JPH08310521A - Synthetic resin bottle - Google Patents

Abstract

PURPOSE: To obtain a bottle whose pressure-reduction-absorbing ability is high without decreasing its buckling strength, by allowing the entire flat wall provided with a panel wall to be depressed and deformed easily in an even, stable form. CONSTITUTION: A flat wall 4 having a panel wall 5 is formed in the body 2, peripheral grooves 3 are provided above and below the flat wall 4, and in an area stretching from the flat wall 4 into the peripheral groove 3 a recessed part 6 is provided. Ridge lines 7 formed at the edges of both ends of the grooved part 6 nullify the ability of the peripheral groove 3 to prevent depression and deformation of the flat wall 4, and at the same time depression and deformation of the flat wall 4 is indused by the ridge lines 7. Thus, the flat wall 4 is easily depressed and deformed in an even, stable form.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin bottle body, and more particularly to a body wall structure for a large bottle body which is biaxially stretch blow-molded with polyethylene terephthalate resin or the like.

[0002]

2. Description of the Related Art A synthetic resin bottle, especially a polyethylene terephthalate resin (hereinafter simply referred to as PET), etc. 2
The axially stretch blow-molded large bottle is economical because it can be molded relatively thinly due to the excellent properties of the molded synthetic resin material, and it is excellent in contents resistance and mechanical strength. Since it has a good appearance, it is used in various fields as a liquid container.

As described above, the biaxially stretch-blow molded synthetic resin bottle body has excellent mechanical strength despite its thinness, but the body portion, which is the main part of the bottle body, is thin. Therefore, there is an inconvenience that a part of the body is illegally depressed and deformed due to the reduced pressure generated in the bottle body, and the appearance of the bottle body as a product is remarkably deteriorated.

In order to eliminate the disadvantage of deformation under reduced pressure in the biaxially stretch blow molded synthetic resin bottle body, as disclosed in, for example, Japanese Utility Model Application Laid-Open No. 57-199511, it is depressed in the barrel wall of the body. By deforming multiple deformable panel walls that are easy to deform, the negative pressure generated in the bottle is absorbed by the uniform deforming deformation of this deformable panel wall, causing improper collapse deformation in other parts of the body. Various bottles have been proposed which are designed not to do this and to enhance the ability of the body to retain its own shape.

[0005]

However, in the above-mentioned prior art, the deformation of the deformed panel wall due to the reduced pressure absorption is surely caused in a constant form, and the deformed panel wall has the deformed deformation. In order to prevent the collapse deformation from affecting other parts of the body and causing improper deformation in the other parts of the body, a rib wall structure part that is hard to deform is provided around the deformed panel wall. In addition, it is necessary to provide a wall portion functioning as a pillar member between the deformed panel walls in order to prevent the buckling strength of the trunk portion from being reduced by providing the deformed panel wall. There is a problem in that the pressure cannot be sufficiently increased, and therefore the degree of reduced pressure that can be absorbed by the depressed deformation of the deformed panel wall is not sufficient.

In particular, in this type of bottle, in order to enhance the buckling strength of the body, a peripheral groove is depressed around the center of the body, and the peripheral groove of the deformed panel wall is formed by this peripheral groove. Since the height dimension cannot be set to a sufficient value, the area of the deformed panel wall never reaches a large value, and there is a problem that the deformed panel wall absorbs a reduced pressure.

Further, since the deformed panel wall is preliminarily formed in a slightly depressed inward shape so that the depressed deformation due to the decompression generated in the bottle easily occurs, the deformed panel wall of the deformed panel wall The degree of decompression that can be absorbed is small, so the degree of decompression that can be handled is low,
There is a problem that the applicable range is narrow.

Therefore, the present invention was devised to solve the above-mentioned problems in the prior art, and the flat wall portion provided with the deformed panel wall of the bottle body can be easily formed in a uniform and stable form. The present invention aims to provide a bottle body having a large decompression and absorption capability without lowering the buckling strength.

[0009]

Means for Solving the Problems The means of the present invention for solving the above-mentioned technical problem is to form a flat wall having a panel wall portion for absorbing reduced pressure on a barrel-shaped bottomed cylindrical body portion. The recessed circumferential groove is formed in the body in such a manner that it is connected to the upper and lower end edges of the flat wall. The recess is formed by a taper wall and a bottom wall that spread in one direction.

By making the concave portion laterally long, it is effective to position the left and right ridgelines formed between the tapered wall of the concave portion and the groove side walls of the circumferential groove near the side ends of the opposing flat walls. is there.

It is preferable that the body part has a bottomed parallel quadrangular tubular shape, and at least a pair of flat plate-shaped tube wall parts facing each other of the body part are flat walls.

It is practical to provide an upper circumferential groove in the center of the body in the height direction and a lower circumferential groove in the lower end of the body.

[0013]

The recess formed by the taper wall and the bottom wall that expands outward is naturally recessed in the portion from the center of the upper and lower ends of the flat wall to the groove bottom wall of the opposing circumferential groove. As a result, the depth of the recessed portion located in the flat wall portion, that is, the height of the tapered wall is larger than the depth of the recessed portion located in the peripheral groove portion, that is, the height of the tapered wall.

Therefore, both sides of the ridgeline formed between the flat wall and the taper wall of the concave portion located in the flat wall portion are formed on both sides of the ridge line of the concave portion located in the circumferential groove portion and the groove bottom of the circumferential groove. It will be positioned more laterally with respect to both side portions of the ridgeline formed between the ridgeline and the wall, so that the pair of ridgelines formed between the tapered wall of the recess and the groove side wall of the circumferential groove are The structure has a taper angle that spreads to the flat wall side.

As described above, on the groove side wall on the flat wall side of the peripheral groove which is the both end edges of the recess, a pair of ridge lines extending to the flat wall side,
That is, since a protruding bent portion is formed, when decompression occurs in the bottle body, in addition to the depression deformation of the deformation panel wall portion,
The ridgeline formed between the tapered wall of the recess and the circumferential groove is used as a bending line to bend and deform the entire flat wall to absorb the reduced pressure generated.

This curved depression deformation of the entire flat wall makes the ridge line formed between the tapered wall of the concave portion and the circumferential groove a bending line, and the side wall and the groove of the circumferential groove on the side opposite to the flat wall side. It is achieved by using the connecting portion with the bottom wall and the both end portions of the flat wall as curved deformation points.

As described above, the curved depression deformation of the entire flat wall for absorbing the reduced pressure is caused by the ridge line formed between the tapered wall of the recess and the circumferential groove and the circumferential groove on the side opposite to the flat wall side. The deformation is always constant because it is caused by the constant curved deformation of the connecting portion of the groove side wall and the groove bottom wall and the specified end points of both sides of the flat wall. At the same time, in the prior art, since the ridge line as a bending line is formed in the circumferential groove portion that strongly prevented the occurrence of the curving depression deformation of the flat wall, the curving depression deformation of the flat wall easily occurs. It can be done.

If the ridgeline formed between the tapered wall of the recess and the circumferential groove is located close to the side end view of the flat wall by making the recess horizontally long, almost the entire flat wall is bent and deformed. In addition, the ridge line, which is one place for causing the flat wall to be curved and depressed, and the both ends of the flat wall, which is another place for causing the flat wall to be transformed, are located close to each other. As a result, it becomes easier for the curved wall of the flat wall to deform.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an overall front view of a 2-liter PET biaxially stretched blow-molded bottle body 1 in which a body portion 2 has a substantially rectangular tubular shape with a bottom.

At the upper end of the body portion 2, a short cylindrical mouth portion 9 is provided with a thread and a flange projectingly provided on the outer peripheral surface via a shoulder portion 8 having a polygonal cylindrical frustum shape which is reduced upward. Is erected.

An upper circumferential groove 3 is recessed around a portion slightly above the center of the body 2 in the height direction, and a lower circumferential groove 3 is formed at the lower end of the body 2. There are also sunken depressions.

The two circumferential grooves 3 have a groove bottom wall 3b and the groove bottom wall 3b.
and a pair of groove side walls 3a inclined from the upper and lower edges of b in a direction of increasing the mutual distance outwardly.
It exerts the effect of increasing the buckling strength of the body 2.

The flat wall portions of the body portion 2 which are vertically divided into two by the upper circumferential groove 3, that is, the eight flat wall portions, each have a panel wall portion at the center for absorbing reduced pressure. 5 is formed (see FIGS. 1 and 2), the body 2
Since the flat tubular wall portion sandwiched between the upper and lower circumferential grooves 3 of the long side tubular wall portion of is the flat wall 4 (see FIG. 1),
Will be provided in a pair in front of and behind the body 2.

A horizontally elongated upper recess 6 is formed in a portion from the center of the upper end of both flat walls 4 to the groove bottom wall 3b of the upper peripheral groove 3.
Similarly, a horizontally elongated lower recess 6 is recessed in a portion from the center of the lower end of both flat walls 4 to the groove bottom wall 3b of the lower circumferential groove 3.

Each recess 6 has a tapered wall 6a extending outward.
And a bottom wall 6b continuous with the inner end of the tapered wall 6a to form the bottom of the recess 6, and the tapered wall 6a portion located in the flat wall 4 portion is a groove of the circumferential groove 3. Bottom wall 3b
Since the height of the taper wall 6a is larger than that of the taper wall 6a located at the portion, both side edges, which are continuous portions with the flat wall 4, are
The tapered wall 6a located in the groove bottom wall 3b portion of the circumferential groove 3 is located more laterally than both side edges of the taper wall 6a connected to the groove bottom wall 3b. The pair of ridge lines 7 formed as a continuous portion between the groove 3 and the side wall 3a of the peripheral groove 3 is inclined (see FIG. 1) in a direction of expanding from the peripheral groove 3 toward the flat wall 4.

In the illustrated embodiment, the recess 6 is the panel wall 5
Since the flat wall 4 is formed to have a width substantially equal to that of the flat wall 4 due to the reduced pressure absorption, the flat wall 4 portion provided with the panel wall portion 5 is deformed as a whole. The depression deformation that absorbs the reduced pressure is achieved in a constant form without being affected by the depression deformation of the flat wall 4.

The height and width of the upper recess 6 is set to a value that allows a fingertip to intrude with a sufficient margin, and the recess 6
By setting the depth of the upper end of the upper part of the body portion 2 to a value at which the intruding fingertip can be strongly caught.
The central part can be made to function as a grip, and the bottle body 1
Can be handled well.

[0028]

EFFECTS OF THE INVENTION Since the present invention has the above-mentioned structure, it has the following effects. Absorption of the reduced pressure generated in the bottle is not only due to the depressed deformation of the panel wall provided on the cylinder wall of the body, but also due to the almost entire depressed deformation of the flat wall provided with this panel wall. Is also achieved, and therefore, a very large vacuum absorption capacity can be exhibited.

The flat wall that is depressed and deformed to absorb the reduced pressure is
By the action of the ridgeline formed by providing the recess,
It can always be deformed in a constant and stable manner and easily, so that the depression deformation for the decompression absorption of the panel wall can also be achieved in a consistent and stable manner, so that the decompression absorption can be achieved. The recessed deformation that occurs in 1) is achieved with a good appearance, and the appearance of the bottle is not impaired.

Since the concave portion is formed without impairing the basic structure of the circumferential groove, the buckling strength reinforcing effect exerted by the circumferential groove is not deteriorated, and thus the buckling strength is not lowered. It is possible to provide a bottle having a high vacuum absorption capability.

Since a concave portion and a peripheral groove are newly added to the conventional bottle and the concave portion and the peripheral groove can be easily formed without difficulty, the conventional molding technique can be used as it is. It can be carried out easily.

[Brief description of drawings]

FIG. 1 is an overall front view showing an embodiment of the present invention.

FIG. 2 is an overall side view of the embodiment shown in FIG. 1 with a bottom portion omitted.

FIG. 3 is an enlarged vertical sectional side view of an upper concave portion in the embodiment shown in FIG.

FIG. 4 is an enlarged vertical sectional front view of a circumferential groove portion in the embodiment shown in FIG.

FIG. 5 is a plan sectional view taken along the line AA in FIG.

[Explanation of symbols]

 1; Bottle body 2; Body part 3; Circumferential groove 3a; Groove side wall 3b; Groove bottom wall 4; Flat wall 5; Panel wall part 6; Recessed part 6a; Tapered wall 6b; Bottom wall 7; Ridge line 8; Shoulder part 9; Mouth

Claims (4)

[Claims] 1. A flat wall (4) having a panel wall (5) for absorbing reduced pressure is formed on a body (2) having a bottomed cylindrical shape,
The body portion is continuously connected to both upper and lower edges of the flat wall (4).
A circumferential groove (3) is recessed around (2), and is outwardly provided at a portion from the central portion at the upper and lower ends of the flat wall (4) to the groove bottom wall (3b) of the circumferential groove (3) facing each other. A synthetic resin bottle body in which a concave portion (6) composed of an expanding taper wall (6a) and a bottom wall (6b) is depressed. 2. The left and right ridge lines (3) formed between the taper wall (6a) of the recess (6) and the groove side wall (3a) of the peripheral groove (3) by making the recess (6) horizontally long. The synthetic resin bottle body according to claim 1, wherein 7) is located near the side ends of the opposing flat walls (4). 3. The body (2) has a bottomed parallel rectangular tube shape,
The synthetic resin bottle according to claim 1 or 2, wherein at least a pair of flat plate-shaped cylindrical wall portions of the body portion (2) facing each other are flat walls (4). 4. The upper circumferential groove (3) is provided in the center of the body (2) in the height direction, and the lower circumferential groove (3) is provided at the lower end of the body (2). Item 1. A synthetic resin bottle body according to item 1 or 2 or 3.