CN1268525C - Paper cup for microwave oven, paper cup applicable to microwave oven and method for producing the same - Google Patents

Abstract

A paper cup for microwave oven in which a content, e.g. drink or instant food, placed in the paper cup does not leak when it is heated in a microwave oven and the paper cup is not scorched at any portion. The paper cup (A) for microwave oven is formed by folding a thread bottom part (3) bonding the body member (1) and the bottom member (2) of a paper cup (a) inward. Bottom face of the bottom member (2) is recessed inward.

Description

Paper cup for microwave oven and manufacturing method thereof

technical field

The invention relates to a paper cup used in a microwave oven.

Background technique

Conventionally, paper cups have been widely used as containers for hot drinks or convenience foods in vending machines. In addition, there are also paper cups containing non-common beverages or home-cooked dishes directly by microwave ovens for heating and cooking.

However, when a general-shaped paper cup is filled with contents and heated and cooked, scorching may occur at the undercut portion of the bottom of the paper cup. The reason for this can be considered as follows. The cellulose of the pulp material basically absorbs the microwaves of the microwave oven. Therefore, in the overlapping part of the paper, increasing the thickness of the paper increases the heat generation. However, since the undercut portion has a small surface area and generates little heat, generated heat is accumulated in the undercut portion. Therefore, the temperature of the undercut portion rises, causing scorching. However, when there is content, the heat accumulated on the paper is taken away by the content, making it difficult to cause scorching. In addition, microwaves are irradiated from both inside and outside of the undercut part, which is also the cause of scorching. In short, a common paper cup, as shown in FIG. 32, has an undercut portion 3 at the junction of the cup body part 1 and the cup bottom part 2. The undercut part 3 does not come into contact with the content and is easy to store heat. And it is easy to burn due to being irradiated by microwaves from both inside and outside.

In order to solve this problem, Japanese Unexamined Patent Publication No. 11-11541 discloses a paper cup for a microwave oven without an undercut shape. In fact, as shown in FIG. 33 , no scorching was observed in the paper cup for a microwave oven without the shape of the undercut portion.

However, compared with the situation where the undercut portion is provided at the junction of the cup body member 1 and the cup bottom member 2, there are still deficiencies in using a paper cup for a microwave oven without an undercut shape, and there is a possibility of leakage due to the contents. question.

Contents of the invention

The object of the present invention is to provide a paper cup for a microwave oven that does not leak and does not burn any part of the paper cup and its manufacturing method when the beverage or instant food is added to the paper cup and heated and cooked in a microwave oven.

As a result of studying to solve the above-mentioned problems, the first paper cup for microwave ovens of the present invention has an undercut portion on a paper cup provided with a cup body member and a cup bottom member, and combines the above-mentioned cup body member and the above-mentioned cup bottom member, Fold the undercut part inward to form it. In this paper cup for a microwave oven, the bottom surface of the cup bottom member may be formed in a concave shape inwardly.

According to the first paper cup for microwave ovens of the present invention, by folding the undercut portion of the paper cup inward, it can be obtained that when the contents such as beverages or instant food are added to the paper cup and heated and cooked in a microwave oven, the contents will not leak and the paper cup will not leak. No burnt microwave paper cups are produced in any part of the product.

The second paper cup for microwave ovens of the present invention has an undercut part on a paper cup provided with a cup body part and a cup bottom part, and the undercut part of the above-mentioned cup body part and the above-mentioned cup bottom part is connected, and the lower part of the undercut part is turned inward. The bent part is formed by bending 90 degrees or more. In this microwave oven paper cup, the gap width of the space between the bent portion and the bottom surface of the cup bottom member is 5 mm or less at the largest portion. A concave wedge may be provided on the above-mentioned bending portion.

According to the second paper cup for microwave ovens of the present invention, by bending the lower part of the undercut portion of the paper cup inwardly, it is possible to obtain a non-leakage of the contents when the contents such as beverages or instant foods are added to the paper cups and heated and cooked in a microwave oven. And no burnt paper cups for microwave ovens are produced in any part of the paper cups.

A third paper cup for microwave ovens according to the present invention has a cup body member that is rolled and formed into a cylindrical shape, and a cup bottom member that bends the outer peripheral edge to form a curved portion, so that the lower end of the cup body portion The folded folded part and the above-mentioned cup body clamp the above-mentioned curved part and combine to form a paper cup with an undercut part; the lower part of the above-mentioned undercut part is bent inward to form a bent part, and the bottom part of the cup The inner central portion of the bottom surface portion is provided with a convex-shaped portion facing inwardly in a convex shape. The gap width of the space between the said bending part and the said bottom part is 5 mm or less at the largest part.

In the third method of manufacturing paper cups for microwave ovens according to the present invention, a cylindrical cup body member is wound and formed, and the outer peripheral edge portion of the cup bottom member is bent to form a bent portion, and the cup body portion of the cup body member is formed into a curved portion. The folded part of the lower end part and the above-mentioned cup body sandwich the above-mentioned bent part and combine to form an undercut part, and the lower part of the above-mentioned undercut part is bent inward to form a bent part. The pressing part is provided with a vent hole, and the fixed mold part is made into a hollow cylindrical shape as a vent hole, so that a convex part protruding inwardly is formed in the inner central part of the bottom surface of the cup bottom member.

According to the third method of manufacturing paper cups for microwave ovens of the present invention, the bent portion is formed by bending the lower portion of the undercut portion inwardly, and a convex shape convex inwardly is provided on the inner central portion of the bottom portion. A paper cup for a microwave oven that does not leak the content and does not burn any part of the paper cup when the content such as beverages or instant food is added to the paper cup and heated and cooked in a microwave oven.

In the first microwave oven paper cup of the present invention, the cup body is formed by winding the cup body into a cylindrical shape, the upper end side of the cup body is bent to form an upper curling portion, and the outer circumference of the cup bottom member is The front end of the curved portion formed by bending the edge portion is disposed toward the lower end side of the cup body portion, and the folded portion folded by the lower end portion of the cup body portion and the cup body portion sandwich the curved portion to form an undercut portion, In this manner, the cup body member and the cup bottom member are joined to each other, and the lower portion of the undercut portion is folded inward on the thus formed paper cup. The bottom portion of the cup bottom member may be formed in a concave shape from the inner side to the lower side.

According to the first paper cup for microwave ovens of the present invention, the bottom folded portion formed by folding the undercut portion of the cup body member and the bottom member of the paper cup inwardly can reduce the height of the undercut portion, and, by folding the cup bottom The bottom part of the part is concaved downward, and when the content such as beverage or instant food is added to the paper cup and heated and cooked in a microwave oven, the microwave paper cup does not leak the content and does not cause scorching on any part of the paper cup.

The second paper cup for microwave ovens according to the present invention is composed of a cup body member formed by winding to form a cylindrical shape, and a cup bottom member formed by bending an outer peripheral edge portion to form a curved portion, and the cup body portion of the cup body member The joint portion is formed by joining with the bent portion, and the bottom curl portion is formed by rolling the joint portion inward in the paper cup formed in this way. In this microwave oven paper cup, the joining portion is joined so that a folded portion formed by folding a lower end portion of the cup body and the cup body sandwich the curved portion.

In the second method of manufacturing paper cups for microwave ovens according to the present invention, a cylindrical cup body member is formed by winding, the outer peripheral edge portion of the cup bottom member is bent to form a curved portion, and the cup body portion of the cup body member is The lower end part is combined with the above-mentioned curved part to form a joint part, and the above-mentioned joint part is rolled inward to form a bottom curling part, or a cylindrical cup member is formed by winding, and the outer peripheral edge part of the cup bottom part Folding to form a bent portion, so that the folded portion and the cup body sandwich the bent portion by folding the lower end portion of the cup body of the cup member, and combine to form a joint portion, and the The joint portion is rolled inward to form a bottom curl portion.

According to the second method of manufacturing paper cups for microwave ovens of the present invention, the bottom curling portion is formed by curling the joint portion of the cup body part and the cup bottom part of the paper cup inwardly, so that when adding beverages or instant foods, etc. A paper cup for a microwave oven that does not leak the contents and does not burn any part of the paper cup when the contents are heated and cooked in a microwave oven.

Description of drawings

Fig. 1 is a sectional view of a paper cup for a microwave oven according to a first embodiment of the present invention.

Fig. 2 is a sectional view of a paper cup for a microwave oven according to a second embodiment of the present invention.

Fig. 3 is a developed view of the semi-finished cup body part and cup bottom part of the paper cup for microwave oven according to the present invention.

Fig. 4 is a schematic diagram of the process of making the microwave oven paper cup of the present invention.

5 is a partial cross-sectional view showing a state in which a paper cup for a microwave oven is rolled up with a heat insulating case according to the first embodiment and the second embodiment of the present invention.

Fig. 6 is a partial cross-sectional view showing various examples of a cup body in a state where a heat-insulating casing is rolled up on a paper cup for a microwave oven according to the first embodiment of the present invention.

Fig. 7 is a cross-sectional view of a paper cup for a microwave oven according to a third embodiment of the present invention.

Fig. 8 is a cross-sectional view of another example of the microwave oven paper cup according to the third embodiment of the present invention.

Fig. 9 is a partial sectional view of an undercut portion of a paper cup for a microwave oven according to a third embodiment of the present invention.

Fig. 10 is a schematic diagram of a paper cup for a microwave oven according to a fourth embodiment of the present invention.

Fig. 11 is a cross-sectional view showing a state in which a paper cup for a microwave oven is rolled up with a heat insulating case according to a third embodiment of the present invention.

Fig. 12 is a partial cross-sectional view showing various examples of a cup body in a state where a heat-insulating casing is wound around a paper cup for a microwave oven according to a third embodiment of the present invention.

Fig. 13 is a partial sectional view showing a paper cup for a microwave oven according to a fifth embodiment of the present invention.

Fig. 14 is a partially enlarged cross-sectional view of a paper cup for a microwave oven according to a fifth embodiment of the present invention.

Fig. 15 is a partially enlarged cross-sectional view showing various examples of a bent portion of a paper cup for a microwave oven according to a fifth embodiment of the present invention.

Fig. 16 is a diagram showing a manufacturing process of a paper cup for a microwave oven according to a fifth embodiment of the present invention.

Fig. 17 is a partial sectional view showing a state in which a paper cup for a microwave oven is rolled up with a heat insulating case according to a fifth embodiment of the present invention.

Fig. 18 is a partial cross-sectional view showing various examples of a cup body in a state in which a paper cup for a microwave oven is wound with a heat insulating case according to a fifth embodiment of the present invention.

Fig. 19 is a partial sectional view of a paper cup for a microwave oven according to a sixth embodiment of the present invention.

Fig. 20 is a partial sectional view of a paper cup for a microwave oven according to a seventh embodiment of the present invention.

Fig. 21 is a partial cross-sectional view of an intermediate stage of a paper cup for a microwave oven according to a seventh embodiment of the present invention.

Fig. 22 is a diagram showing a manufacturing process of a paper cup for a microwave oven according to a sixth embodiment of the present invention.

Fig. 23 is a diagram showing a manufacturing process of a paper cup for a microwave oven according to a seventh embodiment of the present invention.

Fig. 24 is a cross-sectional view showing a state in which a paper cup for a microwave oven according to Embodiment 6 and Embodiment 7 of the present invention is wound with a heat insulating case.

Fig. 25 is a partial sectional view showing an example of a cup body in a state in which a paper cup for a microwave oven is wound with a heat insulating case according to a sixth embodiment of the present invention.

Fig. 26 is a partial sectional view of a paper cup for a microwave oven according to an eighth embodiment of the present invention.

Fig. 27 is a partial cross-sectional view of a paper cup as a semi-finished paper cup for a microwave oven according to an eighth embodiment of the present invention.

Fig. 28 is a partial sectional view of a paper cup for a microwave oven according to a ninth embodiment of the present invention.

Fig. 29 is a diagram showing the manufacturing process of paper cups for microwave ovens according to the eighth embodiment and the ninth embodiment of the present invention.

Fig. 30 is a cross-sectional view showing a state in which a paper cup for a microwave oven according to the eighth embodiment and the ninth embodiment of the present invention is wound with a heat insulating case.

Fig. 31 is a partial sectional view showing an example of a cup body in a state in which a paper cup for a microwave oven is wound with a heat insulating case according to an eighth embodiment of the present invention.

Fig. 32 is a partial sectional view of a conventional paper cup.

Fig. 33 is a partial sectional view of a conventional microwave oven paper cup.

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In a general paper cup a, as shown in FIG. 32 , the outer peripheral edge portion of the cup bottom member 2 is bent downward to form a bent portion 22 . The lower end portion of the cup member 1 is folded inward to form a folded portion 12 . The bent portion 22 is sandwiched between the folded portion 12 and the lower end portion of the cup portion 11 . The cup body 11 , the folded portion 12 and the bent portion 22 are bonded to each other by heat and pressure, thus forming the paper cup a. The joint portion of the cup body 11 , the folded portion 12 and the bent portion 22 is called an undercut portion 3 , and the bottom portion 21 of the cup bottom member 2 is lifted up by the undercut portion 3 to form a cup bottom. A part of the undercut portion 3 accumulates heat in the microwave oven, so that the undercut portion 3 is burnt.

[First and second embodiments]

Fig. 1 is a schematic diagram of a first embodiment of a paper cup for a microwave oven according to the present invention. A paper cup A for a microwave oven has a cup body 1 and a cup bottom 2, and is shaped according to a general paper cup a as shown in FIG. . The undercut part 3 of the paper cup a was folded inward as shown in FIG.

On paper cup A for microwave ovens, in order to prevent the force acting inwardly to return the undercut portion 3 to its original state from deteriorating the stability of the plane, the undercut portion 3 can be folded inward while the undercut portion 3 is folded inward. The inner surface of 3 is pasted on the outer surface of the bottom portion 21 of the cup bottom part 2 with adhesive or thermal bonding.

Fig. 2 is a second embodiment of the paper cup for microwave ovens of the present invention. The paper cup B for microwave ovens is formed according to the paper cup b in Fig. 2(a). In the paper cup b, the bottom portion 21 of the cup bottom member 2 of the paper cup a shown in FIG. 32 is concaved toward the inner surface side. The undercut portion 3 of the paper cup b is folded inward as shown in FIG. Since the bottom part 21 of the cup bottom part 2 is formed in a concave shape toward the inner side, the angle of the folded undercut part 3 is 90 degrees or more, which can reduce wrinkles when folded in, and enhance the stability of the paper cup B on the plane. .

Next, the manufacturing method of paper cup A, B for microwave ovens is demonstrated.

The paper cup a before the undercut portion 3 is folded inward is a general paper cup shape, and is formed by the cup body part semi-finished product 10 and the cup bottom part semi-finished product 20 shown in Figure 3, and is formed with a paper cup forming machine. Generally speaking, the semi-finished cup body part 10 uses the semi-finished product punched in the previous process in advance, and the semi-finished cup bottom part 20 is punched on the paper cup forming machine.

Next, the process of manufacturing the paper cup a using the semi-finished cup body member 10 and the semi-finished cup bottom member 20 will be briefly described. First, in order to bond the semi-finished cup body 10 into a cylindrical shape, the bonded parts 10a, 10b of the semi-finished cup body 10 are heated with hot air to melt the resin on the surface. Then, the cup body part semi-finished product 10 is rolled on the cup body mold (mandrel) and the bonding parts 10a, 10b are mutually laminated to form a cylindrical cup body part 1a (referring to Fig. 4 (a), (b )). In addition, the cup body member 1 a is a semi-finished product at a stage before forming the folded portion 12 and the bead portion 13 with respect to the cup body member 1 . On the other hand, the cup bottom member semi-finished product 20 is formed into a paper disk shape in which an outer peripheral edge is bent. The cup bottom member semi-finished product 20 formed into a paper plate shape is placed on a mandrel (not shown), and the cylindrical cup body member 1a is fitted on the mandrel. The resin of the joint portion (the portion forming the undercut portion) of the cylindrical cup body member 1a and the cup bottom member blank 20 is preheated with hot air. The lower end of the cylindrical cup member 1a is folded inward, and the outer peripheral edge of the cup bottom member semi-finished product 20 bent downward is sandwiched by the cup member 1a and its folded portion 12 . The clamped portion is press-fitted to form an undercut portion 3, whereby the cup body member 1a and the cup bottom member 2 are joined together. Furthermore, the upper end of the cylindrical cup member 1 a is curled outward to form an upper curled portion 13 . In this way, the forming of the paper cup a is completed.

When producing the paper cup B for a microwave oven in FIG. 2 , the bottom portion 21 of the cup bottom member 2 of the paper cup a is further formed into a concave shape inside the paper cup b. In the processing method of the bottom part 21, there exist the method of processing simultaneously in the shaping|molding process of the paper cup a, and the method of processing in the next process of a forming process. In the former method, the outer peripheral edge of the cup bottom semifinished product 20 is bent and the central part is also formed into a concave shape at the stage of forming the cup bottom semifinished product 20 into a paper disk shape and fitting it on the mandrel. In this way, the bottom surface portion 21 forming the cup bottom member 2 forms the paper cup b concaved inward. In the latter method, after the paper cup a is formed by a general method, the bottom portion 21 is formed inwardly concave by pressing.

When manufacturing the paper cups A and B for microwave ovens from the paper cups a and b, the undercut portion 3 of the paper cups a and b is folded inward. In this step, first, the undercut portion 3 is pressed down by more than 45 degrees inwardly by the method shown in FIG. 4( a ). Then, as shown in Fig. 4(b), use upper and lower thermal pressure or ultrasonic welding to compress the overwhelmed undercut portion 3 and melt the resin on the surface, and then solidify the resin to form a planar undercut. Part 3. At this time, the undercut portion 3 and the bottom portion 21 may be fixed with an adhesive or heat sealing. In addition, although the procedure of manufacturing paper cup A for a microwave oven from paper cup a is shown in FIG. 4, the procedure of manufacturing paper cup B for a microwave oven from paper cup b may be the same as this.

The paper cups A and B for microwave ovens are made of materials, basically paper is used as the main strength material, and the innermost layer has thermoplastic resin. For example, there are: paper layer/polyethylene resin layer, polyethylene resin layer/paper layer/polyethylene resin layer, foamed polyethylene resin layer/paper layer/polyethylene resin layer, polypropylene resin layer/paper layer/polypropylene Materials for paper cups for microwave ovens such as resin layers.

As the paper of the main strength material, it is best to use base paper with excellent formability for paper cups. There is no particular limitation on the weight per unit area, but it is preferably in the range of 150-300 g/m ² from the viewpoint of paper cup forming adaptability.

The thermoplastic resin used in the innermost layer must have the function of protecting the content, especially the filling of liquid substances without leakage. In addition, it must have the function of bonding the cup body with heat seal and combining the cup body with the bottom of the cup. . Specific examples include polyethylene, polypropylene, polyester, ethylene-vinyl acetate copolymer, and the like. The thickness of the resin layer is preferably in the range of 15 to 60 μm. The thermoplastic resin is formed in the innermost layer by injection molding or lamination.

When the paper cups A and B for microwave ovens with the above-mentioned structure are used in a microwave oven, it is difficult to hold them by hand because the contents are heated. Therefore, paper cups for microwave ovens with higher heat insulation properties are required. Therefore, in order to increase the heat insulation, it is also possible to wrap the heat-insulating cover 4 on the outer periphery of the paper cups A and B cups for microwave ovens to form a microwave oven as shown in Figure 5 (a) and Figure 5 (b). Use paper cups A', B'.

The shape of the heat insulating cover 4, as mentioned above, can also be the shape shown in Fig. 6 (a)～(d) except the shape pasted on the outer surface of the microwave oven paper cup A, B cup body portion 11. That is, as shown in Fig. 6 (a), the upper end portion of the cover body portion 41 of the heat insulating sleeve 4 is crimped inwardly to form the upper crimp portion 42a of the cup cover, or as shown in Fig. 6 (b), the insulator The upper end of the sleeve body portion 41 of the thermal sleeve 4 is folded inward to form an upper curved portion 42b of the cup sleeve. Also as shown in Figure 6(c), the lower end of the sleeve body 41 of the heat insulating sleeve 4 can be crimped inwardly to form the lower curling part 43a of the cup sleeve, or as shown in Figure 6(d), the sleeve The lower end of the body portion 41 is folded inside to form a lower curved portion 43b of the cup sleeve. Can be shown in Fig. 6 (a) or (b), in the upper end portion of the cover body portion 41 of heat-insulating cover 4, form the upper curling part 42a of cup cover or the upper bending part 42b of cup cover, also can be shown in Fig. 6 (c ) or (d), the lower end of the sleeve body 41 is formed with a lower curling portion 43a or a lower curved portion 43b of the cup. Fig. 6 shows an example of a paper cup A' for a microwave oven, but the same shape may be used for the heat insulating cover 4 of a paper cup B' for a microwave oven. According to the above-mentioned shape, since the diameter corresponding to the upper curling portion 42a of the cup sleeve or the lower curling portion 43a of the cup sleeve, or the upper curved portion 42b of the cup sleeve or the lower portion of the cup sleeve is formed between the cup body portion 11 and the heat insulating sleeve 4 The curved portion 43b has gaps 5 at intervals in thickness, so heat insulation can be ensured over the entire length of the microwave oven paper cups A', B' in the vertical direction.

The heat insulating cover 4 is attached to the outer periphery of the cup body 11 , but it is not necessary to cover the entire periphery of the cup body 11 . The heat insulating cover 4 is formed to be shorter than the vertical length of the cup body 11 , for example, the heat insulating cover 4 may be limited to the upper portion of the outer surface of the cup body 11 .

The material used for the heat insulating cover 4 is a heat insulating material, for example, cardboard, single-sided corrugated cardboard, corrugated cardboard, embossed paper, foamed paper, etc. can be used.

The cardboard mainly used is mainly coated cardboard, Manila cardboard, thick glossy cardboard and other cardboard with a smooth surface, and the thickness is preferably in the range of 200-400g/ ^m2 .

There are types of corrugated cardboard, such as A corrugated, B corrugated, E corrugated, F corrugated, etc., but from the viewpoint of being wound on the paper cup body (cup body part 11), it is best to use F or E corrugated cardboard with flexibility. . In addition, it is possible to use single-sided corrugated cardboard without a backing paper on one side, or to use corrugated core paper that protrudes outward. In addition, corrugated cardboard corrugated on a corrugated mold can also be used.

Embossed paper is different from ordinary corrugated board paper. It is corrugated in dots and grids with a depth of 1 to 2 mm on the core paper and bonded to the backing paper. The backing paper can be laminated on one or both sides. The range of the core paper may be 100-180g/m ² , and the range of the backing paper may be 200-270g/m ² . In addition, like corrugated cardboard, it has a thermal insulation effect, and patterns can be printed on the lining paper on the surface to improve its aesthetics.

The composition of foamed processed paper is basically a structure of foamed thermoplastic resin layer/paper layer/thermoplastic resin layer. Specifically, a laminate composed of a foamed low-density polyethylene resin layer/coated paper/a mixed resin layer of low-density polyethylene resin and high-density polyethylene resin is used. When wound around the cup body 11 of the paper cups A' and B' for microwave ovens, a foamed resin layer may be used as the surface, or a non-foamed resin layer may be used as the surface.

[Third and Fourth Embodiments]

Fig. 7 is a schematic diagram of a third embodiment of a paper cup for a microwave oven according to the present invention. On the microwave oven paper cup C of FIG. 7, the lower part of the undercut portion 3 of the paper cup a as shown in FIG. A space O is provided between the bent portion 3 a and the bottom surface portion 21 of the cup bottom member 2 . The portion where the bending portion 3a is bent is set within a range from 1/2 to 3/4 of the full width Ha of the undercut portion 3 from the lower end of the undercut portion 3 . The gap width of the space O between the bent portion 3a and the bottom surface portion 21 of the cup bottom member 2 is preferably not more than 5 mm, and more preferably not more than 2 mm. When exceeding 5mm, there is a possibility of scorching. The bending angle can be set within a range from 90 degrees shown in FIG. The greater the angle at which the bending portion 3a is bent, the greater the effect of suppressing the occurrence of wrinkles.

The microwave oven paper cup C of Fig. 7, as shown in Fig. 8 (a), also can be based on the folded portion 12 of the cup body member 1 as the inner surface of the undercut portion 3, limited in advance from the lower end to the undercut portion 3 The paper cup c of the width of the position P where the lower part is bent is made. When making a paper cup C for a microwave oven from a paper cup c, as shown in FIG. 3Bend to this position P.

On the paper cup C for microwave ovens, in order to prevent the effect of the restoring force of the undercut part 3 bent inwardly from deteriorating the stability on the plane, the lower part of the undercut part 3 can be bent inwardly, and the The front end portion of the bent portion 3 a is joined to and fixed to the outer surface of the bottom surface portion 21 of the cup bottom member 2 .

As the shape of the bending portion 3a of the paper cup C for microwave ovens, in addition to the above-mentioned linear shape, it can also be a shape bent into an arc as shown in Figure 9 (a), or a shape that is bent into an arc as shown in Figure 9 (b). The front end of the linear bending portion 3a is bent into a shape at right angles to the bottom surface 21 side, as shown in FIG. 9 (d), (e), (f) and (g) as shown in Figure 9 (d), (e), (f) and (g) may be the shape of the front end portion of the bending portion 3a to support the bottom portion 21.

Fig. 10 is a schematic diagram of a fourth embodiment of a paper cup for a microwave oven according to the present invention. In the microwave oven paper cup D of the fourth embodiment, as shown in FIG. The lower portion of the undercut portion 3 serves as a bent portion 3a bent inward at an angle of approximately 90 degrees. This point is the same as the microwave oven paper cup C of FIG. 7 . Instead of the paper cup a, the paper cup D for microwave ovens can also be manufactured based on the paper cup c of FIG. 8( a ). Furthermore, in the paper cup D for a microwave oven, a predetermined number of concave wedges Q (in the illustrated example, four places) are provided on the bent portion 3a. As shown in the schematic cross-sectional view of FIG. 10( b ), the wedge Q is formed in a concave shape that becomes deeper toward the tip of the bent portion 3 a. When the wedge Q is not provided, a plurality of wrinkles R are formed on the bent portion 3a as shown in FIG. 10(c). On the other hand, when the wedge Q is provided, the crease R generated when the bending portion 3a is bent is absorbed by the portion of the wedge Q, and the generation of the crease R can be suppressed. Therefore, the appearance is better, and the paper cup for microwave ovens has better stability on the D plane. The number of wedges Q is sufficient as long as the crease R cannot be seen at the bent portion 3a. Preferably, 4 to 8 wedges Q are provided at equal intervals in the circumferential direction of the bending portion 3a.

Next, the manufacturing methods of paper cups C and D for microwave ovens will be described.

Even when making paper cups C and D for microwave ovens, the paper cup a before the undercut portion 3 is bent inwardly is also the shape of a general paper cup. , Shaped with a paper cup forming machine. The procedure for manufacturing the paper cup a from the semi-finished products 10 and 20 is the same as that of the paper cups A and B for microwave ovens described above, and the description thereof will be omitted here.

When manufacturing the paper cup C for a microwave oven from the paper cup a, the lower part of the undercut part 3 of the paper cup a is bent inward. This processing can be performed according to the method shown in Fig. 4(a) and (b).

Moreover, when manufacturing the paper cup D for microwave ovens of FIG. 10, the wedge Q is provided in several places of the folded part 3a. This processing can be performed by pressing a die provided with a raised portion T as shown in FIG. 4( c ) instead of the upper die during hot press processing as shown in FIG. 4( b ).

The materials used in paper cups C and D for microwave ovens are basically made of paper as the main strength material, and there is a thermoplastic resin on the innermost layer. Specific examples of materials are the same.

In order to add heat insulation to the above paper cups C and D for microwave ovens, as shown in Figure 11, a heat insulating cover 4 can also be wound on the outer peripheral surface of the cup body 11 to form paper cups C' and D' for microwave ovens. .

The shape of the heat insulation cover 4, in addition to the shape pasted and installed on the outer peripheral surface of the cup body portion 11 of the above-mentioned microwave oven paper cup C, D, also can be shown in Figure 12 (a)～(d) alone or in combination. The curled portion 42a, 43a, or the shape of the bent portion 42b, 43b. The specific shapes in Fig. 12(a) to (d) are the same as those shown in Fig. 6, so detailed description thereof will be omitted. 12 shows an example of a paper cup C' for a microwave oven, but the heat insulating cover 4 of a paper cup D' for a microwave oven may have the same shape. According to the above shape, between the cup body portion 11 and the sleeve body portion 41 of the heat insulating sleeve 4, due to the formation of a diameter corresponding to the upper curling portion 42a of the sleeve body or the lower curling portion 43a of the sleeve body, or the sleeve body The gap 5 between the thickness of the upper curved portion 42b or the lower curved portion 43b of the casing can ensure the heat insulation of the entire length of the microwave oven paper cups C', D' in the vertical direction.

In the microwave oven paper cups C', D', the heat insulating cover 4 can also be made shorter than the length of the cup body 11 in the vertical direction, and installed on the upper part of the outer surface of the cup body 11. Among the materials used for the heat insulating jacket 4 , the same materials as those of the heat insulating jacket 4 shown in FIGS. 5 and 6 can be used.

[fifth embodiment]

Fig. 13 is a schematic diagram of a fifth embodiment of a paper cup for a microwave oven according to the present invention. The paper cup E for a microwave oven according to the fifth embodiment has a body member 1 and a cup bottom member 2 as well as a general paper cup, and also has an undercut portion 3 as a joining portion of the cup body member 1 and the cup bottom member 2 . The lower portion of the undercut portion 3 is bent inwardly to form a bent portion 3 a, so that the microwave oven paper cup E is formed into a shape having a space O between the bottom surface 21 of the cup bottom member 2 .

The position where the bending portion 3a is bent, that is, the width h of the bending portion 3a, as shown in the partial enlarged view of FIG. /4 range. As shown in FIG. 14(b), the gap width o between the bent portion 3a and the bottom surface portion 21 of the cup bottom member 2 is preferably 5 mm or less at its maximum, and more preferably 3 mm or less. When exceeding 5mm, there is a possibility of scorching.

The angle at which the bending portion 3a is bent is not particularly limited, but is preferably approximately 90 degrees.

The shape of the bending portion 3a is a bent arc shape as shown in FIG. 14(b), or a straight line shape as shown in FIG. 15 . The front end portion of the linear bending portion 3a shown in FIG. 15(b) can be folded into a right-angled shape toward the bottom surface 21 side, or the front end portion of the bending portion 3a shown in FIG. 15(c) can be folded toward the bottom surface. The portion 21 is side-folded into an arc shape. As shown in FIGS. 15( d ), ( e ), ( f ), and ( g ), it may be a shape in which the bottom surface portion 21 is supported by the front end portion of the bending portion 3 a.

As shown in FIG. 13, in the paper cup E for microwave ovens, the center part inside the bottom surface part 21 is provided with the circular convex-shaped part 21a convex toward inward. When the convex portion 21a is provided at the central portion of the bottom portion 21, when the contents are added to the microwave oven paper cup E and used in the microwave oven, on the bottom portion 21, the convex portion facing the inside of the microwave oven paper cup E Conversely, the shape of the convex portion 21a becomes convex in the outward direction, which has the effect of reducing the burning of the undercut portion 3 of the paper cup E for microwave ovens. The convex portion 21a is formed in an arc shape. The shape of the convex portion 21a is not limited, but its maximum height d is preferably 0.2 mm or more.

Next, the manufacturing method of the paper cup E for microwave ovens is demonstrated.

The paper cup a before the lower portion of the undercut portion 3 is bent inward to form the bent portion 3a can be produced in the same manner as the paper cup A for a microwave oven described above.

Then, when manufacturing the paper cup E for a microwave oven, the lower portion of the undercut portion 3 of the paper cup a is bent inward to form the bent portion 3a. This process is performed in the following order. First, by the method shown in FIG. 16(a), the lower portion of the undercut portion 3 is pressed inwardly by more than 30 degrees. Then, by the method shown in Fig. 16(b), (c), the crushed bent portion 3a is pressed from top to bottom by heat pressing or ultrasonic welding to form an arc shape. At this time, as shown in Fig. 16(d), instead of providing an air vent on the pressing portion 51 of the stamping die 50, the fixed mold 52 is made into a hollow cylindrical shape to be an air vent so that the internal pressure increases while A circular convex portion 21 a projecting inward is formed at the inner central portion of the bottom surface portion 21 of the cup bottom member 2 . By providing the convex portion 21a on the inner central portion of the bottom portion 21, when the content is added to the paper cup E for a microwave oven and used in a microwave oven, the convex portion 21a on the bottom portion 21 and toward the inside of the paper cup E for a microwave oven Conversely, the shape of the convex portion 21a is convex toward the outside, which has the effect of reducing the burning of the undercut portion 3 of the paper cup E for microwave ovens.

Next, the composition of the material used in the microwave oven paper cup E is basically paper as the main strength material, and there is a thermoplastic resin on the innermost layer. The specific structure of the material can be explained with the material of the first microwave oven paper cup A above. The same as the specific example.

In order to increase the heat insulation of the microwave oven paper cup E, the heat insulating sleeve 4 can also be wrapped around the outer periphery of the cup body 11 of the microwave oven paper cup E to form the microwave oven paper cup E' shown in FIG. 17 .

The shape of the heat insulating cover 4 may be the shape of the curled parts 42a, 43a or the bent parts 42b, 43b shown in Fig. 18(a) to (d) alone or in combination. The details of the shapes in Fig. 18(a) to (d) are the same as those in Fig. 6 and Fig. 12, so detailed description thereof will be omitted. The heat insulating cover 4 is shorter than the length of the cup body 11 in the vertical direction, and can be attached to the upper portion of the outer surface of the cup body 11 . The material of the heat insulation cover 4 on the paper cup E' for microwave ovens can also be the same as that of Fig. 6 and Fig. 12 .

[Sixth and seventh embodiments]

Fig. 19 is a schematic diagram of a paper cup for a microwave oven according to a sixth embodiment of the present invention. Microwave oven paper cup F is a structure in which the lower half of the undercut portion 3 of a general paper cup a as shown in FIG.

Fig. 20 is a schematic view of a paper cup for a microwave oven according to a seventh embodiment of the present invention. In the paper cup G for a microwave oven, the bottom surface 21 of the cup bottom member 2 of the paper cup F for a microwave oven shown in FIG.

As shown in FIG. 20( b ), this bottom surface portion 21U has a U-shape deformed downward in a concave shape when viewed from the inside. In addition, the bottom surface portion 21U has a lower surface portion 21Ua and a wall surface portion 21Ub as shown in FIG. 20( c ). A curved portion R is formed between the lower surface portion 21Ua and the wall portion 21Ub. It is preferable to form the lower surface portion 21Ua into a planar shape and place the wall portion 21Ub in the vicinity of the bottom folded portion 3a. The radius of curvature of the curved portion R is preferably in the range of 3 to 10 mm, more preferably in the range of 5 to 8 mm. When the radius of curvature is less than 3 mm, blisters occur, which cause leakage. On the other hand, when the radius of curvature exceeds 10 mm, burning tends to occur at the undercut portion 3 .

The maximum depth d of the bottom portion 21U is preferably greater than 50% of the width (height) of the undercut portion 3 from the upper end of the undercut portion 3 in the folded state. If it exceeds 50%, the irradiation of microwaves to the back side of the undercut portion 3 can be blocked in the microwave oven, and burning of the undercut portion 3 can be prevented. If it is less than 50%, there is a danger of scorching the undercut portion 3 .

The distance x between the lower surface portion 21Ua and the lower end surface X formed by the lower end of the cup body portion 11 is preferably within a range of less than 5 mm when upward and less than 2 mm when downward. When the distance x is 5 mm or more upward as shown in FIG. 21( a ), there is no effect of shielding microwaves to the back side of the undercut portion 3 . When the distance x is 2 mm or more downward as shown in FIG. 21( b ), the paper cup G for microwave ovens may lose stability.

In addition, in the sixth embodiment, when the height of the undercut portion 3 is within 10 mm, the height of the undercut portion 3 can be effectively reduced to 5 mm or less by folding the lower portion of the undercut portion 3 inward. Therefore, when the height of the undercut portion 3 exceeds 10 mm, and even after the lower part of the undercut portion 3 is folded inwardly, the height of the undercut portion 3 exceeds 5 mm, it is preferable to use the bottom portion 21 of the cup bottom member 2 The structure of the seventh embodiment deformed downward into a concave shape.

Next, the manufacturing method of the paper cups F and G for microwave ovens is demonstrated.

When manufacturing the paper cup F for a microwave oven according to the sixth embodiment, first, the paper cup a of FIG. 32 is manufactured. The manufacturing sequence may be the same as that of the above-mentioned paper cup A for microwave ovens.

When the lower portion of the undercut portion 3 of the paper cup a is bent inwardly to form the bent portion 3a, the lower portion of the undercut portion 3 is pressed inwardly by more than 45 degrees as shown in FIG. 22 (a). Then, by the method shown in FIG. 22(b), the overwhelmed part is pressed down by upper and lower punching, whereby the undercut portion 3 is folded into a folded shape with the bottom folded portion 3a. Also, by the method shown in FIG. 22(c), the folded undercut portion 3 can be formed by pressing from the surface side and using the bottom folded portion 3a.

In this way, the lower portion of the undercut portion 3 of the paper cup a is folded inward to form the bottom folded portion 3a, and the microwave oven paper cup F of the sixth embodiment can be manufactured.

When manufacturing the paper cup G for microwave ovens which concerns on 7th Embodiment, the said paper cup F for microwave ovens which deform|transformed the bottom part 21 of the cup bottom part 2 into a concave shape is manufactured.

Then, by lifting the bottom, the planar bottom portion 21 is deformed into a concave shape and a U-shape. The process of deforming the bottom portion 21 into a concave shape, as shown in FIG. 23(a), is carried out with a punch 102 having a concave portion 102a on the lower surface after the paper cup is fitted on a mandrel 101 having a convex portion 101a on the upper surface. Deformation, the bottom portion 21 is deformed into a U-shape. For easy processing and forming, methods of preheating the cup bottom member 2, heating the punch 102, or ultrasonically vibrating the punch 102 can be used. As shown in FIG. 23(b), it is also possible to use a method of pressing the rotating roller 103 while rotating the mandrel 101.

The composition of the materials used in the paper cups for microwave ovens is basically paper as the main strength material, and the innermost layer has thermoplastic resin.

In order to increase heat insulation, it is also possible to cover microwave oven paper cups F and G, as shown in Figure 24 (a) and (b), put a heat insulating cover 4 on the outer circumference of the cup body 11 to form microwave oven paper cups F', G'.

The shape of the heat insulating sleeve 4, in addition to the shape tightly installed on the outside of the cup body 11, can also be the curling parts 42a, 43a or the bending parts 42b, 43b shown in Figure 25 (a) to (d) alone or in combination. shape. 25(a) to (d) are the same as those in FIG. 6 and FIG. 12, so detailed description thereof will be omitted. Fig. 25 shows an example of a paper cup F' for a microwave oven, but the heat insulating cover 4 of a paper cup G' for a microwave oven can also be formed in the same shape. The heat insulating cover 4 is shorter than the vertical length of the cup body 11 of the paper cups F′ and G′ for microwave ovens, and can be attached to the upper portion of the outer surface of the cup body 11 . The material of the insulation sleeve 4 on the paper cups F', G' for microwave ovens can also be the same as that shown in Fig. 6 and Fig. 12 .

[Eighth and ninth embodiments]

Fig. 26 is a schematic diagram of a paper cup for a microwave oven according to an eighth embodiment of the present invention. The paper cup H for microwave ovens is made according to the paper cup e shown in FIG. 27 . The paper cup e has a cup body member 1 and a cup bottom member 2 . The outer peripheral edge portion of the cup bottom member 2 is bent downward to form a bent portion 22, and the bent portion 22 and the lower end portion of the cup body 11 of the cup body member 1 are thermocompression-bonded to form a bonding portion 3'. Paper cups H for microwave ovens were produced by curling the joint portion 3' of the paper cup e inwardly to form the cup bottom bead portion 3b. The height h of the bead portion 3b of the cup bottom is preferably 1/2 or less of the height Ha of the joint portion 3 before curling.

Fig. 28 is a schematic view of a paper cup for a microwave oven according to a ninth embodiment of the present invention. In the paper cup 1 for microwave ovens, the undercut portion 3 of the general paper cup a shown in FIG. 32 is curled inward to form a bottom curl portion 3c. The height h of the bottom curling portion 3c is 1/2 or less of the height Ha of the curling front undercut portion 3 .

Next, the manufacturing method of paper cup H, I for microwave ovens is demonstrated.

The paper cup e before the joint part 3' is curled inward and the paper cup a before the undercut part 3 is curled inward are formed by the semi-finished cup body part 10 and the cup bottom part semi-finished product 20 shown in Figure 3 with a paper cup forming machine. of. The manufacturing sequence of the paper cup a is as above. The manufacturing procedure of the paper cup e is different from that of the paper cup a in that the lower end of the cylindrical cup body part 1a and the underside of the semi-finished cup bottom part 20 are pressed against the bent outer peripheral edge to form a joint 3'. Combining the cup body part 1 and the cup bottom part 2.

Then, the joint portion 3' of the paper cup e is curled inwardly to form the bottom curling portion 3b to manufacture the paper cup H for microwave ovens. In addition, the undercut portion 3 of the paper cup a is curled inward to form the bottom curling portion 3c. Paper cup I for microwave ovens can be manufactured.

In this manufacturing process, first, the bonding portion 3' or the undercut portion 3 is rolled inward in an arc shape by the method shown in Fig. 29(a). Then, by the method shown in FIG. 29(b), it is deformed by curling inwardly with a concave mold from above. This can form the bottom bead portion 3b or the bottom bead portion 3c. In addition, although FIG. 29 is an example diagram of manufacturing the paper cup H for a microwave oven, the procedure is the same when manufacturing the paper cup I for a microwave oven.

The materials used in paper cups H and I for microwave ovens are basically made of paper as the main strength material, and there is thermoplastic resin on the innermost layer. .

On paper cups H and I for microwave ovens, in order to increase heat insulation, as shown in Figure 30 (a), (b), it is also possible to form paper cups for microwave ovens in the state of wrapping heat insulating sleeve 4 on the outer periphery of cup body 11. H', I'.

As the shape of the heat-insulating cover 4, as mentioned above, in addition to the shape closely combined on the outer surface of the paper cup A and B cup body 11 for microwave ovens, it can also be shown in Figure 31 (a)-(d) alone or in combination. The shape of the curled portion 42a, 43a or the bent portion 42b, 43b. The shapes of Fig. 31 (a) to (d) are the same as those in Fig. 6, Fig. 12, Fig. 18 and Fig. 25 in detail. Fig. 31 is an example of a paper cup H' for a microwave oven, but the paper cup I' for a microwave oven also has the same shape. The insulation cover 4 is shorter than the length of the cup body portion 11 of the microwave oven paper cup H′, I′ in the up and down direction, and can be installed on the top of the cup body portion 11 outside. The heat insulation cover 4 material of microwave oven paper cup H', I' is also the same as Fig. 6, Fig. 12, Fig. 18 and Fig. 25.

The paper cup for microwave ovens of the present invention, or the paper cup for microwave ovens, can be used as containers for heating instant foods such as instant noodles and as containers for hot beverages such as coffee, black tea, and soup.

Example

Next, the embodiment of the paper cup for microwave ovens of this invention is demonstrated more concretely.

[Example 1-1]

As Example 1-1 of the paper cup for a microwave oven of the present invention, the paper cup A for a microwave oven shown in FIG. 1 was produced. For the cup body member 1, a material composed of cup base paper 280 g/m ² /low-density polyethylene resin 25 μm is used from the surface. The cup bottom member 2 is made of cup base paper 255g/m ² /low-density polyethylene resin 25μm from the surface. In the punching process, a cup member semi-finished product 10 shown in FIG. 3 is produced, and the cup body member semi-finished product 10 is wound around a mandrel to form a cylindrical cup body member 1a. Then, with a general paper cup forming machine, insert the cup bottom part semi-finished product 20 from below the cup body part 1a, heat the joint part with hot air, and fold the lower end of the cup body part 1a inwardly as the folded part 12 and make a paper cup a. Subsequently, with the method shown in Figure 4 (a), the undercut portion 3 is folded inward, and processed by hot pressing shown in Figure 4 (b) (processing conditions: the temperature is 120°C, the pressure is 600KPa, and the time is 5 seconds), the undercut portion 3 is compressed and deformed, the resin in the joint portion of the undercut portion 3 is melted and solidified, and the undercut portion 3 is formed into a planar shape to make a microwave oven paper cup A.

On the paper cup A for microwave ovens in Example 1-1, the undercut portion 3 of the paper cup a is folded inward, so that when the content is loaded and heated and cooked in a microwave oven, the undercut portion 3 will not be burnt .

[Example 1-2]

As Example 1-2 of the paper cup for a microwave oven of the present invention, the paper cup B for a microwave oven shown in FIG. 2( b ) was produced. First, paper cup a was produced in the same manner as in Example 1-1. Then, the bottom surface portion 21 of the cup bottom member 2 of the produced paper cup a is deformed into a concave shape inward to produce a paper cup b. Then, the undercut portion 3 is folded inward, and the undercut portion 3 is bonded and fixed to the bottom surface portion 21 of the cup bottom member 2 with an adhesive, thereby producing a paper cup B for a microwave oven.

On the paper cup B for microwave ovens of this embodiment 1-2, the undercut part 3 of the paper cup b is folded inward, so that when the content is loaded and heated and cooked in a microwave oven, no burning will occur at the undercut part 3. coke. In addition, by deforming the bottom portion 21 of the cup bottom member 2 of the paper cup b inwardly into a concave shape, the angle at which the undercut portion 3 is folded in is 90 degrees or more, so that wrinkles generated during folding can be absorbed and reduced. Make the stability of the paper cup B on the plane better.

[Example 1-3]

As Examples 1-3 of the paper cup for a microwave oven of the present invention, a paper cup A' for a microwave oven shown in Fig. 5(a) was produced. Make and use the heat insulating cover 4 of the outer whole tubular corrugated cardboard (F corrugated) of the cup body part 11 corresponding to the paper cup A for microwave oven of embodiment 1-2, and insert in this tubular heat insulating cover 4 Paper cup A for microwave ovens was partially bonded and fixed to produce paper cups for microwave ovens A' as shown in Fig. 5(a).

On the paper cup A' for microwave ovens of Examples 1-3, the undercut part 3 of the paper cup b is folded inward, so that when the content is loaded and cooked in a microwave oven, no burning will occur at the undercut part 3. coke. In addition, by installing the heat insulation cover 4 made of corrugated cardboard on the cup body 11, it has heat insulation and the heated content is not easy to become cold. In addition, it is difficult to feel the heat of the content, and it can be used Touch and pick up the Microwave Cup A'.

[Example 2-1]

As Example 2-1 of the paper cup for a microwave oven of the present invention, the paper cup C for a microwave oven shown in FIG. 7( b ) was produced. On the cup body part 1, a material composed of cup base paper 280g/m ² /low density polyethylene resin 25μm is used from the surface, and on the cup bottom part 2, a cup base paper 255g/m is used from the surface ² /Material composed of low density polyethylene resin 25μm. Paper cup a, which is a semi-finished product of paper cup C for microwave ovens, was produced in the same procedure as in Example 1-1 above. The lower portion of the undercut portion 3 of the paper cup a is bent inwardly to a position where the front end portion of the bent portion 3a contacts the bottom portion 21 of the cup bottom member 2, and an adhesive is applied. The front end portion of the bent portion 3a is bonded and fixed to the bottom portion 21 to obtain a paper cup C for a microwave oven.

On the paper cup C for microwave ovens of this embodiment 2-1, by bending the lower part of the undercut portion 3 of the paper cup a inwardly, it is possible to keep the undercut portion 3 out of the way when the content is loaded and heated and cooked in a microwave oven. Burning will occur.

[Example 2-2]

As Example 2-2 of the paper cup for a microwave oven of the present invention, a paper cup D for a microwave oven shown in FIG. 10 was produced. The paper cup a was produced in the same procedure as in Example 2-1, and then the lower part of the undercut portion 3 of the paper cup a was bent inward by about 90 degrees. On the bent bent portion 3a, four concave wedges Q are provided at equal intervals along the circumferential direction of the undercut portion 3 to form a paper cup D for a microwave oven.

On the paper cup D for a microwave oven of this embodiment 2-2, by bending the undercut part 3 of the paper cup a inwardly, when the content is loaded and heated and cooked in a microwave oven, there will be no damage to the undercut part 3. burnt. In addition, since four recessed wedges Q are provided at equal intervals on the bending portion 3a, wrinkles generated at the time of folding can be absorbed, and the stability on the plane is improved.

[Example 2-3]

As Example 2-3 of the microwave oven paper cup of the present invention, a microwave oven paper cup C' shown in Fig. 11(b) was produced. Make and use the heat-insulating cover 4 of tubular corrugated cardboard (F corrugated) that corresponds to the outer surface of the cup body portion 11 of the paper cup C for microwave oven C of Example 2-2 as a whole, and insert it in the cylindrical heat-insulating cover 4 The paper cup C for a microwave oven was locally bonded and fixed to produce a paper cup C' for a microwave oven as shown in FIG. 11 .

On the paper cup C' for microwave ovens of this embodiment 2-3, by bending the lower part of the undercut part 3 of the paper cup a inwardly, it is possible to keep the undercut part 3 under the condition of the undercut part 3 when the content is loaded and heated and cooked in a microwave oven. No scorching occurs. In addition, the heat insulation cover 4 made of corrugated cardboard is installed on the cup body 11, so it has heat insulation, and the heated content is not easy to become cold, and it is difficult to feel the heat of the content, so it can be touched by hand. And pick up the microwaveable paper cup C'.

[Example 3-1]

As Example 3-1 of the paper cup for a microwave oven of the present invention, a paper cup E for a microwave oven shown in FIG. 13 was produced. For the cup body part 1, a material composed of cup base paper 280g/m ² /low density polyethylene resin 25μm is used from the surface, and for the cup bottom part 2, a base paper 255g/m ² is used from the surface / Low-density polyethylene resin 25μm material. Paper cup a, which is a semi-finished paper cup E for microwave ovens, was produced in the same procedure as in Example 1-1 above. The lower portion of the undercut portion 3 of the paper cup a is bent inwardly to form an outwardly bulging arc-shaped bent portion 3a, and a hollow cylinder is used on the fixed die 52 of the stamping die 50 of FIG. 16 . The shape of the mold, and in the bottom part 21 inside the central part is provided with a convex circular convex part 21a toward the inside, thus made a microwave oven paper cup E.

On the microwave oven paper cup E of this embodiment, the lower portion of the undercut portion 3 of the paper cup a is bent inward into an arc shape, and a convex circular shape facing inward is provided on the inner central portion of the bottom surface portion 21. part 21a, in this way, when the content is added to the microwave oven paper cup E and used in the microwave oven, the shape of the convex part 21a that is convex toward the inside on the bottom part 21 is reversed into a convex shape toward the outside, greatly reducing the There is a danger of scorching at the undercut portion of the paper cup E for microwave ovens, but no scorching will occur at the undercut portion 3 when the contents are loaded and heated and cooked in a microwave oven.

Microwave oven paper cup E of the present invention using at least a part of the lower part of the undercut part as a curved part that is bent inward in an arc shape, and a convex part that is convex inward and circular at the center part inside the bottom part. , and loaded into various contents, and actually used and evaluated in a microwave oven, the results are summarized in Table 1.

Evaluation method: Add 200ml of water into the paper cup and confirm the change of the paper cup.

○: No discoloration or burnt

□: Discoloration

×: burnt

Table 1

Evaluation with household microwave oven (NE company -500W) bending part Convex Heating time (minutes) 1 3 6 10 15 none none ○ △ x x x have none ○ ○ ○ ○ x have have ○ ○ ○ ○ ○

Evaluation with household microwave oven (HI company -500W) bending part Convex Heating time (minutes) 1 3 6 10 15 none none ○ ○ △ x x have none ○ ○ ○ ○ ○ have have ○ ○ ○ ○ ○

Evaluation with household microwave oven (TO company -500W) bending part Convex Heating time (minutes) 1 3 6 10 15 none none ○ ○ ○ △ △ have none ○ ○ ○ ○ ○ have have ○ ○ ○ ○ ○

Evaluation with household microwave oven (TO company -570W) bending part Convex Heating time (minutes) 1 3 6 10 15 none none ○ ○ x x x have none ○ ○ ○ ○ △ have have ○ ○ ○ ○ ○

[Example 4-1]

As Example 4-1 of the paper cup for a microwave oven according to the present invention, a paper cup F for a microwave oven shown in FIG. 19 was produced. On the cup body part 1, a material composed of cup base paper 280g/m ² /low density polyethylene resin 25μm is used from the surface, and on the cup bottom part 2, a cup base paper 255g/m is used from the surface ² /Material composed of low density polyethylene resin 25μm. Paper cup a, which is a semi-finished product of paper cup F for microwave ovens, was produced in the same procedure as in Example 1-1 above. The undercut portion 3 of the paper cup a had a height of 10 mm. Using the process shown in FIG. 22, the lower half of the undercut portion 3 is folded inward to form the bottom folded portion 3a, and a paper cup F for microwave ovens with a height of undercut portion 3 of 5 mm is obtained.

On the paper cup E for microwave ovens of this Example 4-1, by bending the undercut portion 3 of the paper cup a inwardly, when the content is loaded and heated and cooked in a microwave oven, no cracking is found in any part of the paper cup. burnt. Moreover, it has good stability on a plane.

[Example 4-2]

As Example 4-2 of the paper cup for a microwave oven of the present invention, the paper cup G for a microwave oven shown in FIG. 20 was produced. First, as described in Embodiment 4-1, at first, the lower half of the undercut portion 3 with a height of 15 mm is folded to form the folded portion 3 a, and the height of the undercut portion 3 is 7 mm, as shown in FIG. 19 . Microwave oven paper cup F shown. Then, with the process shown in FIG. 23, the bottom portion 21 of the cup bottom member 2 of the microwave oven paper cup F is deformed downward into a concave shape, and a microwave oven paper cup G with a U-shaped bottom portion 21U having a depth of 5 mm is produced.

In the paper cup G for a microwave oven of Example 4-2, when the contents were loaded and cooked in a microwave oven, scorching was not observed in any part of the paper cup. Moreover, it has good stability on a plane.

[Example 4-3]

As Example 4-3 of the microwave oven paper cup of the present invention, a microwave oven paper cup F' shown in Fig. 24(a) was produced. A heat insulating cover 4 using a tubular corrugated cardboard (F corrugated) corresponding to the entire outer surface of the cup body part 11 of the microwave oven paper cup F of Example 4-1 was made, and embedded in the cylindrical heat insulating cover 4. paper cup F for microwave ovens, and partially bonded and fixed to produce paper cups F' for microwave ovens.

In the paper cup F' for microwave oven of Example 4-3, since the undercut portion 3 of the paper cup a was folded inward, no scorching occurred in any part of the paper cup when the content was loaded and heated and cooked in a microwave oven. And, on the cup body part 11, install the heat-insulating cover 4 with corrugated cardboard as heat-insulating material, thereby have heat-insulating property, and the content that has been heated is not easy to become cold, in addition, it is difficult to feel the heat of content, can use Touch and pick up the microwave oven paper cup F'.

[Example 4-4]

As Example 4-4 of the microwave oven paper cup of the present invention, a microwave oven paper cup G' shown in Fig. 24(b) was produced. A heat insulating cover 4 using a tubular corrugated cardboard (F corrugated) corresponding to the entire outer surface of the cup body part 11 of the microwave oven paper cup G of Example 4-2 was made, and embedded in the cylindrical heat insulating cover 4 The paper cup G for a microwave oven is partially bonded and fixed to produce a paper cup G' for a microwave oven.

In the microwave paper cup G' of Example 4-4, since the undercut portion 3 of the paper cup a was folded inward, no scorching was found in any part of the paper cup when the contents were loaded and heated and cooked in a microwave oven. . And, on the cup body part 11, install the heat-insulating cover 4 with corrugated cardboard as material, thus have heat-insulating property, and the content that is heated is not easy to become cold, and in addition, it is difficult to feel the heat of content, can touch with hand And pick up the microwaveable paper cup G'.

[Example 5-1]

As Example 5-1 of the paper cup for a microwave oven of the present invention, a paper cup H for a microwave oven shown in FIG. 26 was produced. On the cup body part 1, a material composed of cup base paper 280g/m ² /low density polyethylene resin 25μm is used from the surface, and on the cup bottom part 2, a cup base paper 255g/m ² is used from the surface / Low-density polyethylene resin 25μm material. The semi-finished cup body 10 shown in FIG. 3 is produced by a punching process, and the semi-finished cup body 10 is wound around a mandrel to form a cylindrical cup body 1a. Then, with a general paper cup forming machine, insert the cup bottom part semi-finished product 20 from the bottom of the cup body part 1a, heat the joint part with hot air, bend the outer peripheral edge part of the cup bottom part 2 downward to form the curved part 22, and make a cup bottom part 22. The paper cup e shown in FIG. 27 is the bonded portion 3' of the curved portion 22 and the lower end portion of the cup body member 1 by thermal compression. Then, the joint part 3' was curled inward to form the bottom curl part 3b, and the paper cup H for microwave ovens was produced.

On the paper cup H for microwave ovens of this Example 5-1, since the joint portion 3' of the paper cup e is rolled inwards, when the content is loaded and heated and cooked in a microwave oven, no damage is found in any part of the paper cup. burnt. Moreover, it has good stability on a plane.

[Example 5-2]

As Example 5-2 of the paper cup for a microwave oven of the present invention, the paper cup I for a microwave oven shown in FIG. 28 was produced. On the cup body part 1, a material composed of cup base paper 280g/m ² /low density polyethylene resin 25μm is used from the surface, and on the cup bottom part 2, a cup base paper 255g/m is used from the surface ² /Material composed of low density polyethylene resin 25μm. Paper cup a as the semi-finished product of paper cup 1 for microwave ovens is made in the same order as above-mentioned embodiment 1-1. The undercut portion 3 of the paper cup a is rolled inward to form a bottom curl portion 3c, and a paper cup 1 for a microwave oven is produced.

On the paper cup 1 for microwave ovens of this embodiment 5-2, since the undercut portion 3 of the paper cup a is drawn inwardly, when the content is loaded and heated and cooked in a microwave oven, it is not found that any part of the paper cup is damaged. burnt. Moreover, it has good stability on a plane.

[Example 5-3]

As Example 5-3 of the microwave oven paper cup of the present invention, a microwave oven paper cup H' shown in Fig. 30 was produced. A heat insulating cover 4 using a cylindrical corrugated cardboard (F corrugated) corresponding to the entire outer surface of the cup body part 11 of the microwave oven paper cup H of Example 5-3 was made, and embedded in the cylindrical heat insulating cover 4 The paper cup H for a microwave oven is partially bonded and fixed to produce a paper cup H' for a microwave oven.

The paper cup H' for microwave ovens of this Example 5-3, because the joint part 3' of the paper cup e is rolled inward, so when the content is loaded and heated and cooked in a microwave oven, no burning is found in any part of the paper cup. coke. And, on the cup body part 11, install the heat-insulating cover 4 with corrugated cardboard as material, thus have heat-insulating property, and the content that is heated is not easy to become cold, and in addition, it is difficult to feel the heat of content, can touch with hand And pick up the microwave paper cup H'.

(industrial field of use)

As described above, according to the first paper cup for microwave ovens of the present invention, it is possible to obtain paper cups for microwave ovens that do not cause scorching when contents such as beverages or instant foods are added to the paper cups and heated and cooked in a microwave oven.

According to the second paper cup for microwave ovens of the present invention, it is possible to obtain paper cups for microwave ovens that do not cause scorching when contents such as beverages or instant foods are added to the paper cups and heated and cooked in a microwave oven. In addition, the second microwave oven paper cup of the present invention has the effect that the heat of the content is not easily dissipated when placed on a flat surface because a space is provided between the bent portion of the undercut portion and the bottom portion of the bottom member.

In the third paper cup for microwave ovens of the present invention, since a bending portion is formed to bend the lower portion of the undercut portion of the paper cup inwardly, and a convex portion protruding inwardly is provided at the inner central portion of the bottom portion, Therefore, when a paper cup for a microwave oven is filled with content and used in a microwave oven, the shape of the convex part that protrudes toward the inside on the bottom surface will be reversed and become a shape that protrudes outward, which greatly reduces the bite of the paper cup. Paper cups for microwave ovens that may burn the edges.

In addition, the method of manufacturing paper cups for microwave ovens according to the present invention is to form the bending portion that bends the lower portion of the undercut portion of the paper cup inwardly, and does not provide vent holes in the pressing portion of the stamping die, but fixes the The mold portion is formed in a hollow cylindrical shape as a vent hole, thereby increasing the internal pressure and making it easier to form a convex portion that protrudes inwardly at the inner central portion of the bottom portion.

According to the first microwave oven paper cup of the present invention, the undercut portion of the cup body member and the cup bottom member is folded inward to form a bottom folded portion, thereby reducing the height of the undercut portion, and the cup bottom member The bottom part is concaved downward, so that when the content such as beverage or instant food is added to the paper cup and heated and cooked in a microwave oven, the content will not leak out and no part of the paper cup will be burnt. . In addition, since the heat-insulating cover made of a heat-insulating material is installed on the cup body, the heated contents are less likely to become cold, and a paper cup for a microwave oven that can be touched and picked up by hand can be obtained.

According to the 2nd paper cup for microwave oven of the present invention and its manufacturing method, because the joint portion of cup body member and cup bottom member is rolled inward and forms bottom curling portion, so can reduce to about 1 of the height of conventional undercut portion. /2 or less, it is possible to obtain a paper cup for microwave ovens that does not cause scorching when contents such as beverages or instant foods are added to the paper cups and heated and cooked in a microwave oven. In addition, the paper cup for a microwave oven has a high stability when placed on a flat surface because the bottom is made into a bottom curling portion, and since the bottom portion does not contact the flat surface, it also has the effect that the heat of the contents is not easily dissipated.

Claims (14)

1. A paper cup for a microwave oven, characterized in that: it has an undercut part that combines the cup body part and the cup bottom part on a paper cup made of a cup body part and a cup bottom part, and the undercut part Fold inward to shape. 2 . The paper cup for microwave oven according to claim 1 , wherein the bottom surface of the cup bottom member is concave inward. 3 . 3 . The paper cup for microwave oven according to claim 1 , wherein the bent portion is formed by bending the lower portion of the undercut portion inwardly by more than 90 degrees. 4 . 4 . The paper cup for microwave oven according to claim 3 , wherein the gap width of the space between the bent portion and the bottom surface of the cup bottom member is 5 mm or less at its maximum. 5 . The paper cup for microwave oven according to claim 4 , wherein a concave wedge is provided on the bending portion. 5 . 6. The paper cup for a microwave oven according to claim 1, wherein the cup body member is wound to form a cylindrical shape, and the outer peripheral edge portion of the cup bottom member is bent to form a bent portion. , the folded portion that folds the lower end portion of the cup body member and the cup body member sandwich the bent portion and combine to form the undercut portion, and the lower portion of the undercut portion is turned inward A bent portion is formed by bending, and a convex portion protruding inward is provided at an inner central portion of the bottom portion of the cup bottom member. 7 . The paper cup for microwave oven according to claim 6 , wherein the gap width of the space between the bending portion and the cup bottom member is 5 mm or less at its maximum. 8. The paper cup for microwave ovens according to claim 1, wherein the cup body is formed by winding the cup member in a cylindrical shape, and the upper end side of the cup body is bent to form an upper curled portion. , and the front end of the bent portion formed by bending the outer peripheral edge of the cup bottom member is arranged toward the lower end side of the cup body, and the folded portion folded from the lower end of the cup body is in contact with the The cup body sandwiches the curved portion to form the undercut portion, thereby combining the cup body member and the cup bottom member with each other, and folding the lower portion of the undercut portion inward. 9. The paper cup for a microwave oven according to claim 8, wherein the bottom portion of the cup bottom member is formed in a concave shape downward from the inner surface side. 10. The paper cup for a microwave oven according to claim 1, wherein the cup body member is wound to form a cylindrical shape, and the outer peripheral edge portion of the cup bottom member is bent to form a bent portion. , and the cup portion of the cup member is combined with the curved portion to form a joint portion, and the joint portion is rolled inward to form a bottom beading portion. 11. The paper cup for microwave ovens according to claim 10, characterized in that: the joint portion clamps the bent portion between the folded portion formed by folding the lower end portion of the cup body and the cup body combined in a way. 12. A method of manufacturing paper cups for microwave ovens, characterized in that: winding and forming a cylindrical cup body member, bending the outer peripheral edge portion of the cup bottom member to form a bent portion, and forming a curved portion of the cup body member The folded portion where the lower end of the cup body is folded sandwiches the curved portion with the cup body to form an undercut portion, and the lower portion of the undercut portion is bent inward to form a bent portion. , at the same time, instead of providing a vent hole in the pressing part of the stamping die, the fixed die part is made into a hollow cylindrical shape as a vent hole, so as to form a protrusion toward the inside at the inner central part of the bottom surface of the cup bottom part. The convex part of the shape. 13. A method of manufacturing paper cups for microwave ovens, characterized in that: a cylindrical cup body member is formed by winding, the outer peripheral edge of the cup bottom member is bent to form a curved portion, and the cup body member The lower end of the cup body is joined to the curved portion to form a joined portion, and the joined portion is rolled inward to form a bottom bead. 14. The manufacturing method of paper cups for microwave ovens according to claim 13, characterized in that: said cup body sandwiches said The bending part is combined to form the joint part, and the joint part is rolled inward to form the bottom beading part.

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