JP2019123510A - Synthetic resin blow molding compound bottle and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blow-molded multi-bottle made of a synthetic resin which can be manufactured by an apparatus having a simple structure and can surely prevent peeling of an inner container body from an outer shell bottle at the bottom of the bottle. .. SOLUTION: A blow-molded multi-bottle 1 made of synthetic resin is provided with an outer shell portion 4, a shoulder portion 5, a body portion 6 and a bottom portion 7 having a recess 8, and is an outer shell bottle 2 capable of returning to the original shape with respect to external pressure. , The inner container body 3 which is connected to the cylindrical inner mouth portion 13 and has an inner container body body 14 having a shape along the inner surface shape of the outer shell bottle 2, and which is deformed by external pressure, and the outer mouth portion 4 and the inner mouth. A ventilation passage 19 formed between the outer shell bottle 2 and the inner container body 3 to introduce outside air is provided between the outer shell bottle 2 and the inner container body 3. The bottom surface of the concave portion 8 is provided with an outer convex portion 9a protruding outward, and the bottom portion of the inner container body 14 is provided with an inner convex portion 9b protruding outward along the outer convex portion 9a. The portion 9b is in close contact with the inner surface of the outer convex portion 9a. [Selection diagram] FIG. 5

Description

  The present invention relates to a synthetic resin blow-molded multiple bottle and a method of manufacturing the same.

  Conventionally, an inner container body which is deformed by external pressure and reduced in volume (hereinafter sometimes referred to as “volume reduction deformation”) is disposed inside the outer shell bottle which can be returned to its original shape with respect to external pressure, A blow molded multi-bottle is known in which external air is introduced into the container body. The blow molded multiple bottle is manufactured, for example, by forming an inner preform and an outer preform by injection molding of a polyester resin, and blow molding in a state where the inner preform is disposed on the inner peripheral side of the outer preform. .

  When the blow molded multi-bottle is subjected to volume reduction deformation of the inner container body by pressing the barrel portion of the outer shell bottle and pouring out the contents contained in the inner container body, the pressure is released. Outside air is introduced between the shell bottle and the inner container body by the action of a separately provided check valve or the like. As a result, while the shell bottle is returned to its original shape by the external pressure, the inner container body is maintained in a state of reduced volume deformation. In this case, since the outside air does not intrude into the inner container body, it is possible to prevent the contents contained in the inner container body from being deteriorated due to oxidation or the like.

  By the way, when the inner container body is peeled off from the outer shell bottle at the bottom of the bottle when the inner container body is reduced in volume as described above, the blow molded multi-bottle is difficult to achieve the expected volume reduction deformation. And there is a problem that it may not be possible to pour out the contents sufficiently.

  In order to solve the above-mentioned problem, a blow molded multiple bottle is also known which is provided with a holding rib for holding the inner container body by the outer shell bottle and holding the inner container body integrally at the bottom of the bottle (see, for example, Patent Document 1) .

  In addition, a recess having a plurality of polygonal frustum-shaped steps is formed in the bottom of the bottle, and this recess suppresses the entry of air into the portion of the bottom between the inner container body and the shell bottle, and the bottle bottom The applicant of the present invention has also proposed an apparatus in which the inner container body is not peeled off from the outer shell bottle in (see, for example, Patent Document 2).

JP, 2013-245010, A JP, 2017-171317, A

  In the conventional synthetic resin blow molded multiple bottle, an external force needs to be applied to the holding rib in order to form a configuration in which the outer container bottle sandwiches the inner container body. The external force is applied, for example, by a pin projecting from a pinch-off portion of a mold when blow molding, but when doing so, the configuration of an apparatus used for producing the synthetic resin blow molded multiple bottle becomes complicated. There is a disadvantage.

  On the other hand, as proposed by the present applicant, if a recess having a plurality of steps is provided at the bottom, peeling of the inner container body at the bottom of the bottle can be prevented during normal use.

  Here, before the synthetic resin blow molded multiple bottle is distributed to the general market, it is checked whether or not the inner container body has a pinhole in the multiple bottle manufacturing process, and the inner container body is peeled off from the outer shell bottle It is preferable to conduct a quality inspection as to whether or not the contents can be sufficiently poured out without easily peeling the inner container body from the shell bottle at the bottom of the bottle in the process of volume reduction and deformation.

  In this quality inspection, external air is introduced between the shell bottle and the inner container body to peel off the inner container body from the shell bottle and reduce its volume, and then the inner container body is returned to the original shape. It is conceivable to carry out in the process of

  When performing such an operation process in quality inspection, when external air is put between the shell bottle and the inner container body, the external force stronger than the pressing force when a normal user presses the shell bottle is contents There is a possibility that it will be added to the container body, and it is required to further improve the adhesion between the shell bottle and the inner container body at the bottom of the bottle in the multiple bottle.

  In addition, even when the user applies a strong external force to the inner container body by an unexpected strong pressing force, the outer shell bottle and the inner container body are in close contact with each other without peeling at the bottom of the bottle. preferable.

  In view of the above points, the present invention can be manufactured by an apparatus having a simple structure, and can further improve the adhesion between the shell bottle and the inner container body at the bottom of the bottle. Intended to provide.

[1] In order to achieve the above object, the present invention is
A cylindrical outer opening, a shoulder connected to the outer opening, a body connected to the shoulder, and a bottom connected to the body and having a recess extending into the bottle And a shell bottle that can be returned to its original shape under external pressure,
A cylindrical inner opening disposed on the inner peripheral side of the outer opening of the outer shell bottle, and an inner container body connected to the inner opening so as to conform to the inner surface of the outer shell bottle; An inner container body that is deformed by external pressure,
An air passage formed between the outer opening and the inner opening to introduce outside air between the outer shell bottle and the inner container body;
Blow molding of synthetic resin formed by blow molding in a mold in a state where a bottomed cylindrical inner preform serving as the base of the inner container body is attached to an outer preform serving as the base of the outer shell bottle Multiple bottles,
The bottom surface of the concave portion is provided with an outer convex portion that protrudes outward,
The bottom portion of the inner container body is provided with an inner convex portion that protrudes outward along the outer convex portion,
The inner convex portion is in close contact with the inner surface of the outer convex portion.

  When performing a quality inspection such as adhesion between a recess on the bottom surface of the pinhole and the bottom of the bottle, and the inner container body in the blow molding multiple bottle made of synthetic resin, first, the air flow is performed between the outer shell bottle and the inner container body. Outside air is introduced from the road, and the inside container body is reduced in volume and deformed by the outside pressure. Then, after the inner container body is deflated, external air is introduced into the inner container body to expand the inner container body and restore the shape along the inner surface of the outer shell bottle.

  Here, in the blow molding multiple bottle made of synthetic resin of the present invention, an outer convex portion protruding outward is provided on the bottom surface of the recess provided in the bottom portion. In the concave portion provided with the outer convex portion, the inner preform is thermocompression-bonded to the outer preform at the time of blow molding, and the inner container body is closely attached to the outer shell bottle in the concave portion. An inner convex portion having a shape that follows the inner surface shape of the convex portion is formed.

  As described above, the concave portion has the inner container body in close contact with the outer shell bottle, and has an outer convex portion projecting outward on the bottom surface. Since the inner convex portion is in close contact with the outer convex portion between the outer convex portion and the inner convex portion protruding outward from the bottom surface of the concave portion, the outside air introduced from the air passage is particularly in the concave portion. It is difficult to intrude, and peeling of the inner container body from the shell bottle can be reliably prevented. Thus, in the multi-bottle of the present invention, the inner container body is an outer shell at the bottom of the bottle even in the quality inspection where a relatively strong external pressure may be applied or when an unexpected strong external force is applied by the user. The state in close contact with the bottle can be maintained, and the contents inside the inner container can be sufficiently drained.

  The synthetic resin blow-molded multiple bottle according to the present invention comprises an outer preform and an inner preform disposed on the inner peripheral side of the outer preform, using a mold for imparting the shape to the recess. It is only necessary to blow mold the inner preform simultaneously and it can be easily manufactured.

  [2] Further, in the present invention, preferably, the recess is formed in a frustum shape of a plurality of steps, and at least the lowermost frustum shape is a polygonal frustum shape.

  As described above, the inner container body is in close contact with the outer shell bottle, and the concave portion is formed in a frustum shape having a plurality of steps, and at least the lowest level of the frustum shape is a polygonal frustum shape As a result, it has a shape including a stepped portion and a large number of bent portions formed of polygonal truncated pyramidal corners. For this reason, in the recess, external air introduced from the air passage is less likely to enter between the inner container body and the outer shell bottle, and the inner container body may be peeled off from the outer shell bottle. Furthermore, it can prevent reliably.

  [3] Further, in the blow molding multiple bottle made of synthetic resin of the present invention, it is preferable that the recess is formed in a multi-tiered pyramidal frustum shape.

  The concave portion can be provided with a plurality of stepped portions and a large number of bent portions formed by the corners of the polygonal frustum by being formed in a polygonal pyramidal shape having a plurality of steps, and the inner container in the concave portion during blow molding While the adhesion between the body and the shell bottle can be further improved, the external air introduced from the air passage can be more effectively prevented from invading between the inner container body and the shell bottle in the recess. Can.

  [4] Further, in the present invention, it is preferable to interpose a release agent between the body and the inner container body.

  It is preferable that the inner container body is in close contact with the recess and that the inner container body is easily peeled off from the body in order to reduce the volume. When a material mainly composed of polyethylene terephthalate resin is used as the material of the multiple bottle, etc., in the body of the stretch-blown multiple bottle, the adhesion with the inner container body is high and it is difficult to peel off and the volume is reduced It can be difficult. In such a case, it is preferable to interpose the release agent between the body of the shell bottle and the portion of the inner container body corresponding to the body. According to this configuration, the inner container body is in close contact with the recess, and the inner container body is easily peeled off from the trunk. For this reason, folding volume reduction deformation of the part corresponding to the trunk part of the inner container body is further facilitated.

  As the release agent, liquid paraffin, a silicon compound, and various other release agents can be used. In polyester resin, for example, multiple bottles based on polyethylene terephthalate, liquid paraffin is preferred.

[5] Further, the method for producing a blow molding multiple bottle made of synthetic resin of the present invention is
A cylindrical outer opening, a shoulder connected to the outer opening, a body connected to the shoulder, and a bottom connected to the body and having a recess extending into the bottle And a shell bottle that can be returned to its original shape under external pressure,
A cylindrical inner opening disposed on the inner peripheral side of the outer opening of the outer shell bottle, and an inner container body connected to the inner opening so as to conform to the inner surface of the outer shell bottle; And an inner container body that is deformed by an external pressure,
An air passage formed between the outer opening and the inner opening to introduce outside air between the outer shell bottle and the inner container body;
The bottom surface of the concave portion is provided with an outer convex portion that protrudes outward,
The bottom portion of the inner container body is provided with an inner convex portion that protrudes outward along the outer convex portion,
The inner convex portion is a method for producing a synthetic resin blow-molded multiple bottle in close contact with the inner surface of the outer convex portion,
When blow molding, the outer shell is inserted with the bottomed cylindrical inner preform serving as the base of the inner container body inserted into the bottomed cylindrical outer preform serving as the base of the outer shell bottle. A mold release agent is interposed between the reform and the inner preform, and the bottom of the inner preform is pressed by a rod having a tip having the same shape as the inner surface of the inner convex portion in a mold for a shell bottle , And is formed by blow molding.

  According to the manufacturing method of the present invention, by interposing a mold release agent between the outer preform and the inner preform, the side of the shell bottle is pressed to press the contents in the inner container body to the inner opening. When discharging from the part, the inner container body main body easily peels off from the inner surface of the outer shell bottle except for the concave portion, and the contents can be easily taken out.

  In addition, since the tip of the rod for extending the outer preform and the inner preform has the same shape as the inner surface of the inner convex portion, even if a release agent is contained between the outer convex portion and the inner convex portion, the other It is pushed out to a portion, and the release agent can be absent or extremely small between the outer convex portion and the inner convex portion, and the outer convex portion and the inner convex portion do not easily separate. As a result, it is further difficult for external air to enter between the outer convex portion and the inner convex portion, and the inner container body can be further reliably prevented from peeling off from the bottom surface of the outer shell bottle.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows the synthetic resin blow molding multiple bottle of embodiment of this invention. Sectional drawing which shows the state cut | disconnected by the II-II line of FIG. Sectional drawing which shows the state which has arrange | positioned the inner preform used for manufacture of synthetic resin blow molding multiple bottles of this embodiment in an outer preform. FIG. 4A is a schematic sectional view showing an initial step of the method for producing a synthetic resin blow molded multiple bottle according to this embodiment, FIG. 4B is a schematic sectional view showing a blow molding step, and FIG. 4C is an end step of the blow molding step Typical sectional drawing shown. Sectional drawing which expands and shows the bottom part of synthetic resin blow molding multiple bottles of this embodiment. Explanatory drawing which expands and shows the bottom part of the synthetic resin multiple bottle of a comparative example.

  An embodiment of a synthetic resin blow-molded multiple bottle of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 and 2, the blow molding multiple bottle 1 made of synthetic resin of the present embodiment is housed inside the outer shell bottle 2 which can be returned to its original shape against the external pressure, and is reduced by the external pressure. The inner container body 3 is deformed.

  The outer shell bottle 2 has, for example, a cylindrical outer opening 4, a quadrangular pyramidal shoulder 5 connected to the outer opening 4, a square cylindrical trunk 6 connected to the shoulder 5, and a trunk And a square pyramidal bottom portion 7 connected to 6. The outer opening 4 is provided with a male screw 10 and a support ring 11 on the outer peripheral surface, and the bottom 7 is a lower end grounding portion 7b and a recess 8 which bulges inside the outer shell bottle 2 to give the multiple bottle 1 self-supporting property. And have. A mold release agent intervenes between at least the body 6 and the inner container body 14 corresponding to the body 6.

  As shown in an enlarged manner in FIG. 5, the recess 8 has a shape in which a plurality of multi-pyramidal frustum-shaped recesses are stacked, and, for example, the first multi-pyramidal frustum-shaped recess 8 a and the first multi-pyramidal frustum-shaped recess 8 a A smaller second polygonal frustum-shaped recess 8b stacked on the inner peripheral side and a smaller third polygonal frustum-shaped recess 8c stacked on the inner peripheral side of the second polygonal frustum-shaped recess 8b are provided.

  At the center of the third polygonal frustum-shaped concave portion 8c, a bottomed cylindrical outer convex portion 9a protruding toward the outside of the outer shell bottle 2 is provided. The inner container body 14 is provided with a bottomed cylindrical inner convex portion 9b along the inner surface of the outer convex portion 9a.

  In FIG. 5, the inner container body 14 has a shape corresponding to the inner surface of the outer shell bottle 2 as indicated by a dotted line, except for a portion corresponding to the recess 8 as indicated by a solid line. It shows a state in which it is peeled off from the shell bottle 2 and reduced in volume so that the side surface of the inner container body 14 is inclined in a longitudinal sectional view.

  The shoulder 5 and the bottom 7 are rounded at the top of the square, and have ridges 5a and 7a at the top. Here, the ridgeline 7a is formed at the same position in the circumferential direction of the shell bottle 2 corresponding to the ridgeline 5a.

  On the other hand, the inner container body 3 is connected to the cylindrical inner port 13 and the inner port 13 disposed on the inner peripheral side of the outer port 4, and the shoulder 5 and the body 6 of the outer shell bottle 2 And an inner container body 14 having a shape that conforms to the inner surface shape of the bottom 7 and the recess 8. The inner opening 13 includes an extension 15 extending upward from the upper end of the outer opening 4 at an upper portion, and a collar 16 protruding radially outward from the extension 15. The upper end edge of the outer opening 4 is locked by the portion 16.

  Further, the inner opening 13 is provided with a groove 17 on the outer peripheral surface. A groove 18 connected to the groove 17 is formed on the lower surface of the collar portion 16, and the groove 18 is opened to the outside at the outer peripheral edge of the collar portion 16. As a result, the groove 17 and the groove 18 form an air passage 19 for introducing the outside air between the outer shell bottle 2 and the inner container body 3.

  In the inner container body 14, a bottomed cylindrical inner convex portion 9 b is formed along the inner surface shape of the outer convex portion 9 a at a portion that follows the inner surface shape of the concave portion 8 b.

  The multiple bottle 1 can be manufactured, for example, by arranging the inner preform 21 inside the outer preform 22 and simultaneously blow-molding it, as shown in FIG.

  The inner preform 21 is formed by injection molding using a polyester resin such as polyethylene terephthalate as a material, the inner opening 13 and a bottomed cylindrical member connected below the inner opening 13 and having an outer diameter smaller than the inner opening 13. And the inner body portion 23 of the The inner opening portion 13 has the same shape as the inner opening portion 13 of the inner container body 3, the same reference numerals are given to the same configurations, and the detailed description will be omitted. Since the outer diameter of the inner body portion 23 is smaller than that of the inner opening portion 13, the lower end of the groove 17 is exposed to the outer surface of the inner body portion 23 at the boundary between the inner opening portion 13 and the inner body portion 23.

  The outer preform 22 is formed by injection molding using a polyester resin such as polyethylene terephthalate as a material, and is formed by the outer opening 4 and a bottomed cylindrical outer body 24 continuously provided below the outer opening 4. Be done. The outer opening 4 has the same shape as the outer opening 4 of the shell bottle 2, and the same reference numerals are given to the same components and the detailed description will be omitted.

  The inner opening portion 13 of the inner preform 21 is inserted into and attached to the outer opening portion 4 of the outer preform 22, and the inner body portion 23 of the inner preform 21 is disposed inside the outer body portion 24 of the outer preform 22. At this time, the extension 15 extends above the outer opening 4 of the outer preform 22, and the hook 16 abuts on the upper end surface of the outer opening 4 of the outer preform 22 and is locked. Thereby, the inner opening 13 of the inner preform 21 is reliably positioned inside the outer opening 4 of the outer preform 22.

  Next, blow molding of the multiple bottle 1 of the present embodiment will be described with reference to FIGS. 4A to 4C.

  The blow molding apparatus used in the present embodiment is well known, and includes a mold 31, a blow nozzle 32, and a stretch rod 33, as shown in FIGS. 4A to 4C. The tip shape of the stretch rod 33 is formed in a cylindrical shape along the inner surface shape of the inner convex portion 9 b. By making the tip shape of the stretch rod 33 cylindrical, even if the release agent unintentionally enters between the outer convex portion 9a and the inner convex portion 9b formed in a cylindrical shape with a bottom, it extrudes strongly It can be attached closely.

  The mold 31 has a molded portion 34 shaped to conform to the outer surface shape of the shoulder 5, the body 6 and the bottom portion 7 of the outer shell bottle 2, a concave molded portion 35 shaped to conform to the outer surface shape of the concave portion 8, and an outer preform And 22 a support opening 36 for exposing and supporting the upper part of the support ring 11 of the outer opening 4. In the recess forming portion 35, an outer protrusion forming portion 35a having a shape that conforms to the outer surface shape of the outer protrusion 9a is formed. The mold 31 has a split mold structure (not shown), and the multiple bottle 1 after molding can be taken out of the mold by dividing it on the left and right sides of the molding part 34 and the bottom molding part 35 side.

  The blow nozzle 32 is raised and lowered by raising and lowering means (not shown), and airtightly abuts on the upper end surface of the collar portion 16 of the inner preform 21 through the O-ring 37. A stretch rod 33 is inserted through the blow nozzle 32, and a gas passage 38 connected to high pressure gas supply means (not shown) is formed between the outer circumferential surface of the stretch rod 33 and the inner circumferential surface of the blow nozzle 32. .

  The stretch rod 33 is advanced at the time of blow molding by an advancing and retracting drive means (not shown). In FIG. 4A, the stretch rod 33 protrudes from the tip of the blow nozzle 32. However, when the stretch rod 33 is not in use, the stretch rod 33 is retracted and accommodated inside the blow nozzle 32 (upper in the figure).

  When the multi-bottle 1 is manufactured by the blow molding device having the above-described configuration, as shown in FIG. 4A, the inner preform 21 is inserted into the outer preform 22, and the space between the inner preform 21 and the outer preform 22 is attached. The mold release agent is applied to a portion (a side surface excluding the hemispherical bottom surfaces of the inner preform 21 and the outer preform 22) excluding the portion to be the concave portion 8 after blow molding. By applying the release agent in this manner, the release agent can be made difficult to enter between the recess 8 and the inner container body 14 after blow molding, and the inner container body 14 is appropriately crimped to the recess 8 be able to.

  Then, after the outer preform 22 is set in the mold 31, the blow nozzle 32 is connected to the inner opening 13 of the inner preform 21. The inner preform 21 and the outer preform 22 are heated to a blowable temperature prior to being set in the mold 31.

  Next, as shown in FIG. 4B, pressurized air is introduced into the inner preform 21 from the gas passage 38 of the blow nozzle 32, and at the same time, the stretch rod 33 is advanced downward. As a result, the inner preform 21 expands and adheres to the inner surface of the unexpanded outer preform 22.

  Subsequently, when the stretch rod 33 is advanced downward while further introducing pressurized air into the inner preform 21 from the state shown in FIG. 4B, the outer preform is formed by the inner body portion 23 of the expanded inner preform 21. The outer body portion 24 of 22 is spread and shaped into the shape of the shoulder portion 5, the body portion 6 and the bottom portion 7 of the outer shell bottle 2 by the forming portion 34 of the mold 31 as shown in FIG. Is formed into the shape of the recess 12.

  In addition, the tip of the stretch rod 33 is inserted into the outer convex portion molding portion 35a to form an outer convex portion 9a and an inner convex portion 9b. At this time, since the inner convex portion 9b presses the outer convex portion 9a against the outer convex portion molding portion 35a at the tip of the stretch rod 33, a release agent is unintentionally interposed between the outer convex portion 9a and the inner convex portion 9b. Even in the case of being intruded, the outer convex portion 9a and the inner convex portion 9b can be strongly adhered to each other so as not to be easily peeled off by being pushed away from between the outer convex portion 9a and the inner convex portion 9b.

  Further, the inner body portion 23 of the inner preform 21 is formed into a shape that conforms to the inner surface shape of the shoulder portion 5, the body portion 6, the bottom portion 7 and the recess 8 of the outer shell bottle 2. As a result, the multiple bottle 1 shown in FIGS. 1 and 2 is obtained.

  In the multiple bottle 1, when the recess 8 is formed by the blow molding, the inner preform body 21 is brought into close contact with the outer shell bottle 2 by thermocompression bonding of the inner preform 21 to the outer preform 22.

  In the multiple bottle 1 of the present embodiment, the contents not shown are accommodated in the inner container body 3 in the use state, and when the contents are poured out, the outer opening 4 and the inner opening 13 face downward. I cant. Then, when the body portion 6 of the outer shell bottle 2 is pressed, the portion corresponding to the concave portion 8 of the outer shell bottle 2 of the inner container body 14 is integrated with the concave portion 8 of the outer shell bottle 2 and tightly fixed. The content of the inner container body 14 is poured out by peeling off the outer shell bottle 2 from the outer shell bottle 2 in a region of the inner container body 14 corresponding to the outer opening 4 to the lower end grounding portion 7b. In the multiple bottle 1, since the body 6 is cylindrical, any portion in the circumferential direction may be pressed, and the inner container body 14 can be reduced in volume and deformed.

  Next, when the pressing of the body portion 6 of the outer shell bottle 2 is released, the outside air is introduced from the air passage 19 between the outer shell bottle 2 and the inner container body 14 and the outer shell bottle 2 is in its original shape Although the inner container body 14 is restored, the inner container body 14 is maintained in the state of reduced volume deformation.

  At this time, the contents are concentrated in the direction of the inner opening 13 by gravity, and the inner container body 14 is from the portion corresponding to the barrel 6 of the outer shell bottle 2 to the ridgelines 5a and 5a of the inner container body 14 , 7a and 7a are formed at the central portion of the side surface portion corresponding to the portion sandwiched by the portions 7a and 7a, so that the valley bending deformation is started by immersing inward.

  In the multiple bottle 1, the content is gradually decreased by repeating the pressing of the body portion 6 of the outer shell bottle 2 and the release of the pressing. When the content decreases, the valley-bending deformation of the inner container body 14 further progresses, and the adjacent side portions come in contact with each other to be folded and deformed in a cross-sectional view.

  As described above, when the valley-folded portion is formed, in the multiple bottle 1, since the concave portion 8 has a shape including the polygonal frustum-shaped concave portions 8a, 8b, and 8c, the content is obtained by heat pressure bonding during blow molding. The container body 14 is in close contact with the shell bottle 2. Further, the concave portion 8 is composed of the polygonal frustum-shaped concave portions 8a, 8b and 8c, and is provided with a large number of stepped portions and bent portions, so that the outer shell bottle 2 and the inner container body main body in normal use There is no intrusion of external air between the fourteen.

  Therefore, while the valley folds are formed along the length direction of the shell bottle 2, the inner container body 14 does not peel off from the shell bottle 2 in the recess 8 and is accommodated in the inner container body 14 It is possible to pour out without overflowing the contents which are being carried out, and to reduce the residual liquid.

  Further, in the synthetic resin blow-molded multiple bottle 1 of the present embodiment, the outer convex portion 9 a protruding outward is provided on the bottom surface of the concave portion 8 provided in the bottom portion 7. The inner preform 21 is thermocompression-bonded to the outer preform 22 at the time of blow molding, and the inner container body 3 is in close contact with the outer shell bottle 2 in the recess 8 in the blow molding. . Thus, the outside air introduced from the air passage 19 is less likely to intrude between the inner container body 3 and the outer shell bottle 2.

  Further, as described above, the concave portion 8 has the inner container body 3 in close contact with the outer shell bottle 2 and, at the bottom surface, the outer convex portion 9a protruding outward. An inner convex portion 9b having a shape conforming to the inner surface shape of the outer convex portion 9a is in close contact with the outer convex portion 9a protruding outward from the bottom surface of the concave portion 8, and is positioned on the bottom surface of the concave portion In particular, it is difficult for outside air to intrude between the outer convex portion 9a and the inner convex portion 9b which protrude in the direction opposite to the direction of the recess 8.

  As a result, the inner container body 14 of the outer bottle 2 is not only used during normal use in which the outer shell bottle 2 is pressed by the user's hand, but also during various quality inspections such as pinhole inspection of the inner container body 14. Under a situation where a relatively strong external force is applied to the inner container body 14 as in the step of peeling it off from the body 6 and returning it later, or when an unexpected external force is applied to the outer shell bottle 2 or the like. Even if it does, it can prevent reliably that the inner container body 3 peels from the recessed part 8 of the shell bottle 2.

  The synthetic resin blow-molded multiple bottle is simultaneously blow-molded in a state where the inner preform is disposed on the inner peripheral side of the outer preform, using a mold for giving the shape to the recess. Just good, can be easily manufactured.

  Further, in the present embodiment, the recess 8 has a shape in which frustum-shaped recesses 8a to 8c are stacked in a plurality of stages, and at least the lowermost step of the frustum-shaped recess 8a has a polygonal frustum shape.

  As described above, the inner container 3 is in close contact with the outer shell bottle 2 as described above, and the frustum-like concave portions 8a to 8c are stacked in a plurality of stages, and therefore, the concave portion 8 has many stepped portions. Since it has a polygonal pyramidal frustum shape, it has a shape provided with a large number of bends. Therefore, in the recess 8, the outside air introduced from the air passage 19 is less likely to intrude between the inner container body 3 and the outer shell bottle 2, and the inner container body 3 peels from the outer shell bottle 2. Furthermore, it can prevent reliably.

  Further, in the blow molding multiple bottle 1 made of a synthetic resin of the present embodiment, the recess 8 is provided with a plurality of stages of polygonal pyramidal frustum shaped recesses 8 a to 8 c.

  The concave portion 8 can be provided with a plurality of stepped portions and bent portions by being provided with a plurality of steps of polygonal frustum-shaped concave portions 8a to 8c, and when the blow molding is performed, the inner container body 3 and the outer shell bottle 2 While adhesion can be improved, external air introduced from the air passage 19 can be more effectively prevented from invading between the inner container body 3 and the outer shell bottle 2. Then, the pinhole inspection of the inner container body main body 14 to which a relatively strong external pressure may be applied in the quality control process of the multiple bottle 1, etc. remains in close contact without peeling the outer convex portion 9a and the inner convex portion 9b. It can be carried out. For this reason, rationalization and simplification of the manufacturing process of the multiple bottle 1 including the quality inspection process and the fold forming process of the inner container body 14 can be achieved.

  According to the method of manufacturing the blow molding multiple bottle 1 made of synthetic resin of the present embodiment, the mold is released between the body parts of the outer preform 22 and the inner preform 21 (in the part excluding the part forming the recess 8), When the side of the shell bottle 2 is pressed by applying an agent and manufactured by blow molding and the contents in the inner container body 14 are discharged from the inner opening, the inner container is removed except for the recess 8 The body 14 easily peels off the inner surface of the shell bottle 2 and the contents can be easily removed.

  As a mold release agent, liquid paraffin can be used, for example. The release agent is a thin layer and is interposed between the cylindrical preforms of the inner preform 21 and the outer preform 22, and between the recess 8 after blow molding and the inner container body 14 corresponding to the recess 8. It is preferred to apply so as not to be present.

  In addition, since the tip of the stretch rod 33 which stretches the outer preform 22 and the inner preform 21 has a shape that conforms to the inner surface shape of the inner convex portion 9 b, the mold release between the outer convex portion 9 a and the inner convex portion 9 b The agent is pushed out to the other part except between the outer convex portion 9a and the inner convex portion 9b, and substantially no mold release agent exists between the outer convex portion 9a and the inner convex portion 9b It becomes difficult to separate the portion 9a and the inner convex portion 9b. As a result, the outside air is further less likely to enter between the outer convex portion 9a and the inner convex portion 9b, and peeling of the inner container body 14 from the bottom of the outer shell bottle 2 can be further reliably prevented.

  FIGS. 6A and 6B show, as a comparative example, the concave portion 8 when a pinhole inspection of the inner container body 14 is performed by applying a relatively strong external pressure without forming the outer convex portion 9 a and the inner convex portion 9 b. It is sectional drawing which shows a peeling state typically. As shown in FIG. 6, when the inner container body 14 is peeled off from the body 6 by a relatively strong external force without the outer convex portion 9 a and the inner convex portion 9 b, the inner container body closely attached to the concave portion 8. There is a possibility that the main body 14 may be separated from the recess 8.

  In the present embodiment, the recess 8 has a three-stage configuration including the first to third three polygonal pyramidal recesses 8a, 8b and 8c, but the recess 8 may have a truncated cone shape. It may be a polygonal frustum shape, and in the case of a polygonal frustum shape, at least the lowermost frustum-like recess 8a is preferably a polygonal frustum shape, and the other steps may be a polygonal frustum shape. It may be frusto-conical. Moreover, the recessed part 8 should just be equipped with multiple steps of polygonal frustum-shaped recessed part, and is not limited to the said three-step structure.

  Further, the outer convex portion 9a and the inner convex portion 9b are not limited to the cylindrical shape, and may be a polygonal shape or a frustum shape.

  Further, in the present embodiment, the shoulder 5 and the bottom 7 of the shell bottle 2 have a quadrangular pyramid shape, but the shoulder 5 and the bottom 7 have a triangular pyramid shape, a pentagon pyramid shape, or a hexagonal pyramid shape. It may be pyramidal.

  In addition, in the polygonal pyramid shape or the polygonal cylinder shape, the apex of the polygon may be cut or R may be attached to the apex of the polygon. Furthermore, the side between the apexes may be bulged outward, and one or more apexes may be provided on the bulged sides.

  Furthermore, in the multiple bottle 1, the outer shell bottle 2 can be returned to its original shape with respect to the external pressure, and the inner container body 3 may be deformed by the external pressure. The shape of the bottom portion 7 is not limited to the above-described shape, and may be any shape.

  Further, in the present embodiment, the male screw portion 10 is provided on the outer peripheral surface of the outer opening 4. However, the outer hole 4 may have a simple cylindrical shape without the male screw 10. Thus, it can be applied to, for example, a stopper type opening such as a soy sauce bottle.

DESCRIPTION OF SYMBOLS 1 synthetic resin blow molding multiple bottle 2 outer shell bottle 3 inner container body 4 outer opening 5 shoulder 5 a ridge line 6 body 7 bottom 7 a ridge line 7 b lower end grounding portion 8 concave portion 8 a first polygonal frustum concave portion 8 b second Pyramidal frustum-shaped recess 8c Third polygonal frustum-shaped recess 9a Outer convex portion 9b Inner convex portion 10 Male thread portion 11 Support ring 13 Inner port portion 14 Inner container body main body 15 Extension portion 16 Collar portion 17 Groove 18 Groove 19 Groove 19 Air passage 21 Inner preform 22 Outer preform 23 Inner body 24 Outer body 31 Mold 32 Blow nozzle 33 Stretching rod 34 Forming portion 35 Recess forming portion 35a Outer convex portion forming portion 36 Support opening 37 O ring 38 Gas passage 40 Release Agent

Claims (5)

A cylindrical outer opening, a shoulder connected to the outer opening, a body connected to the shoulder, and a bottom connected to the body and having a recess extending into the bottle And a shell bottle that can be returned to its original shape under external pressure,
A cylindrical inner opening disposed on the inner peripheral side of the outer opening of the outer shell bottle, and an inner container body connected to the inner opening so as to conform to the inner surface of the outer shell bottle; An inner container body that is deformed by external pressure,
An air passage formed between the outer opening and the inner opening to introduce outside air between the outer shell bottle and the inner container body;
Blow molding of synthetic resin formed by blow molding in a mold in a state where a bottomed cylindrical inner preform serving as the base of the inner container body is attached to an outer preform serving as the base of the outer shell bottle Multiple bottles,
The bottom surface of the concave portion is provided with an outer convex portion that protrudes outward,
The bottom portion of the inner container body is provided with an inner convex portion that protrudes outward along the outer convex portion,
The said inner convex part is closely_contact | adhered to the inner surface of the said outer convex part, The synthetic resin blow-molded multiple bottle characterized by the above-mentioned. A blow molding multiple bottle made of synthetic resin according to claim 1, wherein
The said recessed part is formed in the frustum shape of multiple steps | stages, and the lowest step of frustum-like shape is polygonal frustum shape characterized by the above-mentioned. A blow molding multiple bottle made of synthetic resin according to claim 1 or claim 2, wherein
The said recessed part is formed in multiple-step polygonal pyramid frustum shape, The synthetic resin blow-molded multiple bottle characterized by the above-mentioned. A blow molding multiple bottle made of a synthetic resin according to any one of claims 1 to 3,
A blow molding multiple bottle made of synthetic resin characterized in that a release agent is interposed between the body and the inner container body. A cylindrical outer opening, a shoulder connected to the outer opening, a body connected to the shoulder, and a bottom connected to the body and having a recess extending into the bottle And a shell bottle that can be returned to its original shape under external pressure,
A cylindrical inner opening disposed on the inner peripheral side of the outer opening of the outer shell bottle, and an inner container body connected to the inner opening so as to conform to the inner surface of the outer shell bottle; And an inner container body that is deformed by an external pressure,
An air passage formed between the outer opening and the inner opening to introduce outside air between the outer shell bottle and the inner container body;
The bottom surface of the concave portion is provided with an outer convex portion that protrudes outward,
The bottom portion of the inner container body is provided with an inner convex portion that protrudes outward along the outer convex portion,
The inner convex portion is a method for producing a synthetic resin blow-molded multiple bottle in close contact with the inner surface of the outer convex portion,
When blow molding, the outer shell is inserted with the bottomed cylindrical inner preform serving as the base of the inner container body inserted into the bottomed cylindrical outer preform serving as the base of the outer shell bottle. A mold release agent is interposed between the reform and the inner preform, and the bottom of the inner preform is pressed by a rod having a tip having the same shape as the inner surface of the inner convex portion in a mold for a shell bottle A method of producing a blow molded multiple bottle made of synthetic resin, characterized by being formed by blow molding.