JP5183668B2 - Powder packaging bags - Google Patents

Description

  The present invention relates to a powder packaging bag. More particularly, the present invention relates to a powder packaging bag having anti-slip properties and capable of being stacked.

  A conventional synthetic resin bag is embossed on a pair of wide front and rear walls of the bag as an anti-slip measure to form a number of protrusions protruding from the outer surface. This is based on the idea that if a large number of protrusions are formed, more friction will be obtained. In other words, the protrusions on the lower wall will prevent slippage between the pallet and the floor surface, and the upper wall connects the lower surface of the other bags stacked above and the protrusions, so-called rough surfaces. Since the contact was made, friction was obtained. In addition, since there are protrusions on both sides, the anti-slip property of the stacked bags was hardly affected regardless of which of the front and rear walls is up or down.

  Other methods for improving the anti-slip property include a method for adjusting the amount of the antistatic agent and a method for preventing slip by applying an anti-slip solution to the surface.

  Patent Document 1 describes a synthetic resin heavy bag (hereinafter referred to as a heavy bag) that is characterized by an opening mechanism. The breaking line for opening the heavy bag has air permeability. Therefore, when a plurality of bags are stacked, the air in the bags is degassed from the breaking line, and the stacked state of the bags can be stabilized.

  Patent Document 2 describes a granular material packaging bag in which two synthetic resin sheets are overlapped, both side edges are thermally bonded with discontinuous lines, and the bottom is thermally bonded with continuous lines. Embossed irregularities are formed on both sides or one side of this so that the inner surface is convex. Therefore, when a large number of bags are stacked, the air in the bags can quickly escape through the irregularities of the discontinuous portions on both side edges, and the stacked state can be stabilized.

  Patent Document 3 describes a packaging bag. The packaging bag of this document is composed of a plurality of bags that are continuous in the longitudinal direction, and the connecting portion is formed with a bend by embossing. Therefore, when the connecting portion is torn, the opening is easily opened by the bend. be able to.

Japanese Patent No. 3054653 JP 2007-137455 A JP 2006-176205 A

  When plastic bags are stacked, they are more slippery than bags made of other materials such as paper. Therefore, embossing is performed on the upper and lower surfaces related to stacking to form protrusions or unevenness, and the unevenness of one bag is bumped against or interferes with the unevenness of the other bag to prevent mutual slippage. It was. However, it is still inferior in slip resistance as compared with the case where paper bags are stacked. In addition, the anti-slip solution should be applied in an environment where it is likely to become hot due to the influence of the outside air temperature, such as in a sealed space such as a container. End up. Furthermore, the adjustment of the amount of antistatic agent is subject to change due to seasonal factors (temperature and humidity), and the slip resistance is not stable.

In the heavy bag of Patent Document 1, the air in the bag is degassed from the breaking line in order to stabilize the stacked state of the bags.
On the other hand, in the bag of Patent Document 2, two synthetic resin films on which irregularities are formed are overlapped so as to be concave on the outside and convex on the inside, and their side edges are welded discontinuously. Therefore, the air in a bag can be deaerated from a discontinuous gap. Note that this document describes that an embossed film has a small contact area, and thus becomes slippery (see paragraph [0006] of Patent Document 2). And it is described that it becomes easy to slip when the convex part is outside (see paragraphs [0015] and [0025] of Patent Document 2). That is, it seems to be a technique for improving anti-slip properties in the order in which concave portions> smooth surface> convex portions are formed on the outer surface. However, it is not clear what kind of idea the anti-slip property is enhanced.
In Patent Document 3, embossing is not used for improving the slip resistance.

  Then, this invention makes it a subject to provide the bag for the packaging of the granular material which improved anti-slip property.

Bags for packaging of granular material of the present invention (claim 1), packaging becomes closed by bonding the faces thereof opposite the lower end of the synthetic resin sheet of the formed tubular shape by an inflation processing granule A bag for a front wall, having a front wall and a rear wall, the front wall is embossed outwardly from the inside to be a front wall when the cylindrical sheet , A number of protrusions projecting from the outer surface are formed, the surface of the rear wall is formed smoothly, and when stacking a plurality of bags, the protrusions of one bag bite into the smooth surface of the other bag, It is characterized by preventing slipping between the bags.

Such a powder packaging bag has a Young's modulus MD1000 / TD1500 to MD3500 / TD4000 kg / cm ² of the sheet, and a thickness of 0.1 to 0.23 mm. Is formed with a substantially conical shape tapered outwardly on the opposite side of the depression, and the height from the outer surface of the front wall of the projection is 0.2 to 0.4 mm. Further, it is preferable that the diameter of the bottom surface on the outer surface is 0.80 to 1.5 mm. MD is the vertical direction, and TD is the horizontal direction. The longitudinal direction is an axial direction when a cylindrical sheet is formed by inflation processing or the like, that is, a direction in which the sheet is formed (forming direction). On the other hand, the lateral direction is a direction perpendicular to the forming direction (longitudinal direction) on the plane of the sheet.

  Further, the front wall and the rear wall have a substantially rectangular shape that is long in the vertical direction, and the projections are arranged in a substantially strip shape extending in the vertical direction in a range excluding the vicinity of the left and right side edges of the outer surface of the front wall. (Claim 3).

Furthermore, it is preferable that a plurality of the belt-like portions are provided, and the belt-like portions are arranged rotationally symmetrically.
Moreover, the manufacturing method of the bag for packaging of the granular material of the present invention (Claim 5) is a method of manufacturing the bag for packaging of the above-mentioned granular material, in which compressed air is blown into the extruded tube. Inflation processing for expanding and forming into an elongated cylindrical member, and an embossing step for forming a large number of projections by pressing the embossed roller outward from the inside of the obtained cylindrical member. It is characterized by that.
Further, in such a method for manufacturing a bag for packaging granular material, the embossing is performed by an embossing apparatus provided with the embossing roller, and the embossing apparatus is vertically long and downward in the front-rear direction. The roller is provided on the front and rear surfaces above and is housed inside the cylindrical member, and the roller has a cylindrical member interposed therebetween. It is preferable that the cylindrical member is sandwiched by a support roller fixed to the frame, and the embossing apparatus is suspended.

  The bag for packaging the granular material of the present invention (Claim 1) is capable of improving the anti-slip property because the protrusions bite into a smooth surface when the bags are stacked. Therefore, the use of a stretch film or the like surrounding a plurality of stacked bags can be reduced. Further, since the rear wall of the bag is formed smoothly, the smoothness can be made a clean printing surface.

A bag for packaging of such granular material, the Young's modulus of the sheet is at ^{MD1000 / TD1500~MD3500 / TD4000kg / cm 2} , and a thickness 0.1~0.23mm
The protrusion is formed with a depression by pressing on the inside thereof, and is formed in a substantially conical shape that tapers outward on the opposite side of the depression, and has a height from the outer surface of the front wall of the protrusion. Is 0.2 to 0.4 mm, and the diameter of the bottom surface on the outer surface is 0.8 to 1.5 mm (Claim 2), the strength of the protrusion can be increased and the bite is deepened. be able to.

  Further, the front wall and the rear wall have a substantially rectangular shape that is long in the vertical direction, and the protrusion is disposed in a substantially strip shape that extends in the vertical direction within a range excluding the vicinity of the left and right side edges of the outer surface of the front wall. (Claim 3), the longer the long side of the front wall, the larger the contact area in the vicinity of the center, and the anti-slip performance is improved.

Further, when a plurality of the belt-like parts are provided and the belt-like parts are arranged rotationally symmetrically (Claim 4), since the belt-like parts are arranged at equal intervals, the left and right sides of the bag are reversed. However, the same slip resistance can be obtained.
Moreover, the manufacturing method of the bag for packaging of the granular material of the present invention (Claim 5) is a method of manufacturing the bag for packaging of the above-mentioned granular material, in which compressed air is blown into the extruded tube. Inflation processing for expanding and forming into an elongated cylindrical member, and an embossing step for forming a large number of projections by pressing the embossed roller outward from the inside of the obtained cylindrical member. Therefore, the manufactured bag has the same function and effect as the above-mentioned bag for packaging powder.
Further, in such a method for manufacturing a bag for packaging granular material, the embossing is performed by an embossing apparatus provided with the embossing roller, and the embossing apparatus is vertically long and downward in the front-rear direction. The roller is provided on the front and rear surfaces above and is housed inside the cylindrical member, and the roller has a cylindrical member interposed therebetween. When the cylindrical member is sandwiched between the supporting rollers fixed to the frame and the embossing device is suspended (Claim 6), the manufactured bag is the above-mentioned bag for packaging powder. The same effect is obtained. Moreover, an embossing apparatus can be arrange | positioned inside a cylindrical member.

FIG. 1a is a perspective view showing a bag for packaging powder (hereinafter simply referred to as a bag) according to the present invention, and FIG. 1b is a perspective view showing the appearance of the bag of FIG. 1a packed with contents. Fig. 2a is a schematic view showing a state in which the bags of Fig. 1 are stacked, and Fig. 2b is an enlarged sectional view of a portion A of Fig. 2a. It is the schematic which shows the manufacturing method of the bag of this invention. FIG. 4A is an enlarged perspective view of a main part showing a state of the embossing process, and FIG. 4B is an enlarged perspective view of a main part shown in FIG. 4A. FIG. 5 is a perspective view showing the embossing apparatus of FIG. 4a. FIG. 6 is a front view showing a roll-shaped member.

  First, the bag of the present invention will be described with reference to FIG. The bag 1 has a cylindrical sheet (peripheral wall) 2 with its lower end closed to a bottom, and its upper end opened. The lower ends of the peripheral walls 2 are overlapped with each other, and the surfaces are closed by a technique such as heat welding or sewing (see reference numeral 2a). On the other hand, the upper end is closed by the above method after the contents are put into the bag 1 (see reference numeral 2b). The bag 1 is folded flat and includes a front wall 3 and a rear wall 4 on the opposite side.

  FIG. 1b shows a state where the contents are packaged in the bag 1 of FIG. 1a. When the contents are put in the vicinity of the upper, lower, left and right side edges of the bag 1, the bag 1 is rounded and bulges outward. The swelled portions are the top 5, the bottom 6, the left wall 7, and the right wall 8, respectively. In the bag 1 shown in FIG. 1b, these ranges are not clear. However, the peripheral wall 2 may be preliminarily provided with a crease line, or a bottom plate or the like may be inserted to provide the top 5, the bottom 6, the left wall 7, and the right wall 8. The bag 1 shown in FIGS. 1a and 1b is a pillow type, but may be a gusset type in which the left and right walls 7 and 8 in FIG. 1b are folded inward.

The front and rear walls 3 and 4 are formed wider than the left and right walls 7 and 8. A protrusion 9 protrudes outward from the outer surface of the front wall 3. In the figure, the projection 9 is formed on the front wall 3 in two strip-like areas 3a and 3a extending in parallel to the longitudinal direction thereof. On the other hand, the outer surface of the rear wall 4 is smoothed. Here, the term “smoothed” means that the rear wall 4 is smoother than the front wall 3 because no projection 9 is formed on the rear wall 4. A smooth process such as pressing the rear wall 4 may be performed.

  As for the size of the bag 1, the width (height) of the peripheral wall 2 is 350 to 1000 mm, the width of the front and rear walls 3 and 4 is 300 to 650 mm, and the width of the left and right walls 7 and 8 is 80 to 210 mm. .

As the material of the peripheral wall 2 used for the bag 1, various synthetic resins such as polyethylene (LDPE, HDPE) or polypropylene (OPP, CPP) are used, and polyethylene is particularly preferable. Moreover, the thickness is 0.1-0.23 mm, Preferably it is 0.12-0.2 mm. Furthermore, the Young's modulus of ^{MD1000 / TD1500~MD3500 / TD4000kg / cm 2} .

  FIG. 2 a shows a state in which a large number of bags 1 of FIG. 1 are stacked on a pallet 10. One guideline for the number of bags to be stacked is the number of bags integrated with a stretch film. In the figure, the front wall 3 of the bag 1, that is, the surface with the protrusions 9 is placed downward. Then, another bag 1 ′ is stacked on the upper surface of the rear wall 4 of the bag 1 with the front wall 3 facing down. When stacked in this manner, the front wall 3 on which the projection 9 of the upper bag 1 ′ is formed and the flat rear wall 4 of the lower bag 1 are in contact. Therefore, the load increases as it goes downward and as many bags are stacked, and the protrusion 9 of the upper bag 1 ′ deeply bites into the smooth surface of the rear wall 4 of the lower bag 1 to improve the slip resistance. be able to. In addition, since the surface with the protrusion 9 is on the bottom, the content is pressed near the base of the protrusion 9 by the load from above, so the vicinity of the base of the protrusion 9 is firmly supported, Ensuring bite into the bottom surface. And the protrusion 9 of the bag 1 in the lowermost layer can obtain friction with the pallet 10 and the floor surface. Although not shown, the smooth rear wall 4 of another bag 1 ′ may be stacked on the upper surface of the front wall 3 of the bag 1 with the surface having the protrusion 9 facing downward. In that case, the rear wall 4 of the other bag 1 ′ is pulled by the weight of the contents, and the dead space generated between the inner surface of the wall 4 and the contents is reduced thereafter. Therefore, the protrusion 9 of the lower bag 1 tends to bite into the rear wall 4 of the upper bag 1 ′.

FIG. 2b is an enlarged cross-sectional view of the stacked portion of the upper and lower bags 1 'and 1 shown in FIG. 2a. A biting portion 4a is formed on the rear wall of the lower bag 1 by pressing the projection 9 of the upper bag 1 '. The biting portion 4a comes into close contact with the protrusion 9 by an elastic reaction force caused by being pushed away. If the rear wall 4 is thick and made of a soft material, the rear wall 4 is elastically deformed to form the biting portion 4a without pushing the contents as shown in the figure. The protrusion 9 of the upper bag 1 'protrudes outward, and a recess 9a is formed inside the protrusion.
Moreover, when it piles up as shown to this figure, the base vicinity of the processus | protrusion 9 is supported by the content, and the intensity | strength of the processus | protrusion 9 can be raised further. In particular, if the content is a fine powder, the content enters the recess 9a of the projection 9, and is integrated with the projection 9 to become a strength member (see arrow B).
On the other hand, when the front wall 3 is thick and formed of a soft material, the recess 9a inside the protrusion 9 is reduced and the strength of the protrusion 9 is increased. Therefore, it becomes easy to bite in. In this case, it is easy to bite in regardless of which of the projections 9 faces up and down.

The protrusion 9 has a substantially conical shape or a substantially cylindrical shape, and preferably has a shape that bites into the smooth surface of the rear wall 4 of the other bag 1 'to increase friction. The bite is deepened by increasing the load weight due to stacking, and further improves the anti-slip performance. The height at which the protrusion 9 protrudes from the surface of the front wall 3 is 0.2 to 0.4 mm, preferably 0.25 to 0.35 mm, and has a substantially diameter at a portion continuous with the surface of the front wall 3. Is 0.3 to 1.5 mm, preferably 0.5 to 1 mm. Then, the average density of the protrusions 9 is 15 to 30 / cm ^2, preferably 19 to 23 pieces / cm ^2, more preferably 20 to 22 pieces / cm ^2.

The contents to be packaged of the bag 1 of the present invention are powdered granular materials such as synthetic resin pellets, cement, grains, chemical products, fertilizers, and pet foods. The size of the granule is 0.003
-10 mm, preferably 0.15-4 mm.

FIG. 3 shows a method for manufacturing the bag 1 of the present invention. The manufacturing method 15 includes inflation processing 16 in which compressed air is blown into a tube that has been extruded and expanded to form a long and thin cylindrical member 15a, and the obtained cylindrical member is folded flat and printed on its surface. A printing process 17 for applying a step, and an embossing process 18 for expanding the printed flat member into a cylindrical shape again, and pressing the embossing roll outwardly from the cylindrical member to form a large number of protrusions. And a winding step 19 in which a cylindrical member with projections is folded flat and wound into a roll. Note that towns (gussets) corresponding to the left and right walls 7 and 8 of the bag 1 may be formed almost simultaneously with or before and after the embossing step 18.

  FIG. 4a shows how embossing is performed. FIG. 4b is a view of the front side of the tubular member 15a shown in FIG. The front side corresponds to the front wall 3 side of the bag 1. As shown in FIG. 4a, in the embossing step 18, the cylindrical member that has flowed from the printing step 17 (see FIG. 3) is expanded into a rectangular cross section, and the embossing device 11 ( The embossing is performed according to FIG.

  FIG. 5 shows an embossing apparatus. The embossing device 11 has a vertically long shape, and is formed so that the thickness in the front-rear direction is reduced below. Above the embossing device 11, a pair of rollers 11a are rotatably provided on the front and rear surfaces thereof. On the other hand, on the outside of the cylindrical member, support rollers 12a fixed to the frame 12 extending from the floor surface are rotatably provided in the front and rear of the embossing device 11 (see FIG. 4b). The embossing device 11 is in a suspended state. And in the site | part pinched in the state which interposed the cylindrical member, the roller 11a of the embossing apparatus 11 is arrange | positioned in the vicinity of the upper surface of the support rollers 12a and 12a.

  A pair of rubber rollers 12b and 12b are rotatably attached to the frame 12. The rubber rollers 12b and 12b are provided below and in parallel with the front and rear support rollers 12a and 12a, respectively. The embossing device 11 is provided with an embossing roller 13 provided with a large number of convex portions 13a. The embossing roller 13 and the rubber roller 12b sandwich the front side of the cylindrical member. And the convex part (not shown) of the said embossing roller 13 presses a cylindrical member from an inner surface, a cylindrical member is pressed against the surface of the rubber roller 12b, and the said protrusion 9 (refer FIG. 2b). It is formed.

On the other hand, on the rear side of the cylindrical member, the non-convex roller 14 (flat roller) sandwiches the rear side portion of the cylindrical member with the rear rubber roller 12b. In the drawing, two convex rollers 13 and two flat rollers 14 are arranged in series in the direction of the rotation axis, but one long roller may be used, or three or more rollers may be arranged in series. You may arrange in.
In addition, as a raw material of the convex roller 13 and the flat roller 14, there are iron, steel, stainless steel, aluminum, casting, hard plastic, wood, and the like.

  In addition, when embossing cannot be performed, the surface may be roughened, for example, and fine protrusions may be provided. Further, fine particles may be sprayed on the outer surface of the front wall 5 to roughen the surface to form protrusions. Further, a sheet or tape provided with a projection shape in advance may be attached to the outer surface of the front wall 5.

The protrusions 9 are arranged in a substantially strip shape extending in the vertical direction in a range excluding the vicinity of the left and right side edges of the outer surface of the front wall 5. Therefore, the longer the long side of the front wall 5 is, the larger the contact area in the vicinity of the center is and the anti-slip performance is improved. Further, the range where the projections 9 are formed may be the almost entire surface of the front wall 5 and the range where the pressure of the bag 1 is most applied. Further, a plurality of the belt-like parts may be provided, and the belt-like parts may be arranged at equal intervals. Then, even if the left and right sides of the bag 1 are reversed, the same slip resistance can be obtained. In addition, you may arrange | position so that it may not interfere with the printing of the surface of the front wall 5. FIG. Further, these protrusions 9 can be used as a pattern of the bag 1 to express a certain pattern integrally with the printing surface, for example.

  FIG. 6 shows the roll-shaped member obtained in the winding step 19. Reference numeral 20a in the figure is a core rod around which the member is wound. Further, there is a swollen portion 20b in the vicinity of the center of the roll-shaped member 20 obtained from the winding step 19. The swollen portion 20b is a portion that is bulky because the protrusion 9 is formed by embossing. Since the bag 1 of the present application has the protrusions 9 formed only on one side (front wall), the portion 20b is not bulky compared to the case where the protrusions formed by embossing are formed on both sides. Therefore, the number of turns can be increased. In other words, in a conventional flat body with irregularities formed on both sides, the central portion (projection) is bulky, so when it is rolled, the number of turns (winding length) cannot be increased, and the number of turns is also stable. There wasn't. For example, the conventional winding length with both sides embossed is 900 to 1200 m, but in the present application, it is about 1500 to 2000 m.

From here, the result of having compared the slip of the bag of the Example of this invention with the bag of a comparative example is shown. The bags used for measurement were Young's modulus MD2080 / TD2380 kg / cm ² (hereinafter referred to as sample 1) and Young's modulus MD2100 / TD2490 kg / cm ² (sample 2) as soft bags. Further, Young's modulus MD2140 / TD2470 kg / cm ² (Sample 3) and Young's modulus MD2220 / TD2820 kg / cm ² (Sample 4) were used as so-called general hardness bags. Furthermore, Young's modulus MD3250 / TD3670 kg / cm ² (Sample 5) was used as a hard bag.

  In the measurement, the test pieces of the two bags 1 and 1 'are stacked on an inclined table (not shown), the inclined table is inclined, and the inclination angle at which the slip occurs between the bags is measured. The measurement is performed five times, and an average value of three points excluding the maximum value and the minimum value is adopted as the measurement value. In addition, the five measurements are set as one set, and the average value of the three sets is compared with the other conditions as the angle at which the final slip occurs. In addition, all the unevenness | corrugations (protrusion) 9 are formed by embossing using the same type | mold. In the table, the top and bottom are the directions of the embossed surface. For example, if both the top and bottom are “Yes”, the upper and lower surfaces of one bag 1 have embossed projections 9 formed. , Such bags are stacked on a ramp. As an example, the suffix a is given to the projection only on the upper side, and the suffix b is given to the projection having the projection 9 only on the lower side. Further, as a comparative example, a suffix c is given to those having projections on both sides, and a suffix d is given to those having no projections on either side.

  Table 1 shows the measurement results of Sample 1. The thickness of the bag used is 150 μm. The temperature at the time of measurement was 24 ° and the humidity was 50%. It can be seen that in the embossing, Examples 1a and 1b formed on one side are more excellent in slip resistance than Comparative Example 1c than those formed on both sides.

  Table 2 shows the measurement results of Sample 2. The thickness of the bag used is 140 μm. The temperature at the time of measurement was 22 ° and the humidity was 17%. Similar to the results of Example 1, it can be seen that Examples 2a and 2b formed on one side are more effective in anti-slip than Comparative Example 2c.

  Table 3 shows the measurement result of Sample 3. The thickness of the bag used is 180 μm. The temperature at the time of measurement was 24 ° and the humidity was 50%. Here again, it can be seen that the embossing is more effective in anti-slip in Examples 3a and 3b formed on one side than in Comparative Example 3c. In addition, when the material of a bag becomes hard, there exists a tendency for it to be inferior compared with the case where anti-slip performance is slightly soft.

  Table 4 shows the measurement results of Sample 4. The thickness of the bag used is 140 μm. The temperature at the time of measurement was 22 ° and the humidity was 50%. It can be seen that embossing is more effective in anti-slip than the comparative example 4c in the examples 4a and 4b formed on one side as in the example 3.

  Table 5 shows the measurement results of Sample 5. The bag used has a thickness of 200 μm. The temperature at the time of measurement was 24 ° and the humidity was 50%. It can be seen that embossing is more effective in anti-slip properties in Examples 5a and 5b formed on one side than in Comparative Example 5c.

  The slip angle of the one having the embossed projection 9 on one side was about 39 to 44 °. On the other hand, the slip angle of the projections on both sides was about 30 to 33 °. In addition, what applied anti-skid liquid only to the upper surface of a paper bag was around 35 degrees, and what applied the upper and lower surfaces was around 37 degrees.

1 Bag for packing powder (bag)
2 Peripheral wall 2a Thermal welding (lower end)
2b Thermal welding (upper end)
3 Front wall 3a Band-shaped range 4 Rear wall 4a Biting portion 5 Top surface 6 Bottom surface 7 Left wall 8 Right wall 9 Protrusion 9a Depression 10 Pallet 11 Embossing device 11a Roller-shaped member 12 Frame 12a Support roller 12b Rubber roller 13 Embossing roller 13a Convex part 14 Convexless roller (Flat roller)
DESCRIPTION OF SYMBOLS 15 Manufacturing method 15a Cylindrical member 16 Inflation process 17 Printing process 18 Embossing process 19 Winding process 20 Roll-shaped member

Claims (6)

A bag for packaging of granular material comprising closed by bonding the faces thereof opposite the lower end of the cylindrical synthetic resin sheet formed by inflation process,
Has a front wall and a rear wall,
Its front wall, by embossing outwardly a site serving as Maekabe when the tubular sheet from the inside, a large number of projections projecting from the outer surface is formed,
The surface of the rear wall is formed smoothly,
A bag for packaging granular materials in which, when a plurality of bags are stacked, the protrusions of one bag bite into the smooth surface of the other bag to prevent slippage between the bags. In Young's modulus of the sheet ^{MD1000 / TD1500~MD3500 / TD4000kg / cm 2} , and a thickness is 0.1～0.23Mm,
The protrusion is formed with a depression by pressing inside thereof, and is formed in a substantially conical shape tapered outward on the opposite side of the depression,
The packaging of the granular material according to claim 1, wherein the height of the protrusion from the outer surface of the front wall is 0.2 to 0.4 mm, and the diameter of the bottom surface of the outer surface is 0.8 to 1.5 mm. Bags. The front wall and the rear wall have a substantially rectangular shape that is long in the vertical direction,
The bag for packaging granular materials according to claim 2, wherein the projections are arranged in a substantially strip shape extending in the vertical direction in a range excluding the vicinity of the left and right side edges of the outer surface of the front wall.   The bag for packaging granular materials according to claim 3, wherein a plurality of the band-shaped parts are provided, and the band-shaped parts are arranged rotationally symmetrically. A method for producing a bag for packaging powder according to any one of claims 1 to 4,
Inflation processing, in which compressed air is blown into an extruded tube to expand it, and is formed into an elongated cylindrical member;
The manufacturing method of the bag for the packaging of a granular material provided with the embossing process which presses an embossing roller outward from the inner side to the obtained cylindrical member, and forms many protrusions. The embossing is performed by an embossing device provided with the embossing roller,
The embossing device is vertically long and formed so that the thickness in the front-rear direction is thin at the bottom, rollers are provided on the front and back surfaces above it, and are housed inside the cylindrical member,
The granular material packaging according to claim 5, wherein the roller has a cylindrical member interposed therebetween, the cylindrical member is sandwiched by a support roller fixed to the frame, and the embossing apparatus is suspended. Manufacturing method for the bag.

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