JP4588200B2 - Foldable blow molded bottle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a blow molded bottle that can be folded at the time of disposal after use, and a method for manufacturing the same.
[0002]
[Prior art]
Examples of such conventional foldable synthetic resin bottle containers include those described in JP-A No. 10-316140, No. 2604604, and No. 2000-38. In these conventional technologies, as a bottle molding material, 100 to 50% by weight of low density polyethylene and 0 to 50% by weight of high density polyethylene are mixed so as to be easily folded. The mixed resin material is used. And the bottle can be folded by providing the rib which protruded in the semicircular arc shape in the inner surface side or the outer surface side in the side plate.
[0003]
[Problems to be solved by the invention]
However, there are many bottles made of a relatively hard resin material such as high-density polyethylene or PET in the market. In the case of such a hard resin bottle, even if the rib as described above is provided, it is difficult to bend at this portion because the rib formed by blow molding is relatively thick.
[0004]
The present invention is a high-density polyethylene, polyethylene terephthalate, or a relatively hard mixed resin material in which about 10 parts by weight of low-density polyethylene is mixed with 100 parts by weight of high-density polyethylene to improve impact resistance. It is an object of the present invention to make it possible to easily fold a bottle formed from the above when discarded.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the present invention takes the following technical means.
[0006]
That is, the foldable blow-molded bottle of the present invention has a fold line portion for folding the side plate at a desired position of the side plate of the bottle body. The bottle can be discarded by folding the bottle compactly by folding the side plate along the fold line portion. In addition, the basic structure of the bottle can be various, and can be provided with a mouth, a shoulder, and a trunk, and can be molded by a direct blow molding method, The molded resin may be molded by an injection blow molding method, and further, a molded resin may be stretched and oriented by stretch blow molding. The bottle body portion may be, for example, a rectangular cylinder, a hexagonal cylinder, an octagonal cylinder, or the like. The bottle body portion may include a plurality of side plates that are continuously provided in the circumferential direction so as to have a cylindrical shape, and a bottom plate. In the case where the bottle body is a rectangular cylinder, the body can include front and rear side plates, left and right side plates, and a square plate-like bottom plate. The fold line portion is provided at a desired position in the plate surface of the side plate. For example, in the case of a rectangular cylindrical bottle body, the front and rear side plates are respectively formed with fold line portions extending in the lateral direction at the upper and lower portions thereof, and the left and right side plates are laterally arranged at a height corresponding to the fold line portions. Forming a fold line portion extending in the direction and a fold line portion extending in the vertical direction at a substantially central position in the width direction of the left and right side plates, and in the vertical direction at a height corresponding to the upper and lower horizontal fold line portions. The upper and lower end portions of the fold line portion may be branched obliquely to both the front and rear sides. In this case, it is preferable that the left and right side plates are narrower than the front and rear side plates. Further, the fold line portion can be divided into a mountain fold line portion for mountain fold and a valley fold line portion for valley fold depending on the position of the fold line portion. For example, in the case of the rectangular body, the lateral fold line portion of the front and rear side plates is a valley fold line portion, the horizontal fold line portion of the left and right side plates is a mountain fold line portion, and the vertical fold line portion of the left and right side plates is a valley fold line portion. It can be a fold line portion. Also, the lateral fold line portion of the front and rear side plates can be a valley fold line portion, the horizontal fold line portion of the left and right side plates can be a valley fold line portion, and the vertical fold line portion of the left and right side plates can be a mountain fold line portion. . Note that a thin fold line portion extending in the vertical direction may also be provided at the corner portion between the side plates, whereby the corner portion can be easily folded.
[0007]
The fold line portion can be constituted by a thin wall portion extending in the line length direction. This thin part can be connected to the thick part constituting the side plate. In this way, by configuring the folding line portion with a thin portion, even when the bottle is blow-molded from a relatively hard resin material, the bottle can be folded easily by folding the side plate at the time of disposal or the like. Here, it is preferable that the thickness of the thin portion is not more than half of the thickness of the thick portion. Specifically, the minimum thickness of the thin part constituting the fold line part is 0.5 mm or less, more preferably 0.3 mm or less, and the average thickness of the thick part constituting the side plate is 0.6 mm or more, more Preferably, blow molding is performed so that the thickness is 0.7 mm or more, and according to this, the side plate is easily folded at the time of disposal or the like while securing rigidity as a bottle with a relatively thick side plate. Can be folded.
[0008]
In the bottle of the present invention, the outer surface of the thin portion constituting the fold line portion may be substantially flush with the outer surface of the trunk side plate. According to this, the outer surface of the bottle becomes flat, and the appearance merchandise becomes good.
[0009]
In addition, the blow molded bottle of the present invention can be folded such that a mountain fold line portion and a valley fold line portion are formed at desired positions on the side plate of the bottle body. Each fold line portion can be constituted by a thin-walled portion extending in the line length direction, so that even if the bottle is obtained by blow molding a relatively hard resin material, the side plate can be easily folded and the bottle Can be folded. In addition, a pair of bending restricting portions that are in contact with each other so as to restrict folding in the opposite direction of the fold line portion can be provided on both sides in the line width direction of at least one of the fold line portions. The bending restricting portion can be configured to be thicker than the thin portion, and preferably can be configured to be twice or more thicker than the thin portion. By providing the folding direction restricting portion in this way, each folding line portion inevitably bends in an accurate direction, and the bottle folding workability is improved. The bending direction restricting portion may be provided in all fold line portions provided on the side plate, or may be provided only in a part, for example, a valley fold line portion.
[0010]
In the bottle of the present invention, each bending direction restricting portion is curved so as to protrude inward from the outer side in the line width direction toward the inner side in the line width direction, and outward from the bottle at its inner edge. The thin-walled portion may be integrally provided between the inner edges of the pair of bending restricting portions. A valley fold line part regulated by the folding regulation part is obtained.
[0011]
Further, the outer appearance of the thin wall portion of each folding line portion is formed so as to be substantially flush with the outer surface of the side plate of the bottle body portion, thereby improving the appearance merchandise.
[0012]
Note that the cross-sectional structure in the vicinity of the mountain fold line portion can be set appropriately. For example, a structure in which a thin portion is integrally provided between the inner edges of a pair of curved portions extending in the direction of the thick line length, and the pair of curved portions abut on each other by increasing the line width of the thin portion. Even in this case, the thin-walled portion can extend in the line width direction and can be easily foldable. In this case, the thin wall portion is corrugated to ensure rigidity before folding, and the thin wall portion easily extends in the line width direction at the time of mountain folding, so that the mountain folding line portion is folded into a mountain. Can do. The curved portion of the mountain fold line portion is curved inward of the bottle due to the mold structure for forming the thin portion.
[0013]
In addition, the present invention proposed at the same time provides a foldable blow-molded bottle in which a fold line portion is formed at a desired position on the side plate of the bottle body by blow-molding a cylindrical preform in a blow mold. It is a manufacturing method. In the manufacturing method of the present invention, a pair of ribs are protruded from the mold surface of the blow mold at a position where the mountain fold line portion and the valley fold line portion should be formed, with a predetermined interval, By making the stretch ratio between the ribs relatively large, the thin fold line portion can be formed between the ribs. According to this, while simplifying the structure of the preform before blow molding and facilitating the mounting of the preform on the blow mold, the resin material is greatly stretched between the pair of ribs to reduce the thickness. In addition, by adjusting the distance between the pair of ribs, it is also possible to form a thick portion for bending regulation of the valley fold line portion. In addition, in order to form the thin part of the said mountain fold line part in corrugated form, the type | mold surface between a pair of ribs can be formed in the waveform in the line width direction.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
[0015]
FIG. 1 shows a blow molded bottle 1 according to an embodiment of the present invention, and the bottle 1 includes a cylindrical mouth portion 2 and a hollow body portion 3 having a substantially rectangular parallelepiped shape and a bottom. Yes. The body portion 3 includes a front and rear side plate portion 4 having a relatively wide width, a left and right side plate portion 5 that is relatively narrower than the front and rear side plate portion 4, a bottom plate portion, and a shoulder plate portion 7. In addition, you may form a screw thread in the outer periphery of the opening part 2, and a cap, a pump, etc. can be attached to this opening part 2. FIG. As the molding material of the bottle 1, relatively rigid high-density polyethylene, polypropylene, PET, or the like can be used, and a material obtained by appropriately mixing an additive or the like can also be used. Moreover, in order to improve impact resistance, a mixed resin material obtained by mixing low-density polyethylene in an amount such that rigidity does not decrease excessively with high-density polyethylene can be used.
[0016]
The front and rear side plate portion 4 is formed with valley fold line portions 8 extending in the lateral direction at the upper and lower portions thereof. On the other hand, the left and right side plate portions 5 include a mountain fold line portion 9 extending in the lateral direction from both ends in the width direction at a height corresponding to the valley fold line portion 8 and a substantially center in the width direction of the left and right side plates 5. A valley fold line portion 10 extending in the vertical direction at the position is formed. The valley fold line portion 10 is formed such that the upper and lower end portions are obliquely branched to the front and rear sides at a height corresponding to the upper and lower lateral valley fold line portions 8.
[0017]
Each of the side plates 4 and 5 is mainly configured in a thick plate shape having a thickness of about 0.8 mm to 1.0 mm, while the valley fold line portions 8 and 10 are formed as shown in FIG. The thin portion 11 extends in the line length direction. The thickness of the thin portion 11 can be 0.1 mm to 0.5 mm, more preferably 0.2 mm to 0.4 mm. The thin portion 11 is connected to the thick portion 12 that mainly constitutes the side plates 4 and 5, and the outer surface of the thin portion 11 is substantially flush with the outer surface of the side plates 4 and 5 constituted by the thick portion 12. Is formed.
[0018]
On both sides in the line width direction of the thin wall portion 11 of the valley fold line portions 8 and 10, a pair of fold regulation portions 13 that abut against the fold line portions 8 and 10 to regulate mountain folds is provided. The bending restricting portion 13 is formed in a long shape extending over the entire length in the line length direction of each of the valley fold line portions 8 and 10, and has a thickness that is at least twice that of the thin portion 11, preferably about 1.0 mm. It is formed in a meat shape. Each bend restricting portion 13 is curved so as to project inward from the outer side in the line width direction toward the inner side in the line width direction, and is extended toward the outer side of the bottle at the inner edge thereof. The thin portion 11 is integrally provided between the inner edges of the pair of bending restricting portions 13. A slight gap is provided between the pair of bending restricting portions 13 before the bottle is folded as shown in FIG. Moreover, the groove | channel 14 which extends in a line length direction is formed in the line | wire width direction both sides of the thin part 11 by making the bending control part 13 into said structure. When attempting to fold such valley fold line portions 8 and 10, mountain folds are regulated by the pair of folding regulating portions 13 coming into contact with each other as shown in FIG. On the other hand, the valley folding can be performed with almost no resistance because the thin portion 11 is easily deformed as shown in FIG. In the state where the valley is folded, the thick portions 12, 12 on both sides of the thin portion 11 come close to each other.
[0019]
Further, the mountain fold line portion 9 is constituted by a thin portion 15 extending in the line length direction, as shown in FIG. The thickness of the thin portion 15 can be 0.1 mm to 0.5 mm, more preferably 0.2 mm to 0.4 mm. The thin portion 15 is connected to the thick portion 12 that mainly constitutes the side plate 5, and the outer surface of the thin portion 15 is formed substantially flush with the outer surface of the side plate 5 constituted by the thick portion 12. Yes.
[0020]
A pair of curved portions 16 are provided on both sides of the thin portion 15 of the mountain fold line portion 9 in the line width direction. The curved portion 16 is formed in a long shape extending over the entire length of each mountain fold line portion 9 in the line length direction, and is formed in a thick shape having a thickness that is at least twice that of the thin portion 15, preferably about 1.0 mm. Has been. Each curved portion 16 is curved and formed so as to protrude inward from the outside in the line width direction toward the inside in the line width direction, and extends toward the outside of the bottle at the inner edge thereof. The thin portion 15 is integrally provided between the inner edges of the pair of curved portions 16. A relatively large space is provided between the pair of curved portions 16 as shown in FIG. 3A before the bottle is folded. Further, by forming the curved portion 16 with the above-described structure, concave grooves 17 extending in the line length direction are formed on both sides of the thin portion 15 in the line width direction. Further, the thin wall portion 15 is formed in a corrugated shape so as to be extensible in the line width direction. In the illustrated example, a corrugated cross section is obtained by curving the center of the thin wall portion 15 inward of the bottle. ing.
[0021]
When the mountain fold line portion 9 is folded, the thin wall portion 15 extends in the line width direction as shown in FIG. 3B, and the side plate 5 is folded in a state where the pair of curved portions 16 are close to or in contact with each other. The wire 9 is bent in the mountain fold direction. Note that, in the state of being folded in a mountain, the thick portions 12, 12 on both sides of the thin portion 15 are separated from each other by the curved portion 16, and a space is formed between the thick portions 12, 12 on both sides.
[0022]
Further, in the bottle 1 of the present embodiment, the corner portion between the front and rear side plates 4 and the left and right side plates 5 of the trunk portion 3 is formed with a thick portion 17 that curves inward of the bottle as shown in FIG. It is composed of a thick portion 17 and a thin portion 18 provided between the side plates 4 and 5, and since the thin portion 18 is easily deformed, it can be folded as shown in FIG. The adjacent side plates 4 and 5 can be expanded so as to be flush with each other.
[0023]
The bottle can be produced, for example, by blow molding a bottomed cylindrical preform P that has been injection molded in a blow mold. A pair of ribs are protruded with a predetermined interval on the portion of the mold surface of the blow mold to form the mountain fold line portion and the valley fold line portion, and the stretch ratio between the ribs is compared. By making the size larger, it is possible to form thin fold line portions between the pair of ribs. FIG. 5 shows an enlarged view of the portion where the valley fold line portions 8 and 10 are formed. A pair of ribs 21 project inward from the blow mold 20 with a predetermined interval. ing. The rib 21 is formed in an elongated shape over the entire length in the line length direction. When the preform P is extended outward in the radial direction, first, as shown in FIG. 5A, the preform P comes into contact with the tip of the rib 21 and is cooled and solidified from the corresponding contact portion. When further stretched, the resin material constituting the preform P enters between the pair of ribs 21 and a small amount of resin material between the pair of ribs 21 is stretched over the entire inner surface of the rib 21. The stretching ratio increases, and the bottom between the pair of ribs 21 is formed thin. Note that similar ribs are also provided on the mold surface in the portion constituting the mountain fold line portion, and the distance between the pair of ribs for forming this mountain fold line portion is relatively large. In the bottom between the pair of ribs, a chevron is provided for forming the thin portion 15 into a wave shape.
[0024]
The present invention is not limited to the above-described embodiment, and the design can be changed as appropriate. For example, the vertical folding line 10 provided on the left and right side plates 5 is a mountain fold line part, and the horizontal folding line 9 is a valley fold line part, so that the left and right side plates 5 are pushed outward from the bottle. It can also be folded.
[0025]
【The invention's effect】
According to the present invention, even a bottle formed using a resin material having a relatively large rigidity can be easily folded at the time of disposal or the like so that the bottle can be folded compactly. By limiting the folding direction, the molding material can be folded even if the molding material has a certain degree of rigidity. Therefore, it is possible to fold and discard PET bottles and PP bottles, and it is possible to reduce the recovery cost of these bottles with a large production volume and distribution volume.
[Brief description of the drawings]
FIG. 1 is a simplified perspective view of a blow molded bottle according to an embodiment of the present invention.
FIGS. 2A and 2B show an example of a valley fold line portion in which a thick portion for mountain fold regulation is formed. FIG. 2A is an enlarged sectional view in a line width direction before bending, and FIG. (C) is an enlarged sectional view when the valley is folded.
FIGS. 3A and 3B show an embodiment of a mountain fold line portion, where FIG. 3A is an enlarged sectional view in a line width direction before folding, and FIG. 3B is an enlarged sectional view when the mountain is folded;
4A and 4B show an embodiment of a corner portion of a bottle body, in which FIG. 4A is an enlarged sectional view before folding, and FIG. 4B is an enlarged sectional view after folding.
FIGS. 5A and 5B are enlarged sectional views of a blow molding die at a portion where a valley fold line portion of the bottle according to the embodiment is formed, in which FIG. 5A is an explanatory view of a preform stretching process, and FIG. 5B is a blow completed. It is explanatory drawing at the time.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Blow molding bottle 2 Mouth part 3 Body part 4 Front and rear side plate 5 Left right side plate 8, 10 Valley fold line part 9 Mountain fold line part 11, 15 Thin part 12 Thick part 13 Bending part 20 Blow molding die 21 Rib

Claims (3)

A foldable blow-molded bottle in which a mountain fold line part (9) and a valley fold line part (8, 10) are formed at desired positions on the side plates (4, 5) of the bottle body part (3), Each fold line portion (8, 9, 10) is constituted by a thin portion (11, 15) extending in the line length direction, and at least one of the fold line portions (8, 9, 10) is A pair of bending restricting portions (13) are provided on both sides of the thin wall portion (11) in the line width direction, and are opposite to the folding line portions (8, 10) provided with the bending restricting portions (13). A foldable blow-molded bottle characterized in that a pair of folding restriction portions (13) abut against each other in order to restrict folding into a bottle.   Each bending restricting portion (13) is curved so as to project inward from the outside in the line width direction toward the inside in the line width direction, and extends toward the outside of the bottle at its inner edge. The foldable blow-molded bottle according to claim 1, wherein the thin-walled portion (11) is integrally provided between the inner edges of the pair of folding restriction portions (13). .   The outer surface of the thin part (11, 15) of each fold line part (8, 9, 10) is formed to be substantially flush with the outer surface of the side plate (4, 5) of the bottle body (3). The foldable blow molded bottle according to claim 1 or 2.

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