JP2002160719A - Foldable blow-molded bottle and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a foldable blow-molded bottle, whose fold line parts 8, 9 and 10 for folding side plates 4 and 5 of a bottle body part 3 are formed in the desired positions of the side plates 4 and 5, and which makes the fold line parts 8, 9 and 10 have structures such that the side plates 4 and 5 can be easily folded even if the bottle is molded from a relatively rigid resin material such as high density polyethylene(HDPE), polypropylene(PP) or polyethylene telephthalate(PET) so as to have high rigidity. SOLUTION: The fold line parts 8, 9 and 10 are composed of thin parts 11 and 15 extended in an extent-of-line direction. The thin parts 11 and 15 are installed consecutively in a thick part 12 constituting the side plates 4 and 5, and thickness of each of the thin parts 11 and 15 is taken as not more than half that of the thick part 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a blow-molded bottle that can be folded at the time of disposal after use, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A conventional foldable synthetic resin bottle container is disclosed in, for example, Japanese Patent Application Laid-Open No. 10-31614.
No. 0, Japanese Utility Model 2604604, Japanese Utility Model 2000-
Japanese Patent Publication No. 38 discloses an example. In these conventional techniques, a relatively flexible mixture of 100 to 50% by weight of low-density polyethylene and 0 to 50% by weight of high-density polyethylene is used as a bottle molding material so that folding can be easily performed. Using a mixed resin material. And
The side plate is provided with ribs protruding in a semi-arc shape on the inner surface side or the outer surface side, so that the bottle can be folded.

[0003]

However, there are many bottles made of relatively hard resin materials such as high-density polyethylene and PET on the market. In the case of such a hard resin bottle, even if the above-described rib is provided, it is difficult to bend at this portion because the thickness of the rib formed by blow molding is relatively large.

[0004] The present invention relates to a relatively hard mixture of high-density polyethylene or polyethylene terephthalate or about 10 parts by weight of low-density polyethylene mixed with 100 parts by weight of high-density polyethylene to improve impact resistance. It is an object of the present invention to easily fold a bottle formed from a resin material or the like at the time of disposal or the like.

[0005]

In order to achieve the above object, the present invention takes the following technical measures.

That is, the foldable blow-molded bottle of the present invention has a fold line portion for bending the side plate at a desired position of the side plate of the bottle body. By folding the side plate along the fold line,
Bottles can be compactly folded and discarded. The basic structure of the bottle can be various, such as a mouth,
It may have a shoulder and a trunk, and may be formed by direct blow molding, may be formed by injection blow molding, and may further be stretch blown. The molding resin may be stretched and oriented by molding. The bottle body may be, for example, a rectangular tube, a hexagonal tube, an octagonal tube, or the like. The bottle body can include a plurality of side plates connected in the circumferential direction so as to have a cylindrical shape, and a bottom plate. When 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-shaped bottom plate. The folding 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 formed with fold line portions extending in the upper and lower portions, respectively, and the left and right side plates are formed at a height corresponding to the fold line portions. Forming a fold line portion extending in the vertical 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 the vertical direction at a height corresponding to the horizontal fold line portions in the upper and lower portions The upper and lower ends of the fold line portion may be diagonally branched to the front and rear sides. In this case, it is preferable that the left and right side plates are configured to be narrower than the front and rear side plates. Further, the fold line portion can be formed into a mountain fold line portion for mountain fold and a valley fold line portion for valley fold depending on the position where the fold line is provided. For example,
In the case of the above-mentioned rectangular body, the horizontal 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 Part. Also, the lateral fold line portions of the front and rear plates may be valley fold line portions, the lateral fold line portions of the left and right side plates may be valley fold line portions, and the vertical fold line portions of the left and right side plates may be mountain fold line portions. . In addition, a thin fold line portion extending in the vertical direction may be provided at a corner portion between the side plates, so that the corner portion can be easily bent.

[0007] The folding line portion can be constituted by a thin portion extending in the line length direction. The thin portion can be provided continuously with the thick portion constituting the side plate. In this way, by forming the fold line portion with the thin portion, even if the bottle is blow-molded from a relatively hard resin material, the bottle can be folded by easily folding the side plate at the time of disposal or the like. Here, the thickness of the thin portion is preferably not more than half the thickness of the thick portion. Specifically, the minimum thickness of the thin portion constituting the folding line portion is 0.5 mm
Below, more preferably 0.3 mm or less, it is good to blow-molding so that the average thickness of the thick portion constituting the side plate is 0.6 mm or more, more preferably 0.7 mm or more. In addition, it is possible to easily fold the bottle by disposing the side plate at the time of disposal, etc., while securing the rigidity of the bottle by the relatively thick side plate.

In the above-mentioned bottle of the present invention, the outer surface of the thin portion constituting the folding line portion may be substantially flush with the outer surface of the body side plate. According to this, the outer surface of the bottle becomes flat, and the external appearance productability is improved.

Further, the blow molded bottle of the present invention can be foldable in which 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 portion extending in the line length direction, whereby even a bottle obtained by blow-molding a relatively hard resin material can easily bend the side plate to form a bottle. Can be folded. Also,
A pair of bending restricting portions may be provided on both sides in the line width direction of at least one of the thin portions of the folding line portion so as to restrict the folding of the folding line portion in the opposite direction. The bending restricting portion can be configured to be thicker and thicker than the thinner portion, and preferably can be configured to be twice or more the thickness than the thinner portion. By providing the bending direction regulating portion in this manner, each folding line portion is inevitably bent in an appropriate direction, and the folding workability of the bottle is improved. The bending direction restricting portions may be provided on all the folding line portions provided on the side plate, or may be provided only partially, for example, only on the valley folding line portions.

In the bottle of the present invention, each bending direction regulating portion is formed to be curved so as to project inward from the outside in the line width direction toward the inside in the line width direction.
The inner edge is extended toward the outside of the bottle, and the thin portion can be integrally provided between the inner edges of the pair of bending restricting portions. A valley fold line portion whose mountain folding is restricted by the pair of bending restriction portions is obtained.

Further, the outer surface of the thin portion of each fold line portion is formed to be substantially flush with the outer surface of the side plate of the bottle body, thereby improving the appearance and product quality.

Incidentally, the cross-sectional structure in the vicinity of the mountain fold line portion can be an appropriate one. For example, a thin portion is integrally provided between the inner edges of a pair of thick curved portions extending in the line length direction, and by increasing the line width of the thin portion, the pair of curved portions abut each other. Even so, it is possible to provide a structure in which the thin portion extends in the line width direction and can be easily mountain-folded. In this case, by forming the thin portion into a corrugated plate or the like, the thin portion easily extends in the line width direction at the time of mountain folding while securing rigidity before folding, and the mountain folding line portion is mountain-folded. Can be. The curved portion of the mountain fold line portion is curved inward of the bottle due to a mold structure for forming a thin portion.

The present invention also proposes a foldable blower in which a fold line is formed at a desired position on a side plate of a bottle body by blowing a cylindrical preform in a blow mold. This is a method for producing a molded bottle. In the manufacturing method of the present invention, a pair of ribs is provided at a predetermined interval on the surface of the mold surface of the blow molding die where the mountain fold line portion and the valley fold line portion are to be formed,
By making the stretching ratio between the ribs relatively large, the thin folded line portion can be formed between the ribs.
According to this, while simplifying the structure of the preform before blow molding and facilitating attachment of the preform to the blow molding die, the resin material is greatly stretched between the pair of ribs to achieve a thin wall. By adjusting the distance between the pair of ribs, it is also possible to form the bending-regulating thick portion of the valley fold line portion. In order to form the thin portion of the mountain fold line portion into a corrugated plate shape, the mold surface between the pair of ribs may be formed in a corrugated shape in the line width direction.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a blow-molded bottle 1 according to one embodiment of the present invention. The bottle 1 has a cylindrical mouth portion 2 and a substantially rectangular parallelepiped bottomed hollow body portion 3. It has. The body 3 includes front and rear side plate parts 4 having a relatively wide width, left and right side plate parts 5 which are relatively narrower than the front and rear side plate parts 4, a bottom plate part, and a shoulder plate part 7. In addition, a thread may be formed on the outer periphery of the mouth 2, and a cap, a pump, or the like can be attached to the mouth 2. As a molding material of the bottle 1, a relatively rigid high-density polyethylene, polypropylene, PET, or the like can be used, and a material obtained by appropriately mixing additives and the like can also be used. In order to improve impact resistance, a mixed resin material in which low-density polyethylene is mixed with high-density polyethylene in such an amount that rigidity is not excessively reduced may be used.

The front and rear side plate portions 4 are each formed with a valley fold line portion 8 which extends laterally 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 laterally from both ends in the width direction toward the center at a height corresponding to the valley fold line portion 8 and a substantially central portion in the width direction of the left and right side plate 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 ends are diagonally branched to both front and rear sides at a height corresponding to the upper and lower lateral valley fold line portions 8.

Each of the side plates 4 and 5 has a thickness of 0.8 mm to 1.0 mm.
2 (a), the valley fold lines 8, 10 are formed by thin portions 11 extending in the line length direction, as shown in FIG. 2 (a). . 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 a thick portion 12 which mainly constitutes the side plates 4 and 5, and the outer surface of the thin portion 11 is
2 are formed substantially flush with the outer surfaces of the side plates 4 and 5 formed by the second plate 2.

On both sides in the line width direction of the thin portions 11 of the valley fold lines 8, 10, a pair of bending restricting portions 13 are provided which come into contact with each other in order to restrict the mountain folds of the fold lines 8, 10. I have.
The bending restricting portion 13 is formed in a long shape over the entire length of the valley fold line portions 8 and 10 in the line length direction, and the thin portion 1
It is formed in a thick shape having a thickness of 1 or more, preferably about 1.0 mm. Each of the bending restricting portions 13 is formed so as to protrude toward the inside of the bottle 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. In addition, the thin portion 11 is provided integrally between the inner edges of the pair of bending restricting portions 13. Before folding the bottle, a slight gap is provided between the pair of bending restricting portions 13 as shown in FIG. Further, by forming the bending restricting portion 13 in the above-described structure, concave grooves 14 extending in the line length direction are formed on both sides of the thin portion 11 in the line width direction. When the valley fold lines 8 and 10 are to be mountain-folded, the mountain-folding is restricted by the contact between the pair of bending restricting portions 13 as shown in FIG. 2B. On the other hand, the valley fold can be performed with little resistance because the thin portion 11 is easily deformed as shown in FIG. When the valley is folded, the thin portion 1
The thick portions 12 on both sides of 1 are brought close to each other.

As shown in FIG. 3A, the mountain fold line portion 9 is constituted by a thin portion 15 extending in the line length direction. The thickness of the thin portion 15 is 0.1 mm
~ 0.5mm, more preferably 0.2mm ~ 0.4mm
It can be. The thin portion 15 is connected to the thick portion 12 that mainly forms 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 formed by the thick portion 12. I have.

A pair of curved portions 16 are provided on both sides in the line width direction of the thin portion 15 of the mountain fold line portion 9. 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 of at least twice the thin portion 15 and preferably about 1.0 mm. Have been. Each curved portion 16 is formed so as to protrude inward from the bottle in the line width direction inward from the line width direction outward, and extends toward the outside of the bottle at an inner edge thereof. The thin portion 15 is provided integrally between the inner edges of the pair of curved portions 16. The pair of curved portions 1
Before the bottle is folded, a relatively large space is provided between them as shown in FIG. Further, by forming the curved portion 16 in 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 portion 15 is formed in a wavy cross section so as to be extendable in the line width direction. In the illustrated example, a wavy cross section is obtained by bending the center of the thin portion 15 inward of the bottle. ing.

When this mountain fold line portion 9 is mountain-folded, FIG.
As shown in (b), the side plate 5 is bent at the folding line portion 9 in the mountain folding direction in a state where the thin portion 15 extends in the line width direction and the pair of curved portions 16 are close to or in contact with each other. In the folded state, the thick portions 12, 1 on both sides of the thin portion 15 are formed.
2 are separated from each other by a curved portion 16 minutes, and the thick portions 1 on both sides are separated.
A space is formed between 2 and 12.

In the bottle 1 of the present embodiment, the body 3
The corners between the front and rear side plates 4 and the left and right side plates 5 of FIG.
(A) As shown in FIG.
And the thick portion 17 and the thin portion 18 provided between the side plates 4 and 5. Since the thin portion 18 is easily deformed, it is folded as shown in FIG. Alternatively, the side plates 4 and 5 can be expanded so as to be flush with each other.

The bottle can be manufactured, for example, by blow-molding an injection-molded bottomed cylindrical preform P in a blow mold. A pair of ribs are protruded at predetermined intervals on the mold surface of the blow molding die at a position where the mountain fold line portion and the valley fold line portion are to be formed, and the stretch ratio between the ribs is compared. By making the target larger, each thin fold line portion can be formed between the pair of ribs. FIG. 5 illustrates, in an enlarged manner, a portion where the valley fold line portions 8 and 10 are formed. A pair of ribs 21 are provided on the blow molding die 20 at predetermined intervals to project inward. ing. The rib 21 is formed in a long shape over the entire length in the wire length direction. When the preform P is stretched radially outward,
First, as shown in FIG.
1 and is cooled and solidified from the contact portion. When the preform P is further extended, the resin material constituting the preform P enters between the pair of ribs 21 and the pair of ribs 2
A small amount of resin material between the two ribs 21 is stretched over the entire inner surface of the rib 21 to increase the elongation ratio, and the rib 21
The bottom portion between them is formed to be thin. Similar ribs are provided on the die surface of the mold also at the portion forming the mountain fold line portion, and the interval between the pair of ribs for forming the mountain fold line portion is relatively large. At the bottom between the pair of ribs,
An angled ridge for forming the thin portion 15 into a wave shape is provided.

The present invention is not limited to the above embodiment, and the design can be changed as appropriate. For example, by forming the vertical fold curve 10 provided on the left and right side plates 5 as a mountain fold line portion and the horizontal fold curve 9 as a valley fold line portion, the bottle 1 can be expanded so that the left and right side plates 5 are pushed out of the bottle. It can also be folded.

[0025]

According to the present invention, even when a bottle is formed using a resin material having relatively high rigidity, the bottle is compactly folded by easily bending the side plate of the bottle body at the time of disposal or the like. By limiting the bending direction, even if the molding material has a certain degree of rigidity, it can be folded. Therefore, PET bottles and PP bottles can be folded and discarded,
It is also possible to reduce the collection cost and the like of these bottles having a large production volume and a large distribution volume.

[Brief description of the drawings]

FIG. 1 is a simplified perspective view of a blow-molded bottle according to one embodiment of the present invention.

FIGS. 2A and 2B show an embodiment of a valley fold line portion on which a mountain fold regulating thick portion is formed. FIG. 2A is an enlarged cross-sectional view in the line width direction before bending, and FIG. FIG. 3C is an enlarged cross-sectional view when the valley is folded.

3A and 3B show an embodiment of a mountain fold line portion, wherein FIG. 3A is an enlarged cross-sectional view in the line width direction before bending, and FIG.

FIG. 4 shows an embodiment of a corner portion of a bottle body,
(A) is an enlarged sectional view before folding, and (b) is an enlarged sectional view after folding.

FIG. 5 is an enlarged cross-sectional view of a blow molding die at a portion where a valley fold line portion of the bottle is formed according to the embodiment, wherein (a) is an explanatory view of a preform stretching process, and (b) is blow-completed. FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 blow molded bottle 2 mouth 3 trunk 4 front and rear side plate 5 left and right side plate 8, 10 valley fold line portion 9 mountain fold line portion 11, 15 thin portion 12 thick portion 13 bending restricting portion 20 blow molding die 21 rib

Claims (6)

[Claims] 1. A fold in which fold lines (8, 9, 10) for bending the side plates (4, 5) are formed at desired positions on the side plates (4, 5) of the bottle body (3). A possible blow-molded bottle, wherein the fold lines (8, 9, 10)
Is constituted by thin portions (11, 15) extending in the line length direction, and the thin portions (11, 15) are connected to the thick portions (12) constituting the side plates (4, 5). The foldable blow-molded bottle, wherein the thickness of the thin portions (11, 15) is not more than half of the thickness of the thick portions (12). 2. An outer surface of a thin portion (11, 15) constituting a fold line portion (8, 9, 10) is substantially flush with an outer surface of a body side plate (4, 5). A foldable blow molded bottle according to claim 1. 3. A fold line portion (9) and a valley fold line portion (8, 10) at desired positions on the side plates (4, 5) of the bottle body (3).
And a foldable blow-molded bottle formed with fold lines, wherein each fold line portion (8, 9, 10) is constituted by a thin portion (11, 15) extending in the line length direction. At least one of the thin portions (11) of the portions (8, 9, 10) has a pair of abutting portions on both sides in the line width direction to restrict the folding of the folding line portions (8, 10) in the opposite direction. A foldable blow-molded bottle characterized by being provided with a fold restricting portion (13). 4. Each of the bending restricting portions (13) is curved so as to protrude inward from the outside in the line width direction toward the inside in the line width direction. 4. The fold according to claim 3, wherein the thin portion (11) is integrally provided between the inner edges of the pair of bending control portions (13). Possible blow molded bottles. 5. An outer surface of a thin portion (11, 15) of each fold line portion (8, 9, 10) is substantially flush with an outer surface of a side plate (4, 5) of a bottle body (3). The foldable blow molded bottle according to claim 3 or 4, wherein the bottle is formed. 6. A cylindrical preform (P) is blow-molded in a blow mold (20) to form a fold line (8) at a desired position on a side plate (4, 5) of a bottle body (3). ,
9. A method for manufacturing a foldable blow-molded bottle on which a blow-molded bottle (9, 10) is formed, wherein the mountain fold line portion (9) and the valley fold line portion (8, 10) on the mold surface of the blow mold (20). A pair of ribs (21) is projected at a predetermined interval at a portion where the rib (21) is to be formed, and the stretching ratio between the ribs (21) is made relatively large so that a thin wall is formed between the ribs (21). A method for producing a foldable blow-molded bottle, characterized in that said folded line portions (8, 9, 10) are formed.