JP4557295B2 - Food storage container - Google Patents

Description

The present invention relates to a food container that can be wrapped to cover a container opening formed from a pulp material. Specifically, meat, fish, a lever, etc. are stored, and the container opening is wrapped by a film. The present invention relates to a food storage container that does not deform even when covered.

Conventionally, plastic materials such as polyurethane foam have been used as food storage containers such as trays for storing food. However, since plastic materials are not easily post-processed after use, there is a strong demand for food storage containers made of vegetable fiber materials from the viewpoint of environmental protection.

A container made of pulp cardboard is manufactured by forming incisions at the four corners, standing up the side pieces, pasting the ends of the side pieces together at the corners, and gluing them together by hand. However, there was a drawback that the cost was extremely high. For this reason, it is hardly spread as a food storage container such as an inexpensive tray sold in a supermarket or the like.

Further, a paper container in which a large number of ridges are formed in a bellows shape at a corner portion and a film is coated on the surface has been known. However, since the bellows easily opens, there is a problem that strength is weak.

In order to solve such a problem, the present applicant has a step of forming a cardboard material from a pulp material (pulp or a vegetable fiber material containing pulp as a main component), and a heat seal ability on the back surface of the cardboard material. A step of coating a thermoplastic resin having, a step of forming cut portions for forming side pieces at the four corners of the cardboard, and the cardboard obtained in this way is heated and pressed with a pair of concave and convex press dies. Then, a food container having side piece overlapping portions at the four corners was developed, and a patent application was filed first (Patent Document 1).

Further, the present applicant has a step of forming a cardboard material of a predetermined size from a pulp material, a step of coating a thermoplastic resin having a heat sealing ability on the back surface of the cardboard material, and four corners of the cardboard material. A step of forming a folded piece connecting side pieces adjacent to each other, and a food storage container in which the cardboard obtained in this way is heated and pressed with a pair of concave and convex press molds, and the folded pieces are superposed on the side pieces. Was developed and a patent application was filed earlier (Patent Document 2).

However, when the upper end of the container is folded back to form a bowl-shaped portion, a lot of wrinkles may be generated or torn, and a beautiful bowl-shaped portion cannot be formed.
In addition, since all of the above containers are made of pulp material, the strength is weak. Therefore, there is a problem that the containers are deformed when they are wrapped with an automatic machine and the opening is covered with a film. Even if a bowl-shaped portion having a semicircular cross section is provided at the upper end of the container, the deformation of the container cannot be avoided.

JP 2006-315687 A JP2007-1621

This invention is made | formed in view of such a point, and the invention of Claim 1 aims at providing the food storage container which can form the beautiful bowl-shaped part with commercial value.
In addition to the above object, the invention according to claim 3 is a food storage that is difficult to deform even when the opening of a food storage container formed from a cardboard made of pulp material is covered with an automatic machine. The purpose is to provide a container.

In order to achieve the above object, the present inventor, as a result of earnest research, formed a folded piece shorter than the adjacent portions connecting adjacent side pieces, and the folded pieces overlapped with the adjacent side pieces and contained food. When the upper end of the container is folded outward to form a bowl-shaped part, the bowl-shaped part formed by folding the upper part of the short V-shaped folded piece has no wrinkles and can be formed beautifully. And reached the present invention.
Furthermore, the fact that the hook-shaped portion is formed in a semi-polygonal cross section makes it difficult to deform even if the opening is covered with a film by wrapping with an automatic machine, and the present invention according to claim 3 has been reached. . Further hardly deformed when the inner surface of the food container laminating a thermoplastic resin film.

That is, the present invention according to claim 1 comprises a cardboard formed from a pulp material, and a folded piece shorter than adjacent portions connecting adjacent side pieces formed at the four corners of the cardboard, The folded piece is overlapped with adjacent side pieces and folded back at the upper end of the food container to form a bowl-shaped portion, and is folded back at a portion above the short folded piece. .
The back surface of the cardboard material is coated with a thermoplastic resin having a heat sealing ability, and the folded piece overlaps the adjacent side piece, and the adjacent one side piece back surface and the other side piece surface adhere to each other. Thus, only the back surface can be coated to form a food container (claim 2) .
It is preferable to coat the back surface with a thermoplastic resin because the food storage container can be easily formed and the outer surface is waterproof / oilproof and can be removed even if it is colored.

When the bowl-shaped portion is formed in a semi-polygonal shape with an open bottom surface, a food container can be obtained that is hardly deformed even when wrapped by an automatic machine and covered.
The folded piece is preferably formed in a V shape (Claim 4), and the tip of the V-shaped folded piece preferably reaches the bottom of the container to be formed (Claim 5).
The hook-shaped portion is preferable because it can be easily formed in a U-shaped cross section (Claim 6 ). Note that the U-shape includes a shape tapered or expanded toward the opening.

It becomes difficult to deform | transform by sticking the thermoplastic resin film which carried out the heat lamination to the inner surface of the said food container (Claim 7 ). In addition, the cardboard is preferably set to a thickness of 230 g to 320 g / m ² for cost reasons (Claim 8).

As the pulp material, in addition to a single pulp, a mixture of pulp and a vegetable fiber material other than pulp (such as straw, sugar cane or kenaf) can also be used. In addition, you may use used paper, such as a newspaper, as a material of a pulp.

According to the present invention, a folded piece shorter than an adjacent portion connecting adjacent side pieces is formed, and the folded piece is overlapped with the adjacent one side piece so that the upper end portion of the food container is folded outward. When forming the hook-shaped portion, the portion above the short folded piece is folded back so that a beautiful hook-shaped portion without wrinkles can be formed.
Further, by forming the cross-sectional semi-polygonal shape of the collar-like portion lower surface is open, even over the top surface by wrapping an opening of a container made of a pulp material automatic machine with film, since the container is unlikely to deform, Since the tray can be formed from a pulp material that has not been used conventionally as a tray or the like, it has a tremendous effect of facilitating disposal compared to a plastic tray.

The cause of the effect of the present invention is that the double portion is folded by folding the portion above the short V-shaped folded piece, so that a beautiful bowl-shaped portion can be formed.
Further, thought the flange portion more to a shape having corners, such as a U-shaped section, holding the wrapping film in both flanged portion corners and flanged tip hardly obtained Rukara deformed ing. When the thermoplastic resin film is laminated, the deformation of the container is effectively prevented.

Next, an embodiment of the present invention will be described.

In order to manufacture the container of the present invention, first, a food container is formed from a pulp material (pulp or a material containing pulp as a main component).
In order to form a food container from a pulp material, a cardboard material having a predetermined size is formed from a pulp material, a thermoplastic resin having a heat sealing ability is applied to the back surface, and side pieces are formed at the four corners of the cardboard material. What is necessary is just to heat-press the cardboard-like material in which the cutting part which forms is formed with a pair of uneven press dies. In order to press with a press die, the opposing side piece must be raised first.

FIG. 1 shows an example of a mold used for this purpose, and rods 2 and 2 ′ are fixed to one opposing portion of the periphery of the mold recess 1. The side piece to be raised first may be placed on the rods 2 and 2 '.

In order to produce a cardboard from a pulp material, a known method may be used. That is, what suspended the pulp material in water should just make a cardboard thing through a plowing process, a chopping process, and a drying process. The cardboard material obtained in this way is cut into the developed shape of the container or lid to be formed. In addition, it is good for a cardboard to contain a water-proofing agent. In addition, pulp from old paper such as old newspaper can be used instead of virgin pulp.

As the vegetable fiber material to be used with the pulp in the present invention, straw, sugar cane or kenaf can be used, but the virgin pulp alone or the pulp from waste paper alone is used from the viewpoint of strength and hygiene. The latter is preferable from the viewpoint of price.

The step of coating the thermoplastic resin having the heat sealing ability may be before or after being cut into a developed shape. The thermoplastic resin is preferably coated on the back side of the cardboard. The reason why the thermoplastic resin is coated is that it can be easily formed in a container with a mold, and infiltration of moisture, blood, juice, etc. can be prevented. As the thermoplastic resin, it is particularly preferable to use polyethylene or polypropylene.

The content of the thermoplastic resin varies depending on the type of the thermoplastic resin, but preferably the content is 3% to 6%. If it is less than this, the coating effect will not be sufficiently obtained, and if it is too much, black smoke will be emitted during incineration and clog the furnace filter. Here, the “content” is a percentage of the “mass of the applied heat sealant” with respect to the total mass of the cardboard material on which the thermoplastic resin is applied on one side.

The cardboard-like material formed in this way is formed with folded pieces connecting the side pieces at the four corners. The tip of the folded piece is made to reach the bottom surface of the container to be formed. The folded piece is preferably formed in a V shape with an angle of 20 to 60 °.

Then, a crease is formed at the boundary between the bottom surface and the side surface. The crease is preferably formed by a punching die.

In order to form a food container with a pair of concave and convex heating press molds, a cardboard-like object is placed on the concave mold shown in FIG. 5, and one opposing side piece is more than the other opposing side piece. First, the container is formed by pressing and pressing with a convex mold from above, and at the same time, the four corners are heat-sealed, and the food storage container 4 having the U-shaped cross-section 3 shown in FIG. It can be manufactured in a process. The hook-shaped part 3 is formed in a U-shaped cross section because, as shown in FIG. 1, a ring-shaped ridge 5 having a square cross section is provided on the outer periphery of the concave upper end of the concave mold.

A bent portion (flange) 6 in the outer horizontal direction is continuously provided at the lower end of the bowl-shaped portion 3 having a U-shaped cross section. Thus, by providing the bending part 6, the part which protruded from the container of the laminated thermoplastic resin film can be cut | disconnected easily. The thermoplastic resin film protruding from the container is cut together with the bent portion 6.

FIG. 3 shows another embodiment of the food container used in the present invention, which has folding pieces 8 for connecting side pieces 7a and 7b (7b and 7c) adjacent to the four corners. 8 is formed shorter than both adjacent side portions, and the thermoplastic resin is coated only on the back surface. This is pressed and heated with the mold shown in FIG. 1 to form a container, and at the same time, the four corners are heat-sealed, and a food container 4 ′ having a bowl-shaped portion 3 ′ having a U-shaped cross section shown in FIG. It can be manufactured in a process.

When the side walls 7a and 7c are erected first in FIG. 3, the short V-shaped folded piece 8 is also erected together. As shown in FIG. 4, the short V-shaped folded piece 8 is separated from the side wall 7b as shown by the arrow. Adhere to the surface. The surface of the portion longer than the short V-shaped folded piece 8 of the side wall 7b is simultaneously stuck to the back surface of the side wall 7a.

When the side wall 7b is erected first in FIG. 3, the short V-shaped folded piece 8 is also raised together. As shown in FIGS. 5 and 6, the short V-shaped folded piece 8 is formed on the surface of the side walls 7a and 7c. Overlapping. The surface of the part longer than the short V-shaped folding piece 8 of the side walls 7a and 7c is simultaneously adhered to the back surface of the side wall 7b.

In the above embodiment, since the portion above the short V-shaped folding piece 8 is folded by pressing with the concave and convex mold, the bowl-shaped portion 3 ′ having a U-shaped cross section can be easily formed as shown in FIG. Can be formed. If the V-shaped folded piece 8 is lengthened and folded together with the V-shaped folded piece 8, a lot of wrinkles may be generated or torn, and a beautiful bowl-shaped portion 3 'cannot be formed.

As described above, as shown in FIG. 6, the cardboard-shaped bowl-shaped cross-section formed by the cardboard-like cut surface 9 positioned above the folded piece at the corner and the container upper end folded back outwardly. A container having parts 3 and 3 'is obtained. As shown in FIG. 7, when the folded piece has a shape in which a short folded piece 8 and a long folded piece 8 ′ are connected in series, the short folded piece 8 has a long back surface attached to the back surface of the long folded piece 8 ′. The portion above the short folded piece 8 on the back surface of the folded piece 8 'is adhered to the side wall 7b. If the length of the long folded piece 8 'is shorter than the side wall 7c, this container can be a container in which the cut surface of the cardboard is located at the upper end.

If the container obtained in this way is thicker than 320 g / m ² as virgin pulp, it can be made difficult to deform even if it is wrapped with an automatic machine. Become. In addition, since the cut surface 9 of cardboard is located on the inner surface or upper end of the container, if the meat, fish, etc. are accommodated and slanted or inverted, blood or juice will permeate from the cut surface 9 and the container There are drawbacks that make it dirty.

When a thermoplastic resin film is laminated on this container, it can be made a container that is difficult to be deformed in the lapping process even if it is thinned to 230 g to 320 g / m ² . In addition, it is possible to completely prevent blood or liquid juice from infiltrating from the cutting portion 9. As the thermoplastic resin film, polyethylene, polypropylene, biodegradable resin film, or the like can be used.

Lamination of the thermoplastic resin film can be performed as follows.
(1) As shown in FIG. 8 , air suction holes or air suction perforations 10 are formed in the food container.
(2) The container having the air suction holes or the air suction perforations 10 formed in this manner is fitted into the mold having the number of fitting holes (for example, 5 to 10 pieces). . A hot plate is disposed directly above the mold at intervals.
(3) Next, the thermoplastic resin film is pulled out between the food container and the hot plate.
(4) Then, the thermoplastic resin film is lowered and placed on the food storage container. In this state, the thermoplastic resin film sags slightly downward. When the inside of the mold is depressurized and air is sucked and removed from the air suction hole or the air suction perforation 10 of the food container, the thermoplastic resin film adheres to the food container and is heated by the lowered hot plate and laminated. To do. The hot plate rises to its original position.
(5) Slide the mold and cut the rear end of the film. For example, 5 to 10 laminated food containers are taken out from the mold. The mold is returned to its original position. The connected containers are cut into individual products with a film cutting machine. In the above embodiment, the outer horizontal bent portion 6 is continuously provided at the lower ends of the hook-like portions 3 and 3 ′, so that the laminated film can be easily cut together with the bent portion 6. .

If a container in which a large number of ridges (uneven strips) are formed in the vicinity of the overlapping portion 11 of the side piece at the four corners, an air outflow path is formed by this ridge and the thermoplastic resin film. There is no need to drill holes. The ridges, ridges, or concavo-convex portions are not particularly limited as long as an air outflow path reaching the upper end from the bottom surface is formed. The ridges are preferably formed at the four corners because the thermoplastic resin film can be easily adhered uniformly. In particular, it is preferably formed in the vicinity of the overlapping portion 11 of the side piece and the folding piece 8 of FIG.

Since the food storage container may be placed on a cutting board to store sashimi and the like, it is preferable to coat the outer peripheral surface with a synthetic resin in advance so that moisture, blood and the like do not enter. For this purpose, if the concave portion that is recessed upward is formed on the bottom surface, and the air suction hole or the perforation for air suction is formed on the upper end of the concave portion (the bottom surface of the concave space), the water, blood, etc. on the cutting board are air. The suction hole can be prevented from touching. It is preferable to form four or more air suction holes or air suction perforations formed on the bottom surface at predetermined intervals so that the degree of pressure reduction is the same between the container and the thermoplastic resin film. Although the height of the concave portion depends on the size of the concave portion, the height of water accumulation is usually lower than 2 mm, so it is preferably about 2 to 4 mm.

Further, even if the recess is not provided, an air suction hole or a perforation may be formed on the outer peripheral surface at a position of 2 mm or more, preferably 4 mm or more from the bottom surface. Also in this case, it is preferable to provide four or more at the outer periphery (preferably four corners) facing each other at a predetermined interval.

The food container produced by the method of the present invention is a food container that is wrapped with a film like a tray.

It is a perspective view which shows an example of the metal mold | die which manufactures the food storage container used for this invention. It is a perspective view which shows an example of the food storage container of this invention. It is a partial expanded view which shows an example of the food container of this invention. It is a partial perspective view which shows the manufacturing method of the food storage container of this invention. It is a partial perspective view which shows the manufacturing method of the food storage container of this invention. It is a partial perspective view which shows the other example of the food storage container of this invention. It is a partially expanded view which shows the other example of the food container of this invention. It is a partially expanded view which shows the example which laminates the thermoplastic resin film on the food container of this invention.

1 ··········································· 2 ... Ring-shaped ridge 6 ..... Folded parts 7a, 7b, 7c, 7d ..... Side piece 8 ..... V-shaped insert piece 9 ...・ Cut surface 10 ・ ・ ・ ・ ・ ・ Air suction hole or perforation 11 for air suction

Claims (8)

A cardboard formed from a pulp material, and a folded piece shorter than an adjacent portion connecting adjacent side pieces formed at the four corners of the cardboard, the folded piece overlapping the adjacent side piece. When the upper end portion of the food container is folded outward to form a bowl-shaped portion, the container opening is covered by wrapping, characterized in that it is formed by folding a portion above the short folded piece. Food container. The back surface of the cardboard material is coated with a thermoplastic resin having a heat sealing ability, and the folded piece overlaps the adjacent side piece, and the adjacent one side piece back surface and the other side piece surface adhere to each other. The food container according to claim 1 . The food container according to claim 1 or 2, wherein the bowl-shaped part is formed in a semi-polygonal shape with a lower surface opened. The food container according to any one of claims 1 to 3, wherein the folded piece is formed in a V shape. The food container according to claim 4, wherein the tip of the V-shaped folded piece reaches the bottom of the container to be formed. The food container according to claim 1, wherein the bowl-shaped portion is formed in a U-shaped cross section. The food container according to any one of claims 1 to 6, further comprising a heat-laminated thermoplastic resin film on an inner surface of the food container. The cardboard-like material, Food container according to claim 1, the thickness of the 230g~320g / ^{m 2.}

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