JP3130185U - Square bottom bag - Google Patents

Abstract

Provided is a square bottom bag which can effectively prevent liquid intrusion and liquid leakage by securely sealing the square bottom portion and can easily maintain the shape of the corner bottom portion.
A square bottom part 4 is a rectangular tube made of a single sheet, and a first seal part S1, a second seal part S2, and a third seal that are thermocompression-bonded along the axial center of the bottom part 4b. Part S3. The first seal portion S1 is formed by sealing the wide surface 3 and the bottom of the narrow surface 2 folded on the wide surface 3 on the left and right sides of the wide surface 3 while providing a margin S ′. The second seal portion S2 is obtained by sealing the belt margin S ′ provided by the first seal portion S1 with respect to the bottom portion 4b. The third seal portion S3 is a short side of the corner bottom portion 4 that is in a direction perpendicular to the first seal portion S1 and the second seal portion S2 in the vicinity of the boundary portion between the corner bottom portion 4 and the narrow surface 2. The bottom portion 4b and the triangular portion 4a are sealed in the direction.
[Selection] Figure 1

Description

  The present invention relates to a square bottom bag having a rectangular bottom for packaging or storing articles, and more particularly to a technique capable of maintaining the square shape of the bottom.

  2. Description of the Related Art Conventionally, square bottom bags have been widely used as products for packaging or storing products in department stores or the like. These types of square-bottom bags are prepared for each retail store, and each store has its own design, so the image of the store, the quality of products handled, the quality of services, etc. It plays an important role of indexing. Moreover, since the goods to be stored are diverse, such as food, clothing, books, and ceramics, the corresponding durability and waterproofness are required.

  In order to meet such demands, conventionally, square bottom bags with various ideas have been proposed. For example, as shown in FIG. 4, in a square bottom bag 10 composed of a narrow narrow surface 2 constituting the side surface portion of the bag and a wide wide surface 3 constituting the front back portion of the bag, A square bottom bag has been proposed in which the bottom portion is sealed with the narrow surface 2 folded (see Patent Document 1). In this square bottom bag, the lower end portion of the overlapping narrow surface 2 is cut out by folding inside, and the lower end portion of the square bottom bag including the overlapping portion is heat-sealed, so that it corresponds to the notch among the portions that are not folded. The part that does not overlap and the part that does not overlap and overlap each other forms a strong seal S of two layers in the lateral direction, and closes the lower end part to prevent liquid leakage and the like.

Also, as shown in FIG. 5, the narrow surface 2 side and the wide surface 3 side of the square bottom portion of the square bottom bag 20 are folded inward, and the opposite ends of the square bottom portions 4d on the wide surface 3 side overlap each other. A portion heat seal S3 (horizontal seal) is performed, and further, a heat seal S4 (vertical seal) is formed at the portion of the square bottom portion 4d on the wide surface 3 side and the trapezoidal portion 4c on the narrow surface 2 side that overlaps the surface of the bag. is doing. Thus, by sealing a total of four places with the horizontal seal and the vertical seal, the bottom of the corner is sealed, and the intrusion and leakage of liquid such as water from there are prevented (see Patent Document 2).
Japanese Utility Model Sho 55-66945 Utility model registration No. 3084348

  However, the conventional techniques have the following problems. That is, with the technique disclosed in Patent Document 1, it cannot be said that the square bottom 4 is sufficiently sealed (see FIG. 4). That is, when the square base 4 is opened, the triangular portion 4a at the lower portion of the narrow surface 2 is not fixed to the bottom 4b, so that the strength of the apex portion P of the triangular portion 4a is weak and the seal is slightly displaced. For example, there is a possibility that a hole is formed in this apex portion, and there are problems in durability and waterproofness.

  Further, for example, when an article having a cross-sectional area smaller than that of the bag or a non-square article is stored in the square bottom bag 10, the bottom portion 4b and the triangular portion 4a are not fixed. 4b and the triangular part 4a peeled off, and it was difficult to keep the box shape of the square bottom as it was.

  On the other hand, in the technique of Patent Document 2, since two vertical and horizontal positions are sealed, there is a low possibility that such a hole is generated. However, as a manufacturing method thereof, a cut bag must be fitted into a mold having the same shape as the bag, and then the wide surface 3 and the narrow surface 2 are folded, respectively, and further sealed in two places, for a total of four places. Therefore, the work process is complicated and it is difficult to improve productivity.

  The present invention has been proposed in order to solve the above-described problems of the prior art, and its purpose is to effectively prevent liquid intrusion and liquid leakage by securely sealing the bottom of the corner. An object of the present invention is to provide a square bottom bag that can be prevented and that can easily maintain the shape of the square bottom portion.

  In order to solve the problems as described above, in the square bottom bag according to claim 1, one sheet has a pair of opposed narrow surfaces and a pair of opposed wide surfaces arranged orthogonal to each other. A cylindrical body is formed by folding the pair of narrow surfaces inside the cylindrical body at an axial center position so that the pair of wide surfaces are in contact with each other. A corner provided with a narrow bottom surface and a wide surface sealed at the axial end portion of the cylindrical body over the entire width, and a square bottom portion that is opened in a bilaterally symmetric shape around the sealed end portion. In the bottom bag, the square bottom portion is formed by a part of the wide surface and forms a bottom surface of the square bottom bag, and is formed by a part of the narrow surface and is folded in a triangular shape on the inner bottom surface of the square bottom bag. A band is provided at the end in the axial direction. A first seal portion that is sealed, a second seal portion that seals the end of the band with respect to the bottom portion, and the vicinity of the boundary between the bottom portion, the triangular portion, and the pair of narrow surfaces, And a third seal portion sealed substantially parallel to the narrow surface.

  In the above aspect, since the band is crimped to the corner bottom portion by the second seal portion, the corner bottom portion is prevented from being bent from the first seal portion, and the band margin is obstructive at the corner bottom portion. Nor. The end of the cylindrical body is sealed by the first seal portion in a state where a band is provided, and the band is pressed against the square bottom by the second seal portion. In the past, since the band was not crimped, the bottom of the corner was easy to break into two around the first seal part, and it was difficult to keep the bottom of the flat, but this invention solves this problem. ing.

  In conventional square-bottom bags, a load is placed on the corner bottom when an object is stored, and in particular, the addition is concentrated on the part that crimps the bottom of the narrow surface and the bottom of the wide surface. However, in the square bag of the present invention, the narrow end and the wide surface are securely sealed at the center that divides the area of the triangular portion into two by sealing the front end of the band with the second seal portion. can do. Therefore, for example, a hole is not formed between the narrow surface bottom portion and the wide surface bottom portion, and the waterproofness and durability of the bag can be maintained high.

  In addition, the corner bottom portion is formed by overlapping a pair of wide surfaces, and is further crimped twice by the first seal portion and the second seal portion. The center position of the bottom portion is reinforced, and the shape collapse of the corner bottom portion can be suppressed.

  Further, the third seal portion presses between the bottom portion and the triangular portion in the vicinity of the boundary portion between the corner bottom portion and the narrow surface in substantially parallel to the narrow surface, so that the liquid from the short side direction of the corner bottom portion can be reduced. Infiltration and liquid leakage can be prevented. Furthermore, in the short side direction of the corner bottom part, the crimped line is reinforced as if the core material is inserted, and the shape collapse of the corner bottom part in the short side direction can be suppressed.

  Thus, in this invention, by providing three seal parts, a 1st seal part, a 2nd seal part, and a 3rd seal part, a narrow surface and a wide surface, and a bottom part and a triangle part formed from these Is securely sealed, and the waterproofness and durability of the bag can be maintained high. Further, in order to reinforce the center position of the corner bottom portion by the first seal portion and the second seal portion and the boundary portion with the narrow surface of the corner bottom portion by the third seal portion as if the core material was inserted, It is possible to flatten the bottom and maintain the shape.

The invention of claim 2 is characterized in that, in the invention of claim 1, the sheet is made of polyethylene, and the first, second, and third seal portions are thermocompression-bonded by melting the polyethylene by heat. To do.
In the above aspect, the sheet is formed of polyethylene, and the sealing portion is configured by thermocompression bonding, thereby improving the waterproofness and water resistance of the square bottom bag, as compared with the case of sealing using an adhesive or the like, Square bottom bags can be manufactured inexpensively and easily, and productivity can be improved.

The invention of claim 3 is characterized in that, in the invention of claim 1 or 2, a pair of hand-holding portions are provided at ends of the pair of wide surfaces opposite to the square bottom portions in the cylindrical body axis direction. To do.
In the above aspect, by providing the hand-held portion, it is easy to carry the square bottom bag.

  As described above, according to the present invention, by securely sealing the bottom of the corner, it is possible to effectively prevent the intrusion of liquid and the leakage of the liquid and to provide a square bottom bag that can easily maintain the shape of the corner bottom. can do.

  Next, the best mode for carrying out the present invention (referred to as the present embodiment) will be described with reference to the drawings. In addition, in embodiment described below, as a material of the square bottom bag 1, from the viewpoint of waterproofness and durability, what uses polyethylene is assumed, and it is assumed that the seal part is thermocompression bonded. However, the present invention is not limited to such an embodiment. That is, any material can be applied as long as it is conventionally used as a square bottom bag, such as paper or cloth. Also, the sealing method of the seal portion is not limited to the method of melting and crimping by heat, and may be a method of crimping or sewing using an adhesive.

  FIG. 1 shows a state in which the bottom portion of the bottom bag 1 in the present embodiment is opened. The square bottom bag 1 has a rectangular tube shape made of a single sheet, and has a pair of opposing narrow surfaces 2 having a folding line F that is folded in the axial direction at the center in the axial direction, and a direction perpendicular to the narrow surface 2. It consists of a pair of wide surfaces 3 provided with two surfaces facing each other, and a corner bottom 4 formed by folding the narrow surface 2 and the wide surface 3.

  The square bottom part 4 is formed by a part of the wide surface 3 and is formed in a triangular shape on the bottom part 4b constituting the bottom surface of the square bottom bag 1 and the inner bottom surface of the square bottom bag 1 formed by a part of the narrow surface 2. And a triangular portion 4a (shown by a broken line in the figure). As shown in FIG. 2, the triangular portion 4 a is configured to be double so that the surface X that is in contact with the bottom 4 b and the surface Y that is not in contact with each other overlap.

  The square bottom portion 4 is sealed by thermocompression along the center of the bottom portion 4b in the major axis direction, and the seal portions include the first seal portion S1, the second seal portion S2, and the third seal portion S3. It consists of.

  As shown in FIG. 2 (a), the first seal portion S1 is provided with a wide surface 3 and a margin S ′ covering the ends of the narrow surface 2 that is convoluted to the wide surface 3 on the left and right sides of the wide surface 3. However, it is sealed in a band shape. 2A is a view showing a state in which only the first seal portion S1 is applied to the square bottom portion bag 1, and FIG. 2B shows the second seal portion 2 in addition to the first seal portion S1. It is the figure which showed the state which gave 3rd seal | sticker part S2, S3.

  As shown in FIG. 2B, the second seal portion S2 is obtained by sealing the band margin S 'provided by the first seal portion S1 with respect to the bottom portion 4b. Further, the third seal portion S3 is a short portion of the square bottom portion 4 which is a direction orthogonal to the first seal portion S1 and the second seal portion S2 in the vicinity of the boundary portion between the square bottom portion 4 and the narrow surface 2. The surface X and the surface Y between the bottom portion 4b and the triangular portion 4a are sealed in the side direction.

  In addition, although the handbag part 5 of the square bottom bag 1 is also described in drawing, this is not an essential component in this invention but arbitrary things. Therefore, the handbag portion 5 may or may not be provided in the square bottom bag 1 of the present embodiment, and when it is used, any aspect can be adopted as long as it is a known handbag.

  Next, the manufacturing procedure of the square bottom bag 1 which consists of such a structure is demonstrated. First, at the stage shown in FIG. 3A, the corner bottom 4 is not formed. That is, the bag 1 before being cut is continuously fed in a band shape with the narrow surface 2 being folded inside the sheet of the cylindrical body along the folding line F at the center in the axial direction. And each bag is cut | disconnected and isolate | separated for every length L set according to a use and the objective from this belt | band | zone. At this time, at the boundary between the lower end portion and the upper end portion of each bag 1, the wide surface and the folded narrow surface are thermocompression bonded to form the first seal portion S1. At this time, a margin S 'is formed at the tip of the first seal portion S1.

  Next, as shown in FIG. 3B, the separated square bottom bag 1 is fitted into a mold C having the same size as this bag. At this time, as described above, since the first seal portion S1 is formed in a state in which the narrow surface 2 is folded, one end portions of the narrow surface 2 and the wide surface 3 are sealed. Therefore, when fitted in a mold C equivalent to the size of the bag 1, as shown in FIG. 5C, the bottom 4 b that can be formed by folding the wide surface 3 to form the square bottom 4, and the narrow A triangular portion 4a is formed by folding the surface (indicated by a dashed line in the figure). Here, the triangular portion 4a is formed by doubled two surfaces, a surface that contacts the bottom portion 4b and a surface that does not contact the bottom portion 4b. At this stage, the triangular portion 4a is separated as shown in the figure.

  In addition, this type | mold C is only a mere illustration in this embodiment, and when it acts so that the folded square bottom bag 1 may be opened when forming the following 2nd seal | sticker part, any structure It doesn't matter.

  In this state, as shown in FIG. 3 (d), the distal end portion of the band S ′ formed by the first seal portion S1 is thermocompression bonded so as to sandwich the triangular portion 3a and the bottom portion 4b, and the second portion The seal portion S2 is formed. Since the second seal portion S2 is formed with the square bottom portion 4 open, the band S ′, the triangular portion 4a, and the bottom portion 4b are sealed at the same time, and the belt margin S ′ is sealed with respect to the bottom portion 4b. In addition, the surfaces X and Y formed on the triangular portion 4 a are thermocompression bonded at the center position in the long side direction of the square bottom portion 4. That is, by sealing the front end of the band S ′, as shown in FIG. 3D, the surface Y and the surface X or the bottom 4b are bonded together at the center that bisects the area of the triangular portion 4a. The Rukoto.

  Next, as shown in FIG. 3 (e), in the vicinity of the boundary portion between the bottom surface 4 and the narrow surface 2, an angle that is perpendicular to the first seal portion S1 and the second seal portion S2. The surface X and the surface Y between the bottom portion 4b and the triangular portion 4a are sealed along the short side direction of the bottom portion 4. Thereby, the third seal portion S3 is formed.

  The square bottom bag of this embodiment manufactured as described above can crimp the bottom portion 4b by the first seal portion S1, and further crimp the surface X, the surface Y, and the bottom portion 4b by the second seal portion S2. be able to. Further, the third seal portion S3 can press-bond the bottom portion 4b in the vicinity of the boundary portion between the corner bottom portion 4 and the narrow surface 2 and the triangular portion 4a toward the short side of the corner bottom portion 4. As a result, the following remarkable effects can be obtained.

  That is, since the band margin S ′ formed by the first seal portion S1 can be pressure-bonded to the corner bottom portion 4 by the second seal portion S2, the corner bottom portion is bent from the first seal portion S1. In addition, the band margin does not get in the way at the bottom of the corner. The end portion of the cylindrical body is sealed with the band margin S ′ by the first seal portion S <b> 1, and the band margin S ′ is pressure-bonded to the square bottom portion 4 by the second seal portion S <b> 2. In the past, since the band was not crimped, the bottom of the corner was easy to break into two around the first seal part, and it was difficult to keep the bottom of the flat, but this invention solves this problem. ing.

  In conventional square-bottom bags, a load is placed on the corner bottom when an object is stored, and in particular, the addition is concentrated on the part that crimps the bottom of the narrow surface and the bottom of the wide surface. However, in the square bottom bag 1 of the present embodiment, by sealing the front end of the band S ′ with the second seal portion S2, the surface Y and The surface X or the bottom portion 4b is pressure-bonded together, and the narrow surface bottom portion and the wide surface bottom portion can be reliably sealed. Therefore, for example, a hole is not formed between the narrow surface bottom portion and the wide surface bottom portion, and the waterproofness and durability of the bag can be maintained high.

  In addition, the square bottom 1 is formed by stacking a pair of wide surfaces 3 and further crimping the core with the first seal portion S1 and the second seal portion S2 twice. As inserted, the center position of the square bottom part 4 is reinforced, and it is possible to suppress the collapse of the box shape of the square bottom part 4.

  Furthermore, the third seal portion S3 is used to press the gap between the bottom portion 4b and the triangular portion 4a in the vicinity of the boundary portion between the corner bottom portion 4 and the narrow surface 2 in substantially parallel to the narrow surface 2, thereby It is possible to prevent liquid intrusion and liquid leakage from the short side direction. Further, in the short side direction of the square bottom portion 4, the crimped line is reinforced as a core material is inserted, and the shape collapse of the square bottom portion 4 in the short side direction can be suppressed.

  As described above, the square bottom bag 1 of the present embodiment includes the three seal portions of the first seal portion, the second seal portion, and the third seal portion, thereby forming the narrow surface and the wide surface. The bottom portion and the triangular portion are securely sealed, and the waterproofness and durability of the bag can be maintained high. Further, in order to reinforce the center position of the corner bottom portion by the first seal portion and the second seal portion and the boundary portion with the narrow surface of the corner bottom portion by the third seal portion as if the core material was inserted, It is possible to flatten the bottom and maintain the shape.

  Furthermore, in the conventional square-bottom bag, in order to keep the square-bottom part sealed, after cutting each bag from the belt that is continuously fed in the manufacturing process, the narrow and wide surfaces of the cylindrical bag are folded and folded. In the square bottom bag 1 according to the present embodiment, the first seal portion S1 is used when the continuously fed belt-like sheet is cut into each bag. Therefore, it is not necessary to fold the wide surface 3 and the narrow surface 2 thereafter, and the square bottom 4 can be formed simply by fitting into the mold C. Further, it is possible to ensure the sealing of the corner bottom by simply sealing the second and third seal portions in this state. Therefore, it is possible to remarkably improve productivity as compared with the conventional case.

The perspective view which shows the structure of the square bottom bag which concerns on embodiment of this invention. The enlarged view which shows the structure of the square bottom part of the square bottom bag which concerns on embodiment of this invention. The perspective view which shows the manufacture procedure of the square bottom bag which concerns on embodiment of this invention. The perspective view which shows the structure of the conventional square bottom bag. The perspective view which shows the structure of the conventional square bottom bag. The enlarged view which shows the structure of the conventional square bottom bag.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Square bottom bag 2 ... Narrow surface 3 ... Wide surface 4 ... Square bottom part 4a ... Triangle part 4b ... Bottom part 5 ... Hand-carrying part C ... Folding line P ... Vertex S1 ... 1st seal | sticker part S2 ... 2nd seal | sticker Part S3 ... Third seal part X, Y ... surface

Claims (3)

One sheet forms a cylindrical body by arranging a pair of opposing narrow surfaces and a pair of opposing wide surfaces orthogonal to each other,
The narrow surface and a part of the wide surface are formed, and the pair of narrow surfaces are folded inside the cylindrical body at the axial center so that the pair of wide surfaces are in contact with each other. In a square bag with a square bottom formed by sealing across the entire width at the axial end of the cylindrical body, and a square bottom that opens in a bilaterally symmetric shape around the sealed end,
The corner bottom is
The bottom portion that is formed by a part of the wide surface and constitutes the bottom surface of the square bottom bag, and the triangular portion that is formed by a part of the narrow surface and is folded in a triangular shape on the inner bottom surface of the square bottom bag,
A first seal portion sealed with a margin at the axial end;
A second seal portion that seals the end of the band with respect to the bottom;
A third seal portion that seals the vicinity of the boundary between the bottom portion and the triangular portion and the pair of narrow surfaces substantially parallel to the narrow surface;
A square bottom bag characterized by comprising: The sheet is made of polyethylene;
The square bottom bag according to claim 1, wherein the first, second, and third sealing portions are obtained by melting the polyethylene by heat and thermocompression bonding.   The square bottom bag according to claim 1 or 2, wherein a pair of handbags are provided at ends of the pair of wide surfaces opposite to the square bottom portions in the cylindrical body axial direction.

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