JP6912871B2 - Manufacturing method of multiple bottles made of synthetic resin - Google Patents

Description

The present invention relates to a method for producing a synthetic resin multi-bottle.

Conventionally, an inner container body that is deformed by volume reduction due to external pressure (hereinafter, may be referred to as “volume reduction deformation”) is arranged inside the outer bottle that can be restored to its original shape with respect to the external pressure, and the outer bottle and the inner container are arranged. Multiple bottles made of synthetic resin that allow outside air to be introduced between the body and the body are known.

In the synthetic resin multiple bottle, by pressing the body of the outer bottle, the inner container body is reduced in volume and deformed to eject the contents contained in the inner container body, while the pressing is released. Outside air is introduced between the outer bottle and the inner container by the action of a check valve or the like provided separately. As a result, the outer bottle returns to its original shape due to the external air pressure, while the inner container body is maintained in a volume-reduced and deformed state. In this case, since the outside air does not enter the inner container, it is possible to prevent the contents contained in the inner container from being denatured due to oxidation or the like.

The synthetic resin multiple bottle is manufactured, for example, by forming an inner preform and an outer preform by injection molding of a synthetic resin, and blow molding with the inner preform arranged on the inner peripheral side of the outer preform. NS. However, when the synthetic resin multiple bottle is manufactured by blow molding as described above, the inner container body is brought into close contact with the outer bottle due to the heat and pressure during blow molding, and the outer bottle and the inner container body are brought into close contact with each other. There is a problem that it may be difficult to peel off. The problem is remarkable when the resin forming the synthetic resin multiple bottle is a polyester resin, for example, a polyester resin mainly composed of polyethylene terephthalate.

Further, in the synthetic resin multiple bottle, when the inner container body is volume-reduced and deformed as described above, the volume-reducing deformation is in the length direction or the radial direction of the body of the inner container body (in the case of a square bottle, the width direction). ), There is a problem that the contents may not be sufficiently poured out.

In order to solve the above problem, a synthetic resin multiple bottle in which a recess or a groove is formed on the outer peripheral surface of the inner container body and is deformed along the recess or the groove is known (for example, Patent Document 1). reference).

Japanese Patent No. 3872651

However, the conventional multiple bottle made of synthetic resin has a disadvantage that the outer bottle and the inner container body are difficult to peel off, and the volume reduction deformation may become non-uniform or the volume reduction deformation itself may become difficult.

INDUSTRIAL APPLICABILITY The present invention eliminates such inconvenience, and the inner container body is easily peeled off from the outer bottle, and the volume is surely reduced and deformed, so that the amount of residual liquid in the contents can be reduced . It is an object of the present invention to provide a manufacturing method.

In order to achieve such an object, the method for producing a synthetic resin multiple bottle of the present invention comprises a cylindrical outer mouth portion, a shoulder portion connected to the outer mouth portion, a body portion connected to the shoulder portion, and the like. An outer bottle that is provided with a bottom portion that is connected to the body portion and a ground contact portion that is connected to the bottom portion and that can return to its original shape with respect to external pressure, and is arranged on the inner peripheral side of the cylindrical outer mouth portion of the outer shell bottle. An inner container body that has a cylindrical inner mouth portion and an inner container body that is connected to the inner mouth portion and has a shape that conforms to the inner surface shape of the outer bottle, and is deformed by external pressure, and the outer mouth portion and the inner mouth portion. The inner container body is provided with a ventilation path formed between the outer bottle and the inner container body to introduce outside air, and the inner container body main body is provided with a deformation guide portion for guiding deformation due to external pressure. A method for manufacturing a bottle, in which an inner preform forming the inner container is arranged on the inner peripheral side of the outer preform forming the outer bottle, and the contents are placed on the inner peripheral side of the outer preform by blow molding. The step of forming a synthetic resin multiple bottle in which the body is arranged, and at least the inner container body being maintained at a temperature equal to or higher than the glass transition temperature of the resin constituting the inner container body, from the air passage. A step of peeling the inner container body from the outer bottle and deforming it by introducing a pressurized gas between the outer bottle and the inner container body or depressurizing the inside of the inner container body. And, in a state where the inner container body is maintained at a temperature lower than the glass transition temperature of the resin constituting the inner container body, the space between the outer bottle and the inner container body main body is provided through the air passage. A step of returning the inner container body to its original shape by reducing the pressure or introducing a pressurized gas into the inner container body, and forming the deformation guide portion on the inner container body as a trace of the deformation. It is characterized by having and.

The content of the synthetic resin multiple bottle is such that the inner container body of the inner container body is reduced in volume and deformed by pressing the outer port portion and the inner mouth portion downward and pressing the body portion of the outer bottle. Things are poured out. Next, when the pressure on the body of the outer bottle is released, outside air is introduced from the ventilation passage between the outer bottle and the inner container body, and the outer bottle returns to its original shape due to the outside air pressure. The inner container body is maintained in a state of being reduced in volume and deformed.

In the synthetic resin multiple bottle, the inner container body is provided with the deformation guide portion at the time of the volume reduction deformation, so that the inner container body can be easily peeled off from the outer bottle. The volume reduction deformation is induced by the deformation guide portion, and the volume reduction deformation can be reliably performed.

In the method for producing a multi-bottle made of synthetic resin of the present invention, first, the inner preform forming the inner container body is arranged on the inner peripheral side of the outer preform forming the outer bottle, and the outer preform is blow-molded. A synthetic resin multiple bottle in which the inner container body is arranged on the inner peripheral side of the bottle is formed. At this time, the inner container body body does not yet include the deformation guide portion.

Next, the inner container body is enclosed by introducing a pressurized gas between the outer bottle and the inner container body from the ventilation passage or by reducing the pressure inside the inner container body. Deform by peeling from the bottle.

Next, the space between the outer bottle and the inner container body is decompressed through the ventilation passage, or a pressurized gas is introduced into the inner container body to introduce the inner container body. Restore the main body to its original shape. In this manner, the inner container body and remains a favorite phrase folding traces of the deformation, it is possible to form a synthetic resin multi-bottle Ru with the deformation guide portion as traces of deformation.

In the method for producing a synthetic resin multiple bottle of the present invention, at least the inner container body constituting the synthetic resin multiple bottle was maintained at a first temperature equal to or higher than the glass transition temperature of the resin constituting the inner container body. In this state, the inner container body is peeled off from the outer bottle and deformed, and the inner container body is cooled to a second temperature lower than the glass transition temperature of the resin constituting the inner container body, and the inner container body is cooled. body with a state maintained at a temperature of the second, the inner container body is original return, you form the deformation guide portion as traces of deformation in the inner container body.

In the method for producing a multi-bottle made of synthetic resin of the present invention, the inner container is deformed by peeling the inner container body from the outer bottle while maintaining at least the inner container body at the first temperature. The body body can be easily reduced in volume and deformed.

Next, by cooling the volume-reduced and deformed inner container body to a second temperature equal to or lower than the first temperature, the inner container body body is maintained and fixed in the volume-reduced and deformed state.

Therefore, when the inner container body is restored to its original shape while the inner container body is maintained at the second temperature, traces of deformation due to the volume reduction deformation remain as folds on the inner container body body. , The deformation guide portion is formed as a trace of the deformation.

In the synthetic resin multiple bottle of the present invention, both the outer bottle and the inner container can be made of polyester resin. When the outer bottle and the inner container are made of a polyester resin, for example, a polyester resin mainly composed of polyethylene terephthalate resin, the inner container is brought into close contact with the outer bottle by the heat and pressure during blow molding. There is a concern that the outer bottle and the inner container may not easily peel off from each other in the synthetic resin multiple bottle.

However, in the synthetic resin multiple bottle of the present invention, since the inner container body body is provided with the deformation guide portion, even when the outer bottle and the inner container body are made of polyester resin, the deformation guide portion is used. The volume reduction deformation will be induced. Therefore, the inner container body can be easily peeled off from the outer bottle, and the volume can be reliably reduced and deformed.

Further, in the method for manufacturing a multiple bottle made of synthetic resin of the present invention, the outer bottle has, for example, a shoulder portion having a polygonal pyramid shape at least in a portion connected to the outer opening portion and a circular cross section orthogonal to the axis. A bottle on the inner peripheral side of the ground contact portion and the bottom portion having a polygonal pyramid shape having a ridge line extending from the body portion and at least a portion connected to the ground contact portion on an extension of the polygonal pyramid-shaped ridge line of the shoulder portion. It is possible to have a configuration in which at least the lowermost stage of the pyramid-shaped recesses bulging and laminated in a plurality of stages is provided with a concave portion having a polygonal pyramid shape.

Perspective view showing the structure of a synthetic resin multi-bottle. FIG. 1 is a sectional view taken along line II-II of FIG. A is a schematic cross-sectional view showing an initial state of the synthetic resin multiple bottle manufacturing method of the present invention, B is a schematic cross-sectional view showing a blow molding process, and C is a schematic cross-sectional view showing a completed state of the blow molding process. A is a schematic cross-sectional view showing a step of heating the inner container body in the method for manufacturing a multiple bottle made of synthetic resin of the present invention, and B is a schematic view showing a step of peeling the inner container body body from the outer bottle to reduce and deform the volume. A cross-sectional view, C is a schematic cross-sectional view showing a process of returning the inner container body to its original shape. Perspective view illustrating the use of synthetic resin multi-bottle. A is a cross-sectional view taken along the line AA of FIG. 5, and B is a cross-sectional view taken along the line BB of FIG.

Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

As shown in FIGS. 1 and 2, the synthetic resin multiple bottle 1 of the present embodiment has an outer bottle 2 that can be restored to its original shape with respect to an external pressure and an inner container body that is housed inside the outer bottle 2 and deformed by the external pressure. It consists of 3.

The outer bottle 2 is made of, for example, polyethylene terephthalate resin, and has a cylindrical outer mouth portion 4, a shoulder portion 5 connected to the outer mouth portion 4, a cylindrical body portion 6 connected to the shoulder portion 5, and a cylindrical body portion. It has a bottom 7 connected to 6. The bottom portion 7 is provided with a recess 8 on the inner peripheral side that bulges inside the outer bottle 2 to impart independence to the synthetic resin multiple bottle 1, and a grounding portion 9 is formed between the bottom portion 7 and the recess 8. There is.

The outer opening portion 4 is provided with a male screw portion 10 and a support ring 11 on the outer peripheral surface, and the shoulder portion 5 has a quadrangular pyramid-shaped portion 12 in contact with the outer opening portion 4, and is below the quadrangular pyramid portion 12. The diameter of the quadrangular pyramid portion 12 gradually increases toward the cylindrical body portion 6, and the corners of the quadrangular pyramid become smooth, and the body portion upper portion 13 connected to the cylindrical body portion 6 is provided.

The cylindrical body portion 6 has a circular cross section orthogonal to the axis, and is connected to the shoulder portion 5 via the step portion 6a, while being connected to the bottom portion 7 via the step portion 6b. The step portion 6a is gradually reduced in diameter from the shoulder portion 5 toward the cylindrical body portion 6, and the step portion 6b is gradually reduced in diameter from the bottom portion 7 toward the cylindrical body portion 6.

Further, the cylindrical body portion 6 gradually reduces in diameter from the lower end portion of the step portion 6a connected to the shoulder portion 5 toward the central portion 6c, and faces the upper end portion of the step portion 6b connected to the bottom portion 7 from the central portion 6c. It has a drum shape that gradually expands in diameter. Further, the cylindrical body portion 6 is provided with a plurality of ribs 14 along the axial direction, and the ribs 14 are formed over the entire circumference of the cylindrical body portion 6.

The bottom portion 7 has a quadrangular pyramid-shaped portion 15 in contact with the ground contact portion 9, and the diameter of the bottom portion 7 gradually increases from the quadrangular pyramid-shaped portion 15 toward the cylindrical body portion 6 above the quadrangular pyramid-shaped portion 15. The lower part 16 of the body portion 16 is provided, which has smooth corners and is connected to the cylindrical body portion 6. Further, the recess 8 is provided with quadrangular pyramid trapezoidal recesses 8a, 8b, 8c laminated in three stages.

Further, each of the quadrangular pyramid-shaped portions 12 and 15 has a quadrangular cross section orthogonal to the axis, and R is attached to the apex thereof, and the apex is provided with ridge lines 12a and 15a. Here, the ridge line 15a is continuous on the extension of the ridge line 12a as shown by the alternate long and short dash line in FIG.

On the other hand, the inner container body 3 is made of, for example, polyethylene terephthalate resin, and is connected to the cylindrical inner mouth portion 17 arranged on the inner peripheral side of the outer mouth portion 4 and the inner mouth portion 17, and is connected to the shoulder of the outer bottle 2. A portion 5, a cylindrical body portion 6, a bottom portion 7, a recess 8, and an inner container body body 18 having a shape conforming to the inner surface shape of the ground contact portion 9 are provided. The inner opening portion 17 includes an extending portion 19 extending above the upper end of the outer opening portion 4 and a flange portion 20 extending radially outward from the extending portion 19. It is locked to the upper end edge of the outer opening portion 4 by the portion 20.

Further, the inner opening portion 17 is provided with a vertical groove 21 on the outer peripheral surface. The vertical groove 21 is continuously provided in the horizontal groove 22 formed on the lower surface of the flange portion 20, and the horizontal groove 22 is open to the outside at the outer peripheral edge of the collar portion 20. As a result, the vertical groove 21 and the horizontal groove 22 form a ventilation passage 23 for introducing outside air between the outer bottle 2 and the inner container body 3. Further, the inner container body 3 is provided with a deformation guide portion 24 on the inner container body main body 18.

Next, a method for manufacturing the synthetic resin multiple bottle 1 of the present embodiment will be described with reference to FIGS. 3 and 4.

In the method for manufacturing the synthetic resin multiple bottle 1 of the present embodiment, first, as shown in FIG. 3A, the inner preform 32 forming the inner container body 3 is formed inside the outer preform 31 forming the outer bottle 2. Place and use a blow molding apparatus to perform blow molding.

The outer preform 31 is formed by injection molding using, for example, polyethylene terephthalate resin as a material, and is formed by an outer opening portion 4 and a bottomed cylindrical outer body portion 31a connected below the outer opening portion 4. .. The outer mouth portion 4 of the outer preform 31 has the same shape as the outer mouth portion 4 of the outer bottle 2, and the same reference numerals are given to the same configurations, and detailed description thereof will be omitted.

The inner preform 32 is formed by injection molding using, for example, polyethylene terephthalate resin, and is formed by an inner mouth portion 17 and a bottomed cylindrical inner body portion 32a connected below the inner mouth portion 17. .. The inner mouth portion 17 of the inner preform 32 has the same shape as the inner mouth portion 17 of the inner container body 3, and the same reference numerals are given to the same configurations, and detailed description thereof will be omitted.

A well-known blow molding apparatus can be used, and as shown in FIG. 3A, the blow molding apparatus includes a mold 33, a blow nozzle 34, and a stretch rod 35.

The mold 33 includes a molding portion 36 having a shape along the shoulder portion 5, the cylindrical body portion 6, the bottom portion 7, the recess 8, and the ground contact portion 9 of the outer bottle 2, and the support ring 11 of the outer opening portion 4 of the outer preform 31. It is provided with a support opening 37 that exposes and supports the upper part from the above. The mold 33 has a split mold structure (not shown), and the synthetic resin multiple bottle 1 after molding can be removed by dividing the mold 33 into a left and right side and a bottom side.

The blow nozzle 34 is raised and lowered by an elevating means (not shown), and airtightly contacts the upper end surface of the flange portion 20 of the inner preform 32 via the O-ring 38. A stretch rod 35 is inserted through the blow nozzle 34, and a gas passage 39 connected to a high-pressure gas supply means (not shown) is formed between the outer peripheral surface of the stretch rod 35 and the inner peripheral surface of the blow nozzle 34. ..

The stretch rod 35 is advanced during blow molding by an advancing / retreating driving means (not shown). In FIG. 3A, the stretch rod 35 protrudes from the tip of the blow nozzle 34, but the stretch rod 35 is retracted when not in use and is housed inside the blow nozzle 34 (upper part in the drawing).

When the synthetic resin multiple bottle 1 is manufactured by the blow molding apparatus having the above configuration, as shown in FIG. 3A, the outer preform 31 in which the inner preform 32 is arranged is set in the mold 33, and then the outer preform 31 is set in the mold 33. The blow nozzle 34 is connected to the inner opening 17 of the inner preform 32. The outer preform 31 and the inner preform 32 are heated to a temperature at which blow molding is possible prior to being set in the mold 33.

Next, as shown in FIG. 3B, pressurized air is introduced into the inner preform 32 from the gas passage 39 of the blow nozzle 34 as shown by a thick arrow (hereinafter, gas flow in FIGS. 3B and C and 4A to 4C). Is indicated by a thick arrow), and at the same time, the stretch rod 35 is extended downward. As a result, the inner preform 32 expands and comes into close contact with the inner surface of the outer preform 31 in the unexpanded state.

Subsequently, from the state shown in FIG. 3B, when the stretch rod 35 is extended downward while further introducing pressurized air into the inner preform 32, the outer preform is formed by the inner body portion 32a of the expanded inner preform 32. The outer body portion 31a of 31 is further expanded.

Then, as shown in FIG. 3C, in the outer preform 31, the outer body portion 31a is molded by the molding portion 36 of the mold 33, and the outer bottle 2 is formed. Further, in the inner preform 32, the inner body portion 32a is formed into a shape that conforms to the inner surface shape of the outer bottle 2, and the inner container body 3 is formed.

As a result, a synthetic resin multi-layer bottle 40 including an outer bottle 2 and an inner container body 3 housed inside the outer bottle 2 is obtained. The synthetic resin multiple bottle 40 has the same shape as the synthetic resin multiple bottle 1 shown in FIGS. 1 and 2, but the deformation guide portion 24 is not yet formed in the inner container body 3.

In the method for manufacturing the synthetic resin multiple bottle 1 of the present embodiment, next, as shown in FIG. 4A, the stretch rod 35 is retracted from the synthetic resin multiple bottle 40 arranged in the mold 33 to retract the blow nozzle 34. Contain inside.

Next, as shown in FIG. 4B, pressurized air is introduced between the outer bottle 2 and the inner container 3 from the ventilation passage 23 between the outer port 4 and the inner port 17. At this time, the outer bottle 2 and the inner container body 3, the gas passage 39 of the probe Ronozuru 34, by ejecting hot air, the inner container body 3, a resin (this embodiment constituting the inner container body 3 It is heated to a first temperature equal to or higher than the glass transition temperature of polyethylene terephthalate resin) and maintained in that state.

In this way, since the inner container body 3 is heated to the first temperature, the inner container body body 18 is peeled off from the outer bottle 2 and easily reduced in volume and deformed. Further, since the inner container body 3 is heated to the first temperature, the flexibility is further improved, and it is possible to prevent damage to the deformed portion due to the volume reduction deformation.

Incidentally, the first temperature is a temperature higher than the glass transition temperature of the resin constituting the inner container body 3, said volume reducing deformation and temperature that do not permanent deformation remains original recoverable deformation Is preferable.

At this time, as shown in FIG. 1, the outer bottle 2 has a quadrangular pyramid-shaped portion 12 connected to the outer mouth portion 4 of the shoulder portion 5, and four portions connected to the ground contact portion 9 of the bottom portion 7. It is a pyramid-shaped portion 15. The ridge line 12a of the quadrangular pyramid portion 12 is on an extension of the ridge line 15a of the quadrangular pyramid portion 15. Further, the inner container body body 18 of the inner container body 3 has a shape that conforms to the internal shape of the outer bottle 2.

Therefore, in the inner container body 18, the portions corresponding to the ridge lines 12a and 15a act as ribs, and the strength is higher than the portions sandwiched between the ridge lines 12a and 12a and the portions sandwiched between the ridge lines 15a and 15a. Become.

As a result, as shown in FIG. 4B, the portion sandwiched between the ridge lines 12a and 12a having lower strength and the portion corresponding to the portion sandwiched between the ridge lines 15a and 15a are immersed in the inside, so that the volume is reduced due to the valley bending deformation. Deformation occurs. The valley fold deformation is from a portion of the inner container body 18 corresponding to the portion sandwiched between the ridge lines 12a and 12a and a portion corresponding to the portion sandwiched between the ridge lines 15a and 15a to a portion corresponding to the cylindrical body portion 6. Proceed towards. As a result, a cross-shaped valley fold portion 18a is formed over the entire length of the inner container body body 18.

At this time, since the synthetic resin multiple bottle 40 is provided with the recess 8 having the shape of the quadrangular pyramid trapezoidal recesses 8a, 8b, 8c, the inner container body 18 becomes the outer bottle 2 by heat crimping at the time of blow molding. It is in close contact with. Further, since the recess 8 is composed of quadrangular pyramid trapezoidal recesses 8a, 8b, 8c and has a large number of stepped portions and bent portions, pressure is applied between the outer bottle 2 and the inner container body 18 in the recess 8. Air does not enter. Therefore, while the valley fold portion 18a is formed, the inner container body 18 does not peel off from the outer bottle 2 in the recess 8, and the valley fold portion 18a can be reliably formed.

The volume reduction deformation of the inner container body 3 (inner container body body 18) is performed at the same time as the operation of introducing pressurized air between the outer bottle 2 and the inner container body 3 from the ventilation passage 23, and at the same time, the gas of the blow nozzle 34. This may be done by depressurizing the inside of the inner container body 3 through the passage 39. Further, the volume reduction deformation of the inner container body 3 (inner container body main body 18) may be performed only by introducing pressurized air between the outer bottle 2 and the inner container body 3 from the ventilation passage 23, and blow. It may be performed only by depressurizing the inside of the inner container body 3 through the gas passage 39 of the nozzle 34.

Next, the inner container body 3 which has been volume-reduced and deformed as described above and has a valley-folded portion 18a formed in the inner container body body 18 is cooled to a temperature equal to or lower than the temperature when the volume-reduced and deformed as described above. Here, when the inner container body 3 is heated to the first temperature, it is cooled to a second temperature equal to or lower than the first temperature. When the first temperature is a temperature equal to or higher than the glass transition temperature, the second temperature is a temperature lower than the glass transition temperature, preferably a temperature in the range of 30 to 60 ° C. In this way, the inner container body 3 is fixed in a state where the valley fold portion 18a is formed on the inner container body main body 18, and is in a state of having a so-called folding habit.

Therefore, next, pressurized air is introduced into the inner container body 3 through the gas passage 39 of the blow nozzle 34 to restore the inner container body body 18 to its original shape. In this way, as shown in FIG. 4C, a deformation guide portion 24 is formed on the inner container body body 18 as a trace of the deformation (valley bent portion 18a) due to the volume reduction deformation, and the book shown in FIGS. 1 and 2 is formed. The synthetic resin multiplex bottle 1 of the embodiment can be obtained.

Here, when the inner container body 3 is volume-reduced and deformed at a temperature equal to or higher than the glass transition temperature as described above, the inner container body 18 is at a temperature lower than the glass transition temperature, preferably in the range of 30 to 60 ° C. By returning the glass to its original shape, the inner container body 18 can be returned to a shape closer to the original shape while being provided with the deformation guide portion 24, and the change in capacity with respect to the shape before the volume reduction deformation can be reduced.

When returning the inner container body 3 to its original shape, at the same time as the operation of introducing pressurized air into the inner container body 3 through the gas passage 39 of the blow nozzle 34, the contents of the outer container body 2 are changed from the ventilation passage 23. The space between the body 3 and the body 3 may be sucked to reduce the pressure.

As shown in FIG. 4B, the method for manufacturing the synthetic resin multiple bottle of the present embodiment includes a step of peeling the inner container body 18 of the synthetic resin multiple bottle once from the outer bottle 2 to reduce and deform the volume. .. However, depending on the type, combination, blow molding conditions, etc. of the polyester resin used for the inner container 3 and the outer bottle 2, the adhesion between the inner container 3 and the outer bottle 2 after blow molding becomes large, and FIG. 4B shows. In the step of reducing the volume and deforming, it is necessary to increase the pressure of the pressurized air, and there is a concern that the inner container 3 may be damaged.

Therefore, in the method for producing a synthetic resin multiple bottle of the present embodiment, the releasability and peelability of the polyester resin are enhanced between the outer preform 31 and the inner preform 32 during blow molding shown in FIG. 3A. It is preferable to apply a release agent, a release agent, or the like. As the release agent, release agent and the like, for example, a release agent containing liquid paraffin having a Seibolt universal viscosity in the range of 75 to 300 SUS, preferably 159 to 175 SUS at 100 ° F. is preferable. The mold release agent may consist only of the liquid paraffin, may contain a solvent for the liquid paraffin, or may contain an additive having another mold release effect that dissolves in the liquid paraffin. good. As the liquid paraffin, for example, HYCOAL K-290 (trade name) manufactured by Kaneda Co., Ltd. can be used.

Next, the usage state and the action and effect of the synthetic resin multiple bottle 1 of the present embodiment will be described with reference to FIGS. 5, 6A and 6B.

The synthetic resin multiple bottle 1 of the present embodiment contains contents (not shown) in the inner container body 3, and when the contents are poured out, as shown in FIG. 5, the outer mouth portion 4 and the inner mouth portion 4 and the inner mouth Tilt the portion 17 downward. Then, when the cylindrical body 6 of the outer bottle 2 is gripped and pressed, the inner container body 18 is volume-reduced and deformed, so that the contents are poured out. In the synthetic resin multiple bottle 1, since the cylindrical body 6 has a circular cross section orthogonal to the axis, it can be pressed against the axis from any direction, and the cylindrical body 6 has a drum shape. Since a plurality of ribs 14 formed along the axial direction are provided, the central portion 6c thereof can be easily gripped to reduce the volume and deform of the inner container body body 18, and excellent squeezing property can be obtained. can.

Next, when the pressure on the cylindrical body 6 of the outer bottle 2 is released, outside air is introduced from the ventilation passage 23 between the outer bottle 2 and the inner container body 18, and the outer bottle 2 returns to its original shape due to the outside air pressure. However, the inner container body 18 is maintained in a state of being reduced in volume and deformed.

At this time, since the contents are concentrated in the direction of the inner mouth portion 17 due to gravity, the inner container body body 18 is formed on the ridge lines 15a and 15a at the portion corresponding to the quadrangular pyramid portion 15 of the bottom portion 7 of the outer bottle 2. The valley fold deformation starts when the valley fold portion 18a is formed in the central portion of the side surface portion 18b corresponding to the sandwiched portion and immerses in the inside.

In the synthetic resin multiple bottle 1 of the present embodiment, the portion of the outer bottle 2 that is connected to the grounding portion 9 of the bottom 7 is a quadrangular pyramid portion 15, and the inner container body 18 has the internal shape of the outer bottle 2. It has a shape that follows it. Therefore, in the valley bending deformation, the portion of the inner container body 18 corresponding to the ridge line 15a acts as a rib, and the strength is higher than that of the side surface portion 18b corresponding to the portion sandwiched between the ridge lines 15a and 15a. As shown by the virtual line, it starts with the formation of the valley fold portion 18a in the central portion of the side portion 18b having a lower strength.

Further, at this time, the inner container body 18 is provided with the deformation guide portion 24 formed as shown in FIGS. 4A to 4C, and the deformation guide portion 24 is provided with a folding habit of forming the valley fold portion 18a. .. Therefore, in the synthetic resin multiple bottle 1, the valley fold portion 18a can be easily and surely formed by being guided by the fold habit of the deformation guide portion 24.

In the synthetic resin multiple bottle 1, the contents are gradually reduced by repeatedly pressing the cylindrical body portion 6 of the outer bottle 2 and releasing the pressing. When the contents are reduced, the valley bending deformation of the inner container body 18 starts from the portion corresponding to the quadrangular pyramid portion 15 of the bottom 7 of the outer bottle 2, and is from the outside to the inside of the inner container body 18 in the width direction. As shown in FIG. 6A, the adjacent side surface portions 18b and 18b come into contact with each other and are deformed in a cross-sectional view.

Further, the valley bending deformation of the inner container body 18 starts from the portion corresponding to the quadrangular pyramid portion 15 of the bottom 7 of the outer bottle 2, and is guided by the bending habit of the deformation guide portion 24, and is inside in the length direction. Proceed toward the mouth 17. At this time, the valley-folded and deformed portions 18a and 18b of the inner container body 18 are separated from the inner surface of the outer bottle 2 as the valley-folding deformation progresses, as shown in FIG. 6A.

When the contents are further reduced, the valley bending deformation of the inner container body 18 eventually reaches the portion corresponding to the cylindrical body portion 6 to the shoulder portion 5 of the outer bottle 2. At this time, the ridge line 12a of the quadrangular pyramid portion 12 of the shoulder portion 5 in the outer bottle 2 is on the extension of the ridge line 15a of the quadrangular pyramid portion 15 of the bottom portion 7. Therefore, the valley bending deformation in the inner container body 18 proceeds toward the side surface portion 18b corresponding to the portion sandwiched between the ridge lines 12a and 12a of the quadrangular pyramid portion 12 of the shoulder portion 5.

Further, at this time, the portion of the inner container body 18 corresponding to the ridge line 12a of the quadrangular pyramid portion 12 of the shoulder portion 5 acts as a rib in the same manner as the portion corresponding to the ridge line 15a of the quadrangular pyramid portion 15 of the bottom portion 7. Therefore, the strength is higher than that of the side surface portion 18b corresponding to the portion sandwiched between the ridge lines 12a and 12a. Therefore, as shown in FIG. 6B, the side surface portion 18b corresponding to the portion sandwiched between the ridge lines 12a and 12a is easily valley-folded and the valley-folded portion 18a is formed in a form continuous with the valley-folding deformation, and the adjacent side surface portions 18a are formed. 18b and 18b come into contact with each other and are deformed in a cross-sectional view.

Further, at this time, as described above, the inner container body 18 is provided with the deformation guide portion 24 having a bending habit to form the valley fold portion 18a, so that the inner container body 18 corresponds to the portion sandwiched between the ridge lines 12a and 12a. The side surface portion 18b to be formed can more easily and surely form the valley fold portion 18a by being guided by the fold habit of the deformation guide portion 24.

As a result, the valley bending deformation occurs in the entire inner container body 18 from the outside to the inside in the width direction, and the quadrangular pyramid portion of the bottom 7 of the outer bottle 2 in the length direction. It will proceed from the portion corresponding to 15 toward the inner opening portion 17, and the contents contained in the inner container body 18 can be completely poured out, and the amount of residual liquid can be reduced. can.

Further, since the synthetic resin multiple bottle 1 of the present embodiment includes the recess 8 having the shape of the quadrangular pyramid trapezoidal recesses 8a, 8b, 8c, the inner container body 18 can be formed by heat crimping during blow molding. It is in close contact with the outer bottle 2. Further, the recess 8 is composed of quadrangular pyramid trapezoidal recesses 8a, 8b, 8c, and is provided with a large number of stepped portions and bent portions. No outside air invades.

Therefore, while the valley fold portion 18a is formed along the length direction of the outer bottle 2, the inner container body 18 is housed in the inner container body 18 without peeling from the outer bottle 2 in the recess 8. It is possible to more reliably and thoroughly pour out the contents, and it is possible to more reliably reduce the amount of residual liquid.

In the present embodiment, the portion of the outer bottle 2 that is connected to the outer mouth portion 4 of the shoulder portion 5 is a quadrangular pyramid portion 12, but the entire shoulder portion 5 may be a quadrangular pyramid portion 12. Further, in the present embodiment, the portion of the outer bottle 2 that is connected to the ground contact portion 9 of the bottom portion 7 is a quadrangular pyramid-shaped portion 15, but the entire bottom portion 7 may be a quadrangular pyramid-shaped portion 15.

Further, in the present embodiment, the quadrangular pyramid portions 12 and 15 of the outer bottle 2 have a quadrangular pyramid shape having a quadrangular cross section orthogonal to the axis, but the quadrangular pyramid portions 12 and 15 have a cross section orthogonal to the axis. It may be any one of a triangular pyramid having a triangular shape, a pentagonal pyramid having a pentagonal shape, and a hexagonal pyramid having a hexagonal shape. Further, in the polygonal pyramid shape, the vertices of the polygon may be cut, or the vertices of the polygon may be marked with an R, and the side sandwiched between the vertices may be bulged outward. , One or more vertices may be provided on the bulged side.

Further, in the present embodiment, the body portion 6 of the outer bottle 2 is gradually reduced in diameter from the lower end portion of the step portion 6a connected to the shoulder portion 5 toward the central portion 6c, and the step portion connected to the bottom portion 7 from the central portion 6c. Although the body portion 6 has a drum shape that gradually increases in diameter toward the upper end portion of 6b, the body portion 6 may have a cylindrical shape having the same diameter from the lower end portion of the step portion 6a to the upper end portion of the step portion 6b.

Further, in the present embodiment, the outer peripheral surface of the outer opening portion 4 is provided with the male threaded portion 10, but the outer opening portion 4 may be a simple cylindrical shape without the male threaded portion 10, and is to be used in this way. Therefore, for example, it can be applied to a plug-type mouth portion of a soy sauce bottle or the like.

Further, in the present embodiment, when the deformation guide portion 24 is formed, a valley-folded portion 18a having a cross-shaped cross section is formed on the inner container body body 18 as shown in FIG. 4B. However, the deformation guide portion 24 may have a function of guiding the valley fold deformation, and it is not necessary to form the valley fold portion 18a having a cross-shaped cross section.

That is, in the process shown in FIG. 4B, instead of the perfect cross-sectional cross-shaped valley fold 18a shown by the solid line in FIG. 6A, the incomplete cross-sectional cross-sectional (star-shaped) valley fold shown by the virtual line in FIG. It may be limited to the extent that the portion 18a is formed.

Further, in the present embodiment, a step of peeling the inner container body 18 of the synthetic resin multiple bottle 40 from the outer bottle 2 to reduce and deform the volume, and a step of returning the inner container body 18 to its original shape to form the deformation guide portion 24. Although the above steps are performed in the mold 33, each of the steps may be performed on the synthetic resin multiplex bottle 40 taken out from the mold 33. However, when the synthetic resin multiple bottle 40 is taken out from the mold 33, the shape of the mold or the like is formed on the outside of the outer bottle 2 so that the outer bottle 2 is not deformed to the outside when pressurized air is introduced from the ventilation path 23. It is preferable to provide a holder.

1 ... Synthetic resin multiple bottle, 2 ... Outer bottle, 3 ... Inner container, 4 ... Outer mouth, 5 ... Shoulder, 6 ... Body, 7 ... Bottom, 8 ... Frustum recess, 9 ... Grounding part , 17 ... Inner mouth, 18 ... Inner container body, 23 ... Ventilation path, 24 ... Deformation guide.

Claims (2)

A cylindrical outer mouth portion, a shoulder portion connected to the outer mouth portion, a body portion connected to the shoulder portion, a bottom portion connected to the body portion, and a ground contact portion connected to the bottom portion are provided to apply external pressure. On the other hand, the outer bottle that can be restored to its original shape, the cylindrical inner mouth portion that is arranged on the inner peripheral side of the cylindrical outer mouth portion of the outer outer bottle, and the inner surface shape of the outer outer bottle that is connected to the inner mouth portion. An inner container body having a shape along the shape is provided, and an inner container body that is deformed by external pressure is formed between the outer mouth portion and the inner mouth portion to allow outside air to flow between the outer bottle and the inner container body. A method for manufacturing a synthetic resin multiple bottle, which is provided with a ventilation path to be introduced, and the inner container body is provided with a deformation guide portion for guiding deformation due to external pressure.
A synthetic resin in which the inner preform forming the inner container is arranged on the inner peripheral side of the outer preform forming the outer bottle, and the inner container is arranged on the inner peripheral side of the outer bottle by blow molding. The process of forming multiple bottles made of plastic
A pressurized gas is introduced between the outer bottle and the inner container body from the air passage while maintaining at least the inner container body at a temperature equal to or higher than the glass transition temperature of the resin constituting the inner container body. Or, by depressurizing the inside of the inner container body, the inner container body is peeled off from the outer bottle and deformed.
While the inner container body is maintained at a temperature lower than the glass transition temperature of the resin constituting the inner container body, the space between the outer bottle and the inner container body main body is depressurized through the ventilation passage. Alternatively, a step of returning the inner container body to its original shape by introducing a pressurized gas into the inner container body and forming the deformation guide portion as a trace of the deformation on the inner container body. A method for manufacturing a multi-layered bottle made of synthetic resin, which is characterized by being provided. The method for producing a synthetic resin multiple bottle according to claim 1 , wherein both the outer bottle and the inner container are made of polyester resin.

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