JPH05310239A - Biaxially drawn blow-molded container - Google Patents

Abstract

PURPOSE:To provide a biaxially drawn blow-molded container, an uneven part provided on the body of which is not greatly deformed to a degree to cause the reduction of strength, even when a hot filling is performed. CONSTITUTION:A plurality of recessed parts 12 which extend in the longitudinal direction are formed while being arranged in the peripheral direction, at least from the central part to the lower part of a body part 8 of a container 1. The bottom surface part of each recessed part 12 has three panel parts such as an upper panel part 12a, central panel part 12b and lower panel part 12c. For the present biaxially drawn block-molded container, the central panel part 12b is more recessed than the other panel parts. Preferably, the center of the central panel part 12b has a shape which is slightly curved outward, and the panel structure absorbs the pressure reduction at the time of pressure reduction of the inside of the container 1 by recessing the curved center of the central panel part 12b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container manufactured by biaxial stretch blow molding, and particularly to a heat resistance which does not cause permanent deformation due to bulging of a recess provided in a body during hot filling. Deformable container.

[0002]

BACKGROUND OF THE INVENTION Biaxially stretched blow-molded bottles made of saturated polyester resin represented by polyethylene terephthalate have excellent transparency and surface gloss, and are beautiful and have a gas barrier. Excellent in water resistance, water impermeability, content resistance and storage stability. Further, additives such as plasticizers and stabilizers do not generate toxic gas, generate little heat during combustion, and do not damage the furnace. Therefore, it is widely used in various drinking water, seasonings, containers (bottles) for foods such as alcoholic beverages, and the like.

Recently, a large biaxially stretch blow-molded container has come to be used as a container for beverages such as juice. In such a large container, for example, FIG.
Like the containers 4 and 5 shown in (a) and (b), the body is provided with uneven parts to support the weight of the contents and to resist the external force applied when the filled container is transported. Improves strength. In the container 4 of FIG. 4 (a), the plurality of vertically extending recesses 41 are formed so as to be arranged in the body circumferential direction, and thus the protrusions 42 are formed between the recesses 41. As shown in FIG. 5 (a), which is a partial cross-sectional view taken along line XX of FIG. 4 (a), in such a container 4, the concave portion 41 between the convex portions 42, 42 is substantially flat. It is generally a simple curved surface. Also in the container 5 of FIG. 4 (b), the bottom surface of the recess 51 is similarly substantially flat and has a simple curved surface.

FIGS. 5 (b) and 5 (c) show a cross section of the recess 41 of the container 4 along the vertical YY line and a cross section of the recess 51 of the container 5 along the vertical ZZ line, respectively. As shown in these figures, the bottom surface of the recess 41 of the container 4 has one smooth curved surface. On the other hand, in the concave portion 51 of the container 5, a bent portion 54 is formed substantially in the middle thereof, and smooth panel portions 51a and 51b exist above and below the bent portion 54, respectively.

By the way, in recent years, so-called hot fill has been performed in which a polyester container made by such biaxial stretch blow molding is filled with a liquid such as juice kept at a temperature of 80 to 95 ° C. When a beverage such as juice is hot-filled into a conventional thin plastic container 4 or 5 as shown in FIG. Since the space tends to expand, the internal pressure increases, and the recessed portion provided in the body of the container may expand outward and reversely deform. For example, in the container 4 described above, FIG.
As shown by the broken line in (a), the concave portion 41 of the container swells. When the concave portion is thus deformed, even if the contents are cooled and the internal pressure of the container is reduced, the swollen portion remains as it is, which deteriorates the appearance of the container and reduces the commercial value. Further, the deformation also lowers the strength of the container body, which causes a problem in transportation.

Also, in the case of the container 5, the recess 52 often bulges for the same reason. As shown in FIGS. 4 (b) and 5 (c), even if the recess provided in the body is simply formed into a structure composed of two upper and lower panel portions,
There is little effect of preventing the bulging of the concave portion against the increase in the pressure inside the container immediately after hot filling.

Therefore, it is an object of the present invention to provide a biaxially stretch blow molded container in which the uneven portion provided on the body of the container does not significantly deform so as to reduce the strength even when hot filling is performed. is there.

[0008]

As a result of earnest research in view of the above object, the present inventor has formed a plurality of recesses in the body of a container in the longitudinal direction, and the substantially central portion of the recess is a flat surface or a convex portion. If the curved surface is formed and the central part of the recess is recessed deeper than the upper and lower parts, the recess does not bulge and invert even when hot filling is performed, and a good container appearance can be maintained. Was discovered, and the present invention was conceived.

That is, the biaxially stretch blow-molded container of the present invention is formed with a plurality of longitudinally extending recesses arranged in the circumferential direction at least in the portion from the center to the lower part of the body of the container. The bottom surface of each recess has at least three upper, middle, and lower panel portions, and the middle panel portion is more recessed than the other panel portions.

[0010]

Embodiments and Functions FIG. 1 is a front view showing a biaxially stretch blow molded container according to an embodiment of the present invention.

In the present embodiment, the biaxially stretched blow molded container 1 integrally formed by blow molding using a plastic such as polyethylene terephthalate has a mouth portion 6.
A shoulder part 7, a body part 8 and a bottom part 9, and a mouth part 6,
The shoulder portion 7 and the bottom portion 9 have the same shape as the conventional biaxially stretch blow molded container.

In the present embodiment, a waist portion 16 is formed along the circumference at a portion slightly above the center of the body portion 8, and the body portion above the waist portion 16 smoothly extends from the shoulder portion 7. It has a continuous smooth wall surface. On the other hand, this waist 16
In the lower torso part, there are a plurality of recesses each having a shape extending in the vertical direction.
12 are formed so as to be arranged in the circumferential direction.
A convex column portion (hereinafter referred to as a convex portion) 14 extending in the vertical direction is formed between the 12 and 12.

Each recess 12 has three panel portions 12a, 12b.
, 12c, and the central panel portion 12b is recessed to the innermost side. In this embodiment, the central panel portion 12
b is formed smaller than the other panel portions 12a and 12c. It should be noted that the three panel portions 12a, 12 in each recess 12 are
The sizes of b and 12c are the same.

FIG. 2 is a partial sectional view taken along the line AA of FIG. As can be seen from this figure, in the portion below the constricted portion 16 provided in the body portion 8 of the container 1, there are wall surfaces in which the convex portions 14 and the concave portions 12 alternate. In FIG. 2, only half of the AA cross section of the container 1 is shown, but as can be easily inferred from this figure, the container 1 of this embodiment has six convex portions 14.
And 6 recesses 12 are alternately repeated to form a body structure.

As can be seen from FIG. 2, the panel portion 12b of the concave portion 12 has a convex curved surface shape such that the central portion thereof slightly bulges outward. Further, both side surface portions 12d of the central panel portion 12b have a steeper slope than the side surface 12e of the entire concave portion.

FIG. 3 is a partial sectional view taken along the line BB of FIG. Here, the right side of the container wall 10 is the inside of the container. As can be seen from this figure, the central panel portion 12b of the three panel portions of the recess 12 is located at the innermost position. Also,
Each of the panel portions 12a, 12b and 12c has a structure in which the central portion thereof bulges outward.

When the recess 12 as described above is formed in the body, even if the internal pressure of the container increases, the recess does not deform so as to bulge outward as shown by the broken line in FIG. That is, since the substantially central portion of the recess 12 is relatively deep, it is possible to sufficiently resist an increase in internal pressure after hot filling. In particular, as in the present embodiment, if both side surface portions 12d, 12d of the central panel portion 12b, which has become deeper by one step, are made to have a steep inclination, it is possible to reliably prevent the bulge inversion of the concave portion. The deepest central panel portion 12b serves as a horizontal rib that is wavy in the circumferential direction of the body,
Improves the mechanical strength of the body.

The container 1 of the present embodiment not only prevents the container body from bulging and deforming immediately after hot filling, but also does not impair the appearance of the container when the filled contents are cooled and the internal pressure of the container is lowered. Also, it has a body panel structure that is deformed so as to cancel the reduced pressure without lowering the mechanical strength of the container. Each panel portion of the recess 12 serves as the reduced pressure deformation portion.

As can be seen from FIGS. 2 and 3, each panel portion 12a, 12b and 12c of the recess 12 has a convex shape with its central portion curved outward. This panel structure is
When the contents in the container are hot-filled and capped and then cooled and the internal pressure of the container is lowered, the container is deformed as shown by broken lines in FIGS. 2 and 3, respectively. In this way, the curved portion of the central portion of the recess is deformed inward to absorb the reduced pressure in the container. At this time, the central portion of the curved recess is smooth,
Since the container does not have an unnatural shape and is deformed, the appearance of the container does not feel uncomfortable.

The biaxially stretched blow molded container of the present invention is preferably made of a thermoplastic such as polyethylene terephthalate.

The biaxial stretch blow molding machine of the present invention has been described above with reference to the accompanying drawings. However, the present invention is not limited to this, and various modifications can be made without departing from the concept of the present invention. it can. For example, each panel portion of the recessed portion provided in the body portion may have a simple curved surface or a flat structure instead of the reduced pressure absorption panel structure, or some of the panel portions may serve as the reduced pressure deformation portion.

In the above embodiments, the container in which the six concave portions and the six convex portions are alternately arranged in the body circumferential direction has been described, but the number of the concave portions may be appropriately changed. Also,
The size and the like of the concave portion may be appropriately changed according to the design of the container.

[0023]

As described above in detail, in the present invention, the concave portion provided in the body portion of the container is formed by three or more panel portions, and the panel portion located substantially at the center thereof is made deeper. As a result, even if the internal pressure of the container rises after hot filling, the concave portion provided in the body does not undergo deformation such as expansion and inversion.

Further, according to the present invention, the concave portion may have a panel structure in which the central portion is slightly curved outward. Such a panel structure serves as a deformed portion at the time of depressurization, and when the internal pressure of the container is reduced, the curved central portion is recessed to naturally absorb the depressurization.

The container of the present invention can be used as various containers for hot filling.

[Brief description of drawings]

FIG. 1 is a front view showing a biaxially stretch blow molded container according to an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view taken along line AA of the biaxially stretch blow-molded container shown in FIG.

FIG. 3 is a partial cross-sectional view of the biaxially stretch blow-molded container shown in FIG. 1, taken along the line BB.

4A and 4B are front views showing an example of a conventional biaxially stretch blow-molded container.

5 (a) is a partial cross-sectional view of the biaxially stretch blow-molded container shown in FIG. 4 (a), taken along line XX, and FIG. 5 (b) is shown in FIG. 4 (a).
4C is a partial cross-sectional view of the biaxially stretch blow-molded container shown in FIG. 4, taken along line YY, and FIG. 4C is a partial cross-sectional view of the biaxially stretched blow-molded container shown in FIG. Is.

[Explanation of symbols]

 1, 4, 5 Container 6 Mouth 7 Shoulder 8 Body 9 Bottom 10 Container Walls 12, 41, 51 Recesses 12a, 12b, 12c Recessed panel part 14, 42 Convex part 16 Constricted part

Claims (3)

[Claims] 1. A biaxially stretched blow-molded container, wherein a plurality of longitudinally extending recesses are arranged in a circumferential direction from at least a central portion of a body of the container to a lower portion thereof, and a bottom surface portion of each recess is formed. At least the top, middle and bottom 3
A biaxially stretch blow-molded container having two panel portions, wherein the middle panel portion is more recessed than the other panel portions. 2. The biaxially stretch blow-molded container according to claim 1, wherein the central panel portion of the recess has a shape in which the central portion is curved outward slightly, and the central portion is compressed when the pressure inside the container is reduced. A biaxially stretched blow-molded container having a panel structure that absorbs reduced pressure by denting the curved central portion of the panel portion. 3. The biaxially stretch blow-molded container according to claim 2, wherein the panel portions other than the middle panel portion of the recess also have a reduced pressure absorption panel structure in which the central portion is curved outward slightly. A biaxially stretched blow-molded container.