JPH0274324A - Manufacture of fused seal sack - Google Patents

Abstract

PURPOSE:To manufacture a fused seal sack being free from exfoliation and hole-opening in a sealed part by using an oriented plastic film on which a heat seal agent is applied along the periphery of a fold-back line. CONSTITUTION:A fused seal sack is formed in such a manner that, a long oriented film 1 of uniaxially oriented polypropylene or biaxially oriented polyethylene terephthalate, for instance, being used, a heat seal agent 2 is applied beforehand on the substantially central part in the width direction, along the longitudinal direction thereof, the film is folded back at said substantially central part to form a fold-back line 3, the opposite side ends are joined together and the film 1 moved in the direction of an arrow is cut intermittently by a heated blade 6. Since the heated blade 6 is heated to a temperature of the softening point of the film 1 or above on the occasion, the film 1 is fusion-bonded on the opposite sides simultaneously with the cutting and a fused seal part 4 is formed. Since a part 5 on and near the fold-back line of the fused seal part 4 is coated with the heat seal agent 2, the film is fusion-bonded further firmly by the cutting by the heated blade 6, and thus the fused seal sack being free from exfoliation and hole-opening is formed.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing a melt-sealed bag.

[Prior Art] Conventionally, when manufacturing bags from plastic film, a method has been used in which the plastic film is cut into a predetermined size and the periphery of the cut surface is sealed using a seal bar or a seal roll. In this method, in order to prevent the plastic film from adhering to the seal bar or seal roll, the innermost layer is made of P-1 sealing resin, and the outermost layer is made of a plastic film that does not adhere to the seal bar or seal roll. Inner layer resin J: A plastic film with a multilayer structure using a resin with high heat resistance was required. In contrast, using a long plastic film,
The bag is folded back from approximately the center in the width direction, cut at predetermined distances in the longitudinal direction using a heating blade, and simultaneously melt-sealed to form a melt-sealed bag. It had the advantage of being inexpensive to manufacture.

[Problems to be solved by the invention] In the melt-sealed bag made as described above,
During cutting, only the cut surfaces of the plastic film that came into contact with both sides of the heating blade are heat-sealed, which has the advantage that a sealed portion with virtually no adhesive width is formed at both left and right ends of the bag. The bag thus formed had the disadvantage that, due to the elasticity of the plastic film itself during cooling, it was difficult to peel off at the melt-cut seal portion near the folding line and form a hole.

The present invention has been made in view of the above-mentioned drawbacks, and its object is to provide a fusing-sealed bag that does not cause peeling or opening of the fusing-sealed portion near the folding line even when the fusing-sealing is performed. The purpose of the present invention is to provide a method for manufacturing a melt-sealed bag.

[Means for Solving Problems 1] The above object of the present invention is to fold a long stretched plastic film from approximately the center in the width direction, cut it with a heating blade at a predetermined interval in the longitudinal direction, and simultaneously weld the cut surfaces. The present invention has been achieved by a method for producing a fusing seal bag, characterized in that the stretched plastic film is coated with a sealant along the fold line.

[Function] By having the above-mentioned configuration, the method for manufacturing a weld-cut seal bag of the present invention uses a stretched plastic film in which a sealant is applied to heat 1 along the periphery of the fold line. In comparison, the melt-sealed portion near the folding line A can be firmly bonded at a low temperature, and as a result, it is possible to manufacture a melt-sealed bag that does not peel off or open holes in the seal portion.

[Example] Hereinafter, an example showing a preferred embodiment of the present invention will be described based on the drawings.

According to FIG. 1, the melt-sealed bag of the present invention is, for example, -
Using a long stretched plastic film 1 of axially stretched polypropylene or biaxially stretched polyethylene terephthalate,
Along the longitudinal direction, a heat sealing agent 2 is applied in advance to the approximately central portion in the width direction, and the plastic film is folded back from the approximately central portion to form a folding line 3, and the both ends of the plastic film are overlapped, and the plastic film is folded in the direction of the arrow in the figure. It is formed by intermittently cutting the moving film 1 with a heating blade 6. At this time, since the heating blade 6 is heated to a temperature higher than the softening point of the film 1,
At the same time as the film 1 is cut, both sides are welded to form a welded seal portion 4. In addition, since the corner 5 of the folding line of the welding seal portion 4 is coated with P1 to sealant 2, it is more firmly welded by cutting with the heating blade 6, and a welding seal bag without peeling or holes is formed. Ru.

In J3 of the present invention, as the heat sealing agent (a well-known heat sealing agent can be used), for example, an ionomer resin (ionic copolymer of ethylene/acrylic acid copolymer), ethylene-(metallic acid), )-acrylic esters are preferably used.

All of these heat-sealing agents bond firmly at lower temperatures than stretched plastic films. Therefore, 1? is sufficient without further pressing the vicinity of the folding line with a roller or the like? is power can be obtained.

Furthermore, by using a long stretched plastic film, it is possible to continuously manufacture the above-mentioned melt-sealed bags with high strength.

FIG. 2 shows a plan view of a melt-sealed bag manufactured by the method of the present invention, and FIG. 3 shows a cross-sectional view at section 8-A of the melt-sealed bag shown in FIG. 2.

As is clear from FIGS. 2 and 3, the stretched plastic snack film 1, on which a heat sealing agent has been applied in advance on the inner side around the folding line, is folded back from approximately the center in the width direction to form a folding line 3, and Both left and right ends of the stretched plastic film 1 are melt-sealed by a heating blade to form a melt-cut sealed portion 4 with substantially no width.

Since the heat-sealing agent is applied in advance near the bottom of the fusing seal portion 4, the heat-sealing agent bonded portion 5 is formed with particularly strong adhesion during fusing sealing.

In the above embodiment, a preferred embodiment of the present invention was particularly described, but the V! The present invention is not limited to the above embodiment, and for example, the heat sealing agent does not necessarily need to be applied completely along the folding line 3 in a predetermined width. Any improvements or changes can be made without departing from the gist of the invention.

[Effects of the Invention] As described above, according to the manufacturing method of the wJ cut seal bag of the present invention, since the heat sealing agent is applied in advance around the folding line, when the plastic film is melted and cut by the heated blade, The vicinity of the folding line of the fusing seal portion is firmly adhered, and therefore a durable fusing seal bag is formed without peeling of the seal or opening of the seal in this area. Also, the fusing seal bag of the present invention! Since the PJ manufacturing method involves fusing and sealing, it is possible to manufacture even a single layer of heat-sealable resin film, and it has the excellent advantage of being able to form a sealed portion with virtually no width on both sides. .

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view showing the manufacturing process of one embodiment of the method for producing a fusing seal bag of the present invention, Fig. 2 is a plan view of an example of a fusing seal bag formed by the present invention, and Fig. 3 represents a sectional view taken along the line Δ-Δ in FIG. 2. 1...Plastic film 2...Heat sealing agent 3...Folding line 4...Fust-cut sealing part 5...Piece 1 Heshi 6...Heating blade adhesive part Patent applicant Toppan El+Stock Company Representative Patent Attorney Miyao Ichinose

Claims (1)

[Claims] In the method for manufacturing a melt-cut seal bag, a long stretched plastic film is folded from approximately the center in the width direction, cut with a heating blade at a predetermined interval in the longitudinal direction, and simultaneously welded the cut surfaces. A method for manufacturing a weld-sealed bag, characterized in that a heat sealing agent is applied along the periphery of the folding line.