JPH0659207U - Biaxially stretched polyethylene terephthalate bottle - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a bottle made of biaxially stretched polyethylene terephthalate which has a small deformation under reduced pressure and a high buckling strength without increasing the material cost. [Structure] A biaxially stretched polyethylene terephthalate bottle 1 is inclined at an angle in the range of 31.5 ° to 38.5 ° with respect to the axis y of the bottle 1 around at least the lower half 3b of the body 3. A plurality of inclined groove portions 6 are provided at intervals. [Effect] The inclination angle of the inclined groove portion is 31.5 ° to 38.
When the angle is in the range of 5 °, the reduced pressure deformation due to the hot pack is small, and extremely high buckling strength can be obtained without increasing the wall thickness of the bottle.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an improvement in a biaxially stretched polyethylene terephthalate bottle for containing liquid contents such as seasonings and oils.

[0002]

[Prior art]

 Conventionally, bottles made of biaxially stretched polyethylene terephthalate as disclosed in Japanese Utility Model Publication No. 61-107711 are known.

As shown in FIG. 3, this type of bottle 30 is composed of a mouth portion 31, a body portion 32, and a bottom portion 33, and after filling the inside of the bottle 30 with a liquid content, A cap (not shown) is attached to the portion 31 to seal it.

Further, a plurality of horizontal recessed portions 34 are horizontally formed on the upper half portion 32a of the body portion 32 at intervals along the entire circumference thereof, and are formed in the central portion 32b of the body portion 32. Is formed with a constricted portion 35 having a deeper groove shape than the horizontal recessed portion 34. Further, the lower half portion 32c of the body portion 32 is formed with a plurality of inclined groove portions 36 which are inclined at an angle of 30 ° with respect to the axis y of the bottle 30 at the entire circumference thereof. ing.

By the way, since the bottle 30 is excellent in strength, transparency and gas barrier property and is comparatively light in weight, it has been used as a container for carbonated drinks or the like. It is also used as a so-called hot pack container for filling contents such as oils in a state of being heated to around 70 ° C.

The bottle 30 having the above structure is suitable as a container for hot packs. That is, the internal pressure of the bottle 30 decreases due to the decrease in the temperature of the contents sealed in the bottle 30. At this time, each of the inclined groove portions 36 promotes uniform torsional deformation of the lower half portion 32c of the body portion 32, reduces the volume of the bottle 30, and absorbs the decrease in the internal pressure of the bottle 30. As a result, even if the contents hermetically sealed inside the bottle 30 contract due to a decrease in temperature, the inclined concave streaks 36 uniformly absorb the decrease in internal pressure and relatively reduce the pressure reduction deformation of the bottle 30. It is possible to prevent the bottle 30 from being deformed to a large extent and spoiling its aesthetic appearance by making it small.

However, while the bottle 30 is suitable as a container for hot packs, the inclined groove portions 36 are easily deformed by the vertical load applied to the bottle 30, and the lower half portion 32c of the body portion 32 is easily deformed. However, the buckling strength is low.

Therefore, it is conceivable to increase the thickness of the bottle 30 to increase the buckling strength of the inclined groove portions 36. However, in order to form the bottle 30 having a relatively large thickness, There is a disadvantage that the material cost of the material, polyethylene terephthalate, increases.

[0009]

[Problems to be solved by the device]

 An object of the present invention is to provide a bottle made of biaxially stretched polyethylene terephthalate, which eliminates such inconvenience, reduces deformation under reduced pressure, and has high buckling strength without increasing material cost.

[0010]

[Means for Solving the Problems]

 The present inventor has examined the inclination angles of a plurality of concave streak portions formed around the entire circumference of the body of the bottle with respect to the bottle axis line, and as a result, the concave streak portion is less than 31.5 ° with respect to the bottle axis line. When tilted at an angle, the deformation due to decompression inside the bottle is small, but the buckling strength is reduced, and the groove is tilted at an angle of more than 38.5 ° with respect to the axis of the bottle. On the other hand, it was found that while the buckling strength is improved, the deformation inside the bottle due to the pressure reduction is large.

Therefore, in order to achieve the above-mentioned object, the present invention provides a biaxially stretched polyethylene terephthalate bottle comprising a mouth, a body, and a bottom, at least on the entire circumference of the lower half of the body. The present invention is characterized in that a plurality of inclined groove portions that incline at an angle of 31.5 ° to 38.5 ° with respect to the axis of the bottle are formed at intervals.

[0012]

[Action]

 According to the bottle of the present invention, a plurality of groove portions are formed at intervals around at least the lower half portion of the body portion, and the groove portions are formed at 31.degree. With respect to the axis of the bottle. Since it was formed by inclining at an angle in the range of 5 ° to 38.5 °, the deformation due to the reduced pressure inside the bottle is small and the buckling strength is high.

[0013]

【Example】

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a side view showing a biaxially stretched polyethylene terephthalate bottle of the present embodiment (hereinafter simply referred to as PET bottle), and FIG. 2 is a sectional view taken along line II-II of FIG.

The PET bottle 1 of the present embodiment is formed by stretch blow molding of a polyethylene terephthalate material and is biaxially oriented. As shown in FIG. 1, the PET bottle 1 includes a mouth portion 2, a body portion 3 and a bottom portion 4. It is configured. The PET bottle 1 has a volume capable of accommodating 1 liter of liquid content and has a height dimension of about 256 mm. Further, the PET bottle 1 has a comparatively light weight of 33 g, so that the body portion 3 has a relatively thin wall thickness of 0.28 to 0.30 mm.

On the upper half portion 3a of the body portion 3, four horizontal groove-like horizontal groove portions 5 are formed horizontally in the vertical direction at equal intervals in the vertical direction. The horizontal recessed portion 5 is formed with a depth of about 1.45 mm and a width of about 8.3 mm, respectively.

Further, in the lower half portion 3b of the body portion 3, eight inclined groove portions 6 extending in a circumferential direction and extending in the circumferential direction are formed at equal intervals. Each inclined groove portion 6 is formed to be inclined at an angle of 35 ° with respect to the axis y of the PET bottle 1. The height dimension of the lower half portion 3b of the body portion 3 is formed to be about 115.5 mm, and the inclined groove portion 6 extends over about 89.5 mm within the height dimension of the lower half portion 3b. It has a width of about 22 mm and a depth of about 3.5 mm.

Further, a constricted portion 7 is formed in the central portion 3c of the body portion 3, and the constricted portion 7 has a depth dimension of about 4.5 mm and a width dimension of about 25 mm. There is.

A cap (not shown) can be attached to the mouth portion 2 when the inside of the PET bottle 1 is filled with a liquid content, and the cap allows the liquid to be put inside the PET bottle 1. The contents are sealed.

Next, the operation when the PET bottle 1 having the above-mentioned configuration is filled with a liquid content by a hot pack and hermetically sealed will be described.

The liquid content sealed inside the PET bottle 1 is usually heated to around 70 ° C. and filled, so that the PET bottle 1 is cooled in a sealed state. As a result, the pressure inside the PET bottle 1 decreases as the temperature of the liquid contents decreases. When the inside of the PET bottle 1 is depressurized, the volume of the PET bottle 1 is reduced and the body 3 of the PET bottle 1 is pulled inward. At this time, as shown in FIG. 1 and FIG. 2, since the PET bottle 1 has the inclined groove portion 6 formed in the lower half portion 3b thereof, the inclined groove portion 6 is located below the body portion 3. A uniform twisting deformation is promoted over the entire circumference of the half portion 3b, and the lower half portion 3b is reduced in diameter as shown by an imaginary line in an exaggerated manner in FIG. 2, and the volume reduction amount of the PET bottle 1 is absorbed. Thereby, the deformation of the lower half portion 3b does not affect the upper half portion 3a, and it is possible to prevent the appearance of the entire PET bottle 1 from being largely deformed.

Here, the present inventor conducted a comparative test on the conventional PET bottle 30 (shown in FIG. 3), the PET bottle 1 of the present embodiment (shown in FIG. 1) and the PET bottle for test (not shown). .

In the conventional PET bottle 30, as described in the section of the prior art, the inclined recessed portion 36 is inclined at an angle of 30 ° with respect to the axis y of the bottle 30, and the above-mentioned test is performed. The PET bottle for use has an inclined concave portion inclined at an angle of 40 ° with respect to the axis of the bottle. The portions other than the inclined recessed portions 36 of the conventional PET bottle 30 and the test PET bottle are formed similarly to the PET bottle 1 of this embodiment.

It should be noted that the PET bottle 1 of the present embodiment is similar to the conventional PET bottle 30 in that the body portion 3 has a relatively thin weight of 33 g. In order to clarify the above, not only those having a basis weight of 33 g but also those having a basis weight of 36 g in which the thickness of the body portion 3 is made relatively thick are used. Similarly, in the case of the conventional PET bottle 30 and the PET bottle for test, A product having a basis weight of 36 g was used.

In this comparative test, the above PET bottles 1 and 30 were filled with liquid contents and sealed, and a vertical load was applied to measure the crushing limit weight (kg) to measure the buckling strength. In both cases, the pressure reduction deformation was measured by measuring the change in the circumferential dimension of the lower half portions 3b and 32c of the body portions 3 and 32. That is, the buckling strength was measured for each of the PET bottles 1 and 30 filled with the liquid content at room temperature and with the liquid content heated to 72 ° C. When the product was filled, the measurement was carried out immediately after the filling and after being left to stand for 3 days and naturally cooled. The measurement of deformation under reduced pressure was performed after filling the liquid contents heated to 72 ° C., leaving it for 2 weeks, and further cooling to 5 ° C.

The results of this comparative test are shown in Table 1.

[0027]

[Table 1]

As shown in Table 1, the conventional PET bottle 30 in which the inclination angle of the inclined recessed portion 36 is 30 ° has a weight of 33 g, the pressure reduction deformation is relatively small at 2.26 mm, but the buckling The strength is extremely low, especially 25.5 kg immediately after filling at 72 ° C, and the PET bottle for testing with an inclined angle of the inclined groove of 40 ° has a buckling strength immediately after filling at 72 ° C with a unit weight of 33 g. Even if there is 36.9 kg, it is extremely high, but the reduced pressure deformation is 9. Very large at 56 mm. As described above, this comparative test revealed that the buckling strength is higher as the inclination angle of the inclined groove is larger, and the reduced pressure deformation is smaller as the inclination angle of the inclined groove is smaller.

Then, as shown in Table 1, in the PET bottle 1 of the present embodiment, even if the weight of the PET bottle 1 is 33 g, the inclination angle of each inclined groove portion 6 is set to 35 °. ℃ Immediately after filling, it is extremely high at 35.4 kg, and it is possible to obtain a much higher buckling strength than that of the conventional PET bottle 30 having a basis weight of 33 g, and also to increase the thickness of the conventional PET bottle 30. It is possible to obtain a higher buckling strength than that with a basis weight of 36 g. Moreover, the PET bottle 1 of the present embodiment having a basis weight of 33 g has a reduced pressure deformation of 3. It is 43 mm, and even if the reduced pressure deformation is larger than 2.26 mm of the conventional PET bottle 30, the difference is about 1.17 mm, which is extremely small, so it was clarified that it is suitable as a container for hot packs.

In this embodiment, the inclination angle of each inclined groove 6 of the PET bottle 1 is set to 35 °, but the inclination angle of each inclined groove 6 is 31.5 ° to 38.5 °. If the angle is within the range, the same effect as that of the PET bottle 1 of this embodiment can be obtained.

[0031]

[Effect of device]

 As is clear from the above, according to the present invention, a plurality of inclined ridges are formed at intervals around at least the lower half of the body, and the inclined ridges are formed in the bottle. By inclining at an angle in the range of 31.5 ° to 38.5 ° with respect to the axis of, the deformation due to the depressurization inside the bottle can be made small, for example, when filling and sealing the contents with a hot pack. In addition, the buckling strength can be dramatically improved without increasing the wall thickness.

Therefore, according to the present invention, since the wall thickness may be relatively thin, the biaxially stretched polyethylene terephthalate made of a biaxially stretched polyethylene terephthalate having a shape with a small deformation under reduced pressure and a high buckling strength without increasing the material cost. Bottles can be provided.

[Brief description of drawings]

FIG. 1 is a side view showing a biaxially stretched polyethylene terephthalate bottle according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a side view showing a conventional bottle made of biaxially stretched polyethylene terephthalate.

[Explanation of symbols]

1 ... Biaxially oriented polyethylene terephthalate bottle, 2
... mouth part, 3 ... body part, 3b ... lower half part, 4 ... bottom part, 6 ... inclined groove part, y ... axis line.

Claims (1)

[Scope of utility model registration request] 1. A biaxially stretched polyethylene terephthalate bottle consisting of a mouth, a body and a bottom, wherein at least the lower half of the body has a circumference of 3 with respect to the axis of the bottle.
A bottle made of biaxially stretched polyethylene terephthalate, characterized in that a plurality of inclined groove portions inclined at an angle in the range of 1.5 ° to 38.5 ° are formed at intervals.