JP3935573B2 - Packaging bag - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a packaging bag for filling a solid material, particularly a granular content.
[0002]
[Prior art]
In the case of a packaging bag for packaging granular contents such as grains and feed such as rice and wheat, granular fertilizer, etc., especially as a content, when the packaging bag is piled up on a pallet after filling the contents, the packaging bag If there is no air permeability, it is sealed in a state where air is contained together with the contents. Due to the presence of air enclosed with the contents in the bags, the bags become extremely unstable when stacked.
Therefore, as a method of discharging the air in the bag to the outside of the bag, as shown in FIG. 6, when a non-seal part is formed in a part of the bag end seal part S1, S2, and pressure is applied to the bag In addition, a method has been proposed in which the air in the bag escapes from the non-sealed part, that is, the air escape part NS is formed. (For example, refer to Japanese Patent Laid-Open No. 8-26300 and Japanese Utility Model Publication No. 62-19551).
The air escape portion NS is formed on the end seal side of the bag by cutting out the seal tooth profile so that the content C does not spill out.
As another method, for example, as shown in FIG. 5A, a minute hole 10 may be provided in a part of the bag. The minute hole (hereinafter referred to as a small hole) is sharp. It may be formed by a method of piercing a bag with a simple protrusion or a concave / convex die. Even in the small hole 10 formed by this method, the hole diameter is set such that the content C does not spill out.
In the bag in which the air vent NS for venting air is formed in the seal part of the bag or the small hole 10 is formed in a part of the bag by the piercing method or the uneven punching die, the contents C are grains. In the case of such food, small pests may enter the bag through the air vent NS or the small hole 10 from the outside of the bag and eat the contents C.
In addition, when moisture adheres to the bag, the moisture may penetrate into the bag and wet the contents C, which may cause alteration.
As another method, there is disclosed a method in which a filter tape having air permeability is thermally bonded to the inner surface of a joint portion which holds the gap between both end edges of an air-impermeable packaging material whose inner surface is thermally adhesive. (Actual Sho 51-15682).
With such a method, the invasion of the pests can be prevented to some extent, but problems due to moisture adhesion and the like have not been solved.
As described above, the conventional packaging bag can be provided with a deaeration function for high stacking. However, when moisture adheres to the bag surface, in the case of the small hole method, the Moisture enters the bag and wets the contents. In addition, when the degassing function is imparted by the filter tape, the conventional filter tape can prevent the invasion of pests, but cannot prevent the penetration of moisture.
[0003]
[Problems to be solved by the invention]
For bags filled with granular contents, the technology related to the bag structure and materials that allow the air in the bag to be deaerated when the bag is loaded, and prevents pests and adhering moisture from entering or entering the bag. To do.
[0004]
[Means for Solving the Problems]
A packaging bag for filling and sealing a solid material, wherein the packaging bag is mainly composed of a packaging material and a filter, and the packaging material constituting the bag ( hereinafter referred to as a main material). When the film is drawn out from the roll-shaped roll of the film and formed into a cylindrical shape, a gap is formed at both ends of the main material, and a filter is inserted into the gap to seal both ends of the gap. The packaging material is made of a laminated material in which a base film and a sealant film are laminated via an adhesive layer, and the filter has an air permeability measured by JISP8117 in the range of 5 to 100 seconds / 100 cc, and The one whose water pressure resistance measured by JISL-1092 (high water pressure method) is in the range of 500 to 2,000 mm is used, and the filter is made of polyolefin resin. Including being manufactured as a raw material.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, in order to obtain a bag having air permeability and water resistance, a part of the bag is constituted by a filter having appropriate air permeability and water pressure resistance.
FIG. 1 is a perspective view of a bag of the present invention from (a) a filter surface showing an embodiment, and (b) a perspective view from a filter surface showing another embodiment. 2 is a cross-sectional view of (a) X ₁ -X ₁ part of FIG. 1. When the filter is thermally fused to the inner surface of the main material, the filter is thermally fused to the outer surface of the main material in the same manner as (b). Shown when wearing. FIG. 3 is a cross-sectional view taken along line X ₂ -X ₂ in FIG. 4, (a) a top view of the case as the upper filter side showing a specific example of a packaging bag according to the present invention, a (b) X ₃ -X ₃ parts cross section. Figure 5 is a (a) top view, (b) X ₄ -X ₄ parts cross-sectional view of a case where a small hole side of the packaging bag provided with a small hole was above that used for comparison.
FIG. 6 is a view showing an example of a bag degassing method according to the prior art, (a) a front view of the bag, (b) an enlarged cross-sectional view of X ₅ -X ₅ part, (c) X ₆ -X ₆ part. FIG.
[0006]
The type of packaging bag to which the present invention can be applied is not particularly limited and can be applied to any bag type bag.
As a bag used for packaging the granular contents, a bag of a type generally called a pillow bag, a two-sided seal bag formed by an upper and lower seal of a film formed in a tube shape, and the like are often used.
Further, a three-side seal, a four-side seal, or various types of bags provided with a self-supporting bag or a gusset portion may be used.
An embodiment of the present invention in the back-attached bag will be described. In the present invention, when the film is drawn out from a roll-shaped take-up of a main packaging material (hereinafter referred to as a main material) constituting the bag, instead of performing the palm seal in the back-attached type, the main A gap is formed at both ends of the material, and a filter is inserted into the gap to seal both ends of the gap. That is, a part of the bag is constituted by the filter.
[0007]
More specifically, as shown in FIG. 1 (a) and FIG. 2 (a), a gap 3 is provided at a position where a fin (joint) is to be sealed in a bag of a so-called pillow type, and the gap is filtered. By comprising 2, air permeability can be provided.
A semi-permeable filter that is capable of heat-sealing with the inner or outer surface of the main material at the abutting portion and that allows gas to permeate but not moisture, and constitutes part of the bag as the filter. It is.
[0008]
As described above, the filter used in the present invention is of a grade that allows gas to permeate but not moisture. Moreover, it is preferable that it is a material which can be heat-seal | fused with the said main material.
Specifically, the filter of the present invention has a permeability of 5 to 100 seconds / 100 cc and a water pressure resistance of about 500 to 2000 mm.
The air permeability is a value measured according to JIS P 8117 (that is, expressed as an average number of seconds required for 100 ml of air to pass through a nonwoven fabric having an area of 645 mm ² ).
When the air permeability of the filter is less than 5 seconds / 100 cc, the deaeration is good, but the adhering moisture also permeates and wets the contents. In addition, if a filter with an air permeability exceeding 100 seconds / 100 cc is used, when the bags filled with the contents are stacked, the air in the bags will not be degassed, resulting in poor seating of the bags and pressurization. Even if the method of forcibly degassing is used, time that affects the stacking work is required.
That is, it is difficult or impossible to build up at a normal working speed.
If the air permeability of the filter is within the above range, even if the air permeability is low and this may hinder high stacking, if the packaging bag after filling the contents is properly pressurized Since the air in the bag can be degassed, high stacking is possible.
The water pressure resistance is a value measured according to JIS L 1092 (high water pressure method) (that is, water is applied to the front side of a 15 cm × 15 cm test piece, and the water is 100 KPa {1 Kgf / cm ² per minute. } When the water pressure is applied at a ratio of}, the value of the water pressure when water oozes out from three places on the back of the test piece is shown as an average value)
If the water pressure resistance is less than 500 mm, the water adhering to the filter will enter the bag and wet the contents. Also, if the water pressure exceeds 2,000 mm, there will be no effect more than necessary, but the price of the product becomes expensive due to the increase in the cost of the filter.
The water pressure resistance of the bag is not limited as long as the bag filled with the contents is immersed in water for 10 minutes and the contents stored in the bag do not get wet.
It is a feature of the present invention that moisture penetration into the bag can be prevented by short-time moisture adhesion, etc., apart from adhesion of moisture for a long time or water shower or immersion in water.
[0009]
In the formation of the gap, the width of the gap is about 2 mm to 100 mm, and more preferably 5 mm to 40 mm. When the gap is less than 2 mm, the air in the bag is slowly degassed when the bag is stacked, making it difficult to stack. Further, if the gap exceeds 100 mm, the appearance of the bag may be affected, and no significant effect will be exhibited as a deaeration performance. Further, since the price per unit area of the filter 2 is higher than that of the main material 1, the cost is increased.
[0010]
When the gap 3 in which the packaging material is formed is configured as the filter 2, a winding roll of the filter 2 having a width obtained by adding the seal width on both sides to the width of the set gap 3 is prepared. When the filter 2 is formed into a cylindrical shape, the filter 2 is fed out from a roll and supplied, and is heat-sealed 5 with the main material on both sides of the gap 3. The filter 2 is preferably made of a material that can be heat-sealed with the main material 1. The material of at least the inner surface of the main material 1 of the bag is generally composed of a resin that is fused by heat. Examples of the material include polyolefin resins such as polyethylene, polypropylene, and linear low Examples thereof include a density polyethylene, an ethylene-α / olefin copolymer polymerized using a single site catalyst, an ethylene-vinyl acetate copolymer, and an ionomer. Therefore, it is desirable that the filter 2 used in the present invention is made of a polyolefin resin, and the filter 2 made of a polyolefin resin has water resistance, and depending on the grade, a filter that does not transmit moisture is obtained. Moreover, there is an advantage that it is inexpensive compared with a filter made of other materials.
[0011]
In the present invention, the main material 1 of the bag and the filter 2 are thermally fused with each other preferably by thermally fusing the inner surface of the main material 1 and the filter 2. The outer surface of the material 1 and the filter 2 may be heat-sealed. In this case, at least a portion of the outer surface of the main material 1 where the filter 2 is heat-sealed is provided with a polyolefin resin layer, or a process that allows the filter 2 to be heat-sealed by another method. That's fine.
The bag P of the present invention is to join the end portions of the main material 1 through the filter 2 when making the bag. As shown in FIG. 1 (a), a gap 3 having a necessary width is formed between both ends of the main material 1 of the bag, and this space is defined as a filter 2, and the seal portions on both sides of the filter 2 and the inner surfaces of the end portions of the main material 1. Or it is made by heat-sealing 5 with the outer surface.
[0012]
Further, for the purpose of increasing the degassing speed at the time of high stacking, an air escape portion can be formed in a seal portion (for example, the upper or lower seal portion 7a, 7b) between the main materials 1. The seal-released portion has a water pressure resistance in the form of a bag, for example, with a width and a number so that the contents in the bag are not wetted by immersing the bag in water with the contents filled.
[0013]
As another method of the present invention, as shown in FIGS. 1B and 3, a notch 4 is provided in a part of the main material 1 of the bag to cover the notch 4 and A filter 2 having an area that can be heat-sealed with the main material 1 is applied to the peripheral edge thereof, and adhesion is performed by heat-sealing 5 or the like at the peripheral edge of the notch 4 of the main material 1 of the bag. The size of the notch 4 is set to a necessary area from the air permeability of the filter 2 used and the necessary degassing speed as workability at the time of loading.
The shape of the notch 4 is not particularly limited, and may be, for example, a circle, an ellipse, a triangle, a polygon such as a quadrangle, or other shapes, and two or more of these notches 4 are provided. May be.
In the case of this method, the constituent resin of the main material 1 of the bag and the material of the filter 2 are the same as those in the above method.
[0014]
The area of the notch 4 should be at least a size that shows air permeability so that when the bags filled with the contents C are piled up, the stacking can be performed without any problem corresponding to the work speed, The area is about 1 to 30% of the total surface area of the bag, and more preferably 5 to 10%.
As a method of heat-sealing the filter 2 to the main material 1 in this method, a roll of the filter 2 that covers the notch 4 and has a width to be heat-sealed at the periphery thereof is prepared, and is formed into a cylindrical shape. This is possible by covering the notch 4 from the inner surface or outer surface of the molded bag and thermally fusing the periphery thereof.
[0015]
The sealing method of the main materials 1 when forming the bag from the main material 1 and the sealing method of the main material 1 and the filter 2 in the case of the present invention may be the same method or different methods. There may be. Specific examples of the method include heat sealing, impulse sealing, ultrasonic sealing, and high frequency sealing. In the adhesion between the main material and the filter, the filter may be adhered to the inner surface of the main material of the bag or the outer surface, but the main material 1 has a layer with good thermal adhesion on the inner surface. In many cases, the filter 2 is bonded to the inner surface of the main material 1 because the appearance is not impaired by the end of the filter 2 being inside the bag.
[0016]
As the main material 1 of the packaging bag P of the present invention, various single layers or laminated materials can be used. Examples of the single layer packaging material include polyethylene, polypropylene, ethylene-vinyl acetate copolymer, linear low density polyethylene, ethylene-α / olefin copolymer polymerized using a single site catalyst, nylon, polyester, polycarbonate, polyvinyl Examples thereof include a stretched or non-stretched film formed from a resin such as alcohol or polyethylene terephthalate.
Or the multilayer film which formed two or more types of above-mentioned resin into a film by the co-extrusion method may be sufficient.
[0017]
Moreover, as a laminated film obtained by laminating various films, the simplest combination includes a base film and a sealant film. If necessary, a film or a metal foil that provides a barrier property or a decorative effect may be laminated.
For example, the base film may be paper, cloth, metal foil, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, linear low density polyethylene, ethylene-α / olefin copolymer polymerized using a single site catalyst. It may be a stretched or unstretched film formed from a resin such as coalescence, nylon, polyester, polycarbonate, polyvinyl alcohol, polyethylene terephthalate or the like, or a coextruded film obtained by coextrusion of the resin. Further, a metal such as aluminum, an inorganic compound such as aluminum oxide and silicon dioxide, and other compounds may be deposited on the base film, or a barrier coating agent such as vinylidene chloride may be coated.
[0018]
The main types of sealant films of the laminated type are polyethylene, polypropylene, ethylene-vinyl acetate copolymer, linear low-density polyethylene, ethylene-α / olefin copolymer polymerized using a single site catalyst, nylon, polyester, polycarbonate. A film made of a resin such as polyvinyl alcohol or polyethylene terephthalate is laminated on the base film by using an adhesive or by laminating these resins on the base film by melt extrusion. It may be a packaging material.
In addition to the base material film and the sealant film, another material or a material other than the film can be laminated in the layer configuration of the main material of the lamination type. Specific examples include laminating aluminum foil or metal-deposited film between the base film and sealant film for decorative purposes, or attaching thin paper, non-woven fabric or aluminum foil to the outer surface of the bag. An adhesive may be used for dry lamination with the base film, or an adhesive resin may be used for sandwich lamination with the base film.
[0019]
【Example】
[Example 1]
As the main material 1, a biaxially stretched nylon film 20 μm / DL / L-LDPE 60 μm (DL: dry lamination) was used, and the polished rice was made into a bag for packaging 5 kg of polished rice.
The form of the bag was as shown in FIGS. 4A and 4B, the folded width of the bag was 280 mm, the inner dimension in the longitudinal direction was 470 mm, and the effective filter width W was 36 mm.
As the filter 2, high density polyethylene non-woven fabric 64 g / m ² (trade name, manufactured by Tyvek 1059B DuPont) was used. The air permeability and water pressure resistance of the filter 2 are as follows:
Air permeability 22sec / 100cc [JIS P 8117]
Water pressure resistance 1450mm (JIS L1092)
Met.
[Comparative Example 1]
A biaxially stretched nylon film 20 μm / DL / L-LDPE 60 μm (DL: dry lamination) was used as the main material 1 ′, and the polished rice was made into a bag for packaging polished rice and 5 kg.
The form of the bag was as shown in FIGS. 4A and 4B, the folded width of the bag was 280 mm, the inner dimension in the longitudinal direction was 470 mm, and the effective filter width W was 24 mm.
As the filter, non-woven fabric 70 g / m ² (trade name, manufactured by Elves TO703WDO Unitika Co., Ltd.) made of a fiber made of a polyester resin as a core and polyethylene as an outer material was used. The air permeability and water pressure resistance of the filter are as follows:
Air permeability <1 second / 100cc [JIS P 8117]
Water pressure resistance 222mm (JIS L1092)
Met.
[0020]
[Comparative Example 2]
The main material 1 ′ having the same specifications as in Example 1 is used, and a pillow type bag is formed as shown in FIGS. 5 (a) and 5 (b). The inner dimension is 280mm in folding width and the inner dimension on the long side. It was 470mm. In the long side direction, a perforated type bag having small holes with a diameter of 1.5 mm at intervals of 20 mm was formed.
As for stacking, both the examples and comparative examples were stacked on a standard pallet (1,100 × 1,100 mm). The stacking operation was performed at a speed of 1 bag / 5 seconds.
[0021]
Evaluation method <Deaeration speed>
The deaeration speed when bags were stacked in the above stacking operation was observed. At that time, evaluate whether there is any obstacle to the stacking.
<Actual water pressure resistance>
[0022]
After immersing the bag in water for 10 minutes, pull it up and dry it, then check if the contents have absorbed moisture.
Result [0023]
The deaeration speed was good in both the example and the comparative example, and there was no problem in the workability of stacking on the pallet.
However, in the state filled with polished rice, water did not enter into the bag of the example as a result of immersion for 10 minutes in water, but both Comparative Example 1 and Comparative Example 2 entered the bag, The contents of polished rice have absorbed water.
[0024]
【The invention's effect】
With the bag of the present invention, even if the bags filled with the granular contents are stacked, the height of the stacking is not significantly restricted by the presence of air in the bag.
It is possible to prevent the invasion of pests in the state filled with the contents, and even if the bag comes into contact with water, moisture does not enter from the filter part, and in the state filled with the contents, Even if it encounters rain, etc., or water adheres to it at the kitchen, etc. during use, the contents do not absorb water, and problems such as deterioration and discoloration of the contents can be prevented.
[Brief description of the drawings]
1A is a perspective view from a filter surface showing an embodiment, and FIG. 1B is a perspective view from a filter surface showing another embodiment. FIG. _In the cross-sectional view of _1- X ₁ part, when the filter is heat-sealed to the inner surface of the main material, the filter is heat-sealed to the outer surface of the main material in the same manner as in (b). (a) top view of the case as the upper filter side showing a specific example of the packaging bag due to cross-sectional view of the X ₂ -X ₂ parts [4] the present invention _{b), (b) X 3} -X 3 parts Sectional view [FIG. 5] (a) Top view, (b) X ₄ -X ₄ section sectional view when the small hole surface side of the packaging bag provided with small holes used for comparison is up [FIG. 6] FIG. 11 is a diagram showing an example of a bag degassing method according to the prior art, (a) a front view of the bag, (b) an enlarged sectional view of X ₅ -X ₅ part, (c) an enlarged sectional view of X ₆ -X ₆ part. Figure [Explanation of symbols]
P Bag C of the present invention Contents 1 Main packaging material constituting the bag (main material)
2 Filter 3 Gap 4 Notch 5 Heat fusion part 6 Fin seal 7 Upper or lower seal 10 Small hole S Seal part NS Air escape part

Claims (2)

A packaging bag for filling and sealing solid matter, wherein the packaging bag is mainly composed of a packaging material and partly a filter, and a film is drawn out from a roll-shaped winding of the main packaging material. A gap is formed at both ends of the main wrapping material, and a filter is inserted into the gap to seal the both ends of the gap, and the main wrapping material includes a base film and It consists of a laminated material that laminates a sealant film through an adhesive layer, and the filter has an air permeability measured by JISP8117 in the range of 5 to 100 seconds / 100 cc, and JISL-1092 (high water pressure method) A packaging bag, wherein the water pressure resistance measured by the method is in the range of 500 to 2,000 mm. The packaging bag according to claim 1, wherein the filter is manufactured using a polyolefin resin as a raw material.

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