DOUBLE CONTAINER FOR HIGH-VISCOSITY LIQUID

Abstract

Provided is a double container which comprises a relatively rigid outer container and a flexible inner container disposed inside the outer container and capacity-variable in response to an amount of a content thereof The double container is configured to contain, particularly, a high-viscosity liquid, e.g., a liquid having a viscosity of 1000 to 100,000 mPa/s, and to be easily produced by a forming technique having no significant difference from conventional techniques, wherein the double container for a high-viscosity liquid is capable of containing the content without causing oxidation thereof, while maintaining the outer container in its original shape or dimensions, and discharging the content by squeezing the outer container, irrespective of a level of a remaining amount of the content.

Claims

1-7. (canceled)

8. A double container molded from a parison by using a split mold having at least a pair of partial molds, said parison comprising at least two layers of a rigid outer container layer and a flexible inner container layer, said two layers being partly separable from each other after molding, and external air being introduced into a space formed between said rigid outer container layer and said flexible inner container layer so that a flexible inner container being contracted while a rigid outer container being maintained in shape, the double container comprising a bottle body removed a bottom burr which is formed by putting the parison between at least partially bottom portions of said partial molds, and a covering member for isolating air-tightly an outside of the bottle body including a portion removed said bottom burr from the outside air and having a one-way valve for introducing the outside air into the space between the bottle body and the covering member.

9. The double container as recited in claim 8, wherein the one-way valve is fixed to an inside bottom cap attached to the bottom portion of the rigid outer container layer.

10. The double container as recited in claim 8, wherein the one-way valve is covered by an outside bottom cap attached to the bottom portion of the rigid outer container layer.

11. A liquid which is contained in the double container as recited in claim 8, wherein the liquid has a viscosity of 1000 to 100,000 mPa/s.

12. A liquid which is contained in the double container as recited in claim 8, wherein the liquid is mayonnaise.

13. A liquid which is contained in the double container as recited in claim 8, wherein the liquid is grease.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0029] FIG. 1 is a vertical sectional view depicting a double container for a high-viscosity liquid, according to a first embodiment of the present invention.

[0030] FIGS. 2(a) and 2(b) depict the double container according to the first embodiment, wherein FIG. 2(a) is a vertical sectional view depicting an entirety thereof, and FIG. 2(b) is a vertical sectional view depicting an area indicated by the dotted line B in FIG. 2(a).

[0031] FIG. 3 is a perspective view depicting a first example of a one-way valve used in the double container according to the first embodiment.

[0032] FIG. 4 is a sectional view taken along the line IV-IV in FIG. 3.

[0033] FIG. 5 is a perspective view depicting a one-way valve used in a modification of the double container according to the first embodiment.

[0034] FIG. 6 is a sectional view depicting the one-way valve used in the modification of the double container according to the first embodiment and a vicinity thereof.

[0035] FIG. 7 is a vertical sectional view depicting a double container for a high-viscosity liquid, according to a second embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

First Embodiment

(Configuration)

[0036] As depicted in FIG. 1, a double container 10 for a high-viscosity liquid, according to a first embodiment of the present invention, is capped by a container cap 18 equipped with a packing 16 and threadably mounted on a discharge port 14 of a bottle body 12.

[0037] A bottom region of the bottle body 12 has a recessed portion 20 having an annular shape and extending horizontally, a conical surface portion 22 located just below the recessed portion 20, a hermetically-sealed circular cylindrical portion 24 located just below the conical surface portion 22, and a bottom portion 26 forming a bottom of the hermetically-sealed circular cylindrical portion 24.

[0038] A lower section of the double container 10 is provided with: an outside bottom cap 30 fitted in the recessed portion 20; an inside bottom cap 32 fitted on the hermetically-sealed circular cylindrical portion 24 and fitted in the outside bottom cap 30; and a one-way valve 40 fitted in a valve-receiving hole 34 formed in a central region of the inside bottom cap 32. An adhesive may be used for the fitting of the inside bottom cap 32 with respect to the hermetically-sealed circular cylindrical portion 24, and the fitting of the one-way valve 40 with respect to the valve-receiving hole 34, so as to ensure fitting engagement and hermetical sealing.

[0039] The bottle body 12 is formed by clamping a parison using a split-type forming die, and then applying a blow pressure to an inside of the parison so as to press the parison against a cavity of the forming die. As depicted in FIGS. 2(a) and 2(b), the bottom body 12 comprises: a trilaminar flexible inner layer 50 consisting of a low-density polyethylene (LDPE) sub-layer, an adhesive sub-layer such as a polyolefin-based adhesive resin, and an ethylene-vinylalcohol copolymer (EVOH) sub-layer; and a rigid outer layer 52 made of polypropylene (PP), which are arranged in this order in an outward direction.

[0040] There is no adhesivity between the flexible inner layer 50 and the rigid outer layer 52 of the bottle body 12, so that they are easily separable from each other. However, in an upper section of the bottle body 12, particularly the discharge port 14, a cross-sectional area of a discharge passage is not significantly different from an original cross-sectional area of the parison, i.e., an expansion caused by the blow pressure is small and an original thickness of the parison is substantially maintained. That is, in the upper section, the flexible inner layer 50 and the rigid outer layer 52 formed integrally are generally solidly integrated together and never separated from each other.

[0041] In the lower section of the bottle body 12, a portion of the parison located below the bottom portion 26 is formed as a bottom burr 60 through a pinched portion PP. In the bottom burr 60, the flexible inner layer 50 defining respective inner surfaces of the conical surface portion 22, the hermetically-sealed circular cylindrical portion 24 and the bottom portion 26 exists as one central layer thereof. Two rigid outer layers 52 exist, respectively, as opposite lateral layers of the bottom burr 60, namely on both sides of the flexible inner layer 50.

[0042] On the basis of the presence of the pinched portion PP having a small cross-sectional area, the bottom burr 60 can be easily pulled away from the bottle body 12. As can be understood from FIG. 2(b), in an area of the bottom portion 26 from which the bottom burr 60 has been pulled away, an edge of the one flexible inner layer 50 and edges of the rigid outer layers 52 on both sides of the flexible inner layer 50 are exposes to outside. When the flexible inner layer 50 and the rigid outer layer 52 are separated from each other and a pressure therebetween becomes lower, portions of the flexible inner layer 50 and the rigid outer layer 52 in the area of the bottom portion 26 from which the bottom burr 60 has been pulled away are also separated from each other to form a thin gap therebetween. Thus, a gap, i.e., space, formed as a result of the separation between the flexible inner layer 50 and the rigid outer layer 52 is maintained at 1 atm which is equal to an ambient pressure, by air introduced through the thin gap.

[0043] The outside bottom cap 30 is molded using an olefin-based resin such as polypropylene or high-density polyethylene (HDPE), or a relatively rigid resin.

[0044] The inside bottom cap 32 is also molded using an olefin-based resin such as polypropylene or high-density polyethylene (HDPE), or a relatively rigid resin.

[0045] The one-way valve 40 is molded using an elastic resin such as thermoplastic elastomer. As depicted in FIGS. 3 and 4, the one-way valve 40 comprises a disk-shaped base plate portion 70, and a chevron-shaped portion 74 gradually rising from one surface 72 of the base plate portion 70. The chevron-shaped portion 74 has a rectangular-shaped top edge face 76 whose central region is formed with an air inlet groove 80 extending to the other surface 78 the base plate portion 70.

[0046] Referring to FIG. 4, when a high pressure is applied to the one-way valve 40 from a direction indicated by the arrowed line 82, i.e., a pressure in a region where the arrowed line 84 is described becomes lower than that in a region where the arrowed line 82 is described, the chevron-shaped portion 74 is deformed to open the air inlet groove 80 to introduce air in the direction indicated by the arrowed line 82.

[0047] On the other hand, when a high pressure is applied from a direction indicated by the arrowed line 84, i.e., a pressure in the region where the arrowed line 82 is described becomes lower than that in the region where the arrowed line 84 is described, the chevron-shaped portion 74 is compressed to tightly close the air inlet groove 80 to make it possible to release air in the direction indicated by the arrowed line 84.

[0048] In a modification of the first embodiment, a one-way valve 140 is also molded using an elastic resin such as thermoplastic elastomer. As depicted in FIGS. 5 and 6, the one-way valve 140 comprises a disk-shaped body whose central region is formed with a C-shaped air inlet groove 142. The air inlet groove 142 is defined by opposed side surfaces of the disk-shaped body. However, when no external load is applied thereto, the air inlet groove 142 is closed to make it impossible to pass air through the one-way valve 140.

[0049] As depicted in FIG. 6, the one-way valve 140 is fitted into an annular-shaped recessed inner groove 190 formed in a central region of an inside bottom cap 132. The inside bottom cap 132 has a lower support portion 192 formed on the side of external air to protrude along a lower surface of the recessed inner groove 190 so as to cover the air inlet groove 142, and an upper support portion 194 formed on an inward side of the inside bottom cap 132 to protrude along an upper surface of the recessed inner groove 190 without covering the air inlet groove 142.

[0050] Referring to FIG. 6, when a high pressure is applied to the one-way valve 140 from a direction indicated by the arrowed line 82, a portion VV surrounded by the C-shaped air inlet groove 142 is deformed to expand the air inlet groove 142 to introduce air in the direction indicated by the arrowed line 82.

[0051] On the other hand, when a high pressure is applied to the one-way valve 140 from a direction indicated by the arrowed line 84, the air inlet groove 142 is not expanded because the portion VV is supported by the lower support portion 192, so that it is impossible to release air in the direction indicated by the arrowed line 84.

(Functions)

[0052] A high-viscosity liquid such as mayonnaise is contained in the aforementioned double container 10. The container cap 18 is detached, and the rigid outer layer 52 is squeezed to push the content out from the discharge port 14. After pushing out the content by a given amount, the double container 10 is placed on a horizontal surface of a table or the like to stand upright.

[0053] In response to a decrease in squeezing force against the double container 10, the rigid outer layer 52 is urged to return to its original shape. On the other hand, the content located in the discharge port 14 has a given viscosity, so that external air is not introduced and thereby the flexible inner layer 50 cannot be deformed to increase its capacity. Thus, the flexible inner layer 50 and the rigid outer layer 52 are separated from each other to form a low-pressure space therebetween. According to this low pressure, the air inlet groove 80 is opened to allow external air to be introduced. As a result of introduction of external air through the air inlet groove 80, a pressure in the space formed by the separation between the flexible inner layer 50 and the rigid outer layer 52 is set to 1 atm, and kept in a stable state.

[0054] Subsequently, the rigid outer layer 52 is squeezed to further discharge the content. In this case, the pressure in the space between the flexible inner layer 50 and the rigid outer layer 52 becomes greater than 1 atm, so that the air inlet groove 80 is closed to make it impossible to release air through the one-way valve 40. As a result of further squeezing of the rigid outer layer 52, the pressure in the space between the flexible inner layer 50 and the rigid outer layer 52 becomes greater than 1 atm, and the flexible inner layer 50 is squeezed by the pressure greater than 1 atm, so that the content is discharged.

Second Embodiment

(Configuration)

[0055] A configuration of a double container 210 for a high-viscosity liquid, according to a second embodiment of the present invention, will be described below. In the following description, the same element or component as that in the double container 10 according to the first embodiment is assigned with the same reference sign as that in the first embodiment, and its description will be omitted.

[0056] A lower portion of the double container 210 is, as shown in FIG. 7, provided with: an outside bottom cap 230 fitted in a recessed portion 20; an inside bottom cap 232 fitted on a hermetically-sealed circular cylindrical portion 224 of a bottle body 12; and a one-way valve 40 fitted in a valve-receiving hole 234 formed in a central region of the inside bottom cap 232. An adhesive may be used for the fitting of the inside bottom cap 232 with respect to the hermetically-sealed circular cylindrical portion 224, and the fitting of the one-way valve 40 with respect to the valve-receiving hole 234, so as to ensure fitting engagement and hermetical sealing.

[0057] An upper end of the outside bottom cap 230, i.e., a portion of the outside bottom cap 230 fitted in the recessed portion 20 of the bottle body 12, is formed with a plurality of upward air inlet grooves 292 each extending obliquely upwardly. The upward air inlet grooves 292 communicate between an inside and an outside of the outside bottom cap 230 along the recessed portion 20.

[0058] A lower portion of the double container 210 is provided with: an inside bottom cap 232 fitted on a hermetically-sealed circular cylindrical portion 224 of a bottle body 12; and a one-way valve 40 fitted in a valve-receiving hole 234 formed in a central region of the inside bottom cap 232. An adhesive may be used for the fitting of the inside bottom cap 232 with respect to the hermetically-sealed circular cylindrical portion 224, and the fitting of the one-way valve 40 with respect to the valve-receiving hole 234, so as to ensure fitting engagement and hermetical sealing.

[0059] An advantage of the double container 210 is in that, even in a situation where the double container 210 is placed on a location where water is accumulated, the double container 210 can be normally used without sucking water, as long as a water depth in the location is less than a height dimension of the outside bottom cap 230.

LIST OF REFERENCE SIGNS

[0060] PP: pinched portion [0061] 10, 210: double container for high-viscosity liquid [0062] 12: bottle body [0063] 14: discharge port [0064] 18: container cap [0065] 20: recessed portion [0066] 22: conical surface portion [0067] 24, 224: hermetically-sealed circular cylindrical portion [0068] 26: bottom portion [0069] 30, 230: outside bottom cap [0070] 32, 132, 232: inside bottom cap [0071] 34, 234: valve-receiving hole [0072] 40, 140: one-way valve [0073] 50: flexible inner layer [0074] 52: rigid outer layer [0075] 60: bottom burr [0076] 70: base plate portion [0077] 74: chevron-shaped portion [0078] 76: top edge face [0079] 82, 84: arrowed line [0080] 180: air inlet groove [0081] 190: recessed inner groove [0082] 192: lower support portion [0083] 194: upper support portion [0084] 292: upward air inlet grooves