JP2001180635A - Blow-molded thin bottle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thin bottle for which reinforcement is applied to a shoulder part thereof while a trunk part thereof is also reinforced. SOLUTION: For a thin bottle composed of a mouth part, a shoulder part, a trunk part and a bottom part and made up by biaxially stretched blow molding, the shoulder part is reinforced with a plurality of spiral ribs provided at equal intervals entirely around the shoulder wall while the trunk part is reinforced with a plurality of transversely-extending depressed ribs provided at equal intervals in the vertical direction around the circumferential surface thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a reinforcing rib provided on a shoulder portion of a thin-walled bottle, in particular, a shoulder portion of the bottle.

[0002]

2. Description of the Related Art In recent years, the reuse of plastic molding materials has been promoted along with the saving of plastic molding materials, and it has become necessary to reduce the thickness of bottles in order to crush and collect waste bottles. Thin bottles that can be made are well known.

[0003] In the case of a PET bottle, as a thin-walled bottle that can be extremely easily crushed, the resin weight per unit volume is in the range of 0.033 to 0.045 g / ml, and the thickness of the body is about 0.1 mm. Is a commercially available bottle. In the case of a thin-walled bottle formed by stretching PP,
Bottles having a resin weight per unit capacity of 0.024 g / ml and a body thickness of 0.1 mm have been conventionally marketed.

[0004]

The conventional container is made of PE
In any case of T, PP, etc., the container mouth, especially the neck ring, was improved to reinforce the opening and closing of the cap. However, in opening and closing the cap, the general consumer is not always limited to grasping the opening of the container, and usually grasps the shoulder from the upper end of the body to open and close the cap. Therefore, there is a problem that the shoulder is twisted and the screw tightening force and the screw loosening force do not work effectively.

[0005] Further, when the thickness of the bottle mouth is reduced to save the molding material, the thickness of the shoulder itself is also reduced.
The problem that the opening and closing force of the screw did not work and it could not be opened and closed properly came to occur.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a thin-wall bottle in which a shoulder is reinforced together with a body.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a thin-walled biaxially stretched blow-molded bottle comprising a mouth portion, a shoulder portion, a body portion and a bottom portion. Thus, a configuration is adopted in which a plurality of spiral ribs are arranged at equal intervals around the shoulder wall.

A thin-walled blow-molded bottle according to another embodiment is a thin-walled biaxially stretched blow bottle having a mouth portion and a shoulder portion, a body portion and a bottom portion, wherein the shoulder portions are equally spaced around the entire circumference of the shoulder wall. It is characterized in that two arc-shaped curved lines that intersect with the curving directions opposite to each other are set as ridgelines, and shallow quadrangular pyramid-shaped concave portions are arranged in the range of the intersecting line so as to be continuous vertically and horizontally. Adopt configuration. Further, in addition to the above-described respective configurations, a configuration is adopted in which the trunk portion is reinforced by a reinforcing rib.

The blow-molded bottle has a resin weight per unit capacity of 0.004 to 0.025 g / ml using PET or PP as a material resin. And a configuration characterized by stacking EVOH or Ny using PET or PP as a base material.

[0010]

Next, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS.
The bottle A includes a mouth 1 and a shoulder 2, a body 3 and a bottom 4 having a circular cross section, and is formed of PET, PP, or another hard resin. A screw 5 and a neck ring 6 are formed on the outer periphery of the mouth 1.

On the outer periphery of the shoulder portion 2, spiral ribs 7 are arranged at equal intervals as viewed from above, on a curved curve extending in a spiral shape so as to radiate in a spiral shape. As shown in FIG. 3, the spiral rib 7 is formed of a top portion 8 and a valley portion 9, and the wall surface of the shoulder portion 2 is formed by a curved surface connected from the valley portion 9 to the top portion 8 a of the adjacent spiral rib 7 a. .

The body 3 has a circular cross section, and as shown in FIG. 1, a plurality of concave ribs 1 extending laterally over the entire circumference.
0 are arranged at equal intervals above and below. The bottom 4 includes a bottom end wall 11 and a bottom wall that is recessed upward, and has a plurality of radially provided ribs (not shown).

Next, the blow molding of the bottle and the amount of resin will be described. In the case of PET, biaxial stretching blow molding was performed using a preform as in a known method. The outer diameter of the mouth portion was set to 20 mm, and a bottle of 500 ml was formed with a preform weight of 2 to 12.5 g.

The resin weight per unit volume of the bottle is
Although it is 0.025 to 0.004 g / ml, the weight may be around 0.04 g / ml, as in the conventional case, as long as the shape can be easily maintained and the crushing can be easily performed. In order to further save the resin, the outer diameter and thickness of the mouth are reduced, and the unit weight is set to 0.025 g / ml or less. When the resin weight was close to 2 g, the wall surface became similar to that of the film, but the shape retention as a bottle was maintained, and the shoulder was not twisted and the cap could not be opened and closed.

In the case of PP, similarly to PET, biaxial stretching blow molding is performed using a preform. The preform weighs 2 to 10 g (the weight per unit capacity is 0.004
０．０0.02 g / ml) to form a 500 ml bottle. Conventional weight per unit capacity 0.024 g / m
1, the outer diameter and thickness of the mouth can be reduced as compared with the PP stretch blow container of l, and in the range of the embodiment, the shape retention as a bottle is maintained, the shoulder is twisted, and the cap is opened and closed. There was no inability to do it.

As other resins, PEN (polyethylene naphthalate), HDPE (high-density polyethylene),
PAN (polyacrylonitrile), COC (cyclic olefin copolymer), and COP (cyclic olefin polymer) also have a resin weight of 0.004 to 0.025 g in the same manner as described above.
/ Ml.

Further, EVOH (ethylene / vinyl alcohol copolymer) or Ny (nylon) is laminated using PET, PP, or the like as a material resin, and the resin weight is set to 0.1.
It can be molded in the range of 004 to 0.025 g / ml.

Next, a second embodiment will be described with reference to the drawings. In the present embodiment, the rib shape of the shoulder portion is changed in the previous embodiment, and the other portions are the same. Therefore, the description will be focused on the shoulder portion, and the mouth portion and the trunk portion will be given the same reference numerals with the suffix a. I will explain briefly.

As shown in FIGS. 4 and 5, the bottle Aa has a mouth 1a and a shoulder 2a, a body 3a and a bottom 4a, and is formed of PET, PP or another hard resin as in the previous embodiment. ing. On the outer periphery of the shoulder 2a, two arc-shaped curves 20, 2 which extend in a spiral shape at equal intervals as viewed from the top and which intersect with the curved directions being opposite to each other.
A number of shallow pyramid-shaped recesses 24 are arranged so as to be continuous vertically and horizontally, with 1 as a ridge line, and straight lines 22 and 23 extending in the horizontal and vertical directions from the intersection of the curves 20 and 21 as valley lines. .

The bottle Aa of this embodiment is also formed by biaxial stretch blow molding using a preform in the same manner as the bottle A of the above embodiment, and the resin weight per unit capacity is reduced as in the previous embodiment. However, the shape retention as a bottle and the ease of opening and closing the cap are maintained.

Next, the test results regarding the strength of the shoulder will be described. PET with ribs of each embodiment arranged on shoulder
When a bottle was prepared and the strength of the bottle was compared with that of a bottle without a rib, the following experimental results were obtained. In the experiment, torque was applied by sandwiching the upper part of the trunk and the mouth, and the force when the shoulder was deformed was measured. Assuming that the torque at the time of deformation of the bottle without the rib was set to 100 and compared with the bottle of the embodiment, the following table was obtained.

[0022]

[Table 1]

As is clear from the above table, in the case of the first embodiment in which the helical rib is formed on the shoulder wall, the strength of the shoulder wall is about 20% for tightening the screw, and the strength for loosening the screw is about 20%. About 3
It was found that it increased by 9%. In the case of the second embodiment, since the shape is the same in the left and right directions in the circumferential direction, the strength does not change depending on the direction of the torque, but increased by about 20%. These results did not show a significant difference in the case of PP bottles when PET or PP was used as the base resin and EVOH or Ny was used as the laminated blow.

In each of the above embodiments, a concave rib extending in the lateral direction over the entire circumference is employed as a reinforcing rib of the body portion. However, the horizontal concave rib may be divided into two, or the lateral concave rib may be divided into two parts. Vertical ribs may be provided between the ribs. Furthermore, a corrugated concave rib, a spirally extending concave rib, or a convex rib can also be used, and is not limited to the laterally extending concave rib of the embodiment. Further, the sectional shape of the body may be square or elliptical, and is not limited to a circular bottle.

[0025]

The present invention has the following effects because it is configured as described above. Along with the reinforcement of the torso, a helical rib on the shoulder or a concave portion that is continuous vertically and horizontally reinforces the shoulder, reducing the amount of resin by making the mouth small and thin. In addition, the opening and closing of the cap can be strengthened.

[Brief description of the drawings]

FIG. 1 is a front view of a bottle according to a first embodiment of the present invention.

FIG. 2 is a top view of the bottle.

FIG. 3 is a sectional view of a shoulder taken along line AA in FIG. 1;

FIG. 4 is a front view of a bottle according to a second embodiment.

FIG. 5 is a top view of the bottle.

[Description of Signs] A, Aa bottle 1, 1a mouth 2, 2a shoulder 3, 3a body 4, 4a bottom 5 screw 6, neck ring 7, 7a spiral rib 8, 8a top 9 trough 10 concave rib 11 bottom End wall 20, 21 Curve 22, 23 Straight line 24 Recess

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Shuichi Furushio 310, Minatodai, Matsudo-shi, Chiba F-term in the Matsudo factory of Yoshino Kogyo Co., Ltd. (Reference) 3E033 AA02 BA13 BA15 BA16 BA18 BA21 DC10 EA01 EA03 EA05 FA03

Claims (5)

[Claims] 1. A thin biaxially stretched blow bottle comprising a mouth portion, a shoulder portion, a body portion and a bottom portion, wherein the shoulder portion has a plurality of spiral ribs arranged at equal intervals all around the shoulder wall. Thin blow molded bottles. 2. A thin biaxially stretched blow bottle comprising a mouth portion and a shoulder portion, a body portion and a bottom portion, wherein the shoulder portions intersect at equal intervals around the entire circumference of the shoulder wall with opposite bending directions. A thin blow-molded bottle characterized in that two arc-shaped curves are set as ridge lines, and shallow quadrangular pyramid-shaped recesses are arranged so as to be continuous vertically and horizontally within a range of the intersection line. 3. The thin blow-molded bottle according to claim 1, wherein the body is reinforced by a reinforcing rib. 4. The blow molded bottle is made of PET or PP.
The resin weight per unit capacity is 0.0
The thin blow-molded biaxially stretched bottle according to claim 1 or 2, wherein the weight is from 0.4 to 0.025 g / ml. 5. An EVO using PET or PP as a base material.
The biaxially stretched thin blow molded bottle according to claim 4, wherein H or Ny is laminated.