JPH0331692Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to the structure of a biaxial stretch blow-molded bottle made of synthetic resin such as polyethylene terephthalate resin.

[Conventional technology]

BACKGROUND OF THE INVENTION Synthetic resin bottles are becoming widely used as bottle-shaped containers for storing liquids such as whiskey and soy sauce.

The most effective method for forming this bottle is considered to be a method in which a primary molded product made of a crystalline synthetic resin material is formed into a bottle by biaxial stretch blow molding, and in particular, molded from polyethylene terephthalate resin. The resulting biaxially stretched blow-molded bottle had many advantages, including being thin and lightweight, having excellent mechanical strength and resistance to contents, and being able to be mass-produced at low cost.

By the way, the liquid stored in this type of bottle is often heated and filled, so as it cools down after being stored, the inside of the bottle becomes negative pressure, and the bottle, especially the body part, deforms under reduced pressure. There is a problem with the appearance that makes it unsightly.
In order to solve this problem, it has been attempted to provide a plurality of vertically elongated flat surface portions on the body of the bottle.

[Problem that the invention attempts to solve]

In this way, the body of the bottle is provided with a plurality of vertically long flat surface portions arranged in parallel in the circumferential direction.
When negative pressure is generated within the bottle due to reduced pressure, the easily deformable flat surface portion collapses inward to absorb the reduced pressure and prevent the entire body of the bottle from deforming unevenly.

During the decompression absorption deformation in which the flat surface portions collapse inward, the cylindrical wall portion located between the flat surface portions also curves slightly inward over its entire height range as the flat surface portions deform. At this time, the cylindrical wall portion is deformed into a shape in which the planar cross-sectional shape of the cylindrical wall portion protrudes outward due to the action of deformation stress on the flat surface portion.

When the cylindrical wall portion deforms into a flat cross-sectional shape in which the center part protrudes outward, it functions like a vertical rib, and as a result, it exerts a strong opposing force against the force that tends to deform inwardly. will be able to demonstrate this.

Therefore, if the degree of depressurization that occurs inside the bottle is large and the force that tends to cause the bottle to collapse and deform inward becomes stronger than the drag force of the cylindrical wall portion that functions like a vertical rib, this cylindrical wall portion will It undergoes inverted bending deformation approximately at the center in the height direction.

This reverse bending deformation caused by the cylinder wall is a local deformation, so if this deformation occurs, not only will the appearance of the bottle be severely damaged, but it will also permanently deform without reversing even after the negative pressure is released. Further, due to the bending deformation, cloudiness occurs in the bent portion, degrading the appearance of the bottle.

Moreover, since this type of bottle is handled as a product with negative pressure generated inside the bottle, manual gripping force is applied to the body during handling. There was a serious problem in that this action caused permanent deformation of the cylinder wall portion due to reverse bending deformation.

The present invention was devised to solve the problems, drawbacks, and inconveniences of the conventional examples described above.
The purpose is to ensure the mechanical strength of the cylindrical wall portion between the flat surface portions formed on the body, and to prevent deterioration of the external appearance due to deformation under reduced pressure.

[Means for solving problems]

Hereinafter, the present invention will be explained with reference to the drawings showing one embodiment of the present invention.

The biaxially stretched blow-molded bottle 1 according to the present invention has a cylindrical body 2 with a plurality of longitudinal flat surface portions 4 formed in parallel at regular intervals on the wall of the body 2 for absorbing reduced pressure. A plurality of horizontal ribs 5 are provided at intervals in the vertical direction on the above-mentioned cylindrical wall portion between the flat surface portions 4.

This horizontal rib 5 prevents the cylindrical wall portion from unnecessarily deforming into a flat cross-sectional shape with its central portion protruding outward as the flat surface portion 4 deforms due to the negative pressure generated within the bottle body 1. Therefore, it is formed with sufficient mechanical strength to resist the deformation stress acting from the flat surface portion 4 deformed to absorb reduced pressure.

[Effect]

Since the present invention has the above-described configuration, when negative pressure is generated within the bottle 1, the flat surface portion 4 provided on the body 2 that is easily elastically deformed is deformed inwardly with a large radius of curvature. Then, the reduced pressure inside the bottle 1 due to the negative pressure is absorbed.

Along with this decompression deformation of the flat surface portions 4, the cylindrical wall portion of the body 2 located between the flat surface portions 4 also deforms.
is depressed and curved with a large radius of curvature along the height direction, but at this time, due to the reinforcing action of the horizontal ribs 5, the flat cross-sectional shape of the cylinder wall portion along the circumferential direction becomes a curved shape that protrudes outward. Maintains a flat cross-sectional shape.

Therefore, even if the degree of negative pressure generated within the bottle body 1 becomes unexpectedly large, the overall degree of curved deformation along the height direction of the cylinder wall portion will only increase, and this cylinder wall portion No reverse bending deformation occurs at all.

In other words, the cylindrical wall portion between the flat surface portions 4 is a portion that is much less susceptible to curve deformation due to reduced pressure than the flat surface portion 4, but by providing the horizontal ribs 5, a large deformation force is applied. In this case, it becomes possible to deform elastically without resisting this deformation force.

Therefore, the horizontal ribs 5 have the function of expanding the range of elastic deformation of the cylinder wall portion between the flat surface portions 4 in the direction of deformation to absorb and absorb the reduced pressure.

Due to the shape of the horizontal ribs 5, the cylindrical wall portion between the flat surface portions 4 is likely to undergo elastic deformation along the height direction in accordance with the elastic deformation of the flat surface portions 4 to absorb deformation under reduced pressure. However, on the other hand, deformation along the circumferential direction is difficult, and therefore no reverse bending deformation occurs.

Further, the cylindrical wall portion between the flat surface portions 4 is a portion that comes into contact with the palm of the hand when gripping the bottle 1 with one hand, and a large number of horizontal ribs 5 are formed on the surface of this cylindrical wall portion. Therefore, the horizontal ribs 5 effectively act as anti-slip, which makes it easier to handle the bottle 1 with one hand.
Handling safety can be improved.

〔Example〕

In the illustrated embodiment, the bottle 1 has a substantially cylindrical body 2, and a circumferential groove 3 is provided around the body 2 at a slightly upper portion thereof.

Further, the flat surface portions 4 are arranged in parallel at regular intervals in the vertical direction at intervals below the circumferential groove 3, and the plurality of horizontal ribs 5 are arranged in parallel with each other at regular intervals in the vertical direction, and the total height of the cylindrical wall portion between the flat surface portions 4 is It is formed over a wide range of areas.

By providing the horizontal ribs 5 in this manner, the cylindrical wall portion can be curved almost uniformly over its entire height range, and the deformation is less likely to be seen as an unsightly appearance.

[Effect of idea]

As is clear from the above explanation, 2
Even if deformation occurs due to negative pressure as the heated stored liquid cools, the axially stretched blow-molded bottle uniformly and reliably absorbs this deformation, and thus It is possible to prevent deterioration of the appearance due to deformation, ensure mechanical strength, have a simple structure and easy molding, and furthermore, the horizontal ribs function as a non-slip so that the bottle can be handled with one hand. It exhibits many excellent effects, such as making it easier.

[Brief explanation of drawings]

FIG. 1 is a front view of a biaxially stretched blow-molded bottle according to the present invention. FIG. 2 is a sectional view of the main part. Explanation of symbols: 1; Bottle; 2; Body; 3; Circumferential groove;
4; flat surface portion; 5; horizontal ribs.

Claims (1)

[Scope of utility model registration request] A plurality of vertically elongated flat surface portions that absorb reduced pressure are formed in parallel at regular intervals on the cylindrical wall of the cylindrical body, and a plurality of horizontal ribs are vertically formed on the cylindrical wall portion between the flat surface portions. 2 provided at intervals in the direction
Axial stretch blow molded bottle.