JP2002264944A - Composite container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite container wherein even if an expansion portion of a parison is expanded, a sufficient strength can be obtained, and the end of an opening of an outer container can be prevented from being damaged, while an improved design and usability is provided. SOLUTION: The composite container includes a pulp-molded outside container 2 made of paper and an inside container 3 made of a thermoplastic resin and blow-molded in the container 2. The container 2 has a shoulder 21 tapering off toward the end 20 of its opening, while an expansion portion 31 of the parison 30 made of a thermoplastic resin and placed at the end 20 is expanded so that the container 3 is made integral to the container 2, thereby providing the composite container. The parison 30 has a flange 30a covering the end 20 of the opening so that the container 2 is held by the flange 30a and the shoulder 21, while the thickness of the expansion portion 31 is 30-300 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite container provided with an outer container made of paper formed by a pulp molding method and an inner container made of a thermoplastic resin blow-molded in the outer container.

[0002]

2. Description of the Related Art As a prior art relating to a composite container in which a thermoplastic resin inner bag is disposed inside a paper container or a paper body frame by blow molding, for example, there is a special technology. The containers described in Japanese Unexamined Patent Publication Nos. 54-133392 and 58-149328 are known. In these containers, a bulging portion of a parison made of a thermoplastic resin is bulged in an outer container made of paper to form an inner container, which is integrated with the outer container.

In the above-mentioned container, since the outer container made of paper has only a trunk or a shoulder, the bulging portion of the parison is partially exposed. For this reason, even when the inner container is made thin, the exposed portion must be made thick in order to secure the strength, and it is difficult to control the thickness. Further, since the open end of the outer paper container is exposed to the outside as it is, the outer container is easily damaged at the open end, which is not preferable in design.

Accordingly, it is an object of the present invention to provide a parison having a sufficient strength even when the bulging portion is bulged to a small thickness, the outer container is less likely to be damaged at the open end, and has an excellent design. It is to provide a composite container which is easy.

[0005]

The present invention comprises an outer container made of paper formed by a pulp molding method and an inner container made of a thermoplastic resin formed by a blow molding method in the outer container. The outer container has a shoulder portion tapered toward an open end, and the inner container bulges a bulge portion of a thermoplastic resin parison disposed at the open end. In a composite container integrated with an outer container, the parison has a flange portion covering the open end, and the outer container is sandwiched between the flange portion and the bulging portion. The thickness of the bulging part is 30 to 300 μm
The above object has been achieved by providing a composite container characterized by the following.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. FIG. 1 shows a first embodiment of the composite container of the present invention. In the figure, reference numeral 1 indicates a composite container.

As shown in FIG. 1, a composite container 1 comprises a paper outer container 2 formed by a pulp molding method,
An inner container 3 made of a thermoplastic resin formed by a blow molding method in the outer container 2, wherein the outer container 2 has a shoulder 21 tapering toward an open end 20, and the inner container 3 is This is a composite container in which a bulging portion 31 of a parison 30 made of a thermoplastic resin fitted to the opening end 20 is bulged and integrated with the outer container 2.

In this embodiment, the outer container 2 is a bottomed cylindrical bottle container having a mouth and neck portion 22 connected to the shoulder portion 21. The thickness of the portion (shoulder, trunk, bottom) of the outer container 2 where the bulging portion 31 is integrated is set at 0. 0 from the viewpoint that the strength of the container can be sufficiently obtained even if the bulging portion is made thin. 1
To 5.0 mm, preferably 0.3 to 3.0 m
m is more preferable.

The parison 30 has a flange portion 30a that covers the opening end portion 20, and the flange portion 30a has a peripheral wall portion 30b that hangs down from the peripheral edge portion and covers the outer peripheral surface 22b of the mouth and neck portion 22. . The outer container 2 is sandwiched between the peripheral wall portion 30 of the flange portion 30a and the bulging portion 31.

The thickness of the bulging portion 31 of the parison is 30 to
It is 300 μm, preferably 50 to 250 μm, more preferably 80 to 200 μm. When the thickness of the bulging portion is less than 30 μm, it is difficult to mold the inner container.

The fibers used for the outer container 2 include wood pulp fibers such as waste paper pulp and virgin pulp, reeds,
Non-wood fibers such as straw, hemp and wool, and synthetic pulp are used.

The outer container 2 may contain other additives such as a molding aid, a surfactant, an antifungal agent, a paper-strengthening agent, and a sizing agent, if necessary, in addition to the fibers. Can be.

Further, it is preferable that a coloring pigment is blended in the outer container from the viewpoint of enhancing decorativeness. Examples of the coloring pigment include inorganic pigments such as titanium oxide, zinc oxide, carbon black, graphite, and iron oxide, and organic pigments such as a phthalocyanine pigment. Further, it is preferable to include a fixing agent from the viewpoint of improving the fixability of the color pigment.

Preferably, a coating layer is formed on the surface of the outer container with a resin such as an acrylic resin, a styrene resin, a urethane resin, a melamine resin, or an olefin resin, if necessary. Among the above, the resin forming the coating layer is preferably an acrylic resin or a melamine resin in terms of enhancing the hardness of the surface on which the coating layer is formed, and in terms of friction of the surface, an acrylic resin or a urethane-based resin. Resins are preferred,
Acrylic resins are preferred in terms of enhancing the surface hardness, friction and waterproofing. These resins can be used alone or in combination of two or more. The coating layer is formed by spraying a liquid material of these resins (including a melt, a solution, and an emulsion (including aqueous and non-aqueous)) onto the surface of the paper fiber layer, or by immersing these surfaces in the liquid. , And then dried. Further, it can be formed by bonding a film of these resins to the surface of the paper fiber layer. The coating layer may be appropriately blended with the coloring pigment.

The parison 30 is made of a polyolefin such as polyethylene or polypropylene, a polyester such as polyethylene terephthalate, or a thermoplastic resin such as polyamide or polycarbonate. Is preferably used. Further, it is preferable to mix low-molecular-weight polyethylene into the parison 30 from the viewpoint of increasing the adhesiveness between the bulging portion 31 and the inner surface of the outer container. The compounding amount of the low molecular weight polyethylene is 0.1 to 0.1 with respect to the thermoplastic resin.
The content is preferably 10 wt%, more preferably 0.5 to 5 wt%.

In the composite container 1 of the present embodiment, first, the outer container 2 is manufactured by a pulp molding method. That is, for example, the outer container 2 is formed by forming a cavity by assembling a papermaking mold composed of a set of split molds using the slurry of the fiber as a raw material, and forming the cavity inside the cavity with the inner surface of the cavity covered with a papermaking net. While supplying the slurry, negative pressure suction is performed from outside the papermaking mold to form a paper fiber laminate on the inner surface of the cavity. After the slurry is injected, pressurized air is injected to dehydrate the paper fiber laminate. The laminate is transferred to another drying mold, loaded into the drying mold, an elastic core is inserted inside the paper fiber laminate, and the paper fiber laminate is pressed from the inside with the core. It can be manufactured by heating the paper fiber laminate with the drying type heating means. Also,
It can also be manufactured by other manufacturing methods used for manufacturing this type of container.

Next, as shown in FIG. 2, a parison 30 is placed in the outer container 2 thus manufactured at the open end 20.
And fitted to the open end 20 so as to cover the open end 20 with the flange 30a. The swelling portion is swelled, and the swelling portion and the flange portion 30a form an opening end 2.
Since the outer container near zero can be clamped, the outer diameter of the bulging portion 31 can be made somewhat smaller than the inner diameter of the opening end 20. Then, hot air of a predetermined temperature is blown into the parison 30 to cause the bulging portion 31 of the parison 30 to bulge and adhere to the inner surface of the outer container 2. In this state, as shown in FIG.
0a, and the outer peripheral surface 22b of the mouth and neck 22 is also covered by the peripheral wall 30b, so that the open end 20 of the outer container 2 is not exposed to the outside. The mouth and neck 22 of the outer container 2
Is sandwiched between the peripheral wall portion 30b of the flange portion 30a and the bulging portion 31, and both are firmly integrated.

As described above, the composite container 1 of the present embodiment is
Since the peripheral wall portion 30b of the flange portion 30a and the bulging portion 31 can clamp the vicinity of the opening end of the outer container 2, sufficient strength can be obtained even if the bulging portion 31 of the parison 30 is bulged thin. Further, the outer diameter of the parison 30 before the bulging portion 31 bulges is adjusted to the opening end 2 which is the insertion port of the parison 30.
Even if it is slightly narrower than the inner diameter of the
When the outer container 2 is expanded, the outer container 2 can be sandwiched between the expanded portion 31 and the peripheral wall portion 30b of the flange portion 30a. Also, since the open end 20 of the outer container 2 is covered with the flange portion 30a of the parison 30, the open end 20 is not exposed to the outside. Accordingly, the outer container 2 is hard to be damaged at the opening end portion 20 and is an easy-to-use container excellent in design.

FIG. 3 shows a composite container according to a second embodiment of the present invention. In the figure, the same reference numerals are given to parts common to the composite container of the first embodiment,
The description is omitted. Therefore, the description of the first embodiment is appropriately applied to the parts that are not particularly described.

The composite container 1 ′ of the present embodiment comprises an outer container 2
Has no mouth and neck, and the flange 3 of the parison 30
It has the same configuration as the composite container 1 of the first embodiment except that Oa has an inclined surface 30c that covers the outer surface of the shoulder 21 of the outer container 2 instead of the peripheral wall 30b.

As shown in FIG. 4, the composite container 1 'of the present embodiment has an outer container opening end 2 inside an outer container 2 manufactured in the same manner as in the composite container 1 of the first embodiment.
The parison 30 is inserted from 0, and the parison 30 is arranged so as to cover the opening end 20 with the flange portion 30a. And parison 30
Hot air is blown into the inner space of the outer container 2 so that the bulging portion 31 of the parison 30 bulges. In this state,
As shown in FIG. 3, the open end 20 of the outer container 2 is covered with the inclined surface 30c of the flange 30a.
The shoulder portion 21 near zero is sandwiched between the inclined surface 30c of the flange portion 30a and the bulging portion 31, and both are firmly integrated.

In the composite container 1 'of this embodiment, similarly to the composite container 1 of the first embodiment, the shoulder portion 21 of the outer container 2 can be held by the flange portion 30a and the bulging portion 31 of the parison 30. Even if the bulging portion 31 of the parison 30 bulges thin, sufficient strength can be obtained. Further, even if the outer diameter of the bulging portion 31 of the parison 30 before bulging is slightly smaller than the inner diameter of the opening end 20 which is the insertion port of the parison 30, the bulging portion 31 is bulged thereafter. Thereby, the shoulder portion 21 can be held between the bulging portion 31 and the inclined surface 30c, so that the handleability during manufacturing is excellent. In addition, parison 3
Since the open end 20 of the outer container 2 is covered with the zero flange portion 30a, the open end 20 is not exposed to the outside. Accordingly, the outer container 2 is hard to be damaged at the opening end portion 20 and is an easy-to-use container excellent in design.

The composite container of the present invention is not limited to the above embodiment, and can be appropriately changed without departing from the spirit of the present invention. For example, a thread can be formed on the upper outer peripheral surface of the parison so that the cap can be screwed on.

In the above-described embodiment, one inner container is disposed inside the outer container. However, a multilayer inner container may be formed by forming the bulging portion of the parison in a multilayer structure. it can.

The composite container of the present invention is particularly suitable as a container for storing liquid detergents, liquid shampoos, rinses, liquid foods, edible oils, beverages, cosmetics and the like.

[0026]

According to the present invention, sufficient strength can be obtained even if the bulging portion of the parison is bulged thin, and the outer container is less likely to be damaged at the opening end, and has excellent design. An easy composite container is provided.

[Brief description of the drawings]

FIG. 1 is a judgment view showing a first embodiment of a composite container of the present invention.

FIG. 2 is a longitudinal sectional view showing a state in a manufacturing process of the composite container of the embodiment.

FIG. 3 is a judgment view showing a second embodiment of the composite container of the present invention.

FIG. 4 is a longitudinal sectional view showing a state in a manufacturing process of the composite container of the embodiment.

[Explanation of symbols]

 1, 1 'composite container 2 outer container 20 open end 21 shoulder 22 mouth and neck 22a outer peripheral surface 3 inner container 30 parison 30a flange 30b peripheral wall 30c inclined surface 31 bulge

Claims (5)

[Claims] 1. An outer container made of paper formed by a pulp molding method, and an inner container made of a thermoplastic resin blow-molded in the outer container, wherein the outer container faces an opening end. A composite container having a tapered shoulder, wherein the inner container swells a bulge portion of a parison made of a thermoplastic resin disposed at the opening end and is integrated with the outer container. The parison has a flange portion covering the open end, the outer container is sandwiched between the flange portion and the bulging portion, and the thickness of the bulging portion is 30 to 300 μm. A composite container characterized by the above. 2. The composite according to claim 1, wherein the outer container has a mouth and neck portion connected to the shoulder portion, and the flange portion has a peripheral wall portion covering an outer peripheral surface of the mouth and neck portion. container. 3. The composite container according to claim 1, wherein said flange portion has an inclined surface covering an outer surface of said shoulder portion. 4. The composite container according to claim 1, wherein said parison is made of polypropylene, polyethylene or polyethylene terephthalate. 5. The composite container according to claim 1, wherein low molecular weight polyethylene is added to said parison.