten state, the folded peak that is the periphery surrounding the folded peak part 7 is formed. Since the forced cold-press bonding part 8 is formed by cooling and pressurizing at least the upper and lower small areas of the portion 7, the 13 microscopic voids that occur at the edges of the folded peak 7 are completely removed by pressure, and the remaining microscopic voids 13 are removed. In addition to completely eliminating liquid leakage and bag breakage caused by heat bonding, the large number of air bubbles mixed within the heat-bonded surface can also be drastically reduced by pressure welding using cooling pressure, and the remaining air bubbles are also extremely small.
It has a beautiful appearance, and the heat bonding strength of the area is also excellent.
In particular, in order to increase the strength of the bottom part as disclosed in Japanese Patent Publication No. 40-9704, the intersection of the folded peak part 7 of the bottom wall sheet 4 and the side edge thermally bonded part 6 is strengthened. In the case where the bottom wall thermal bonding portion 5 is formed by curved bonding or diagonal bonding using all nearby starting points, in addition to the heating when forming the side edge thermal bonding portion 6, the bottom wall thermal bonding portion 5 is formed. Due to the heating of the nodame, the vicinity of the folded peak part 7 of the bottom wall sheet 4 in the side edge thermally bonded part 6 is heated twice, which increases the generation of air bubbles, resulting in poor appearance and strength. However, by forming the forced cold pressure bonded part 8f by cooling and pressurizing as in the present invention, these problems can be solved and it is extremely effective. is the periphery surrounding the folded peak 7
Since it is formed only in small areas above and below the area, it can be formed using small equipment with low output, which is economically advantageous and has a beautiful appearance.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway front view, and Figure 2 is a partially cut away front view of Figure 1.
3 is an enlarged sectional view taken along line B-B in FIG. 1, and FIG. A sectional view taken along line C-C, and FIG. 6 is an enlarged sectional view corresponding to the third section of the conventional motor. 2... Heat-adhesive resin layer, 3... Trunk wall sheet. 4...Bottom wall sheet, 6...Side edge thermal bonding part, 7.
...Folding mountain part, 8...Forcible cold pressure bonding part applicant
Fujimori Kogyo Co., Ltd. Figure 1 8 - Figure 4 Me Figure 2 or Figure 55

Claims (1)

[Claims] Body wall sheets having heat-adhesive resin layers on the inner surfaces are arranged facing each other, and a bottom wall sheet folded downward in half is attached to the lower end of the body wall sheet, and a side edge heat-bonded part is formed. In the method for manufacturing a flexible packaging bag, while the heat-adhesive resin layer around the folded peaks of the bottom wall sheet in the side edge heat-bonded portion is in a heated and molten state, the periphery of the folded peaks is cooled and pressed. A method for producing a self-supporting packaging bag characterized by forming a cold-pressure bonded portion.