WO2011034038A1

WO2011034038A1 - Packaging bag and production method thereof

Info

Publication number: WO2011034038A1
Application number: PCT/JP2010/065784
Authority: WO
Inventors: 佳孝國定; 稔一田中; 秀穂岩田; 晴男西村
Original assignee: 萩原工業株式会社
Priority date: 2009-09-15
Filing date: 2010-09-14
Publication date: 2011-03-24
Also published as: JP2012236607A

Abstract

A packaging bag (11) comprises a cylindrical mesh (5) and a pair of bands (6), wherein the cylindrical mesh (5) is woven using uniaxially-stretched tapes as warps and wefts, intersections of the warps and wefts are thermally adhered, the uniaxially-stretched tape is composed of at least three thermoplastic layers, the melting point of the thermoplastic resin constituting the inner layer is lower than the melting point of the thermoplastic resin constituting the outer layer, the bands (6) are made of a thermoplastic resin, the cylindrical mesh (5) is arranged between the pair of bands (6), surfaces of the cylindrical mesh (5) and the pair of bands (6) are thermally adhered, and the cylindrical mesh (5) and the pair of bands (6) are thermally adhered and closed at the bottom (7) of the packaging bag (11). Thereby, provided is a packaging bag which has favorable air permeability, can prevent damage to agricultural crops, etc., such as vegetables, fruits, and bulbs when such agricultural crops, etc., are filled in the bag, has a low weight, and is superior in strength and a shape retention property, and also provided is a production method of the packaging bag.

Description

Packaging bag and manufacturing method thereof

The present invention relates to a packaging bag suitable for filling agricultural products and the like and a method for manufacturing the same.

A packaging bag made of plastic net is known as a bag for packaging crops such as vegetables, fruits and bulbs. Such a packaging bag made of plastic net cannot print information such as contents and manufacturer on the packaging bag, so it is necessary to put a label on the plastic net, but the label is peeled off in the distribution process etc. There was a problem. As a method for solving this problem, a packaging bag in which a film on which information such as contents and manufacturer is printed is bonded to a plastic net is known.

In Patent Document 1, a cylindrical mesh made of a heat-bondable plastic material is disposed between two opposed bands, and the cylindrical mesh and two opposed bands are thermally bonded in the vertical direction. A packaging bag filled with a product in which a mesh mesh and two opposed bands are thermally bonded at the bottom and top of the packaging bag and closed. According to this, it is said that it can withstand the pressure applied to the packaging bag when transporting products such as fruits and vegetables. However, it is not always possible to prevent the products such as fruits and vegetables filled in the packaging bag from being damaged, and improvement has been desired.

Further, in Patent Document 2, a cylindrical mesh or net made of a heat-bondable plastic material is disposed between a pair of bands, and the cylindrical mesh and the pair of bands are thermally bonded to each other. A flexible container for wrapping products such as fruits and vegetables, in which a pair of bands is thermally bonded and closed at the bottom of the flexible container is described. According to this, the tear resistance is high and the air permeability of the product is also good. However, it is not always possible to prevent the products such as fruits and vegetables filled in the packaging bag from being damaged, and improvement has been desired.

EP1176104A2 US4403637A

The present invention has been made to solve the above problems, has good air permeability, can prevent crops from being damaged when filled with crops such as vegetables, fruits, bulbs, etc. Provided are a packaging bag having a small weight and excellent strength and form retention and a method for producing the same.

The above problem is a packaging bag comprising a cylindrical mesh and a pair of bands, and the cylindrical mesh is woven using a uniaxially stretched tape as a warp and the intersection of the warp and weft is thermally bonded, The uniaxially stretched tape is composed of at least three thermoplastic resin layers, the melting point of the thermoplastic resin constituting the outer layer is lower than the melting point of the thermoplastic resin constituting the inner layer, the band is made of the thermoplastic resin, and has a cylindrical shape. The mesh is disposed between the pair of bands, the surface of the cylindrical mesh and the pair of bands are thermally bonded, and the cylindrical mesh and the pair of bands are thermally bonded and closed at the bottom of the packaging bag. It is solved by providing a packaging bag characterized in that.

At this time, it is preferable that the cylindrical mesh and the pair of bands are thermally bonded so that the uniaxially stretched tape constituting the cylindrical mesh is arranged in both the vertical direction and the horizontal direction in the packaging bag, The weight per unit area of the cylindrical mesh is preferably 10 to 20 g / m ² . The thickness of the uniaxially stretched tape is preferably 15 to 40 μm, and the width of the uniaxially stretched tape used for the warp is preferably 0.6 to 1.4 mm. The width of the uniaxially stretched tape used for the weft is preferably larger than the width of the uniaxially stretched tape used for the warp, and the tensile strength per unit weight of 1 g / m ^{2 of} the cylindrical mesh is 7. It is preferable that it is 5 N / 5 cm or more.

At this time, the coverage of the cylindrical mesh represented by the following formula (1) is preferably 40 to 70%.
Coverage (%) = 100 − [{(25.4− (A × B)) × (25.4− (C × D)) / (25.4 × 25.4)} × 100] (1)
A: Width of uniaxially stretched tape used for warp (mm)
B: Woven density of uniaxially stretched tape used for warp (main / 25.4mm)
C: Width of uniaxially stretched tape used for weft (mm)
D: Woven density of uniaxially stretched tape used for weft (2 / 25.4mm)

Further, at this time, it is preferable that the intersection ratio represented by the following formula (2) of the cylindrical mesh is 5 to 20%.
Intersection ratio (%) = {(A × B) × (C × D) / (25.4 × 25.4)} × 100 (2)
A: Width of uniaxially stretched tape used for warp (mm)
B: Woven density of uniaxially stretched tape used for warp (main / 25.4mm)
C: Width of uniaxially stretched tape used for weft (mm)
D: Woven density of uniaxially stretched tape used for weft (2 / 25.4mm)

At this time, the woven density of the uniaxially stretched tape in the vertical direction of the portion where the surface of the cylindrical mesh and the pair of bands are thermally bonded is the woven density of the uniaxially stretched tape in the vertical direction of the portion not thermally bonded. The crop packaging body in which the agricultural products are packed in the packaging bag of the present invention is a preferred embodiment of the present invention.

A method for manufacturing a packaging bag comprising a cylindrical mesh and a pair of bands is obtained by folding the mesh along the longitudinal direction to obtain a cylindrical mesh, and winding the cylindrical mesh to obtain a cylindrical mesh roll. After that, it is a preferred embodiment of the present invention to provide a method for manufacturing a packaging bag, characterized in that the surface of the cylindrical mesh supplied from the roll is thermally bonded to the pair of bands.

At this time, after thermally bonding the surface of the cylindrical mesh and the pair of bands, it is preferable to form a gusset along the longitudinal direction of the cylindrical mesh, and when folding the mesh along the longitudinal direction It is preferable to obtain a cylindrical mesh roll after folding the mesh so that both ends do not overlap each other. Further, at this time, when the mesh is folded along the longitudinal direction, it is preferable to fold the mesh so that both ends overlap each other and wind up while shifting the portion where both ends overlap each other to obtain a cylindrical mesh roll. .

Moreover, at this time, it is a method for producing an agricultural product package in which agricultural products are filled in a packaging bag composed of a cylindrical mesh and a pair of bands, and the cylindrical mesh is obtained by folding the mesh along the longitudinal direction. After winding the cylindrical mesh to obtain a cylindrical mesh roll, the surface of the cylindrical mesh supplied from the roll and a pair of bands are thermally bonded to form a packaging bag, and the crop is obtained in the resulting packaging bag. It is also a preferred embodiment of the present invention to provide a method for producing an agricultural product package, which is characterized in that the opening of the packaging bag is closed by heat welding after filling.

In addition, the above-mentioned problem is a cylindrical mesh roll formed by folding and winding a mesh, and the mesh is woven using a uniaxially stretched tape as a warp and the intersection of the warp and weft is thermally bonded. The uniaxially stretched tape is composed of at least three thermoplastic resin layers, and the melting point of the thermoplastic resin constituting the outer layer is lower than the melting point of the thermoplastic resin constituting the inner layer, so that both ends of the mesh do not overlap each other. The problem can also be solved by providing a cylindrical mesh roll in which the mesh is folded along the longitudinal direction and wound.

According to the present invention, air permeability is good, and when crops such as vegetables, fruits, bulbs, etc. are filled, the crops can be prevented from being damaged, the weight per unit area is small, and the strength and shape retention are excellent. A packaging bag and a method for manufacturing the same are provided.

1 is a front view of a package obtained in Example 1. FIG. 1 is a side view of a package obtained in Example 1. FIG. 1 is a view showing a cylindrical mesh roll obtained in Example 1. FIG. In Example 1, it is the figure which has arrange | positioned the cylindrical mesh between a pair of bands. In Example 1, it is the figure which showed the cylindrical body obtained by heat-bonding a cylindrical mesh and a pair of band. In Example 1, it is the figure which showed the cylindrical body in which the gusset was formed. 1 is a view showing a packaging bag obtained in Example 1. FIG. FIG. 2 is a cross-sectional view of the package obtained in Example 1 along AA. It is a figure which shows an example of the manufacturing process of the packaging bag of this invention.

The packaging bag of the present invention is a packaging bag comprising a cylindrical mesh and a pair of bands, and the cylindrical mesh is woven using a uniaxially stretched tape as the warp and the intersection of the warp and weft is thermally bonded. The uniaxially stretched tape comprises at least three thermoplastic resin layers, the melting point of the thermoplastic resin constituting the outer layer is lower than the melting point of the thermoplastic resin constituting the inner layer, and the band comprises the thermoplastic resin. The cylindrical mesh is disposed between the pair of bands, the surface of the cylindrical mesh and the pair of bands are thermally bonded, and the cylindrical mesh and the pair of bands are thermally bonded at the bottom of the packaging bag. It is characterized by being closed. As described above, the packaging bag of the present invention has a cylindrical mesh woven using the uniaxially stretched tape as the warp and the intersections of the warp and weft are thermally bonded. It is possible to prevent the crops and the like from being damaged when they are filled. In addition, a packaging body obtained by filling agricultural products, etc. is provided with a packaging bag excellent in form retention because the mesh does not stretch and the agricultural products are not collected at the bottom of the packaging body even when standing. Can do.

The cylindrical mesh constituting the packaging bag of the present invention is woven using uniaxially stretched tape as warp and weft. Here, the uniaxially stretched tape used in the present invention comprises at least three thermoplastic resin layers, and the melting point of the thermoplastic resin constituting the outer layer is lower than the melting point of the thermoplastic resin constituting the inner layer. That is, the uniaxially stretched tape used in the present invention is composed of at least three thermoplastic resin layers, and both surfaces of the inner layer made of a thermoplastic resin having a relatively high melting point are outer layers made of a thermoplastic resin having a relatively low melting point. It is covered with.

The MFR (melt flow rate; 190 ° C., 2.16 kg load) of the thermoplastic resin having a relatively high melting point used for the inner layer of the uniaxially stretched tape is not particularly limited and may be 0.1 to 10 g / 10 min. preferable. Specific examples of the thermoplastic resin having a relatively high melting point include polyolefin, polyester, polyamide and the like. Among them, polyolefin is preferably used from the viewpoint of low specific gravity and good processability. Examples of polyolefin include high-density polyethylene, polypropylene, propylene-ethylene block copolymer, propylene-ethylene random copolymer, and the like. From the viewpoint of excellent stretchability and high strength, high density can be obtained. Polyethylene and polypropylene are preferably used.

Further, the MFR (melt flow rate; 190 ° C., 2.16 kg load) of the thermoplastic resin having a relatively low melting point used for the outer layer of the uniaxially stretched tape is not particularly limited, and is 0.5 to 10 g / 10 minutes. It is preferable. The thermoplastic resin having a relatively low melting point is not particularly limited as long as it is a thermoplastic resin having a lower melting point than the thermoplastic resin having a relatively high melting point constituting the inner layer, and includes polyolefin, polyester, polyamide and the like. When the resin used for the inner layer is a polyolefin, the adhesion between the inner layer and the outer layer is good, and delamination between the inner and outer layers hardly occurs. From such a viewpoint, polyolefin is preferably used as the thermoplastic resin having a relatively low melting point. The thermoplastic resin having a relatively low melting point is preferably a thermoplastic resin having a melting point of 5 ° C. or more lower than that of a thermoplastic resin having a relatively high melting point, and more preferably a thermoplastic resin having a melting point of 10 ° C. or more. preferable. Specifically, linear low-density polyethylene (including ethylene / α-olefin copolymer produced using metallocene catalyst), low-density polyethylene, ethylene-vinyl acetate copolymer, propylene-ethylene random copolymer Examples thereof include linear low-density polyethylene and low-density polyethylene.

There are no particular limitations on the combination of the layer configurations of the uniaxially stretched tape, for example, linear low density polyethylene layer / high density polyethylene layer / linear low density polyethylene layer, low density polyethylene layer / high density polyethylene layer / low density. Examples thereof include a polyethylene layer, a propylene-ethylene random copolymer layer / a polypropylene homopolymer layer / a propylene-ethylene random copolymer layer. Among them, from the viewpoint of flexibility, a uniaxial structure composed of a linear low density polyethylene layer / high density polyethylene layer / linear low density polyethylene layer, or a low density polyethylene layer / high density polyethylene layer / low density polyethylene layer. A stretched tape is preferably used.

The cross-sectional area ratio (both outer layer / inner layer) between the inner layer and both outer layers in the uniaxially stretched tape is preferably 1/9 to 6/4. When the cross-sectional area ratio is less than 1/9, the adhesion between the cylindrical mesh and the pair of bands may be insufficient, and the cross-sectional area ratio is more preferably 2/8 or more. On the other hand, when the cross-sectional area ratio exceeds 6/4, the tensile strength of the uniaxially stretched tape may be remarkably reduced in the step of thermally bonding the intersections of the mesh described later, and is more preferably 5/5 or less. Here, the cross-sectional area of both outer layers in the above-mentioned cross-sectional area ratio is the sum of the cross-sectional areas of the outer layers covering both surfaces of the inner layer.

The uniaxially stretched tape used in the present invention is obtained by, for example, obtaining a film by an T-die method or an inflation method using an extruder, slitting the obtained film, performing a stretching treatment, and then performing a relaxation heat treatment. It is preferably manufactured. At this time, the draw ratio is preferably 3 to 12 times. When the draw ratio is less than 3 times, the mechanical strength may be insufficient, and it is more preferably 4 times or more. On the other hand, when the draw ratio exceeds 12 times, the tape may be cut or torn easily at the time of drawing, and the workability may be lowered, and it is more preferably 10 times or less. As the stretching treatment, a heating method such as a hot plate type, a hot roll type, an infrared type, or a hot air type can be employed. The stretching temperature is appropriately set according to the resin used. By performing the stretching treatment in this way, a uniaxially stretched tape having physical properties of a tensile strength of 3.0 to 7.0 cN / dt (centinewton / dtex) and a tensile elongation of 15 to 35% can be obtained. .

The thickness of the uniaxially stretched tape used in the present invention is not particularly limited and is preferably 15 to 40 μm. When thickness is less than 15 micrometers, there exists a possibility that the intensity | strength of the cylindrical mesh obtained may fall, and it is more preferable that it is 20 micrometers or more. On the other hand, if the thickness exceeds 40 μm, the surface of the resulting cylindrical mesh will be uneven, and there is a risk that wrinkles will occur when the surface of the cylindrical mesh is thermally bonded to the pair of bands, which is 35 μm or less. It is more preferable that

The width of the uniaxially stretched tape used in the present invention is not particularly limited, and the width of the uniaxially stretched tape used for the warp is preferably 0.6 to 1.4 mm. When the width of the uniaxially stretched tape used for the warp is less than 0.6 mm, the strength of the cylindrical mesh in the vertical direction of the packaging bag is reduced and the adhesiveness between the surface of the cylindrical mesh and the pair of bands is insufficient. It is more likely that the thickness is 0.8 mm or more. On the other hand, when the width of the uniaxially stretched tape used for the warp exceeds 1.4 mm, the intersection ratio of the cylindrical mesh may increase, and the flexibility of the packaging bag may be impaired, and the width is 1.3 mm or less. Is more preferable.

Further, the width of the uniaxially stretched tape used for the weft is not particularly limited and is preferably 1.0 to 1.8 mm. When the width of the uniaxially stretched tape used for the weft is less than 1.0 mm, the strength of the cylindrical mesh in the horizontal direction of the packaging bag may be reduced, and is preferably 1.2 mm or more. On the other hand, when the width of the uniaxially stretched tape used for the weft exceeds 1.8 mm, the intersection ratio of the cylindrical mesh may increase, and the flexibility of the packaging bag may be impaired, and is 1.6 mm or less. Is more preferable.

Here, in the packaging bag of the present invention, the cylindrical mesh is disposed between the pair of bands, and the surface of the cylindrical mesh and the pair of bands are thermally bonded, so the load in the vertical direction of the mesh is small. It has become. On the other hand, on the side surface of the packaging bag, the mesh is not covered with the film constituting the band, and when the packaging bag is filled with agricultural products or the like, the load on the mesh in the horizontal direction becomes large. Therefore, from the viewpoint of increasing the strength of the cylindrical mesh in the horizontal direction, it is a preferred embodiment of the present invention that the width of the uniaxially stretched tape used for the weft is larger than the width of the uniaxially stretched tape used for the warp. .

The fineness of the uniaxially stretched tape used in the present invention is not particularly limited, and is preferably 50 to 800 dt (decitex). When the fineness is less than 50 dt, the durability may be reduced, and is preferably 100 dt or more, and more preferably 200 dt or more. On the other hand, when the fineness exceeds 800 dt, the flexibility of the resulting cylindrical mesh may be impaired, more preferably 700 dt or less, and still more preferably 600 dt or less.

The mesh can be produced by weaving the above-described uniaxially stretched tape as a warp and thermally bonding the intersections of the warp and weft. The mesh weaving method is not particularly limited, but it can be finished flat so as not to damage the crops packed in the packaging bag, and the viewpoint that makes it difficult to distract even if the bond at the intersection is peeled off Therefore, a plain weave is preferable. In addition, the mesh used in the present invention is obtained by heat-bonding the intersections of the warp and weft yarns, thereby obtaining a mesh that is prevented from being opened and eyes are difficult to open. The method for thermally bonding the intersections of the warp and weft is not particularly limited, and is preferably performed by a hot plate contact method, a heat roll method, an infrared irradiation method, or the like. At this time, it is preferable to perform thermal bonding at a temperature lower than the melting point of the thermoplastic resin constituting the inner layer of the uniaxially stretched tape and equal to or higher than the melting point of the thermoplastic resin constituting both outer layers.

The cylindrical mesh used in the present invention is not particularly limited as long as the mesh is made into a cylindrical shape, and may be a cylindrical mesh in which both ends of the mesh do not overlap each other. A cylindrical mesh formed by overlapping and heat-welding both ends may be used. However, when the packaging bag of the present invention is filled with crops or the like, a load is applied to the cylindrical mesh disposed on the side surface of the packaging bag, so the cylindrical mesh used in the present invention is disposed on the side surface of the packaging bag. It is important that the mesh being made is a continuous mesh. When producing a cylindrical mesh roll to be described later, a cylindrical mesh in which both ends of the mesh are not overlapped from the viewpoint that the winding diameter can be increased and a cylindrical mesh of a certain length or more can be taken up. Are preferably used.

The woven density in the cylindrical mesh used in the present invention is not particularly limited, and the woven density of the uniaxially stretched tape used for the warp is preferably 4 to 10 pieces / 2.54 cm. When the weave density is less than 4 / 2.54 cm, the strength of the cylindrical mesh is insufficient, and the adhesion between the surface of the cylindrical mesh and the pair of bands may be insufficient. More preferably, it is 54 cm or more. On the other hand, when the weave density exceeds 10 pieces / 2.54 cm, the cost may increase, and it is more preferably 9 pieces / 2.54 cm or less. In addition, from the viewpoint of reducing costs and securing the wefts more reliably, in the cylindrical mesh used in the present invention, the weave of the uniaxially stretched tape used for the warp is higher than the woven density of the uniaxially stretched tape used for the weft. It is preferable to increase the density.

The basis weight of the cylindrical mesh used in the present invention is not particularly limited, and is preferably 10 to 20 g / m ² . When the weight per unit area of the cylindrical mesh is less than 10 g / m ² , there is a risk that sufficient strength may not be obtained when filling agricultural products or handling the filled package, and the weight is 12 g / m ² or more. Is more preferably 14 g / m ² or more. On the other hand, when the weight per unit area of the cylindrical mesh exceeds 20 g / m ² , there is a possibility that the discarded amount of the packaging bag after use may increase, and it is more preferably 18 g / m ² or less, and 15 g / m ^2. More preferably, it is as follows.

The cylindrical mesh used in the present invention is woven with a uniaxially stretched tape in which the warp and weft are highly stretched, and the tensile strength per unit weight of 1 g / m ² is 7.5 N / 5 cm or more. Preferably there is. Thus, the tensile strength of the packaging bag obtained even if the basis weight of the cylindrical mesh is reduced is kept above a certain level by the tensile strength of the cylindrical mesh per unit weight of 1 g / m ² being above a certain level. Can do. The tensile strength of the cylindrical mesh per unit weight of 1 g / m ² is more preferably 8.5 N / 5 cm or more, and further preferably 9.5 N / 5 cm or more. Further, the tensile strength of the cylindrical mesh per unit weight 1 g / m ² is usually 50 N / 5 cm or less.

In addition, the tensile elongation of the cylindrical mesh used in the present invention is not particularly limited, and the tensile elongation is preferably 10 to 40% in both circumstances. If the tensile elongation is less than 10%, the cylindrical mesh may be cut by impact when filling the packaging bags with crops or dropping the packaging, and it is 15% or more. Is more preferable. On the other hand, when the tensile elongation exceeds 40%, the form retainability of the package filled with agricultural products or the like may be impaired, and it is more preferably 35% or less.

Further, the coverage represented by the following formula (1) of the cylindrical mesh used in the present invention is preferably 40 to 70%. When the coverage is within this range, a cylindrical mesh having good air permeability, high strength and excellent flexibility can be obtained, and the adhesiveness between the surface of the cylindrical mesh and a pair of bands can be obtained. It becomes good. When the coverage of the cylindrical mesh is less than 40%, the strength of the cylindrical mesh decreases, and the adhesion between the surface of the cylindrical mesh and the pair of bands may be insufficient, and is 45% or more. It is more preferable. On the other hand, when the coverage exceeds 70%, the flexibility of the cylindrical mesh may be impaired, and it is more preferably 60% or less.
Coverage (%) = 100 − [{(25.4− (A × B)) × (25.4− (C × D)) / (25.4 × 25.4)} × 100] (1)
A: Width of uniaxially stretched tape used for warp (mm)
B: Woven density of uniaxially stretched tape used for warp (main / 25.4mm)
C: Width of uniaxially stretched tape used for weft (mm)
D: Woven density of uniaxially stretched tape used for weft (2 / 25.4mm)

Further, the intersection ratio represented by the following formula (2) of the cylindrical mesh used in the present invention is preferably 5 to 20%. When the intersection ratio is in this range, a cylindrical mesh having excellent flexibility can be obtained, and damage to crops and the like can be prevented. When the intersection ratio is less than 5%, the intersection may be easily peeled off and the eyes may be easily displaced, and is more preferably 8% or more. On the other hand, when the intersection ratio exceeds 20%, the flexibility of the cylindrical mesh may be impaired, and it is more preferably 15% or less.
Intersection ratio (%) = {(A × B) × (C × D) / (25.4 × 25.4)} × 100 (2)
A: Width of uniaxially stretched tape used for warp (mm)
B: Woven density of uniaxially stretched tape used for warp (main / 25.4mm)
C: Width of uniaxially stretched tape used for weft (mm)
D: Woven density of uniaxially stretched tape used for weft (2 / 25.4mm)

The pair of bands in the packaging bag of the present invention is not particularly limited as long as it is a film made of a thermoplastic resin that can be thermally bonded to the surface of the cylindrical mesh. Specific examples of the thermoplastic resin include polyolefin, polyester, polyamide, and the like. Among them, polyolefin is preferably used from the viewpoint of low specific gravity and excellent processability. Polyolefins include high-density polyethylene, low-density polyethylene, linear low-density polyethylene (including ethylene / α-olefin copolymers produced using metallocene catalysts), polypropylene, and ethylene-vinyl acetate copolymers. , Propylene-ethylene block copolymers, propylene-ethylene random copolymers, and the like. Among them, low density polyethylene, linear low density polyethylene, and polypropylene are preferably used.

In addition, the film made of the thermoplastic resin constituting the pair of bands may be a single layer or a multilayer, but adhesion and durability when the surface of the cylindrical mesh and the film are thermally bonded. In consideration of the above, it is preferable that the pair of bands is a multilayer film. At this time, the preferred layer structure of the multilayer film is that the inner layer, which is an adhesive layer with the cylindrical mesh, is made of a thermoplastic resin having a relatively low melting point and good thermal adhesiveness with the cylindrical mesh, and the outer layer is It is a layer structure made of a thermoplastic resin having a relatively high melting point. The layer structure (outer layer / inner layer) of such a multilayer film is not particularly limited, and examples include polypropylene / low density polyethylene, polyester / low density polyethylene, polyamide / low density polyethylene, high density polyethylene / low density polyethylene, Among them, a two-layer film made of polypropylene / low density polyethylene is preferably used. In the present invention, it is preferable that the film made of the thermoplastic resin constituting the pair of bands is printed with information such as the crop filled in the packaging bag and information such as the manufacturer. Etc., the distinguishability, traceability, etc. of the package filled with etc. become good.

As above, the cylindrical mesh and the pair of bands used in the present invention have been described. Hereinafter, the packaging bag of the present invention comprising a cylindrical mesh and a pair of bands and a method for producing the same will be described with reference to the drawings. In the packaging bag 11 of the present invention, the cylindrical mesh 5 is disposed between the pair of bands 6, and the surface of the cylindrical mesh 5 and the pair of bands 6 are thermally bonded. The band 6 is heat-bonded at the bottom 7 of the packaging bag 11 and is closed.

When the cylindrical mesh 5 used in the present invention is disposed between the pair of bands 6, the cylindrical mesh roll 8 is rolled out by winding the mesh in advance, whereby the cylindrical mesh 5 is moved to the pair of bands 6. 6 may be arranged between the pair of bands 6 after the mesh is folded in the bag making apparatus to produce the cylindrical mesh 5. It may be an embodiment. From the viewpoint that the packaging bag 11 of the present invention can be manufactured without attaching such means separately to an existing bag making apparatus that does not have means for folding the mesh to produce the cylindrical mesh 5. The embodiment which arrange | positions the cylindrical mesh 5 between a pair of bands 6 by paying out the mesh mesh roll 8 is employ | adopted suitably.

The cylindrical mesh roll 8 used in the present invention is not particularly limited as long as it is a roll formed by winding the cylindrical mesh 5, and when the mesh is folded along the longitudinal direction, both ends of the mesh are It may be a cylindrical mesh roll 8 that is folded and wound so as not to overlap, and when the mesh is folded along the longitudinal direction, it is folded and wound so that both ends of the mesh overlap each other. A cylindrical mesh roll 8 may be used. Here, folding the mesh along the longitudinal direction means that the mesh is folded in three along the longitudinal direction, that is, the both ends of the mesh are diffracted twice in total for each time. When the cylindrical mesh roll 8 is produced and folded so that both ends of the mesh overlap each other, the portion where the both ends of the mesh overlap each other swells, so that the cylindrical mesh of a certain length or more 5 may be difficult to wind up. From such a viewpoint, as shown in FIG. 3, when the mesh is folded along the longitudinal direction, a cylindrical mesh roll 8 that is folded and wound so that both ends of the mesh do not overlap each other is preferably used. It is done.

In the cylindrical mesh roll 8 that is folded and wound so that both ends of the mesh do not overlap each other, the interval between the both ends of the mesh is not particularly limited, and is preferably 1 mm or more and preferably 5 mm or more. Is more preferable. On the other hand, the distance between both ends of the mesh is usually 100 mm or less.

The cylindrical mesh roll 8 that is folded and wound so that both ends of the mesh do not overlap each other is preferably produced by winding the mesh through a folding guide, as can be seen from the examples described later. Is done. On the other hand, in a state in which both ends of the mesh are simply overlapped or in a state in which the overlapped ends are thermally welded, the cylindrical mesh roll 8 that is folded and wound so that the ends overlap each other is simply the cylindrical mesh 5. Although it may be produced by winding, as can be seen from the examples described later, from the viewpoint of suppressing the swelling of the portion where the both ends of the mesh overlap each other, the winding is performed while shifting the portion where the both ends of the mesh overlap each other. Thus, a method of obtaining the cylindrical mesh roll 8 is preferably employed.

In the packaging bag 11 of the present invention, the cylindrical mesh 5 is disposed between the pair of bands 6, and then the surface of the cylindrical mesh 5 and the pair of bands 6 are thermally bonded. Specifically, as shown in FIG. 4, a cylindrical mesh 5 that is folded so that both ends of the mesh do not overlap each other is disposed between a pair of bands 6, and then as shown in FIG. An embodiment in which the surface of the cylindrical mesh 5 and the longitudinal end portions 9 of the pair of bands 6 are thermally bonded to obtain the cylindrical body 10 is suitably employed. Here, as a preferred embodiment of the cylindrical body 10 obtained by thermally bonding the cylindrical mesh 5 and the pair of bands 6, a cylindrical shape is formed so that both ends of a continuous mesh do not overlap each other. A cylindrical body 10 obtained by thermally bonding the obtained cylindrical mesh 5 and a pair of bands 6, or a cylindrical mesh 5 obtained by heat-welding the two ends of one continuous mesh overlapped with each other. Examples thereof include a cylindrical body 10 obtained by thermally bonding the band 6. Among these, a cylindrical body 10 obtained by thermally bonding a cylindrical mesh 5 obtained by making a cylindrical shape and a pair of bands 6 so that both ends of one continuous mesh do not overlap each other is more preferably used. Alternatively, the cylindrical body 10 may be formed using two or more meshes.

Further, in the packaging bag 11 of the present invention, the woven density of the uniaxially stretched tape in the vertical direction of the portion where the surface of the cylindrical mesh 5 and the pair of bands 6 are thermally bonded is the vertical direction in the portion not thermally bonded. It is preferable that it is larger than the woven density of the uniaxially stretched tape. Thereby, the adhesive strength of the part formed by thermally bonding the surface of the cylindrical mesh 5 and the pair of bands 6 can be improved. Specifically, the woven density of the uniaxially stretched tape in the vertical direction of the thermally bonded portion is 1 / 2.54 cm or more higher than the woven density of the uniaxially stretched tape in the vertical direction of the portion not thermally bonded. It is preferable that 2 pieces / 2.54 cm or more is more preferable.

The method of thermally bonding the surface of the cylindrical mesh 5 and the pair of bunts 6 is not particularly limited, and a hot plate, a hot roll, hot air, or the like can be used, but a hot plate is used from the viewpoint of good productivity. The thermal bonding method used is preferably employed. At this time, the cylindrical mesh 5 and the pair of bands 6 may be thermally bonded so that the uniaxially stretched tape constituting the cylindrical mesh 5 is arranged in both the vertical direction and the horizontal direction in the packaging bag 11. preferable. Here, when the packaging bag 11 is filled with agricultural products or the like, the load in the horizontal direction and the vertical direction of the obtained packaging body 1 is increased, but the highly uniaxially stretched tape as described above is in the packaging bag 11. By being arranged in both the vertical direction and the horizontal direction, it is possible to obtain the package 1 having excellent shape retention without tearing or unnecessarily extending. Moreover, since the elasticity in the diagonal direction of the cylindrical mesh 5 is maintained, it has the advantage that the wrinkles of the packaging bag 11 are not conspicuous.

In the present invention, it is preferable to form a gusset along the longitudinal direction of the cylindrical mesh 5 after the surface of the cylindrical mesh 5 and the pair of bands 6 are thermally bonded. Thus, by forming a gusset, it has the advantage that the packaging bag 11 can be folded compactly. Specifically, in the cylindrical body 10 shown in FIG. 5, the cylindrical mesh 5 portion is cylindrical so that the cylindrical mesh 5 portion protruding from between the pair of bands 6 enters between the pair of bands 6. As shown in FIG. 6, an embodiment in which the tubular body 10 in which a gusset is formed is obtained by being folded toward the inside of the tubular body 10 is suitably employed.

The packaging bag 11 of the present invention is formed by thermally bonding the cylindrical mesh 5 and the pair of bands 6 at the bottom 7 of the packaging bag 11. Specifically, as shown in FIG. 7, the cylindrical mesh 5 and the pair of bands 6 are thermally bonded at the bottom 7 of the packaging bag 11 to form the packaging bag 11 of the present invention. As described above, the method for manufacturing the packaging bag 11 of the present invention has been described in order. Moreover, the packaging bag 11 of this invention can be suitably manufactured by a manufacturing process as shown in FIG. Hereinafter, a description will be given with reference to FIG. First, the cylindrical mesh 5 is fed out from the cylindrical mesh roll 8, and the cylindrical mesh 5 is supplied so as to wrap the cylinder 15 via the roller 12. At the same time, the pair of bands 6 are supplied from the roller 13 and the roller 14, and the cylindrical mesh 5 is disposed between the pair of bands 6. The surface of the cylindrical mesh 5 and the longitudinal end portions 9 of the pair of bands 6 are thermally bonded by the sealer 15 to obtain the cylindrical body 10, and the gusset is formed in the cylindrical body 10 through the gusset forming guide 17. It is formed. The cylindrical mesh 5 and the pair of bands 6 are thermally bonded at the bottom portion 7 of the packaging bag 11 by the sealer 18, and then cut in the horizontal direction by the cutter 19, whereby the packaging bag 11 can be obtained.

The packaging bag 11 of the present invention thus obtained has good air permeability and can prevent the crops from being damaged when the crops are filled. Since the packaging body 1 obtained by filling the packaging bag 11 with agricultural products etc. does not collect crops etc. in the lower part of the packaging body 1 even if it stands upright, the packaging bag is excellent in form retainability. 11 can be provided. Furthermore, the packaging bag 11 of the present invention can keep the tensile strength of the packaging bag 11 obtained even if the weight per unit area of the cylindrical mesh 5 is reduced to a certain level or less, and reduces the amount of discarded packaging bag 11 after use. It is also possible.

The package 1 filled with agricultural products or the like can be obtained by filling the packaging bags 11 of the present invention with agricultural products or the like and then heat-sealing and closing the openings of the packaging bags 11. As will be understood from the fact that two portions of the packaging bag 11 are 15 mm lower and 65 mm lower than the upper end 3 in the embodiment to be described later, a portion below a certain distance from the upper end 3 of the packaging bag 11 in the horizontal direction. It is preferable to heat-weld. Moreover, the embodiment which heat-welds the handle | steering-wheel 2 together is also employ | adopted suitably, and the agricultural product package 1 of this invention shown by FIG.1 and FIG.2 can be obtained.

As described above, the packaging bag 11 of the present invention has good air permeability, can prevent the crops and the like from being damaged when the crops and the like are filled, has a small weight per unit area, and has a strength and a shape retaining property. Is excellent. Therefore, it is suitable for the packaging bag 11 filled with agricultural products such as vegetables, fruits and bulbs, and particularly suitable for the packaging bag 11 filled with agricultural products such as fresh vegetables and fruits.

Hereinafter, the present invention will be described more specifically using examples.

Example 1
[Production of uniaxially stretched tape]
High density polyethylene (MFR 0.8 g / 10 min (190 ° C., 2.16 kg load), melting point 131 ° C., density 0.95 g / cm ³ ) on the inner layer, low density polyethylene (MFR 3.0 g / 10 min (190 ° C., A three-layer coextrusion blown film having a layer ratio of 1: 8: 1 in which a load of 2.16 kg), a melting point of 114 ° C., and a density of 0.92 g / cm ³ ) was arranged was produced. Subsequently, the film is slit into a narrow width and stretched at a draw ratio of 7 times using a hot plate stretching machine, and further subjected to a relaxation heat treatment with a relaxation rate of 6% on the hot plate, thereby obtaining a thread width of 1.2 mm. A uniaxially stretched tape consisting of three layers for warp having a yarn thickness of 29 μm and a fineness of 330 dt, and a uniaxially stretched tape consisting of three layers for weft having a yarn width of 1.5 mm, a yarn thickness of 23 μm and a fineness of 330 dt were obtained.

[Measurement of tensile strength and tensile elongation per unit fineness of uniaxially stretched tape]
According to JIS L1013 method, the obtained uniaxially stretched tape was set in a tensile tester with a gripping interval of 300 mm, and the stress and elongation when stretched at 23 ° C. until breaking at a rate of 300 mm / min. It was measured. The stress value when the maximum stress was shown was taken as the tensile strength, and the elongation until breaking was taken as the tensile elongation. The tensile strength per unit fineness (cN / dt) and the tensile elongation (%) were calculated by the following equations. The obtained results are summarized in Table 1.
Tensile strength per unit fineness (cN / dt) = [tensile strength (N) / fineness of uniaxially stretched tape (dt)] × 100
Tensile elongation (%) = [(Length after elongation−Initial length) / (Initial length)] × 100

[Mesh preparation]
Each uniaxially stretched tape obtained was woven into a plain weave with a slewer loom, and then heat-pressed at a hot plate temperature of 125 ° C. using a hot plate to thermally weld the intersections of the warp and weft, A mesh having 6 warps / 2.54 cm, 5 wefts / 2.54 cm, and a weight per unit area of 14.7 g / m ² was obtained.

[Measurement of tensile strength and tensile elongation of mesh]
Prepare a test piece with a mesh width of 50 mm and a length of 300 mm. Set the test piece in a tensile tester with a gripping interval of 200 mm according to JIS L1096 A method cut strip method, and at 23 ° C., 200 mm / min. The stress and the elongation were measured when the film was stretched until breaking at a rate of. The stress value when the maximum stress was shown was taken as the tensile strength, and the elongation until breaking was taken as the tensile elongation. The tensile elongation (%) was calculated by the following formula. The obtained results are summarized in Table 1. In addition, the present inventors have confirmed that there was no difference between the tensile strength and tensile elongation values of the mesh and the tensile strength and tensile elongation values of the cylindrical mesh.
Tensile elongation (%) = [(Length after elongation−Initial length) / (Initial length)] × 100

[Measurement of mesh coverage and intersection ratio]
When the coverage and intersection ratio of the mesh obtained above were calculated by the following equations, the coverage was 49.5% and the intersection ratio was 8.4%.
Coverage (%) = 100 − [{(25.4− (A × B)) × (25.4− (C × D)) / (25.4 × 25.4)} × 100] (1)
Intersection ratio (%) = {(A × B) × (C × D) / (25.4 × 25.4)} × 100 (2)
A: Width of uniaxially stretched tape used for warp (mm)
B: Woven density of uniaxially stretched tape used for warp (main / 25.4mm)
C: Width of uniaxially stretched tape used for weft (mm)
D: Woven density of uniaxially stretched tape used for weft (2 / 25.4mm)

[Production of cylindrical mesh roll]
The obtained mesh was cut into a width of 590 mm, and then wound through the folding guide while folding both ends toward the center by 145 mm, thereby obtaining a cylindrical mesh roll 8 having a width of 300 mm.

[Production of packaging bags]
Two rolls of a two-layer film (commercial product) made of polypropylene / low-density polyethylene having a thickness of 85 μm and a width of 117 mm constituting the band 6 were prepared. The cylindrical mesh roll 8 and the two-layer film roll were fed out, and the cylindrical mesh 5 was arranged between the pair of bands 6 so that the low-density polyethylene surface of the two-layer film was in contact with the surface of the cylindrical mesh 5. In order to prevent the cylindrical meshes 5 from being thermally bonded to each other, a total of four locations of the surface of the cylindrical mesh 5 and the longitudinal end portions 9 of the pair of bands 6 are welded with a welding width of 8 mm while being pressed with a hot plate type welding machine, A cylindrical body 10 in which the cylindrical mesh 5 and the pair of bands 6 were integrated was obtained. Subsequently, in the obtained cylindrical body 10, the cylindrical mesh 5 portion of the cylindrical body 10 is placed so that the cylindrical mesh 5 portion protruding from between the pair of bands 6 enters between the pair of bands 6. Folded inside. Using an impulse sealer, a portion that becomes the bottom portion 7 of the packaging bag 11 in which the cylindrical mesh 5 and the pair of bands 6 overlap each other is thermally bonded with a welding width of 5 mm to obtain the packaging bag 11. The bottom part 7 of the packaging bag 11 is cut horizontally 10 mm below the part thermally bonded, and the upper part 4 of the packaging bag 11 is horizontally oriented so that the vertical length of the packaging bag 11 is 352 mm. Cut.

[Production of packaging body]
After 9 oranges are put in the obtained packaging bag 11, by using an impulse sealer, two parts of the

packaging bag

11, 15 mm below the upper end 3 and 65 mm below, are thermally bonded with a welding width of 5 mm. A package 1 filled with orange was obtained. The thermal bonding at this time was performed in a state where the cylindrical mesh 5 was folded inside the packaging bag 11 and the cylindrical mesh 5 and the pair of bands 6 overlapped. The package 1 filled with orange obtained in this way was excellent in form retention because the mesh did not stretch and orange did not collect at the bottom of the package 1 even when placed upright.

Example 2
In Example 1, the mesh weave density was changed to 8 warps / 2.54 cm, 5 wefts / 2.54 cm, and the basis weight was changed to 17.4 g / m ^2. The packaging body 11 filled with the packaging bag 11 and orange was produced. The obtained results are summarized in Table 1. The package 1 filled with orange obtained in this way was excellent in form retention because the mesh did not stretch and orange did not collect at the bottom of the package 1 even when placed upright.

Example 3
In Example 1, instead of a uniaxially stretched tape for warp having a thread width of 1.2 mm, a thread thickness of 29 μm, and a fineness of 330 dt, a uniaxially stretched tape for warp having a thread width of 0.5 mm, a thread thickness of 29 μm, and a fineness of 150 dt was used. A packaging body 1 filled with a packaging bag 11 and orange was produced in the same manner as in Example 1 except that a mesh having a basis weight of 10.3 g / m ² was produced. The obtained results are summarized in Table 1. Even when the packaging body 1 filled with orange thus obtained was placed upright, the mesh was stretched and the orange did not collect at the bottom of the packaging body 1. However, in the obtained package 1, there was a portion where the film and the mesh were peeled off due to insufficient adhesion between the film and the mesh.

Example 4
In Example 1, instead of a uniaxially stretched tape for warp having a yarn width of 1.2 mm, a yarn thickness of 29 μm, and a fineness of 330 dt, and a uniaxially stretched tape for a weft having a yarn width of 1.5 mm, a yarn thickness of 23 μm, and a fineness of 330 dt, Both yarns were uniaxially stretched with a width of 1.5 mm, a thickness of 47 μm, and a fineness of 670 dt. The mesh weave density was 8 / 2.54 cm for both warp and weft, and the weight per unit area was 43.5 g / m ² . Except for the above, a packaging body 11 filled with a packaging bag 11 and orange was produced in the same manner as in Example 1. The obtained results are summarized in Table 1. Even when the packaging body 1 filled with orange thus obtained was placed upright, the mesh was stretched and the orange did not collect at the bottom of the packaging body 1. However, when the packaging body 1 filled with orange was produced, the orange was filled to the vicinity of the upper end 3 of the packaging bag 11, so it was difficult to thermally bond the portion 65 mm below the upper end 3 of the packaging bag 11. there were. Moreover, the wrinkle of the mesh in the package 1 was conspicuous.

Comparative Example 1
In Example 1, instead of the 300 mm wide cylindrical mesh roll 8, a plastic net packaging is used in the same manner as in Example 1 except that a 300 mm wide polyethylene cylindrical plastic net roll (commercially available) is used. A bag was prepared, and then a package made of a plastic net filled with orange was obtained. Here, the cylindrical plastic net constituting the cylindrical plastic net roll is a net made of polyethylene formed without weaving by extrusion molding, and the intersection of the nets is crushed smoothly so that the thickness becomes 200 μm. This is a net consisting of a diamond-shaped lattice pattern (diagonal eye length of about 8 mm × 4 mm). The weight per unit area of the plastic net was 45 g / m ² , and the tensile strength and tensile elongation of the plastic net were measured in the same manner as in Example 1. The obtained results are summarized in Table 1. The packaging body made of plastic net filled with orange thus obtained had poor shape retention because the plastic net stretched and orange gathered at the bottom of the packaging body when placed upright. Moreover, the film and the plastic net in the packaging bag were insufficiently bonded, and there were places where the film and the plastic net were peeled off. At this time, when the packaging body made of the plastic net was viewed from the front, one side of the packaging body had a trapezoidal shape with a large bulge, which impaired the beauty.

Further, the coverage ratio and the intersection ratio of the plastic net were obtained by obtaining the digital image of the plastic net using a scanner, analyzing the number of pixels in a 10 cm square of the plastic net using image analysis software, and calculating the following formula. The obtained results are summarized in Table 1.
Coverage rate (%) = (number of pixels in the plastic net portion) / (number of pixels in the plastic net portion + number of pixels in the background portion) × 100
Intersection ratio (%) = (number of pixels in the intersection portion of the plastic net) / (number of pixels in the plastic net portion + number of pixels in the background portion) × 100

Example 5
In a portion where the surface of the cylindrical mesh 5 and the longitudinal end portions 9 of the pair of bands 6 are thermally bonded (width of about 15 mm in the horizontal direction), the woven density of the uniaxially stretched tape in the vertical direction is 12/2. Except having changed to 54 cm, it carried out similarly to Example 1, and produced the package 1 filled with the packaging bag 11 and orange. In this way, by increasing the woven density of the uniaxially stretched tape in the vertical direction of the part that is thermally bonded, the band when the surface of the cylindrical mesh 5 and the longitudinal ends 9 of the pair of bands 6 are thermally bonded. The film constituting No. 6 was not easily wrinkled, had excellent adhesion, and had good workability. Further, the package 1 filled with the obtained orange was excellent in form retention because the mesh did not stretch and the orange did not collect at the bottom of the package 1 even when placed upright.

Example 6
In Example 1, instead of cutting the obtained mesh with a width of 590 mm, the mesh was cut with a width of 624 mm, folded toward the center so that both ends of the mesh overlap each other, and the both ends were welded by a hot plate type welder. A packaging body 1 filled with a packaging bag 11 and orange was produced in the same manner as in Example 1 except that the tubular mesh roll 8 having a width of 300 mm and a volume of 300 m was obtained. The package 1 filled with orange obtained in this way was excellent in form retention because the mesh did not stretch and orange did not collect at the bottom of the package 1 even when placed upright. In addition, when winding up the cylindrical mesh 5, the both ends of the mesh overlapped each other and the welded portion swelled, and thus the cylindrical mesh roll 8 exceeding 300 m could not be obtained.

Example 7
In Example 6, when winding both ends of the mesh while being welded by a hot plate type welder, the winding shaft was wound while periodically moving in the horizontal direction with an amplitude of 30 mm, and a cylindrical shape of 300 mm width and 500 m winding A packaging body 1 filled with a packaging bag 11 and orange was produced in the same manner as in Example 6 except that the mesh roll 8 was obtained. Since the cylindrical mesh roll 8 obtained in this way was less than the cylindrical mesh roll 8 obtained in Example 6, it was possible to suppress the swelling of the welded portions of the mesh overlapped with each other. It was possible to wind up. Further, the package 1 filled with the obtained orange was excellent in form retention because the mesh did not stretch and the orange did not collect at the bottom of the package 1 even when placed upright.

DESCRIPTION OF SYMBOLS 1 Packing body 2 Handle 3 Upper end 4 Upper part 5 Cylindrical mesh 6 Band 7 Bottom part 8 Cylindrical mesh roll 9 Longitudinal end part 10 Cylindrical body 11 Packaging bag 12 Roller 13 Roller 14 Roller 15 Cylindrical 16 Sealer 17 Gusset formation guide 18 Sealer 19 Cutter

Claims

A packaging bag comprising a cylindrical mesh and a pair of bands,
The cylindrical mesh is woven using the uniaxially stretched tape as the warp and the intersection of the warp and weft is thermally bonded, and the uniaxially stretched tape is composed of at least three thermoplastic resin layers to constitute the inner layer. The melting point of the thermoplastic resin constituting the outer layer is lower than the melting point of the thermoplastic resin,
The band is made of thermoplastic resin,
The cylindrical mesh is disposed between the pair of bands, and the surface of the cylindrical mesh and the pair of bands are thermally bonded,
A packaging bag characterized in that a cylindrical mesh and a pair of bands are thermally bonded and closed at the bottom of the packaging bag.
The packaging bag according to claim 1, wherein the cylindrical mesh and the pair of bands are thermally bonded so that the uniaxially stretched tape constituting the cylindrical mesh is disposed in both the vertical direction and the horizontal direction of the packaging bag.
The packaging bag according to claim 1 or 2, wherein the weight per unit area of the cylindrical mesh is 10 to 20 g / m 2 .
4. The packaging bag according to claim 1, wherein the thickness of the uniaxially stretched tape is 15 to 40 μm.
The packaging bag according to any one of claims 1 to 4, wherein the width of the uniaxially stretched tape used for the warp is 0.6 to 1.4 mm.
The packaging bag according to any one of claims 1 to 5, wherein the width of the uniaxially stretched tape used for the weft is larger than the width of the uniaxially stretched tape used for the warp.
The packaging bag according to any one of claims 1 to 6, wherein the tensile strength per unit weight 1 g / m 2 of the cylindrical mesh is 7.5 N / 5 cm or more.
The packaging bag according to any one of claims 1 to 7, wherein the coverage of the cylindrical mesh represented by the following formula (1) is 40 to 70%.
Coverage (%) = 100 − [{(25.4− (A × B)) × (25.4− (C × D)) / (25.4 × 25.4)} × 100] (1)
A: Width of uniaxially stretched tape used for warp (mm)
B: Woven density of uniaxially stretched tape used for warp (main / 25.4mm)
C: Width of uniaxially stretched tape used for weft (mm)
D: Woven density of uniaxially stretched tape used for weft (2 / 25.4mm)
The packaging bag according to any one of claims 1 to 8, wherein an intersection ratio represented by the following formula (2) of the cylindrical mesh is 5 to 20%.
Intersection ratio (%) = {(A × B) × (C × D) / (25.4 × 25.4)} × 100 (2)
A: Width of uniaxially stretched tape used for warp (mm)
B: Woven density of uniaxially stretched tape used for warp (main / 25.4mm)
C: Width of uniaxially stretched tape used for weft (mm)
D: Woven density of uniaxially stretched tape used for weft (2 / 25.4mm)
The woven density of the uniaxially stretched tape in the vertical direction of the portion formed by thermally bonding the surface of the cylindrical mesh and the pair of bands is larger than the woven density of the uniaxially stretched tape in the vertical direction of the portion not thermally bonded. The packaging bag according to any one of 1 to 9.
An agricultural product package comprising the packaging bag according to any one of claims 1 to 10 and filled with agricultural products.
A method for producing a packaging bag comprising a cylindrical mesh and a pair of bands,
The mesh is folded along the longitudinal direction to obtain a cylindrical mesh, the cylindrical mesh is wound up to obtain a cylindrical mesh roll, and then the surface of the cylindrical mesh supplied from the roll and the pair of bands are heated. The method for producing a packaging bag according to any one of claims 1 to 10, wherein bonding is performed.
The manufacturing method of the packaging bag of Claim 12 which forms a gusset along the longitudinal direction of this cylindrical mesh after heat-bonding the surface of a cylindrical mesh and a pair of band.
The method for producing a packaging bag according to claim 12 or 13, wherein when the mesh is folded along the longitudinal direction, the mesh is folded so that both ends of the mesh do not overlap each other, and then a cylindrical mesh roll is obtained.
The packaging bag according to claim 12 or 13, wherein when the mesh is folded along the longitudinal direction, the mesh is folded so that both ends thereof overlap each other, and the tubular mesh roll is obtained by winding the mesh while shifting the overlapping portions. Production method.
A method for producing a crop packaging body in which a crop is filled in a packaging bag composed of a cylindrical mesh and a pair of bands,
The mesh is folded along the longitudinal direction to obtain a cylindrical mesh, the cylindrical mesh is wound up to obtain a cylindrical mesh roll, and then the surface of the cylindrical mesh supplied from the roll and the pair of bands are heated. Glue to form a packaging bag,
12. The method for producing a crop package according to claim 11, wherein the packaging bag obtained is filled with a crop, and the opening of the packaging bag is closed by heat welding.
A cylindrical mesh roll in which the mesh is folded and wound,
The mesh is woven using the uniaxially stretched tape as the warp and the intersection of the warp and weft is thermally bonded, and the uniaxially stretched tape is composed of at least three thermoplastic resin layers and constitutes the inner layer. The melting point of the thermoplastic resin constituting the outer layer is lower than the melting point of the resin,
A cylindrical mesh roll in which the mesh is folded and wound along the longitudinal direction so that both ends of the mesh do not overlap.