JPH10157775A - Fumigating bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fumigating bag which allows fumigation as it is especially when the bag is used for garden stuff and allows freshness during a subsequent distribution process by preparing the bag with nonwoven cloth having specific water vapor permeability, water resistance, air permeability and tensile strength used as at least a part of the bag. SOLUTION: Air-permeable nonwoven cloth having water vapor pemeability of 3000 to 10000g/m<2> 24Hr, water resistance of 300 mm or higher, air permeability of l to 300 seconds and tensile strength of 9kg/3cm or more is used in at least a part to manufacture a bag for transporting garden stuff. The nonwoven cloth is manufactured by a melt-blow method wherein thermoplastic polymer is melted and extruded from a spinneret and dragged and thinned by a high speed air stream to capture as fiber with an average diameter of 10μm or less into a sheet. Since appropriate air permeability and water vapor permeability is thus obtained simultaneously as physical property of the nonwoven cloth, gas permeability and waterproofness for keeping freshness of the garden stuff can be satisfied simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fumigation bag having excellent gas permeability and waterproofness and having insect repellency.

[0002]

2. Description of the Related Art Conventionally, caskets, hemp bags, and the like have been used to transport fruits and vegetables. However, when vegetables and fruits are transported in these bags, freshness is rapidly increased because moisture evaporates too much through the voids in the bags. Has the disadvantage of being reduced. In addition, when rain or the like enters the bag, the bag gets wet with water, so that there is a drawback of the bag such as fruit and vegetables rotting.

[0003] Recently, fruits and vegetables are often transported in cardboard boxes, but also in this case, the freshness is drastically reduced. In this case, a thermoplastic resin film is used between the cardboard boxes and the fruits and vegetables to maintain freshness. ing. As the thermoplastic film, for example, a sheet made of polyethylene, polypropylene, polyester, polyamide, or a laminated / composite film thereof is often used. It is said that the use of these films makes it possible to prevent the diffusion of moisture and maintain freshness.

[0004] However, in some cases, various gases evaporate from the fruits and vegetables, and the gases themselves may reduce the freshness of the fruits and vegetables. In such a case, a film having small holes is used for the purpose of transmitting the gas. These films are called perforated films and the diameter of the holes is 0.5-3 mm
Most of them are used. When these films (both perforated and non-perforated) are used, since the fruits and vegetables are packaged with the films, the fruits and vegetables as the contents can be kept clean and fresh.

[0005] In recent years, fresh fruits and vegetables have not only been produced in Japan, but also imported from countries all over the world, and in particular, fresh fruits and vegetables, vegetables and fruits have been transported by air. Or they may be imported by sea from neighboring countries.In the case of these imports, they are required to undergo quarantine at the port or airport based on the Plant Protection Act at the time of entry into the country, and to disinfect by fumigation for those with pests. Have been.

However, when a film using a thermoplastic film is subjected to such a fumigation process, it is necessary to remove the film each time since the film does not transmit gas. Therefore, if fumigation is required at the time of import, remove the film once for fumigation,
It is necessary to perform fumigation and then refill the film or bag again to maintain freshness, which is complicated and
There is a drawback that freshness is reduced during refilling and / or fruit and vegetables are damaged due to handling. In the case of a perforated film, gas permeates through the small holes, so that if there are pores with a certain area ratio or more, gas sterilization is possible,
At the same time, there is a disadvantage that the freshness of fruits and vegetables is reduced. In this case, there is no suitable perforated area that simultaneously satisfies fumigation and prevention of freshness reduction, and either insufficient fumigation effect or reduced freshness of fruits and vegetables occurs. Therefore, in the case of using a perforated film, it is necessary to use a bag or cover made of a film or the like in order to maintain freshness after fumigation, which has been a problem.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a bag that can be fumigated, especially when used for fruits and vegetables.
It does not remove the freshness retaining film from the cardboard box each time during fumigation and can be sterilized as it is, and after fumigation, it has insect repellent and antibacterial properties while keeping freshness, so it has a form that can be distributed as it is, It is intended to provide a bag excellent in sterilization, preservation and freshness maintenance. That is, an object of the present invention is to provide a bag for transporting fruits and vegetables, which is more excellent in transport, sterilization, preservation, and freshness retention than in the case of cardboard and a thermoplastic film.
At the same time, the fumigation sterilization process required at the time of import is performed efficiently to save labor and reduce the cost of transportation and sterilization processes.

[0008]

Means for Solving the Problems The present inventors have found that by using bags having specific physical properties, the freshness of fruits and vegetables and the like can be maintained and the fumigation ability can be maintained as it is, and the superiority in distribution from producers to consumers can be obtained. It has been found that excellent handling properties can be obtained, and the present invention has been completed.

That is, according to the present invention, the moisture permeability is 3000-1.
0000 g / m ² · 24 Hr, water resistance 300 mm or more, air permeability 1 to 300 seconds, and tensile strength 9 kg / m
A non-woven fabric having air permeability and waterproofness of 3 cm or more (hereinafter referred to as a "permeable non-woven fabric") is used at least in part. When used for fruits and vegetables, freshness can be maintained in a state where fruits and vegetables are inserted. The present invention relates to a fumigation bag using at least a part of a gas-permeable nonwoven fabric which can be transported and fumigated.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The air permeable nonwoven fabric used in the present invention can be basically produced based on a nonwoven fabric by a melt blow method using a thermoplastic resin. Melt blow method is a method in which a thermoplastic polymer is melted, extruded from a spinneret, drawn and thinned by a high-speed gas stream to form fibers having an average diameter of 10 μm or less, and then collected and manufactured in a sheet shape. is there. In this case, the fiber diameter is smaller than that of a nonwoven fabric formed by a normal spunbonding method. The thermoplastic polymer used here is polyethylene,
Polyolefin such as polypropylene, polyester such as polyethylene terephthalate, nylon 6, nylon 6
6, polyamides such as nylon 610, polyvinyl alcohol-based polymers, vinyl chloride-based polymers, acrylic polymers and the like can be applied.

Since the sheet-like material after collection cannot be maintained as it is, it is necessary to provide some kind of reinforcement.
Usually, a thermoplastic spunbonded nonwoven fabric is placed along one or both sides, and the shape is maintained by integrating them.

The spunbonded nonwoven fabric used for reinforcement can be manufactured by a usual manufacturing method.
Approximately 40 g / m ² can be used. Generally, it is preferable that the same material as that manufactured by the melt blow method and that manufactured by the spun bond method be bonded by heat.

As a method of integration, a bonding method using a hot roll, a needle punching method, a water entanglement method, and the like can be used, but a hot bonding method using a hot roll is preferred because it is simple.

The nonwoven fabric formed by the ordinary melt blow method alone has a small fiber diameter and thus has excellent moisture permeability, but has a drawback that the tensile strength of the nonwoven fabric is not high, so that a secondary reinforcing material is required. As reinforcement, various net-like objects represented by, for example, knitted fabrics and warifs can be used in addition to lamination of nonwoven fabrics.

When the fumigation bag of the present invention is used for fruits and vegetables, it must have excellent gas permeability to pass through the fumigation step, and as a guide, it must have air permeability and moisture permeability. Also, in order for this material to have excellent freshness retention properties, it must not have excessive air permeability and moisture permeability.

In order to simultaneously satisfy the freshness maintenance and sterilization for fruits and vegetables, the bag material should have a moisture permeability of 3000-1.
In the present invention, 0000 g / m ² · 24 Hr and air permeability of 1 to 300 seconds are required. The moisture permeability is JIS L-1099
The measurement by the cup method is generally common, and the measurement condition is usually measured at 40 ° C.-90%. Air permeability is JI
It is usually measured by the Gurley method specified in SP-8117. In general, air permeability and moisture permeability are measures for gas permeability, and should normally be specified by the permeability of fumigation gas such as hydrocyanic acid gas or methyl bromide gas. It can be determined from data on general moisture permeability and air permeability.

The moisture permeability is 3000 to 10000 g / m ^2.
24Hr is required, preferably 4000-8000
g / m ² · 24Hr, air permeability is 1 to 300 seconds, preferably 5 to 200 seconds. Moisture permeability of 3000g / m ² · ²
If it is less than 4Hr, gas permeability represented by water vapor is inferior,
Therefore, the fumigation effect at the time of gas sterilization deteriorates. That is, it is not preferable because the fumigation time is lengthened or an incomplete fumigation effect is obtained. Moisture permeability of 1000g / m ² · 24
If it exceeds Hr, there is no problem as a gas sterilizing effect, but the freshness of the fruits and vegetables (mainly the water contained in the fruits and vegetables) is transmitted too much, and they are immediately dried up and the freshness is greatly reduced. In order to generate fine pores, it is necessary to add a large number of fine powders, for example, and the strength as an air-permeable film is lowered, which is not preferable in practical use.

The air permeability is preferably from 10 to 300.
The air permeability is measured and displayed as the time (seconds) required for general air to permeate a certain area. Generally, the larger the numerical value is, the more a certain volume of air passes. Since it is a necessary time, air permeability deteriorates. For normal woven fabrics, it is one second or less. Dough having good air permeability, that is, too low air permeability, is not preferable because the freshness of the fruits and vegetables is poor. If the air permeability exceeds 300 seconds, the air permeability deteriorates, and the fumigation effect decreases, which is not preferable. Therefore, in the case of the air-permeable nonwoven fabric according to the present invention, it is necessary to set the moisture permeability and the air permeability in an appropriate range, whereby it is possible to impart necessary freshness retention and fumigation possibility.

The fruits and vegetables mentioned here are particularly imported a lot, for example, banana, pineapple, orange, kiwi, grapefruit, lemon, lime, navel, prune,
Apricot, apricot, cherry, grape, peach, pear, plum, apple, chestnut, avocado, loquat, mango and other raw fruits, pumpkin, kinusa, rice, sweet corn, asparagus, broccoli, garlic, celery, ginger,
Potato is a general term for raw vegetables such as carrots, cabbage, and lettuce. These fruits and vegetables need to maintain freshness during transportation, and must be sterilized by fumigation (including insecticide).

As the gas used for fumigation, a commonly used cyanuric acid gas or methyl bromide gas can be used.

The bag of the material according to the present invention has a water pressure resistance of 300.
mm or more is required. Water resistance is usually JISL-1092
It can be measured by Method A. Generally, the larger the numerical value of the water pressure resistance, the better the waterproofness. In general spunbonded nonwoven fabrics, since the pores are large, the water pressure resistance is 100 mm or less. However, in this case, if the fruits or vegetables as the contents are brought into contact with water, decay is accelerated, which is of course undesirable.
If the water pressure resistance is less than 300 mm, for example, if it comes into contact with water for a long time, water infiltration occurs, which is not preferable. In the case of a composite nonwoven fabric based on a meltblown nonwoven fabric, the water pressure resistance is 30
If it is less than 0 mm, it is considered to have relatively large pores, and air permeability becomes too large, which is not preferable.

The air-permeable nonwoven fabric according to the present invention has a water resistance of 300 mm or more because of having fine pores made of ultrafine fibers, and has appropriate air permeability and moisture permeability simultaneously as physical properties of the nonwoven fabric. Gas permeability and water resistance for keeping freshness of the fruits and vegetables as a nonwoven fabric can be satisfied at the same time.

As a permeable nonwoven fabric material for fruits and vegetables, a tensile strength of 9 kg / 3 cm or more is required. The tensile strength is J
IS L-1096 6.12 Measure by the strip method.

The tensile strength specified in the present invention as a bag is
Necessary to prevent the bag from being damaged by fruits and vegetables during bag making, transportation, and fumigation. It is preferably at least 12 kg / 3 cm. If the tensile strength is 9 kg / 3 cm or less, the strength of the bag body is not sufficient, and the bag body is damaged due to the projections or partial impact of the fruits and vegetables as the contents, which is not preferable. When the tensile strength is, for example, 30 kg / 3 cm or more, there is no problem in the strength as a bag, but it is not preferable because the thickness of the nonwoven fabric for strengthening needs to be increased more than necessary.

Usually, in the case of a bag containing fruits and vegetables, a heat sealing method is generally used to make the bag at low cost. Air-permeable nonwoven fabrics can be made by heat sealing. A nonwoven fabric alone can be used for the bag making, but if bonding by heat sealing is used, a bag made of a combination of an air permeable nonwoven fabric and another film is preferable because the bag making is simple. In particular, it is preferable that the film combined with the air-permeable nonwoven fabric be combined with a composite film containing a material having a low melting point (comprising a low-melting material and a high-melting material). For example, as a low melting point material, E having a melting point of around 100 ° C.
Examples of VA-based materials and polyester materials having a melting point of about 260 ° C. as high melting point materials. When such a composite film is used, heat sealing with the nonwoven fabric can be performed relatively easily. As a method for heat sealing, a method using an ordinary heating bar or a method using an impulse sealer can be used.

As the shape of the bag, a general three-way heat seal or a gusset bag can be used, and after putting the fruits and vegetables, the remaining one is heat-sealed to produce a permeable nonwoven bag combined with a film. It becomes possible.

At the same time, by enclosing such fruits and vegetables in a bag made of air-permeable nonwoven fabric, secondary effects such as prevention of soiling of fruits and vegetables and maintenance of a clean state can be expected, which is preferable.

Further, it can be seen that the bag using the air permeable nonwoven fabric according to the present invention has excellent sealing properties by heat sealing, and thus exhibits a property of preventing small insects from entering.

The fumigation bag of the present invention can of course be used for other than fruits and vegetables.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments.

The evaluation in this embodiment is as follows.

Examples 1 and 2 described after "Freshness retention"
And a material used in Comparative Examples 1 to 4 and a low-density polyethylene film having a thickness of 100 μm were manufactured with a 25 cm square three-side seal (using an impulse sealer), and one grapefruit was put therein. Was heat-sealed to produce a test body. After storing this bag at room temperature for 10 days, it was opened, halved, and the freshness inside was visually determined. If there was no problem, A was designated as D, the dried state was designated as D, and the intermediate stage was designated as B or C.

[Gas Permeability] A test bag for checking freshness retention was put into an acrylic box of about 10 liters, and methyl bromide gas was introduced into the box at a rate of 30 mg / liter. Was taken out, and in order to measure the gas concentration in the bag, suction was performed with a syringe and the concentration was measured with a gas crographograph. Assuming that the concentration in the box is 100%, the gas concentration in the bag is 95% or more, A, 80 to 9
B was 5%, C was 50 to 80%, and D was less than 50%.

(Examples 1 and 2, Comparative Examples 1 to 4) A melt-blown air-permeable nonwoven fabric made of a polypropylene resin, a basis weight of 30 g / m ² and a polypropylene spunbonded nonwoven fabric,
A bag that is heat-sealed three-way with an impulse sealer using a permeable nonwoven fabric produced by laminating a basis weight of 20 g / m ² and joining with a hot embossing roll, and a 100-μm-thick film made of low-density polyethylene. (Dimensions about 25c
m square). A melt blow sheet using polyethylene terephthalate resin in Example 2 with a basis weight of 40 g /
used as a m ^2, and an example of using the spunbonded nonwoven fabric made of the same material, the basis weight 25 g / m ² obtained by thermal bonding. Comparative Example 1 is a general polypropylene spunbond nonwoven fabric, an example having a thickness of 200 μm, Comparative Example 2 is a low-density polyethylene film, Comparative Example 3 is a low-density polyethylene 1 in which holes having a diameter of about 1 mm are formed at 10 mm intervals in the vertical and horizontal directions.
The case where a 00 μm film is used is shown.

Grapefruit was placed in these bags, and the change in freshness and the permeability of fumigated gas with methyl bromide were evaluated. In the bag according to the present invention, the freshness did not decrease even after 10 days from the encapsulation, and it was confirmed that the gas due to methyl bromide was sufficiently permeated, and that both fumigation and freshness retention could be achieved. In Comparative Example 1, the freshness retention was good, but the gas permeability was poor and the fumigation effect was not obtained. In Comparative Example 2, similarly, the freshness retention was good, but the gas permeability was quite poor, and no fumigation effect was obtained. Further, the porous film having zero water pressure resistance shown in Comparative Example 3 does not show preferable gas permeability despite showing the same moisture permeability and air permeability as the present invention,
No fumigation effect has been obtained.

The effectiveness of the present invention is apparent from the above points.

[0037]

[Table 1]

[0038]

The bag using the gas permeable nonwoven fabric according to the present invention has excellent gas permeability, waterproofness and insect repellency, and therefore exhibits excellent performance as a bag for fumigation.

That is, sterilization can be carried out without removing the freshness retaining film from the cardboard box at the time of fumigation, and after fumigation, the freshness can be maintained and the freshness can be maintained. Have, transport
A bag excellent in sterilization, preservation, and freshness maintenance can be provided.

Claims (1)

[Claims] 1. A water vapor transmission rate of 3000 to 10000 g / m ^2.
・ 24Hr, water resistance 300mm or more, air permeability 1-3
A bag for fumigation, characterized by using at least a part of a nonwoven fabric having air permeability and waterproofness having a tensile strength of 9 kg / 3 cm or more for 00 seconds.