JPH0711516U - Plastic bottle - Google Patents

Abstract

(57) [Summary] [Purpose] To obtain a reinforcing rib structure for improving the strength of the panel wall portion, and to obtain a thin bottle in which the panel wall can be surely restored even when filled under a slight pressure. [Structure] An endless continuous rectangular groove 4 is formed in a panel wall 2, an endless ridge 5 is further formed inside the endless groove 4, and an inner surface surrounded by the endless ridge is a panel. The stepped surface 6 is slightly recessed from the wall surface, and the stepped surface 6 is formed with a vertical groove 7 and two lateral grooves 8 and 9 orthogonal to the vertical groove 7.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic bottle, and more particularly to a reinforcing rib structure formed on a panel wall portion of a bottle body to improve its strength.

[0002]

[Prior art]

 In recent years, PET bottles and other plastic bottles are required to be thinner in order to save resources and reduce material costs. By forming reinforcing ribs on the panel wall to improve strength, the thinness of the body can be reduced. It is trying to make it. Therefore, a rib structure that can more effectively improve the strength of the panel wall is required. Conventionally, for example, Japanese Utility Model Publication No. 62-1061, Japanese Utility Model Publication No. 1-164128, and Japanese Utility Model Publication No. 2-10 2316 are required. Ribs with various structures have been proposed, as shown in Japanese Patent Laid-Open Publication No. Hei 10-31100 and FIG. Thus, by effectively forming the reinforcing ribs on the wall of the bottle panel, the buckling strength and pressure resistance of the plastic bottle are further improved, and the wall thickness of the bottle has been relatively reduced. .

On the other hand, on the other hand, the filling speed is required to be high, filling is performed under slight pressure, and the bottle is required to have higher strength than it can withstand. For example, if a thin-walled plastic bottle is hot-packed with a content liquid requiring sterilization under slight pressure, the panel wall of the bottle expands considerably during filling. In the case of conventional bottles with a wall thickness of 0.4 mm or more, there was no problem with this expansion during filling because the bottle can be restored to its original state by cooling after filling, but the above requirements are satisfied. Therefore, in the case of a bottle whose wall thickness is thinned to 0.37 mm to 0.38 mm, the bottle with the conventionally known reinforcing rib cannot be completely restored even after cooling, and the bulge remains. become. Bottles with a slightly inflated panel wall had the problem that the label panel-attached body panel wall rubbed during the distribution process, damaging the label and reducing the commercial value.

[0004]

[Problems to be solved by the device]

 The present invention was devised in order to solve the problems of the conventional plastic bottles described above, and found a reinforcing rib structure that can further improve the strength of the panel wall of the bottle. It is an object of the present invention to provide a plastic bottle that can reliably restore the panel wall after hot pack filling even under a slight pressure, thereby further reducing the thickness of the body. .

[0005]

[Means for Solving the Problems]

 In order to obtain a rib structure that is most effective in improving the strength of the bottle, the present inventor made various trials of plastic bottles with different rib structures and, as a result of repeated experiments, the vertical screen and vertical groove on the partition screen defined by the endless groove. The present inventors have found that the composite rib structure in which a lateral groove that is orthogonal to the vertical groove is formed, so that the restoring force of the panel wall portion is dramatically improved as compared with the conventional rib structure. It was done.

That is, the plastic bottle of the present invention has an endless groove continuously formed in the panel wall portion of the body portion, a vertical groove formed in the section screen surrounded by the endless groove, and The above problem has been solved by a configuration characterized by having a composite rib composed of a lateral groove orthogonal to the vertical groove.

The partition screen is an endless convex strip whose top formed inside the endless groove reaches substantially the height of the panel wall surface, and a step surface surrounded by the endless convex strip and slightly recessed from the panel wall surface. It is preferable that the vertical groove and the horizontal groove are formed on the step surface, and it is more preferable that the number of the horizontal groove is two or more. The composite rib does not have to be provided on both the upper panel wall portion and the lower panel wall portion, and may be provided on only one of them, but if it is provided on both, the strength is further improved.

[0008]

[Action]

 By forming the reinforcing ribs on the panel wall of the bottle body, the strength of the panel wall is improved and the restoring force after swelling is improved. Experiments have shown that by using a composite rib structure in which a vertical groove and a horizontal groove orthogonal to the vertical groove are formed on the screen divided by the endless groove, the restoring force is significantly improved compared with the conventional rib structure. found. According to the embodiment of the second aspect of the present invention, in the hot pack under slight pressure, the conventional rib structure is a thin-walled bottle having a wall thickness of 0.37 mm to 0.38 mm in which the bulge of the panel remains after cooling. It was confirmed that it could be completely restored. Therefore, even if it is a thin bottle, the bulge of the body does not remain, and the problem that the label provided on the panel wall is rubbed during the product distribution stage and the product value is reduced can be solved. . Further, providing the rib structure on both the upper panel wall portion and the lower panel wall portion improves the strength.

[0009]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a plastic bottle according to the present invention, and an AA sectional view thereof is shown in FIG. The plastic bottle 1 of the present embodiment is a bottle in which the composite rib structure of the present invention is applied only to the upper portion of each panel wall portion 2 of the body having a square shape with a square cross section.

In the figure, 3 is a composite rib according to the present embodiment, in which an endless continuous rectangular groove 4 is formed in the panel wall portion 2, and the inner peripheral wall of the endless groove 4 is almost the same as the panel wall surface. The endless ridge 5 is formed by rising to the height and then descending, and the inner surface surrounded by the endless ridge 5 is a step surface 6 slightly depressed from the panel wall surface, and the step surface 6 has a vertical groove. 7 and two lateral grooves 8 and 9 orthogonal to the vertical groove 7 are formed. In addition, 10 is a reinforcing rib formed on the lower panel wall portion, and 11, 12 and 13 are lateral ribs, respectively, and these ribs have the same structure as the conventional one.

With respect to the plastic bottle of the present embodiment configured as described above and the conventional plastic bottles shown in FIGS. 6 and 7, the panel wall is restored for five bottles each by the following method. A comparative test of the degree was performed. In the conventional plastic bottle 32 shown in FIGS. 6 and 7, a large rectangular endless groove 33 is formed in the panel wall portion, and a partition screen defined by the endless groove is substantially level with the panel wall surface. Endless stepped surfaces 35 and 36 are sequentially formed by recessing from the endless top surface 34 of the endless groove 34, and one longitudinal groove 37 having substantially the same depth as the endless groove is formed at the center to form a composite rib. ing.

Comparative Test 1. Target Bottle The plastic bottles of the present example and the conventional example are the same except that the form of the composite rib on the upper part of the panel wall is different, and both are bottles of biaxially stretched polyester resin having a weight of 48 g. 2. Experimental method Measure the barrel diameter of the upper panel wall with an empty bottle. Fill with hot water of 85 ℃ and measure the diameter of the cylinder at the same place as when counter pressure of 0.30kg / cm ² was applied. In this state, hold for 5 seconds and then measure the diameter of the cylinder when the counter pressure is released. Then, the body diameter is measured after soaking in water at room temperature (20 to 25 ° C.) and cooling. The above results are shown in FIG. FIG. 3 shows the average values of the barrel diameters of the panel wall portion measured in each of the above 5 to 5 for the example and the conventional example, and the line a is the barrel of the plastic bottle of the example. This is the change in diameter, and line b shows the change in barrel diameter of the conventional plastic bottle.

As is clear from the figure, the barrel diameter under the counter pressure is about the same as that of the plastic bottles of the present embodiment and the conventional example, but after cooling, it is empty in the present embodiment. In contrast, in the case of the conventional example, the body diameter is about 2.5 mm larger than in the empty state, and it can be seen that bulges remain and it is not possible to recover. Therefore, from these results, it was confirmed that the composite rib of the present invention is extremely effective in restoring the panel wall portion.

4 and 5 show a plastic bottle according to another embodiment of the present invention. Also in the plastic bottle 21 of this embodiment, the composite rib 23 having the structure according to the present invention is formed only on the upper panel wall portion 22 similarly to the above-mentioned embodiment. In the structure of the composite rib 23 in this embodiment, the upper side thereof is curved as a whole according to the shape of the bottle, and the outer endless groove 24 is formed in the lateral rib 30 in the middle portion and the lower panel wall portion. It is basically the same as the embodiment shown in FIGS. 1 and 2 except that it is continuous with the endless groove 32 of the formed composite rib 31, and therefore detailed description thereof will be omitted. In the figure, 24 is an endless groove, 25 is an endless ridge, 26 is a step surface, 27 is a vertical groove, and 28 and 29 are horizontal grooves.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various design changes can be made. For example, in the above-described embodiment, two lateral grooves are formed, but two or more lateral grooves, for example three, may be formed, or in some cases, only one lateral groove may be formed. In addition, in each of the above embodiments, the composite rib according to the present invention is formed only on the upper panel wall portion, but it is of course possible to form the composite rib on both the lower panel wall portion or only the lower panel wall portion. It is appropriately determined according to the shape and bottle thickness.

[0016]

[Effect of device]

 As described above, according to the plastic bottle of the present invention, the strength is significantly increased as compared with the conventional rib structure, and the restoring force of the panel wall portion is dramatically improved. Therefore, even if the conventional rib structure in the hot pack under slight pressure still bulges the panel wall after cooling, the rib structure of the present invention can be used to completely restore the panel wall. Therefore, it is possible to prevent a decrease in commercial value. Further, it is possible to further reduce the thickness of the body portion and reduce the material cost.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along the line AA.

FIG. 3 is a graph showing changes in the body diameter of the panel wall during hot pack filling under slight pressure.

FIG. 4 is a front view of a plastic bottle according to another embodiment of the present invention.

FIG. 5 is a BB sectional view thereof.

FIG. 6 is a front view of a conventional plastic bottle.

FIG. 7 is a sectional view taken along the line CC.

[Explanation of symbols]

1, 21 Plastic bottle 2, 22 Panel wall part 3, 23 Composite rib 4, 24 Endless groove 5, 25 Endless convex strip 6, 26 Step surface 7, 27 Vertical groove 8, 9, 28,
29 Yokomizo

Claims (4)

[Scope of utility model registration request] 1. An endless groove which is continuously formed in an endless shape on a panel wall portion of a body, a vertical groove which is formed in a screen surrounded by the endless groove, and a lateral groove which is orthogonal to the vertical groove. A plastic bottle having a composite rib composed of 2. The end surface of the partition screen is formed so that the top portion formed inside the endless groove reaches substantially the height of the panel wall surface, and a step surrounded by the endless projection line and slightly recessed from the panel wall surface. The plastic bottle according to claim 1, wherein the vertical groove and the horizontal groove are formed on the step surface. 3. The plastic bottle according to claim 1, wherein the number of the lateral grooves is two or more. 4. The composite rib is formed on the upper panel wall and the lower panel wall of the body.
The listed plastic bottle.