JP7282463B2 - Double container, preform assembly, preform assembly manufacturing method, and double container manufacturing method - Google Patents

Description

The present invention relates to a double container, a preform assembly, a method for manufacturing a preform assembly, and a method for manufacturing a double container.

A preform assembly in which an inner preform is incorporated inside an outer preform as a container for containing food seasonings such as soy sauce, beverages, cosmetics such as lotion, and toiletries such as shampoo, rinse, and liquid soap as liquid contents. is blow-molded to provide an outer layer body having a cylindrical outer mouth and a bottomed cylindrical body connected to the outer mouth via a shoulder, and an inner mouth disposed inside the outer mouth and an inner-layer body having a volume-reducing and deformable storage section which is detachably laminated on the inner surface of the shoulder section and the body section and which is connected to the inner mouth section. (See Patent Document 1, for example).

The double container is used, for example, as a squeeze-type pouring container combined with a pouring cap provided with a check valve, or as a pump-equipped container combined with a pump. In this case, by squeezing (squeezing) the body of the outer layer body or operating a pump, the liquid content can be poured out to the outside. and the inner layer body, only the outer layer body can be restored to its original shape while the containing portion of the inner layer body is reduced in volume and deformed. Therefore, according to the above-described double container, the content liquid stored in the storage portion of the inner layer body can be poured out to the outside without being replaced with the outside air. It is possible to reduce the contact of the outside air to the content liquid, and to suppress deterioration, deterioration, etc. of the content liquid.

JP 2017-178434 A

However, in a double container formed by blow-molding a preform assembly in which an inner preform is incorporated inside an outer preform, as in the conventional double container described above, there is a gap between the outer layer body and the inner layer body. If the outside air introduction port for introducing outside air is provided in the mouth portion composed of the outer mouth portion and the inner mouth portion, the airway from the outside air introduction port toward between the shoulder portion and the housing portion cannot be secured properly. , after the content liquid is poured out, outside air is not introduced between the body and the container through the shoulder and the container, and the volume reduction deformation of the container is not maintained, or the restoration of the outer layer body is hindered. There was a problem that there was a possibility that it would be lost.

The present invention has been made in view of such problems, and its object is to reliably secure an airway from an outside air inlet provided in the mouth toward between the body and the housing. An object of the present invention is to provide a double container, a preform assembly, a method for manufacturing the preform assembly, and a method for manufacturing the double container.

The double container of the present invention comprises an outer layer body having a cylindrical outer mouth and a bottomed cylindrical body connected to the outer mouth via a shoulder, a cylindrical inner mouth and the inner mouth. an inner layer body connected to the inner layer body and having a volume-reducing and deformable housing portion detachably laminated on the inner surface of the shoulder portion and the body portion, and the outer layer body and the inner layer body are communicated with each other; An outside air introduction port is provided in a mouth portion composed of the outer mouth portion and the inner mouth portion disposed inside the outer mouth portion, and the inner layer body extends radially outward from the outer surface of the inner layer body. At least one double-sided overhanging ridge protrudes and extends vertically so as to correspond to a range extending from the outer opening to the shoulder, wherein the at least one double-sided overhanging ridge extends in the circumferential direction. It has overhangs on both sides, and the overhangs form a space radially inward to secure an airway for outside air in a cross section at the connection between the outer opening and the shoulder . It is characterized by protruding in a direction intersecting with the direction.

In the double container of the present invention having the above configuration, it is preferable that ribs extending in the vertical direction are provided on the shoulder portion of the outer layer body.

A preform assembly of the present invention comprises an outer preform having a tubular outer opening and an extending portion connected to the outer opening, and a tubular inner opening and an extending portion connected to the inner opening. The inner preform protrudes radially outward from the outer surface of the inner preform and extends vertically so as to correspond to a range extending from the outer opening portion to the extension portion of the outer preform. at least one double-sided overhang ridge extending in the direction of the outer preform, the at least one double-sided overhang ridge having overhang portions on both sides in the circumferential direction, and the overhang portions extending from the outer preform to the It is characterized by protruding in a direction crossing the radial direction so as to form a space for securing an airway for outside air radially inward in a cross section at a connecting portion between the outer opening portion and the extending portion .

A method of manufacturing a preform assembly according to the present invention comprises: an inner preform having a tubular inner opening and an extending portion connected to the inner opening; and a tubular outer opening and an extending portion connecting to the outer opening. and a preform assembly step of forming a preform assembly by arranging the inner preform inside the outer preform, The inner preform protrudes radially outward from the outer surface of the inner preform and extends vertically so as to correspond to a range extending from the outer opening portion to the extending portion of the outer preform. The at least one double- sided overhanging ridge has overhanging portions on both sides in the circumferential direction, and the overhanging portions correspond to the outer opening portion and the extending portion of the outer preform. protrudes in a direction intersecting with the radial direction so as to form a space for securing an airway for outside air radially inward in a cross section at a connection portion with the at least The outer surface of the portion where one double-sided overhanging ridge is formed is formed by a split mold split in the radial direction.

A method for manufacturing a double container according to the present invention comprises: an inner preform having a cylindrical inner opening and an extending portion connected to the inner opening; and a cylindrical outer opening and an extending portion connecting to the outer opening. a preform forming step of individually forming an outer preform comprising: a preform assembly step of forming a preform assembly by arranging the inner preform inside the outer preform; and the preform assembly a blow molding step of forming a double container having an outer layer body corresponding to the outer preform and an inner layer body corresponding to the inner preform by placing the three-dimensional body in a mold and performing blow molding; The inner preform protrudes radially outward from the outer surface of the inner preform and extends vertically so as to correspond to a range extending from the outer opening portion to the extending portion of the outer preform. The at least one double- sided overhanging ridge has overhanging portions on both sides in the circumferential direction, and the overhanging portions correspond to the outer opening portion and the extending portion of the outer preform. In the cross section at the connection portion with the outer layer body , it protrudes in a direction crossing the radial direction so as to form a space for securing an airway of the outside air radially inward, and the outer layer body is attached to the outer opening portion via the shoulder portion. having a continuous body, and in the blow molding step radially inward of the overhang portion of the at least one double-sided overhang ridge in cross section at the junction of the outer mouth portion and the shoulder portion. The blow molding is performed so that the space is formed in the

In the method for manufacturing a double container according to the present invention, in the configuration described above, it is preferable that a portion of the inner surface of the mold corresponding to the shoulder portion is provided with a vertically extending ridge or groove.

INDUSTRIAL APPLICABILITY According to the present invention, a double container, a preform assembly, and a preform assembly are manufactured that can reliably secure an airway from an outside air inlet provided in the mouth portion to between the body portion and the containing portion. Methods and methods of making double containers can be provided.

It is a half sectional view showing the important part of the double container which is one embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1; Figure 2 is a half cross-sectional view of a preform assembly to be blow molded into the double container shown in Figure 1;

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

A double container 1, which is an embodiment of the present invention shown in FIG. It has a double structure. The double container 1 can be formed by biaxially stretch blow molding a preform assembly 40 (a preform assembly according to one embodiment of the present invention) shown in FIG. Below, the case where the double container 1 is used as a squeeze-type pouring container for containing liquids such as cosmetics and food seasonings will be described.

As shown in FIG. 1, the outer layer body 10 is a portion constituting the outer shell of the double container 1, and has a bottle shape having an outer mouth portion 11, a shoulder portion 12 and a body portion 13. As shown in FIG.

The outer opening 11 has a cylindrical shape centered on the central axis O. As shown in FIG. A male screw 11a is integrally provided on the outer peripheral surface of the outer opening 11, and a pouring cap (not shown) having a pouring port can be screwed onto the male screw 11a and attached to the outer opening 11. It has become.

The vertical direction means the direction along the central axis O, the upward direction means the direction from the body portion 13 toward the outer mouth portion 11, and the downward direction means the opposite direction. The radial direction means a direction orthogonal to the central axis O, and the circumferential direction means a direction around the central axis O. As shown in FIG. A longitudinal section means a section including the central axis O, and a transverse section means a section perpendicular to the central axis O.

The outer mouth portion 11 may be provided with an annular protrusion instead of the male thread 11a, and may be configured to be attached by engaging the pouring cap in an undercut shape by pressing.

Two external air introduction ports 14 are provided in the outer port portion 11 . The two outside air introduction ports 14 are arranged symmetrically on both sides of the outer port 11 with respect to the central axis O, and are formed in the shape of elongated holes extending in the circumferential direction. there is In other words, each of the outside air introduction ports 14 is configured by a through hole penetrating through the outer port portion 11 . Each outside air introduction port 14 communicates between the outer layer body 10 and the inner layer body 20 , and can introduce the outside air between the outer layer body 10 and the inner layer body 20 . The number, arrangement and shape of the outside air introduction ports 14 are not limited to this and can be designed as appropriate. For example, the outside air inlet 14 may have a perfect circular shape.

A neck ring 11b is integrally provided on the outer peripheral surface of the outer port portion 11 on the shoulder portion 12 side of the outside air introduction port 14 . The neck ring 11b has a flange shape extending over the entire circumference of the outer opening 11 and protrudes radially outward from the outer peripheral surface of the outer opening 11 . The neck ring 11 b is provided slightly above the lower end of the outer opening 11 . That is, in the present embodiment, a cylindrical non-stretched portion that is not substantially stretched during biaxial stretch blow molding is provided immediately below the neck ring 11b. constitutes By providing the non-stretching portion directly under the neck ring 11b in this manner, the neck ring 11b can be prevented from being affected by the stretching. The neck ring 11b may constitute the lower end of the outer opening 11 without providing such a non-extending portion.

The shoulder portion 12 is integrally connected to the lower end of the outer opening portion 11 and protrudes radially outward with respect to the outer opening portion 11 . The longitudinal cross-sectional shape of the shoulder portion 12 in this embodiment is a curved shape that is entirely convex to the outside of the container, but is not limited to this. It may have a curved shape, or may have a linear shape as a whole.

As shown in FIG. 1, the body portion 13 is formed in a bottomed cylindrical shape, and its upper end is integrally connected to the lower end of the shoulder portion 12 . That is, the body portion 13 is connected to the outer mouth portion 11 via the shoulder portion 12 . The cross-sectional shape of the trunk portion 13 may be circular, elliptical or substantially rectangular. Also, the body portion 13 may have a circumferential rib extending in the circumferential direction, or may have a vacuum absorbing panel or the like.

The trunk portion 13 is flexible and can be elastically deformed and dented by squeezing, and can be restored to its original shape by itself from the dented state due to the elastic force. By configuring the body portion 13 to be elastically deformable by squeezing, when the double container 1 is used as a squeeze-type pouring container, it is possible to easily pour out the content liquid. The outer layer body 10 is easily restored to its original shape after the content liquid is poured out, so that the outside air is reliably introduced between the outer layer body 10 and the inner layer body 20 through the outside air introduction port 14 to form the double container. 1 can be reliably exhibited.

The bottom portion of the lower end of the body portion 13 has, for example, a shape in which the inside of the annular outer peripheral edge is recessed, and the double container 1 can be arranged in an upright posture by grounding the bottom portion.

In this embodiment, the outer layer body 10 is made of polyethylene terephthalate (PET). By making the outer layer body 10 from polyethylene terephthalate, the double container 1 can be made lightweight and highly transparent.

The material of the outer layer body 10 is not limited to polyethylene terephthalate, and examples include polyester resin, polyolefin resin, nylon resin, polycarbonate resin (PC resin), cycloolefin copolymer resin (COC resin), and cycloolefin polymer resin (COP resin). Other synthetic resin materials such as can also be adopted. Note that the outer layer body 10 can also have a multi-layer structure in which a plurality of resin layers are provided.

The inner layer body 20 has an inner opening 21 and a housing portion 22 integrally connected to the lower end of the inner opening 21 .

The inner opening 21 has a stepped cylindrical shape and is arranged inside the outer opening 11 coaxially with the outer opening 11 . The inner mouth portion 21 includes an annular flange 21a mounted on the upper end of the outer mouth portion 11, a cylindrical upper cylinder 21b hanging down from the inner peripheral edge of the flange 21a and in contact with the inner surface of the outer mouth portion 11, and an upper cylinder 21b. It has a conical inclined tube 21c whose diameter decreases downward from the lower end of the tube 21b, and a cylindrical lower tube 21d which hangs down from the lower end of the inclined tube 21c. The upper end of the inclined cylinder 21c is located above the upper ends of the two outside air introduction ports 14 . A gap (ventilation path) 23 is provided between the inner peripheral surface of the outer opening 11 and the outer peripheral surface of the lower cylinder 21 d of the inner opening 21 .

Since the outer peripheral surface of the upper cylinder 21b contacts the inner peripheral surface of the outer opening 11 over the entire circumference, the gap 23 between the outer opening 11 and the lower cylinder 21d is formed between the outer opening 11 and the inner opening. The upper end portion of 21 is closed to the outside. The inner opening 21 is vertically positioned with respect to the outer opening 11 by the flange 21 a contacting the upper end of the outer opening 11 .

The accommodating portion 22 is formed in a bag-like shape that is thinner than the body portion 13 , continues to the lower end of the lower cylinder 21 d of the inner mouth portion 21 , and extends along the inner surfaces of the shoulder portion 12 and the body portion 13 . The interior of the containing portion 22 is a space for containing the content liquid. It can be poured out. The containing portion 22 can be peeled off from the inner surface of the body portion 13 and deformed to reduce the volume (deformed to reduce the internal volume) as the content liquid is poured out. At this time, the outside air is introduced between the outer layer body 10 and the inner layer body 20 from the outside air inlet 14, so that only the trunk portion 13 is restored to its original shape, and the accommodating portion 22 is separated from the inner surface of the trunk portion 13. and can be transformed into volume reduction. In the present application, "peeling" means not only the separation of the outer layer body 10 and the inner layer body 20 from the bonded state or the pseudo-bonded state in which almost no adhesive force is interposed, but also the separation of the outer layer body 10 from the adhered state in which no adhesive force is intervened. A case where the inner layer body 20 is separated is also included.

In this embodiment, the inner layer body 20 is made of polyethylene terephthalate. By making the inner layer body 20 from polyethylene terephthalate, the double container 1 can be made lightweight and highly transparent.

The material of the inner layer body 20 is not limited to polyethylene terephthalate, and may be polyester resin, polyolefin resin, nylon resin, polycarbonate resin (PC resin), cycloolefin copolymer resin (COC resin), cycloolefin polymer resin (COP resin), for example. Other synthetic resin materials such as ethylene-vinyl alcohol copolymer resin (EVOH resin) can also be employed. When an ethylene-vinyl alcohol copolymer resin is used as the material for the inner layer 20, one having an appropriate ethylene content can be adopted in consideration of barrier properties and flexibility. The inner layer body 20 can also have a multi-layer structure in which a plurality of resin layers are provided. For example, the inner layer body 20 may have a multilayer structure in which a barrier layer such as an MX nylon resin layer is provided between two polyethylene terephthalate layers in order to ensure barrier properties.

In order to easily secure an airway for the outside air from the outside air introduction port 14 to between the trunk portion 13 and the housing portion 22, the shoulder portion 12 of the outer layer body 10 has a plurality (18 pieces) extending in the vertical direction. A rib 24 is provided. In the present application, the term "rib" means a longitudinally extending portion of the outer layer body 10 formed by locally protruding inside or outside the container. In FIG. 1, only one rib 24 is labeled for convenience.

The plurality of ribs 24 are arranged side by side at equal intervals in the circumferential direction. Each rib 24 extends from the upper end of the shoulder portion 12 to the lower end of the shoulder portion 12 and extends along the radial direction when viewed from above. Each rib 24 is a recessed rib that is recessed when viewed from the outside of the container. Each rib 24 has a U-shaped cross-sectional shape whose width gradually narrows radially inward over substantially the entire length of the cross-sectional surface. The inner layer body 20 is also stretched by biaxial stretch blow molding along the shape of the ribs 24 . Note that the number, arrangement and shape of the ribs 24 are not limited to this, and can be designed as appropriate. For example, each rib 24 may be a convex rib that is convex when viewed from the outside of the container. The upper end of each rib 24 may be positioned below the upper end of the shoulder portion 12 , and the lower end of each rib 24 may be positioned above or below the lower end of the shoulder portion 12 . The positions of the upper ends of the respective ribs 24 do not have to be at the same height. Also, the positions of the lower ends of the respective ribs 24 do not have to be at the same height.

As shown in FIGS. 1 and 2, in order to easily secure an airway for the outside air from the outside air introduction port 14 to between the body portion 13 and the housing portion 22, the inner layer body 20 has an outer surface of the inner layer body 20. A plurality of (ten) ridges 30 are integrally provided so as to protrude radially outward from the outer opening portion 11 and extend vertically so as to correspond to a range spanning from the outer opening portion 11 to the shoulder portion 12 . Here, "extending so as to correspond to" the range extending from the outer mouth portion 11 to the shoulder portion 12 means extending "to face" the range extending from the outer mouth portion 11 to the shoulder portion 12. are doing.

Each ridge 30 extends from a height position corresponding to the outside air inlet 14 to a position reaching the shoulder 12 beyond the neck ring 11b. That is, each ridge 30 extends vertically from the lower surface (outer surface) of the inclined tube 21c to a portion of the accommodating portion 22 corresponding to the shoulder portion 12 . The lower end of each ridge 30 is located at a height corresponding to the connecting portion 15 between the outer opening portion 11 and the shoulder portion 12 (the connecting portion 25 between the inner opening portion 21 and the housing portion 22). The lower end of each ridge 30 gradually decreases in height from the outer surface of the inner layer body 20 downward. Each ridge 30 is radially wider at a height corresponding to the lower end of the outer opening 11 than at the upper portion thereof, in order to increase the adhesion of the outer opening 11 and the shoulder 12 to the connecting portion 15 . The protrusion height to the outside is high. Therefore, a slight gap is formed between the radial outer surface of each ridge 30 and the vertical intermediate portion of the inner peripheral surface of the outer opening 11 . Note that a configuration in which such a gap is not formed may be adopted. The position of the upper end of each ridge 30 may be below the lower surface of the inclined cylinder 21c, and the position of the lower end of each ridge 30 may be positioned at the connecting portion 15 between the outer opening portion 11 and the shoulder portion 12. It may be below the corresponding height. The positions of the upper ends of the respective ridges 30 do not have to be at the same height. Also, the positions of the lower ends of the respective ridges 30 do not have to be at the same height.

In the present embodiment, as shown in FIG. 2 , in order to reliably secure an airway for the outside air from the outside air introduction port 14 to between the body portion 13 and the housing portion 22, the plurality of ridges 30 are provided on the outside. A plurality of (six) overhangs having overhangs 31 protruding in a direction crossing the radial direction so as to form a space S radially inward in the cross section at the connecting portion 15 between the mouth portion 11 and the shoulder portion 12. A hang ridge 32 is included. Each overhang ridge 32, as indicated by the two-dot chain line in FIG. , the space S can ensure a large airway. Therefore, it is possible to reliably secure an airway for outside air at the connecting portion 15 between the outer opening portion 11 and the shoulder portion 12, which is structurally likely to be blocked. In addition, by securing the airway at the connecting portion 15 between the outer mouth portion 11 and the shoulder portion 12 in this way, the airway extending downward can also be secured satisfactorily.

The plurality of overhang ridges 32 include a plurality (two) of double-sided overhang ridges 33 having overhang portions 31 on both sides in the circumferential direction. Each of the double-sided overhanging ridges 33 can secure a large airway by the space S on both sides in the circumferential direction. Each overhang portion 31 of each double-sided overhang ridge 33 is provided over the entire length of the double-sided overhang ridge 33 in the vertical direction. It may be provided only at the connection portion 15 with the portion 12 .

The two double-sided overhang ridges 33 are provided at positions facing each other with the central axis O interposed therebetween. One overhang portion 31 of each double-sided overhang ridge 33 protrudes in a first direction D1, which is a predetermined direction in the cross section. The other overhang portion 31 of each double-sided overhang ridge 33 protrudes in a second direction D2 opposite to the first direction D1 in the cross section.

Two of the four overhanging ridges 32 other than the two double-sided overhanging ridges 33 are positioned away from the end of the inner layer body 20 in the first direction D1 (specifically, double-sided overhanging ridges By protruding in the first direction D1 at a position shifted by 45° in the circumferential direction from the ridge 33, it is configured as an inclined ridge protruding in a direction intersecting the radial direction, and the remaining two are the inner layer body 20 at a position away from the end in the second direction D2 (specifically, a position shifted by 45° in the circumferential direction from the double-sided overhanging ridge 33). It is configured as an inclined ridge protruding in a direction intersecting with the .

Two of the four ridges 30, excluding the six overhang ridges 32, protrude in the first direction D1 near the end of the inner layer body 20 in the first direction D1. The remaining two protrude in the second direction D2 in the vicinity of the ends of the inner layer body 20 in the second direction D2, thereby forming substantially radial ridges. It is configured as a vertical ridge projecting in a direction.

The number, arrangement and shape of the double-sided overhang ridges 33, the overhang ridges 32 and the ridges 30 are not limited to this, and can be designed as appropriate.

An outside air inlet 14 communicating between the outer layer body 10 and the inner layer body 20 is provided in the mouth portion 34 composed of the outer mouth portion 11 and the inner mouth portion 21 arranged inside the outer mouth portion 11 . ing.

The double container 1 having such a structure can be configured as a squeeze container by attaching a pouring cap to the outer opening 11 . In this case, the pouring cap includes, for example, an outside air check valve that allows outside air to be introduced into the outside air introduction port 14 and prevents the outside air from flowing out from the outside air introduction port 14, and a pouring cap for the liquid content. It is possible to use a structure having a check valve for the content liquid that allows the air to flow out and prevents the backflow of the outside air into the housing portion 22 .

In the double container 1 configured as a squeeze container, when the body portion 13 of the outer layer body 10 is squeezed (squeezed), the containing portion 22 is reduced in volume and deformed, and the content liquid is pushed out from the pouring cap and poured out. served. When the squeeze is released after the content liquid has been poured out, the trunk portion 13 is restored to its original shape, and along with this, the storage portion 22 of the inner layer body 20 is peeled off from the inner surface of the outer layer body 10 and the outer layer is released from the outside air inlet 14 . Outside air is introduced between the body 10 and the inner layer body 20, and only the body part 13 is restored to its original shape while the containing part 22 is reduced and deformed. As a result, the content liquid contained in the containing portion 22 can be poured out without being replaced with the outside air, so that the contact of the outside air with the content liquid contained in the containing portion 22 is reduced, thereby preventing its deterioration and deterioration. can be suppressed.

Here, in the double container 1 of the present embodiment, a plurality of ridges 30 including a plurality of overhang ridges 32 are provided. An airway for outside air can be reliably secured so as to reach between the trunk portion 13 and the housing portion 22 beyond the connection portion 15 .

In addition, in the present embodiment, the shoulder portion 12 is provided with a plurality of ribs 24 each extending in the vertical direction and spaced apart in the circumferential direction. Since it is possible to make it difficult for the accommodation portion 22 to re-adhere to the inner surface of the outer layer body 10 after being peeled off from the inner surface of the outer layer body 10, the airway in the shoulder portion 12 can be secured more reliably.

As shown in FIG. 3 , the preform assembly 40 includes an inner synthetic resin preform 60 for forming the inner layer body 20 inside an outer synthetic resin preform 50 for forming the outer layer body 10 . It has a dual structure that incorporates

The outer preform 50 is formed into a predetermined shape corresponding to the outer layer body 10 by injection molding the same synthetic resin material as the outer layer body 10 using a mold. In this embodiment, the outer preform 50 is made of polyethylene terephthalate like the outer layer body 10 .

The outer preform 50 has an outer opening 51 having the same shape as the outer opening 11 of the outer layer body 10 . That is, the outer opening portion 51 is formed in a cylindrical shape, and a male screw 51a is integrally provided on the outer peripheral surface thereof. The outside air introduction ports 52 are provided symmetrically on both sides of the outer port portion 51 with the central axis O interposed therebetween. At the lower end of the outer mouth portion 51, a substantially test tube-shaped extended portion 53 having a hemispherical bottom portion is integrally provided. The thickness of the extending portion 53 is thicker than the thickness of the outer opening portion 51 . The extending portion 53 has a thickness changing portion 53a whose thickness gradually increases downward. Configure. Note that the thickness changing portion 53a may be provided at a portion of the extending portion 53 other than the upper end. A flange-shaped neck ring 51 b is integrally provided with the outer opening 51 .

The inner preform 60 is formed into a predetermined shape corresponding to the inner layer body 20 by injection molding the same synthetic resin material as the inner layer body 20 using a mold. In this embodiment, the inner preform 60 is made of polyethylene terephthalate like the inner layer body 20 .

The inner preform 60 has an inner opening 61 having the same shape as the inner opening 21 of the inner layer body 20 . That is, the inner opening 61 has a stepped cylindrical shape and is arranged inside the outer opening 51 coaxially with the outer opening 51 . The inner mouth portion 61 includes an annular flange 61a mounted on the upper end of the outer mouth portion 51, a cylindrical upper cylinder 61b hanging down from the inner peripheral edge of the flange 61a and in contact with the inner surface of the outer mouth portion 51, and an upper cylinder 61b. It has a conical inclined tube 61c whose diameter decreases downward from the lower end of the tube 61b, and a cylindrical lower tube 61d which hangs down from the lower end of the inclined tube 61c. Since the outer peripheral surface of the upper cylinder 61b contacts the inner peripheral surface of the outer opening 51 over the entire circumference, the upper end portion of the gap (air passage) 62 between the outer opening 51 and the lower cylinder 61d is exposed to the outside. blocked against. The inner opening 61 is vertically positioned with respect to the outer opening 51 by abutting the flange 61 a on the upper end of the outer opening 51 . At the lower end of the inner opening 61, a substantially test-tube-shaped extended portion 63 having a hemispherical bottom is integrally provided. The outer diameter of the extending portion 63 is smaller than the outer diameter of the inner opening portion 61 . A gap is provided between the outer peripheral surface of the extending portion 63 and the inner peripheral surface of the extending portion 53, and when the inner preform 60 is assembled inside the outer preform 50, the outer peripheral surface of the extending portion 63 and the extending portion 53 are separated from each other. It is designed to prevent damage to the inner peripheral surface of the

A plurality of ridges 70 corresponding to the plurality of ridges 30 are provided on the outer surface of the inner preform 60 . The plurality of ridges 70 protrude radially outward from the outer surface of the inner preform 60 and extend vertically so as to correspond to a range extending from the outer opening 51 to the extending portion 53 of the outer preform 50 . . Here, "extending so as to correspond to" the range extending from the outer opening portion 51 to the extending portion 53 means extending "to face" the range extending from the outer opening portion 51 to the extending portion 53. are doing. Each ridge 70 extends from a height position corresponding to the outside air introduction port 52 to a position reaching a height corresponding to the extending portion 53 beyond the neck ring 51b. The lower end of each ridge 70 is located at a height corresponding to the connecting portion 54 between the outer opening portion 51 and the extending portion 53 (the connecting portion 64 between the inner opening portion 61 and the extending portion 63). In addition, the lower end of each ridge 70 may be positioned below the height corresponding to the connecting portion 54 between the outer opening portion 51 and the extending portion 53 . The lower end of each ridge 70 gradually decreases in height from the outer surface of the inner preform 60 downward. Each of the ridges 70 protrudes radially outward at the lower end of the outer opening 51 to a height higher than that at the upper end. In addition, it is good also as a structure which does not provide such a change of protrusion height. A slight gap is formed between the portion of the radially outer side surface of each ridge 70 where the protruding height is increased and the inner peripheral surface of the outer opening 51, and the inner preform 60 is replaced by the outer preform. The inner peripheral surface of the outer opening portion 51 is designed not to be damaged when it is assembled inside the outer opening portion 50 . Note that a configuration in which such a gap is not formed may be adopted. The plurality of ridges 70 have basically the same shape as the plurality of ridges 30 of the inner layer body 20 .

The cross-sectional shape of the plurality of ridges 70 is the same as that of FIG. 2 showing the double container 1, so it is not shown. A plurality (six) of overhang ridges 72 having overhang portions 71 projecting in a direction intersecting the radial direction so as to form a space radially inwardly in a cross section at the connection portion 54 of . The plurality of overhang ridges 72 include a plurality (two) of double-sided overhang ridges 73 having overhang portions 71 on both sides in the circumferential direction. Each overhang portion 71 in each double-sided overhang ridge 73 is provided over the entire length of the double-sided overhang ridge 73 in the vertical direction, but is not limited to this. It may be provided only at the connecting portion 54 with the portion 53 .

The two double-sided overhang ridges 73 are provided at positions facing each other with the central axis O interposed therebetween. One overhang portion 71 of each double-sided overhang ridge 73 protrudes in a first direction, which is a predetermined direction in the cross section. The other overhang portion 71 of each double-sided overhang ridge 73 protrudes in a second direction opposite to the first direction in the cross section. Two of the four overhang ridges 72 excluding the two double-sided overhang ridges 73 protrude in the first direction at positions away from the ends of the inner preform 60 in the first direction. , projecting in a direction intersecting the radial direction, and the remaining two projecting in the second direction at a position away from the end of the inner preform 60 in the second direction. Thus, it is configured as an inclined ridge that protrudes in a direction that intersects with the radial direction. Two of the four ridges 70 excluding the six overhang ridges 72 protrude in the first direction near the ends of the inner preform 60 in the first direction, thereby substantially increasing the diameter. and the remaining two protrude in the second direction near the second direction end of the inner preform 60 so as to extend substantially radially. It is configured as a protruding vertical ridge.

An outside air introduction port 52 communicating between the outer preform 50 and the inner preform 60 is provided in the mouth portion 74 composed of the outer opening portion 51 and the inner opening portion 61 disposed inside the outer opening portion 51 . is provided.

The preform assembly 40 shown in FIG. 3 can be manufactured, for example, in the following manner (preform assembly manufacturing method according to one embodiment of the present invention).

The method of manufacturing a preform assembly according to the present embodiment has a preform forming step and a preform assembling step. The method of manufacturing a preform assembly according to the present embodiment can also be applied to manufacturing preform assemblies other than the preform assembly 40 shown in FIG.

In the preform forming step, the inner preform 60 and the outer preform 50 are individually formed by injection molding. At this time, at least the outer surface of the portion of the inner preform 60 on which the plurality of overhanging ridges 72 are formed is formed by split molds that are divided in the radial direction. Here, the split mold includes a first mold portion forming the overhang portion 71 projecting in the first direction in the two double-sided overhanging ridges 73, and a second mold portion in the two double-sided overhanging ridges 73. and a second mold portion forming an overhang 71 that protrudes outwards. Here, the split mold is opened by moving the first mold part in the first direction and the second mold part in the second direction, and the formed inner preform 60 is taken out. can be done. It should be noted that the first mold part is also configured to form two vertical ridges projecting in a first direction and two angled ridges, and the second mold part has two ridges projecting in a second direction. It is configured to also form two vertical ridges and two angled ridges.

In the preform assembly process, the inner preform 60 is assembled inside the outer preform 50, and the outside air introduction port 52 communicating between the outer preform 50 and the inner preform 60 is formed between the outer opening portion 51 and the outer opening. The preform assembly 40 provided in the mouth portion 74 is formed by the inner mouth portion 61 located inside the portion 51 .

The double container 1 shown in FIG. 1 can be manufactured, for example, in the following manner (method for manufacturing a double container according to one embodiment of the present invention).

The method for manufacturing a double container according to the present embodiment includes a preform forming step, a preform assembling step, and a blow molding step. The method for manufacturing a double container according to the present embodiment can also be applied to manufacturing a double container other than the double container 1 shown in FIG.

The preform forming process and the preform assembling process of this embodiment are the same as the preform forming process and the preform assembling process in the method of manufacturing the preform assembly according to the embodiment of the present invention described above.

In the blow molding process, the preform assembly 40 is subjected to biaxial stretch blow molding using a mold (not shown) having an inner surface having a shape corresponding to the shoulder portion 12 and the body portion 13 of the double container 1 to form the double container. 1. At this time, the blow molding is performed so that a space S is formed radially inside the overhang portion 31 of the plurality of overhang ridges 32 in the cross section at the connection portion 15 between the outer opening portion 51 and the shoulder portion 12 . In other words, the space S is formed by blow molding the preform assembly 40 having the overhang ridges 32 . In addition, a plurality of vertically extending ridges are provided on the inner surface of the mold corresponding to the shoulder portion 12 , thereby forming a plurality of concave ribs 24 on the shoulder portion 12 . When forming a plurality of convex ribs 24 instead of the plurality of concave ribs 24, a plurality of vertically extending grooves are formed on the inner surface of the mold corresponding to the shoulder portion 12. will be provided.

It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

In the above-described embodiment, the outside air introduction ports 52 and 14 are provided in the outer port portions 51 and 11 and are through holes penetrating the outer port portions 51 and 11. However, the present invention is not limited to this. It can also be configured as a gap provided between the upper ends of the portions 51 and 11 and the upper ends of the inner openings 61 and 21 to open the air passage to the outside.

In the above-described embodiment, the outside air introduction port 14 of the double container 1 is formed by providing the outside air introduction port 52 in advance in the preform assembly 40 blow-molded into the double container 1, but this is not the only option. Instead, for example, it may be formed by post-processing after blow molding.

Although the neck rings 51b and 11b are provided in the above-described embodiment, the configuration is not limited to this, and the neck rings 51b and 11b may not be provided.

The shape of the shoulder portion 12 and the body portion 13 can also be changed in various ways.

In the above-described embodiment, the double container 1 is a squeeze-type pouring container in which a pouring cap having a pouring port is attached to the outer mouth portion 11, and the content liquid is poured out by squeezing the body portion 13. However, it is assumed to be used for a pump-equipped container in which the body portion 13 has a predetermined rigidity that does not easily squeeze deformation, and the pump-type pouring tool is attached to the outer mouth portion 11. can also

In the above-described embodiment, the plurality of overhang ridges 72, 32 includes a plurality of double-sided overhang ridges 73, 33. However, the present invention is not limited to this, and the plurality of overhang ridges 72, 32 is one. A configuration including only the double-sided overhanging ridges 73, 33 may be employed, or a configuration in which the plurality of overhanging ridges 72, 32 do not include the double-sided overhanging ridges 73, 33 may be employed. Further, in the above-described embodiment, the plurality of ridges 70, 30 includes a plurality of overhang ridges 72, 32. A configuration including the hang ridges 72 and 32 may be employed. In this case, only one overhanging ridge 72, 32 may be the double-sided overhanging ridge 73, 33, or may not be the double-sided overhanging ridge 73, 33. Furthermore, although a plurality of ridges 70 and 30 are provided in the above embodiment, the present invention is not limited to this, and only one ridge 70 and 30 may be provided. In this case, only one ridge 70, 30 may be double-sided overhang ridges 73, 33, or may be overhang ridges 72, 32 that are not double-sided overhang ridges 73, 33. good.

Although the rib 24 is provided on the shoulder portion 12 in the above-described embodiment, the configuration is not limited to this and the rib 24 may not be provided.

1 double container 10 outer layer body 11 outer mouth portion 11a male screw 11b neck ring 12 shoulder portion 13 body portion 14 outside air introduction port 15 connection portion between outer mouth portion and shoulder portion 20 inner layer body 21 inner mouth portion 21a flange 21b upper cylinder 21c Inclined tube 21 d Lower tube 22 Accommodating portion 23 Gap 24 Rib 25 Connecting portion 30 between inner opening and accommodating portion Projection 31 Overhang 32 Overhang projection 33 Double-sided overhang projection 34 Mouth 40 Preform assembly 50 Outer preform 51 Outer opening 51a Male screw 51b Neck ring 52 Outside air inlet 53 Extended portion 53a Thickness change portion 54 Connecting portion 60 between outer opening and extending portion Inner preform 61 Inner opening 61a Flange 61b Upper tube 61c Inclined tube 61d Lower cylinder 62 Gap 63 Extension part 64 Connection part 70 between inner opening and extension part Projection 71 Overhang 72 Overhang projection 73 Double-sided overhang projection 74 Mouth O Central axis S Space D1 First direction D2 second direction

Claims (6)

an outer layer body comprising a cylindrical outer opening and a bottomed cylindrical body connected to the outer opening via a shoulder;
an inner layer body comprising a tubular inner opening and a volume-reducing and deformable accommodating portion connected to the inner opening and detachably laminated on the inner surfaces of the shoulder portion and the body portion;
an outside air introduction port that communicates between the outer layer body and the inner layer body is provided in a mouth portion composed of the outer mouth portion and the inner mouth portion disposed inside the outer mouth portion;
The inner layer body has at least one double-sided overhang ridge protruding radially outward from the outer surface of the inner layer body and extending vertically so as to correspond to a range spanning from the outer opening portion to the shoulder portion. death,
The at least one double-sided overhanging ridge has overhangs on both sides in the circumferential direction,
The overhang protrudes in a direction intersecting with the radial direction so as to form a space for securing an airway for outside air radially inward in a cross section at a connection portion between the outer opening and the shoulder . A double container characterized by: 2. The double container according to claim 1 , wherein vertically extending ribs are provided on said shoulder portion of said outer layer body. an outer preform comprising a tubular outer opening and an extending portion connected to the outer opening;
an inner preform having a cylindrical inner opening and an extending portion connected to the inner opening;
The inner preform protrudes radially outward from the outer surface of the inner preform and extends vertically so as to correspond to a range extending from the outer opening portion to the extending portion of the outer preform. Has overhang ridges on both sides ,
The at least one double-sided overhanging ridge has overhangs on both sides in the circumferential direction,
The overhang portion intersects with the radial direction so as to form a space radially inward for securing an airway for outside air in a cross section at a connection portion between the outer opening portion and the extension portion of the outer preform. A preform assembly characterized by projecting in a direction. A method of manufacturing a preform assembly, comprising:
An inner preform having a cylindrical inner opening and an extending portion connected to the inner opening, and an outer preform having a cylindrical outer opening and an extending portion connecting to the outer opening are separately formed. a preform forming step to
a preform assembly step of arranging the inner preform inside the outer preform to form a preform assembly,
The inner preform protrudes radially outward from the outer surface of the inner preform and extends vertically so as to correspond to a range extending from the outer opening portion to the extending portion of the outer preform. Has overhang ridges on both sides ,
The at least one double-sided overhanging ridge has overhangs on both sides in the circumferential direction,
The overhang portion intersects with the radial direction so as to form a space radially inward for securing an airway for outside air in a cross section at a connection portion between the outer opening portion and the extension portion of the outer preform. protrude in the direction of
A preform assembly characterized in that , in the preform forming step, the outer surface of the portion of the inner preform on which the at least one double-sided overhang ridge is formed is formed by a split mold that is divided in the radial direction. manufacturing method. A method of manufacturing a double container, comprising:
An inner preform having a cylindrical inner opening and an extending portion connected to the inner opening, and an outer preform having a cylindrical outer opening and an extending portion connecting to the outer opening are separately formed. a preform forming step to
a preform assembly step of arranging the inner preform inside the outer preform to form a preform assembly;
a blow molding step of forming a double container having an outer layer body corresponding to the outer preform and an inner layer body corresponding to the inner preform by placing the preform assembly in a mold and performing blow molding; has
The inner preform protrudes radially outward from the outer surface of the inner preform and extends vertically so as to correspond to a range extending from the outer opening portion to the extending portion of the outer preform. Has overhang ridges on both sides ,
The at least one double-sided overhanging ridge has overhangs on both sides in the circumferential direction,
The overhang portion intersects with the radial direction so as to form a space radially inward for securing an airway for outside air in a cross section at a connection portion between the outer opening portion and the extension portion of the outer preform. protrude in the direction of
The outer layer body has a trunk portion connected to the outer mouth portion via a shoulder portion,
In the blow molding step, the space is formed radially inside the overhang portion of the at least one double-sided overhang ridge in the cross section at the connection portion between the outer opening portion and the shoulder portion. A method for manufacturing a double container, characterized by blow molding. 6. The method of manufacturing a double container according to claim 5 , wherein a portion of the inner surface of the mold corresponding to the shoulder portion is provided with a vertically extending ridge or groove.

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