JPS596783B2 - Degassable multi-bag - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION According to the present invention, air permeable convex striped films made of Netsucho plastic resin are stacked on top of each other through the convex stripe side surface of at least one of the convex striped films. This relates to a deaerating multi-layered bag forming the inner and outer layer walls of the main body of the packaging bag.

The degassing multi-layer bag of the present invention has excellent degassing properties when filling the packaging bag with powder and granules, as well as the degassing properties of the package immediately after filling the packaging bag with powder and granules. The packages were stacked one on top of the other.

This is a multi-layer bag with a valve opening made of Natsumachi plastic resin, which allows the packages to be stacked stably in multiple tiers, since slippage at the contact surfaces between the packages is prevented. Conventionally, packaging bags with a valve made of Atsumachi plastic resin (film) have too high a sealing performance, so when filling the bag with powder or granules, the gas (air) that accompanies the powder or granules cannot be sufficiently removed. In extreme cases, the bag may not be able to be filled midway through, the packaging bag may swell and eventually burst, or the bag may not be able to be filled at all. Even so, immediately after filling, the excess gas in the packaging bag remains without being degassed, and the packaging bag filled with powder or granules becomes swollen, making it difficult to store or transport. Because they had the disadvantage that they could not be stably stacked in multiple stages, they were not actually used as packaging bags for heavy-duty packaging. Recently, a packaging bag with a valve opening, which is made of an air permeable film having a large number of fine ventilation holes in a Netsumachi plastic resin film, has been proposed as a packaging bag for heavy duty packaging of powder and granular materials.

Packaging bags made of thermoplastic resin film that have ventilation holes can cause powder to blow out at the same time as air is removed from the ventilation holes, which can cause problems in the working environment of the packaging workshop. However, packaging bags made of film that have ventilation holes that prevent powder from spewing out do not have sufficient deaeration performance. In other words, it has been almost impossible to provide a ventilation hole in the Atsumachi plastic resin film that hardly causes powder to be ejected and has sufficient deaeration performance. In order to improve the above-mentioned problems regarding powder ejection and degassing,
A double bag has been proposed in which the inner and outer layer films of the bag have ventilation holes and the ventilation holes of the inner and outer layer films do not overlap, as described in Japanese Patent No. 4-26513. Even if the powder is ejected from the ventilation hole, it remains between the inner and outer layers and does not eject to the outside, resulting in a considerable improvement in powder ejection.However, even with this packaging bag, the inner and outer layers of film adhere tightly and exhibit sufficient degassing performance. Something happened that didn't happen. On the other hand, since the outer layer of the packaging bag with a valve made of Atsumachi plastic resin film is composed of a film with a smooth surface, the packaging bag is filled with powder and granules, and the air is sufficiently degassed. Even if it is a package, the outer film surfaces of the package easily slip together, making it difficult to stack the packages in more than a few tiers, and even if they can be stacked in more than a few tiers, it will be very inconvenient. It had the disadvantage that it was stable and small, but could easily be dislodged by shock or shaking.

As a result of intensive research into a packaging bag with a valve spout that has improved powder ejection and deaeration performance as well as slip resistance of the packaging bag, the inventors found that the inner and outer layers of the packaging bag are made of breathable convex striped films. The deaerating multi-bag of the present invention, which is constructed as such, solves the above-mentioned problems of powder ejection, degassing, and slipping all at once. Immediately after that, he discovered that it was possible to stably stack them in multiple stages, and completed this invention.

That is, the present invention provides an air permeable protrusion made of a hot plastic resin that is integrally molded to have a plurality of arranged protrusions on at least one side, and has a large number of ventilation holes in the plane between the protrusions. The striped films are stacked on top of each other through the surface having the protrusions of at least one of the striped films, and form inner and outer layer walls of the main body of the packaging bag having a valve opening. The present invention relates to a deaerating multi-layer bag.

In the deaerating multi-layer bag of the present invention, the inner and outer layers of the main body of the multi-layer bag are respectively composed of air-permeable ridge-lined films which are overlapped with each other through the surface having the ridges of at least one ridge-lined film. Therefore, the plurality of protrusions prevent the films with protrusions on the inner and outer layers from coming into close contact with each other over the entire surface, and a narrow gap is formed between the inner and outer layers.

Therefore, in the deaerating multi-layer bag of the present invention, degassing occurs through the vents in the inner layer, the gaps between the inner and outer layers, and the vents in the outer layer.
This is done very smoothly, and the small amount of powder that is ejected from the ventilation holes in the inner layer stays in the above-mentioned voids and is hardly ejected to the outside via the deaeration route mentioned above. . Furthermore, the deaerating multi-layer bag of the present invention has an excellent effect of preventing slips due to the protruding stripes on its outer surface, and the multi-layer bag is packed with powder and granules and the package is then palletized. They can be stacked in layers of 10 or more.

Hereinafter, the degassing multiple bag of the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a perspective view showing an example of the state of a package obtained by filling and packaging powder or granular material in a deaerating multi-bag according to the present invention.

Fig. 2 is a plan view of the deaeration multi-bag used in Fig. 1 (before filling with powder or granular material), and Fig. 3 is a cross section taken along the line AA' of the deaeration multi-bag in Fig. 2. FIG. 3 is an enlarged cross-sectional view. FIG. 4 is a perspective view showing an example of the breathable convex striped film forming the inner and outer layer walls of the deaerated multi-layer bag of the present invention.

In this invention, a breathable convex striped film 2 forming the inner and outer layer walls of a deaerating multi-layer bag 1 as shown in FIGS. 1 to 3 is used.
is a film made of hot plastic resin that is integrally molded to have a plurality of arranged protrusions 2 on at least one side, and has multiple ventilation holes 4 in the plane between the protrusions 3. Yes (see Figure 4).

The breathable convex striped film 2 may be manufactured from a convex striped film manufactured by any known extrusion method, but for example, it may be produced by an inflation method or a T-die method. The shape of the discharge slit part of the mold is matched to the cross-sectional shape of the film with protrusions in the extrusion direction, and ventilation holes are made with a needle or the like in the film with protrusions extruded with the mold. Alternatively, a semi-molten, softened film that has been extruded into a film shape using a conventional method is sandwiched between an embossing roll and a presser roll that have grooves arranged corresponding to the ridges to form the ridges. It is sufficient if the formed protruding striped film is made with ventilation holes using a needle or the like.

In the breathable film 2 with protrusions, the protrusions 3 may be either linear or curved, and the method of arrangement of the protrusions and the cross-sectional shape of the protrusions are also particularly specified. isn't it.

For example, as shown in the drawing, the breathable film 2 with protrusions is formed by arranging a large number of protrusions 3 parallel to each other in the direction along the side edge (the extrusion discharge direction). However, it is suitable because it can be easily manufactured by the usual inflation method or T-die extrusion method using a fixed mold.

The film 2 with protrusions may be formed by arranging a large number of parallel protrusions 3 that intersect in the side edge direction (extrusion direction). The attached film 2 is manufactured by extrusion molding while rotating an inflation extrusion mold at a constant speed in a constant direction. Furthermore, the film 2 with protrusions may have protrusions 3 arranged in a wavy line in the side edge direction (extrusion direction).
is manufactured by extrusion molding while periodically reversing a mold for inflation extrusion molding at regular intervals. When the protruding stripes 3 of the protruding striped film 2 are formed by extrusion molding, they are usually continuous protruding stripes, and when the protruding stripes exhibit the effects of the present invention, the protruding stripes 3 are formed by extrusion molding. It has a huge impact.

The protrusion 3 does not necessarily have to be a continuous linear protrusion, but may be an intermittent protrusion such as a dotted line or a chain line, for example. In this invention, the convex striped film 2
The object of the present invention can be sufficiently achieved if a plurality of the above-mentioned protrusions 3 are arranged and formed on one side, but the protrusions 3 are formed on both sides of the film. Of course, film can also be used.

In the film 2 with protrusions, the height of the protrusions 3 (height from the surface of the flat surface of the film 2 with protrusions to the top of the protrusions) is 0.01 to 1.0. Especially 0.05-0.

It is preferable that it is about 8 mm, and the width of the bottom of the protrusion 3 is 0.1 to 2 m7! L1 is preferably about 0.5 to 1 m1L.

Further, the cross section of the protruding stripes 3 of the protruding striped film 2 in the longitudinal direction may have any shape such as a semicircle, a semiellipse, a triangle, a quadrilateral, or a combination of these shapes. In this invention, the film 2 with protrusions is not particularly limited in terms of the arrangement density of the protrusions 3, but considering the degassing properties and slip prevention effect when used in degassing multi-bags, 5 to 50 degrees within 50 degrees in the direction perpendicular to the extrusion direction of the convex striped film 2
It is preferable that the arrangement density of the protrusions 3 is such that the protrusions 3 have 0 protrusions, particularly 10 to 250 protrusions, and more preferably 20 to 200 protrusions.

It is appropriate that the protruding striped film 2 has a uniform arrangement density of protruding stripes over its entire surface, but it is not necessarily necessary that the protruding stripes have a uniform array density over the entire surface. , it may have protrusions arranged in a suitably dense arrangement. In this invention, as shown in FIG. 4, the film 2 with protrusions has a height of 0.05 to 0.8 mm, and an interval between the protrusions 3 of 0.05 to 0.8 mm. 2-5? , especially 0.3~
A film with protrusions of about 2c7n and having parallel linear protrusions arranged uniformly over the entire surface on one side of the film with protrusions is extrusion molded. It is the most suitable ridged film because it is easy to manufacture and has excellent degassing properties and slip prevention effects for degassing multiple bags using the ridged film.

Note that the film 2 with ridges may have a suitable reinforcing thread built into the ridges 3 along the ridges, and such a film with ridges has increased mechanical strength. be.

In this invention, the film 2 with protrusions has a large number of ventilation holes 4 on the plane between the above-mentioned protrusions, and has air permeability necessary for deaeration.

The ventilation holes 4 of the convex striped film 2 have an inner diameter of about 4 mm or less, especially 0.01 to 3 mm, and 0.01 to 3 mm.
．． The diameter is preferably about 1 to 2.5 mm; if the inner diameter becomes too large, it will not be possible to prevent the powder from blowing out, which is undesirable. If the inner diameter becomes too small, the deaeration performance will not be sufficient, which is not preferable. The shape of the opening of the vent hole 4 of the film 2 with protrusions is preferably circular or oval, but may also be triangular, square, star-shaped, or the like.

In this film 2 with protrusions, the vent holes 4 may be opened at any arrangement and density, but in particular, the density of the vent holes 4 is such that the area of the film with protrusions 2 is 0.25 Tr1 (1/
2-1000 ventilation holes per 4Tr1), especially 10-5
The arrangement density is preferably 00, more preferably 20 to 200.

Further, in the film 2 with convex stripes, the distance between adjacent vent holes 4 is at least 0.5 CT! In order to make it more than
In general, in the present invention, the smaller the inner diameter of the vent holes 4 in the film 2 with convex stripes, the smaller the distance between adjacent vent holes. It is preferable to make the air holes small and to increase the density of the air holes. When the inner diameter of the air holes is large, it is preferable to make the interval between the air holes sufficiently large and to reduce the density of the air holes.

Note that it is preferable for the film 2 with protrusions to have the vent holes 4 evenly and regularly arranged throughout the film, but it is not necessarily the case that the vent holes 4 are arranged uniformly and regularly throughout the film. The ventilation holes 4 may not be distributed uniformly, but may be distributed in an appropriate density.

In the present invention, the film with protrusions may have the same ventilation holes in both the inner and outer layers, but the inner diameter, arrangement, etc. of the ventilation holes in the inner and outer layers may be different.
In this invention, the air permeable film 2 with ridges has a thickness of the plane portion between the ridges when used in multiple bags for packaging powder and granular materials in multiple layers. The thickness may be any thickness as long as it exhibits the required strength, and in this invention, the thickness is approximately 20 to 500 μm, particularly 25 to 200 μm.
B5 preferably has a thickness of about μ, and more preferably has a thickness of about 0.1 to 2 times, particularly about 0.2 to 1 time, the height of the above-mentioned protruding strip 3.

The material of the film 2 with protrusions may be any thermoplastic synthetic resin such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyester, polyamide (nylon-6), or the like.

In this invention, as shown in FIG. 3, in the deaeration multiplex body 1, the above-mentioned air permeable convex striped films 2, 2 have a convex strip 3' on at least one of the convex striped films 2'. It is a multi-layered bag which is stacked on top of each other via the side surfaces and forms the inner and outer layer walls of the main body of the packaging bag having a valve opening 5.

Therefore, in the deaerating multi-layer bag 1 of the present invention, the inner and outer layers of the main body are not in full contact with each other due to the ridges 3', and a narrow gap 7 is formed between the inner and outer layers. Therefore, the gas that accompanies the filling of the powder into the inside 8 of the multi-layer bag 1 flows through the vent holes 4/ of the inner layer ridged film 2', the gaps 7 between the inner and outer layers, and the outer layer ridged film 2. The air is smoothly degassed through the ventilation holes 4. In addition, the deaerating multi-bag 1 of the present invention has the advantage that even if a small amount of the powder filled inside the bag blows out from the ventilation hole 4' of the inner layer convex striped film 2' into the gap 7 between the inner and outer layers, the outer layer By the time it reaches the ventilation holes 4 of the film 2 with protrusions, it loses its fluidity and is caught in the protrusions 3' between the inner layer and the outer layer, and the multi-layered bag 1
It almost never erupts to the outside. That is, the deaerating multi-layer bag 1 of the present invention has excellent deaerating properties due to the plurality of convex stripes between its inner and outer layers, and also prevents the powder from blowing out to the outside. This is an excellent multi-bag. On the other hand, the deaerating multiple bag 1 of the present invention is
As shown in Figures 1 to 3, the film 2 with protrusions forming the outer layer has a large number of arranged protrusions 3, which have excellent anti-slip performance (preventing load from buckling). There is. The slip prevention performance of this multiple bag 1 is as follows.
As shown in the figure, the convex striped film 2 forming the outer layer
The best performance is shown in multi-layered bags in which the surface with the ridges is on the outside.

However, even in the case of a multi-layer bag in which a film with protrusions that has protrusions on only one side forms an outer layer with the side without protrusions on the outside, the protrusions inherent between the inner and outer layers of the multi-layer bag Therefore, it exhibits far superior slip prevention performance (load collapse prevention performance) compared to multi-layered bags made of films with ridges that do not stick. In this invention, the convex striped films 2 and 2' forming the inner and outer layer walls of the main body of the deaerating multi-layer bag 1 have a plurality of stripes between the inner and outer layer walls when they are overlapped. If it looks like there are ridges,
Other overlapping states are not particularly limited, and various overlapping states may be used.

As shown in FIG. 4, the convex striped films 2 and 2' are placed so that their surfaces with the convex stripes 3 and 3/ face the same upward direction, and the convex stripes 2 and 2' are placed in the same upward direction. When the strips 3 and 3' are superimposed in the same direction, as described above, it is preferable in terms of both degassing performance and anti-slip performance.

The overlapping state of the convex striped films is determined by the direction of the convex stripes of the inner layer convex striped film 2' and the convex striped film 2' of the outer layer.
They may be overlapped in such a way that the directions of the protrusions ′ cross each other. In addition, in the present invention, the protruding striped films forming the inner and outer layer walls may have exactly the same arrangement of the protruding stripes; It may be completely different,
For example, the inner layer of the film with ridges may have parallel linear ridges, and the outer layer of the film with ridges may have arranged curved (wavy line) ridges. .

In this invention, the protruding striped films forming the inner and outer layer walls of the deaerating multi-layer bag 1 do not need to be bonded together, but are rather glued together other than the heat-sealed portion at the periphery of the multi-layer bag. It is preferable from the viewpoint of degassing that the adhesive is not glued tightly.

In this invention, the deaerating multi-layer bag 1 has inner and outer layer walls made of films with protrusions as described above, and a valve opening 5.
This is a multi-layer bag for heavy-duty packaging of powder and granular materials. The valve port 5 may be any type of valve port known in the art, and examples thereof include a Bates valve port, a pocket valve port, an outer cylinder valve port, an inner cylinder valve port, and the like. .

In this invention, if a smooth film (a film without protrusions) is attached to the inner circumferential surface of the valve port, the powder or granules will be released from the valve port after the powder or granules are filled and packaged. This is preferable because it prevents the liquid from spouting out. In the deaerating multi-bag 1 of the present invention, when the peripheral edge of the main body is heat-sealed together with the inner and outer layers at the heat-sealing part 6 as shown in FIG. Multi-layered bags are preferred because they have excellent strength.

In the multi-layered bag of the present invention, the periphery of the main body thereof may be machine-sewn as well as heat-sealed. The multi-layered bag of the present invention has the same overall shape as a known packaging bag capable of packaging powder and granular materials in multiple layers, such as a pillow-type packaging bag, a square-bottomed packaging bag, a cassette-type packaging bag, etc. It may have any overall shape.

In addition to the inner and outer layers made of the above-mentioned convex striped film, the multi-layer bag of the present invention can also be made of air permeable packaging bag materials such as kraft paper, plastic film with ventilation holes, stretched cloth, woven fabric, non-woven fabric. It may also be a multi-layer packaging bag in which the inner layer is made of Example 1 High-pressure ethylene monovinyl acetate copolymer (vinyl acetate unit content: 3%, density: 0.9309/Crit, M; 0
．． 59/10 min) was used to extrude the inflation method to produce a film with protrusions having parallel linear protrusions as shown in Fig. 4 (thickness of the film portion: 100).
μ, height of ridges: 0.4m1L1 density of ridge array; 1
57 strips/50 CTrL) were molded.

A large number of ventilation holes with a diameter of 500 μm were uniformly opened on the film with a diameter of 500μ at intervals of 5CTn both vertically and horizontally, and the film was cut into squares measuring 72.5C7rL1 and 50.5cm in length (in the same direction as the protrusions). A first breathable film with convex stripes was manufactured, and on the other hand, ventilation holes with a diameter of 200μ were vertically (
Same direction as the ridges) 10cm apart, 35cm wide! Openings were made at RL intervals and cut into a rectangle with length (in the same direction as the ridges) of 72.50 fIL1 and width of 50.5 cm to produce a second breathable ridge-lined film.

As shown in FIG. 4, the first and second breathable films with protrusions are oriented in the same direction,
The first breathable convex striped film is used as an inner layer, and the two sets of first and second breathable convex striped films are stacked one on top of the other, and the peripheral edges thereof are heat-sealed. At the same time, pocket valve openings were formed at the corners to produce a pillow-type multi-layer bag with valve openings measuring 72C7N1 in length and 50 cm in width.

Fill the multilayer bag with 20 kg of slaked lime through the pocket valve (impeller type powder filling machine; manufactured by Tokyo Kagaku Kikai Co., Ltd.).
, it was filled in about 8 seconds.

Immediately after the filling of the powder is completed, the packaging bodies are stacked in two tiers, and Table 1 shows the time required for the height of the width of the lower packaging bag to decrease by 10% (indicating degassing performance). Furthermore, Table 1 shows the angle at which the upper packaging bag begins to slip (indicating slip property) when the degassed packaging bags are stacked in two tiers and the entire bag is gradually tilted. Furthermore, Table 1 shows the number of stable stacking stages when packaging bags that have been filled with powder are sequentially stacked on pallets with five bags per stage.

Note that this package did not prevent powder from spewing out from the ventilation holes.

Example 2 As a film with protrusions, the density of the arrangement of protrusions was set to 75/
50CT! In addition to using an L-shaped film with convex stripes,
Multiple bags were manufactured in the same manner as in Example 1.

When the packaging bag was filled with powder in the same manner as in Example 1, the filling time was 7.5 seconds. Table 1 shows the various performances of the obtained package. Example 3 As a first breathable film with ridges, the direction of the ridges is the horizontal direction, and the horizontal length is 50.5 CTIL1 The direction perpendicular to the direction of the ridges is the vertical direction, and the vertical length is 72.5 CTIL.
Example 1 was carried out in the same manner as in Example 1, except that the first and second breathable films with convex stripes were stacked on top of each other so that the convex stripes were perpendicular to each other to form the inner and outer layers of the packaging bag. A multi-layer bag was manufactured.

Approximately 6.5 kg of powder was filled in the multi-bag in the same manner as in Example 1.
It was possible to fill the powder in seconds. Other results first
Shown in the table. Comparative Example 1 A multi-layer bag was produced in the same manner as in Example 1, except that a breathable plastic film without any protrusions was used.

When the multiple bags were filled with powder in the same manner as in Example 1, the filling time was 13 seconds. The other performance of the multi-bag is the first.
Shown in the table.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the state of a packaging bag in which the deaerating multiple bag of the present invention is filled with powder or granular material twice. Figure 2 shows one of the degassable multiple bags of the present invention before being filled with powder or granules.
FIG. 3 is a plan view showing an example, and FIG. 3 is a partially enlarged sectional view showing the AN line cross section thereof. FIG. 4 is a perspective view showing an example of a situation in which the breathable convex striped films are overlapped. 1; Multiple bags, 2; Breathable convex striped film (outer layer), 2
′; Breathable film with ridges, 3; ridges, 4; Ventilation holes, 5
; Valve opening, 6: Heat sealing part, 7: Gap, 8: Inside of multiple bag.

Claims (1)

[Claims] 1. A thermoplastic resin breathable ridged film that is integrally formed to have a plurality of arranged ridges on at least one side and has a large number of ventilation holes in the plane between the ridges, 1. A degassing multi-layer bag, characterized in that at least one of the films with protrusions is stacked on top of the other with the protrusions on the surface thereof, forming the inner and outer layer walls of the main body of the packaging bag having a valve opening.