Paper bag with bottom gusset

Abstract

To provide a flat paper bag having a gusset at the bottom and capable of being easily manufactured at low cost by an automatic bag making machine. [Solution] The bag comprises a main body 2 formed by gluing oppositely extending edges across a fold 4 of a folded piece of paper 3. The inner surface of the main body 2 is provided with a pair of lines 5a, 5b, each of which is connected to both ends of the fold 4 and extends convexly on either side of the fold 4. When the fold 4 of the bag 1 is pressed toward the inside of the bag 1 with the fingers, the fold 4 unfolds and simultaneously the bottom of the bag 1 bends inward along the lines 5a, 5b, forming a gusset.

Description

[Technical Field]

[0001] The present invention relates to a flat paper bag, and more particularly to a flat paper bag having a gusset at the bottom. [Background technology]

[0002] Paper flat bags generally consist of a pair of overlapping pieces of paper glued together at the edges on both sides and at one end, and have the advantage of being easily and inexpensively manufactured using an automatic bag-making machine.However, they have the disadvantage that the bags do not have gussets and cannot properly store thick items (see, for example, Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 7-2077 Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, an object of the present invention is to provide a flat paper bag with a gusset that can be easily manufactured using an automatic bag making machine. [Means for solving the problem]

[0005] In order to solve the above problems, the present invention provides a paper flat bag having a body made of two folded sheets of paper with edges that extend opposite each other and are glued together across the fold, and characterized in that the inner surface of the body has a pair of lines that are convex on both sides of the fold and each end of the body is connected to both ends of the fold.

[0006] According to a preferred embodiment of the present invention, the pair of creases are formed in the shape of a pair of arcs that are symmetrical with respect to the fold line.

[0007] According to another preferred embodiment of the present invention, the creases are formed by a Thompson process.

[0008] According to yet another preferred embodiment of the present invention, the thickness of the paper is 52.3 g / m 2 ~209.3g / m 2 It is preferable that:

[0009] In addition, even if paperboard is used instead of general paper, a paper flat bag with a bottom gusset can be formed in the same manner. In this case, the thickness of the paperboard is 160 g / m 2 ~450g / m 2 It is preferable that: [Effects of the Invention]

[0010] According to the present invention, when the fold at the bottom of the paper bag is pressed toward the inside of the paper bag with the fingers, the fold spreads and the bottom part is bent inward along the crease and concaves, easily forming a gusset.

[0011] To manufacture this paper bag, it is only necessary to make a pair of creases at the same time as creating a fold in the normal paper bag manufacturing process, and therefore paper bags with a gusset at the bottom can be manufactured easily and at low cost using an automatic bag making machine. [Brief explanation of the drawings]

[0012] [Figure 1] (A) is an oblique view of a bottom gusseted paper bag according to one embodiment of the present invention, (B) is an oblique view of the bottom gusseted paper bag of (A) seen from the bottom side, and (C) is a side view of the bottom gusseted paper bag of (A) with the bottom gusset folded. [Figure 2] 2A is a development view of the flat bottom gusseted paper bag of FIG. 1, and (B) and (C) are development views of modified examples of the flat bottom gusseted paper bag of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, the configuration of the present invention will be described based on a preferred embodiment with reference to the accompanying drawings.

[0014] Fig. 1(A) is a perspective view of a flat bottom gusseted paper bag according to one embodiment of the present invention, Fig. 1(B) is a perspective view of the flat bottom gusseted paper bag of Fig. 1(A) seen from the bottom side, Fig. 1(C) is a side view of the flat bottom gusseted paper bag of Fig. 1(A) with the bottom gusset folded, and Fig. 2(A) is a development view of the flat bottom gusseted paper bag of Fig. 1.

[0015] As shown in Figures 1(A) to (C) and Figure 2(A), the flat paper bag 1 with a bottom gusset of the present invention has a main body 2, and the main body 2 is made up of edges 3a, 3b; 3c, 3d that extend opposite each other across the fold 4 of a folded piece of paper 3 and are glued together.

[0016] In this case, paper 3 is 52.3 g / m 2 ~209.3g / m 2 It is preferable that the thickness of the film is 100 μm or less.

[0017] Furthermore, on the inner surface of the main body 2, a pair of convexly curved lines 5a, 5b are provided on both sides of the fold 4, with both ends of each line connecting to both ends of the fold 4, respectively.

[0018] As is clear from FIG. 2(A), the pair of lines 5a, 5b are formed in the shape of a pair of arcs that are line-symmetrical with respect to the fold 4.

[0019] The pair of creases 5a, 5b are preferably formed simultaneously with the fold 4 by Thomson processing in the manufacturing process of the flat paper bag 1 with a bottom gusset.

[0020] The shape of the pair of lines 5a, 5b is not limited to this embodiment, and may be any shape as long as both ends of each line are connected to both ends of the fold 4 and extend convexly on both sides of the fold 4.

[0021] FIGS. 2(B) and (C) show modified examples of the pair of lines 5a and 5b. As shown in FIGS. 2(A) and 2(B), in this modification, the pair of lines 5a', 5b'; 5a" and 5b" are made up of broken lines.

[0022] According to the present invention, when the fold 4 at the bottom of the gusseted paper bag 1 is pressed with fingers toward the inside of the gusseted paper bag 1, the fold 4 spreads and at the same time the bottom part is bent inward along the lines 5a and 5b and recessed, easily forming a gusset.

[0023] To manufacture this flat paper bag 1 with a bottom gusset, it is only necessary to make a pair of lines 5a, 5b at the same time as the fold 4 in the process of manufacturing a flat paper bag using a normal automatic bag making machine.Therefore, the flat paper bag 1 with a gusset at the bottom can be manufactured easily and at low cost using an automatic bag making machine.

[0024] The configuration of the present invention has been described above based on a preferred embodiment, but it goes without saying that the configuration of the present invention is not limited to the above embodiment, and that those skilled in the art can devise various modifications within the scope of the configuration described in the appended claims.

[0025] For example, a paper bag with a bottom gusset can be formed in the same manner using paperboard instead of ordinary paper. In this case, the thickness of the paperboard is 160 g / m 2 ~450g / m 2 It is preferable that: [Explanation of symbols]

[0026] 1. Paper bag with bottom gusset 2 Main unit 3 Paper 3a~3d Margin 4. Fold 5a, 5b lines 5a', 5b' lines 5a“, 5b” ruled

Claims

1. a main body having oppositely extending edges glued together across the fold of the folded paper; The flat paper bag with a bottom gusset is characterized in that the inner surface of the main body has a pair of creases, each of which has both ends connected to both ends of the fold and extends convexly on both sides of the fold.

2. 2. The flat paper bag with a bottom gusset according to claim 1, wherein the pair of creases are formed in a pair of arcs that are line-symmetrical with respect to the fold.

3. 2. The flat paper bag with a bottom gusset according to claim 1, wherein the creases are formed by Thomson processing.

Images