JPH088995Y2 - Folding soft plastic container - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application This invention mainly relates to a soft plastic container for containing liquid food, industrial chemicals, agricultural chemicals, etc., and when storing the contents, an outer box such as a cardboard box. The present invention relates to a container that is put in a container and folded when not housed for storage and transportation.

(B) Prior art As described above, the plastic container with the corrugated cardboard outer box uses a soft synthetic resin such as polyethylene, polypropylene, vinyl chloride or the like or a composite material thereof as a material for the plastic inner bag, and utilizes each characteristic thereof. Various food products such as vinegar, soy sauce, milk, liquor, etc., or various industrial chemicals such as acids, organic and inorganic chemicals, photographic chemicals, adhesives, etc., or various agricultural chemicals such as liquid fertilizers, pesticides, soil coagulation. It is used for the transportation of a large number of liquids such as agents, and these composite containers can use inner bag materials suitable for various contents, are strong against vibration and impact, and are lightweight, Since both the bag and the outer box are foldable, they have the advantage that they can be made small after use and help save costs for returning, storing, and transporting, and are widely adopted.

However, the conventional composite container composed of the outer box and the inner bag, particularly the inner bag, has the following drawbacks to be improved.

(C) Problems to be solved by the invention In the case of the conventional inner bag, the unevenness of the wall thickness in the above-mentioned part (zone) that is inevitably generated at the time of forming the bag body, and the difference in strength and the folding back due to this The occurrence of irregularities in the curvature of the part was not particularly considered. As a result,
When transporting in a state of being inverted and folded when empty, as shown in Fig. 4 (a ') [comparative example], the outer surface of the bent portion (convex) is scratched, which causes There is a drawback that when the bag is filled with a liquid during use and a tension is applied to the inner bag, a breakage accident may occur.

As another phenomenon, the curvature of the bent portion becomes irregular due to the irregularity of the thickness of the container material at the bent portion and the unevenness of the bending rigidity based on it, and when this is folded, FIG. 5 (b) [Comparative Example] ] Deformation and protrusion points (20) are formed, and once such a habit is attached, irregular deformation is repeated in this local area at all times, and material fatigue and scratches concentrate, and the container from this point It was also the cause of breakage or liquid leakage.

The present invention solves the above-mentioned problems that have not been taken into consideration in conventional containers and improves the structure of the inner bag to prevent scratches and protrusions during folding and improve its strength and durability. The purpose is to devise a container that can prevent accidents and other problems, and this has been solved by the means described below.

(D) Means and Actions for Solving Problems The above-mentioned object can be solved by the following constitution of the bag body.

Generally, in a container having such a structure, a characteristic of the molding method is that the flat plate (or parison) is molded by blow molding or vacuum, so that the thickness should be uniform in all parts. Is difficult,
Occurrence of partial thickness is inevitable.

For example, FIG. 2 illustrates an inner bag obtained by the blow molding method. (A) is an overall view before folding, but in the case of a container obtained by such a manufacturing method, it is shown in the figure (A). , (B), (C), etc., have different thicknesses, and in the case of an ordinary blow molding method, the thickness t
Indicates the relationship of t (A)> t (B)> t (C), and each intermediate zone has an intermediate thickness of each respective zone.

In the case of the conventional inner bag, the differences in thickness, ie, strength and curvature in these different zones were not considered.

On the other hand, the inventors of the present invention consider that the occurrence of such partial thickness and thinness is unavoidable due to the manufacturing method, and after taking this into consideration, the parties in the zones having different thicknesses are considered. Table 1 shows the distance (X) between the center line (6) of the ridgeline (2) and the center line (5) of the arc-shaped ridge (3), and the height (Y) of the ridge (3). By making design adjustments to satisfy the relationships shown, smooth folding of the inner bag and elimination of irregularities in bending rigidity were achieved, and as a result, improvement in breakage prevention could be achieved.

Controlling such a relationship between X and Y seems complicated at first glance, but the position of the groove (X) provided on the inner surface of the mold on the folding inner layer side,
And the depth (Y) are designed and manufactured so as to satisfy the relationship shown in Table 1, and can be easily and accurately dealt with when the subsequent blow molding or vacuum molding is performed. The ridges can be provided at predetermined positions and shapes of the inner bag.

That is, as shown in FIGS. 2 (b) A zone, (c) B zone, and (d) C zone, which are enlarged sectional views of each zone shown in FIG. 2 (a), the ridges (3) of each zone are shown. Center line of (5)
The distance (X) between the center line (6) of the parting line (2) and the parting line (2) is shortened at the thin portion (C) of the inner bag (Fig. 2, c) and lengthened at the thick portion (A) (Fig. 2.
Along with b), the height (Y) of the ridge is reduced at a thin portion of the inner bag and increased at a thick portion of the inner bag.

The specifications of the container according to the present invention will be further extended.

As the soft plastic container which is the inner bag of the composite container as described above, a molded product molded by a method such as blow molding or vacuum molding is used, and two isosceles triangular columnar shells whose top sides are substantially right angles are used. It is a rectangular parallelepiped (or cube) obtained by welding with the bottoms facing each other and projecting four edges outward.

In this way, the parting line is formed in the process in which the folded outer layer and the inner layer are welded, and the two inner and outer layer parts are welded, so it is thicker than the other parts (face parts) of the bag,
High rigidity. Therefore, when the bag structure is set to the above conditions, it bulges firmly outward when folded, and protects the convex ridge surface provided at a predetermined interval (X) along it, and scratches can occur. In addition to the function to prevent this, it also has the function of a rectangular reinforcing frame formed on the diagonal of the cube.

For this reason, the parting line itself not only protects the ridges, but also reinforces the strength of the bag when it is filled with liquid and the strength of the part that facilitates handling when folding. It may also be referred to as a rib.

Such a container is stored in an outer cardboard box for storage and transportation when it is in the shape of a swelled straight (or cubic) cube when it is actually used, and when it is empty after use, it corresponds to one triangular prism body [folding inner layer (12) ] To other triangular prism equivalent parts [folding outer layer (1
(1) Inside] and fold, [[Fig. 1 (b)]] inserted to reduce the bulk, and many sheets are returned in the outer box (21) (Fig. 3) for repeated reuse. It will be possible.

The container according to the present invention could withstand long-time specifications without any problems.

(Example) For example, in the case of an inner bag having a capacity of 20 liters (outer box 297 x 297 x (h) mm) obtained by the blow molding method, A zone (X
= 5.0 ± 0.1mm, Y = 1.2mm), B zone (X = 4.0 ± 0.1mm, Y
= 1.2 mm), C zone (X = 4.0 ± 0.1 mm, Y = 1.0 mm),
In the middle area of each zone, the bending rigidity can be equalized by gradually increasing or decreasing the value in the middle of each zone according to the thickness. The relationships described above are summarized in Table 1 for easy understanding.

It should be noted that the mold on the folding inner layer side was previously provided with a groove satisfying the above relationship, and the mold on the folding outer layer side was not provided with a groove. Or, when performing blow molding from a parison, the inner bag having the above specifications can be mass-produced accurately and easily.

The numbers in the table are one example showing the embodiment,
The characteristic of the present application is shown not by the absolute value of the numerical value but by the relative relationship thereof.

As can be seen from the above embodiment, the present invention has the following features.

(1) When the container is folded and stored in the outer box (21) (cardboard box, etc.) before use and after use (FIG. 3), it is immediately When XY is too large, as shown in Fig. 4 (a ') (comparative example), the tip of the ridge, which is the bent part, protrudes from the parting line, and the tip of the ridge protects the parting line. It becomes difficult to receive it, and it contacts the outer box, causing scratches, cracks at folding points, or uneven deformation of the folded part [Fig. 5 (b) 20] (comparative example), etc. When the liquid is filled in the container (Fig. 1a), unexpected container damage or liquid leakage may occur.

However, by adopting the configuration of the present invention, the position of the ridge is regulated as shown in FIGS. 5 (c), (d), (e), and (f) [Example], and only the tip of the parting line is placed in the outer box. Since they come into contact with each other, the outer surface of the container is not scratched, and damage accidents can be prevented.

(2) Since the thick portion of the container has a large bending rigidity, the bending portion has a large curvature, while the thin portion has a small curvature. Therefore, long (X) and high (Y) near the thick portion and short (X) and low (Y) near the thin portion are suitable, and therefore the effect of (1) above is exhibited by the configuration of Table 1. .

(3) The container wall thickness on the side and front of the container is t (A)>
In the case of t (B)> t (C), by setting the relationship of X and Y as shown in Table 1, there is a tendency that the thickness of the bent portion becomes uniform, and the bending is smooth and clean. As a result, it is possible to prevent the occurrence of the protrusion-like deformation as shown in Fig. 5 (b ・ 20) due to the non-uniformity, and it is possible to prevent the damage accident of the container due to this cause.

(4) In summary, t (A), t (B), t (C), and X, Y
As long as it keeps the relative relationship of the present application, scratches with the outer box,
It is possible to prevent the generation of deformed protrusions and prevent accidental breakage of the container (bag).

(E) Effect of the Invention This invention is a butt joint part of two isosceles triangular columnar shells having an apex angle of substantially right angle, obtained by a molding method such as blow molding, vacuum molding, etc., with their bottom surfaces facing each other. A rectangular (or cubic) cube obtained by welding the surroundings in a state where both are convex toward the outside, and one triangular columnar shell equivalent part (folding inner layer) and another triangular columnar shell equivalent part (folding outer layer ) In a soft plastic container having a structure capable of being folded and housed inside, the arc-shaped ridges are provided on the side that should be the inner layer along the parting line and in a convex shape toward the outside. , The distance (X) between the center line of the ridge and the parting line is short at the point where the wall thickness (t) of the molded product is thin,
It is characterized in that it is long at the thick point, and the height (Y) of the ridge is low at the thin point of the molded product and high at the thick point.

In the soft plastic container having such a foldable accommodating structure, (a) when the folding inner layer is inverted and accommodated in the folding outer box, depending on the part, 90 ° (C part) to 180 ° (A, B part) It is necessary to fold it at a different angle than) and at a steep angle. (B) Since this bent portion is bent along a parting line having a substantially rectangular shape, there is a significant partial difference in the degree of elongation of the material of the bent portion (internal strain of the material), especially in the vicinity of the corners.

(C) There is an unavoidable non-uniformity of the thickness (t) [for example, A, B, C parts in FIG. 2 (a)] associated with the molding method by vacuum or blow molding in manufacturing the container.

The present invention relates to a structure of a container for clearing such a complicated factor and smoothly, neatly, and without folding point so that the folding portion is not easily scratched. The purpose was achieved by setting the relationship between t and X, Y under the predetermined conditions as described above.

This depends on the means found as a result of various trial experiments, but the reason for the effect of adopting such means can be interpreted as a composite of several effects described below.

First, in a portion where the wall thickness (t) is large (for example, portion A), the arc-shaped groove in the mold is deep, that is, since the protrusion is high (Y size), the arc bulges and becomes large and the wall thickness becomes thin. On the contrary, a portion having a small wall thickness (t) (for example, a C portion) has a small ridge, so that the arc is small and the wall thickness is small. As a result, in the vicinity of the tip of the ridge, which is the center of bending, the unevenness tends to be averaged regardless of the peripheral thickness (t) unevenness, and smooth folding is possible.

Another interpretation is that in the case of such a bag manufacturing method, partial thickness unevenness of the bag is unavoidable, but in the case of the configuration of the present invention, when the inner thickness t is large, the rigidity of the material is Since the bending portion is relatively large, the curvature of the bent portion is large (small bending does not occur). Therefore, the ridge should be separated from the parting line (X is large) and a high ridge (Y is large) should be provided in advance. On the contrary, when t is small, X and Y are made small, and X and Y are gradually changed continuously according to the change of the thickness t, for example, the change of the thickness of each part of A (thickness) → B → C (thin). Therefore, it is considered that the above-mentioned object was achieved because abrupt discontinuous change in bending rigidity or curvature is prevented and a protrusion point is less likely to occur.

However, if the ridges are too high (Y is too large) or too far from the parting line (X is too large), when the folds are made or when the inside is filled with liquid, the ridges themselves may become outside boxes or other It will come into direct contact with the container. [Fig. 4 (a ')
Comparative Example] It has been found as a result of a trial experiment that the numerical values shown in the examples of the present application are most suitable. Therefore, when the structure shown in Table 1 is used, the position of the ridge, which is the center of bending, is regulated by X to prevent rubbing, and the height Y of the ridge is regulated so that the thickness of the tip of the ridge is uniform. Therefore, the folding is smooth, and when folded and stored in a separate box, the tip of the parting line that protrudes most outwardly protrudes, and the area near the tip of the parting line mainly contacts the outer box, and the container itself, in particular, the convex ridge. It is difficult to get scratches in the vicinity, and it is possible to prevent the occurrence of protruding deformation,
In the conventional container of this type, it is possible to prevent the damage of the container from being damaged and the breakage of the container starting from the deformed portion, to improve the durability of the container, and to prevent the leakage accident.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a soft plastic container,
(A) shows the contents filled (actual liquid) state, (b) shows the folded state (empty liquid). FIG. 2 (a) is a perspective view of an embodiment of a container (inner bag before folding) according to the present invention. 2 (b), (c) and (d) are respectively shown in FIG. 2 (a).
It is an expanded sectional view of A zone, B zone, and C zone shown in FIG. FIG. 3 schematically shows a state in which the container is folded and stored in the outer box. FIG. 4 (a) shows a state (a ') (comparative example) in which, when X. or / and Y is too large, the tip of the ridge is hard to be protected by the parting line reinforcing reeve and is in contact with the inner surface of the outer box. It is a schematic representation. FIG. 5 (a) shows a swelled (actual liquid) state, and FIG. 5 (b) shows a schematic diagram (comparative example) showing a state in which a container which does not depend on the present application is folded and a projecting deformation (20) occurs. . Similarly, (c) and (d) of FIG.
A sectional view taken along the line O-P is shown. (C) Y even if t is large
Is large and bulges, and the area near the tip of the ridge becomes thin,
In (a), since Y is small, the wall thickness in the vicinity of the tip of the ridge does not change much. (E) and (f) show a state in which they are folded, and it is schematically shown that both bent portions have an averaged wall thickness. (E) and (f) show a state in which they are folded, and the thick (A) part has a large X and Y and is folded with a large curvature, while the thin (C) part is folded with a small curvature. It is shown that. In the figure 1 …… Inner bag (collective name including the folded outer layer and the inner layer) 2 …… Parting line 3 …… Projection line 5 …… Projection center line 6 …… Parting line center line 11 …… Folding outer layer 12 …… Folding inner layer 13 …… Plug 20 …… Deformed fold (sometimes referred to as a protruding point) 21 …… Outer box (corrugated box, etc.) 22 …… Contact between outer box and fold 23… Inversion Sides of the part that is folded up and folded A, B, C …… Indicates the location (part) of each container X …… Spacing between 5 and 6 Y …… Height of ridge (3) t …… Thickness LM, OP ... Cross-section designation (point A and C of container)

Claims (1)

[Scope of utility model registration request] 1. Two isosceles triangular prism-shaped shells having an apex angle of substantially right angles, which are obtained by a molding method such as blow molding or vacuum molding,
A rectangular (or cubic) cube obtained by welding the periphery (the welding part is called a parting line) with the bottom surfaces facing each other and the joints of the both protruding toward the outside is one triangular prism. The part corresponding to the body (called the inner layer of the fold) is along the parting line, and the part corresponding to other triangular prisms (called the outer layer of the fold)
In a soft plastic container that has a structure that can be folded inside and folded to accommodate inside, it bulges in a circular arc shape along the parting line and toward the outside on the side that should be the folding inner layer. A ridge (hereinafter simply referred to as "ridge") is provided, and the distance between the center line of the ridge and the center line of the parting line is short at the thin point of the molded product and long at the thick point, and A foldable soft plastic container characterized in that the height of the strip is low at the thin point of the molded product and high at the thick point.