JP4816204B2 - Paper container - Google Patents

Description

  The present invention relates to a paper container for storing foods such as pudding and yogurt.

Conventionally, a cup-shaped paper container consisting of a trunk and a bottom has been widely used as a container for containing this type of food, and the periphery is sealed by a flange located at the upper edge of the trunk after containing the food. It is sold in the form of products covered with a lid. In a paper container used for such a product, the paperboard used as the trunk and bottom is made by stacking synthetic resin on both sides of a paper base as shown in Patent Document 1, for example, and the container is manufactured. It is possible to properly paste the body of the body and to join the body and the bottom, and to ensure proper water resistance and protect food.
In addition, some paper containers are in the form of cans. In this case, as shown in Patent Document 2 and Patent Document 3, an embossed portion is formed on the body portion in order to differentiate the texture and feel from metal cans. There is something that provided.
JP 2003-285817 A JP 2003-205928 A JP 2001-063720 A

By the way, in the above cup-shaped paper container, the outer surface of the trunk of the paper container has conventionally exhibited a flat curved surface without unevenness, but it gives a new appearance when displaying products at a store, As a means for responding to this requirement, the body is embossed in the same way as the can-shaped paper container. It was considered to provide a part.
In the cup-shaped paper container, the shape of the inner surface of the barrel is uneven to prevent food from remaining on the inner surface of the barrel when scooping out the stored food such as yogurt with a spoon. It is desired to maintain a flat surface that is not flat. Therefore, as shown in the above-mentioned Patent Document 2, it has been studied to provide an embossed part in which only the outer surface side of the body part is uneven.

  In the embossing so as not to affect the inner surface side, small convex portions and small concave portions are regularly arranged alternately on the outer surface side of the body portion. However, since the paper base material in the plate material of the trunk part has a certain degree of hardness, the surface shape of the paper base material itself is not deformed according to the designed uneven shape of the embossed part. I can't expect it. Therefore, in order to make it easy to reproduce the uneven shape with the resin layer on the outer surface side, it is necessary to prepare a paperboard whose thickness of the resin layer on the outer surface side is conspicuous. However, such a special paperboard is not used as a board material for a cup-shaped paper container, raising the material cost.

In addition, as described above, the embossed portion that does not affect the inner surface side is composed of small convex portions and small concave portions. However, since these small convex portions and small concave portions are arranged alternately and regularly, there is no pattern.
However, when composing the appearance of the product container, the design is generally determined first, and the general consumer can first visually confirm the resin layer on the outer surface side of the trunk. The pattern is determined first. That is, an image pattern associating with the stored food, or a pattern that provides good sensitivity when visually observed is determined. For example, it is a fine irregular mosaic pattern or vein pattern, but in such an embossing in which small convex portions and small concave portions are alternately arranged regularly, as described above, the embossing itself is Because it was unpatterned, it could not be expressed at all.

  In view of the above circumstances, an object of the present invention is to make it possible to form a designed pattern on a resin layer on the outer surface side of a body portion by embossing such as a relief mold. The purpose is to improve.

The present invention has been made in consideration of the above problems, and in a cup-shaped paper container having a trunk and a bottom made of paperboard in which synthetic resin is laminated on both sides of a paper base, the outer surface side of the trunk The resin layer is provided with a pattern composed of fine grooves formed by embossing the resin layer when in a soft state , and the pattern corresponds to a pattern printing portion on a part of the outer periphery of the paper substrate. The paper container characterized by being in the position to be provided is provided to solve the above-mentioned problems.
In the present invention, it is preferable that the resin layer on the outer surface side of the body board has at least one layer of an olefin resin such as polyethylene resin and polypropylene resin.
Further, in the present invention, the paper base material is preferably a paper material having a majority of long fibers, a basis weight of 150 to 350 g / m ² and a density of 0.8 to 1.0.
Moreover, in this invention, the thickness of the resin layer which consists of said olefin resin can be 15-40 micrometers, Preferably it can be set as 20-30 micrometers.
In the present invention, it is preferable that the soft state of the resin layer on the outer surface side of the body portion is formed by applying heat at or above the resin softening point.
Further, in the present invention, the fine concave portion of the resin layer on the outer surface side of the body portion is formed by removing a member of the body portion whose inner surface side is received by a receiving body whose peripheral surface has a flat curved surface without unevenness. It is good that it is formed by embossing from the surface side.

According to the first aspect of the present invention, since the pattern is formed of fine grooves formed by embossing the resin layer on the outer surface side of the body portion in the soft state, fine lines expressed by the fine grooves are provided. The pattern that emphasizes can be obtained, and the intended pattern can be expressed by the resin layer.
According to invention of Claim 2, formation of a fine groove becomes more favorable.
According to the invention of claim 3, since the long fibers occupy the majority in the paper base material, taking advantage of the high strength by having the long fibers, the rupture is maintained while maintaining the recessed shape at the embossed portion. Since the concave shape is easily maintained in the paper base material itself, the concave groove shape by the stamping on the resin layer on the outer surface side is expressed in an appropriate state. Since the reaction force does not increase, fine resin breakage at the embossed portion of the resin layer, that is, pinholes do not occur.
According to the invention of claim 4, the moldability of the shape of the fine groove formed by embossing, that is, the formation of the pattern is improved.
According to the invention of claim 5, the movement accompanied by the spread of the resin in the resin layer at the time of embossing becomes good, and the moldability of the shape of the fine groove, that is, the pattern formation becomes good. .
According to the invention of claim 6, the resin layer on the inner surface side of the body portion is maintained in a flat curved surface shape, and the occurrence of pinholes in the resin layer on the inner surface side can be prevented.

Next, the present invention will be described in detail based on the embodiment shown in FIGS.
In the figure, reference numeral 1 denotes a cup-shaped paper container. The paper container 1 includes a body 2 formed by bending a paperboard 4 into a cone shape and bonding edges together, and a folded portion around the lower end of the body 2. The bottom part 3 is formed by sandwiching the periphery of the paperboard 4 and thermocompression bonding to connect the paperboard as a bottom plate. The periphery of the upper end of the body part 2 is formed as a flange projecting outward. The outer periphery of the lid material (not shown) is sealed in the portion by a method such as heat sealing, and the upper surface as a container is covered with the lid material.
The paperboard 4 that is a packaging material for the body portion 2 and the bottom portion 3 of the paper container 1 is the same material, and this paperboard 4 is a laminated component mainly composed of paper. The layer structure is shown in FIG. 2, and the paperboard 4 is obtained by laminating a resin layer 6 having at least one layer made of an olefin resin such as polyethylene and polypropylene on both surfaces of a paper substrate 5.

And in the said trunk | drum 2, pattern printing (not shown) is given to a part of outer periphery of the paper base material 5, and a fine pattern is formed on the resin layer 6 on the outer surface side at a position corresponding to the pattern printing portion. 7 is provided. The pattern 7 is embossed with a mold such as a relief mold designed so that a set pattern can be expressed when the resin layer 6 on the outer surface side of the body 2 is in a soft state. It is comprised from the fine groove 8 obtained by doing in this way.
The fine concave grooves 8 are formed by embossing so that a large number of fine concave grooves 8 are continuous. Therefore, the pattern 7 is expressed in a state that is easy to visually recognize as thin lines formed by many fine grooves 8 are continuous, and for example, it can be easily visually confirmed that it is a mosaic pattern. ing. Also, the finger touch is formed so as to be obtained as a touch different from the touch on the flat curved surface of the portion where the pattern 7 is not formed.

As described above, the pattern 7 on the body 2 is formed from the fine grooves 8 formed by embossing the resin layer 6 on the outer surface side of the body 2 when the resin layer 6 is in a softened state. It can be obtained as follows. For example, in the form of the packaging material before cutting out the paperboard 4 of the trunk portion 2, the paper base 5 has a thickness of 300 μm, and the inner and outer surfaces of the resin layer 6 are made of a polyethylene resin having a thickness of 30 μm. The outer surface side is a single resin layer made of a polyethylene resin having a thickness of 20 μm.
Then, as shown in FIG. 3, in the preheating step in which the packaging material 9 is passed through the heat roll 10, heat is applied at or above the softening point of the resin constituting the resin layer 6 to form a softened state. It passes through the pushing device 11. Of course, the heating temperature is a temperature at which the packaging material 9 can be transferred without damaging the resin layer 6.

In the pattern embossing device 11, a rubber cylinder 12 having a curved surface with a flat peripheral surface as a receiving cylinder and a plate cylinder 13 as an impression cylinder provided with a relief printing mold bent on the peripheral surface are opposed to each other. Therefore, the plate cylinder 13 is arranged so as to correspond to the resin layer side that forms the pattern 7 in the packaging material 9, and the plate cylinder 13 is synchronized with the arrival of the pattern formation position in the packaging material 9. It is provided so as to be embossed at the pattern forming position. Since the portion that receives the resin layer on the inner surface side of the body portion 2 is the rubber body 12 having a flat curved surface as described above, the flat form of the resin layer on the inner surface side is not impaired. Thus, pinholes are reliably prevented from occurring at positions corresponding to the portions of the plate cylinder to be embossed. The plate cylinder 13 is cooled, and the resin layer is embossed with a set pattern while cooling the softened resin layer (resin layer on the outer surface side). The resin layer is better reproduced and does not lose its shape.
Thereafter, a paperboard for obtaining the body part 2 is obtained from the embossed packaging material 9, and a cup-shaped paper container is manufactured by an existing cup molding machine using the paperboard of the bottom part 3 as well.

In the above embodiment, the resin layer 6 on the outer surface side of the body portion 2 is made of polyethylene resin and the thickness is 20 μm, and the resin layer 6 on the inner surface side is made of polyethylene resin and has a thickness of 30 μm. When the resin layer 6 on the outer surface side is a single layer made of an olefin resin, a thickness in the range of 15 to 40 μm is favorable, and a more preferable thickness range is 20 to 30 μm.
Moreover, about a paper base material, as mentioned above, a long fiber shall occupy the majority (the paperboard which contains many fibers obtained from the chip material in the softwood called N material), and a basic weight of 150-350 g / m < ² >. And a density of 0.8 to 1.0 is good.
It is desirable that the temperature of the resin on the embossing side that has reached the pattern embossing device after the preheating step for obtaining a soft state before embossing is a temperature between the softening point and the melting point (flow start point) ( (Polystyrene resin has no melting point and becomes the starting point of flow).

  Next, confirmation of the quality of pattern formation using the above-described embossing method for three packaging materials a, b, and c provided with a resin layer of a polyethylene resin layer on both sides of a paper base, and a paper base as a comparison The quality of pattern formation was confirmed using the above-described embossing technique in the two packaging material examples d and e in which the basis weight was outside the above range and the technique using the embossing plates. The results are shown in Table 1.

From Table 1, it can be judged that a paper base material having a basis weight of 300 g / m ² and 350 g / m ² and a resin layer thickness of 20 μm and 30 μm on the outer surface of the body is good.

In the above embodiment, the front and back resin layers of the paperboard have been described as a single layer of olefin resin. If the olefin-based resin layer is present on the outermost layer and the paper substrate side, it is good in edge bonding with the paperboard of the trunk, and bonding between the bottom and the trunk, and This is because it is advantageous for pattern formation on the outer surface side, but the present invention is not limited to this, and it is sufficient that there is at least one layer of olefin resin. For example, the configuration of the paperboard 4 of the trunk 2 is
(Outer side of container) Polyethylene terephthalate resin layer 12 μm / Polyethylene resin layer 20 μm / Paper substrate 300 μm / Polyethylene resin layer 20 μm / Polyethylene terephthalate resin layer PET 12 μm / Polyethylene resin layer PE 20 μm (Inner side of container)
It is also possible to incorporate layers having various barrier functions in the front and back resin layer 6.

It is explanatory drawing which shows an example of the paper container which concerns on this invention. It is explanatory drawing which expands and shows the pattern part in an example roughly. It is explanatory drawing which shows embossing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Paper container 2 ... Body part 3 ... Bottom part 4 ... Paperboard 5 ... Paper base material 6 ... Resin layer 7 ... Pattern 8 ... Fine groove 9 ... Packaging material 10 ... Heat roll 11 ... Pattern embossing device 12 ... Rubber cylinder 13 ... plate cylinder

Claims (6)

In a cup-shaped paper container provided with a body part and a bottom part made of paperboard in which a synthetic resin is laminated on both sides of a paper base material, the resin layer in a soft state is formed on the resin layer on the outer surface side of the body part. A paper container provided with a pattern composed of fine concave grooves formed by embossing , wherein the pattern is located at a position corresponding to a pattern printing portion on a part of the outer periphery of the paper base .   2. The paper container according to claim 1, wherein the resin layer on the outer surface side of the body board has at least one layer of an olefin resin such as polyethylene resin or polypropylene resin. The paper substrate, a paper container according to claim 1 or 2 basis weight long fibers account for more than half is paper material density 0.8-1.0 at 150 to 350 g / ^{m 2.}   The paper container according to any one of claims 1 to 3, wherein a thickness of the resin layer made of the olefin-based resin is 15 to 40 µm, preferably 20 to 30 µm.   The paper container according to any one of claims 1 to 4, wherein the soft state of the resin layer on the outer surface side of the body portion is formed by applying heat equal to or higher than a resin softening point.   The concave portion of the resin layer on the outer surface side of the body portion is formed by embossing from the outer surface side a member of the body portion whose inner surface side is received by a receiving surface having a flat curved surface with no unevenness. The paper container according to any one of claims 1 to 5, wherein the paper container is formed.

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