JP2001031139A - Composite container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent creases from generating between a molded body and an inner bag by using an article molded into a three-dimensional shape as the inner bag in a composite container produced by a method wherein the inner bag is inserted in a pulp mold molded body and the inner bag is drawn and the inner bag is brought into intimate contact with the inner face of the molded body. SOLUTION: In producing a composite container, at first, a mold 3 is made under an opening condition and two sheets of films 4 and 4 are arranged between both split molds 2 and 2. Then, both split molds 2 and 2 are closed and the films 4 are trimmed into a specified shape by means of a heater and a bag 5 is formed by applying heat sealing. Then, the inside of the mold 3 is made to be negative pressure by a suction means and a pressurized fluid is pressed into the bag 5 to bring the bag 5 into intimate contact with the inner face of a cavity 6 of the mold 3 and to mold the bag 5 into an inner bag 8 with a three-dimensional shape. Thereafter, the inner bag 8 is shrunk on its diameter and deformed and this is inserted into a pulp mold molded body 9 placed in another mold 10 and the inner bag 8 is drawn again and a composite container 1 is completed by bringing the inner bag 8 into intimate contact with the inner face of the molded body 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite container in which an inner bag is brought into close contact with an inner surface of a pulp molded article and a method for producing the same.

[0002]

2. Description of the Related Art As a composite container in which an inner bag is adhered to the inner surface of a pulp molded article, for example, the one described in Japanese Utility Model Laid-Open No. 6-20273 is known. In the composite container described in this publication,
The flat inner bag is inserted into the molded body, and the inserted inner bag is brought into close contact with the inner surface of the molded body.

However, in the above-mentioned composite container, wrinkles are apt to be generated when the inner bag is brought into close contact with the inner surface of the molded article. Since a part is easily thinned, the adhesion between the molded body and the inner bag may not be sufficient.

Accordingly, an object of the present invention is to provide a composite container in which wrinkles between a molded article and an inner bag are prevented. Another object of the present invention is to provide a composite container in which the inner bag is stretched uniformly, and the inner bag has a uniform thickness and is in close contact with the inner surface of the molded article.

[0005]

According to the present invention, an inner bag is inserted into an inside of a pulp molded article having an opening, and the inner bag is stretched by inserting the inner bag into the inner surface of the molded article. The object has been achieved by providing a composite container in which a three-dimensionally shaped inner bag is used as the inner bag in a composite container having an inner bag adhered thereto.

The present invention also provides a method of manufacturing the composite container, wherein the inner bag is inserted into the pulp molded article having an opening through the opening, and the inner bag is stretched. In the method for producing a composite container in which the inner bag is closely attached to the inner surface of the body, the inner surface area of the molded body is A, the outer surface area of the inner bag is B, and the inner sectional area C of the upper end of the opening of the molded body is C. An object of the present invention is to provide a method for producing a composite container in which the inner bag is inserted into and adhered to the inside of the molded article under conditions satisfying the following formulas (1) and (2). 0.5A ≦ B <A (1) 0 <C ≦ A / 5 (2)

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a composite container according to the present invention will be described below with reference to the drawings together with a preferred method of manufacturing the same.

FIGS. 1A and 1B are a schematic front view and a sectional view taken along line AA of a split mold 2 used in a preferred method of manufacturing a composite container according to an embodiment of the present invention. It is shown. The split molds 2 form a set of two pieces and constitute an inner bag forming mold described later. Split mold 2 is 3 in the vertical direction
It is divided and divided into three parts,
a, the middle part 2b and the lower part 2c are assembled and fixed.

The split mold 2 has a molding surface 21 for the inner bag. The molding surface 21 has a concave shape. The molding surface 21 has a through hole 2 penetrating from the front surface to the back surface over the entire surface.
2 are formed in large numbers. A flat outer edge 23 extending outward and horizontally from the periphery of the molding surface 21 is formed. The periphery of the outer edge 23 is rectangular in plan view. In the outer peripheral portion 23, a cutout portion 24 of a film described later is formed. The cutout portion 24 is similar to a parison cutter in a mold for blow molding a plastic molded product.

In the upper part 2a of the split mold 2, a heater 25 is provided.
a is arranged. The heater 25a is formed of a rod-shaped heating element, which is formed in an arc shape. Also, the middle part 2b
Another heater 25b is provided in the lower part 2c.
The heater 25b is also formed of a rod-shaped heating element, and has a shape substantially similar to the shape of the cutout portion 24. Heater 2
A heat insulator 26 is provided between the molding surface 5b and the molding surface 21 so that the heat of the heater 25b is not directly supplied to the molding surface 21. This makes it possible for the film to be described later to be cut off and heat-sealed, and to prevent the film from being fused to the molding surface 21. In actual use, the molding surfaces 21 in the middle portion 2b and the lower portion 2c may be cooled to a predetermined temperature in order to prevent the fusion.

Next, a preferred method of manufacturing a composite container according to an embodiment of the present invention using the split mold 2 will be described with reference to FIG. The composite container of the present embodiment is one in which an inner bag is closely attached to the inner surface of a bottle-shaped pulp molded article.

First, an inner bag is formed by the procedure shown in FIGS. 2 (a) to 2 (c). In this procedure, the inner bag forming mold, which is composed of a set of split dies and in which a cavity of a predetermined shape is formed by assembling the split dies, is kept in an open state, and the split mold in the open state is opened. After disposing the two films in a state of being overlapped therebetween, closing the mold, sandwiching the film between the split molds, trimming the film into a predetermined shape, and heat-sealing the vicinity of the trimmed portion. After forming a bag on a flat surface, the inner bag forming die is suctioned toward the outside by a predetermined suction means, and a predetermined pressurized fluid is press-fitted into the flat bag,
A three-dimensional inner bag having an opening is formed by closely contacting the bag on the plane with the inner surface of the cavity of the inner bag molding die, and simultaneously with or before or after the close contact with the opening. A ring-shaped member is inserted, and the opening and the ring-shaped member 7 are fixed by predetermined means.

More specifically, as shown in FIG. 2 (a), the inner bag forming mold 3 which is a set of two split dies 2, 2 is kept open, The two films 4 and 4 are arranged in a state of being overlapped between the two. The heater 25b in each of the split molds 2 and 2 is heated to a predetermined temperature so that the film 4 is cut off and heat-sealed at the cutout portion 24. The heating temperature depends on the type of the resin constituting the film 4, but when the melting point of the resin is Tm ° C, (Tm + 5) to (Tm + 100) ° C, particularly (Tm + 10)
To (Tm + 50) ° C.

The inner bag forming mold 3 has a cavity of a predetermined shape formed by bringing two split dies 2 and 2 into contact with each other at their divided surfaces. The shape of the cavity is
The shape is substantially similar to the inner shape of the pulp molded article constituting the composite container.

Next, as shown in FIG. 2B, the split molds 2 and 2 are closed, and the films 4 and 4 are sandwiched between the split molds 2 and 2. As described above, the cut-off portions 24 of the film 4 are formed in the split molds 2 and 2.
The heater 25b located in the vicinity is heated to a predetermined temperature. Therefore, by closing the split molds 2 and 2, the films 4 and 4 are trimmed into a predetermined shape by the cut-off portions, and the cut-off portions and the vicinity thereof are heat-sealed. As a result, a flat bag 5 is formed in which the two films 4 and 4 are superposed and the outer edges are heat-sealed.

In this state, the inner bag forming mold 3 is sucked toward the outside by a predetermined suction means (not shown), and a predetermined pressurized fluid, for example, Inject air. As a result, the flat bag 5 comes into close contact with the inner surface of the cavity 6 of the inner bag forming die 3.

As described above, since the split molds 2 and 2 are heated to a predetermined temperature, the shape of the cavity 6 is formed by the heating on the bag 5 in a state of being in close contact with the inner surface of the cavity 6. 5 is formed into a three-dimensional inner bag having an opening. As described above, since the shape of the cavity 6 is substantially similar to the inner shape of the pulp molded article constituting the composite container, the shape of the molded inner bag is also the inner shape of the pulp molded article constituting the composite container. And a similar shape.

In the molded inner bag, when the inner surface area of the pulp molded article is A, the outer surface area of the inner bag is B, and the inner cross-sectional area C at the upper end of the opening of the pulp molded article, the following equation (1) is obtained. ) And (2) are preferably satisfied.

0.5A ≦ B <A (1) 0 <C ≦ A / 5 (2)

More specifically, in the above formula (1), B is 0.
If it is less than 5 A, it is difficult to make the film 4 adhere to the inner surface of the pulp molded article. Equation (1) is
More preferably, they are represented by the following formulas (1) ′ and (1) ″.

0.7A≤B <A (1) '0.8A≤B <A (1) "

When the inner bag is formed, the ring-shaped member 7 is inserted into the inner bag from the opening of the cavity 6, and the ring-shaped member 7 is mounted on the opening of the inner bag. Upper part 2a in split mold 2
Is not provided with a heat insulator, and the heat of the heater 25a is sufficiently transmitted, so that the inner bag and the ring-shaped member 7 are thermally fused by heating. The ring-shaped member 7 is made of plastic, is fitted into the opening of the pulp molded article, and is used to reinforce the opening.

When the forming of the inner bag and the attachment of the ring-shaped member 7 to the inner bag are completed, the suction of the inner bag forming mold 3 is stopped,
The mold halves 2 and 2 are opened, and the inner bag 8 with the ring-shaped member 7 attached to the opening is taken out as shown in FIG. 2 (c).

The material constituting the inner bag 8 (film 4) is not particularly limited, and various thermoplastic resins can be used. From the viewpoint of improving the water resistance and the like of the obtained composite container and preventing deterioration of the content filled in the composite container, the material is preferably liquid-impermeable and low in moisture permeability. For example, when the contents of the liquid are filled, the components in the liquid volatilize after long-term storage and the content decreases,
Further, when the content of the powder is filled, moisture and the like may enter from the outside after storage for a long time to increase the content (the degree of such decrease or increase of the content is referred to as volatility).
From this viewpoint, the moisture permeability of the inner bag 8 is in accordance with JIS Z0208.
Is 0 to 4 g / (m ² · 24h
r), particularly preferably 0 to ² g / (m ² · 24 hr).

In order to keep the moisture permeability within the above range, it is preferable that the inner bag 8 (film 4) contains a polyolefin resin having a cyclic olefin as a polymerization component. In particular, it is preferable that the inner bag 8 (film 4) has a multilayer structure, and any one of the layers contains a polyolefin resin having a cyclic olefin as a polymerization component. In the case of a multilayer structure, the polyolefin-based resin is preferably contained in a layer other than the innermost layer, and more preferably the polyolefin-based resin is contained in an outermost layer (that is, a layer that is in close contact with the inner surface of the molded article). .

Heavy synthesis of the polyolefin resin
Examples of cyclic olefins as
(2.2.1) Hept-2-ene or a derivative thereof, tet
Lacyclo (4.4.0.1^2,5. 1^17,10) -3-Dode
Sen or its derivative, hexacyclo (6.6.1.1)
^3,6. 1^10,13. 0^2,7. 0^9,14) -4-Heptadecene
Or a derivative thereof, octacyclo (8.8.0.1^2,9.
1^4,7. 1^11,10. 1^13,16. 0^3,8. 0^12,17) -5
-Dococene or a derivative thereof, pentacyclo (6.6.
1.1^3,6. 0^2,7. 0^9,14) -4-hexadecene or
Its derivative, pentacyclo (6.5.1.1)^3,6. 0
^2,70^9,13) -Pentadecene or a derivative thereof, Heptasi
Black (8.7.0.1^2,9. 1^4,7. 1^11,16.
0^3,8. 0^12,16) -5-Henoeicosene or its induction
Body, tricyclo (4.4.0.1^2,5) -3-Undesse
Or its derivative, tricyclo (4.3.0.1^2,5)
-3-decene or a derivative thereof, pentacyclo (6.5.
1.1^3,6. 0^2,7. 0^9,13) -4,10-Pentadeca
A diene or a derivative thereof, pentacyclo (4.7.0.1
^2,5. 0^8,13. 1^9,12) -3-Pentadecene or its induction
Conductor, heptacyclo (7.8.0.1 ^3,6. 0^2,7. 1
^10,17. 0^11,16. 1^12,15) -4-eicosene or its
Derivatives of nonacyclo (9.1.1.1.1)^4,7.
0^3,8. 0^2,10. 0^12,21. 1^13,20. 0^14,19. 1
^15,19) -5-Pentacecon or a derivative thereof, and the like.
It is. The polyolefin-based resin is a cyclic olefin resin.
Or a homopolymer or copolymer of
Or one or more of the cyclic olefins,
Ethylene, propylene, 1-butene, 1-pentene, 4
-Methyl-pentene, 3-methyl-pentene, 1-hexyl
Sen, 1-heptene, 1-octene, 1-nonene or 1
-It may be a copolymer with an olefin such as decene.

When the polyolefin resin is a copolymer containing the cyclic olefin as a copolymer component,
The structural unit derived from the cyclic olefin is preferably 5 to 60 mol%, particularly preferably 20 to 50 mol%, and the structural unit derived from the olefin other than the cyclic olefin is 40 to 95 mol%, particularly 50 to 80 mol%. %.

The layer containing the polyolefin resin may be composed of only the polyolefin resin.
Alternatively, a blend of the polyolefin-based resin with a linear low-density polyethylene, a low-density polyethylene, an ionomer, an amorphous polyolefin, or the like may be used. The ratio of the polyolefin-based resin in this blend is 5% in view of the insertability of the inner bag 8, the vacuum formability of the inner bag 8, the gas barrier property of the inner bag 8, and the functionality in FIG. ~
It is preferably 70% by weight, particularly preferably 8 to 33% by weight.

The entire thickness of the inner bag 8 including the layer containing the polyolefin resin is 15 to 200 μm, particularly 100 μm.
It is preferably from 150 to 150 μm.

The resin constituting layers other than the layer containing the polyolefin resin in the inner bag 8 having a multilayer structure includes linear low density polyethylene, low density polyethylene, high density polyethylene, ethylene-propylene copolymer, ethylene -Vinyl acetate copolymers, ethylene-vinyl alcohol copolymers, ethylene-acrylate copolymers and the like are preferably used.

In order to form the inner bag 8 into a multilayer structure, for example, a method of simultaneously extruding a resin constituting each layer using an extruder,
A known method such as a method of manufacturing each layer separately and bonding each layer with an adhesive is used.

After the formation of the inner bag 8, the inner bag 8 is brought into close contact with the inner surface of the pulp molded article. This state is shown in FIGS. 2D and 2E. Specifically, as shown in FIG. 2D, a bottle-shaped pulp molded article 9 having an opening, which has been molded in another step in advance, is divided into two split molds 11,
At 11, the mold is loaded into the cavity 12 of the composite container manufacturing mold 10 which forms a set. The shape of the cavity 12 is
It is made in the same way as the external shape. Each of the split dies 11, 11 is previously heated to a predetermined temperature. The heating temperature is (Tm + 5) when the melting point of the resin is Tm ° C. in consideration of the type of resin constituting the film 4 and the prevention of thermal damage to the molded body 9.
(Tm + 100) ° C, especially (Tm + 10) to (Tm + 50) ° C
It is preferable that

At the same time, as shown in FIG. 2 (d), the inside of the inner bag 8 is evacuated to a vacuum to reduce its volume, and to be in a slender state to pass through the opening 9a of the molded body 9. . Then, the inner bag 8 in the elongated state is inserted into the opening 9 a of the molded body 9.
And the ring member 7 attached to the opening of the inner bag 8 is fitted into the opening 9a of the molded body 9. In this case, it is preferable that the inner bag 8 is inserted into the molded body 9 under the conditions satisfying the above-mentioned expressions (1) and (2).

Next, as shown in FIG. 2 (e), the composite container manufacturing mold 10 is sucked toward the outside and a pressurized fluid such as air is placed in the inner bag 8 inserted into the molded body 9. Supply. Since the molded body 9 has a certain degree of air permeability, the inner bag 8 is stretched and adhered to the inner surface of the molded body 9 by the suction and the supply of the pressurized fluid. In this case, as described above, since the inner bag 8 is substantially similar to the inner shape of the molded body 9,
The inner bag 8 is stretched almost uniformly at any of the portions, and adheres to the inner surface of the molded body 9. In addition, since each of the split molds 11 constituting the composite container manufacturing mold 10 is heated to a predetermined temperature, the inner bag 8 in a state of being in close contact with the inner surface of the formed body 9 is softened or melted to form the formed body. 9 is adhered more closely to the inner surface.

When the inner bag 8 is brought into close contact with the inner surface of the molded body 9, the inner bag 8 is stretched at a predetermined stretching ratio. Slightly smaller.

When the inner bag 8 is sufficiently adhered to the inner surface of the molded body 9, the suction of the composite container manufacturing mold 10 and the supply of the pressurized fluid into the inner bag 8 are stopped. Next, as shown in FIG. 2 (f), the split molds 11, 11 are opened to take out the composite container 1 as an object.

The composite container 1 obtained as described above has the inner bag 8 in close contact with the inner surface of the molded body 9 and therefore has high water resistance and low moisture permeability. As a result, when the composite container 1 is filled with a liquid, the liquid leakage is effectively prevented, and when the composite container 1 is filled with a powder, entry of moisture from the outside is effectively prevented. Also, since the molded body 9 and the inner bag 8 are in close contact with an appropriate strength, when the composite container 1 is discarded, both can be easily separated from each other, and can be separated and disposed efficiently. Furthermore, since the plastic ring member 7 is attached to the opening that is loaded when the composite container 1 is used, the composite container 1 can sufficiently withstand repeated use.

The present invention is not limited to the above embodiment. For example, when the inner bag 8 is brought into close contact with the inner surface of the molded body 9, the distance between the inner bag 8 and the molded body 9 is within a range that does not make it difficult to separate the inner bag 8 and the molded body 9 when discarding the composite container 1. May be provided with an adhesive.

Depending on the use of the composite container 1, FIG.
Instead of forming a screw portion 9b on the outer surface of the opening 9a of the molded body 9 as shown in FIG. 3A, or forming the screw portion 9b on the outer surface of the opening 9a as shown in FIG. Alternatively, a screw portion 7a may be formed on the outer surface of the ring member 7.

[0040]

The present invention will be described in more detail with reference to the following examples.

Examples 1 to 11 Using the films of the materials shown in Table 1, the inner bag was formed into a three-dimensional shape by the method shown in FIG. In the mold for forming the inner bag, the upper part was heated to 140 ° C., and the molding parts at the middle and lower parts were cooled to 15 ° C. The shape of the inner bag was substantially similar to the inner shape of a bottle-shaped pulp molded article having an opening formed separately. A plastic ring member was attached to the opening of the inner bag, and the ring member and the inner bag were heat-sealed.
Table 1 shows the thickness and moisture permeability of the inner bag. Also, the outer surface area B of the inner bag and the inner surface area A of the pulp molded product
Table 1 also shows the inner cross-sectional area C of the upper end of the opening. Then
The pulp molded article was loaded into a composite container manufacturing mold heated to 150 ° C., the inner bag was stretched by the method shown in FIG. 1, and the pulp molded article was brought into close contact with the inner surface of the molded article to obtain a composite container. Was.

[Comparative Examples 1 and 2] Two sheets of the same film as in Example 1 were overlaid, and a predetermined portion was heat-sealed to produce a flat inner bag. Next, the inner bag was adhered to the inner surface of the molded body in the same manner as in Example 1 to obtain a composite container.

[Evaluation of Performance] With respect to the composite containers obtained in Examples and Comparative Examples, the state of close contact between the molded body and the inner bag was observed visually or by tentacles, and evaluated according to the following criteria. Table 1 shows the results. <Evaluation criteria> ・: No partial floating is observed in the inner bag. ×: Partial floating is observed in the inner bag.

The volatility of the contents of the composite containers obtained in Examples and Comparative Examples was evaluated by the following method.
Table 1 shows the results. <Evaluation of volatility> The contents were filled in a composite container at 40 ° C.
After storage for 6 months in an environment of 75 RH%, it was evaluated as "O" when the volatilization rate was within ± 30% of the content, and as "X" otherwise.

[0045]

[Table 1]

As is evident from the results shown in Table 1, the composite container of the present invention (the product of the present invention) in which a three-dimensionally shaped inner bag is used as the inner bag is a comparative example using a flat inner bag. It can be seen that the adhesion between the molded body and the inner bag is better than that of the composite container of the example.

[0047]

According to the present invention, it is possible to provide a composite container in which wrinkles between the molded body and the inner bag are prevented, and the adhesion between the molded body and the inner bag is excellent. Further, according to the present invention, there is provided a composite container in which the inner bag is uniformly stretched, and the inner bag has a uniform thickness and is in close contact with the inner surface of the molded body. Further, in the composite container of the present invention, since the molded body and the inner bag are in close contact with an appropriate strength, both can be easily separated after use, and can be separated and disposed efficiently.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are respectively a schematic front view and a cross-sectional view taken along the line AA of a split mold used in a preferred method of manufacturing a composite container according to an embodiment of the present invention. .

FIG. 2 is a schematic view showing a preferred method for producing a composite container according to one embodiment of the present invention.

FIG. 3 is an enlarged view of a main part showing another embodiment of the composite container of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Composite container 8 Inner bag 9 Pulp molded article

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toshio Kobayashi 2606 Kabane-cho Akabane, Haga-gun Tochigi Pref. 72) Inventor Osamu Nakata 2606 Akabane, Kaigamachi, Haga-gun, Tochigi Pref. SG05 SH18 SJ01 SJ21 SK06 SP12 SP17 SP22

Claims (5)

[Claims] 1. A composite obtained by inserting an inner bag into a pulp molded article having an opening through the opening and stretching the inner bag to bring the inner bag into close contact with the inner surface of the molded article. In the container, a composite container using a three-dimensionally formed one as the inner bag. 2. The composite container according to claim 1, wherein a ring member is attached to an opening of the inner bag, and the ring member is in close contact with the inner surface of the molded body together with the inner bag. 3. The thickness of the inner bag is 15 to 200 μm,
The composite container according to claim 1, wherein the moisture permeability is 0 to 4 g / (m ² · 24 hr). 4. The composite container according to claim 1, wherein the inner bag has a multilayer structure, and any one of the layers contains a polyolefin resin having a cyclic olefin as a polymerization component. 5. A composite container in which an inner bag is inserted through an opening into a pulp molded article having an opening, and the inner bag is stretched to bring the inner bag into close contact with the inner surface of the molded article. In the manufacturing method, when the inner surface area of the molded body is A, the outer surface area of the inner bag is B, and the inner sectional area of the upper end of the opening of the molded body is C, the following formulas (1) and (2) A method for producing a composite container in which the inner bag is inserted into and tightly adhered to the inside of the molded body under conditions satisfying the following. 0.5A ≦ B <A (1) 0 <C ≦ A / 5 (2)