Plastic-free paper cup and preparation method thereof

Abstract

The invention provides a plastic-free paper cup and a preparation method thereof, and belongs to the field of paper cups. The problem of leakage at the bottom of the plastic-free paper cup is solved. A plastic-free paper cup comprises a fanning strip and round backing paper, the inner side of the fanning strip and the inner side of the backing paper are coated with waterproof coatings, the fanning strip is wound to form a cup body, the edge of the backing paper is a bonding part, the bonding part is coated with a flexible coating with certain ductility and adhesion, the flexible coating extends towards the center of the backing paper by a certain distance and extends out of the bonding part, and the fanning strip is wound to form the cup body. When the bonding part is bent downwards to form the cup bottom, the flexible coating is bent to form an L-shaped waterproof angle bead, the waterproof angle bead completely covers the bent position of the cup bottom, the cup bottom is connected with the bottom of the cup body in a bonding mode through the flexible coating, and the paper cup with the sealed bottom is formed. The flexible coating with ductility is additionally arranged on the waterproof coating, the notch of the waterproof coating is sealed after bending, and leakage of the cup bottom is avoided while bonding is completed.

Description

Technical Field

[0001] This invention belongs to the field of paper cups, and specifically relates to a plastic-free paper cup and its preparation method. Background Technology

[0002] Paper cups, as disposable containers made from chemical wood pulp through mechanical processing and bonding, are widely used in various occasions due to their safety, hygiene, lightness, and convenience. However, with increasing attention to environmental protection, the polyethylene plastic film used in traditional paper cups is non-degradable, making it difficult to effectively recycle discarded paper cups. To meet environmental protection requirements and usage standards, existing paper cups usually use a plastic-free coating instead of a plastic film. However, because the plastic-free coating is brittle, it is prone to breakage when the bottom paper is bent, causing the waterproof function at the bottom bend to fail. This allows the liquid inside the cup to easily leak from the bottom bend, which not only affects the user experience but also reduces the structural strength of the cup under the influence of the liquid. Summary of the Invention

[0003] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a plastic-free paper cup. The technical problem to be solved by this invention is: how to avoid leakage at the bottom of the plastic-free paper cup.

[0004] The objective of this invention can be achieved through the following technical solution: a plastic-free paper cup, comprising a fan-shaped sheet and a circular bottom paper, wherein the inner sides of both the fan-shaped sheet and the bottom paper are coated with a waterproof coating, and the fan-shaped sheet is rolled up to form the cup body. The bottom paper has an adhesive edge, and the adhesive edge is coated with a flexible coating possessing a certain degree of extensibility and adhesion. The flexible coating extends a certain distance towards the center of the bottom paper and extends out to form the adhesive edge. When the adhesive edge bends downwards to form the cup bottom, the flexible coating bends to form an L-shaped waterproof corner protector. The waterproof corner protector completely covers the bend in the cup bottom. The cup bottom and the bottom of the cup body are bonded together by the flexible coating, forming a bottom-sealed paper cup.

[0005] This application mainly includes a fan-shaped sheet and a circular bottom paper. A waterproof coating is applied to the bottom paper and the inner side of the fan-shaped sheet. The waterproof coating prevents liquid from siphoning along the paper fibers and reducing the structural strength of the cup. An adhesive part is formed by bending the edge of the bottom paper, leaving space for the adhesion between the cup body and the bottom. However, due to the brittleness of the waterproof coating, it is prone to breakage at the bend of the bottom after bending the adhesive part. This can cause liquid to seep into the paper substrate at the bottom of the cup, affecting its use. To avoid this problem, this application applies an additional flexible coating to the adhesive part, extending the flexible coating a certain distance towards the center of the bottom paper to expand its coverage. Because the flexible coating has a certain degree of extensibility, when the edge of the bottom paper is bent, the flexible coating bends along with it to form a waterproof corner protector, covering the bend of the bottom of the cup, i.e., the break of the waterproof coating at the bottom of the cup. This prevents liquid from directly contacting the paper substrate at the bottom of the cup, avoiding leakage of the plastic-free paper cup and improving the user experience.

[0006] In the aforementioned plastic-free paper cup, when the bottom paper is bent to form the cup bottom, the waterproof coating at the bend breaks, creating a gap. The waterproof corner protectors cover the gap and seal it. By covering the gap with the waterproof corner protectors, liquid leakage from the cup bottom is prevented.

[0007] In the aforementioned plastic-free cup, the bottom of the cup body is bent inward to form a U-shaped foot, which wraps around the edge of the bottom paper. After the adhesive portion is bent to form the cup bottom, the foot wraps around the adhesive portion and is bonded to it through a flexible coating. By bending the bottom of the cup body to form a U-shaped foot, the contact and bonding area between the cup body and the adhesive portion is increased, thereby improving the bonding stability between the two.

[0008] In the aforementioned plastic-free paper cup, one side edge of the outer wall of the fan-shaped piece is coated with a flexible coating, and the two sides of the fan-shaped piece are bonded together by the flexible coating after being rolled and stacked.

[0009] In the aforementioned plastic-free paper cup, the waterproof coating is a plastic-free coating.

[0010] In the aforementioned plastic-free cup, the fan-shaped sheet is either single-layered or double-layered.

[0011] In the aforementioned plastic-free paper cup, the double-layered fan-shaped sheet includes an inner cup paper and corrugated paper, with the corrugated paper adhered to the outer wall of the inner cup paper.

[0012] To produce the aforementioned plastic-free paper cups, this application can achieve the following technical solution: A method for preparing plastic-free paper cups for production, characterized by comprising:

[0013] S1. Feed the two rolls of paper into the cutting device for cutting to obtain a fan-shaped piece and a circular base paper;

[0014] S2. Apply a waterproof coating to both the fan-shaped sheet and the base paper;

[0015] S3. Apply the flexible coating to the edge of the waterproof coating on the backing paper, so that the flexible coating extends beyond the adhesive portion at the edge of the backing paper and extends a distance toward the center of the backing paper.

[0016] S4. The part of the bottom paper with a flexible coating is bent to form the bottom of the cup, and the flexible coating is bent to form an L-shaped waterproof corner protector;

[0017] S5. Roll the fan-shaped piece to form the cup body, and bend the bottom of the cup body to form the cup foot;

[0018] S6. Place the adhesive part at the bottom of the cup inside the cup foot, and glue the bottom of the cup to the cup body to form a paper cup.

[0019] In the aforementioned plastic-free paper cup, after the waterproof coating and flexible coating are applied, the waterproof coating and flexible coating are dried respectively.

[0020] In the aforementioned plastic-free paper cup, one side edge of the cup body is a sealing edge, which is coated with a flexible coating. After the fan-shaped piece is rolled up to form the cup, the other side edge of the fan-shaped piece is overlapped with and bonded to the sealing edge.

[0021] Compared with the prior art, the present invention has the following advantages:

[0022] 1. Based on existing paper cups, this application coats the inside of the paper cup with a plastic-free coating to meet environmental protection requirements. At the same time, it coats the edge of the bottom paper with an additional flexible coating that has an elasticity. When bent, the coating forms an L-shaped waterproof corner protector, which completely covers the part of the plastic-free coating that is broken when bent. This completes the barrier at the break point and prevents liquid from leaking from the break point, thus affecting the use effect. Attached Figure Description

[0023] Figure 1 This is a schematic diagram showing the unfolded shape of the cup body and the bottom of the present invention;

[0024] Figure 2 This is a three-dimensional schematic diagram of the present invention;

[0025] Figure 3 This is a cross-sectional schematic diagram of an embodiment of the present invention;

[0026] Figure 4 yes Figure 3 A magnified view of a portion of the image;

[0027] In the diagram, 1. Fan-shaped piece; 1a. Cup body; 1b. Cup foot; 1c. Rolled rim; 1d. Sealing edge; 2. Base paper; 2a. Adhesive part; 2b. Cup bottom; 3. Waterproof coating; 3a. Notch; 4. Flexible coating; 4a. Waterproof corner protector; Detailed Implementation

[0028] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments. In this embodiment, the number of cups is at least two, and the present invention mainly adopts a combination of three cups.

[0029] like Figure 1 and Figure 2 As shown, a plastic-free paper cup includes a circular bottom paper 2 and a fan-shaped piece 1. The circular bottom paper 2 includes an adhesive portion 2a located at the edge, and the adhesive portion 2a is additionally coated with a flexible coating 4. The flexible coating 4 extends a certain distance towards the center of the bottom paper 2. One end of the fan-shaped piece 1 has a sealing edge portion 1d, its bottom is a cup foot 1b that can be glued to the cup bottom 2b, and its top has a rolled edge 1c. The bottom paper is cut and formed on a paper cup machine.

[0030] like Figure 3 and Figure 4 As shown, a fan-shaped sheet 1 is rolled up to form a cup body 1a. The upper end of the cup body 1a is bent outward and rolled up to form a rolled mouth 1c. The bottom of the cup body 1a is bent inward to form a U-shaped cup foot 1b. The edge of the circular sheet is bent downward to form an adhesive part 2a. After assembly, the adhesive part 2a is placed inside the U-shaped cup foot 1b and is bonded to the inner wall of the cup foot 1b through a flexible coating 4. The method of using a single-layer fan-shaped sheet 1 to form a cup body 1a is only one embodiment of this application. Other schemes that use double or multiple layers of paper to form a fan-shaped sheet 1 are simply paper stacking and are equivalent to this application.

[0031] It is worth mentioning that, such as Figure 1 as well as Figure 4 As shown, the inner sides of the cup body 1a and the cup bottom 2b are coated with a waterproof coating 3. The adhesive part 2a of the cup bottom 2b is additionally coated with a flexible coating 4, which covers the outer side of the waterproof coating 3. After the adhesive part 2a is bent downward to form the cup bottom 2b, the waterproof coating 3 located at the bend of the bottom paper 2 breaks and forms a gap 3a. The flexible coating 4 bends downward together with the adhesive part 2a to form an L-shaped waterproof corner protector 4a. The L-shaped waterproof corner protector 4a covers the gap 3a and forms a seal.

[0032] This application relates to a plastic-free paper cup, and its processing method is as follows:

[0033] S1. Feed the two rolls of paper into the cutting device for cutting to obtain a fan-shaped piece 1 and a circular base paper 2.

[0034] S2. Apply waterproof coating 3 to the fan-shaped sheet 1 and the base paper 2 respectively and dry them;

[0035] S3. Apply the flexible coating 4 to the edge of the base paper 2 with the waterproof coating 3, so that the flexible coating 4 extends out of the adhesive portion located at the edge of the base paper 2 and extends a distance toward the center of the base paper 2, and then dry the flexible coating 4.

[0036] S4. Bend the part of the bottom paper 2 with the flexible coating 4 at the edge to form the cup bottom 2b;

[0037] S5. The fan-shaped piece 1 is rolled up to form the cup body 1a. One end of the fan-shaped piece 1 is bonded to the sealing edge 1d, and the bottom of the cup body 1a is bent to form the cup foot 1b.

[0038] S6. Place the adhesive part 2a of the cup bottom 2b inside the cup foot 1b, and heat-seal the cup bottom 2b to the cup body 1a.

[0039] This application, based on conventional paper cups, reduces the plastic content in the waterproof coating 3 by coating the inner sides of the fan-shaped sheet 1 and the bottom paper 2 with a mineral-containing waterproof coating 3, enabling the paper cup to meet corresponding environmental protection standards and reducing the environmental damage caused by discarded traditional paper cups. However, because the mineral-containing waterproof coating 3 is brittle, it will break and form a gap 3a when the adhesive part 2a is bent due to a certain degree of stretching on the upper surface of the bottom paper 2. When the paper cup is filled with liquid, the liquid will enter the gap 3a and come into contact with the bottom paper 2, siphoning along the paper fibers, resulting in a decrease in structural strength and leakage at the bottom 2b of the cup. To avoid the above problems, this application uses the waterproof coating 3... Based on this, a flexible coating 4 is applied to the adhesive part 2a, extending a certain distance towards the center of the bottom paper 2. Due to the extensibility of the flexible coating 4, when the adhesive part 2a is bent, the flexible coating 4 located above the bottom paper 2 is stretched by the bending effect to form an L-shaped waterproof corner protector 4a. The bent part of the waterproof corner protector 4a just covers the gap 3a at the break, blocking the entry of liquid and water vapor and preventing leakage from the bottom 2b of the cup. Furthermore, by adding the process of applying a flexible coating 4 and drying it after applying and drying the waterproof coating 3 on the basis of the traditional paper cup, the flexible coating 4 is tightly bonded to the waterproof coating 3 to form a seal, thereby improving the waterproof effect.

[0040] It is worth mentioning that, since the waterproof coating 3 contains minerals and does not contain non-degradable polymer materials such as plastics, the waterproof coating 3 does not have adhesive properties. Therefore, a flexible coating 4 with a certain degree of adhesion is applied to the edge of the sealing part 1d at one end of the fan-shaped piece 1 and the edge of the bottom paper 2. The bent adhesive part 2a is inserted into the bent cup foot 1b to increase the contact area between the cup foot 1b and the adhesive part 2a. The cup foot 1b and the adhesive part 2a are bonded together by heating and applying a certain pressure, which improves the stability of the bond and forms a seal with the bottom 2b of the cup, thereby improving the user experience of the paper cup.

[0041] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0042] Although this document frequently uses terms such as 1. fan-shaped piece; 1a. cup body; 1b. cup foot; 1c. rolled edge; 1d. sealing edge; 2. bottom paper; 2a. adhesive part; 2b. cup bottom; 3. waterproof coating; 3a. notch; 4. flexible coating; 4a. waterproof corner protector, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of this invention; interpreting them as any additional limitation would contradict the spirit of this invention.

Claims

1. A plastic-free paper cup, comprising a fan-shaped sheet (1) and a circular bottom paper (2), wherein the inner sides of both the fan-shaped sheet (1) and the bottom paper (2) are coated with a waterproof coating (3), and the fan-shaped sheet (1) is rolled to form a cup body (1a), characterized in that, The edge of the bottom paper (2) is an adhesive part (2a). The adhesive part (2a) is coated with a flexible coating (4) with certain extensibility and adhesion. The flexible coating (4) extends a certain distance towards the center of the bottom paper (2) and extends out of the adhesive part (2a). When the adhesive part (2a) bends downward to form the bottom of the cup (2b), the flexible coating (4) bends to form an L-shaped waterproof corner protector (4a). The waterproof corner protector (4a) completely covers the bend of the bottom of the cup (2b). The bottom of the cup (2b) is bonded to the bottom of the cup body (1a) through the flexible coating (4) to form a bottom-sealed paper cup.

2. The plastic-free paper cup according to claim 1, characterized in that, When the bottom paper (2) is bent to form the bottom of the cup (2b), the waterproof coating (3) at the bend of the bottom paper (2) breaks to form a gap (3a), and the waterproof corner protector (4a) covers the gap (3a) and seals the gap (3a).

3. The plastic-free paper cup according to claim 2, characterized in that, The bottom of the cup body (1a) is bent inward to form a U-shaped cup foot (1b) and wraps around the edge of the bottom paper (2). After the adhesive part (2a) is bent to form the cup bottom (2b), the cup foot (1b) is wrapped around the adhesive part (2a) and is bonded to the adhesive part (2a) by a flexible coating (4).

4. The plastic-free paper cup according to claim 3, characterized in that, One side edge of the outer wall of the fan-shaped piece (1) is coated with a flexible coating (4), and the two sides of the fan-shaped piece (1) are bonded together by the flexible coating (4) after being rolled and stacked.

5. The plastic-free paper cup according to claim 4, characterized in that, The waterproof coating (3) is a plastic-free coating.

6. The plastic-free paper cup according to any one of claims 1 to 5, characterized in that, The sector-shaped piece (1) is a single layer or a double layer.

7. The plastic-free paper cup according to claim 6, characterized in that, The double-layered fan-shaped sheet (1) includes an inner cup paper and a corrugated paper, wherein the corrugated paper is adhered to the outer wall of the inner cup paper.

8. A method for preparing a plastic-free paper cup, characterized in that, include: S1. Feed the two rolls of paper into the cutting device for cutting to obtain a fan-shaped piece (1) and a circular base paper (2); S2. Apply a waterproof coating (3) to the fan-shaped sheet (1) and the base paper (2) respectively; S3. Apply the flexible coating (4) to the edge of the backing paper (2) with the waterproof coating (3), so that the flexible coating (4) extends out of the adhesive part located at the edge (2) of the backing paper and extends a distance toward the center of the backing paper (2); S4. The part of the bottom paper (2) with the flexible coating (4) on the edge is bent to form the bottom of the cup (2b), and the flexible coating (4) is bent to form an L-shaped waterproof corner guard (4a); S5. Roll the fan-shaped piece (1) to form the cup body (1a), and bend the bottom of the cup body (1a) to form the cup foot (1b); S6. Place the adhesive part (2a) of the cup bottom (2b) inside the cup foot (1b) and glue the cup bottom (2b) to the cup body (1a) to form a paper cup.

9. The method for preparing a plastic-free paper cup according to claim 8, characterized in that, After applying the waterproof coating (3) and the flexible coating (4), the waterproof coating (3) and the flexible coating are dried (4) respectively.

10. The method for preparing a plastic-free paper cup according to claim 8, characterized in that, One side edge of the fan-shaped piece (1) is a sealing edge (1d), and the sealing edge (1d) is coated with a flexible coating (4). After the fan-shaped piece (1) is rolled up to form a cup body (1a), the other side edge of the fan-shaped piece (1) is bonded to the sealing edge (1d).

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