JP2013256311A - Food container and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a food container capable of being molded with a smaller amount of material to contribute to resource saving and weight reduction and securing heat retaining properties of the container without crushing nonwoven fabric, and to provide a method of manufacturing the same.SOLUTION: A food container and a method of manufacturing the same are provided. The food container includes: a lamination label 2 having at least nonwoven fabric and a resin-made protective film layer disposed on front and rear both surfaces of the nonwoven fabric; and a resin-made container body 3 molded by injection molding. The lamination film 2 and the container body 3 are integrally molded by the injection molding, and a barrel part 38 of the container body 3 has a plurality of strip-like rib structures 31.

Description

  The present invention relates to a food container made of a synthetic resin having a structure for reducing weight or a heat insulating structure, and a method for manufacturing the same.

  When a food container that stores high-temperature contents does not have a heat insulating structure, the temperature of the contents is conducted to the outer surface and the outer surface becomes hot. Such containers are hot and difficult to hold with bare hands and can cause burns. Also, the contents of the container often need to be kept as long as possible.

  For this reason, various containers with heat insulation means are known. For example, in JP-A-7-291250 (Patent Document 1), heat insulation in which a fiber sheet or a nonwoven fabric is bonded to the outer surface of a container as a heat insulating material, or a side wall of a container has a double wall structure with a gap inside. A container is disclosed. In addition, in the market, a heat insulating container is generally used in which a laminated label obtained by adhering a heat shrinkable synthetic resin film such as PET (polyethylene terephthalate) to one or both surfaces of a nonwoven fabric is closely attached to the outer surface of the container. Some are printed.

  Among this type of conventional heat insulating container using a non-woven fabric, the one with the non-woven fabric exposed is molded resin enters the gap through the non-woven fabric layer when in-mold molding is performed together with the container body, and the heat insulation is not exhibited. In addition, since the non-woven fabric bonding surface is not flat, as described above, the conventional laminated label that directly bonds the plastic film to the non-woven fabric with the adhesive has a problem that the non-woven fabric and the plastic film have insufficient bonding strength and are easily peeled off. was there.

  Above all, a conventional heat insulating container has a large contact surface when it is held in the hand because the heat insulating label surface outside the container is uniformly flat. For this reason, the heat insulating effect is only the thickness of the nonwoven fabric, and a sufficient heat insulating effect was not obtained.

Furthermore, the heat-insulated container formed by in-mold molding with the printed plastic film bonded to the nonwoven fabric as the heat insulating material for the container shrinks the nonwoven fabric with the cooling of the container body, resulting in fine wrinkles in the printed film, The sharpness of printing was not always sufficient.
In addition, because the printed pitch is not accurate, the molded product obtained by laminating a non-stretched plastic film with printing on the nonwoven fabric maintains the precision of the gravure printing by keeping the positional accuracy of the label and the printing design constant. It was difficult to do.

  In view of the above problems, the applicant disclosed in Japanese Patent Application Laid-Open No. 2007-153359 (Patent Document 2), an insulated container in which a container body and a laminated label having a nonwoven fabric are integrally molded to ensure heat insulation, and its manufacture. A method and a laminated label for this method were proposed.

However, when the above-mentioned heat insulating container is molded in-mold with the laminated label, depending on the molding conditions, the nonwoven fabric in the laminated label is crushed by the pressure at the time of molding, and there is a problem that heat insulation is not obtained so much. Further, when the pressure at the time of molding is reduced or the thickness of the container main body is reduced, it becomes difficult to spread the molding material throughout the mold, and it is difficult to mold the container main body itself.
JP 7-291250 A JP 2007-153359 A

  An object of the present invention is to provide a food container that can be molded with a small amount of material. Or it is providing the food container which has a heat insulation effect and a clear printed display is hold | maintained also in injection molding.

  Another object of the present invention is to provide a method for producing a food container that can be molded with a small amount of material. Moreover, it is providing the manufacturing method of the food container which has the said heat insulation.

In order to achieve the above object, the food container of the present invention has the following constitution.
(1) a laminated label having at least a nonwoven fabric and a protective film layer made of resin disposed on both surfaces of the nonwoven fabric;
It has a resin container body molded by injection molding,
The laminated film and the container body are integrally formed by the injection molding,
And the food container which has a some strip | belt-shaped rib structure in the trunk | drum of a container main body.
(2) The food container according to (1), further comprising a resin-made printed film layer on which the laminated film is printed.
(3) The food container according to (1) or (2), wherein a thickness between the rib structures is substantially equal to a thickness of the laminated label, and the laminated label serves as a part of the container body.
(4) The thickness between the rib structures is thicker than the thickness of the laminated label, and the recesses are formed between the rib structures of the container main body by the same material as the rib structure (1) or (2) Food containers.
(5) The food container according to any one of (1) to (4), wherein the laminated film is embossed.
(6) A laminated label having at least a nonwoven fabric and resin protective film layers disposed on both front and back surfaces of the nonwoven fabric is disposed in a mold of a container body at the time of injection molding,
The mold has a recess that forms a flow path of the raw material resin at a site that forms the container body,
Injection molding by injecting raw material resin between the laminated label and the mold core,
A method for producing a food container, wherein the laminated film and the container body are integrally molded to obtain a food container.
(7) The method for producing a food container according to (6) above, wherein the body portion of the container body has a belt-like rib structure formed by a recess serving as the flow path.
(8) A food container having a plurality of strip-shaped rib structures that serve as a flow path for a resin material at the time of molding on the body of a resin-made container body molded by injection molding.

  The food container and its manufacturing method of the present invention can be formed with a small amount of material by devising the shape of the container body, that is, the shape of the mold used at the time of molding, and contribute to resource saving and weight reduction. There is an advantage that the amount of garbage can be reduced.

  Further, the food container of the present invention and the manufacturing method thereof use a rib structure or a container body having a thick part and a thin part. In this case, the nonwoven fabric is not crushed, and it is possible to ensure the heat retaining property of the container. Moreover, in addition to the heat insulation of the nonwoven fabric layer of the laminated label, the embossed surface is formed on the outer surface of the container, so the contact surface when held by hand is small, local, and also injected into the laminated label. Since a void is formed by shrinkage after molding, the heat insulating effect is remarkably improved, and a heat insulating container that is gentle to the hand and excellent in heat retaining action can be obtained.

  Further, since the film layer is interposed between the container body and the nonwoven fabric layer, the molten resin does not enter during container injection molding. Since in-mold labeling is performed at the same time as the injection molding of the container, the labeling process is omitted, and the in-mold labeling of the laminated label can be performed also on the side surface of the container body having a concavo-convex shape. Therefore, since the non-woven fabric has good followability to the shape of the container, it is difficult to become wrinkles and peeling does not occur.

  Since the printed plastic film layers are laminated in a bonded state, a laminated label having excellent printing pitch accuracy and beautiful gravure printing can be obtained.

The front view which is a half-section of the food container of the present invention Plan view of the food container of the present invention Bottom view of the food container of the present invention A-A 'sectional view of FIG. B-B 'sectional view of FIG. The expanded sectional view of the lamination label which uses the food container of the present invention The expanded sectional view of the other lamination label used for the food container of the present invention Manufacturing process diagram of nonwoven fabric Embossing roll enlarged cross-sectional view Schematic enlarged cross-sectional view of the nonwoven fabric Manufacturing process diagram of laminated label Manufacturing process diagram of laminated label Food container injection molding process diagram Partial enlarged cross-sectional view of the container side wall after food container injection molding

  The food container of the present invention has a laminated label having at least a nonwoven fabric and a resin protective film layer disposed on both front and back surfaces of the nonwoven fabric, and a resin container body molded by injection molding, The film and the container body are integrally formed by the injection molding, and the body portion of the container body has a plurality of strip-like rib structures. The laminated film may have a printed film layer for imparting design properties to the container.

  Thus, heat insulation can be provided to a container main body by shape | molding integrally the laminated | multilayer film which has a nonwoven fabric, and a container main body. In addition, since the container body has a plurality of strip-shaped rib structures, this rib functions as a flow path for the resin material at the time of molding, enabling molding with a small amount of resin material, and the pressure at the time of molding to the rib portion. By limiting, it can prevent that a nonwoven fabric is crushed with the pressure at the time of shaping | molding, and a heat insulation function is impaired.

  Hereinafter, the food container and the manufacturing method thereof according to the present invention will be described with reference to the drawings. For example, as shown in FIGS. 1 to 5, the food container 1 of the present invention is formed by integrally injection-molding the molten synthetic resin of the container body 3 with the laminated label 2 facing outward. Here, FIG. 1 is a front view having a half section showing the appearance of a food container, FIG. 2 is a plan view, FIG. 3 is a bottom view, FIG. 4 is a cross-sectional view taken along line AA ′ of FIG. It is BB 'sectional drawing of.

  In the figure, the food packaging container is disposed in close contact with the outer periphery of the body 38 of the container body 3 so that the laminated label 2 is integrated. The detailed configuration of the laminated label 2 will be described later. In the configuration of the illustrated example, the container body 3 has a general cup shape having a cylindrical body portion that is open at the top and closed at the bottom. Further, the trunk portion 38 has alternately the thick portions 31 and the thin portions 32 formed in a band shape from the upper portion to the lower portion of the container body 3. As will be described later, the thin portion 32 can be replaced with the laminated label 2 on the outer periphery. Further, the container main body can be formed integrally with the laminated label, and various shapes can be selected without being limited to the shape of the illustrated example as long as it has a rib structure.

  The thick part 31 functions as a flow path of the resin material for molding at the time of molding. Moreover, the thin part 32 functions as an area | region which has the heat insulation function by the nonwoven fabric mentioned later. For this reason, the thick portion 31 and the thin portion 32 are preferably configured so that those formed in a line shape or a strip shape from the container opening portion to the bottom portion are alternately arranged as in the illustrated example. By alternately arranging in this way, the material can be efficiently supplied from the thick part to the thin part at the time of molding, and the material can be distributed throughout the container body even with a smaller amount of material. And when carrying out in-mold shaping | molding with the lamination | stacking label which has a nonwoven fabric, in a thin part, a nonwoven fabric is not crushed and heat insulation can be ensured.

  As described above, the container body can be made into a food container having a heat insulation function by being in-molded together with the laminated label, but can also be used as a food container without providing the laminated label. In this case, since the container body can be formed with a small amount of material, a thin and lightweight container can be provided. The shape of the container body is not particularly limited, and the upper part as shown in the illustrated example opens, and even in a cup shape having a cylindrical body part and a bottom part, a bowl shape, a cup shape, or an upper part is opened. A square box may be used.

  The rib structure by the thick part 31 and the thin part 32 in the container main body 3 is normally formed in the container body, and is not formed in the bottom of the container or the collar around the opening. Further, a plurality of rib structures are usually formed in a band shape having a constant width extending from the container opening to the bottom. The rib structure may be branched or bent halfway as long as it does not hinder molding. Further, when in-mold molding is performed with a laminated label, it is important that the laminated label is formed in a region where the laminated label is disposed. In addition, you may form a rib structure other than a container trunk | drum as needed.

  Further, the upper portion of the container body near the opening may be formed of only the container body material without forming a rib structure, and the strength near the opening may be ensured. In this case, the region without the rib structure is preferably 1/12 or more and 1/4 or less of the height of the body portion. Further, the thickness of this portion may be changed to ensure the strength. If the area without the rib structure is small, it is difficult to ensure the strength of the opening, and if it is too large, the heat insulating effect is lowered. Moreover, it can replace with the area | region which does not have a rib structure, can devise the magnitude | size and shape of a collar, or can add another structure and can ensure intensity | strength.

  The number and size of the thin part (concave part) and the thick part (convex part) in the rib structure are not particularly limited, and may be adjusted to the optimum number and size according to the size and thickness of the container. In the case of a general cup-shaped container, the diameter is 50 to 100 mm, and the number of thick portions (convex portions) is preferably 20 to 48, more preferably 30 to 42. In addition, the width of the normal convex portion is narrow. The width of the protrusion relative to the width between the specific recesses or ribs is preferably about 1/8 to 1/3, more preferably about 1/6 to 1/4. The thickness of the convex portion with respect to the concave portion when forming the concave portion is preferably 1.3 to 6 times, more preferably about 1.5 to 4.0 times.

  Moreover, in this invention, it is also possible to comprise the area | region between the convex parts used as a rib structure only with a lamination | stacking label, without forming a recessed part in a container main body. In this case, the container main body formed of the molding resin is substantially composed of the periphery of the opening, the convex portion, and the bottom portion. And only a lamination label exists between the said convex parts.

  The thickness of the concave portion in the rib structure is determined by the thickness of the portion corresponding to the concave portion of the mold and the thickness of the laminated label. That is, the thickness of the portion corresponding to the concave portion of the mold needs to be substantially the same as the thickness of the laminated label or slightly thicker by the thickness corresponding to the thickness of the concave portion of the container body to be formed. When the thickness of the portion corresponding to the concave portion of the mold is slightly thicker than the thickness of the laminated label, the raw material resin can enter the concave region between the convex portions to form the concave portion. In addition, when the thickness of the laminated label is equal to the thickness of the concave portion, the raw material resin cannot enter the concave region between the convex portions, and only the laminated label exists in the region between the convex portions. Even such a structure can be used without any problem as long as the performance required for a food container such as hermeticity can be secured. On the other hand, when the thickness of the portion corresponding to the concave portion of the mold becomes thicker than the thickness of the laminated label, a phenomenon that the nonwoven fabric is crushed by the raw material resin also appears in a region other than the convex portion, so that the heat insulating performance is lowered.

  By adopting the rib structure of the present invention, it becomes possible to form with the same size and with the amount of raw material that has been difficult to form in the past. Specifically, the molding can be performed at 90% or less, particularly 77% or less of the amount of the conventional raw material. Moreover, the weight can be further reduced by providing the function of the concave portion of the laminated label as described above. Specifically, the molding can be performed at 80% or less, particularly 65% or less of the amount of the conventional raw material.

  The laminated label used for the container body of the present invention is not particularly restricted, but a laminated body having the following constitution is preferred. 6 and 7 are cross-sectional views showing a preferred configuration of the laminated label, and show an enlarged cross-section before in-mold forming used for the container 1.

  6 and 7, the laminated label 2 uses a nonwoven fabric original fabric 7 which is a laminated body in which protective film layers 5 and 6 are laminated on both the front and back surfaces of the nonwoven fabric 4 by heat fusion. In addition, an uneven surface is formed by forming a large number of embosses on either the front or back surface of the laminate. Furthermore, a printing film layer 9 having a printing layer 8 provided on the inner surface side on one side (uneven surface in the embodiment of FIG. 6 and flat surface in the embodiment of FIG. And laminated to form a laminate film.

  Examples of the nonwoven fabric 4 include those manufactured by a spunbond method, a melt blow method, a dry method, a wet method, and the like according to the classification based on the fleece formation method. Among these, a spunbond nonwoven fabric formed by the spunbond method is preferable. . The spunbond nonwoven fabric is formed by melting a thermoplastic polymer and discharging it into a continuous long fiber. Specific materials for the nonwoven fabric include polypropylene, polyethylene, polyesters such as polyethylene terephthalate, nylon, polylactic acid, etc. Among them, polypropylene, polyethylene, especially composites with other materials are easy, and heat sealing From the viewpoint of good adhesive strength such as polyethylene, polyethylene is preferred.

As the thickness of the non-woven fabric 4, if it is too thin, the heat insulation effect is low, and if it is too thick, there is a problem in the container production process, so it is preferably about 0.06 to 1.0 mm, more preferably about 0.08 to 0.75 mm. Yes, the basis weight is 10 to 200 g / m ^2, more preferably about 50 to 150 g / m ² .

  As the material of the protective film layers 5 and 6 laminated on both the front and back surfaces of the nonwoven fabric 4 by heat fusion, a resin film material used for a general laminate film can be used. Specific examples include polypropylene, low density polyethylene, ionomer, ethylene vinyl acetate copolymer, polyethylene terephthalate, etc. Among these, polypropylene film is preferable, and unstretched polypropylene film is particularly preferable. The thickness is preferably about 20 to 30 μm.

  The protective film layers 5 and 6 are disposed on the inner side of the nonwoven fabric 4 on the container side. If the nonwoven fabric 4 is exposed, the molten resin in the container body enters the nonwoven fabric 4 layer during in-mold injection molding. This is because the heat insulating property is hindered. The reason why the layers are laminated by heat fusion is to improve the lamination strength with the printing film layer 9 and prevent peeling.

  As the printing film layer 9 laminated on either the front or back surface of the nonwoven fabric raw fabric 7, a resin film material used for a general laminate film can be used. Specific examples include polypropylene, low density polyethylene, ionomer, ethylene vinyl acetate copolymer, polyethylene terephthalate, etc. Among these, polypropylene is preferable, and a biaxially stretched polypropylene film excellent in pitch accuracy is particularly preferable. The thickness of the film is preferably about 20 to 30 μm.

  The reason why the biaxially oriented polypropylene film is used for the printing film layer is that it is possible to produce a beautiful label having excellent design characteristics without deteriorating printing such as beautiful gravure printing. When an unstretched polypropylene film is used, the printing pitch accuracy is poor, and the position of the printing design with respect to the label does not fall within a predetermined range, so that the aesthetic quality of the label is lowered.

  On the inner side surface of such a printing film layer, a design to be displayed in advance is printed. This printed plastic film layer is laminated on one of the plastic film layers 5 and 6 of the nonwoven fabric original fabric 7 with an adhesive layer 10 in between, with the printed surface inside. At this time, as shown in FIG. 6, the printed plastic film layer 9 may be laminated on this surface with the concave-convex plastic film layer 5 of the nonwoven fabric raw fabric 7 outside, and conversely, FIG. As shown in FIG. 3, the printed plastic film layer 9 may be laminated with the flat side plastic film layer 6 of the nonwoven fabric original fabric 7 facing outside.

  In the illustrated example, the case where the adhesive is applied as the laminating means is illustrated, but the present invention is not limited to this. For example, a melt synthetic resin extrusion laminating means may be used.

  Next, the manufacturing method of the laminated label 2 is demonstrated along a figure. 8-13 is the schematic which showed an example of the manufacturing process of the said laminated label 2 with which it uses for the in-mold injection molding of the food container 1 of this invention.

  First, as shown in FIG. 8, the sheet of nonwoven fabric 4 supplied from the nonwoven fabric feeder 12 is overlaid on the upper surface of the unstretched plastic film layer 6 drawn from the first feeding roll 11. Next, the unstretched plastic film layer 5 fed from the second feed roll 13 is overlaid on the upper surface of the sheet of the nonwoven fabric 4. In this way, a three-layer sheet in which the front and back surfaces of the sheet of the nonwoven fabric 4 are sandwiched with the non-stretched plastic film layers 6 and 5 can be obtained. And the flat roll 14 and the embossing roll 15 which mutually press-contact in the conveyance process of the said 3 layer sheet | seat are provided, and the heat-fusion lamination | stacking by thermocompression bonding is performed by passing between these rolls.

  At this time, as shown in FIG. 9, the embossing roll 15 has a large number of irregularities or protrusions 15a formed on the outer peripheral surface thereof, and the outer peripheral surface of the flat roll 14 is formed smoothly. The embossing roll 15 and the flat roll 14 are both heated to the fusing temperature of the plastic film layers 5 and 6. Therefore, when the laminated film passes between the embossing roll 15 and the flat roll 14, unstretched plastic film layers 5 and 6 are thermocompression bonded to the front and back of the nonwoven fabric 4 as shown in FIG. In addition, one surface is formed as an uneven surface by the embossing roll 15 and the other surface is formed flat. Finally, the laminated film processed into the nonwoven fabric 7 is taken up by the winder 16.

  In the next step, as shown in FIG. 11, a biaxially stretched plastic film layer 9 having an inner surface printed thereon is wound and disposed on the feeding machine 17. The printed plastic film layer 9 is fed out from the feeding machine 17 and passed through the adhesive coating machine 18 to apply the adhesive to the printing surface. Thereafter, the adhesive is dried through the dryer 19 and drawn out. The dryer is configured using a dryer or the like.

  On the other hand, the nonwoven fabric unwinding machine 20 is provided with the nonwoven fabric sheet 7 wound around the winder 16 in the previous step. Then, when the printed plastic film layer 9 subjected to the adhesive coating process is conveyed, the nonwoven fabric original fabric 7 is fed out from the nonwoven fabric original fabric feeder 20, and the printed plastic film layers 9 are stacked. At this time, it is necessary to overlap the nonwoven fabric raw fabric 7 so that the printed layer 8 of the printed plastic film layer, that is, the adhesive layer 10 is on the inner side. Then, the laminated sheet 22 having a laminated structure as shown in FIGS. 6 and 7 is generated by being pressed by passing between the pair of adhesive rollers 21 and adhesively laminated (dry laminated). The obtained laminated sheet 22 is taken up by a winder 23.

  Next, the in-mold forming process of the container body and the laminated film will be described. First, as shown in FIG. 12, the laminated sheet 22 is punched into a shape corresponding to a side development view of a desired container and processed into the laminated label 2. After that, the punched laminated label 2 is rounded so that both end edges are close to each other and formed into the cylindrical body 24. At this time, the both side edges of the laminated label 2 are usually rounded so as to be close to each other. However, the two side edges may be fixed in advance by welding, bonding, or the like, if necessary. What is necessary is just to adjust the arrangement | positioning state of the both-ends edge of the lamination | stacking label 2 by how a finished design and shape are made.

  Next, as shown in FIG. 13, the cylindrical body 24 obtained by rounding the laminated label 2 is disposed inside the cavity 26 of the mold 25. Grooves corresponding to the rib structure (convex portion) 31 shown in FIG. 1 are formed in the mold 25, and ribs are formed in the container main body by the grooves and function as a flow path for the resin material. . In addition, when the both ends of the laminated label 2 are made close to each other without banding to form the cylindrical body 24, both ends of the laminated label are preferably arranged at positions corresponding to the rib portions. Next, the mold 26 is combined with the cavity 26 of the mold 25 and the core 27.

  Next, when a molten raw material resin for a container body, for example, a polypropylene resin, is injected into the mold 25 in the injection molding process, the gap between the cylinder 24 of the laminated label 2 disposed in the cavity 26 and the mold core 27. Is filled with a raw material resin. At this time, the laminated label 2 is heat-sealed to the outer surface of the container body 3 by heat during molding, and is laminated and molded integrally with the container body. Finally, when the molded product is taken out from the mold 25, the food container 1 having the structure shown in FIG. 1 is obtained.

  The container body 3 of the obtained food container 1 shrinks and becomes smaller by cooling after injection molding as shown in FIG. At this time, for example, in the case of the laminated configuration of FIG. 6, the heat-sealed plastic film layer 6 of the nonwoven fabric original fabric 7 heat-sealed to the container body 3 follows the container body 3 and contracts. However, the non-woven fabric 4 on the outside is formed by overlapping thin fibers and has a lot of space in the cross section, and is not firmly bonded to the plastic film layer 6 and therefore does not shrink. For this reason, the layer of the nonwoven fabric 4 serves as a buffer wall and extends from the nonwoven fabric 4 to the outermost inner surface printed plastic film layer 9, that is, not only the nonwoven fabric 4 layer, but also the heat-sealed plastic film layer 5, the adhesive layer 10, and the printing layer. 8 and the printed plastic film layer 9 do not follow the shrinkage of the container body 3 and do not shrink.

  By the way, the 4 layers of nonwoven fabric are originally an aggregate of fine fibers and have many spaces inside. For this reason, even if the container main body 3 contracts, a large unevenness change does not occur to such an extent that the coarse fiber density becomes somewhat dense. However, each outer layer is a resin film, and when the container body 3 and the plastic film layer 6 contract, the material cannot be absorbed by the contraction and deforms to form a clear uneven embossed surface 28.

  Furthermore, the upper surface of the plastic film layer 5 outside the non-woven fabric 4 layer, that is, the interface with the adhesive layer 10 is not a strict flat surface, and the opposing surfaces of the plastic film layer 5 and the adhesive layer 10 are completely It is not glued to. For this reason, a plurality of local voids 201 are formed between the plastic film layer 5 and the adhesive layer 10 due to the shrinkage after the injection molding.

  Further, the four layers of the nonwoven fabric and the plastic film layers 5 and 6 on the emboss forming side are heat-sealed only at the concave portions of the emboss formed on the plastic film layers 5 and 6. For this reason, the shrinkage | contraction of the container main body 3 after injection molding produces the some local space | gap 202 also between the nonwoven fabric 4 layers and the plastic film layers 5 and 6 by the side of embossing. The cross-section of the four layers of the nonwoven fabric is originally a porous shape having a space 41 between the fibers 40, but in combination with the local space 202, a more effective heat insulating effect is exhibited.

  A gas barrier such as oxygen is laminated on the container by laminating a film in which an inorganic oxide such as aluminum oxide or SiOx is deposited between the plastic film layers 5 and 6 and the printing film layer 9 on at least one side of the raw nonwoven fabric 7. Sexuality may be imparted.

  In the illustrated example, the case where the printing layer 8 is applied to the inner side surface of the biaxially oriented polypropylene film layer 9 is exemplified, but conversely, the printing layer 8 may be applied to the outer side surface of the film layer 9. Moreover, although the case where the printed film layer 9 was laminated | stacked on the film layer 5 or 6 of the nonwoven fabric raw fabric 7 using the adhesive agent was illustrated, you may laminate | stack not only this but by another joining means.

Next, an Example is shown and this invention is demonstrated in detail.
A food container having a cup-like structure as shown in FIGS. The container body 3 has a general cup shape having a cylindrical body portion 38 having an opening at the top and a bottom portion being closed in the configuration of the illustrated example. A flange-shaped collar 34 is formed around the opening 39 so that a lid can be fused and bonded after the food is stored. The bottom portion is constituted by a thread take-up 35 and a bottom surface 36 covering the entire bottom, following a normal cup. In addition, the container main body of a present Example was made into the diameter of 76 mm including a collar, and about 114 mm in height, and the convex part of the rib structure was arrange | positioned equally in the circumferential shape, and 36 pieces were formed.

  As shown in FIG. 2, the non-stretched plastic film layers 5 and 6 were laminated on both the front and back surfaces of the nonwoven fabric 4 by heat-sealing. At this time, a large number of embosses were formed on the surface to form a concavo-convex surface, which was used as the base material of the laminated nonwoven fabric original fabric 7. A printed plastic film layer 9 was adhered and laminated on the uneven surface side of the nonwoven fabric original fabric 7 via an adhesive layer 10 to obtain a laminated sheet.

For the nonwoven fabric 4, a polypropylene spunbond nonwoven fabric having a basis weight of about 50 g / m ² and a thickness of 0.3 mm was used. For the plastic film layers 5 and 6, unstretched polypropylene film of about 20 to 30 μm was used. As the printed plastic film layer 9, a biaxially stretched polypropylene film having a thickness of about 20 to 30 [mu] m and having an inner surface subjected to printing such as gravure printing was used.

  The manufacturing process of the lamination sheet was performed according to the procedure shown in the said FIGS. The conditions and the like in each step at this time are the same as those generally known in the production of this type of laminated sheet for labels, and details thereof are omitted here.

  Next, as shown in FIG. 12, the laminated sheet 22 was punched into a shape corresponding to a developed side view of the cup-shaped container and processed into a laminated label 2. Thereafter, the punched laminated label 2 was rounded so as to be close to both edges, and formed into a cylindrical body 24.

  Next, as shown in FIG. 13, the cylindrical body 24 obtained by rolling the laminated label 2 was disposed inside the cavity 26 of the mold 25. Grooves corresponding to the rib structure shown in FIG. 1 are formed in the mold 25 to form ribs and function as a flow path for the resin material. The rib structure is formed in a region reaching the bottom except for the upper part 33 of the container body part 38. The upper portion 33 of the container body, that is, the vicinity of the opening, is formed entirely of a resin having a thickness of a convex portion in order to maintain strength. Next, the cavity 26 of the mold 25 and the core 27 are combined to form a molding mold 25, and a molten polypropylene resin, which is a raw material resin for the container body, is injected, and the cylindrical body 24 and the mold core 27 of the laminated label 2 are injected. The raw material resin is filled in between. Although the laminated label 2 is disposed on the outer surface side of the container body 3, it is heat-fused by the heat at this time and integrally laminated. Finally, the molded product was taken out from the mold 25 to obtain the food container 1 having the shape shown in FIG.

  In addition, a food container with a laminated label produced using a conventional mold for producing a container having no rib structure in the above-mentioned container was also prepared as a comparative sample.

  The obtained container with a laminated label of the present invention has a convex portion 31 forming a rib structure and a concave portion 32 formed by a thin resin layer therebetween except for the upper portion 33 near the opening in the trunk portion 38 of the container body 3. The structure which had was formed. Further, the upper portion 33 had a resin corresponding to the thickness of the convex portion over the entire circumference to maintain the strength of the opening. The convex portion 31 is formed with a step portion 31a in the vicinity of the bottom of the container that is caught when the containers are stacked and stored. Further, the laminated label 2 was heat-sealed to the container body 3 and formed integrally with the container body 3. And it turned out that the nonwoven fabric 4 and an embossed structure remain without being crushed especially in the area | region of the recessed part 32 without a rib, and can fully exhibit the heat insulation effect. Even in the convex part of the rib structure, it was found that the non-woven fabric 4 and the region where the embossed structure was not crushed remained to some extent, and this part also contributed to the heat insulation.

  On the other hand, the comparative sample using the container of the conventional structure is that the nonwoven fabric 4 and the embossed structure appear on the surface under normal production conditions, but the nonwoven fabric is crushed by the pressure at the time of molding, and the inside There was almost no space left. For this reason, it turned out that heat insulation is inadequate.

  As shown in FIG. 3, the laminated sheet in Example 1 is formed by using a laminated nonwoven fabric raw material 7 in which a large number of embosses are formed on the back surface of the nonwoven fabric 4 to form an uneven surface, and the flat surface of the nonwoven fabric raw material 7. Further, the printed plastic film layer 9 is bonded and laminated through an adhesive layer 10. A food packaging container was prepared in the same manner as in Example 1 except that the flat plastic film layer 6 of the raw nonwoven fabric 7 was placed outside and the printed plastic film layer 9 was laminated with the adhesive layer 10. As a result, it was found that food packaging containers substantially the same as in Example 1 can be obtained in both appearance and heat insulating performance.

In Example 1, a food container was prepared in the same manner as in Example 1 except that a polypropylene spunbond nonwoven fabric having a basis weight of about 100 g / m ² and a thickness of 0.6 mm was used.

  As a result, the convex portion of the container body was formed in the same manner as in Example 1, but the concave portion could not be formed because the raw material resin could not enter the region between the convex portions. However, it has been found that the laminated label present in this portion functions as a part of the container body and can be used without any problem as a food container although it is inferior to the sample of Example 1 in strength. Further, it was found that the heat insulation is slightly better than Example 1.

  A conventional mold for molding only a container body without a rib structure having a size substantially the same as in Example 1 was prepared, and the weight of the raw material resin was calculated to be 14.3 g. In order to reduce the weight as much as possible with the same size, a container mold having the same rib structure as in Example 1 was designed and manufactured. Moreover, when the weight of the raw material used was calculated, it became 11g.

  When the obtained mold was molded without using a laminated label, it was found that molding was possible with 11 g of raw material. It was also found that in the conventional shape without a rib structure, when the amount of raw material is 11 g, it is difficult to form the container into a normal shape without the raw material resin reaching the entire mold. From this, it was found that with a mold having a rib structure, the material can easily flow even with a small amount of resin material that is difficult to mold with the conventional shape, can be molded normally, and the weight of the container can be reduced.

  Since the heat insulation property of the container is remarkably improved, the present invention is widely used as a container requiring heat insulation, such as a container for pouring hot food, beverages, an instant food for heating the contents in a range, a container for retort processed food, etc. Can be used. Moreover, it can be widely used for food packaging containers that require a clear printed surface.

  Moreover, since a container main body can be shape | molded with few materials, it can be widely used as a food packaging container which needs weight reduction and resource saving.

DESCRIPTION OF SYMBOLS 1 ... Thermal insulation container 2 ... Laminated label 3 ... Container main body 4 ... Nonwoven fabric 5, 6 ... Protective film layer 7 ... Laminated nonwoven fabric 8 ... Printed layer 9 ··· Print film layer 10 ··· Adhesive layer 11 and 13 ··· Feed roll 12 ··· Nonwoven fabric feed device 14 ··· Flat roll 15 · Embossing roll 16 · · · Winder 17 ··・ Feeding machine 18 ... Adhesive coating machine 19 ... Dryer 20 ... Non-woven fabric web feeding machine 21 ... Adhesive roller 22 ... Laminated sheet 23 ... Winding machine 24 ... Laminated label cylinder 25 ... mold 26 ... cavity 27 ... core 28 ... uneven embossed surfaces 41, 201, 202 ... gap

Claims (8)

A laminated label having at least a nonwoven fabric and a protective film layer made of resin disposed on both front and back surfaces of the nonwoven fabric;
It has a resin container body molded by injection molding,
The laminated film and the container body are integrally formed by the injection molding,
And the food container which has a some strip | belt-shaped rib structure in the trunk | drum of a container main body.   Furthermore, the food container of Claim 1 which has the resin-made printing film layer which gave printing to the said laminated | multilayer film.   The food container according to claim 1 or 2, wherein a thickness between the rib structures is substantially equal to a thickness of the laminated label, and the laminated label serves as a part of the container body.   The food container according to claim 1 or 2, wherein a thickness between the rib structures is thicker than a thickness of the laminated label, and a recess is formed between the rib structures of the container main body using the same material as the rib structure.   The food container according to claim 1, wherein the laminated film is embossed. A laminated label having at least a nonwoven fabric and resin protective film layers disposed on both front and back surfaces of the nonwoven fabric is disposed in a mold of the container body at the time of injection molding,
The mold has a recess that forms a flow path of the raw material resin at a site that forms the container body,
Injection molding by injecting raw material resin between the laminated label and the mold core,
A method for producing a food container, wherein the laminated film and the container body are integrally molded to obtain a food container.   The manufacturing method of the food container of Claim 6 which has a strip | belt-shaped rib structure formed in the trunk | drum of the said container main body by the recessed part used as the said flow path. A food container having a plurality of strip-shaped rib structures that serve as a flow path of a resin material at the time of molding on a body portion of a resin-made container body molded by injection molding.

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