JPS6311212B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a thin walled saturated polyester resin bottle suitable for filling carbonated beverages, soft drinks, etc. The object of the present invention is to provide a saturated polyester resin bottle that exhibits excellent properties in terms of strength and standing stability.

[Conventional technology]

For example, carbonated beverages, soft drinks, etc. have traditionally been filled in glass bottles, but glass bottles with internal pressure resistance are relatively thick, resulting in heavy weight and transportation costs. It was not satisfactory in terms of portability, etc.

Therefore, as a container that eliminates the disadvantages of the glass bottle, there is a bottle made of synthetic resin with a thin inner surface made by biaxial stretching, which has a cylindrical body and a spherical bottom that projects downward as a whole, and a cylindrical bottle with a thinner inner surface. A biaxially stretched thin synthetic resin bottle has been proposed, which has a body and a bottom having a plurality of legs that bulge downward at the peripheral edge of the bottom wall.

[Problem that the invention seeks to solve]

By the way, with the thin synthetic resin bottle made of biaxially stretched material having a spherical bottom projecting downward, the grounding part of the bottle becomes spherical, making it impossible to stand the bottle in a stable state. It is necessary to secure the standing stability of the bottle by inserting a hakama-shaped foot stand made of plastic, which not only increases cost but also makes the appearance unsightly, and furthermore, the position of the foot stand may shift. If the fitting is incomplete, the bottle in the upright position will tilt, causing the filling nozzle to shift from the bottle opening during automatic filling of the liquid filling.
There are drawbacks such as poor filling.

In addition, a biaxially stretched thin synthetic resin bottle that has a plurality of legs that bulge downward on the other bottom wall periphery has the disadvantage that the bottom end of the leg, which is the ground contact part of the bottle, tends to become thinner. In addition, since the tip of the plurality of legs serves as a ground-contacting part, there are drawbacks such as the fact that there are cases where the bottle cannot be stood up in a stable upright state.

On the other hand, the thin-walled saturated polyester resin bottle of the present invention has a particularly reinforced bottom including the ground-contacting part, and not only has an excellent effect on internal pressure resistance, but also has an excellent effect on achieving standing stability. It is possible to obtain a stable standing state without attaching a footrest, etc., and it has a good appearance and has excellent transport and storage characteristics, and is easy to mold. It also has the ease of use.

[Means for solving problems]

The thin-walled bottle made of saturated polyester resin of the present invention comprises: a neck portion having an open rim at the upper end; a shoulder portion continuous to the neck portion; a body portion having a circular cross section continuous to the shoulder portion; This is a thin-walled bottle made of saturated polyester resin, consisting of a bottom portion that closes the lower open end of the body portion, and at least the portion other than the mouth and neck portion is biaxially stretched. In the thin-walled bottle made of saturated polyester resin of the present invention, which is constituted by the mouth and neck, shoulders, body, and bottom, the bottom has a cap-shaped portion with a central portion protruding inward of the bottle. Moreover, the inner peripheral surface of the bottle is provided with a plurality of solid protruding ribs that project radially from the upper end of the cap-shaped part to the lower part of the body of the bottle. .

〔Example〕

Hereinafter, the specific structure of the thin-walled saturated polyester resin bottle of the present invention will be explained based on drawing examples.

A thin-walled saturated polyester resin bottle, which is an embodiment of the present invention and is designated by reference numeral 1 in FIG. It consists of a shoulder part 3, a neck part 5 whose outer peripheral surface is a threaded part 4 and whose upper end is an open mouth edge part, and a bottom part 6 that closes the lower open end of the body part 2.

The bottom portion 6 of the thin-walled bottle 1 made of saturated polyester resin has a cap-shaped portion 7 whose central portion protrudes inward.
Furthermore, the inner peripheral surface of the bottle 1 has a plurality of solid protrusions extending from the upper end of the cap-shaped part 7 to the lower part of the body part 2, as shown in FIG. Ribs 8, 8, 8, . be.

The thin-walled bottle 1 made of saturated polyester resin shown in the drawing embodiment having the above-mentioned configuration is, for example, a third
This can be easily obtained by biaxially stretch blow molding an intermediate material 11 made of saturated polyester resin having the shape shown in the figure in a blow mold. That is, as shown in FIG. 3, the inner periphery of the bottle 1 is attached to the inner periphery of a bottomed tubular body having a neck 12 having the same structure as the neck 5 of the thin-walled saturated polyester resin bottle 1 described above. Protrusions 15, 15, 1 to become ribs 8, 8, 8 on the surface
5. Intermediate material 11 having a structure comprising...
is heated to the stretching temperature of the intermediate material 11, and then biaxially stretched and blow-molded in a blow-molding mold in which the center of the inner circumferential surface of the bottom part is a cap-shaped part that protrudes upward. This is what you get.
Incidentally, the threaded portion 13 that is attached to the intermediate material 11 has the same structure as the threaded portion 4 formed on the outer peripheral surface of the mouth and neck portion 2 of the thin-walled bottle 1 made of saturated polyester resin described above. Further, a method of biaxially stretching blow molding the intermediate material 11 within a blow molding mold is, for example, biaxially stretching blow molding an intermediate material molded by injection molding or the like. A general molding method is used to obtain a synthetic resin bottle by using the intermediate material 11.
By biaxial stretch blow molding, in which compressed air is blown into the inside of the mold and at the same time the bottom inner surface of the intermediate material 11 is pressed down using a push-down rod, etc., an outer shell that matches the shape of the inner circumferential surface of the blow molding mold is formed. This is a thin-walled bottle 1 made of saturated polyester resin.

[Operation and effect of the invention]

The thin-walled saturated polyester resin bottle of the present invention is biaxially stretched at least in parts other than the mouth and neck, and the center part of the bottom that closes the lower open end of the bottle body extends inward. The bottle has a protruding cap-shaped portion, and the inner peripheral surface of the bottle is provided with a plurality of solid protruding ribs that protrude radially from the upper end of the cap-shaped portion to the lower part of the bottle body. It is equipped with the following.

Therefore, the thin-walled bottle made of saturated polyester resin of the present invention has extremely high internal pressure resistance due to the synergistic effect of the cap-shaped portion at the bottom of the bottle and the solid protruding ribs protruding from the inner peripheral surface of the bottle. It not only has excellent functions and effects, but also has excellent rigidity.

Further, in the thin-walled bottle made of saturated polyester resin of the present invention, since the center part of the bottom of the bottle is a cap-shaped part that protrudes inward, the annular part surrounding the cap-shaped part serves as the grounding part of the bottle. This is the result. Therefore, excellent standing stability can be achieved without the need for attaching a footrest or the like in order to obtain stability in standing up of the bottle. In particular, the upright stability of the thin-walled bottle made of saturated polyester resin of the present invention is achieved by providing a continuous ring-shaped grounding part surrounding the cap-shaped part at the center of the bottom, and is extremely excellent. Therefore, even when placing the bottle on an automatic filling line and injecting the liquid filler, there is a risk of "misalignment" between the bottle opening and the filling nozzle due to the bottle's upright stability.
Filling defects caused by this can be avoided, and stable automatic filling can be performed.

Further, in the thin-walled bottle made of saturated polyester resin of the present invention, the bottle is reinforced by a cap-shaped portion at the center of the bottom of the bottle that projects inward and a solid protruding rib that projects from the inner peripheral surface of the bottle. This is achieved in combination with biaxial stretching applied to at least the parts other than the mouth and neck, so the outer circumferential surface of the bottle is smooth, the appearance is orderly and the appearance is good, and the transport properties are good. It also has good storage characteristics.

Furthermore, since the thin-walled bottle made of saturated polyester resin of the present invention uses saturated polyester resin as the raw material for the bottle, it is hygienic as there is no leakage of harmful substances such as solvents, and it can be disposed of or incinerated after use. In this case, no harmful gases are generated, and it has an excellent effect in terms of environmental protection.

In addition, the thin-walled bottle made of saturated polyester resin of the present invention has a structure in which the intermediate material is made of a bottomed tubular body made of saturated polyester resin and has a plurality of protrusions on the inner circumferential surface. Since it is obtained by a manufacturing method that involves biaxial stretch blow molding in a blow molding mold that has a cap-shaped part that projects upward, it also has the advantage of being easy to mold. be.

[Brief explanation of the drawing]

FIG. 1 is a side view showing a part of a thin-walled bottle made of saturated polyester resin, which is an example of the present invention;
Figure 2 is a sectional view taken along the - line in Figure 1, and Figure 3 is a cross-sectional view of Figure 1.
FIG. 2 is a sectional view of an intermediate material used to obtain the thin-walled saturated polyester resin bottle shown in the figure. 1: Thin-walled bottle made of saturated polyester resin, 2: Body, 3: Shoulder, 5: Mouth and neck, 6: Bottom, 7: Cap-shaped portion, 8: Solid protruding rib.

Claims (1)

[Claims] 1. A mouth and neck part whose upper end is an open mouth edge, a shoulder part continuous to the mouth and neck part, a body part with a circular cross section continuous to the shoulder part, and a lower open end of the body part closed. A thin-walled bottle made of saturated polyester resin comprising a bottom portion, at least a portion other than the mouth and neck portion is biaxially stretched, and the bottom portion has a cap-shaped portion whose center portion protrudes inwardly of the bottle; Moreover, the bottle is made of saturated polyester resin and has a plurality of solid protruding ribs extending radially from the upper end of the cap-shaped part to the lower part of the body of the bottle on the inner peripheral surface of the bottle. Thin bottle.