JP6651734B2 - Microwave paper cup - Google Patents

Description

  The present invention relates to a microwave paper cup (paper container). The use of the microwave oven does not mean that the microwave oven is used only for the microwave oven, but means that the microwave oven can be used.

  Paper cups are widely used not only for instant foods and snacks, but also for beverages and prepared foods. In some cases, foods, drinking water and the like are put in these paper cups and heated and cooked in a microwave oven.

  When the paper cup containing the contents is heated and cooked in a microwave oven, there is a problem that the so-called threaded portion formed by extending the lower end of the body of the paper cup may be scorched. In particular, it is considered that the calorific value increases (the heat radiation amount does not increase) at the joining portion where the paper overlaps, the heat easily accumulates, and the scorch easily occurs. On the other hand, since the generated heat is taken away by the contents in the portion in contact with the contents, scorching hardly occurs.

  Patent Document 1 discloses a microwave oven paper cup including a body portion and a bottom portion, wherein a lower end portion (stringing) of the body portion is bent inward, and is joined to a peripheral portion of the bottom portion so as to cover from an outer surface. Has been described. Patent Literature 2 discloses a microwave-compatible paper cup in which an annular leg is formed by curling a joint portion between a body and a bottom inward.

JP 2003-81358 A JP-A-2003-192043

  By bending or curling the lower end of the body portion (stringing) inward to eliminate the stringing portion, it is possible to prevent the occurrence of scorching even when heated in a microwave oven. However, when the lower end of the trunk is bent inward, wrinkles are randomly generated at the bent portion. Since the bent portion is located at the bottom of the container, the flatness of the bottom surface of the cup deteriorates, and stability may be lacked when the cup is made to stand alone. In addition, random wrinkles 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.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide a flat bottom type paper cup which is hardly scorched even when used in a microwave oven and can be stably self-supported.

  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.

  A microwave paper cup according to the present invention has a cylindrical body and a bottom closing a lower end of the body, and the lower end of the body is bent inward so as to cover an outer surface of a peripheral edge of the bottom. And a plurality of ruled lines extending in a direction toward the center of the bottom are formed at equal angular intervals in a joint covering the outer surface of the bottom.

  A plurality of ruled lines (grooves, dents) extending in the direction toward the center of the bottom are formed at equal angular intervals at the joint (the lower end of the bent trunk) covering the outer surface of the bottom of the paper cup. The ruled line is formed before the joint is bent to cover the bottom outer surface.

  If the joint is bent inward toward the bottom outer surface without any treatment, the bent joint will wrinkle randomly. If wrinkles are randomly formed at the joints, the flatness of the bottom surface of the cup becomes poor, and stability may be lacked when the cup is made to stand alone. According to the present invention, since a plurality of ruled lines extending in the direction toward the center of the bottom are regularly formed at the joint, the excess portion of the joint (the inwardly bent portion) bent inward by the regularly arranged ruled lines is formed. The occasional wrinkles) are absorbed, and no random wrinkles are formed at the joints. A paper cup having a substantially flat bottom surface is formed. Since the paper cup according to the present invention has a substantially flat bottom surface, it can stably stand alone. Also, since the joint is along the outer surface of the bottom of the paper cup, it does not easily burn when heated in a microwave oven.

  Further, the joint portion covering the outer surface of the bottom of the paper cup surely adheres to the outer surface of the bottom of the paper cup in an area where the ruled line is formed. Since the plurality of ruled lines are regularly formed throughout the joint, the joint can be firmly joined to the bottom outer surface of the paper cup over the entire bottom of the paper cup. The problem of poor adhesion between the bottom outer surface of the paper cup and the joint is less likely to occur.

  In one embodiment, a heat insulating layer is provided on the outermost layer at the bottom of the paper cup. Even if hot contents are placed in a paper cup or the contents are heated up hot by a microwave oven, even if touched by a finger, it does not feel hot.

  A heat insulation layer may be provided on at least one of the outer surface and the inner surface of the body of the paper cup. A heat insulation effect (thermal insulation effect) can be expected. Also, it is not necessary to feel the heat when touching the torso by hand.

  In another embodiment, an outer cylinder member is placed over and fixed to the outside of the body. Also in this embodiment, a heat insulating effect (thermal insulation effect) can be expected, and no heat is felt when the body is touched.

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

It is a partially broken front view of a microwave oven paper cup. FIG. 2 is a bottom view of the microwave paper cup along the line II-II in FIG. 1. 1 shows a manufacturing process of a paper cup. 1 shows a manufacturing process of a paper cup. FIG. 5 is an enlarged sectional view taken along line VV of FIG. 4. It is sectional drawing of the paper cup lower part which shows the modification of the junction part of a trunk | drum member and a bottom member. It is sectional drawing of the paper cup lower part which shows the other modification of the junction part of a trunk | drum member and a bottom member. It is sectional drawing of the paper cup lower part which shows another modification of the junction part of a trunk | drum member and a bottom member. It is a partially broken front view of the microwave oven paper cup which covered the outer cylinder member. It is a partially broken front view of another microwave oven paper cup which covered the outer cylinder member. It is a partially broken front view of the microwave oven paper cup of a modification. It is the elements on larger scale of the paper cup shown in FIG. It is a partially broken front view of the microwave paper cup of other modification. It is the elements on larger scale of the paper cup shown in FIG.

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

  FIG. 1 is a partially cutaway front view showing a microwave oven paper cup according to an embodiment of the present invention. FIG. 2 is a bottom view of the microwave oven paper cup along the line II-II in FIG. In FIG. 1, for the sake of simplicity, the thickness of the members constituting the paper cup is emphasized.

  The microwave paper cup 10 includes a body member 11 mainly made of paper and a bottom member 12. The body member 11 has a cylindrical shape in which the diameter at the top is large and the diameter decreases as it goes down. The upper end portion of the body member 11 is wound outward (in a direction away from the portion where the contents of the paper cup 10 enters, that is, outward) to form a so-called curled portion (top curled portion) 11A. The curl portion 11A is covered with a lid (not shown) or joined (adhered, welded).

  The lower end of the body member 11 is bent inward (inward toward the portion into which the contents of the paper cup 10 enters, inward) at a substantially right angle (the bent portion is indicated by reference numeral 11B). It is folded (the folded portion is indicated by reference numeral 11C). The bottom member 12 has a circular shape, and its peripheral edge portion 12A fits snugly within the lower end of the body member 11. The peripheral 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 of the body member 11 and the folded portion 11C. Have been. These sandwiched portions 12A, 11C, 12B, 11B are joined (adhered, welded) (fixed) to each other at least partially, preferably entirely. Depending on the contents, the inner surface and / or the outer surface of the body member 11 and the bottom member 12 are coated with a protective film (resin film, resin film, etc.) as necessary. Specific examples of the protective film include, for example, polyethylene (PE), polypropylene (PP), polyester, ethylene / vinyl acetate copolymer, and the like. They also have the advantage that they can be used for bonding by heat sealing.

  A bent portion 11B and a folded portion 11C of the body member 11 and a folded portion 12B of the bottom member 12 are joined to the outer peripheral portion of the outer surface of the bottom member 12 of the paper cup 10 in a ring shape. Hereinafter, the entire annular portion joined to the peripheral portion of the outer surface of the bottom member 12 of the paper cup 10 is referred to as “annular joint 20”.

  Referring to FIG. 2, when viewing the bottom surface of the paper cup 10, it is confirmed that the annular joint portion 20 is annularly provided on the outer peripheral portion of the bottom member 12. On the surface of the annular joint 20, 32 ruled lines 25 are formed annularly at equal angular intervals. Each of the ruled lines 25 extends in a direction toward the center of the bottom member 12. If the center of the bottom member 12 is used as a reference, it can be expressed that each ruled line 25 extends radially from the center. The number of ruled lines 25 can be adjusted as appropriate.

  The manufacturing process of the paper cup 10 will be described with reference to FIGS. 3 and 4 show the paper cup in an upside-down state. FIG. 5 is an enlarged sectional view taken along line VV of FIG.

  With reference to FIG. 3, a paper cup with a so-called thread binding, in which the annular joint 20 is not bent, is first created.

  Referring to FIGS. 4 and 5, a press die having a length (edge length) of about 1 cm and having a sharp tip is pressed from the outside of the annular joint portion 20 at equal angular intervals and pressed. A ruled line (recess, groove) 25 is formed in the pressed portion. For example, 32 ruled lines 25 are formed in the annular joint portion 20 in an annular manner at equal angular intervals with the adjacent ruled lines 25. By being pressed from the outside, the entire annular joint 20 is slightly inclined inward.

  Ultrasonic pressing is performed from the outside of the annular joint portion 20 inclined inward. The annular joint 20 is completely bent and joined to the bottom member 12. A microwave paper cup 10 having a substantially flat bottom surface (see FIG. 2) is completed. When bent by the ultrasonic press, the ruled line (recess) 25 formed in the annular joint portion 20 is crushed from both sides, so that the ruled line 25 looks like a streak (line) in the completed paper cup 10.

  If the annular joint 20 is simply bent inward without performing any processing, the annular joint 20 is randomly wrinkled due to the surplus portion. If wrinkles are randomly formed, the bottom of the cup (the surface of the annular joint 20) is unlikely to be flat, and the cup lacks a sense of stability when it becomes independent. On the other hand, since a plurality of ruled lines 25 are regularly arranged at equal angular intervals in the above-described paper cup 10, an excess portion when the annular joint portion 20 is bent inward by the regularly arranged ruled lines 25 is formed. Since it is absorbed, random wrinkles do not occur at the annular joint 20. The paper cup 10 becomes stable independently.

  By pressing the annular joint 20 from the outside by an ultrasonic press, a considerably wide area inside the annular joint 20 is in close contact with the bottom member 12 of the paper cup 10. In the range in which the ruled line 25 is formed, the paper cup 10 securely adheres to the bottom member 12 of the paper cup 10. For this reason, the problem of poor adhesion between the bottom member 12 and the annular joint portion 20 hardly occurs. Further, since the paper cup 10 does not have a twist, it is hard to scorch even when heated in a microwave oven.

  6 and 7 show a modified example of the annular joint (bend). In this modification, a peripheral portion 12A of the bottom member 12 is folded outward, and a bent portion 11B at the lower end of the body member 11 is bonded or welded to the outer surface of the folded portion 12B. In the modification shown in FIG. 6, the length of the bent portion 11B of the body member 11 is long, and the entire folded portion 12B of the bottom member 12 is covered by the bent portion 11B of the body member 11 at the annular joint 20A. In the modification shown in FIG. 7, the length of the folded portion 12B of the bottom member 12 is long at the annular joint 20B. Of course, the length of the bent portion 11B of the trunk member 11 and the length of the folded portion 12B of the bottom member 12 are adjusted so that the end surface of the bent portion 11B of the trunk member 11 and the end surface of the folded portion 12B of the bottom member 12 are flush. May be.

  FIG. 8 shows still another modification. In this modification, a heat insulating layer 31 is provided on the outer surface of the bottom member 12. The heat insulating layer 31 is made of, for example, foamed plastic such as low-density polyethylene mixed with a foaming agent (such as sodium hydrogen carbonate). Foaming occurs when the foamed plastic mixed with the foaming agent is heated. In addition, the foaming is performed after the paper cup 10 is formed, 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 a paper cup 10 containing hot contents or a paper cup 10 heated by a microwave oven is held by hand, even if a finger touches the bottom, no heat is felt.

  FIG. 9 shows still another modification, in which a body member 11 is covered with an outer cylinder member 13. The outer cylinder member 13 is a cylindrical body having a slightly larger diameter at an upper portion than at a lower portion, and has a lower end folded inward (a 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 a 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 position of the curled portion 11A and the position of the folded portion 13A.

  By providing the outer cylinder member 13 outside the body member 11, the user does not feel the heat when holding the body of the paper cup 10 by hand. In addition, the heat insulation (heat retention) of the entire paper cup is also improved.

  As shown in FIG. 10, a curl portion 13 </ b> B that is wound inside may be formed at the lower end portion of the outer cylindrical 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. 11 shows a modified paper cup 10A in which a heat insulating layer 32 is provided on the outer surface of the body member 11. FIG. 12 is an enlarged view of a part of the paper cup 10A of the modified example shown in FIG. The heat insulating layer 32 is formed by foaming low-density polyethylene, for example. Foaming is performed after the paper cup 10A is formed, and foaming at a joint portion such as the folded portion 12B is suppressed. When the paper cup 10A containing the hot contents or the paper cup 10A heated by the microwave oven is held by hand, it is not necessary to feel the heat. In addition, a heat retaining effect can also be expected.

  When the body member 11 (paper layer) is heated, moisture contained in the body member 11 evaporates. The moisture evaporated from the body member 11 can be used to foam the low-density polyethylene. In order to prevent the evaporating water from escaping, a water vapor barrier 33, for example, a medium density polyethylene, is preferably provided on the inner surface of the body 11 so that the water contained in the body 11 can be reduced to 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 (front surface) of the heat insulating layer 32.

  FIG. 13 shows a modified paper cup 10B in which a heat insulating layer 34 is provided on the inner surface of the body member 11. FIG. 14 is an enlarged view of a part of the paper cup 10B of the modification shown in FIG. For example, a polyethylene layer 34 containing a foaming agent (such as sodium bicarbonate) is laminated on the inner surface of the body member 11, and a polyethylene layer 35 containing no foaming agent is laminated on the inner surface. By heating, the polyethylene layer containing the foaming agent foams, and the heat insulating layer 34 is formed. Foaming at a joint portion such as the folded portion 12B is suppressed. Foaming can be suppressed by not heating around the flange 11A. A heat insulating layer may be provided on both the outer surface and the inner surface of the body member 11.

10,10A, 10B Microwave paper cup
11 Torso members
12 Bottom member
13 Outer cylinder member
20, 20A, 20B Annular joint
25 ruled lines
31, 32, 34 Insulation layer

Claims (5)

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 portion,
A plurality of ruled lines extending in the direction toward the center of the bottom are formed at equal angular intervals on the outer surface of the lower end of the body that is in close contact with the outer surface of the bottom.
Microwave paper cup. A heat insulation layer is provided on the outermost layer at 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. An outer cylinder member is placed over and fixed to the outside of the body;
The microwave oven paper cup according to claim 1. An inward turn is formed at the lower end of the outer cylinder member,
The microwave oven paper cup according to claim 4.

Images