JP2000219250A - Bag body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bag body which has excellent openability and reduces the mistaken feed of bags during the automatic filling and packaging. SOLUTION: A bag body P in which at least the innermost layer is formed of a thermoplastic resin and which is formed of a packaging material having a metallic foil layer in an intermediate layer, an uneven part A machined by the laser beam is provided on the innermost layer at least on one side of an inner side of an opening part to be finally sealed through the heat seal. Stable openability can be provided without giving any special additive, and the mistaken feed of bags can be reduced during the automatic bag feeding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bag for storing various articles such as foods, and more particularly, to a bag for automatically filling and packaging contents.

[0002]

2. Description of the Related Art Generally, in an automatic filling process of contents into a bag, the vicinity of the upper part of the supplied bag is pulled from both sides with a suction octopus to make the mouth open, the contents are charged, and the opening is opened. It is performed by sealing with heat sealing. Therefore, when automatically filling and packaging the contents, the suitability of the bag to be supplied and the opening property are important factors directly linked to workability and yield. Therefore, means for improving the opening property of the bag body has been conventionally employed.
It is common to add an anti-blocking agent (hereinafter referred to as an AB agent) or a slip agent (hereinafter referred to as an SL agent), or to improve the opening property of the opening of the bag body by dusting during lamination or bag making. It is.

[0003]

SUMMARY OF THE INVENTION A described in the prior art
As the B agent, silica, zeolite, talc and the like are used, but when these are added, various physical properties (transparency, bag strength, heat sealability, etc.) of the bag are deteriorated, and there is a problem of kosuri. There is a problem that scratches are generated in the bag, and the increase in cost due to the addition of the AB agent is also a major problem.

[0004] On the other hand, fatty acid amides and the like used as SL agents are powdery on the inner surface of the bag to provide openness. However, the balance of addition is difficult, and if the amount is small, poor openness. If the amount is large, the problem of dusting occurs. Further, since the powder becomes powdery on the inner surface of the bag, the heat sealability may be impaired. Further, since the temperature sensitivity is high, the slip property may change due to seasonal temperature fluctuation. Further, when additives such as an antistatic agent and an anti-don agent are used in the bag, their effects may be hindered. In addition, since it is powdery on the surface, it has a drawback that it cannot be used for dusty contents such as precision electronic members. Naturally, the increase in cost due to addition is also a major problem.

[0005] Dusting powder is a particle of about 10 µm made from starch granules, and imparts openness and slipperiness by being scattered on the surface during lamination or bag making. The balance is difficult, and if the amount is small, the opening property is poor, and if the amount is large, the problem of dusting occurs. Further, since powder is used in the laminating step and the bag making step, there is a problem that the working environment of the factory is significantly deteriorated. In addition, since it is powdery on the surface, it has a drawback that it cannot be used for dusty contents such as precision electronic members, foods and pharmaceuticals that require high hygiene, and the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a bag which has a good opening property and reduces bag supply errors during automatic filling and packaging. To provide.

[0007]

In order to solve the above-mentioned problem, the present invention provides irregularities on at least one surface corresponding to the opening of the bag. And by such unevenness | corrugation, a stable opening property can be provided to a bag body without performing special additive prescription.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is directed to a bag comprising a packaging material having at least an innermost layer formed of a thermoplastic resin and having a metal foil layer in an intermediate layer. At least one side of the inner surface of the opening to be sealed is provided with unevenness by laser processing on the innermost layer.

As the thermoplastic resin used as the material for forming the innermost layer, polyolefin, polyamide, polyester and the like can be mentioned, and polyolefin is particularly preferable. As the metal foil layer as the intermediate layer, an aluminum foil is generally used, but other metal foils such as an alloy foil having an increased iron content can also be used.

The laser processing applied to the packaging material may be performed in any of a film forming step, a laminating step, and a bag making step. However, when the packaging material is wound up after the laser processing, the laser processing is performed. Usually, it is preferably carried out at the time of bag-making because the material cannot be wound neatly due to the projections and the positioning is difficult.

FIG. 1 shows the cross-sectional shape of the unevenness by laser processing.
It seems as shown. In FIG. 1, reference numeral 1 denotes a metal foil layer as an intermediate layer, 2 denotes an innermost layer made of a thermoplastic resin, and unevenness A by laser processing is formed on the innermost layer 2. The height a of the convex portion in the unevenness A is 0.5 μm.
The thickness is preferably less than 500 μm. If the height of the projection is less than 0.5 μm, the effect of laser processing cannot be obtained. In addition, a projection having a height of 500 μm or more is formed,
If a strong treatment is applied to layers other than the sealant layer, the strength of the packaging material is degraded, and the appearance of the bag-made product is deteriorated.

The position where the irregularities are formed by performing the laser processing is within a range of about 1 to 40 mm from the opening end, and is finally a position that is sealed by heat sealing and does not come into contact with the contents. This is because if laser processing is performed on a portion that is in direct contact with the contents, adverse effects are exhibited in terms of physical properties, hygiene, and easy opening.

The unevenness by the laser processing may be provided in an appropriate pattern within a range of about 1 to 40 mm from the end of the opening. The shape of the pattern is not particularly limited, but the unevenness may be linear or dotted. Therefore, it is preferable to provide at least one row in parallel with the opening end. FIG.
Shows an example of a bag body P provided with three rows of linear irregularities A parallel to the opening end, and FIG. 3 shows a bag body provided with three rows of dotted irregularities A parallel to the opening end. An example of P is shown.

[0014]

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Example 1) By dry lamination, PET (12 μm) / DL / Al (7 μm) / DL
A laminated film having a layer configuration of / CPP (70 μm) was obtained. No additives such as an AB agent and an SL agent were added to the CPP (unstretched polypropylene) layer, which is the innermost layer forming material, and no dusting was performed during lamination. And, the size of the bag is 140 × 170 mm outside dimensions,
A seal width was set to 8 mm, and at the time of bag making, one linear unevenness was formed on one surface of the film by laser processing so that the distance from the opening end was 4 mm and parallel to the opening end. Specifically, a carbon dioxide gas laser irradiator having an oscillation wavelength of 10.6 μm (“48-1-28” manufactured by Shinrad Co., Ltd.)
W ") using a 5w output and a bag making speed of 40 m / min.
Laser irradiation was performed in accordance with. The height of the formed protrusion was 3 μm.

Example 2 A bag of the same size was made with the same laminate film as in Example 1, but at the time of bag making, the distance from the opening end was 4 mm and parallel to the opening end. As described above, one dotted line unevenness was formed on one side of the film by laser processing. The laser irradiator used was the same as that in Example 1, and the laser irradiation was performed in a pulsed state at an output of 5 w at a bag making speed of 40 m / min. The height of the formed protrusion was 4 μm.

(Comparative Example 1) PET (12 μm) / DL / Al (7 μm) / DL by dry lamination
A laminated film having a layer configuration of / CPP (70 μm) was obtained. For the CPP layer, a material to which an AB agent was added was used. And the size of the bag is 140 × 170m
m and the seal width were set to 8 mm, and bag making was performed without performing laser processing.

(Comparative Example 2) By dry lamination, PET (12 μm) / DL / Al (7 μm) / DL
A laminated film having a layer configuration of / CPP (70 μm) was obtained. No additives such as AB agent and SL agent were added to the CPP layer, but dusting was performed during lamination. And, the size of the bag is 140 × 170 mm outside dimensions,
The seal width was set to 8 mm, and bag making was performed without performing laser processing.

Comparative Example 3 Bag making was performed in the same manner as in Example 1 except that the distance from the opening end of the linear unevenness formed by laser processing was 60 mm.

Comparative Example 4 Bag making was carried out in the same manner as in Example 1 except that the output of the carbon dioxide laser irradiation machine was changed to 2 watts. The height of the obtained protrusion was 0.4 μm.

(Experiment 1) Using an automatic bag filling and filling machine ("TT8C" manufactured by Toyo Automatic Machinery Co., Ltd.), water 100 at 35 bags / min.
A test for filling cc was carried out in each of the 3,000 bags in each section, and the frequency of bag supply failure and opening failure was measured. Table 1 shows the obtained results.

[0022]

[Table 1]

From the test results, the bags of Example 1, Example 2, Comparative Example 2 and Comparative Example 3 were good in frequency of both poor bag supply and poor opening, but the bag of Comparative Example 1 was good. Many bag defects occurred. In the bags of Comparative Examples 3 and 4, poor opening occurred.

(Experiment 2) Bags of Example 1, Example 2 and Comparative Example 2 were filled with 100 cc of the IPA solution purged with fine particles in a clean room and sealed. This IP
The number of fine particles of 4 μm or more contained in the solution A was measured by a liquid particle counter, and converted into the number of fine particles per area of the inner surface of the pouch.

[0025]

[Table 2]

From the results shown in Table 2, the bag of Comparative Example 2 has many particles on the inner surface.
It is clear that the bag body is preferable.

[0027]

As described above, the bag of the present invention is
By providing irregularities by laser processing on at least one side of the inner surface of the opening finally sealed by heat sealing, a stable opening property can be imparted without performing a special additive prescription, and automatic bag supply mistakes can be prevented. Can be reduced.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a cross-sectional shape of unevenness by laser processing.

FIG. 2 is a perspective view of a main part showing an example of a bag body in which three rows of linear irregularities are provided in parallel with an opening end.

FIG. 3 is a perspective view of a main part showing an example of a bag body in which three dotted lines of irregularities are provided in parallel with an opening end.

[Explanation of symbols]

 1 Metal foil layer 2 Innermost layer A Irregularity P Bag

Claims (4)

[Claims] An inner surface of an opening portion which is formed of a packaging material having at least an innermost layer formed of a thermoplastic resin and having a metal foil layer in an intermediate layer, and which is finally sealed by heat sealing. Characterized in that the innermost layer is provided with irregularities by laser processing on at least one side of the bag. 2. The bag according to claim 1, wherein the height of the projections in the unevenness is 0.5 μm or more and less than 500 μm. 3. The bag according to claim 1, wherein the unevenness is linear, and is provided in at least one row in parallel with the opening end. 4. The bag according to claim 1, wherein the unevenness is dotted and is provided in at least one row in parallel with the opening end.