Paper Cup and Its Manufacturing Process

Abstract

The present paper cup comprises a cup body, and the cup body comprises inner paper and outer paper. There are hollow bulges on the outer paper, and the outer paper forms a connecting part. The inner side of the connecting part bonds to the outer side of the inner paper, and the cup rim of the outer paper extends to the cup rim of the inner paper. In addition, the outer side of the cup rim of the inner paper bonds to the inner side of the outer paper, and both cup rims of the outer paper and the inner paper bend outward to form a double layered crimping. The manufacturing process for the present paper cup includes: paper preparation, rolling, composition, sheet cutting, forming, molding and etc.

Claims

1. A paper cup comprising: a cup body (1), the cup body (1) having an inner paper (11) and an outer paper (12); several hollow bulges (121) on the outer paper (12), the hollow bulges (121) project outward and are capable of preventing scalding; a connecting part (122) formed at a part of the outer paper (12) located in between two adjacent hollow bulges (121); an inner side of the connecting part (122) that bonds to an outer side of the inner paper (11); a cup rim of the outer paper (12) that extends to a cup rim of the inner paper (11); an outer side of the cup rim of the inner paper (11) bonds to the inner side of the cup rim of the outer paper (12); a double layered crimping (3) formed by bending outward both cup rims of the outer paper (12) and the inner paper (11); and a cup bottom (4) fixed to a bottom part of the cup body (1); wherein both the inner paper (11) and the outer paper (12) are single layered papers; and wherein a cross section of the crimping is annular.

2. The paper cup of claim 1 wherein the connecting part (122) is in an annular or a continuous strip shape; and wherein a width of the connecting part (122) is 4 mm-12 mm.

3. The paper cup of claim 2 wherein weights of the outer paper (12) and the inner paper (11) are both 100 grams per square meter to 170 grams per square meter.

4. The paper cup of claim 1 wherein an outer rim of the cup bottom (4) bends downward to form a supporting flange (41); wherein a bottom rim of the cup body (1) bends inward; and wherein an inner side of the inner paper (11) bonds to an inner side of the supporting flange.

5. The paper cup of claim 1 wherein the connecting part (122) is in a form of a strip or a block; and wherein a plurality of connecting parts (122) is arranged on an outer side surface of the paper cup to form a decorative design.

6. The paper cup of claim 5 wherein the connecting part (122) has a width of 1 mm to 12 mm.

7. A method of manufacturing paper cups, the method comprising: winding an outer paper (12) into a reel, wherein a weight of the outer paper (12) is 100 grams per square meter to 170 grams per square meter; winding an inner paper (11) into a reel, wherein a weight of the inner paper (11) is 100 grams per square meter to 170 grams per square meter; unwinding the outer paper (12); rolling several embossed patterns onto the outer paper (12); bonding a first side of the rolled outer paper (12) to a first side of the inner paper (11) to form a double layered paper (9), such that the embossed patterns on a second side of the outer paper (12) form hollow bulges (121); unfolding the double layered paper (9); die cutting the double layered paper (9) into fan-shaped cup sheets (2) with two opposite straight edges and two opposite arc edges; winding each cup sheet (2) into a cup body (1) that is cylindrical with a diameter tapering from a top to a bottom of the cup body (1); bonding the two straight edges of the cup sheet (2); bending a cup rim of the double layered paper (9) outward to form a crimping (3) with an annular cross section; bending a bottom rim of the cup body (1) inward; and adhering the bottom rim of the cup body (1) to an inner side of a supporting flange (41) of the cup bottom (4) by hot pressing.

8. The method of manufacturing paper cups of claim 7, further comprising: during the rolling step, passing the outer paper (12) through a meshed convex roller (5) and a concave roller (6); wherein when the convex roller (5) and the concave roller (6) roll the outer paper (12), a temperature of the outer paper (12) is lower than 90° C., and a moisture content of the outer paper (12) is 5.5%-7%; wherein after the passing step, a height of the embossed patterns on the outer paper (12) is 0.3 mm-1 mm; and wherein the rolled outer paper (12) adheres to a first side of the concave roller (6) and rotates with the concave roller (6) to get to a second side of the concave roller (6) before proceeding to the step of bonding a first side of the rolled outer paper (12) to a first side of the inner paper (11).

9. The method of manufacturing paper cups of claim 8, further comprising: during the step of bonding a first side of the rolled outer paper (12) to a first side of the inner paper (11), adhering the outer paper (12) to an outer side of the concave roller (6); during the step of bonding a first side of the rolled outer paper (12) to a first side of the inner paper (11), adhering the inner paper (11) to an outer side of a round roller (7), wherein the outer paper (12) and the inner paper (11) approach and abut each other; and before the outer paper (12) abuts on the inner paper (11), either locating a spraying head (8) above a gap between the concave roller (6) and the round roller (7), and coating film on opposite sides of the outer paper (12) and the inner paper (11) simultaneously, or locating a gluing head above the gap between the concave roller (6) and the round roller (7), and coating glue on opposite sides of the outer paper (12) and the inner paper (11) simultaneously; wherein when the outer paper (12) is bonded to the inner paper (11) through glue coating, an amount of glue usage is 5 grams per square meter to 15 grams per square meter; and wherein when the outer paper (12) is bonded to the inner paper (11) through film coating, a thickness of the film coating is 0.007 mm-0.018 mm.

10. The method of manufacturing paper cups of claim 9, further comprising: locally smoothening a first side of the outer paper (12) using pressure from the round roller (7) and the concave roller (6), wherein the pressure against the outer paper (12) and the inner paper (11) is 40-N−80 N; and adhering the first side of the outer paper (12) to a first side of the inner paper (11), forming a connecting part (122) between adjacent hollow bulges (121); wherein the round roller (7) is a rubber roller with Shore hardness of 45-95; and wherein a width of the connecting part (122) is 1 mm-2 mm.

11. The method of manufacturing paper cups of claim 7, further comprising: during the rolling step, uniformly distributing the rolled embossed patterns on the outer paper (12); and between the step of bonding a first side of the rolled outer paper (12) to a first side of the inner paper (11) and the unfolding step, flattening the outer paper (12) with a hot press plate, so as to form several groups of embossed patterns; wherein each group of embossed patterns is arranged in a fan-shaped manner.

12. The method of manufacturing paper cups of claim 7, further comprising: during the step of bonding a first side of the rolled outer paper (12) to a first side of the inner paper (11), using the concave roller (6) and the convex roller (5) to roll several groups of orderly spaced embossed patterns onto the outer paper (12), making an area between two adjacent embossed patterns flat; and during the die cutting step, die cutting a fan-shaped cup sheet (2) containing one group of embossed patterns, wherein edges of the cup sheet (2) are smooth.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 is a sectional view of one embodiment of the paper cup.

[0035] FIG. 2 is a flow chart of the manufacturing process for one embodiment of the paper cup.

[0036] FIG. 3 is a simplified flow chart of Steps B and C.

[0037] FIG. 4 is a schematic view of one embodiment of the cup sheet.

[0038] FIG. 5 is a schematic view of one embodiment of the double layered paper that is not die cut yet in the second embodiment.

[0039] FIG. 6 is a flow chart of the manufacturing process for the paper cup in the fifth embodiment.

[0040] FIG. 7 is a cup face design in the Sixth Embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0041] The embodiments of this invention will be described below and the technical solutions of the invention will be further illustrated in connection with the accompanying figures. However, the present invention shall not be limited to these embodiments.

First Embodiment

[0042] As shown in FIG. 1, a paper cup comprises a cup body (1), and the cup body (1) comprises inner paper (11) and outer paper (12). Both of the inner paper (11) and the outer paper (12) are single layered paper. On the outer paper (12), there are several hollow bulges (121) which projects outward and is used for an anti-scald purpose. Part of the outer paper (12) locating in between two adjacent hollow bulges (121) forms a connecting part (122). The inner side of the connecting part (122) bonds to the outer side of the inner paper (11), the cup rim of the outer paper (12) extends to the cup rim of the inner paper (11), and the outer side of the cup rim of the inner paper (11) bonds to the inner side of the cup rim of the outer paper (12). Both of the cup rims of the outer paper (12) and the inner paper (11) bend outward to form a double layered crimping (3), and the cross section of the crimping is annular. The outer paper (12) is bended into orderly arranged hollow bulges (121). After the inner side of the connecting part (122) is bonded to the outer side of the inner paper (11), the air in two adjacent hollow bulges (121) is isolated and does not communicate with each other. When the cup body (1) is held in hand, the hand presses against the outer surface of the hollow bulges (121). At this point, the inner cavity of the hollow bulge (121) insulates the heat transfer, making the heat not transfer to the outer surface of the hollow bulges (121), and hence it has a fairly good anti-scald effect. Further, since the hand presses against the hollow bulges (121) when the cup body (1) is held in hand, the hollow bulges (121) plays a role in strengthening the stiffness, presenting a fairly good supporting effect to the cup body (1), and hence improve the strength of the cup body (1). Still further, since the lower end of the cup body (1) is supported by the cup bottom (4), and the cup mouth on the upper end is annular, the rim of the cup body (1) bends outward to form a crimping (3) of a double layered paper structure. The crimping (3) also plays a role as stiffener, so as to improve the strength of the cup rim of the cup body (1) and prevent the cup rim from collapsing inward to deform the cup body (1). Therein, the inner paper (11) of the crimping (3) bonds to the outer paper (12), so the inner paper (11) integrates with the outer paper (12), and it has a relatively high supporting strength.

[0043] Specifically, when the cup body (1) is held in hand, the cup body (1) is subjected to radial forces. Therefore, the connecting part (122) is annular and arranged around the inner paper (11). In addition, several connecting parts (122) are arranged along the height of the cup body (1). Namely, the hollow bulge (121) is annular and each hollow bulge (121) can bear certain radial forces. Combined with the arrangement along height of the cup body (1), multiple hollow bulges (121) have a relatively high supporting strength to the cup body (1). The width of the connecting part (122) is 8 mm. There is a certain connecting area between the connecting part (122) and the inner paper (11). The connecting area strengthens the connection strength between the outer paper (12) and the inner paper (11), as well as the supporting strength of the cup body (1). Of course, during the actual manufacturing process, the connecting part (122) may be in a continuous strip shape, making the hollow bulge (121) be in a continuous strip shape too, or making the hollow bulge (121) be in a round or polygon shape. All of them have a relatively good supporting strength. Since hollow bulges (121) are evenly arranged on the cup body (1), and the crimping (3) uses a bonded double layered paper structure, the cup body (1) has a relatively high supporting strength. Therefore, the thicknesses of the inner paper (11) and the outer paper (12) can be reduced. Namely, the weights of both of the inner paper (11) and the outer paper (12) can be reduced to 130 grams per square meter. This saves the paper usage, is more environment friendly and reduces the production cost. The outer rim of the cup bottom (4) bends downward to form a supporting flange (41). The bottom rim of the cup body (1) bends inward, and the inner side of the inner paper (11) bonds to the inner side of the supporting flange. The main purpose of the supporting flange (41) is to support the cup body (1), but it can also improve the strength of the cup bottom (4). The lower end of the cup body (1) can be bended inward to wrap the supporting flange (41). Namely, the structure supporting the cup body is a five-layer-paper structure: the inside and outside layers of outer paper (12), the inside and outside layers of inner paper (11), and the supporting flange (41). This has a relatively strong supporting effect.

[0044] As shown in FIG. 2, FIG. 4 and FIG. 5, the manufacturing process for the paper cup is characterized in comprising the following steps:

[0045] A. Paper Preparation: Wind the outer paper (12) into a reel, and wind the inner paper (11) into a reel too. Therein, the weights of the outer paper (12) and the inner paper (11) are both 130 grams per square meter.

[0046] B. Rolling: Unwind the outer paper (12) and roll several embossed patterns onto the outer paper (12).

[0047] C. Composition: Bond one side of the rolled outer paper (12) to the side of the inner paper (11) to form double layered paper (9), such that the embossed patterns on the other side of the outer paper (12) form the hollow bulges (121).

[0048] D. Sheet Cutting: Unfold the double layered paper and die cut into fan-shaped cup sheets with two opposite straight edges and two opposite arc edges.

[0049] E. Forming: Wind the cup sheet (2) into a cup body (1) which is cylindrical but with diameter tapering from top to bottom, then bond the two straight edges of the cup sheet (2), and then bend the cup rim of the double layered paper (9) outward to form a crimping (3) with an annular cross section.

[0050] F. Molding: Bend the bottom rim of the cup body (1) inward and adhere it to the inner side of the supporting flange (41) of the cup bottom (4) by hot pressing.

[0051] In one embodiment of the process, the weights of the inner paper (11) and the outer paper (12) are limited to 130 grams per square meter, so as to save the paper usage and reduce the production cost. Regarding the issue of insufficient strength resulting from the reduction of the paper usage, several embossed patterns are rolled on the outer paper (12), and then the outer paper (12) and the inner paper (11) are bonded together before being wound into the cylindrical cup body (1). Hence, hollow bulges (121) having a relatively high supporting strength are formed to improve the supporting strength of the cup body (1). Compared to the conventional process, where the outer paper (12) is wound into a cylindrical outer cup body, the inner paper (11) is wound into a cylindrical inner cup body, and then the outer cup body is sleeved over and bonded to the inner cup body, in the process, the inner paper (11) is first bonded with the outer paper (12) having embossed patterns, so as to ensure a fairy good integrity of the inner paper (11) and the outer paper (12) before they are wound into the cylindrical cup body (1). In addition, the connection quality is better when the unrolled outer paper (12) is bonded to the unrolled inner paper (11), which eliminates local voids due to insufficient bonding strength or some other reasons. Then, double layered paper (9) with a better connection quality and connection stability is wound into cylindrical cup body (1), so that the cup body (1) has a relatively high supporting strength. Therein, the two edges of the cup sheet (2) are bonded after it is wound. The seaming line may be along the axis o the cup body (1), and of course, may be inclined relative to it. Further, in the process, the bonded double layered paper (9) is bended to form the crimping (3). The crimping (3) also plays a role as stiffener, so as to improve the strength of the cup rim of the cup body (1) and prevent the cup rim from collapsing inward to deform the cup body (1). Therein, both of the inner paper (11) and the outer paper (12) of the crimping (3) are bonded, so this can avoid the deformation of one layer of paper due to the deformation of the other layer of paper. The inner paper (11) and the outer paper (12) are integrated and have a relatively high supporting strength. Still further, since the connection quality between the inner paper (11) and the outer paper (12) is relatively high, the hollow bulges (121) will not collapse inward to touch the inner paper (11) when subjected to forces. Therefore, when the cup body (1) is held in hand, the hollow bulges (121) can always provide stable insulation space, ensuring a fairly good anti-scald effect.

[0052] Specifically, as shown in FIG. 3, in step B, the outer paper (12) passes through the meshed convex roller (5) and concave roller (6). When the outer paper (12) is subjected to the pressure from the convex roller (5) and the concave roller (6) and deforms, the temperature and humidity of the outer paper (12) determines the extent and stability of the outer paper (12) deformation. Therefore, in this embodiment, when the convex roller (5) and the concave roller (6) roll the outer paper (12), the temperature of the outer paper (12) is 85° C., and the moisture content of the outer paper (12) is 6.25%, making the quality of the embossed patterns rolled on the outer paper (12) higher. The height of the embossed patterns on the outer paper (12) is 0.7 mm-1 mm. Here, the height of the embossed patterns will affect the height of the hollow bulges (121) after the outer paper (12) is bonded to the inner paper (11) in Step C, and further affects the supporting strength and anti-scald effect of the cup body (1). The rolled outer paper (12) adheres to the concave roller (6) and rotates with the concave roller (6) to get to the other side of the concave roller (6) and proceed to step C. In step C, the outer paper (12) adheres to the outer side of the concave roller (6), and the inner paper (11) adheres to the outer side of the round roller (7). The outer paper (12) and the inner paper (11) approach and abut to each other. Therein, before the outer paper (12) abuts on the inner paper (11), they need to be film coated with a film coating machine. The spraying head (8) of the film coating machine is placed above the gap between the concave roller (6) and the round roller (7), so the sides of both outer paper (12) and the inner paper (11) have film coating before they abut on each other. Then they are bonded under force, allowing the outer paper (12) and the inner paper (11) to have a relatively high connection strength and stability. In Step C, the round roller (7) and the concave roller (6) make one side of the outer paper (12) locally unrolled and bonded to the side of the inner paper (11), hence forming the connecting part (122) located between two adjacent hollow bulges (121). The pressures against the outer paper (12) and the inner paper (11) from the round roller (7) and the concave roller (6) affect the connection strength between the outer paper (12) and the inner paper (11). Namely, when the pressure is too big, the adhesive between the outer paper (12) and the inner paper (11) is squeezed out, resulting in insufficient connection strength; when the pressure is too small, voids are prone to occur between the outer paper (12) and the inner paper (11), resulting in insufficient connection strength. Correspondingly, the bonding surface area intuitively reflects the connection strength between the outer paper (12) and the inner paper (11), while the height of the hollow bulge (121) intuitively reflects the size of the insulation cavity. When the width of the bonding surface is bigger and the inner cavity of the hollow bulge (121) is smaller, the heat insulation effect is reduced. Considering the factors comprehensively, in this embodiment, when the width of the bonding surface is set to 8 mm, the connection strength between the outer paper (12) and the inner paper (11) is relatively high and the heat insulation effect is relatively good. The thickness of the film coating, when bonding through film coating is selected, determines the connection strength between the outer paper (12) and the inner paper (11). Too thick film coating wastes the film coating, while too thin film coating results in insufficient connection strength. Therefore, in this embodiment, the thickness of the film coating when the outer paper (12) and the inner paper (11) are bonded with film coating is 0.012 mm. In step B, the rolled embossed patterns are uniformly distributed on the outer paper (12). Between steps C and D, the outer paper (12) is pressed and flattened with a hot press plate, so as to form several groups of embossed patterns. Each group of embossed patterns is arranged in a fan-shaped pattern. First the outer paper (12) is locally pressed and flattened with a hot press plate, so as to form several groups of embossed patterns, and then in Step D, several groups of embossed patterns are die cut. A group of embossed patterns corresponds to a cup sheet (2), and the flattened part pressed by the hot press plate forms the smooth edges of the cup sheet (2).

Second Embodiment

[0053] The manufacturing process for the paper cup of this embodiment is basically the same as that of the first embodiment. The differences are:

[0054] In step B, the concave roller (6) and the convex roller (5) roll several groups of embossed patterns arranged with orderly spacing onto the outer paper (12), making the area between two adjacent embossed patterns flat. In step D, a fan-shaped cup sheet (2) containing one group of embossed patterns is die cut, and the edges of the cup sheet (2) is smooth.

Third Embodiment

[0055] The manufacturing process for the paper cup of this embodiment is basically the same as that of the first embodiment. The differences are:

[0056] In Step A, the weights of the outer paper (12) and the inner paper (11) are both 100 grams per square meter.

[0057] In step B, when the convex roller (5) and the concave roller (6) roll the outer paper (12), the temperature of the outer paper (12) is 80° C., and the moisture content of the outer paper (12) is 5.5%. After rolling, the height of the embossed patterns on the outer paper (12) is 0.3 mm.

[0058] In step C, the pressure of the round roller (7) and the concave roller (6) against the outer paper (12) and the inner paper (11) is 40 N, and the width of the connecting part is 1 mm. When the outer paper (12) is bonded to the inner paper (11) with film coating, the thickness of the film coating is 0.007 mm.

Fourth Embodiment

[0059] The manufacturing process for the paper cup of this embodiment is basically the same as that of the first embodiment. The differences are:

[0060] In Step A, the weights of the outer paper (12) and the inner paper (11) are both 170 grams per square meter.

[0061] In step B, when the convex roller (5) and the concave roller (6) roll the outer paper (12), the temperature of the outer paper (12) is 75° C., and the moisture content of the outer paper (12) is 7%. After rolling, the height of the embossed patterns on the outer paper (12) is 1 mm.

[0062] In step C, the pressure of the round roller (7) and the concave roller (6) against the outer paper (12) and the inner paper (11) is 80 N, and the width of the connecting part is 12 mm. When the outer paper (12) is bonded to the inner paper (11) with film coating, the thickness of the film coating is 0.018 mm.

[0063] The embodiments stated above select 3 combinations of process parameters. Of course, other combinations are also applicable.

Fifth Embodiment

[0064] The manufacturing process for the paper cup of this embodiment is basically the same as that of the first embodiment. The differences are:

[0065] As shown in FIG. 6, in step C, the outer paper (12) adheres to the outer side of the concave roller (6), and the inner paper (11) adheres to the outer side of the round roller (7). The outer paper (12) and the inner paper (11) approach and abut to each other. Therein, before the outer paper (12) abuts on the inner paper (11), they need to be glue coated with a glue coating machine. Specifically, the gluing head is located above the gap between the concave roller (6) and the round roller (7), and glue coat the opposite sides of the outer paper (6) and the inner paper (11) simultaneously. The sides of both outer paper (12) and the inner paper (11) have glue coating before they abut on each other. Then they are bonded under force, allowing the outer paper (12) and the inner paper (11) to have a relatively high connection strength and stability. Hence, the supporting strength and anti-scald effect of the cup body is provided. The amount of the glue usage, when bonding through glue coating is selected, determines the connection strength between the outer paper (12) and the inner paper (11). Excessive glue results in overflow of the glue and waste of the glue, while inadequate glue results in insufficient connection strength. Therefore, in this embodiment, the amount of glue usage is 10 grams per square meter. Of course, during the actual manufacturing process, when the outer paper (12) is bonded to the inner paper (11) through glue coating, the amount of glue usage may be 5 grams per square meter or 15 grams per square meter.

Sixth Embodiment

[0066] As shown in FIG. 7, the Sixth Embodiment is a paper cup having a special decorative design which employs the same structure and manufacturing process as those in the First Embodiment. The differences are:

[0067] The decorative pattern of the cup face is not annular and is, instead, formed by block shaped connecting parts 122 and a plurality of connecting parts 122 are arranged on the outer surface of the paper cup to form the decorative pattern; The width of the connecting parts 122 are 1 mm to 12 mm, and in this example, the best is 6 mm. This structure is not only able to provide an anti-scald effect but also a good strength, while using a relatively thin inner paper 11 and outer paper 12.

[0068] The description of the preferred embodiments thereof serves only as an illustration of the spirit of the invention. It will be understood by those skilled in the art that various changes or supplements in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

[0069] Although the terms of Inner paper (11), Outer Paper (12), Hollow Bulges (121) and etc. are often used herein, it does not exclude the possibility to use any other terms. Using such terms is only to describe or explain the nature of the present invention more conveniently. Any additional restrictions are contrary to the spirit of the present invention.

LIST OF REFERENCE NUMERALS

[0070] 1 Cup Body [0071] 11 Inner Paper [0072] 12 Outer Paper [0073] 121 Hollow Bulge [0074] 122 Connecting Part [0075] 2 Cup Sheet [0076] 3 Crimping [0077] 4 Cup Bottom [0078] 41 Supporting Flange [0079] 5 Convex Roller [0080] 6 Concave Roller [0081] 7 Round Roller [0082] 8 Spraying Head [0083] 9 Double Layered Paper