JPH09221148A - Packaging sack for grain - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation in strength of a packaging sack and provide excellent deaerating performance and vermin preventing property, in a grain packaging sack formed of a plastic film having deaerating pores. SOLUTION: A packaging sack is formed by adhering with heat plastic single layers or multilayer laminate films into a shape of sack. In a grain packaging sack 10, a plurality of holes having pore size of 100-1000μm are formed at end areas 3a, 3b, 4a, 4b of the packaging sacks which are not blocked by the superposed packaging sacks when grains are put therein and superposed, at an interval of 5-10mm between the holes. In forming the holes, a heating needle is used. In addition, when the film is of a multilayer laminate film, a laser beam irradiation method is preferable from the viewpoint that holes having stable pore sizes can be formed with excellent productivity.

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to packaging rice grains,
Regarding the packaging bag used for distribution, more specifically, when the rice grains are enclosed and stacked in the packaging bag, an opening portion is provided to allow excess air remaining inside to escape and prevent bag breakage. The technology of packaging bags for rice grains.

[0002]

2. Description of the Related Art Conventionally, a packaging bag used for packaging and distributing rice grains is usually a packaging bag produced by heat-bonding a plastic multilayer laminated film or a single layer film into a bag shape. Has been. As the film forming the bag, for example, a biaxially stretched nylon film /
A multilayer laminated film such as an aluminum-deposited polyethylene terephthalate film / linear low-density polyethylene layer laminated film, a biaxially stretched nylon film / linear low-density polyethylene layer laminated film, or a linear low-density polyethylene monolayer. Layer films and the like are used.

[0003] When filling and packaging rice grains in a packaging bag formed of such a film, a vertical filling and packaging machine is usually used. When top sealing is performed after filling, as much air as possible is left in the head space. As described above, a method of mechanically pressing a jig such as sponge rubber from both sides to perform deaeration packaging is adopted. However, when the content is rice grains, it is a heavy weight, and when the packed packages after encapsulation are stacked and piled up, a large load is applied to the lower package, so the above deaeration is not sufficient. However, there is a problem that the internal pressure rises due to the remaining air, which causes bag breakage. Therefore, in the packaging bag,
Further, to release excess air that remains, a hole diameter of 1-2 m
Measures are taken such as providing an appropriate number of m holes or notches having a length of about 2 mm, or sticking a non-woven tape to a part of the back seal portion when the bag is a pillow type.

[0004]

In the above-mentioned prior art, for example, when a hole having a hole diameter of 1 to 2 mm is provided in a packaging bag, it is large enough to allow excess air in the bag to escape, The number of holes to be opened per bag may be small, and the decrease in bag strength due to this is not a problem. However, if the hole diameter is 1
In the case of ˜2 mm, there was a problem that harmful insects such as kouzo, kouzo elephant, etc. invaded from the openings to eat the contents such as rice. Also, when making a notch with a length of about 2 mm,
The cut tends to be large due to tearing from the notch, and when it becomes large, problems of insect damage and spilling of the contents occur as in the above case. And, in the method of pasting the non-woven tape on the spine seal part, the usual deaeration is excellent, but when the contents are actually filled and packed and accumulated and piled up, the tape pasted part is crushed. Therefore, the deaeration property of the air remaining in the bag is reduced. Further, in the case of this form, the number of members is increased, and the degree of processing such as attachment thereof is increased, so that there is also a drawback that the cost is high.

The present invention has been made in view of the above problems, and an object thereof is to provide a plastic film packaging bag for rice grains made of a plastic film having a plurality of holes for deaeration. , The degassing performance of the opening is effectively exhibited without being impaired in actual use, and the problem of the strength of the bag is not reduced due to the opening.
An object of the present invention is to provide a packaging bag for rice grains, which is excellent in the ability to prevent invasion of harmful insects such as elephant elephant, with high productivity.

[0006]

[Means for Solving the Problems] As a result of intensive research to solve the above problems, as a result, in order to prevent the invasion of harmful insects such as foxtail and foxtail, the diameter of the holes provided in the packaging bag (if the holes are not circular, the maximum diameter is Diameter) of 1000 μm or less. The number of holes is preferably such that when the packages with the contents enclosed are stacked, it can be quickly degassed so as not to cause bag breakage due to the internal pressure of the air remaining inside. Need to be opened. Also,
In order to minimize the reduction in strength of the packaging bag due to the opening of holes and to obtain good deaeration, it is sufficient to keep the distance between the holes within the range of 5 to 10 mm and to secure the necessary number of holes. Furthermore, regarding the position where the holes are made, when the packages enclosing the contents are stacked, the packages overlap each other,
Since the degassing effect is impaired at the position where the hole is blocked, it was found that it is effective to provide it near the edge where it is difficult to contact the adjacent packaging body, and based on this, under various conditions The present invention has been completed by repeating and studying an experiment in which a predetermined amount of contents are actually enclosed in a packaging bag having a predetermined size and an opening is provided and the contents are stacked on a pallet.

That is, the invention described in claim 1 is a packaging bag formed by heat-bonding a film mainly made of plastic in a bag shape, and the packaging bag has a plurality of holes having a hole diameter of 100 to 1000 μm. And a packaging bag for rice grains. Further, the invention according to claim 2 is an area of an end portion of the packaging bag in which the plurality of holes of the packaging bag are not blocked by the stacked packaging bags when the rice grains are enclosed and stacked in the packaging bag. The packaging bag for rice grains according to claim 1, wherein the packaging bag is for rice grains. Further, the invention according to claim 3 is characterized in that the film of the packaging bag is a multilayer laminated film, and the plurality of holes of the packaging bag are holes opened by irradiation of laser light. The packaging bag for rice grains according to claim 1 or 2.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the rice cereal packaging bag of the present invention will be described below. The film used for the packaging bag for rice grains of the present invention is basically not particularly limited, and any single-layer or multilayer laminated film of plastic conventionally used for packaging bags for rice grains can be used. it can. Specifically, as described above, in the multilayer laminated film, biaxially stretched nylon film / adhesive layer / aluminum deposited biaxially stretched polyethylene terephthalate film / adhesive layer / linear low-density polyethylene layer, biaxially stretched nylon film / adhesive A laminated film such as layer / linear low-density polyethylene layer is often used, and a single-layer film such as linear low-density polyethylene can also be used. (Hereinafter, the biaxially stretched nylon film is abbreviated as ON, the biaxially stretched polyethylene terephthalate film is abbreviated as PET, and the linear low-density polyethylene is abbreviated as LLDPE.)

In the above, dry laminating method or extrusion laminating method using an adhesive resin can be used for laminating films such as ON and aluminum vapor-deposited PET, and aluminum vapor-deposited PET or LLDPE layer on the ON surface can be formed. For lamination, film-shaped LLDPE may be laminated by a dry lamination method, or LLDPE resin may be extrusion-coated to laminate. In addition, the aluminum vapor deposition having the above structure may be omitted if unnecessary. When the aluminum vapor-deposited layer is not required as described above, not only the constitution but also all the layers may be formed into a laminated film by a multi-layer co-extrusion method. A tube having a predetermined folding diameter may be directly formed by inflation molding to form a tube (bottom seal) type packaging bag.

The rice grain packaging bag of the present invention remains in the bag when rice grains are packed, accumulated and stacked in a packaging bag produced by heat-bonding these films into a bag shape. To prevent the bag from rupturing due to a sudden increase in the internal pressure caused by air, holes are provided at the specified positions, at the specified size and at the required intervals, to allow the internal air to escape to the outside (degassing). The feature is that these will be described below.

First, in the packaging bag of the present invention, the form of the bag that can be used is not particularly limited. For example, a three-sided seal type, a pillow type, or an inflation type, which has been mainly used in conventional packaging bags for rice grains. Any form such as a molded tube (bottom seal) type can be used. And
The position of the deaeration hole provided in the packaging bag is usually because after stacking the contents in the packaging bag and stacking the bags by stacking them up and down, in this state, the packaging bodies adjacent to each other vertically, horizontally, etc. It is preferable that the holes are provided, for example, on the side surfaces (curved surfaces) of both end portions of the bag so as not to block the provided holes.

Specifically, the size of the end portion (side surface) of the bag varies depending on the size of the bag and the filling amount of the contents, so it is difficult to uniformly specify a numerical value, but for example, the size 340.
When 10 kg of rice is packed in a bag of mm (width) x 570 mm (length), and in a pillow type or tube type packaging bag, an area in the range of 5 mm to 40 mm from the left and right ends, and three sides With a seal type packaging bag, 5 mm to 40 mm from both ends excluding the left and right seal margins
It is preferable to provide holes in a region within a certain range. Similarly, when 5 kg of rice is enclosed in a bag having a size of 280 mm (width) x 470 mm (length), and a size of 220 mm
When 2 kg of rice is enclosed in a bag of (width) × 350 mm (length), it is preferable to provide holes in a region of about 5 mm to 30 mm from the left and right ends.

The size of the holes provided in the packaging bag is preferably large so that the air in the bag can be quickly degassed. However, if it is too large, inconveniences such as invasion of pests, spillage of contents, and deterioration of bag strength will occur, and in particular, from the viewpoint of preventing invasion of pests, the upper limit of the pore diameter (when the holes are not circular, the maximum diameter) is It is preferably 1000 μm or less. And although the lower limit of the pore size is not as strict as the upper limit,
If it is too small, the degassing rate will decrease, so that it is necessary to increase the number of holes, and accordingly, the distance between the holes also decreases. As a result, the bag strength is reduced and the workability of the opening is also reduced. Therefore, the lower limit of pore size is 100μ
It is preferably about m. For the above reasons, the holes provided in the packaging bag preferably have a hole diameter of 100 to 1000 μm, more preferably 150 to 300 μm.

Regarding the space between the holes, for example, if the number of holes is increased in order to improve the deaerating property, it is necessary to reduce the space, and if the space is too small, the strength of the packaging bag decreases. To do. Further, if the interval is increased, there is no problem in terms of strength, but the number of holes is reduced, and in order to obtain the necessary degassing property, it is necessary to increase the diameter of the holes, and the diameter of the holes is too large ( As described above, there is a problem of pest invasion. Therefore, it is preferable that the distance between the holes is also adjusted within a certain range, and specifically, the range of 5 mm to 10 mm is preferable. If the distance between the holes is less than 5mm, the weight of the contents is 5k
Although there is no problem in strength up to g, when the weight is 10 kg, the strength becomes insufficient and the spaces between the holes are torn due to a drop impact or the like, which causes bag breakage. Further, when the distance between the holes is more than 10 mm, there is no problem of strength reduction and it is not as strict as the lower limit, but the number of holes per bag is small, and in some cases, holes having a diameter of 1000 μm or more are required. However, it is not preferable because it allows the invasion of pests. Note that the relationship between the hole spacing and the hole diameter may be within the range that satisfies the above conditions, and is not particularly limited.

In the method of forming the holes as described above, when the hole diameter is as large as 1 to 2 mm as in the conventional product, the hole can be opened by the ordinary punching method, but the hole diameter is 100 to 1000 μm as in the present invention. When it is small, a method using a heating needle or the like can be preferably applied. If the amount of contents filled in the packaging bag is as large as 5 kg or 10 kg,
It is necessary to increase the strength of the bag, and in most cases, a multilayer laminated film as described above is used. When the packaging bag is thus formed of a multilayer laminated film including layers such as nylon and polyethylene terephthalate, a method of irradiating laser light can be more preferably applied as a method of forming holes.

The laser irradiation of the pulse oscillation type is used for perforating the laminated film with the above laser beam, but if the laser is capable of on / off control in the order of microseconds, it is intermittent in the form of spots, notches, etc. Drilling is possible. A carbon dioxide gas laser, a YAG laser, a semiconductor laser, an argon ion laser, or the like can be used as the type of laser, and there is no particular limitation, but in order to make a hole in the film, the film absorbs the laser oscillation wavelength and generates heat. However, it is necessary to form a mist, and from this point, a carbon dioxide gas laser can be particularly preferably used.

The wavelength of carbon dioxide laser light is 10.6 μm
Many films such as nylon, polyethylene terephthalate, and polypropylene, which are widely used as packaging materials, can absorb this and generate heat, but can be opened.
A low-density polyethylene film cannot be perforated because it is hardly absorbed and penetrates. However, when low-density polyethylene is laminated with a film that absorbs carbon dioxide gas laser light as described above and is used as a laminated film, the carbon dioxide laser light should be output adjusted and irradiated on the laminated film. As a result, the layer that absorbs this heat is generated, and the heat can simultaneously open the low density polyethylene layer. By using such a laser beam as a means for making a hole, the hole diameter is from several tens of μm to 1 μm.
Even a small hole of 000 μm has an advantage that it can be opened with a stable hole diameter and high productivity, and that the hole diameter and the hole interval can be easily changed.

[0018]

The present invention will be described in more detail below with reference to the drawings and examples. However, the present invention is not limited to these. FIG. 1 is a schematic plan view for explaining the structure of an embodiment of the rice grain packaging bag of the present invention. The packaging bag 10 for rice grains shown in FIG. 1 shows an example of a pillow type packaging bag used for filling and packaging rice and distributing it. Usually, a roll-shaped laminated film is pulled out and heated. Alternatively, by irradiating with laser light, a plurality of holes for deaeration are formed within the areas shown as preferable hole forming areas 3a, 3b, 4a, and 4b, and the hole diameter (diameter of the maximum portion) is 100 to 1000 μm.
m, with a hole interval of 5 to 10 mm, provided along the flow direction of the laminated film, then folded back so that the bag has a predetermined width on both left and right sides with the sealant layer of the laminated film as the inside At both ends, the back seal portion 1 is formed into a tubular body by heat-bonding in a palm-sealed form, and the back seal portion is laid down to be flat, and the bottom seal portion 2 is formed at a predetermined pitch in the flow direction. Are heat-bonded to each other, and a portion immediately behind the bottom seal portion 2 is cut to form individual packaging bags. The dimensions of the packaging bag shown in FIG. 1 are shown as an example in the case of filling and packaging 10 kg of rice. For reference, the standard dimensions of the rice packaging bag are shown below. For 10 kg 340 mm (width) x 570 mm For 5 kg 280 mm (width) x 470 mm For 2 kg 220 mm (width) x 350 mm

The present invention will be specifically described below with reference to examples. First, a pillow-type packaging bag for filling and packaging 10 kg of rice is made of a laminated film and has a thickness of 15 μm.
m biaxially stretched nylon film and a linear low-density polyethylene film having a thickness of 60 μm are pasted together by a known dry lamination method using a two-component reactive urethane adhesive to form a 700 mm-width roll-shaped laminate. I made a film. In order to provide a plurality of holes for degassing in the laminated film, a carbon dioxide gas laser was used to remove 2.5c from the left and right ends of the film on both upper and lower sides of the packaging bag after bag making.
After a total of four rows of holes were provided at the inner side of the m along the flow direction of the laminated film at the hole diameters and the hole intervals shown in Examples 1 to 7 of Table 1, the holes were formed at the folding diameter (of the bag). Width) 340 mm,
Back seal width 10 mm, bottom seal width 10 mm, total bag length 5
The bag was made to have a size of 70 mm, and each of Examples 1 to 7
I made a packaging bag. The total number of holes (average value per bag) of the packaging bags of each example is as shown in Table 1.
Further, as a reference example, Table 1 also shows the state of punching a commercially available conventional type rice bag for 10 kg.

[0020]

[Table 1]

[Evaluation and Results] Each of the packaging bags of Examples 1 to 7 and the reference example having the openings as shown in Table 1 was used as a sample, and its deaeration, bag strength, and insect invasion were prevented. The sex was evaluated, and the results are summarized in Table 2. The number of samples was 10 each.

(1) Deaeration test Time (seconds) until 12 L of air is filled in each packaging bag and a 5 kg load is applied to complete deaeration.
Was measured. The evaluation of this test was a relative evaluation based on the reference example. (Symbol) (Evaluation Criteria) ◎: Degassing is faster than the packaging bag (58 seconds) of the reference example. ◯: Same as the packaging bag of the reference example (58 seconds) to +10 seconds (68 seconds in total). Δ: Packaging bag of Reference Example from +11 seconds (69 seconds in total) to +30 seconds (88 seconds in total). (Even at this level, there are no problems such as bag breakage in the drop test and stacking test, and there is no problem in practice.) ×: Degassing slower than 31 seconds than the packaging bag (58 seconds) of the reference example (total 89 seconds or more) Such things).

(2) Strength test of packaging bag (a) Drop test Each packaging bag of each sample is filled with 10 kg of rice and 1 m
From the height of the bag, the bag was dropped vertically, horizontally, and sideways three times, and the presence or absence of a bag was examined.

(B) Stacking test Each packaging bag of each sample was filled with 10 kg of rice, 10 pieces were stacked on a pallet, transported to a warehouse, stored for 3 days, taken out and examined for the presence of broken bags. .

(3) Prevention of insect invasion With respect to the prevention of insect invasion, even the packaging bag provided with holes of 2 mmφ in the reference example is easy because the number of holes is as small as 8 in a packaging bag containing 10 kg. Although it does not invade, it is not preferable because insect invasion is observed in a long-term test of 1 month or more. On the other hand, in the packaging bags of Examples 1 to 7, the number of holes was large, but the hole diameter itself was as small as 1000 μm or less, so that invasion of insects was not recognized and it was good. (Below margin)

[0026]

[Table 2] Evaluation results

[0027]

As described above in detail, according to the present invention, the strength of the bag is not impaired, and the contents such as rice remain in the bag when they are packed, accumulated and stacked. The effect that the excess air can be smoothly discharged to the outside, the bag is not broken due to the increase of the internal pressure, and the pests can be prevented from invading, and the rice grain packaging bag having excellent performance can be easily provided. Further, the packaging bag is made of a plastic laminated film, and the holes for deaeration are opened by irradiation with laser light, so that even if the hole diameter is a small hole of several 10 μm to 1000 μm, a hole having a stable hole diameter is formed. Can be opened with high productivity, and it is easy to change the hole diameter and hole spacing, so it can easily accommodate different size packaging bags, and it is possible to improve the productivity of rice grain packaging bags with excellent productivity. There is an effect that can be provided.

[Brief description of drawings]

FIG. 1 is a schematic plan view illustrating a form of an embodiment of a packaging bag for rice grains of the present invention.

[Explanation of symbols]

1 Back seal part 2 Bottom seal part 3a, 3b, 4a, 4b Preferable perforation area 10 Rice grain packaging bag

Claims (3)

[Claims] 1. A packaging bag formed by heat-bonding a plastic-based film in a bag shape, the packaging bag having a hole diameter of 10
A packaging bag for rice grains, which has a plurality of holes of 0 to 1000 μm. 2. A plurality of holes of the packaging bag are provided in an area of an end portion of the packaging bag which is not blocked by the stacked packaging bags when rice grains are enclosed and stacked in the packaging bag. The packaging bag for rice grains according to claim 1. 3. The film of the packaging bag is a multilayer laminated film, and the plurality of holes of the packaging bag are holes opened by irradiation of laser light. The packaging bag for rice grains described in.