JP3075141B2 - Insulated cup - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulated cup having a protective cover attached to a cup body, and more particularly to an insulated cup for so-called instant foods and beverages in which hot water is poured into the contents for eating.

[0002]

2. Description of the Related Art As a cup for drinking coffee or the like, a paper cup having an inner surface coated with a polyethylene film is used. 2. Description of the Related Art There is known a technique for matting a surface of a polyethylene film in order to improve slippage with a mold during cup molding and release of a product from a cup in a vending machine.
The ten-point average roughness of the polyethylene film by the mat processing is set to about 5 μm.

[0003] On the other hand, there is a known one in which the periphery of a paper cup body is covered with a paper protective cover having a heat insulating structure. The cup configured in this way has the advantage that disposal at the time of disposal is easy and the material can be reused if necessary. One example of the protective cover has a layer structure of embossed paper and liner paper adhered to the side wall of the cup body.

[0004]

However, the heat insulating cup in which the cup body is covered by the protective cover, however, has a high coupling force when the cups are nested one another due to the elasticity of the protective cover. For example, this type of insulated cup is transported and stored in a nested stack prior to filling the contents. Therefore, when trying to feed cups one by one by the automatic feeding device from this state,
The problem of cup separation occurs. According to experiments by the present inventors, it has been found that even if a resin film on the inner surface of the cup body is subjected to a matting process of about 5 μm, good cup separation cannot be obtained. The present invention has been made in view of the above-described conventional problems, and has as its object to provide an insulated cup with good cup separation.

[0005]

The heat-insulating cup according to the present invention comprises a cup body having a paper side wall and a paper bottom wall;
And a protective cover made of paper, which covers the side wall and is attached to the side wall, wherein an inner surface of the side wall is covered with a resin film having a thickness of 20 μm to 60 μm,
The surface of the resin film is matted, and the ten-point average roughness is 10 μm to 30 μm and the thickness of the resin film is 6 μm.
0% or less. In a preferred embodiment, the outer surface of the protective cover is covered with a varnish layer and is smooth.

[0006]

In the present invention, when cups are nested one on another, the inner surface of the matted cup comes into contact with the outer surface of the protective cover of another cup. The coefficient of static friction between the inner surface and the outer surface is reduced by matting the inner surface of the cup, so that the cup is separated well regardless of the high elasticity of the protective cover. Further, the ten-point average roughness of the resin film surface is set to 60% or less of the thickness of the resin film, thereby preventing the occurrence of pinholes. In particular, when the outer surface of the protective cover is covered with the varnish layer and is smooth, the cup separation is further improved.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a partially cutaway perspective view showing the heat insulating cup and the lid according to the embodiment of the present invention separated from each other, and FIG. 2 is a partially cutaway front view of the heat insulating cup shown in FIG.

The cup body 12 has a paper-made side wall 14 formed as a truncated cone-shaped cylinder, and a bottom wall 16 that closes the small diameter end of the side wall 14. The side wall 14 is formed by rolling a single piece of paperboard into a truncated cone shape, and overlapping and adhering both side ends 15. The bottom wall 16 has a shallow cylindrical shape and has legs, and is fitted into an end of the frustoconical side wall 14. Side wall 1
The small-diameter end of 4, ie, the periphery of the lower end, is folded inward so as to enclose the leg of the bottom wall 16, thereby ensuring the sealing performance.

The large-diameter end of the side wall 14, that is, the periphery of the open end is bent outward to form a flange portion 18. The flange portion 18 is used to reinforce the cup body 12 and to attach the sheet-like lid 11. The lid 11 is made of paper,
The lower surface is coated with a heat insulating coating. The lid 11 is attached after the contents are filled in the cup body 12. Instead of the sheet-like lid 11, a cap (not shown) made of a transparent resin molded body or the like can be attached to the flange portion 18. An annular embossed line 19 is also formed on the side wall 14 so as to project outward. Embossed wire 19
When the liquid is injected into the cup body 12, it functions as a mark as a measure of the injection amount.

A protective cover 20 is disposed so as to cover substantially the entire periphery of the side surface of the cup body 12, ie, the outer surface of the side wall 14. The protective cover 20 includes an embossed paper 24 adhered so as to cover the entire outer surface of the side wall 14 and an adhered liner paper 28 adhered so as to cover the entire embossed paper 24.
To form a multilayer structure.

The paperboard forming the side wall 14 and the bottom wall 16 of the cup body 12 is made of white high-quality paper, having a basis weight of about 210 g / m ² and a thickness of about 280 μm. Side wall 14
And a thickness of about 45 μm on the inner surface of the paperboard constituting the bottom wall 16.
m polyethylene film 13 is coated. Side wall 1
Paperboard for 4 has a basis weight of 170g / m ² ~310g / m
^{2. The} thickness is set to 220 μm to 420 μm. Further, the thickness of the polyethylene film 13 is set to 20 μm to 60 μm.

As shown in FIG. 3, the surface of the polyethylene film 13 on the inner surface of the side wall 14 is matted 13a and has a ten-point average roughness (JIS B0601) of 10 μm to 3 μm.
It is set to 0 μm. If the ten-point average roughness by the mat processing 13a is smaller than this range, blocking is likely to occur, and if it is larger than this range, the mat processing itself becomes difficult. The ten-point average roughness was 13
Is set to 60% or less of the thickness of If the thickness exceeds this range, pinholes are likely to be formed in the polyethylene film 13, and the reliability with respect to waterproofness decreases. Note that, instead of the polyethylene film 13, another resin film such as a polyester film can be used.

The embossed paper 24 is made of white bleached kraft paper and has a basis weight of 120 g / m ² . Embossed paper 2
An emboss 25 is formed on the entirety of 4 and is composed of a number of points arranged as a lattice inclined at about 45 degrees with respect to the central axis of the cup body 12. The embossed paper 24 is embossed 25
However, it must have a strength that does not collapse under normal use, but must be easy to process. From this viewpoint, the desirable range of the basis weight of the embossed paper 24 is 50 / m
^{2 to} 180 g / m ² . Paper having a large fiber length, such as bleached kraft paper, has the advantage that it is difficult to make holes when embossing is formed.

The shape and dimensions of the emboss 25 will substantially define the insulating air layer formed in the protective cover 20. In consideration of both the heat insulating property and the heat retaining property of the heat insulating cup, the desirable range of the diameter of the projections and the depressions of the dot pattern is 2 mm to 5 mm. The desirable range of the height of the emboss 25 (the difference in height between the convex portion and the concave portion) is 1 mm to 5 mm.
mm. A desirable range of the density of the emboss 25 is 3 / cm ^{2 to} 25 / cm ² in total of the convex portions and the concave portions. As the pattern of the emboss 25, other patterns such as a rectangular lattice pattern composed of a large number of rectangles having substantially the same size as the circular point, a corrugated pattern, etc. can be adopted instead of the above-mentioned circular point lattice pattern.

The basis weight of the liner paper 28 is 230 g / m ^2.
On the front side, characters or designs relating to the product are applied by offset printing or gravure printing. A desirable range of the basis weight of the liner paper 28 is 180 g / m ² to 2 g.
70 g / m ² . If it is more than this range, the rigidity becomes too high, and the workability of the protective cover 20 decreases. If it is less than this range, the rigidity and strength are reduced, and irregularities following the emboss 25 are generated on the surface, or the protective cover 20 is easily broken during transportation or storage after being attached to the cup body 12. As shown in FIG. 3, an ink layer 32 for displaying characters and patterns is formed on the liner paper 28, and a varnish layer 34 having a thickness of 3 μm to 15 μm is formed so as to cover the entire liner paper 28. . The surface of the varnish layer 34 is finished smoothly. The varnish layer 34 is formed of, for example, an OP (overprinting) varnish, a release varnish, or the like.

The members of the cup body 12, the embossed paper 24, and the liner paper 28 are adhered with synthetic glue, for example, vinyl acetate glue, ethylene vinyl acetate (EVA) glue. In addition, various known pastes can be used as the paste. For example, starch-based glue can be used, but in this case, the surface of the liner paper 28 is likely to have irregularities imitating the emboss 25. Therefore, it is desirable to use the above-mentioned vinyl acetate glue and ethylene vinyl acetate glue.

As described above, in this embodiment, the inner surface of the side wall 14 of the cup body 12 has a ten-point average roughness of 10 μm to 3 μm.
Polyethylene membrane 1 having a relatively rough surface of 0 μm
3 or the like. For this reason, even when the cups are nested one on top of the other, the cups are separated well despite the protective cover 20 having high elasticity. Moreover, since the outer surface of the liner paper 28 is covered with the varnish layer and is smooth, the cup separation is further improved.

An experiment was conducted to confirm the effects of the present invention and to examine the relationship between the mat processing on the surface of the polyethylene film 13 and the varnish layer on the outer surface of the liner paper 28. In the experiment, the static friction force and the static friction coefficient between the polyethylene film having the matted surface and the varnish layer having the smooth surface were measured in accordance with JIS-K7125. In each of the used samples A to D, the ten-point average roughness (μm) of the surface of the polyethylene film and the type of the varnish layer
These are shown in the columns of [roughness] and [varnish layer] in Table 1, respectively. Samples A and B correspond to the insulating cups according to the present invention, and samples C and D correspond to the conventional insulating cups. The static friction force (gf) and the static friction coefficient obtained by the experiment are shown in the columns of [Static friction force] and [Static friction coefficient] in Table 1, respectively.

[0019]

[Table 1]

From Table 1, it can be seen that Samples A and B according to the present invention have smaller static friction coefficients than Samples C and D. That is, it has been demonstrated that the heat insulating cup according to the present invention can obtain better cup separating characteristics than the conventional heat insulating cup.

Next, a method of manufacturing a heat insulating cup according to an embodiment of the present invention will be described. First, a raw material sheet for the side wall 14 of the cup body 12 is prepared. As shown in FIG. 5, while extruding the base paper 40 from the sheet roll 42, the molten polyethylene is supplied in the extruder 44, and the base paper 40 is coated with a polyethylene film. Subsequently, when the polyethylene film is cooled by the cooling roller 46, the surface of the polyethylene film is matted. For this reason, the surface of the cooling roller 46 is subjected to a predetermined matting process in advance, and the surface of the polyethylene film is formed into irregularities so as to transfer this. The raw material sheet thus prepared is wound up as a sheet roll 48.

Next, the cup body 12 is formed by a known cup forming apparatus. Here, first, the side wall 14 rounded into a truncated cone and the shallow cylindrical bottom wall 16 are combined,
A prototype of the cup body 12 is formed. Next, the cup body 1
The side wall 14 is turned outward at the periphery of the opening end of No. 2 to form a flange portion 18.

On the other hand, the protective cover 20 is formed in a system in which a known roll embossing device, a bonding device, and a punching device are combined. Therefore, a raw sheet roll of white bleached kraft paper, which is a raw material of the embossed paper 24, and a raw sheet roll of the liner paper 28 are set in the same system. The surface of the raw material sheet of the liner paper 28 is printed in advance by offset printing. By this printing, characters and designs relating to the product corresponding to the multiple protective covers 20 are applied to the surface of the raw material sheet of the liner paper 28.

First, a material sheet of embossed paper 24 is prepared by forming an emboss 25 while feeding the sheet from a sheet roll of bleached kraft paper. Next, glue, for example, vinyl acetate glue is applied to one side of the raw material sheet of the embossed paper 24. The application of the glue can be performed continuously after the formation of the emboss 25 or can be performed simultaneously with the formation of the emboss 25.

In synchronization with the feeding of bleached kraft paper,
The sheet is fed from the sheet roll of the liner paper 28. Then, this is superimposed on the glued surface of the raw material sheet of the embossed paper 24 and bonded by a clearance roller and a pressure belt.

Next, the raw material sheet of the embossed paper 24 and the liner paper 28 stuck is cut into a sheet of a predetermined width, and thereafter, it is sequentially cut and cut in accordance with characters and designs on the liner paper 28. As a result, it is possible to obtain a molded blank of the sector-shaped protective cover 20 having a size adapted to a size around the side surface of the cup body 12.

Next, the protective cover 20 is attached to the side wall 14 of the cup body 12. This can be performed, for example, by attaching the protective cover 20 around the side surface of the cup body 12 with glue using a winding device. When this winding method is adopted, the protective cover 2
No. 0 can be attached to the cup body 12 in a state where the both side end portions abut each other without overlapping.

In place of the method of winding the protective cover 20, the side wall 1 of the cup body 12 is
A method of assembling into a substantially frustoconical cylinder similar to 4 and then attaching the protective cover 20 while fitting it into the cup body 12 can also be adopted. In this case, an adhesive margin is provided on one side end of the molded blank of the protective cover 20, and the protective cover 20 is formed in a state where both side ends are overlapped.

[0029]

According to the heat insulating cup of the present invention, since the inner surface of the side wall of the cup body is covered with the resin film subjected to the coarse mat processing, even when the cups are nested one another, Despite the high elasticity of the protective cover, the cup separation is good. Moreover, when the outer surface of the protective cover is covered with the varnish layer and is smooth, the cup separation is further improved. Further, since the ten-point average roughness of the resin film surface is set to 60% or less of the thickness of the resin film, no pinhole is generated here.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a state where a heat insulating cup and a lid according to an embodiment of the present invention are separated.

FIG. 2 is a partially cutaway front view showing the heat insulating cup according to the embodiment of the present invention.

FIG. 3 is a sectional view showing a side wall of a cup body of the heat insulating cup according to the embodiment of the present invention.

FIG. 4 is a sectional view showing the liner paper of the heat insulating cup according to the embodiment of the present invention.

FIG. 5 is a schematic view showing an apparatus for preparing a raw material sheet on a side wall of a cup body.

[Explanation of symbols]

10: lid, 12: cup body, 13: polyethylene film,
14 ... side wall, 16 ... bottom wall, 18 ... flange portion, 20 ... protective cover, 24 ... embossed paper, 25 ... embossed 28 ... liner paper, 32 ... ink layer, 34 ... varnish layer.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-239627 (JP, A) JP-A-6-182940 (JP, A) JP-A-5-7614 (JP, U) Field (Int.Cl. ⁷ , DB name) B65D 81/38 B65D 3/22

Claims (2)

(57) [Claims] 1. An insulating cup comprising: a cup body having a paper side wall and a paper bottom wall; and a paper protective cover covering the side wall and affixed thereto. Is coated with a resin film having a thickness of 20 μm to 60 μm, the surface of the resin film is matted, and the ten-point average roughness is 10 μm to 30 μm and is 60% or less of the thickness of the resin film. Insulated cup characterized by. 2. The heat insulating cup according to claim 1, wherein an outer surface of the protective cover is covered with a varnish layer and is smooth.