JP3420818B2 - Biaxial stretch blow molded container - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biaxially stretch blow molded container, and more particularly to a wall structure of the biaxially stretch blow molded container.

[0002]

As is well known, for example, a container (hereinafter referred to as a bottle) biaxially stretch-blow molded using polyethylene terephthalate (PET) has gas barrier resistance,
It has many advantages such as transparency, toughness and hygiene.

By the way, one of the bottles obtained by the biaxial stretch blow molding is called a heat resistant bottle.
This heat-resistant bottle is a bottle that can be filled with contents such as juice that has been heated to a high temperature for sterilization.

However, in such a bottle, when the content is cooled, the volume of the content is reduced and the inside becomes a decompressed atmosphere, so that the bottle wall portion may be contracted and deformed. Deformation due to such volume reduction and decompression leads to a change in the external shape of the bottle, which impairs the commercial value of the bottle.

Therefore, as a measure against such volume reduction and decompression, a structure is adopted in which only a part of the wall portion is deformed by the volume reduction and decompression to prevent the external shape of the bottle from being deformed. .

This structure is called a decompression panel, and a structure in which a plurality of vertically long concave portions which are recessed toward the inside of the bottle are provided on the surface of the wall of the bottle is usually used. As a result, when the volume-reduced pressure is generated, only the concave portion is deformed under reduced pressure, so that it is possible to prevent the shape change in other portions of the bottle.

On the other hand, some bottles obtained by the above-mentioned biaxial stretch blow molding have a rectangular cross-sectional shape in terms of design. The cross section in this case is
The cross section of the bottle in the direction perpendicular to the vertical direction.

[0008] Then, has been made is possible to provide a vacuum panels for such a rectangular cross-section of the bottle, the length
In the case of a square, the long side that is easily bent and deformed
In this case, pressure reducing panels are formed on all four sides .

There is also a rectangular bottle of this type in which a chamfer is formed at a position where each side intersects and each side is continuous. The reason for forming the chamfered portion is to secure the strength at the corner portion of the bottle, that is, at the position where the sides forming the wall surface intersect. Therefore, the cross-sectional shape of such a bottle is octagonal.

[0010]

However, among the above-mentioned containers, in the case of a square container, the shrinkage deformation during volume reduction and decompression is almost evenly performed on each side, so that the change in the external shape is small. In the case of a bottle having a different side length such as a rectangle, the wall surface of the short side may bulge and the appearance shape may change.

That is, the long side having a long span is easily contracted and deformed by providing the pressure reducing panel, but when the long side is deformed, the short side is swollen. This is especially noticeable in the lower body where the hydraulic pressure tends to increase.

It is considered that the reason for this is that the weight of the contents or the pressure applied from the shrunk wall portion and the thermal deformation are also applied and the contents bulge outward.

On the other hand, the inventor tried to form grid-like ribs or vertical ribs in the short side, but the short side itself swelled, and it was impossible to suppress the change in outer shape.

Such short side bulging also occurs when the vertical side is manually gripped, for example.

Therefore, an object of the present invention is to provide a biaxially stretched blow-molded container having a structure that does not easily deform in view of the above problems in the conventional biaxially stretched blow-molded container.

[0016]

In order to achieve this object, the invention according to claim 1 has a vertical axis direction and a horizontal axis direction.
By being stretched, there is an opening on one side in the machine direction and another on the other side.
Each bottom is formed and has a rectangular cross section
In the biaxially stretch blow-molded container having a wall portion which are, on
It is installed at the position where the wide and narrow walls of the cross section intersect.
Chamfer, which has a shorter length than the above walls.
And the vertical direction from the shoulder that transitions from the opening to the side wall
At the distance (L1) in the vertical direction from the heel near the bottom
And the distance (L2) is set to L2> L1.
That at the location, a bottomed groove formed along the circumferential direction, the
It is installed on the wall with a distance (L2) to reduce the volume and reduce the pressure.
It has the above-mentioned distance (L1) with the decompression deformation part which sometimes contracts and deforms.
The indentation along the vertical direction in the chamfer on the wall side
Characterized in that it comprises a first rib concave numbers,.

The invention according to claim 2 is the same as in claim 1.
Te, the reduced pressure deformation portion, the wall portion having the distance (L2)
Is installed on the wide wall of the
The second wall provided on the entire narrow wall portion
Ribs, and the second ribs have narrow walls and the chamfers.
It is characterized in that it extends to the chamfered portion beyond the corner where the rib intersects .

[0018] According to a third aspect of the invention, according to claim 2, said second rib is characterized by being formed by concave recesses inwards.

[0019]

According to a second aspect of the invention, a chamfered portion continuous with each side is formed at an intersection of the wide wall portion and the narrow wall portion, and the chamfered portion has an end portion in the extension direction . ribs of is formed continuously with the narrow wall areas. Moreover, since the chamfered portion is shorter than each side, the bending strength on this side is stronger than the other sides. Therefore, the chamfered portion becomes a reinforcing portion on each side. Therefore, unlike the conventional one, the second rib is not provided only in the plane where the bending deformation occurs, and the second rib is continuously provided even to the chamfered portion that is a portion strong against bending deformation. Bending deformation of the narrow wall portion having the corner between the chamfered portion and the narrow wall portion as a fulcrum is suppressed. In other words, the second rib that suppresses bending bending of the side is
Since it is reinforced by the chamfered portion which is relatively less deformed, it is possible to prevent the deformation of the narrow wall portion which is continuous with the second rib.

According to the invention of claim 1 , the upper body portion and the lower body portion are formed with the recess formed based on the distance from the opening and the bottom portion as boundaries, and the upper body portion is chamfered together with the pressure reducing panel. A plurality of first ribs in the longitudinal direction of the part, especially concave first
1 rib is formed. Therefore, since there is no protruding portion on the upper body portion, the label can be attached.

[0021]

The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sectional view of a biaxially stretch blow molded container (hereinafter referred to as a bottle) according to the present invention.

The bottle 10 shown in FIG. 1 is formed into a cross-sectional shape having different lengths and widths by biaxial stretch blow molding using, for example, polyethylene terephthalate (PET).

That is, in FIG. 1, the lateral side 12 corresponding to the wide wall portion exposed to the front is located in the direction perpendicular to this and corresponds to the narrow wall portion as shown in FIG. It is longer than the vertical side 14. And each of these sides
The chamfered portions 16 located at the intersections and having a dimension shorter than each side are continuous.

Bottle 10 having such a cross-sectional shape
In the upright state shown in FIG. 1, a groove 18 is formed at a position substantially corresponding to the center, and an upper body 20 and a lower body 22 are formed.
It is divided into and. The upper body 20 and the lower body 22
With respect to the members having the same functions in and, the reference numeral attached to the lower body 22 side is shown by three digits.

In the groove 18, the distance (L1) from the shoulder portion 10A that moves from the lip portion to the side wall of the bottle 10 and the distance (L2) from the heel portion 10B that moves from the side wall to the bottom portion have a relationship of L2> L1. It is formed at a position set to “1” to prevent buckling deformation of the bottle 10 in the vertical direction.

On the other hand, the lower barrel 22 which receives a large amount of hydraulic pressure from the filled contents has a shrinking deformation portion when the volume reduction of the contents occurs and a narrow wall portion when the deformation shrinks. A structure is provided to prevent bulging toward.

That is, in FIG. 2, on the horizontal side 112 corresponding to the long side of the wall surface of the lower case 22, there is provided a pressure reducing panel 124 having a vertically long concave portion having a well-known structure.

On the other hand, on the inner wall surface of the vertical side 114 corresponding to the narrow wall portion, as shown in FIG. A rib 26 is provided. The rib 26 is shown in FIG.
As shown in, it is extended horizontally.

The rib 26 is formed as a concave portion slightly entering from the peripheral wall of the bottle 10 and constitutes a reinforcing portion against bending deformation of the vertical side. Therefore, the vertical side 114 is
The ribs 26 increase the cross-sectional rigidity, and both ends are supported by the chamfered portions 16 which are relatively stronger in bending strength than these sides.

On the other hand, like the lower body 22, the upper body 20 is provided with a pressure reducing panel 24 on the lateral side 12 corresponding to the long side.

By the way, the upper body 20 may be used, for example, as a place for sticking a label of a product.
Therefore, if the ribs are formed in the same manner as the lower case 22,
Irregularities are considerably formed on the surface of the corner portion of the upper body 20, and the label portion becomes uneven, impairing the appearance.

Therefore, in this embodiment, in the chamfered portion 16 formed on the upper body 20, a plurality of concave ribs 28 that are recessed inward in the vertical direction are arranged.

Since the present embodiment is constructed as described above,
When the volume of the filled contents is reduced and the pressure is reduced,
The lateral sides 12 and 112 corresponding to the wide wall portions cause inward protruding deformation of the pressure reducing panel. On the other hand, the decompression panel 2
Bottle 10 with internal volume reduced by 4,124
Causes the vertical sides 14 and 114 corresponding to the narrow wall portion to bulge. However, in this case, the vertical side 1 14 rib 26 formed over the entire area and the chamfered portion 16 of the deflection deformation of the lateral sides 1 12 is suppressed. In addition, the upper body 20 is reinforced by the recesses formed in each chamfer. Moreover, since there is no protrusion on the surface of the upper body 22, it does not hinder labeling.

[0035]

As described above, according to the present invention, in a bottle having a rectangular cross section composed of wide and narrow walls, a decompression panel is provided on the relatively flexible wide wall, and a narrow width is provided. A chamfered portion that is continuous with this wall portion is formed in the wall portion of the above, and a rib whose end in the extension direction is located in this chamfered portion extends over the entire narrow wall portion. As a result, the narrow wall portion can have rigidity against bending with the corner of the chamfered portion as a fulcrum, and thus does not bulge outward. Therefore, even when the volume is reduced and the pressure is reduced, the external shape of the bottle does not change and the commercial value is not impaired.

Further, it is possible to prevent the short side from being deformed when it is gripped, and to prevent the content liquid from splashing out due to the deformation at the time of gripping.

[Brief description of drawings]

FIG. 1 is a sectional view showing a bottom structure of a biaxially stretch blow molded container according to the present invention.

FIG. 2 is a cross-sectional view taken along the arrow BB in FIG.

FIG. 3 is a view in the direction of the arrow C in FIG.

FIG. 4 is a cross-sectional view taken along arrow AA in FIG.

[Explanation of symbols] 10 bottles 12 Sides corresponding to wide walls 14 Vertical side corresponding to narrow wall 16 chamfer 20 upper torso 22 Lower torso 24 Decompression deformation part 26 ribs 28 Concave rib

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B65D 1/02 B29C 49/08

Claims (3)

(57) [Claims] 1. A biaxial shaft having a wall portion formed in a rectangular cross-sectional shape by being stretched in the longitudinal axis direction and the transverse axis direction to form an opening in one of the longitudinal directions and a bottom portion in the other direction. In the stretch blow-molded container, the wide wall portion and the narrow wall portion of the cross section are provided at positions intersecting with each other, and a chamfered portion having a length shorter than each of the wall portions, and from the opening to the side wall. Along the circumferential direction, a distance (L1) in the vertical direction from the transitional shoulder portion and a distance (L2) in the vertical direction from the heel portion near the bottom are set in a relationship of L2> L1. The bottomed groove formed as described above, the wall portion having the distance (L2), and the pressure reducing deformation portion that contracts and deforms when the volume is reduced and the chamfer portion on the wall portion side having the distance (L1) is formed. Longitudinal direction
And a plurality of concave first ribs that are recessed inward along the biaxially stretched blow-molded container. 2. The reduced pressure deformable portion according to claim 1, wherein the reduced pressure deformable portion has a wall portion having the distance (L2).
Provided in a wall portion of the Chide wide, a second rib provided on the narrow wall whole among the wall portion having the distance (L2), said second rib is narrow wall A biaxially stretch blow-molded container, wherein the chamfered portion extends beyond a corner where the chamfered portion intersects the chamfered portion. 3. The biaxially stretch blow-molded container according to claim 2, wherein the second rib is formed as a concave portion that is recessed inward.