JP4128174B2 - Composite container - Google Patents

Description

  The present invention relates to a composite container in which an inner layer container and an outer layer container are combined.

As a conventional technique related to a composite container in which an inner layer container and an outer layer container are combined, for example, the containers of Patent Documents 1 and 2 below are known.
The container described in Patent Document 1 is provided with a heat insulating member on the outside of the container main body so that it is fitted at the upper portion of the trunk, and a gap is provided between the container main body and the heat insulating member to provide heat insulating properties. It is a thing. Moreover, the container of patent document 2 is a pulp mold container which covered the outer side of the inner container with the outer shell, and made the outer shell pulp density lower than the density of the pulp of the inner container to impart heat insulation.

  By the way, since the container of patent document 1 has a clearance gap in the trunk | drum, the intensity | strength of the container had to become low. Further, in order to improve the strength, there is a possibility that the container may be cracked when a film is applied to the inner surface of the container body by vacuum forming, or the container may be crushed by the printing pressure when printing on the outer surface of the container. On the other hand, although the technique described in Patent Document 2 has heat insulation properties, the outer shell has a low density, so the surface properties of the outer surface are poor and the dimensional accuracy is low.

Japanese Patent Laid-Open No. 11-301753 JP 2002-128075 A

  The present invention has been made in view of the above problems, and has excellent heat insulating properties, surface properties, and dimensional accuracy of the outer shape, and is a composite having excellent strength, particularly strength against a longitudinal compressive load and deformation resilience due to the compressive strength. The purpose is to provide a container.

The present invention is a composite container in which an inner layer container and an outer layer container each made from a raw material containing pulp are combined, and the inner dimension of the body part of the outer layer container is outside the body part of the inner layer container. The inner layer container and the outer layer container have a fitting margin that overlaps when the inner layer container and the outer layer container are virtually overlapped, and the inner layer container is more elastic than the outer layer container. The object is achieved by providing a composite container having a low rate and having a corner radius of curvature Ro on the outside of the bottom of the composite container of 5 mm or less.

  ADVANTAGE OF THE INVENTION According to this invention, while being excellent in heat insulation, surface property, and the dimensional accuracy of an external shape, the composite container excellent in intensity | strength, especially the intensity | strength with respect to a vertical compressive load, and the decompression | restoration property of the deformation | transformation by this compressive strength is provided.

  The present invention will be described below based on preferred embodiments with reference to the drawings.

  FIG. 1 shows an embodiment in which the composite container of the present invention is applied to a food container such as instant cup noodles. In FIG. 1, the code | symbol 1 has shown the composite container.

  As shown to Fig.1 (a), the composite container 1 is the thing by which the inner-layer container 2 and the outer-layer container 3 which were each made from the raw material containing a pulp were compounded and integrated.

  In the composite container 1, the elastic modulus of the inner layer container 2 is lower than the elastic modulus of the outer layer container 3. The ratio of the elastic modulus of the inner layer container 2 and the outer layer container 3 is preferably 1/2 to 1/20 of the outer layer container. The elastic modulus of the inner layer container 2 is preferably 100 to 2000 MPa, and more preferably 200 to 1500 MPa. The elastic modulus of the outer layer container 3 is preferably 200 to 10,000 MPa, more preferably 400 to 6000 MPa, and still more preferably 600 to 4000 MPa. Here, the elastic modulus of inner layer container 2 and outer layer container 3 is Rheometrics manufactured by Rheometrics, model SOLIDS ANALYZER RSAII, measurement conditions are frequency 1.6HZ / 0.05% strain, standard conditions specified in JISP8111, pretension is The dynamic force is twice, the sample width is 6 mm, the sample length is 35 mm, and the sample thickness is 0.86 mm. The sample is measured by cutting the body of the container in the height direction. The elastic moduli of the inner layer container and the outer layer container can be appropriately set by adjusting the material composition and the pressure applied during molding.

  The composite container 1 has a radius of curvature Ro (see FIG. 1 (d)) of 5 mm or less at the outer side of the bottom part 14 (outer layer container 3). As a result of the study by the present inventors, the inner layer container 2 having a low elastic modulus (low density) as described above and the outer layer container 3 having a higher elastic modulus (high density) than that are combined, and a radius of curvature Ro. When the thickness is 5 mm or less, it has been found that the displacement when receiving a vertical compressive load can be kept small, and that the high resilience of the displacement when the compressive load is solved is expressed. That is, when the composite container 1 receives a vertical compressive load, the deformation of the inner layer becomes a secondary deformation from the outer layer, so the deformation of the inner layer is smaller than the deformation of the outer layer, but the outer layer has a high elastic modulus. Since the elongation is small and the inner layer has a low elastic modulus and a large elongation, the inner layer acts to assist the restoration of deformation, and a restoring property superior to the restoring properties of the inner layer and the outer layer can be obtained. This effect is more remarkable particularly when the radius of curvature is in a specific range, and the radius of curvature Ro is preferably 0.5 to 3 mm, and more preferably 0.5 to 2 mm. Here, the vertical compressive load refers to a vertical load in a state where the container is erected in a horizontal position.

  As will be described later, the composite container 1 is combined with an inner container 2 fitted into an outer container 3. When the inner layer container 2 and the outer layer container 3 are fitted and combined, the strength of the composite container 1 including the strength against the vertical compressive load described later and the resilience of deformation due to the compressive load are further improved. Here, the fitting means that when the inner layer container 2 and the outer layer container 3 are combined, pressure is applied to the body parts of both containers, and the body parts of both containers are crushed by the collapse of the body parts of at least one container. In this state, stress such as compression and tension is generated, and a frictional force is generated between the two containers.

Hereinafter, the composite container 1 will be further described in detail.
The composite container 1 has a flange portion 11 at the peripheral edge portion of the mouth portion 10. The width W11 of the upper surface portion (flat portion) 110 of the flange portion 11 shown in FIG. 1B is preferably 1.0 to 5 mm, particularly preferably 1.5 to 4 mm. By setting the width W11 within such a range, a decrease in strength of the flange portion 11 can be suppressed, and when the lid is attached, a bonding area where good bonding strength and sealing properties can be obtained can be secured.

  Thickness (all layer thickness) T11 of the flange portion 11 prevents deformation of the mouth when the container is held by hand (ensures gripping strength), prevents deformation of the flange when the lid is attached and peeled off, thin and lightweight In view of the properties and the good mouth feel during use, it is preferably 0.8 to 5 mm, particularly preferably 1.0 to 3.5 mm.

  The composite container 1 has a portion in which the total layer thickness differs in the vertical direction in the body portion 12.

Thickness T121 in the vicinity of the mouth portion of the body portion 12 is prevention of deformation of the mouth portion (gripping strength) when the container is held by hand, prevention of buckling in the vicinity of the mouth portion of the body portion 12 due to a longitudinal load, thinness, lightness, etc. Is considered to be 0.8 to 3.5 mm, particularly 0.9 to 2.6 mm.
The thickness T122 in the central portion of the body portion 12 is preferably 0.7 to 3 mm, particularly preferably 0.8 to 2.2 mm in consideration of heat insulation properties, thinness / lightness, and the like.
The thickness T123 in the lower part of the body 12 is preferably 0.7 to 4 mm, particularly preferably 0.8 to 3.1 mm in consideration of securing the thickness necessary for the stack step and the strength, heat insulation, thinness, lightness, etc. of the stack. . In the present specification, the vicinity of the mouth portion of the body portion 12 refers to a portion of 0 to 20% from the upper surface portion 110 of the flange portion 11 with respect to the height H of the composite container 1. The lower part of the body part 12 is a part from the stacking step 13 to the bottom surface. The center part of the trunk | drum 12 means the part between the said mouth part vicinity part and the said lower part.

  In the composite container 1, a stacking step 13 is formed in the body portion 12. For this reason, the composite container 1 after molding can be easily loaded and separated. Below the stack step 13, the thickness of the body portion is thin. For this reason, when forming a coating layer on the inner surface of the composite container 1 by vacuum forming, the inner layer container 2 can be prevented from being kinked and broken.

  The taper angle θ1 (see FIG. 1 (c)) of the body portion 12 of the composite container 1 is determined in consideration of ease of use as a container, internal volume, moldability, the aforementioned loading after molding, ease of separation, and the like. It is preferably 3 to 10 degrees, particularly 5 to 8 degrees. The taper angle θ2 (see FIG. 1 (d)) of the inner surface of the body portion below the stacking step 13 is ruptured when the inner layer container 2 is kinked when the container is thin, lightweight, and the cover layer is formed by vacuum forming. In consideration of preventing this, it is preferably set to 2 to 9 degrees, particularly 4 to 7 degrees. Moreover, it is preferable that θ1> θ2.

  As shown in FIG. 1 (d), the composite container 1 has a raised bottom portion 141 in which the central portion of the bottom portion 14 is raised to a predetermined height, and has a flat grounding portion 142 on the outer side thereof. The thickness T14 of the bottom portion 14 is preferably 0.4 to 2.8 mm, particularly preferably 0.5 to 2 mm in consideration of heat insulation as a container, compression strength in the vertical direction, thinness / lightness, and the like.

  The grounding width W14 of the grounding part 142 of the bottom part 14 is preferably 1 to 20 mm, particularly 2 to 10 mm, and the height H14 of the raised bottom part 141 of the bottom part 14 is 0.5 to 5 mm, particularly 1 to 3 mm. Is preferred. By setting the ground contact width 14 in such a range, a ground contact area that receives a vertical compression load can be sufficiently secured. By setting the height H14 of the raised bottom portion 141 within such a range, the content of the inner surface corner portion does not enter without narrowing the inner volume of the container. In addition, the shape can be satisfactorily transferred by the male mold made of an elastic material described later on the corner portion having the radius of curvature and the bottom portion 14 having the ground contact width. Moreover, when the composite container 1 is packaged with a packaging material such as a shrink film, the packaging material can be easily broken. Further, by setting the radius of curvature Ro, the contact width W14 and the height H14 of the raised bottom portion 141 in such a range, as a synergistic effect thereof, the composite container 1 with sufficient longitudinal strength against the compressive load in the vertical direction can be provided. can get.

  In the composite container 1, an inclined surface 15 is formed at the opening edge of the mouth 10. An angle θ3 between the inclined surface 15 and the upper surface portion 110 of the flange portion 11 is preferably 30 to 75 degrees, particularly 45 to 70 degrees. Moreover, it is preferable that chamfering width is 0.5-3 mm. The chamfer width refers to W15 (see FIG. 1B). By setting the angle and the width of the inclined surface 15 in such a range, the formability of the corner portion of the opening edge is improved, and the surface property is improved. The pulp at the corner of the opening edge is pushed in at the time of molding, and the ridgeline that becomes the boundary of the inclined surface 15 becomes clear. Therefore, the appearance of the mouth portion 10 is improved, the density is increased, and the strength of the flange portion 11 is increased. improves. Further, fluffing of the pulp at the opening edge is suppressed, the adhesiveness when the coating layer is formed with a resin film or the like is improved, and the occurrence of pinholes when the coating layer is formed is suppressed. Moreover, the mouthfeel at the time of use also becomes favorable.

  Considering that the composite container 1 can be held by hand even with hot water and is thin and lightweight and has a desired strength, the heat insulation is preferably 45 to 75 ° C, particularly 50 to 70 ° C. . Here, the heat insulating property is that the temperature sensor (Anritsu 503K-TC-WT) measuring unit is attached to the outer surface of the composite container with tape, and hot water of 98 to 100 ° C. is poured into the composite container, and the container after 1 minute. It is determined by the external temperature.

  The composite container 1 has an air permeability of 30 to 30 considering that the coating layer is uniformly coated with a resin film or the like by vacuum forming or pressure forming, and preventing the occurrence of pinholes in the resin film or the like. It is preferably 120 seconds, particularly 40 to 60 seconds. The air permeability can be measured according to JIS P81170-1980, for example, using a measuring device (Tokyo Tester, Gurley's Desometer).

  When the composite container 1 is used for instant cup noodles as in the present embodiment, the inner diameter of the body 12 is 60 to 200 mm, preferably 50 to 150 mm. The height H is 60 to 200 mm, preferably 70 to 150 mm.

  The composite container 1 preferably has a total weight of 10 to 30 g, preferably 10 to 25 g, considering the balance of ease of disposal, cost reduction, ensuring strength, ensuring heat insulation, and the like.

  Hereinafter, each of the inner layer container 2 and the outer layer container 3 will be described in more detail.

  The inner layer container 2 is made of a pulp mold having a flange portion 21 and imparts heat insulation to the composite container 1 and cushioning to the flange portion 11.

  On the inner surface of the barrel portion 22 of the inner layer container 2, a step (not shown) that becomes the stacking step 13 and the hot water filling line 16 is formed.

  The thickness T21 (see FIG. 1 (b)) of the flange portion 21 of the inner layer container 2 constituting the flange portion 11 prevents the mouth portion from being deformed when the container is held by hand, and the flange when the lid is attached and peeled off. Considering strength, cushioning properties of the flange portion, thinness / light weight, good mouth feel, etc., 0.4 to 3 mm, particularly 0.5 to 2 mm is preferable. The thickness T221 of the body portion 22 of the inner container 2 constituting the vicinity of the mouth portion 10 of the body portion 12 is heat-insulating, preventing deformation of the mouth portion when the container is held by hand (ensuring grip strength), Considering prevention of buckling in the vicinity of the mouth portion of the body portion 12 when a compressive load is applied, thinness and lightness, etc., 0.55 to 2 mm, particularly 0.6 to 1.7 mm is preferable. The thickness T222 (see FIG. 1 (c)) of the body portion 22 of the inner container 2 constituting the center portion of the body portion 12 is 0.5 to 1.8 mm, particularly 0.55 to The thickness is preferably 1.5 mm. The thickness T223 (see FIG. 1 (d)) of the barrel portion 22 of the inner layer container 2 constituting the lower portion of the barrel portion 12 is heat-insulating, ensuring the thickness necessary for the step for stacking, and vacuum forming as described later. In the case of forming the coating layer, it is preferable to set the inner layer container 2 to 0.55 to 3 mm, particularly 0.65 to 2.5 mm in consideration of preventing the inner layer container 2 from being twisted and breaking, and considering the thin wall and lightness. The thickness T24 of the bottom portion 24 of the inner layer container 2 constituting the bottom portion 14 is preferably 0.3 to 1.8 mm, particularly preferably 0.4 to 1.5 mm in consideration of heat insulating properties, longitudinal compressive strength, thinness / lightness, and the like. In particular, by setting the thickness of the body portion within such a range, a desired contact force can be easily obtained when the inner layer container and the outer layer container are fitted as described later.

The elastic modulus of the body portion 22 of the inner layer container 2 including the fitting portion with the outer layer container 3 is such that when the inner layer container 2 and the outer layer container 3 are combined, the inner layer container is mainly crushed and the outer layer container is not bent. Considering that the inner layer does not break due to vacuum pressure during molding, it is preferably 100 MPa to 2000 MPa, more preferably 200 MPa to 1500 MPa, and further preferably 300 MPa to 1000 MPa. Further, the ratio of the elastic modulus of the inner layer container and the outer layer container in the fitting allowance portion is preferably 1/2 to 1/20 of the outer layer container.
Here, the elastic modulus of the body portion 22 of the inner layer container 2 is Rheometrics manufactured by Rheometrics, model SOLIDS ANALYZER RSAII, and the measurement conditions are the standard conditions specified in the frequency 1.6HZ / 0.05% strain, JIS P8111. Adopted, pre-tension is twice the dynamic force, sample width 6 mm, sample length 35 mm, sample thickness 0.86 mm, and the sample is measured by cutting the body of the container in the height direction. The elastic modulus of the inner layer container can be set as appropriate by adjusting the material composition, the applied pressure during molding, and the like.

The density of the inner layer container 2 is preferably 0.05 to 0.8 g / cm ³ , particularly preferably 0.1 to 0.8 g / cm ³ . By setting the density within such a range, the composite container 1 can be provided with good heat insulation properties, and the container weight can be reduced. In addition, the gripping strength and compressive strength of the composite container 1 can be improved. Here, in this specification, a density means a bulk density.

The density of the body portion 22 of the inner layer container 2 constituting the vicinity of the mouth portion 10 of the body portion 12 is the heat insulating property, the deformation of the mouth portion when the container is held by hand, and the mouth portion due to the compressive load in the vertical direction. Considering buckling prevention and the like, it is preferably 0.2 to 0.8 g / cm ³ , particularly 0.3 to 0.7 g / cm ³ .
The density of the body portion 22 of the inner layer container 2 constituting the central portion of the body portion 12 takes into consideration heat insulation, prevention of dent of the body portion when the container is held by hand, and prevention of deformation due to printing pressure during printing. 0.05 to 0.5 g / cm ³ , particularly preferably 0.1 to 0.4 g / cm ³ .
The density of the barrel portion 22 of the inner layer container 2 constituting the lower portion of the barrel portion 12 takes into consideration heat insulation, prevention of dent of the barrel portion when holding the container by hand, prevention of deformation due to printing pressure during printing, etc. Then, it is preferable that the 0.05 to 0.5 g / cm ^3, in particular 0.1 to 0.4 g / cm ^3.

The density of the flange portion 21 of the inner layer container 2 is 0.2 considering the prevention of mouth deformation when the composite container 1 is held by hand, the flange strength when the lid is attached and peeled off, the cushioning property of the flange portion, etc. ˜1.5 g / cm ³ , particularly 0.2 to 0.8 g / cm ³ is preferable.

  The inner layer container 2 is preferably provided with a smoother inner surface than the outer surface of the trunk. The surface roughness of the inner surface of the body portion of the inner layer container 2 is the prevention of pinholes when forming a coating layer with a resin film or the like, the adhesiveness between the coating layer and the inner layer container 2 and the good appearance, etc. The thickness is preferably 3 to 15 μm, particularly 3 to 12 μm. The surface roughness of the outer surface of the body part of the inner layer container 2 increases the frictional force with the outer layer container 3 and integrates the inner layer container and the outer layer container so that they are not easily separated without using an adhesive. Taking this into consideration, the thickness is preferably 4 to 20 μm, particularly 5 to 15 μm. The surface roughness Ra is measured, for example, in accordance with JIS B0601-2001, using Surfcom [manufactured by Tokyo Seimitsu Co., Ltd.] under Gaussian correction and measurement conditions with a linear inclination correction.

  Moreover, it is preferable that the inner surface of the inner layer container 2 does not have a convex portion that becomes a trace of a steam escape slit or a trace of a suction hole provided in a dry male mold. In the case where slits and suction holes are provided in the dry-type male mold in order to prioritize the drying efficiency and the like, by providing slits and suction holes in the height direction in the dry-type male mold, those slits and suction holes are provided on the inner surface of the inner layer container 2. Even if it has the convex part used as a trace, there is little catch of the chopsticks and spoon to this convex part, there is also little catch of the contents to this convex part, and the container which is easy to eat and drink can be obtained. When a resin film is attached to the inner surface of the composite container 1 by vacuum forming to form a coating layer, the resin film is coated from the mouth of the inner layer container 2 toward the bottom. If there is a convex part that becomes a trace of a slit or a suction hole in the direction, the direction in which the film is coated coincides with the direction of the convex part, so that the resin film can be covered without hindrance, and the pin to the resin film This is preferable because holes are less likely to be generated.

  The inner layer container 2 preferably has an air permeability such that the resin film or the like can be easily sucked and deformed when a coating layer such as a resin film is formed by vacuum forming or pressure forming. The air permeability is determined according to JIS P81170-1980 using, for example, a measuring device (Tokyo Tester, Gurley's Desometer).

  The inner layer container 2 contains bulky treated pulp as a pulp component. The amount of the bulky treated pulp contained in the inner layer container 2 is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, and still more preferably 30 to 70% by weight in the pulp components constituting the inner layer container 2. When the blending amount of the bulky treated pulp in the pulp component is within such a range, the bulky effect is exhibited, and the cushioning property of the flange portion 11 and the heat insulating property of the container are improved. In addition, the amount of binder used for securing the strength of the entire container including the flange portion can be suppressed to an appropriate amount. Here, the bulky treated pulp used in the inner layer container 2 refers to a pulp fiber that has been curled or hydrophobized by a bulky treatment such as a crosslinking treatment or mercerization treatment, or the rigidity of the fiber itself has been improved. As the cross-linked pulp, commercially available curd fibers (for example, “HBA” manufactured by U.S. Warehauser), and as the mercerized pulp, commercially available mercerized pulp (for example, “POROSAUIE”, “ULTRANIER,” manufactured by Rayonnia) are used. "SULFATE").

The cross-linked pulp, mercerized pulp or bulky treated pulp can be used alone or in combination of two or more.
The mercerized pulp can be used by mixing with the crosslinked pulp at an appropriate ratio. Mercerized pulp is less bulky than crosslinked pulp, but by adjusting the mixing ratio of mercerized pulp to crosslinked pulp, the strength of the inner layer container and the moldability (transferability) of the inner surface of the inner layer container are improved. It becomes good. Moreover, flocs of pulp fibers can be suppressed, and the occurrence of papermaking unevenness can be prevented.

When the crosslinked pulp is used among the bulky treated pulp, the wet curled factor is preferably 0.1 to 1.0, particularly preferably 0.1 to 0.6. By setting the wet curled factor within such a range, desired bulkiness can be easily obtained. Further, the dispersibility in the raw material slurry is also good, the papermaking unevenness can be suppressed and uneven thickness can be prevented from occurring in the compact, and the strength and surface properties of the compact can be improved. Here, the wet curled factor, using the FQA (Fiber Quality Analyzer) was dipped in pure water at room temperature of pulp fibers, measuring the number 1000 or more, the measurement range 0.5~10mm, ((L _A / L _B ) is a value obtained by the arithmetic average of -1) and is a numerical value indicating the degree of fiber curving. Here, L _A is the actual length of the pulp fiber, and L _B is the maximum dimension of the rectangle surrounding the bent pulp fiber.

  The inner layer container 2 can contain, as the pulp component, pulp fibers that are not subjected to bulky treatment in addition to the bulky treated pulp. The pulp fiber is preferably contained in the pulp component in an amount of 10 to 90% by weight, particularly 20 to 80% by weight. When the pulp fiber is contained in such a range, the strength reduction of the flange portion and the container and the generation of paper dust can be suppressed, and the amount of binder added for obtaining strength and preventing paper dust can be suppressed. . Moreover, bulkiness is also obtained and the cushioning property of the flange portion and the heat insulating property of the container are improved. Examples of the pulp fibers include unbleached or bleached kraft pulp, sulfite pulp, alkali pulp, ground pulp, or thermomechanical pulp of softwood or hardwood. These pulp fibers can be used alone or in admixture of two or more at an appropriate ratio. In particular, by mixing two or more kinds, pulp fibers having various fiber length distributions can be prepared.

  The pulp fiber for the inner layer container preferably has a Canadian Standard Freeness (CSF) of 500 to 800 ml, particularly 600 to 750 ml. When the CSF is within this range, the drainage is good and the paper making time and drying time can be shortened. Further, papermaking unevenness can be suppressed, and uneven thickness can be prevented from being obtained in the obtained molded body, and the surface property of the molded body can be prevented from being deteriorated. Furthermore, desired heat insulation properties are easily obtained.

  The average fiber length of the pulp fibers not subjected to bulky treatment is preferably 0.4 to 5 mm, particularly preferably 0.5 to 3 mm. When the average fiber length of the pulp fibers is within such a range, moderate entanglement with the bulky treated pulp can be obtained, and the resulting molded article can be prevented from strength reduction and paper dust generation. Moreover, since flocs (aggregation of pulp fibers) do not increase and papermaking unevenness is unlikely to occur, it is possible to prevent uneven thickness from occurring and deterioration of surface properties.

  Any of the pulp fibers of wood pulp and non-wood pulp can be used for the bulky treated pulp and the pulp fiber used as the pulp component of the inner layer container 2. Further, any pulp fiber of virgin pulp and waste paper pulp can be used. These pulp fibers can be used alone or in admixture of two or more at an appropriate ratio.

The inner layer container 2 may contain 0.2 to 10% by weight of a bulking agent with respect to the pulp component. By including a bulking agent within these ranges, bulkiness can be obtained more stably.
Examples of the bulking agent include “KB115” and “KB85” manufactured by Kao Corporation, and among these, “KB115” is preferable because it can suppress bulkiness and obtain bulkiness. .

  The inner layer container 2 can contain additives such as a dispersant, a pigment, a fungicide, a sizing agent, a paper strength enhancer, a water resistance agent, and an adhesive in an appropriate ratio as necessary.

  The outer layer container 3 is a container that mainly gives strength to the composite container 1. The outer layer container 3 has a flange portion 31 that constitutes the flange portion 11.

  The thickness T31 of the flange portion 31 of the outer layer container 3 is 0.4-2 mm in consideration of prevention of mouth deformation when the container is held by hand, flange strength when the lid is attached and peeled off, thin wall, light weight, etc. In particular, 0.5 to 1.5 mm is preferable. The thickness T321 of the body portion 32 of the outer layer container 3 constituting the vicinity of the mouth portion 10 of the body portion 12 is to prevent deformation of the mouth portion when the container is held by hand, and at the mouth portion due to a compressive load in the vertical direction. Considering buckling prevention, thin wall, light weight, etc., it is preferable to set to 0.25 to 1.5 mm, particularly 0.3 to 0.9 mm. The thickness T322 of the barrel portion 32 of the outer layer container 3 constituting the central portion of the barrel portion 12 prevents deformation of the barrel portion when the container is held by hand, prevents deformation due to printing pressure during printing, and is thin and lightweight. In consideration of the above, it is preferable that the thickness is 0.2 to 1.2 mm, particularly 0.25 to 0.7 mm. The thickness T323 of the body portion 32 of the outer layer container 3 constituting the lower portion of the body portion 12 is 0.15 to 1.0 mm in consideration of buckling prevention at the bottom due to a longitudinal compressive load, thinness, lightness, etc. In particular, the thickness is preferably 0.15 to 0.6 mm. The thickness T34 of the bottom 34 of the outer container 3 constituting the bottom 14 is set to 0.1 to 1 mm, particularly 0.1 to 0.5 mm in consideration of buckling prevention at the bottom due to a longitudinal compressive load, thin wall, light weight, and the like. Is preferred. In particular, by setting the thickness of the body portion within such a range, it is easy to obtain a desired contact force by preventing deformation of the outer layer container when the inner layer container and the outer layer container are fitted.

  The elastic modulus of the body portion 32 of the outer layer container 3 including the fitting portion with the body portion 22 of the inner layer container 2 is set higher than the elastic modulus of the body portion 22 of the inner layer container 2. The elastic modulus of the trunk portion 32 is that when the inner layer container and the outer layer container are fitted, the inner layer container wall is mainly crushed and the outer layer container is not bent, ensuring the compressive strength in the vertical and horizontal directions as a container, Considering deformation prevention due to printing pressure at the time of printing, it is preferably 200 MPa to 10000 MPa, more preferably 400 MPa to 6000 MPa, and further preferably 600 MPa to 4000 MPa. Here, the elastic modulus of the body portion 32 of the outer layer container 3 is measured in the same manner as the elastic modulus of the body portion 22 of the inner layer container 2 (sample thickness is 0.37 mm). The elastic force of the outer layer container can be appropriately set by adjusting the material composition, the applied pressure during molding, and the like.

The density of the flange part 31 of the outer layer container 3 is such that the container is prevented from being deformed when the container is held by hand (gripping strength is ensured), the flange part is prevented from being deformed when the lid is attached and peeled off, thin and light. In consideration of properties and the like, it is preferably 0.5 to 2 g / cm ³ , particularly preferably 0.7 to 1.5 g / cm ³ .

The density of the body portion 32 of the outer container 3 constituting the vicinity of the mouth portion of the body portion 12 is the surface smoothness, the prevention of paper dust generation, and the deformation of the container when the container is held by hand (ensure the grip strength). Considering prevention of buckling at the mouth due to a compressive load in the vertical direction, thinness, lightness, etc., 0.5 to 2 g / cm ³ , particularly 0.7 to 1.5 g / cm ³ is preferable.
The density of the body portion 32 of the outer container 3 constituting the central portion of the body portion 12 is as follows: surface smoothness, prevention of paper dust generation, prevention of dents during conveyance, body portion when holding the container by hand with hot water In view of prevention of deformation, prevention of deformation due to printing pressure during printing, thinness, and lightness, 0.5 to 2 g / cm ³ , particularly 0.7 to 1.5 g / cm ³ is preferable.
The density of the body part 32 of the outer layer container 3 constituting the lower part of the body part 12 is in consideration of surface smoothness, prevention of dents during conveyance, prevention of deformation due to printing pressure during printing, thinness, lightness, etc. 0.5 to 2 g / cm ³ , particularly 0.7 to 1.5 g / cm ³ is preferable.
The density of the bottom 34 of the outer container 3 constituting the bottom 14 is 0.5 to 2 g / cm ³ , especially 0.7 to 1.5 g / cm in consideration of prevention of crushing of the bottom at the time of stacking and transportation, thinness, lightness, etc. ³ is preferable.

  The outer layer container 3 is preferably provided with a smooth outer surface rather than an inner surface. The surface roughness of the outer surface of the outer layer container 3 is preferably 0.5 to 3 μm, particularly preferably 1 to 2 μm in consideration of printability, prevention of paper dust generation, good appearance, and the like. The inner surface of the outer layer container 3 is preferably provided on a rough surface in order to entangle the pulp fibers of the lower density inner layer container 3 to increase the frictional resistance and enhance the integrity between the inner layer container and the outer layer container. In particular, it is preferable that the inner surface of the body portion 32 is provided on a rough surface by a mark pressed in a net shape by a net of a male mold 710 of a drying mold 700 described later. The surface roughness of the inner surface of the body portion 32 of the outer container 3 is preferably 10 to 50 μm, more preferably 12 to 30 μm. In consideration of printing, labeling, paper dust generation prevention, and the like, it is preferable that the outer surface of the outer layer container 3, particularly the outer surface of the body portion, has no trace of suction holes.

The density of the outer layer container 3 is more preferably 0.5 to 2 g / cm ³ , particularly preferably 0.7 to 1.5 g / cm ³ . When the density is within such a range, discoloration of the pulp fibers and strength reduction of the pulp fibers themselves can be prevented during dry molding, and strength and surface properties required for the outer layer container can be secured. Here, the density of the outer layer container 3 is determined from the thickness, area, and weight of the cut outer layer container. In particular, by setting the density in such a range, when the inner layer container and the outer layer container are fitted, the deformation of the outer layer container is prevented, the contact force between the inner layer container and the outer layer container is improved, and it is difficult to separate the two containers. .

  Examples of the pulp fiber for the outer layer container 3 include unbleached or bleached kraft pulp, sulfite pulp, alkali pulp, ground pulp, and thermomechanical pulp. Among these, bleached kraft pulp of conifers and hardwoods is particularly preferable from the viewpoints of moldability, whiteness, surface properties of the molded body, and strength. These fibers can be used alone or in admixture of two or more at an appropriate ratio.

  The pulp fiber for the outer layer container preferably has a CSF of 200 to 600 ml, particularly 300 to 600 ml. When the CSF is within this range, the drainage is good and the paper making time and drying time can be shortened. Further, papermaking unevenness can be suppressed, and uneven thickness can be prevented from being obtained in the obtained molded body, and the surface property of the molded body can be prevented from being deteriorated.

  In the outer layer container 3, additives such as a dispersant, a pigment, a fixing agent, a fungicide, a sizing agent, an adhesive, and a paper strength enhancer can be contained in an appropriate ratio as necessary.

In consideration of surface smoothness, the air permeability of the outer layer container 3 is preferably 30 to 120 seconds, particularly 65 to 120 seconds. The air permeability of the outer layer container 3 is measured by a method described later with the smooth surface side set to the upper side of the apparatus.
The air permeability of the outer layer container 3 is preferably larger than that of the inner layer container 2. By making the air permeability of the outer layer container 3 larger than that of the inner layer container 2, when the coating layer is brought into close contact by vacuum forming as will be described later, the outer layer container 3 becomes a ventilation resistance and becomes a mold for vacuum forming. Concentration of local suction force in the provided suction groove can be prevented, pinholes can be prevented from occurring on the resin film, and coating without unevenness of contact can be achieved.

  The inner dimension (inner diameter) of the outer portion of the outer layer container 3 is smaller than the outer dimension (outer diameter) of the inner layer container 2. The outer surface of the container is crushed and the outer dimension of the outer layer container having higher rigidity than the inner layer container is hardly deformed. For this reason, in the line conveyance on a conveyor, etc., a container flows smoothly, without a container stagnating on a conveyor. Moreover, since the outer layer container is not deformed, it is excellent in printability. Also, as will be described later, even when a coating layer such as a resin film is brought into close contact by vacuum forming, the inner layer and the outer layer are firmly integrated, so that the occurrence of inner layer cracking due to vacuum pressure is prevented. When the inner layer container is made of the same elastic modulus as the outer layer container, the heat insulation as a composite container is inferior, and it is necessary to form these containers with high dimensional accuracy in order to firmly integrate both containers by fitting. However, if the elastic modulus of the inner layer container is set lower than that of the outer layer container, it is possible to set a larger fitting margin width between the inner layer container and the outer layer container. Can be easily obtained.

  The composite container 1 having the above-described configuration has excellent heat insulation, excellent strength and surface properties of the outer layer, and is excellent in productivity because it is thin and lightweight and hardly breaks during production. is there. In particular, the inner layer container 2 and the outer layer container 3 are provided in such a manner that the outer surface of the body portion 22 of the inner layer container 2 has low density irregularities as described above, and the inner surface of the body portion 32 of the outer layer container 3 is the inner layer container 2. Since it has higher rigidity than the outer surface of the barrel 22 and has a rough, preferably mesh-like mark, the outer surface of the inner layer container 2 is crushed and the outer surface bites into the inner surface of the outer layer container 3 when both containers are fitted. It becomes a state. For this reason, the frictional force between both containers becomes high, and the inner layer container 2 and the outer layer container 3 are in an integrated state that is difficult to separate, and a container that is firmly integrated can be obtained without using an adhesive. Can do. Therefore, the production cost can be reduced and the manufacturing equipment can be simplified. In addition, since the inner layer container and the outer layer container are firmly integrated, the deformation strength of the mouth of the container is improved, the deformation and breakage of the container due to the printing pressure during printing, and the vacuum pressure during vacuum forming The effect of preventing damage to the inner layer is achieved. Further, since the inner layer container and the outer layer container are firmly integrated, the lateral compressive strength is high, and even if hot water is put in the container and held by hand, the container is easy to hold.

  Next, the composite container of the present invention will be described with reference to the drawings while referring to the manufacturing method.

  As shown in FIGS. 2 (a) to 2 (g), the composite container 1 includes an inner layer papermaking body 2 ′ and an outer layer papermaking body 3 ′, which are intermediates between the inner layer container 2 and the outer layer container 3, and a papermaking mold 200, The paper is individually made by a wet paper making method using 300 and dried with drying molds 600 and 700 to obtain the inner layer container 2 and the outer layer container 3, and then the inner layer container 2 and the outer layer container 3 are fitted together to be integrated. It is manufactured by converting.

  As shown in FIG. 2A, the papermaking portion 210 of the papermaking mold 200 has a flange portion 211 and has a predetermined taper angle and tapers toward the tip portion.

  The papermaking section 210 includes a thin-walled mold in which a porous plate is bent and welded, and a papermaking net (not shown) in which a metal net placed thereon is bent and welded. The papermaking section 310 also includes a thin-walled mold in which a porous plate is bent and welded, and a papermaking net in which a metal net placed thereon is bent and welded.

  A dry mold 600 for dry-molding the papermaking body 2 ′ includes a male mold 610 and a female mold 620 as shown in FIG. The male mold 610 and the female mold 620 are metal molds such as a rigid aluminum alloy.

  The male mold 610 has a convex shaped portion 611 corresponding to the inner surface shape of the inner layer container 2. A thin molded portion 612 having a reduced diameter corresponding to the stacking step 23 of the inner layer container 2 is provided at the tip of the molded portion 611.

  Inside the molding part 611, there are a plurality of gas-liquid flow passages 614 that are separated from the gas-liquid flow passage 613 and the gas-liquid flow passage 613 and are opened in the height direction on the outer peripheral surface, and the bottom surface in the circumferential direction. A plurality of slit-shaped airflow passages (not shown) opened in an arc shape are provided, and dewatering and exhausting are performed when the papermaking body 2 'is dried through these gas-liquid flow passages. In addition, a cartridge heater (not shown) is arranged inside the molding unit 611 so that the outer surface of the molding unit 611 can be heated.

  The female mold 620 has a concave molded portion 621 corresponding to the outer shape of the inner layer container 2. A cartridge heater 622 is disposed inside the female mold 620. Further, the female mold 620 is provided so that a predetermined clearance is formed between the convex portion of the molded part 611 and the molded part 621 when combined with the male mold 610. Although not shown in the figure, the female die 620 is provided with a slit in the circumferential direction at the body and a slit on the arc at the bottom for shortening the drying time and sucking and holding the papermaking 2 '.

The male mold 710 includes an elastic body such as a synthetic rubber such as natural rubber or silicone rubber from the viewpoint of improving durability, and a fluid-permeable stretchable papermaking net that covers the outside of the elastic body. The papermaking net has a mesh opening of 20 to 100 mesh, particularly 40 to 60 mesh, from the viewpoint of making the inner surface of the body portion 32 of the outer layer container 3 to be a rough surface as described above, particularly a mesh-like rough surface. It is preferable to use polyamide such as nylon, polyurethane, polyester, aramid, fluororesin, polyphenylene sulfide woven fabric or knitted fabric.
A plurality of gas-liquid flow passages 714 that are separated from the gas-liquid flow passage 713 and are connected to the outer peripheral surface and a plurality of gas-liquid flow passages 715 that are open at the front end surface and corners are provided inside the molding portion 711. When the papermaking body 3 ′ is dried through the gas-liquid flow passage, dehydration and exhaust are performed.

  The female die 720 has a concave shaped portion 721 corresponding to the outer shape of the outer layer container 3. A cartridge heater 722 is disposed inside the female mold 720. The female mold 720 preferably has no exhaust hole opened on the inner surface of the molding part 721 so as not to leave an exhaust hole trace on the outer surface of the inner layer container 3. For sucking and holding the body 3 ′, a slit in the circumferential direction can be provided in the body portion, and a slit on an arc can be provided in the bottom portion.

Next, a description will be given of the fitting allowance of the body portion when the two containers are virtually overlapped and the thickness α of the fitting allowance.
FIG. 3A is a partial cross-sectional view when the inner layer container 2 having the body thickness T having the flange portion 21 is accommodated in the female mold 620. FIG. 3B is a partial cross-sectional view when the outer layer container 3 having the flange portion 31 is accommodated in the female mold 720. The density of the inner layer container 2 is set lower than the density of the outer layer container 3. In order to virtually overlap the lower surface of the flange 21 portion of the inner layer container 2 and the upper surface of the flange portion 31 of the outer layer container 3, when the female mold 620 containing the inner layer container 2 is moved in the direction of the arrow, both containers are 3 (c) is entered. At this time, the body portion of the outer layer container 3 and the body portion of the inner layer container 2 are overlapped, and this overlap margin (shaded portion in FIG. 3C) is the fitting margin, and the thickness is the thickness of the fitting margin. α.
Then, when the two containers are fitted together, in order to firmly integrate the two containers without substantially deforming the outer container 3, the thickness T of the body portion of the outer container 3 and the thickness from the thickness T are obtained. It has been found that there is a preferable range for the value of the ratio (σ / T) with the difference σ (= T−α) of α. That is, when both containers are virtually overlapped as described above, 0 <(σ / T) ≦ 0.9, especially 0.1 ≦ (σ / T) ≦ 0.4, and When the maximum value of (σ / T) has a portion of 0.35 or more, it was found that the composite container 1 is a container in which both containers are firmly integrated with almost no deformation of the outer layer container 3. .

  The preferable range of the ratio (σ / T) and the above description regarding the ratio are not only when the inner layer container 2 and the outer layer container 3 both have a flange portion, but when either one of the containers has a flange portion or both containers It is also applied when there is no flange part. The (σ / T) is preferably smaller in the central portion than in the vicinity of the mouth portion in the trunk portion 12 or smaller in the vicinity of the bottom portion in the trunk portion 12 than in the vicinity of the mouth portion in the trunk portion 12. Since the mouth part is weaker than the bottom part, if the crushing amount of the inner container when the two containers are fitted is large, the mouth part is likely to be deformed, so (σ / T) is set in this way. By doing so, it is possible to obtain a strongly integrated composite container without causing deformation in the mouth. Note that the vicinity of the mouth portion in the body portion refers to a portion of 0 to 5% from the upper surface portion 110 of the flange portion 11 with respect to the height H of the composite container 1.

  The thickness T is preferably 0.1 to 1.5 mm, more preferably 0.1 to 1.0 mm in consideration of the compressive strength, grasping strength, printing strength, thinness / lightness, and moldability of the container.

  When papermaking body 2 ′ and papermaking body 3 ′ are made, as shown in FIGS. 2 (a) and 2 (d), a gas-liquid flow pipe is provided in the gas-liquid flow passage provided in papermaking sections 210 and 310. 220 and 320 are connected. And after arranging the raw material slurry injection pipes 230 and 330 so as to surround the papermaking sections 210 and 310 of the papermaking molds 200 and 300, the valves of the slurry supply pipes 231 and 331 attached to the injection pipes 230 and 330 are opened, After supplying predetermined slurry to the papermaking sections 210 and 310, the gas-liquid circulation pipes 220 and 320 are opened, and the liquid component in the raw material slurry is sucked through the gas-liquid circulation pipes 220 and 320 and the gas-liquid flow passage. The solid content in the raw material slurry is deposited on the net. When the discharge by the suction of the liquid component is completed and the papermaking bodies 2 'and 3' are formed on the surface of the papermaking net, the injection pipes 230 and 330 are retracted. Moreover, after arranging the injection pipes 230 and 330, a predetermined amount of water can be supplied, and then the slurry can be charged. Thereby, it can prevent that the pulp fiber in a slurry is entangled in the said papermaking net | network, and the mold release from the papermaking net | network can be made easy. In addition, by reducing the slurry concentration in the injection tube, it is possible to obtain a papermaking body with little papermaking unevenness without increasing the equipment such as the slurry tank, and by changing the amount of water injected, By changing the timing of opening the valves of the liquid circulation pipes 220 and 320, the amount of pulp in the height direction of the papermaking body can be changed.

  As a raw material slurry used for papermaking of the papermaking body 2 ', it is preferable to use a slurry having a pulp fiber concentration of 0.1 to 2.0 wt%. Although there is no restriction | limiting in particular in a dispersion medium, It is preferable to use water or white water as a dispersion medium from the point of handleability and production cost. Moreover, the said additive can be included in a raw material slurry in a suitable ratio as needed.

It is preferable that the raw material slurry used for papermaking of the papermaking body 2 ′ contains 0.01 to 0.5 wt% of a dispersant with respect to the pulp component. If the dispersant is 0.01 wt% or more, a dispersion effect is sufficiently obtained, and if it is 0.5 wt% or less, papermaking can be performed without requiring a long time, and contamination of the papermaking net and the mold itself can be suppressed.
Examples of the dispersant include various surfactants, polyethylene oxide or a derivative thereof, and among these, polyethylene oxide is preferable from the viewpoint of less foaming and easy handling of the slurry.

  As a raw material slurry used for papermaking of the papermaking body 3 ', it is preferable to use a slurry having a pulp fiber concentration of 0.1 to 2.0 wt%. Although there is no restriction | limiting in particular in a dispersion medium, It is preferable to use water or white water as a dispersion medium from the point of handleability and production cost. Moreover, the said additive can be contained in this slurry in a suitable ratio as needed.

Next, the papermaking bodies 2 ′ and 3 ′ are dry-molded with dry dies 600 and 700.
As shown in FIGS. 2B and 2E, the papermaking bodies 2 ′ and 3 ′ are placed in the drying dies 600 and 700 heated by the heater and press-molded while drying. The moisture content of the papermaking bodies 2 ′ and 3 ′ at this time is preferably 55 to 80%, particularly 60 to 75% from the viewpoints of shortening the drying time, smoothness of the surface, and prevention of scorching and discoloration.

  When the papermaking bodies 2 ′ and 3 ′ are dried, the liquid (vapor) of the papermaking bodies 2 ′ and 3 ′ is sucked through the gas-liquid passages of the male molds 610 and 710 and discharged to the outside.

  The mold temperature during drying of the papermaking bodies 2 'and 3' is preferably 110 to 250 ° C, particularly 120 to 230 ° C in consideration of prevention of scorching due to drying, drying efficiency, surface smoothness, and the like.

  After the papermaking bodies 2 ′ and 3 ′ are dried, the male molds 610 and 710 are retracted from the drying molds 600 and 700, and the papermaking bodies 2 ′ and 3 ′ are taken out from the male mold (see FIGS. 2C and 2F). These are integrated as an inner layer container 2 and an outer layer container 3. In addition, the water content after drying of the papermaking body 3 ′ is preferably 0 to 10% from the viewpoint of preventing the strength of the container from being lowered, preventing the deformation of the papermaking body 3 ′ at the time of fitting, and preventing separation of the fitted container. 0 to 8 are more preferable. Further, the water content of the papermaking container 2 'is preferably 0 to 15%, more preferably 0 to 10% from the same viewpoint.

  Next, as shown in FIG. 2G, the outer layer container 3 is accommodated in the fitting mold 800, and the flange portion 31 is supported from below. Then, the inner layer container 2 is inserted into the outer layer container 3 from above, and the flange portion 21 of the inner layer container 2 is pressed downward by a pressing plate (pressing means) 810 and held for a predetermined time, and these are fitted and integrated. Turn into. If necessary, trimming of the excess portion of the flange portion completes the manufacture of the composite container. The pressing force by the pressing plate is set to such a pressure that the fitting of the inner layer container and the outer layer container is completed. On the other hand, if the moving speed of the pressing plate is too large, the container will buckle, and if it is too small, the coalescence time becomes long and the productivity is lowered. The pressing force is preferably 1 to 10 MPa in terms of stress based on the container projection area in the pressing direction, and the pressing plate speed is preferably 10 mm / s to 200 mm / s.

  An adhesive may be used for joining the inner layer container 2 and the outer layer container 3 to increase the adhesive strength as necessary. As the adhesive, it is preferable to use natural adhesives such as starch and carboxymethylcellulose, and synthetic water-soluble adhesives such as polyvinyl alcohol.

  The composite container 1 of the present embodiment thus obtained is an excellent thin and lightweight container that satisfies various performances such as heat insulation, structural strength, surface properties, moldability, disposal properties, and contents preservability. In particular, it is excellent in strength against vertical compression load and resilience against deformation caused by the compression load.

  The composite container 1 may be provided with a coating layer so as to cover the inner surface and the flange portion, for example. The thickness of the coating layer is 0.02 to 0.15 mm, particularly 0.03 to 0.1 mm, considering barrier properties such as water vapor, prevention of pinholes, material costs, and prevention of tearing by scratching with a spoon or chopsticks. It is preferable to be 01 mm.

  A resin film is preferably used for the coating layer. Examples of the resin film include thermoplastic resins such as polyolefin resins such as polyethylene and polypropylene, polyester resins such as polyethylene terephthalate, polyamide resins such as nylon, polyvinyl resins such as polyvinyl chloride, and styrene resins such as polystyrene. Examples thereof include biodegradable resin films such as films, modified polyethylene terephthalate, and aliphatic polyesters. Among these, polyolefin resins are preferable in terms of production cost, moldability, and the like, and biodegradable resin films and biomass-derived resin films are preferable in terms of environment. These resin films can be used alone or in a laminate of two or more for the coating layer.

  When the coating layer is provided using a resin film, it can be formed by a conventional method such as vacuum forming or pressure forming. In the case of vacuum forming, for example, as shown in FIG. 4, a vacuum forming die 900 including a vacuum suction path 910 and a band heater 920 and a plug 930 including a heater are used. The vacuum forming mold 900 is provided with a predetermined clearance between a portion 911 facing the lower surface of the flange 11 of the composite container 1 and the flange portion 11, and a suction port for the vacuum suction path 910 is also provided in the portion 911. Keep it.

  Then, the composite container 1 is set in the vacuum mold 900, and the resin film 40 is set so as to close the opening 10 of the composite container 1. Further, the plug 930 heated from above is brought into contact with the resin film 40, the resin film 40 is pushed into the vacuum mold 900, and the inside of the composite container 1 is passed through the vacuum suction path 910 using the air permeability of the composite container 1. The resin film 40 is adhered to the inner surface of the composite container 1 by evacuation.

  At this time, the resin film 40 that has been softened by heating in advance is rolled up and brought into close contact with the lower surface of the flange portion 11 of the composite container 1. Then, unnecessary portions of the resin film 40 are trimmed to complete the formation of the coating layer 4.

The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit of the present invention.
The coating layer is preferably provided by coating the composite container with a resin film as in the above embodiment, but the coating layer can also be provided by applying a paint containing the resin component of the resin film.

  The shape of the composite container of the above embodiment has a circular cross section, but is not limited to a circular shape, and is not particularly limited to an elliptical shape, a square shape, or the like. In the above embodiment, the paper making and drying steps are used. However, the papermaking bodies 2 'and 3' may be made and then dehydrated in a dewatering type, and then dried in a drying type. Moreover, the direction of the papermaking mold, the dewatering mold, and the drying mold used in the manufacturing process can be changed as appropriate. The mold may be split or split in consideration of handling properties, mold workability, assembly performance, maintainability, and the like. Moreover, the integration method of the inner layer container 2 and the outer layer container 3 is not limited to the above, and can be appropriately changed depending on the form of the container, for example, the presence or absence of a flange.

Hereinafter, the present invention will be described more specifically with reference to examples.
By producing the composite container having the dimensions shown in Table 1 and the dimensions shown in Table 1 according to Examples 1 to 4 below, the inner layer container and the outer layer container having the elastic modulus shown in Table 2 are combined, and these are combined. Obtained. Then, the deformation amount (crush amount) of the obtained composite container with respect to the vertical compression load and the deformation amount (crush amount) when the compression load was solved were measured, and the restoration property was examined. In addition, the compressive load when buckling occurred by continuously applying a vertical compressive load was examined. In addition, in order to confirm the fitting state of the inner layer container and the outer layer container, the thickness and the separation force were measured as follows.

[Example 1]
<Production of inner layer container / outer layer container>
First, water is injected as shown in FIGS. 2 (a) and 2 (e) using a papermaking mold in which a perforated plate is bent and a metal net is welded and processed on the surface of the mold that has been welded into a male shape. Thereafter, the following raw material slurry was supplied to form a wet papermaking.
Raw material slurry for inner layer;
Pulp component formulation: (Pulp fiber (HBA (made by Warehauser) / the following outer layer pulp = weight ratio 3/7, CSF = 720 ml), pulp fiber concentration in the pulp slurry is 0.5% by weight, after water is added. Concentration is 0.25% by weight)
Sizing agent: 2% by weight of pulp
Raw material slurry for outer layer;
Pulp component blending: (pulp fiber (trade name Hinton / trade name Cenibra = 5/5 by weight, CSF = 450 ml), pulp fiber concentration in the pulp slurry is 0.5% by weight, and the concentration after adding water is 0.00. 25% by weight)
Sizing agent (2% by weight of pulp)

The obtained paper for the inner layer was placed in a dry mold as shown in FIG. 2 (b), and dry molded under the following conditions.
The temperature of the mold (620) was 200 ° C., the temperature of the mold (610) was 200 ° C., and the drying time was 25 seconds.
The obtained outer layer papermaking product was placed in a dry mold as shown in FIG. 2 (e), and dry molded under the following conditions.
Mold (720) temperature: 170 ° C
Pressing force is 9800N (pressing continues for 50 seconds)

The obtained outer layer containers are accommodated in a fitting mold, and under the following conditions, the inner layer containers are pressed by a normal temperature pressing plate as shown in FIG. A composite container 1 was obtained.
Pressing force: 1470N (Stress based on container projection area in the pressing direction: 2.1MPa)
Press holding time: 4 seconds

[Evaluation of compressive strength]
Using a universal testing machine (Orientec Co., Ltd., “Tensilon RTA500”), the resulting composite container was placed horizontally with the opening facing up, and the load cell speed was 20 mm / min. The compressive strength in the direction was measured. The compressive strength was defined as the amount of crushing at the time of loading, with the displacement when it reached 294N. Then, after maintaining the displacement for 1 hour, release the load, measure the height of the container 24 hours after releasing the load, and after releasing the difference with the height of the container before applying the compressive load The amount of crushing. Thereafter, the load cell was moved again at the same speed, and a vertical compression load was applied to the composite container to obtain a load (buckling load) until buckling. As a result, the composite container of this example had a compressive load of 637N. , Buckling occurred in the torso.

[Measurement of thickness]
The outer layer thickness was measured by a thickness meter (Nippon Parametrics Co., Ltd., Magnamic, Model 8000) using a target ball diameter of 1/8 inch. The flange thickness was measured using a caliper.

(Measurement of separation force)
Cut the flange part of the outer container of the obtained composite container, fix the flange part of the inner container with the opening of the composite container facing downward, and fix the outer container with the mouth part of the obtained composite container facing downward When the load of the load cell is measured with a universal tester (Orientec, Tensilon RTA500) with the outer surface adsorbed by a suction type at a load cell speed of 5 mm / min, the inner layer container and the outer layer container are separated. The load was the separation force. Table 3 shows the relationship between σ / T and separation force in the body of the container.

[Example 2]
The same evaluation as in Example 1 was performed except that the product manufactured in the same manner as in Example 1 was used and the longitudinal compression load was changed from 294N to 441N. In the composite container of this example, buckling occurred in the body portion at a compression load of 637N.

Example 3
Using the same inner layer and outer layer raw material slurry as in Example 1, an inner layer container and an outer layer container were prepared so as not to have the fitting allowance described above. And these containers were compounded using the dry type | mold which has a clearance corresponding to the external shape shown in Table 1, and the composite container was obtained. Evaluation similar to Example 1 was performed using the obtained composite container. When the separating force of the composite container of the present example was measured, the separating force was 39 N only due to the suction force of the outer layer container at the time of compounding, and no fitting occurred between the two containers. In the composite container of this example, buckling occurred in the body portion when the compression load was 490N.

Example 4
The same evaluation as in Example 2 was performed using a product manufactured in the same manner as in Example 3. When the separating force of the composite container of the present example was measured, the separating force was 39 N only due to the suction force of the outer layer container at the time of compounding, and no fitting occurred between the two containers. In the composite container of this example, buckling occurred in the body portion when the compression load was 490N.

(Comparative Example 1)
Using the same inner layer and outer layer raw material slurry as in Example 1, the inner layer paper body and the outer layer paper body were formed, and the dried outer layer paper body was overlaid with the wet inner layer paper body. Table 1 Using a dry type (male and female type) having a clearance corresponding to the outer shape shown in (2), both containers were combined to obtain a composite container. About the obtained composite container, evaluation similar to Example 1 was performed. When the separation force of the composite container of this comparative example was measured, the separation force was 39 N only due to the suction force of the outer layer container at the time of compounding, and no fitting occurred between the two containers. In the composite container of this example, buckling occurred at the corner of the bottom when the compressive load was 392N.

  As shown in Table 2, the composite container of each example in which the elastic modulus of the inner layer container is lower than that of the outer layer container, and the curvature radius Ro of the corner portion outside the bottom of the composite container is 5 mm or less is a vertical compressive load. It was found that the strength against deformation and the resilience against deformation caused by the compressive load are excellent.

  The use of the composite container of the present invention is not particularly limited, and the content to be contained is not particularly limited. Applications include, for example, instant cup noodles of the above embodiment, instant foods other than noodles, various foods and foods such as ice cream and confectionery, and containers for seasonings, medicines, cosmetics, detergents, and the like. In addition, a container in which an article is attached separately from the contents stored in the container main body can be mentioned.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically one Embodiment of the composite container of this invention, (a) is a half sectional view, (b) is an enlarged view of the A part of (a), (c) is B of (a) (D) is an enlarged view of a portion C in (a). It is a figure which shows typically the manufacturing process of the composite container of the embodiment, (a) is a figure which shows the papermaking process of the papermaking body for inner-layer containers, (b) is the dry molding process of the papermaking body for inner-layer containers. (C) is a view showing the inner layer container, (d) is a view showing the paper making process of the paper product for the outer layer container, (e) is a diagram showing the dry forming process of the paper product for the outer layer container, (f) ) Is a view showing a papermaking body for an outer layer container, and (g) is a view showing a state in which the inner layer container and the outer layer container are fitted. (A)-(c) is a fragmentary sectional view for demonstrating the state which overlap | superposed the inner layer container and outer layer container which were accommodated in the dry type | mold in the embodiment. It is a figure which shows typically the formation process of the coating layer in the manufacturing process of the composite container of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Composite container 10 Mouth part 11 Flange part 12 Trunk part 13 Level | step difference 14 Bottom part 2 Inner layer container 3 Outer layer container 620,720 Female type | mold (dry type)
800 fitting type 810 pressing member 900 vacuum forming die 930 plug

Claims (2)

A composite container in which an inner layer container and an outer layer container each made from a raw material containing pulp are combined,
The inner layer container and the outer layer container have a mouth part that opens upward, a trunk part that is continuous with the mouth part, and a bottom part that is continuous with the trunk part,
The inner dimension of the outer layer container body is smaller than the outer dimension of the inner container body, and when the inner container and the outer container are virtually overlapped, Have overlapping mating margins,
The inner layer container has a lower elastic modulus than the outer layer container, and a curvature radius Ro of a corner portion outside the bottom of the composite container is 5 mm or less.   The composite container according to claim 1, wherein the inner layer container contains bulky treated pulp.