JP6798589B2 - Microwave paper cup - Google Patents

Description

The present invention relates to a microwave oven paper cup (paper container). "For microwave ovens" does not mean that it is limited to microwave ovens only, but that it can be used in microwave ovens.

Paper cups are widely used not only as containers for instant foods and snacks, but also as containers for beverages and prepared foods. In some cases, these paper cups are heated and cooked in a microwave oven with food, drinking water, etc. in them.

When a paper cup containing the contents is heated and cooked in a microwave oven, there is a problem that the so-called threading portion formed by extending the lower end of the body of the paper cup may be burnt. In particular, it is considered that the amount of heat generated is large (the amount of heat radiation is not large) at the joint where the papers overlap, heat is easily stored, and charring is likely to occur. On the other hand, in the part in contact with the contents, the heat generated is taken away by the contents, so that charring is unlikely to occur.

Patent Document 1 describes a microwave oven paper cup composed of a body and a bottom, the lower end (threading) of the body is bent inward, and the peripheral edge of the bottom is joined so as to cover from the outer surface. Have been described. Patent Document 2 describes a microwave oven-compatible paper cup in which a joint portion between a body portion and a bottom portion is curled inward to form an annular leg portion.

Japanese Unexamined Patent Publication No. 2003-81358 Japanese Unexamined Patent Publication No. 2003-192043

By bending or curling the lower end of the body (threading) inward to eliminate the threading, it is possible to prevent the occurrence of charring even when heated in a microwave oven. However, when the lower end of the body is bent inward, wrinkles are randomly formed at the bent part. Since the bent part is located at the bottom of the container, the flatness of the bottom surface of the cup deteriorates, and the cup may lack stability when it is made to stand on its own. In addition, random wrinkles may cause a random gap between the bent portion and the bottom surface of the cup, which may cause a problem of poor adhesion between the bent portion and the bottom surface of the cup.

An object of the present invention is to provide a flat bottom type paper cup that does not burn easily even when used in a microwave oven and can stand on its own in a stable manner.

Another object of the present invention is to reduce the problem of poor adhesion between the bent portion and the bottom surface of the cup.

Microwave paper cup according to the present invention includes a cylindrical body portion, and a bottom portion closing the lower end of the body portion, the lower end portion of the barrel is bent inward, and in close contact with the outer surface of the bottom , the outer surface of the barrel bottom end in close contact with the bottom outer surface, a concave portion and convex portion is characterized in that it is formed with a plurality of alternately.

A plurality of concave and convex portions are alternately formed at the joint portion (the lower end portion of the bent body portion) that covers the outer surface of the bottom portion of the paper cup. Here, the unevenness of the concave portion and the convex portion shall be based on the case where the bottom of the cup is facing up. The convex portion protrudes outward more than the concave portion, and therefore the convex portion supports the paper cup when the paper cup is self-supporting. A plurality of convex portions (so as to sandwich the concave portion) intermittently throughout the joint provided Runode, paper cups according to the invention is free-standing and stable.

A slight step is formed between the plurality of concave portions and the convex portions. Since a plurality of concave and convex portions are alternately formed at the joint portion, the steps between the concave surface portion and the convex surface portion are regularly arranged at the joint portion. According to the present invention, a plurality of concave portions and a plurality of convex portions are alternately formed so that a plurality of steps are regularly formed at the joint portion. Random wrinkles are not formed at the joint because the excess portion of the joint bent inward (the portion that becomes wrinkled when bent inward) is absorbed by the plurality of steps. Random wrinkles do not interfere with the independence of the paper cup.

Further, the joint portion that covers the outer surface of the bottom of the paper cup is surely adhered to the outer surface of the bottom of the paper cup within the range of the concave surface. Like the convex portion, a plurality of concave portions are provided intermittently (so as to sandwich the convex portion) over the entire joint portion, so that the joint portion should be firmly joined to the outer surface of the bottom of the paper cup over the entire joint portion. Can be done. Therefore, the problem of poor adhesion between the outer surface of the bottom of the paper cup and the joint is unlikely to occur. It should be noted that the step between the concave surface and the convex surface of the joint is slight and is along the outer surface of the bottom of the paper cup as a whole, so that it is unlikely to be charred even when heated in a microwave oven.

In one embodiment, at each boundary between the concave portion and the convex portion, a fold portion (squeezing streak) that bites toward the base of the convex portion is formed in a direction toward the center of the bottom portion. Since the step between the concave portion and the convex portion can be formed in a squatted (crushed) form, the step between the concave portion and the convex portion can be reduced. The outer surface of the bottom of the paper cup can be made closer to an overall flat state.

In one embodiment, a heat insulating layer is provided on the outermost layer at the bottom of the paper cup. Even if you put hot contents in a paper cup or the contents are heated hot by a microwave oven, even if you touch them with your fingers, you will not feel the heat.

A heat insulating layer may be provided on at least one of the outer surface and the inner surface of the body of the paper cup. Insulation effect (heat retention effect) can be expected. Also, you don't have to feel the heat when you touch the body with your hands.

In another embodiment, the outer cylinder member is covered and fixed to the outside of the body portion. In this embodiment as well, a heat insulating effect (heat retention effect) can be expected, and the heat is not felt when the body is touched.

Preferably, an inward barb is formed at the lower end of the outer cylinder member. For example, the above return can be realized by folding the lower end of the outer cylinder member inward or curling the lower end of the outer cylinder member inward. Since a heat insulating space is secured between the body of the paper cup and the outer cylinder member, the heat insulating effect of the microwave oven paper cup can be further enhanced.

It is a partially broken front view of the microwave oven paper cup. It is a bottom view of the microwave oven paper cup along the line II-II of FIG. It is an enlarged sectional view of the annular joint part along the line III-III of FIG. The process of forming the annular joint is shown. The process of forming the annular joint is shown. The process of forming the annular joint is shown. It is sectional drawing of the lower part of the paper cup which shows the deformation example of the joint part of the body member and the bottom member. It is sectional drawing of the lower part of the paper cup which shows the other modification of the joint part of the body member and the bottom member. It is sectional drawing of the lower part of a paper cup which shows still another modification of the joint part of a body member and a bottom member. It is a partially broken front view of the microwave oven paper cup covered with the outer cylinder member. It is a partially broken front view of another microwave oven paper cup covered with an outer cylinder member. It is a partially broken front view of the microwave oven paper cup of a modification. It is a partially enlarged view of the paper cup shown in FIG. It is a partially broken front view of the microwave oven paper cup of another modification. It is a partially enlarged view of the paper cup shown in FIG.

Hereinafter, the microwave oven paper cup according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is a front view showing a part of a microwave oven paper cup according to an embodiment of the present invention in a broken state. FIG. 2 is a bottom view of the microwave oven paper cup along the line II-II of FIG. FIG. 3 is an enlarged cross-sectional view taken along the line III-III of FIG. In FIGS. 1 and 3, the thickness of the members constituting the paper cup is emphasized for the sake of clarity.

The microwave oven paper cup 10 is composed of a body member 11 and a bottom member 12 whose main strength material is paper. The body member 11 has a cylindrical shape with a large diameter at the top and a small diameter at the bottom. The upper end portion of the body member 11 is wound outward (direction away from the portion of the paper cup 10 in which the contents enter, outward), and a so-called curl portion (top curl portion) 11A is formed. The curl portion 11A is covered with a lid (not shown) or joined (bonded or welded).

The lower end of the body member 11 is bent at a right angle to the inside (direction toward the part where the contents of the paper cup 10 are inserted, inward) (the bent portion is indicated by reference numeral 11B), and the tip of the bent portion 11B is inward. It is folded (the folded part is indicated by reference numeral 11C). The bottom member 12 is circular, and its peripheral edge portion 12A fits snugly into the lower end portion of the body member 11. The peripheral edge portion 12A of the bottom member 12 is folded outward (the folded portion is indicated by reference numeral 12B), and the folded portion 12B of the bottom member 12 is sandwiched between the bent portion 11B and the folded portion 11C of the body member 11. It has been. These portions 12A, 11C, 12B, and 11B sandwiching each other are joined (bonded, welded) (fixed) to each other at least partially, preferably completely. Depending on the contents, a protective film (resin film, resin film, etc.) is coated on the inner surface and / or outer surface of the body member 11 and the bottom member 12 as needed. Specific examples of the protective film include polyethylene (PE), polypropylene (PP), polyester, ethylene-vinyl acetate copolymer and the like. These also have the advantage that they can also be used for bonding by heat sealing.

On the peripheral edge of the outer surface of the bottom member 12 of the paper cup 10, the bent portion 11B and the folded portion 11C of the body member 11 and the folded portion 12B of the bottom member 12 are joined in an annular shape. Hereinafter, the entire annular portion to be joined to the peripheral edge of the outer surface of the bottom member 12 of the paper cup 10 will be referred to as “annular joint 20”.

Looking at the bottom surface of the paper cup 10 with reference to FIG. 2, it is confirmed that the annular joint portion 20 is provided in an annular shape on the peripheral edge of the outer surface of the bottom member 12. On the surface of the annular joint portion 20, substantially rectangular concave surface portions 21 and convex surface portions 22 are alternately formed and arranged in an annular shape. The widths of the concave surface portion 21 and the convex surface portion 22 (the length in the annular direction) are almost the same, or the width of the concave surface portion 22 is slightly longer. In the paper cup 10 of this embodiment, 16 concave portions 21 and 16 convex portions 22 are alternately arranged. The number of concave portions 21 and convex portions 22 can be adjusted as appropriate.

With reference to FIG. 3, the surfaces of the plurality of concave surface portions 21 are at substantially the same height position, and the surfaces of the plurality of convex surface portions 22 are also at substantially the same height position. The convex portion 22 protrudes slightly outward (that is, toward the bottom of the paper cup 10) from the concave portion 21. Further, the boundary between the concave surface portion 21 and the convex surface portion 22 is slightly inclined so as to bite toward the base 26 of the convex surface portion 22. The portion that bites into the base 26 of the convex portion 22 at the boundary between the concave portion 21 and the convex portion 22 is hereinafter referred to as a “folded portion 25”. The concave portion 21 and the convex portion 22 slightly overlap each other due to the folded portion 25, and the step between the concave portion 21 and the convex portion 22 is considerably reduced. When viewed from the bottom surface, the folded portion 25 at the boundary between the concave surface portion 21 and the convex surface portion 22 looks like a short streak (ruled line) extending in the direction toward the center of the bottom member 12 (see FIG. 2). When 16 concave portions 21 and 16 convex portions 22 are arranged alternately, 32 folding portions 25 appear at equal angular intervals in the annular joint portion 20.

If the annular joint 20 is simply bent inward without any treatment, the annular joint 20 will be randomly wrinkled due to the excess portion. Random wrinkles make it difficult for the bottom of the cup (the surface of the annular joint 20) to flatten, resulting in a lack of stability when the cup is self-supporting. On the other hand, in the above-mentioned paper cup 10, 16 concave portions 21 and 16 convex portions 22 are regularly formed alternately and arranged in an annular shape, and the folded portions 25 are also regularly arranged at equal angular intervals. They are lined up. The surface of the convex portion 22 is at approximately the same height position, and this is regularly present over the entire circumference of the annular joint portion 20. Further, since the excess portion when the annular joint portion 20 is bent inward is absorbed by the step (folded portion 25) between the concave surface portion 21 and the convex surface portion 22, random wrinkles do not occur in the annular joint portion 20. The paper cup 10 will be stable and self-supporting.

With reference to FIG. 3, at the concave portion 21, the annular joint portion 20 (folded portion 11C of the body member 11) is in close contact with the peripheral edge portion 12A of the bottom member 12 of the paper cup 10, and is in close contact with the peripheral portion 12A. The annular joint portion 20 and the bottom member 12 of the paper cup 10 can be firmly joined. Since the concave surface portions 21 are regularly present at equal intervals over the entire circumference of the annular joint portion 20, the problem of poor adhesion between the bottom member 12 and the annular joint portion 20 is unlikely to occur. Furthermore, since the paper cup 10 does not have twisting, it does not easily burn even when heated in a microwave oven.

4 to 6 show the manufacturing of the above-mentioned paper cup 10. 4 to 6 show the paper cup 10 in an upside down state.

With reference to FIG. 4, first, a paper cup having a so-called thread twist, in which the annular joint 20 is not bent, is created.

With reference to FIG. 5, a stamp having a width obtained by dividing the peripheral length of the annular joint 20 into, for example, 32 is pressed from the outside of the annular joint 20 at predetermined intervals to press. The pressed portion becomes the concave portion 21, and the unpressed portion becomes the convex portion 22. In the annular joint portion 20, 16 concave surface portions 21 and 16 convex surface portions 22 are alternately formed in an annular shape. By being pressed from the outside, the entire annular joint 20 is slightly tilted inward.

With reference to FIG. 6, the ultrasonic press is performed from the outside of the annular joint 20 inclined inward. The annular joint 20 is completely bent and joined to the bottom member 12. Further, a folding portion 25 is formed at the boundary between the concave surface portion 21 and the convex surface portion 22. A microwave oven paper cup 10 with a flat bottom is completed.

7 and 8 show a modified example of the annular joint (bent portion). In this modification, the peripheral edge portion 12A of the bottom member 12 is folded outward, and the bent portion 11B at the lower end portion of the body member 11 is adhered or welded to the outer surface of the folded portion 12B. In the modified example shown in FIG. 7, the length of the bent portion 11B of the body member 11 is long, and in the annular joint portion 20A, the entire folded portion 12B of the bottom member 12 is covered by the bent portion 11B of the body member 11. On the contrary, in the modified example shown in FIG. 8, the length of the folded portion 12B of the bottom member 12 is long in the annular joint portion 20B. Of course, the lengths of the bent portion 11B of the body member 11 and the folded portion 12B of the bottom member 12 are adjusted so that the end surface of the bent portion 11B of the body member 11 and the end surface of the folded portion 12B of the bottom member 12 are flush with each other. You may.

FIG. 9 shows yet another modification. In this modification, the heat insulating layer 31 is provided on the outer surface of the bottom member 12. The heat insulating layer 31 is made of foamed plastic such as low-density polyethylene mixed with a foaming agent (sodium hydrogen carbonate or the like). Foaming occurs by heating the foamed plastic mixed with the foaming agent. The foaming is performed after the paper cup 10 is molded, and the foaming of the joint portion such as the folded portion 12B is suppressed. By providing the heat insulating layer 31 on the bottom member 12, when the paper cup 10 containing the hot contents or the paper cup 10 heated in the microwave oven is held by hand, the heat is not felt even if the finger touches the bottom.

FIG. 10 shows still another modification, in which the body member 11 is covered with the outer cylinder member 13. The outer cylinder member 13 is a tubular body having a diameter slightly larger than that of the lower portion, and the lower end portion is folded inward (folded portion 13A). The body member 11 having the bottom member 12 is completely inserted (fitted) into the outer cylinder member 13 from above. The upper end of the outer cylinder member 13 enters the gap inside the curl portion 11A of the body member 11. A heat insulating space (gap) is formed between the outer surface of the body member 11 and the inner surface of the outer cylinder member 13. The outer cylinder member 13 is fixed to the body member 11 with an adhesive at one or both of the curl portion 11A and the folded portion 13A.

By providing the outer cylinder member 13 on the outside of the body member 11, the heat is not felt even when the body portion of the paper cup 10 is held by hand. In addition, the heat insulation (heat retention) of the entire paper cup 10 is also improved.

As shown in FIG. 11, a curl portion 13B that is wound inward may be formed at the lower end portion of the outer cylinder member 13. The heat insulating space (gap) between the outer surface of the body member 11 and the inner surface of the outer cylinder member 13 can be increased.

FIG. 12 shows a modified example paper cup 10A in which the heat insulating layer 32 is provided on the outer surface of the body member 11. FIG. 13 shows an enlarged part of the paper cup 10A of the modified example shown in FIG. The heat insulating layer 32 is formed by, for example, foaming low density polyethylene. Foaming is performed after forming the paper cup 10A, and foaming of the joint portion such as the folded portion 12B is suppressed. You do not feel the heat when you hold the body of the paper cup 10A containing the hot contents or the paper cup 10A heated in the microwave oven by hand. In addition, a heat retaining effect can be expected.

When the body member 11 (paper layer) is heated, the water contained in the body member 11 evaporates. The water that evaporates from the body member 11 can be used to foam the low density polyethylene. In order to prevent the evaporated water from escaping, a water vapor blocking layer 33, for example, medium density polyethylene is preferably provided on the inner surface of the body member 11, whereby the water contained in the body member 11 is removed from the low density polyethylene (low density polyethylene). It can be efficiently evaporated toward the heat insulating layer 32). A printing layer (ink layer) may be further formed on the outer surface (surface) of the heat insulating layer 32.

FIG. 14 shows a modified example paper cup 10B in which the heat insulating layer 34 is provided on the inner surface of the body member 11. FIG. 15 shows an enlarged part of the paper cup 10B of the modified example shown in FIG. For example, a polyethylene layer 34 containing a foaming agent (sodium hydrogen carbonate or the like) is laminated on the inner surface of the body member 11, and a polyethylene layer 35 containing no foaming agent is further laminated on the inner surface thereof. By heating, the polyethylene layer containing a foaming agent foams to form a heat insulating layer 34. Foaming of the joint portion such as the folded portion 12B is suppressed. Further, foaming can be suppressed by not heating the vicinity of the flange 11A. Insulation layers can also be provided on both the outer and inner surfaces of the body member 11.

10, 10A, 10B microwave oven paper cup
11 Body member
12 Bottom member
13 Outer cylinder member
20, 20A, 20B annular joint
21 Concave part
22 Convex surface
25 Folded part
26 Root
31, 32, 34 Insulation layer

Claims (5)

It has a tubular body and a bottom that closes the lower end of the body, and the lower end of the body is bent inward and is in close contact with the outer surface of the bottom.
The outer surface of the body portion lower end in close contact with the outer bottom surface, and a concave portion and convex portion is formed with a plurality alternately,
At each of the boundaries between the concave surface portion and the convex surface portion, a folding portion that bites toward the base of the convex surface portion is formed in a direction toward the center of the bottom portion.
Microwave paper cup. A heat insulating layer is provided on the outermost layer of the bottom.
The microwave oven paper cup according to claim 1. A heat insulating layer is provided on at least one of the outer surface and the inner surface of the body.
The microwave oven paper cup according to claim 1. The outer cylinder member is covered and fixed on the outside of the body.
The microwave oven paper cup according to claim 1. An inward barb is formed at the lower end of the outer cylinder member,
The microwave oven paper cup according to claim 4 .

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