JPH0811888A - Base cup and its manufacture and bottle with base cup - Google Patents

Abstract

PURPOSE:To facilitate the recycling of bottles with base cups by making the base cups of PET. CONSTITUTION:A base cup 30 is produced in such a way that a polyethylene telephthalate sheet are thermally stretched and formed by using a female mold. The base cup 30 has a tubular shape with a bottom and consists of the bottom 31 and a sidewall 40. Ground contact faces 33 and a concave spherical part 36 of the bottom 31 are connected by raised walls 37 that are raised neatly perpendicularly to the ground contact faces 33. Recessed parts 37a and protruding parts 37b are provided on the raised walls 37 alternately in the circumferential direction. Recessed parts 41a and protruding parts 41b are provided on the upper part of the sidewall 40 alternately in the circumferential direction. The insides of the recessed parts 41b serve as liquid inlets 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base cup attached to the bottom of a bottle body having a hemispherical shell shape, a method for manufacturing the base cup, and a bottle container with the base cup.

[0002]

2. Description of the Related Art Polyethylene terephthalate (hereinafter referred to as P
2. Description of the Related Art There is a bottle container made of abbreviated as ET) in which the bottom of the bottle body has a hemispherical shell shape to improve pressure resistance. Since the bottom portion of the bottle body has a hemispherical shell shape, the bottle body is not self-supporting. Therefore, by joining the bottomed cylindrical base cup to the bottom portion of the bottle body, the bottle body is provided with self-supporting property.

Japanese Patent Publication No. 5-36310 also discloses a conventional bottle container of this type.

[0004]

However, in the conventional bottle container described above, while the bottle body is made of PET, the base cup is made of polyethylene (hereinafter referred to as P).
(Abbreviated as E)). Therefore, when the bottle container is melted and the resources are reused, it is necessary to separate the both before melting, but this is extremely difficult as a practical problem.

Although the base cup made of PE is manufactured by injection molding, the injection molding method has a limitation that the wall thickness can be reduced, resulting in a heavy weight. Here, if the base cup is also made of PET, it is convenient because the bottle body and the base cup can be dissolved and reused together without being separated. However, PET
Even if the base cup was manufactured by injection molding, the strength that could withstand use could not be obtained.

The present invention has been made in view of the above problems of the prior art, and is a base cup which is lightweight and has sufficient strength and is easy to recycle, a manufacturing method thereof, and a bottle with the base cup. The purpose is to provide a container.

[0007]

The present invention adopts the following means in order to solve the above problems. <Summary of the Invention> The present invention has a bottomed tubular shape including a bottom portion and a peripheral wall portion, and is a base cup that is attached to a bottom portion protruding in a hemispherical shell shape of a bottle main body and serves as a leg of the bottle main body. A base cup formed by stretching a sheet made of polyethylene terephthalate by thermoforming (corresponding to claim 1).

The present invention also provides a base cup characterized in that the base cup is heat-set (corresponding to claim 2). The bottom of the cup is provided with a concave spherical surface portion that abuts the bottom of the hemispherical shell of the bottle body, and a grounding portion that surrounds the outside of this concave spherical surface portion, and the outer edge of the concave spherical surface portion and the inner edge of the grounding portion are grounded. The base cup is characterized in that the base cups are connected by an annular standing wall portion that stands up at a right angle to the portions (corresponding to claim 3).

Further, according to the present invention, in the base cup, concave portions and convex portions which are uneven in the radial direction are alternately formed in the standing wall portion in the circumferential direction ( (Corresponding to claim 4). Here, the cross-sectional shape of the concave portion and the convex portion may be quadrangular or arc-shaped,
It may be a triangle.

Further, according to the present invention, in any one of the above base cups, a liquid which is dropped and supplied from above the bottle main body when attached to the bottle main body is provided on an upper surface of a peripheral wall portion of the base cup. A liquid inlet for guiding the liquid into the base cup is provided along the base cup, and a discharge port for discharging the liquid that has entered the base cup is provided at the bottom of the base cup. 5).

Further, according to the present invention, in the above-mentioned base cup, concave portions and convex portions which are uneven in the radial direction are alternately formed on the upper edge portion of the peripheral wall portion of the base cup in the circumferential direction. The base cup is characterized in that an edge serves as the liquid inlet (corresponding to claim 6). Here, the cross-sectional shape of the concave portion and the convex portion may be quadrangular, arcuate, or triangular.

It is also possible to form a hole in the upper portion of the peripheral wall portion of the base cup and use this hole as the liquid inlet.

Further, according to the present invention, a female die having a molding surface having substantially the same shape and size as the outer shape of the bottomed cylindrical base cup to be molded, and a plug capable of penetrating into the female die are used for heating. A softened polyethylene terephthalate sheet is pushed into the female mold with the plug, and the sheet is brought into close contact with the molding surface of the female mold to form a base cup having a desired shape. The method for producing a base cup is characterized in that the method comprises a step of sticking out and stretching with a female mold (corresponding to claim 7).

The term "protruding the sheet with the female die" refers only to the relative movement between the sheet and the female die. Not only when the female die is actually moved, but also with the female die fixed. It also includes the case of moving.

The timing of ejecting the sheet with the female mold may be before or after the sheet is stretched by the plug, or at the same time.

Further, the present invention is characterized by comprising a polyethylene terephthalate bottle body having a bottom portion projecting in a hemispherical shell shape, and any one of the base cups attached to the bottom portion of the bottle body. It is a bottle container (corresponding to claim 8).

<Applicability of the Present Invention> The present invention can be used in the field of containers for containing liquid food such as juice and carbonated drinks.

[0018]

[Action]

<Operation of the present invention> By making the base cup made of polyethylene terephthalate, which is the same material as the bottle body, it becomes easy to recycle the bottle container.

The heat setting improves the heat resistance of the base cup, which is convenient for heat sterilization treatment and dew condensation prevention heating treatment. When the standing wall portion of the base cup stands up at a right angle to the ground contact portion, the strength of the standing wall portion against buckling can be increased.

By providing the rising wall with the concave portion and the convex portion, the strength of the standing wall portion against buckling can be further increased. When the base cup is provided with a liquid inlet and a discharge port, when performing heat sterilization processing or dew condensation prevention warming processing, hot water etc. can be introduced into the bottom of the bottle body and then discharged, ensuring the bottom of the bottle body. It can be heated or heated.

When the base cup is manufactured by the thermoforming method, if a step of sticking out the heat-softened PET sheet by a female mold and stretching the base sheet is provided, it is possible to improve the draw ratio and increase the appropriate density, and thus the base cup It is possible to increase the strength, heat resistance and transparency.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings of FIGS. [Bottle Container with Base Cup] FIG. 3 is a partially cutaway front view of the bottle container 1 with a base cup. Bottle container 1
Comprises a bottle body 10, a cap 20 and a base cup 30.

The bottle body 10 is made of PET and is manufactured by a biaxial stretch blow molding method. Bottle body 1
The cap 20 is screwed onto the mouth tube portion 11 of No. 0. The bottle body 10 has a bottom 12 protruding in a hemispherical shell shape in order to improve pressure resistance. An annular hooking convex portion 14 is formed between the bottom portion 12 and the straight body portion 13.

[Base Cup] The base cup 30 is joined and fixed to the bottom portion 12 of the bottle body 10. FIG.
Is a vertical cross-sectional view of the base cup 30 (I-I cross-sectional view of FIG. 2)
2 is a plan view of the same.

The base cup 30 is formed by stretching a PET sheet by thermoforming, and has a bottomed cylindrical shape having a bottom portion 31 and a peripheral wall portion 40. The bottom portion 31 is provided with an annular grounding surface portion (grounding portion) 33 at the outermost edge portion thereof, and the outer edge of the grounding surface portion 33 is continuous with the lower edge of the peripheral wall portion 40.
Further, the center of the bottom portion 31 is a circular center bottom surface portion 34, and the center bottom surface portion 34 is located slightly above the ground contact surface portion 33.

The outer peripheral edge of the central bottom surface portion 34 is connected with a taper wall portion 35 whose diameter increases slightly as it goes upward, and the upper edge of the taper wall portion 35 is connected with a concave spherical surface portion 36 formed in a concave spherical shell shape. The outer peripheral edge of the concave spherical surface portion 36 is connected to the inner peripheral edge of the ground contact surface portion 33 via a standing wall portion 37.

The inner surface of the concave spherical surface portion 36 is formed into a concave spherical shape having a predetermined radius of curvature so as to substantially come into contact with the outer surface of the bottom portion 12 of the bottle body 10 having a spherical shell shape. The upright wall portion 37 is arranged so as to be substantially perpendicular to the ground contact surface portion 33, and has a taper whose diameter is slightly reduced as it goes upward. As shown in FIG. 2, the standing wall portion 37
The concave portions 37a and the convex portions 37b, which are concave and convex in a substantially rectangular shape in the radial direction, are alternately formed in the circumferential direction. With this structure, the strength of the standing wall portion 37 against buckling is increased.

The bottom portion 31 has five outlets 38, two in the central bottom surface portion 34 and three in the ground contact surface portion 36. The peripheral wall portion 40 has a cylindrical shape whose diameter gradually increases as it goes upward, and has a large diameter portion 41 at its upper edge portion.
As shown in FIG. 2, in the large-diameter portion 41, concave portions 41a and convex portions 41b that are concave and convex in a substantially rectangular shape in the radial direction are alternately formed in the circumferential direction.

The base cup 30 is attached to the bottle body 10 as follows. That is, the lower edge of the hooking convex portion 14 of the bottle body 10 almost abuts against the upper edge of the large diameter portion 41 of the base cup 30, and the bottom portion 12 of the bottle body 10 is
And the concave spherical surface portion 36 of the base cup 30 are joined by ultrasonic joining or a hot melt material.

As described above, the bottle container 1 is composed of the bottle body 1
Since 0 and the base cup 30 are both made of PET,
Easy to recycle.

In this bottle container 1, the base cup 30
The upper edge of the concave portion 41a of the large diameter portion 41 almost contacts the outer surface of the bottle body 10, and a gap is formed between the upper edge of the convex portion 41b of the large diameter portion 41 and the outer surface of the bottle body 10. This gap becomes the liquid inlet 42.

The liquid inlet 42 and the outlet 38 are effectively used when heat sterilizing the inner solution filled in the bottle body 10 or when heating the bottle body 10 to prevent dew condensation after filling the inner solution. Function. Hereinafter, this will be described.

[Heating Sterilization Treatment and Dew Condensation Prevention Heating Treatment] When the bottle body 10 is filled with a carbonated beverage in which fruit juice, milk components, and other components are mixed, after filling the bottle body 10 with the contents, Hot water is supplied to the outer surface of the bottle body 10 in a shower shape, and the heat sterilizes the contents.

Further, when the bottle body 10 is filled with carbonated water, it is generally performed by low temperature filling, but after filling, the bottle body 1 is filled.
In order to prevent dew condensation on the outer surface of No. 0, warm water is supplied to the outer surface of the bottle main body 10 in a shower shape to warm it after filling.

In such a case, if the bottom portion 12 of the bottle body 10 which is the portion covered by the base cup 30 is not heated or heated, the low temperature internal solution will remain in the bottom portion 12 of the bottle body 10. Incomplete sterilization and heating. In order to achieve complete sterilization and heating, the bottom portion 12 of the bottle body 10 also needs to be heated or heated to generate convection in the internal solution.

In the bottle container 1, heating or heating of the bottom portion 12 of the bottle body 10 is achieved as follows. When hot water or hot water (hereinafter, referred to as hot water) is supplied from above the bottle container 10 in the form of a shower, the hot water flows down the outer surface of the bottle body 10 to the straight body portion 13 of the bottle body 10. Reach the bottom. Further, the hot water travels along the outer surface of the bottle body 10 and gets over the hooking convex portion 14 to pass from the liquid inlet 42 to the base cup 30.
It invades inside and flows downward along the outer surface of the bottom portion 12.

When most of the hot water transmitted through the bottom 12 hits the standing wall 37 of the base cup 30, the standing wall 3
7 and falls onto the ground contact surface 33,
It is discharged to the outside of the base cup 30 from the discharge port 38 provided in the.

A portion of the hot water transmitted through the bottom portion 12 passes through the gap formed between the bottom portion 12 of the bottle body 10 and the concave spherical surface portion 36 of the base cup 30, and then the bottom portion 12 of the bottle body 10 is passed.
Flows to the lowest point, falls on the central bottom surface portion 34 of the base cup 30, and is discharged to the outside of the base cup 30 from a discharge port 38 provided in the central bottom surface portion 34.

As described above, in the bottle container 1 with the base cup, since the bottom portion 12 of the bottle body 10 can be heated or heated, the heat sterilization treatment of the inner solution and the dew condensation prevention heating treatment are surely performed. Can be achieved.

[First Manufacturing Method of Base Cup] Next,
A first method of manufacturing the base cup 30 will be described with reference to FIGS. 4 to 9.

The base cup 30 has a P thickness of 1.0 mm.
It is manufactured by thermoforming an ET sheet using a female mold. First, the manufacturing apparatus will be described. Female 50
The inner surface of is a molding surface 51 having the same shape and size as the outer shape of the base cup 30 to be molded. The female die 50 has a large number of exhaust holes 52. For convenience of illustration, only one exhaust hole 52 is drawn in the figure.

The female die 50 is fixed to the lower die 55, and the upper end portion 53 of the female die 50 projects from the holding portion 56 of the lower die 55 by a predetermined dimension. The lower die 55 has an exhaust hole 5 of the female die 50.
2 has an exhaust hole 57 communicating with the exhaust hole 57.
Is connected to a suction device (not shown) so that the air in the female mold 50 can be sucked.

The upper mold 60 is installed so as to be able to move up and down, and can cooperate with the lower mold 55 to close and open the mold.
The inner diameter of the pressing portion 61 of the upper die 60 is larger than the outer diameter of the upper end portion 53 of the female die 50, and when the die is closed, a gap of a predetermined dimension is formed between the inner surface of the upper die 60 and the outer surface of the female die 50. To be formed. This gap is the PET sheet 90 when the mold is closed.
This makes it possible to stretch.

A plug 62 is installed on the upper mold 60 so as to be able to move up and down, and an air supply hole 63 is provided. The air supply hole 63 is connected to an air supply device (not shown) so that pressurized air can be supplied into the upper mold 60.

A clamp device 65 for sandwiching the PET sheet 90 in a tensioned state is installed between the lower mold 55 and the upper mold 60 so as to be movable up and down, and a heater 70 for heating and softening the PET sheet 90 is retracted. It is installed as possible.

Next, the manufacturing process of the base cup 30 will be described in order. <1. Softening Step> As shown in FIG. 4, the PET sheet 90 clamped in a tension state by the clamp device 65 is set between the lower mold 55 and the upper mold 60 in the mold open state, and the heater 70 is used to set the P sheet 90.
ET sheet 90 at a predetermined temperature (for example, 70 to 90 ° C)
Heat to soften. After softening is completed, the heater 70 is moved to the lower mold 5
5 and the upper mold 60 are evacuated.

<2. First Stretching Step> When the upper die 60 is lowered and the pressing portion 61 is brought into substantially contact with the PET sheet 90 as shown in FIG. 5, the clamp device 65 is lowered in synchronization with the upper die 60.

The PET sheet 90 is the upper end portion 53 of the female die 50.
6, the upper die 60 and the clamp device 65 are lowered until the holding portion 61 of the upper die 60 finally abuts on the holding portion 56 of the lower die 55 and closes the die as shown in FIG.

The PET sheet 90 is the upper end portion 53 of the female die 50.
The PET sheet 90 is extruded and stretched by the female mold 50 until the pressing portion 61 and the pressing portion 56 come into contact with each other after the contact with the. As a result, the PET sheet 90 is oriented and an increase in density occurs. This is the first stretching step.

The corners of the upper end 53 of the female die 50 are preferably chamfered in an arc shape. By doing so, the PET sheet 90 slips well on the upper end portion 53, and the stretching effect can be improved.

<3. Second Stretching Step> Next, as shown in FIG. 7, the plug 62 is lowered in the mold closed state, and the PET sheet 90 is stretched and pushed into the female mold 50. This is the second stretching step, and the PET sheet 90 is oriented in the second stretching step as well, and the density is increased.

<4. Final Stretching Step> Thereafter, while supplying pressurized air from the air supply hole 63 of the upper mold 60, the female mold 50
By exhausting the air in the female mold 50 from the exhaust hole 52 of the lower mold 55 and the exhaust hole 57 of the lower mold 55, as shown in FIG.
The T sheet 90 is drawn and brought into close contact with the molding surface 51 of the female mold 50. This is the final stretching step, and the PET sheet 90 is oriented in the final stretching step as well, causing an increase in density.

By performing this final stretching step, the PET sheet 90 is molded into the base cup 30.

<5. Heat setting step> After the final stretching step is completed, the female die 50 is set while continuing the supply of the pressurized air and the exhaust of the female die 50, or by stopping the supply of the pressurized air and the exhaust of the female die 50. Heat is set by heating with a band heater (not shown) or the like. Heat set is, for example, 11
It is achieved by fixing at a temperature of 0 to 135 ° C for about 5 seconds.

<6. Mold Opening Step> The supply of pressurized air and the exhaust of the inside of the female die 50 are stopped, and the upper die 60 and the clamp device 65 are lifted as shown in FIG. 9 to take out the PET sheet 90 from the female die 50. .

<7. Finishing Step> The PET sheet 90 is removed from the clamp device 65, the portion of the base cup 30 is cut from the PET sheet 90, and the discharge port 38 is punched in the grounding surface portion 33 and the central bottom surface portion 34 of the base cup 30 using a punching device. .

<Comparison with Conventional Thermoforming Method for Sheet Material> The conventional thermoforming method for sheet material using a female mold does not include the first stretching step. That is, in the conventional thermoforming method, as shown in FIG. 15, the upper end portion 53 of the female die 50 and the holding portion 56 of the lower die 55 are substantially flush with each other, and in the mold closed state,
The sheet material 90, the upper end portion 53 of the female die 50, the holding portion 56 of the lower die 55, and the holding portion 61 of the upper die 60 are arranged on substantially one plane.

In the conventional method, the sheet material is not stretched at the time of mold closing, and the sheet material 90 is stretched only after the plug 62 is lowered after the mold is closed. There is no first stretching step for positively stretching the sheet material 90 before descending.

Table 1 shows data comparing the thickness of the base cup manufactured by the thermoforming method of the present example with the base cup manufactured by the conventional thermoforming method in terms of wall thickness, density and whitening phenomenon. In either case, a PET sheet having a thickness of 1.0 mm and a density of 1.33 g / cm ³ is used as a material, and the shape of the base cup is the same as that shown in FIGS. 1 and 2.
The dimensions of each part were the same as those shown in FIG. The measurement positions for the wall thickness, the density, and the presence or absence of the whitening phenomenon are A to I in FIG.
And

Further, in carrying out the manufacturing method of this embodiment, the surface magnification is set to about 3 times by projecting the upper end portion 53 of the female die 50 by 15 mm from the holding portion 56 of the lower die 55. On the other hand, in the case of the conventional thermoforming method, the surface magnification is about 2.66 times.

Here, the surface magnification refers to the surface area (on one surface) of the portion of the PET sheet 90, which is accommodated inside the lower die 55 and the upper die 60 when the die is closed, before the stretch forming. It refers to the ratio of the surface area (of the same one surface) of the portion after stretch molding. That is, it is the area increase rate of the molded portion before and after stretching.

[0062]

[Table 1]

The meanings of the symbols in the column "whether there is a whitening phenomenon" are as follows. ○ Clearly a whitening phenomenon occurred. △ Semi-whitening phenomenon (not completely whitening, but pale)
Occurred. × No whitening phenomenon occurred.

As is clear from Table 1, the base cup 30 manufactured by the manufacturing method of this embodiment has a much higher draw ratio as a whole than the base cup manufactured by the conventional method, and can be made thin. Further, the orientation is sufficiently performed, the density is largely increased, and the strength such as rigidity is increased. Further, the base cup 30 manufactured by the manufacturing method of this embodiment has better transparency and the whitening phenomenon is extremely unlikely to occur.

By the way, also in the base cup of the embodiment, the draw ratio of the concave spherical surface portion 36 corresponding to the measurement position G and the central bottom surface portion 34 corresponding to the measurement position I is low in terms of the wall thickness, The increase in density is also small.

However, regarding the concave spherical surface portion 36, since the concave spherical surface portion 36 is a portion for bonding the bottom portion 12 of the bottle body 10 by ultrasonic bonding or a hot melt material, it is not stretched from the viewpoint of adhesiveness. It is easier to adhere, and it can be said that this is a preferable result.

Also in this embodiment, the central bottom surface portion 34 and the concave spherical surface portion 36 have a whitening phenomenon, but the hardness of these portions increases with the whitening phenomenon.

Further, when heat setting is performed in a state where the draw ratio is low and an appropriate increase in density cannot be obtained as in the conventional method, the shrinkage is large and it is difficult to maintain the shape, and the transparency is impaired. However, when the stretching ratio is large and the density is appropriately increased as in the present example, it does not deform even if heat setting is performed, transparency is not easily impaired, and heat resistance can be imparted by heat setting. .

By the way, during the heat sterilization process, the standing wall portion 37 of the base cup 30 is placed under extremely severe conditions in which the weight of the bottle body 10 and the internal solution is applied as a load under high temperature. Therefore, when the standing wall portion 37 is not stretched as in the conventional case, the standing wall portion 37 buckles due to insufficient strength, and the central bottom surface portion 33 projects below the ground contact surface portion 33, and the base cup 30 There is a problem that the sitting of the person becomes worse.

However, when the stretching ratio of the standing wall portion 37 is large and the density is increased as in this embodiment, the strength of the standing wall portion 37 is also increased, and the standing wall portion 37 buckles even under severe conditions during heat sterilization. There is no such thing.

Moreover, in the base cup 30 of the present embodiment, the standing wall portion 37 stands up at a right angle to the ground contact surface portion 33 and is reinforced by the concave portions 37a and the convex portions 37b. However, the strength against buckling is very large.

In the manufacturing method of this embodiment, the female die 50 is heated or a special surface is formed on the molding surface 51 of the female die 50 in order to make the PET sheet 90 slippery during stretching and enhance the stretching effect. It is also possible to apply a treatment to enhance lubricity.

[Second Manufacturing Method of Base Cup] Next,
A second method of manufacturing the base cup will be described with reference to FIGS. In the manufacturing apparatus used in the second manufacturing method, the female die 50 is movable up and down with respect to the lower die 55 by an actuator (air cylinder, hydraulic cylinder, etc.) 80, and when the actuator 80 is moved downward, The upper end portion 53 of 50 and the pressing surface 56 of the lower die 55 are flush with each other. This point is different from the manufacturing apparatus used in the first manufacturing method.

The softening step is the same as that of the first manufacturing method, and therefore its explanation is omitted. After the softening process, the upper mold 60 and the clamp device 65 are synchronously lowered, and as shown in FIG. 10, the pressing portion 61 of the upper mold 60 is brought into contact with the pressing portion 56 of the lower mold 55 to close the mold.

In the first manufacturing method, the PET sheet 90 is pushed up and stretched by the female mold as the mold is closed, but in the case of the second manufacturing method,
Since the female mold 50 does not protrude from the lower mold 55 when the mold is closed, the PET sheet 90 is not stretched.

In the second manufacturing method, as shown in FIG. 11, the female mold 5 is formed by the actuator 80 after the mold is closed.
By increasing 0, the PET sheet 90 is pushed up. This is the first stretching step in the second manufacturing method, whereby the PET sheet 90 is stretched, oriented, and the density is increased.

After this, as shown in FIG. 12, the plug 62 descends and the second drawing step is started. Since each step after the second stretching step is the same as that of the first manufacturing method, the description thereof will be omitted.

According to the second manufacturing method as well, similar to the first manufacturing method, it is possible to manufacture the base cup 30 having physical properties superior to those manufactured by the conventional method.

[Modification of Second Manufacturing Method] The molding apparatus used in the second manufacturing method may be used for thermoforming as follows. That is, the PET sheet 90 is pushed into the female mold 50 by the plug 62 as shown in FIG. 13 before the female mold 50 is pushed up by the actuator 80 from the mold closed state of FIG. Then, after that, the female die 50 is pushed upward by the actuator 80 to obtain the state of FIG.

In this way, the front and rear of the first stretching step and the second stretching step are reversed, but one stretching step is required as compared with the conventional method.
The base cup 30 having the physical properties superior to those produced by the conventional method can be produced, and the action and effect of increasing the draw ratio can be obtained.

[0081]

As described above, according to the present invention,
Since both the bottle body and the base cup can be made of PET, the excellent effect of facilitating the recycling of the bottle container is achieved.

Further, when the base cup is heat-set, the heat resistance is improved. Since the standing wall portion provided on the bottom portion of the base cup is substantially erected with respect to the ground contact portion, an excellent effect of increasing the strength of the standing wall portion against buckling is achieved.

When a recess and a protrusion are provided on the standing wall,
The strength of the standing wall portion against buckling can be further increased. If the base cup is provided with a liquid inlet and a discharge port, the bottom of the bottle body can be heated or heated when performing heat sterilization treatment or dew condensation prevention heating treatment, so that each of the above treatments can be performed reliably. The effect is that you can do it.

When the base cup is manufactured by the thermoforming method, if a step of sticking out the heat-softened PET sheet by a female mold and stretching it is provided, the stretching ratio can be improved and the density can be appropriately increased. The cup strength can be increased, and the heat resistance and transparency can be increased.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a base cup according to an embodiment of the present invention.

FIG. 2 is a plan view of a base cup according to an embodiment of the present invention.

FIG. 3 is a partially cutaway front view of a bottle container with a base cup according to an embodiment of the present invention.

FIG. 4 is an explanatory view of the first manufacturing method of the base cup according to the present invention, and is a drawing showing a softening step.

FIG. 5 is an explanatory view of the first manufacturing method of the base cup according to the present invention, and is a view showing the middle of mold closing.

FIG. 6 is an explanatory diagram of a first method of manufacturing a base cup according to the present invention, and is a diagram showing a first stretching step.

FIG. 7 is an explanatory view of the first manufacturing method of the base cup according to the present invention, and is a drawing showing a second stretching step.

FIG. 8 is an explanatory view of the first manufacturing method of the base cup according to the present invention, and is a drawing showing a final stretching step.

FIG. 9 is an explanatory view of the first manufacturing method of the base cup according to the present invention, and is a drawing showing a mold opening step.

FIG. 10 is an explanatory view of the second manufacturing method of the base cup according to the present invention, and is a drawing showing a mold closed state.

FIG. 11 is an explanatory view of the second manufacturing method of the base cup according to the present invention, and is a drawing showing the first stretching step.

FIG. 12 is an explanatory view of the second manufacturing method of the base cup according to the present invention, and is a drawing showing a second stretching step.

FIG. 13 is an explanatory view of a modification of the second manufacturing method of the base cup according to the present invention.

FIG. 14 is a diagram showing an example of actual dimensions of the base cup according to the embodiment of the present invention.

FIG. 15 is a diagram showing a conventional thermoforming method for a sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bottle container 10 Bottle main body 12 Bottom part 30 Base cup 31 Bottom part 33 Grounding surface part (grounding part) 36 Concave spherical surface part 37 Standing wall part 37a Recessed part 37b Convex part 38 Discharge port 41 Large diameter part (upper edge part) 41a Recessed part 41b Convex part 42 Liquid Inlet 50 Female 51 Forming Surface 62 Plug 90 PET Sheet

Claims (8)

[Claims] 1. A polyethylene terephthalate sheet in a base cup, which has a bottom portion and a peripheral wall portion, has a bottomed cylindrical shape, and is attached to a bottom portion projecting in a hemispherical shell shape of the bottle body to be a leg body of the bottle body. A base cup formed by stretching by heat forming. 2. The base cup according to claim 1, which is heat-set. 3. The base cup according to claim 1 or 2, wherein a concave spherical surface portion that abuts on the bottom portion of the bottle body having a hemispherical shell shape, and a ground portion that surrounds the outside of the concave spherical surface portion. A base cup, wherein the outer edge of the concave spherical surface portion and the inner edge of the ground contact portion are connected by an annular standing wall portion that stands up at a right angle to the ground contact portion. 4. The base cup according to claim 3, wherein concave portions and convex portions that are uneven in the radial direction are alternately formed in the standing wall portion in the circumferential direction. 5. The base cup according to claim 1, wherein the upper portion of the peripheral wall portion of the base cup is
A liquid inlet that guides the liquid dropped from above the bottle body into the base cup along the bottom surface of the bottle body when attached to the bottle body is provided, and the bottom portion of the base cup has entered the base cup. A base cup having a discharge port for discharging liquid. 6. The base cup according to claim 5, wherein concave portions and convex portions which are uneven in the radial direction are alternately formed on the upper edge portion of the peripheral wall portion of the base cup in the circumferential direction. A base cup having an upper edge serving as the liquid inlet. 7. A polyethylene terephthalate heat-softened using a female mold having a molding surface having substantially the same shape and size as the outer shape of a bottomed cylindrical base cup to be molded, and a plug capable of penetrating into the female mold. In a method of manufacturing a base cup, in which a sheet made of metal is pressed into the female mold with the plug, and the sheet is brought into close contact with the molding surface of the female mold to form a base cup having a desired shape, the heat-softened sheet is molded with the female mold. A method of manufacturing a base cup, comprising a step of protruding and stretching. 8. A bottle body made of polyethylene terephthalate having a bottom portion projecting in a hemispherical shell shape, and the base cup according to claim 1 attached to the bottom portion of the bottle body. Bottle container characterized by.