JPH08207920A - Pressure-proof self-standing bottle - Google Patents

Abstract

PURPOSE: To improve strength against internal pressure and reduce creep deformation arid drop of a fill point by controlling a thickness distribution so that inner thickness of respective bottle parts satisfies a specific relation. CONSTITUTION: At least parts except a mouth 2 and a neck 3 are biaxially drawn, while a holder 4 comprises an arc expanding inward and an arc expanding outward. A plurality of ribs 7 are also placed on the shoulder 4, while a body 8 comprises a lower body part 9B having ribs 1 connected to an approximately cylindrical side wall and an upper body part 9A having no ribs 7. A pinch part 10 having a small diameter is provided at the lower body part, while a bottom 11 is basically a recess swelling downward, and further a plurality of approximately triangular-pyramid-shaped legs 13 are radially provided from the recess. Minimum thickness A of the shoulder 4, minimum thickness B of the upper body part 9A, maximum thickness C of the pinch part 10 and minimum thickness D of the bottom 11 are formed to satisfy such relations that A/B=0.8/1 to 1.1/1, C/B=1/1 to 1.8/1, and D/B=0.7/1 to 1.1/1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biaxially stretched pressure resistant self-supporting bottle made of a thin saturated polyester resin which is suitable for filling carbonated water, soft drink, etc. In other words, by controlling the bottle wall thickness distribution, it has high internal pressure resistance, the deformation at the shoulder and the body is reduced, and the creep deformation at the shoulder and the body and the deterioration of the flavor line are reduced. In addition, the present invention relates to a pressure resistant self-supporting bottle capable of reducing the weight of the bottle.

[0002]

2. Description of the Related Art Conventionally, a pressure resistant self-supporting bottle filled with carbonated drinking water has an open top edge 1 as shown in FIG.
Based on the mouth and neck 2, the substantially spherical shoulder, the cylindrical body, and the concave shape that bulges downward, the leg portion has a substantially triangular truncated pyramid shape that bulges downward from the concave portion. Are composed of a plurality of bottoms radially provided. In addition, recently, a bottle-shaped one having a plurality of ribs and pinches on the body and a shoulder-shaped bottle, which is closer to the design of a glass bottle, is strongly desired by the final consumer. However, when a bottle of the shape is filled with carbonated water and internal pressure is applied, the shoulders, ribs, pinches, and bottom, which are indented inward, have a tensile stress other than tensile stress, such as shear stress, compressive stress, and bending stress. As a result, there is a problem that the stress distribution of the pressure resistant self-supporting bottle collapses, creep deformation increases, and the amount of reduction in the penetration line increases. As a countermeasure against this, it is conceivable to increase the weight of the bottle, but there is a drawback that the cost becomes high.

[0003]

DISCLOSURE OF THE INVENTION The present inventors have endeavored to solve the above-mentioned problems in a biaxially stretch-molded bottle made of a saturated polyester resin, and shafts formed at equal intervals on the shoulders. A plurality of ribs extending in the direction, the body portion is composed of a substantially cylindrical side wall continuous from the shoulder portion, and a lower portion of the body portion having a plurality of ribs continuously formed at equal intervals in the axial direction. It is composed of an upper part of the body without the ribs, has a pinch part of a smaller diameter in the lower part of the body part, and the bottom part is basically a downwardly bulging concave shape. Further, a plurality of substantially triangular truncated pyramid-shaped leg portions bulging downward from the concave shape are provided radially from the concave shape, and the minimum wall thickness A of the shoulder portion and the minimum wall thickness B of the upper portion of the body portion are provided. , The maximum thickness C of the pinch portion and the minimum thickness D of the bottom portion are numbers that satisfy a specific relationship. It has been reached on the type bottle. That is, the present invention, by controlling the thickness distribution of the bottle, has a high internal pressure resistance, the deformation in the shoulder and the body is alleviated, the creep deformation of the shoulder and the body and the reduction of the flavor line. It is an object of the present invention to provide a pressure resistant self-supporting bottle capable of alleviating the above and reducing the weight of the bottle.

[0004]

The first invention of the present invention is as follows:
A biaxially stretched bottle made of a saturated polyester resin, comprising: (a) a mouth-neck portion whose upper end is an open mouth edge portion,
(B) a neck continuous with the mouth and neck, (c) a shoulder continuous with the neck, (d) a trunk continuous with the shoulder, and (e)
It has a bottom portion that closes the lower open portion of the body portion, (a) at least the portion other than the mouth and neck portion and the neck portion is biaxially stretched, and (b) the shoulder portion extends from the neck portion. It is composed of an inwardly projecting circular arc that is connected to the shoulder portion and an outwardly projecting circular arc that is continuous with the circular arc, and
(C) A plurality of ribs formed at equal intervals and extending in the axial direction are installed on the shoulder portion, and (d) the body portion is formed of a substantially cylindrical side wall continuous from the shoulder portion, and continuously formed. A lower part of the body part having a plurality of ribs formed at equal intervals in the axial direction and an upper part of the body part without the ribs, and a pinch part having a smaller diameter among the diameters of the body part is provided in the lower part of the body part. (E) The bottom portion is basically a concave shape that bulges downward, and further, a plurality of substantially triangular truncated pyramid-shaped leg portions that bulge downward from the concave shape radiate from the concave shape. (F) The minimum thickness A of the shoulder portion, the minimum thickness B of the upper portion of the body portion, the maximum thickness C of the pinch portion, and the minimum thickness D of the bottom portion are numbers satisfying the following relations. It is a pressure resistant self-supporting bottle. A second invention of the present invention is that the minimum thickness A of the shoulder portion, the minimum thickness B of the upper body portion, the maximum thickness C of the pinch portion, and the minimum thickness D of the bottom portion. The pressure resistant self-supporting bottle according to the first invention has a density of 1.36 g / cm ³ or more.

The present invention will be described in detail below. FIG. 1 shows a front view of a pressure resistant self-supporting bottle of the present invention. The pressure resistant self-supporting bottle of the present invention is a biaxially stretched bottle made of a saturated polyester resin, and has (a) a mouth neck portion 2 having an open top edge portion 1 and (b) the mouth neck portion. A neck 3 continuous with the portion 2, (c) a shoulder 4 continuous with the neck 3, (d) a body 8 continuous with the shoulder 4, and (e) a bottom 11 for closing the lower opening of the body 8. Having the mouth and neck 1 and the neck 3
The other portions are biaxially stretched, and the shoulder portion 4 extends from the neck portion 3 and extends inwardly to connect with the shoulder portion 4 and has a large radius R1 and an outwardly continuous arc. The shoulder 4 is provided with a plurality of ribs 7 which are formed at equal intervals and extend in the axial direction, the ribs 7 being formed of an arc having a radius R2. The body portion 8 is composed of a substantially cylindrical side wall continuous from the shoulder portion, and has a body portion lower portion 9A having a plurality of ribs 7 continuously formed at equal intervals and a body portion upper portion having no ribs. 9B and has a pinch portion 10 having a smaller diameter than the diameter of the body portion on the lower portion 9B of the body portion, and the bottom portion is basically a downwardly bulging concave shape. A plurality of substantially triangular truncated pyramid-shaped legs that bulge downward are provided radially from the concave shape.

In the present invention, the minimum thickness A of the shoulder portion / the minimum thickness B of the upper portion of the body portion is 0.8 / 1 to 1.1 / 1, preferably 0.85 / 1 to 1. 1/1, and particularly preferably 0.9 / 1 to 1.1 / 1. 0.8 /
When it is 1 or less, the shoulder portion 4 becomes thin and the creep deformation of the shoulder portion 4 becomes large. When it is 1.1 / 1 or more, the shoulder portion 4 becomes thicker and the creep deformation of the shoulder portion 4 becomes smaller, but the lower portion than the shoulder portion 4 becomes thin and the creep deformation of the entire bottle becomes large.

In the present invention, the maximum thickness C / of the pinch portion is
The minimum thickness B of the upper part of the body is 1/1 to 1.8 / 1, preferably 1.1 / 1 to 1.7 / 1, and particularly preferably 1.2 / 1 to 1. It is 5/1. When it is 1/1 or less, the pinch portion 10 becomes thin, and the creep deformation of the pinch portion 10 becomes large. When it is 1.8 / 1 or more, especially the shoulder portion 4 becomes thin and the creep deformation of the shoulder portion 4 becomes large.

In the present invention, the minimum wall thickness D at the bottom / the minimum wall thickness B at the upper part of the body is 0.7 / 1 to 1.1 / 1, preferably 0.8 / 1 to 1.1. / 1, and particularly preferably 0.9 / 1 to 1.1 / 1. When it is 0.7 / 1 or less, the creep deformation of the bottom portion 11 becomes large, and rocker bottom is likely to occur. Body part 8 is 1.1 or more
As a result, the shoulder portion 4 becomes thin and creep deformation increases.

In the pressure resistant self-supporting bottle of the present invention, at least the shoulder part 4, the body part 8 and the bottom part 11 are biaxially stretched, and the minimum wall thickness A of the shoulder part 4 and the minimum wall thickness of the upper part of the body part. B part, pinch part maximum wall thickness C part and bottom minimum wall thickness D
It is preferable that the density of the portion is 1.36 g / cm ³ or more. When the density is less than 1.36 g / cm ³ , the strength obtained by the orientation becomes insufficient and the deformation due to the internal pressure becomes large.

The method for producing a pressure-resistant self-supporting bottle of the present invention comprises heating a preform obtained by injection molding, setting the preform in a molding die having a shape corresponding to a desired bottle shape, and using a stretching rod. After stretching in the longitudinal direction, or at the same time as stretching, blow air is performed to mold the bottle to obtain a pressure-resistant self-standing bottle.

The wall thickness of each part of the pressure resistant self-supporting bottle of the present invention can be controlled by adjusting the shape of the preform, the temperature of the preform during blow molding, the pressure of the drawing rod, and the like.

The resin used for producing the pressure resistant self-supporting bottle of the present invention includes a saturated polyester resin and a copolymer thereof.

The concave portion 12 of the bottom 11 of the pressure resistant self-supporting bottle of the present invention may be substantially hemispherical, or the concave portion 1
A horizontal portion 14 may be provided at the lower end of 2, and a convex portion may be provided at the center of the horizontal portion 14.

The pressure-resistant self-supporting bottle of the present invention is such that when the carbonated beverage is filled, the amount of reduction in the flavor line is small and rocker bottom does not occur.

[0015]

The present invention will be described in detail with reference to the following examples.

Example 1 Polyethylene terephthalate resin (RT-553C) manufactured by Nippon Unipet Co., Ltd. was used and the weight was 4 by an injection molding machine.
9 g of preform was molded. Next, the preform is heated to a biaxial stretch blow molding machine (LB
-01) is a pressure resistant self-supporting bottle (capacity 1505) shown in FIG.
ml) was molded (the numerical values in FIG. 3 indicate the dimensions of each part, and the unit is mm). This pressure resistant self-supporting bottle has 4.
It was filled with 0 volume of carbonated water and stored in an oven at 38 ° C., and the amount of decrease in the taste line and rocker bottom after 1 day and 7 days were evaluated. The evaluation results are shown in Tables 1 and 2.

Comparative Example 1 A pressure resistant self-supporting bottle was molded in the same manner as in Example 1 except that the blow molding conditions were changed so that the shoulder portion was slightly thicker and the biaxial stretch blow molding was performed. (Shown in Figure 3). The evaluation results are shown in Tables 1 and 2. Comparative Example 2 A pressure resistant self-supporting bottle was molded in the same manner as in Example 1 except that the blow molding conditions were changed so that the bottom portion was slightly thicker and the biaxial stretch blow molding was performed (shown in FIG. 3). ). The evaluation results are shown in Tables 1 and 2.

The evaluation method was as follows. 1) Wall Thickness The minimum wall thickness of the shoulder portion, the upper portion of the body portion, and the bottom portion of the pressure resistant self-supporting bottle and the maximum wall thickness of the pinch were measured with a micrometer. 2) Density The density was measured with a density gradient tube using an aqueous solution of calcium nitrate. 3) Amount of drop in the taste line The pressure line of the pressure resistant self-supporting bottle (5 from the tip of the open mouth edge)
The distance at which the liquid level of the contents fell from 0 mm) was measured.
The unit is mm. 4) Rocker bottom If the horizontal part of the bottom part did not protrude from the ground contact surface of the leg part, it was defined as "no occurrence" (good), and if it protruded, "existence" (defective).

[0019]

[Table 1]

[0020]

[Table 2]

[0021]

As is apparent from the above, the pressure resistant self-supporting bottle of the present invention is biaxially stretched from a thin saturated polyester resin which is suitable for filling carbonated drinking water, soft drink, etc. This is a pressure resistant self-supporting bottle, which has a high internal pressure resistance by controlling the bottle thickness distribution, the deformation at the shoulder and the body is eased, and the creep deformation at the shoulder and the body and the taste line A pressure resistant self-supporting bottle that can alleviate the decrease and reduce the weight of the bottle.

[Brief description of drawings]

FIG. 1 is a front view of a pressure resistant self-supporting bottle of the present invention.

FIG. 2 is a front view of a conventional pressure resistant self-supporting bottle.

FIG. 3 is a front view of pressure-resistant self-standing bottles of Example 1 and Comparative Examples 1 and 2 of the present invention.

[Explanation of symbols] 1 Open mouth edge 2 Mouth neck 3 Neck 4 Shoulder 7 Rib 8 Body 9A Body upper part 9B Body lower part 10 Pinch part 11 Bottom part 12 Concave part 13 Leg part 14 Horizontal part R1 Radius of arc that extends inward R1 Radius of arc that extends outward

Claims (2)

[Claims] 1. A biaxially stretched bottle made of a saturated polyester resin, comprising: (a) a mouth neck portion whose upper end is an open mouth edge portion, (b) a neck portion continuous with the mouth neck portion,
(C) a shoulder portion continuous with the neck portion, (d) a body portion continuous with the shoulder portion, and (e) a bottom portion closing a lower opening portion of the body portion, and (a) at least the mouth and neck portion and the The portion other than the neck portion is biaxially stretched, and (b) the shoulder portion extends from the neck portion and extends inwardly extendingly from the neck portion, and the inwardly extending arc extends outwardly from the arc. And (c) a plurality of axially extending ribs formed at equal intervals are provided on the shoulder portion, and (d) the body portion is a substantially cylindrical side wall continuous from the shoulder portion. Consists of a lower part of the body part having a plurality of ribs continuously formed at equal intervals in the axial direction and an upper part of the body part without the ribs, and in the lower part of the body part of the diameter of the body part. (E) The bottom has a concave shape that bulges downward. A plurality of substantially triangular frustum-shaped legs that bulge downward from the concave portion are provided radially from the concave shape, and (f) the minimum thickness A of the shoulder portion, the minimum thickness B of the upper portion of the body portion, and the pinch portion. A pressure resistant self-supporting bottle characterized in that the maximum wall thickness C and the minimum wall thickness D of the bottom are numbers satisfying the following relationship. A / B = 0.8 / 1 to 1.1 / 1 C / B = 1/1 to 1.8 / 1 D / B = 0.7 / 1 to 1.1 / 1 2. The density of the minimum thickness A portion of the shoulder portion, the minimum thickness B portion of the upper body portion, the maximum thickness C portion of the pinch portion, and the minimum thickness D portion of the bottom portion is 1. The pressure resistant self-supporting bottle according to claim 1, which has a weight of 36 g / cm ³ or more.