Straw

Abstract

To provide a straw with high strength for piercing a sealing film at an opening of a paper cup and with high durability against liquid in the paper cup.SOLUTION: A straw (1) is disclosed. The straw comprises a tubular straw body having an end (12) and formed of a substrate, where the substrate has a first long side, a second long side and a first thickness (t1). The first long side overlaps with the second long side to form an overlapping portion (3) having a second thickness (t2). In the straw (1), a ratio of the second thickness (t2) to the first thickness (t1) is smaller than 2.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a straw, and particularly to a straw that has a high strength to break through the sealing film at the opening of a paper cup and has high durability against liquids in the paper cup.

Background Art

[0002] Straws widely used for filling and drinking juice or soft drinks in hand-held paper cups are usually made of plastic materials. Currently, with the increasing social environmental awareness, the replacement from plastic straws to paper straws is progressing. However, paper straws have a problem that they are easily crushed when inserted into the sealing film at the opening of a paper cup because they are weaker in strength than plastic straws. In addition, paper straws tend to become softer than plastic straws and have inferior durability when immersed in liquids such as juice and soft drinks. Therefore, conventional paper straws require a thicker paper sheet to form the straw.

[0003] Furthermore, conventional paper straws are coated with a laminated film / coating film layer on them to obtain a better waterproof effect. However, the laminated film / coating film layer is usually selected from PE, wax, or fluorochemicals, and is not environmentally friendly. These paper straws are difficult to decompose in the natural environment if not recycled. Paper straws with a laminated film / coating film layer cannot be recycled, but can be recycled at a very high cost to separate the coating material from the paper material. Therefore, a low-cost recycling method is needed.

[0004] Furthermore, the conventional paper straw has good chemical stability, water resistance, oil resistance, low friction, and contains perfluoroalkyl compounds and polyfluoroalkyl compounds (PFAS), so it is widely used in materials that come into contact with food. However, PFAS is difficult to decompose in the natural environment, is harmful to the human body, and causes natural pollution. Therefore, paper straws containing PFAS or fluorene are gradually becoming unacceptable in the market.

[0005] In addition, in the prior art, there is a method of cutting a paper sheet into a predetermined shape and then bonding the cut paper sheets to form a straw with a chamfered tip. For this reason, a very complicated and time-consuming manufacturing process is required for mass production. Considering the strength of the paper straw, a thicker paper sheet is used and cut into a predetermined shape. However, in the process of scrolling the thick paper sheet cut prior to the bonding step, the cut thick paper sheet becomes difficult to scroll in order to bond and form the paper straw, and another problem occurs.

[0006] Another type of traditional straw is formed of a paper strip instead of a paper sheet. The paper pieces are curled obliquely or diagonally and bonded to form a paper straw. This type of straw has the same problem that a thicker paper piece is required to maintain strength. Also, since the bonding area of the straw is much larger than that of a straw made of a paper sheet, the risk of peeling of the bonding area of the straw formed of a thin paper piece becomes high.

[0007] Therefore, the applicant has disclosed a straw that improves the problems of the above-mentioned prior art.

Summary of the Invention

[0008] According to one aspect of the present invention, a straw is provided. The straw has an end portion and includes a tubular straw body formed of a base material. The base material has a first long side, a second long side, and a first thickness. The first long side overlaps the second long side to form an overlapping portion having a second thickness, and the ratio of the second thickness to the first thickness is less than 2.

Brief Description of the Drawings

[0009] The following drawings are drawn according to the embodiments and merely illustrate the concept of the present invention.

Figure 1A

Figure 1B

Figure 1C

Figure 2

Figure 3A

Figure 3B

Figure 4

Figure 5

Figure 6A

Figure 6B

Mode for Carrying Out the Invention

[0010] When reading the following detailed description, refer to all the figures of the present invention. All the figures of the present invention show different embodiments of the present invention by way of example and are helpful for those skilled in the art to understand how to implement the present invention. This example provides embodiments sufficient to demonstrate the spirit of the present invention, each embodiment does not conflict with other embodiments, and new embodiments can be implemented through any combination of them. That is, the present invention is not limited to the embodiments disclosed in this specification.

[0011] Unless otherwise restricted as defined in a specific example, the following definitions apply to the terms used throughout the specification.

[0012] FIG. 1A is a straw according to one embodiment of the present invention. FIG. 1B is a straw according to another embodiment of the present invention. FIG. 1C is a perspective view of the straw of FIG. 1B. FIG. 2 is another detailed view of the straw of FIG. 1A or FIG. 1B. FIG. 3A is a schematic side view of a base material of a straw according to one embodiment of the present invention. FIG. 3B is a schematic side view of a base material of a straw according to another embodiment of the present invention. FIG. 4 is a schematic diagram showing a planarized shape when a substrate according to one embodiment of the present invention is planarized, and also shows a partially enlarged view of an end portion of the straw.

[0013] Referring to FIGS. 1A to 4, FIGS. 1A to 4 show a straw 1 comprising a tubular straw body 11 having an end portion 12 and formed of a base material 2. The base material 2 has a first long side 13, a second long side 14, and a first thickness t1. The first long side 12 overlaps the second long side 14 to form an overlapping portion 3 having a second thickness t2. The end portion 12 is formed after sealing the overlapping portion 3 to form the tubular straw body 11. According to one embodiment of the present invention, the overlapping portion 3 is sealed by heating a degradable coating 4 using an ultrasonic processing machine. When the ultrasonic waves generated by the ultrasonic processing machine are irradiated, the degradable coating 4 melts, and the melted degradable coating 4 on the upper surface of the base material 2 adheres to the back surface of the base material 2. The degradable coating 4 is a non-plastic material and is different from conventional plastic coating materials such as PE, PP, PET, and PAL. Since the paper straw according to the present invention does not include a plastic coating, it is possible to recycle the paper straw to obtain pulp with reduced costs, and then reuse the pulp to manufacture a new paper straw. Candidates for the degradable coating material include an aqueous coating material or a functional packaging coating material such as polyacrylic acid, which functions as an excellent waterproof barrier. The materials of both the degradable coating 4 and the base material 2 are at least one of hydrolyzable and biodegradable. According to a preferred embodiment of the present invention, the materials of the degradable coating 4 and the base material 2 are both hydrolyzable and biodegradable.

[0014] During heat - sealing, an external force or pressure from, for example, a fixed part or a movable part arranged above and below the overlapping part 3 is applied to the overlapping part 3. Preferably, the fixed part is a fixed rod as a core provided parallel to the longitudinal direction LD inside the hollow core of the scroll base material 2. The fixed rod is cylindrical and can be made of a metal such as iron or stainless steel. The movable part is an ultrasonic head installed under the ultrasonic generation module. When performing the heat - sealing process, the ultrasonic head as a pressing body and the ultrasonic generator move downward to press the overlapping part 3. When the first long side 13 and the second long side 14 gradually converge and overlap to form the scroll - shaped base material 2 having the overlapping part 3, the scroll - shaped base material 2 moves along the inside of the guide tube, surrounds the fixed rod provided in the hollow core of the scroll - shaped substrate 2, and when the overlapping part 3 is heated and sealed, the pressing body presses the overlapping part 3 and applies a force or pressure against the fixed rod to the overlapping part 3. The ultrasonic head conducts ultrasonic waves from the ultrasonic generator and generates heat in the overlapping part 3. The degradable coating 4 on the overlapping part 3 of the base material 2 is heated, melted, and fixed to form the overlapping part 3. An external force obtained by adding the weight of the ultrasonic head and the weight of the ultrasonic generating device acts on the fixed rod due to gravity on this overlapping part 3. The pressure due to the external force is about 100 - 250 kg·m / s2.

[0015] As a result, the overlapping part 3 becomes denser and tougher than the base material 2 itself, and the ratio of the second thickness t2 to the first thickness t1 is less than 2. According to the present invention, since the overlapping part 3 of the straw 1 receives a force or pressure during heat - sealing, the material density of the overlapping part 3 is higher than the material density of the non - overlapping part 5 of the base material. Compared with the straw shown in FIG. 2 (the non - overlapping part 5 has the first thickness t1), since the liquid absorption rate is reduced, the durability against liquid is higher than that of a straw to which no force or pressure is applied. This effect achieved by the present invention is advantageous compared with the prior art.

[0016] Furthermore, the degradable coating 4 functions as a medium for sealing the overlapping portion 3 and does not require an adhesive. The material selected for the degradable coating 4 is water-based, helps to decompose easily in the natural environment, and can be recycled. This effect achieved by the present invention is advantageous compared to the prior art.

[0017] Referring to FIGS. 1A and 4, it is shown that the straw 1 of the present invention has an end portion 12 having a plane perpendicular to the longitudinal direction LD of the straw 1. Referring to FIGS. 1B and 4, it is shown that the straw 1 of the present invention has an end portion 12 having a plane inclined with respect to the longitudinal direction LD of the straw 1. Further, referring to FIG. 3, the straw 1 of the present invention has an overlapping portion 3 having two longitudinal sides 31 and 32 that are straight lines, and one of the two longitudinal sides 31 and 32 (for example, the first longitudinal side 31) is shown to be in a straight line with the sharp point / tip 16 of the straw 1. After the process of scrolling the base material 2 into a circular tube shape, the scrolled base material 2 is sealed and cut as shown in FIG. 1A or FIG. 1B to form the straw 1. According to the present invention, since the first longitudinal side 31 is in a straight line with the sharp point 16, and the sharp point has at least a part of the overlapping portion 3, the sharp point is strengthened. Therefore, the sharp point 16 of the straw 1 can easily pierce the sealing film of the disposable paper cup. The sealing film is heat-sealable and is generally any one of an ES film, an AP film, a PP film, a PE film, and a paper film. This effect achieved by the present invention is advantageous compared to the prior art.

[0018] Referring to FIG. 2, it is shown that the nominal diameter D of the straw 1 is 4 mm, 6 mm, 8 mm, 10 mm, or 12 mm, but is not limited thereto.

[0019] According to one embodiment of the present invention, the base material 2 is made of fluorene-free paper, and this paper is food grade. Therefore, the paper straw of the present invention is harmless to the human body and is also beneficial to environmental protection. Further, the present invention is also applicable to straws made of plastic materials.

[0020] Referring to FIG. 3A, it is shown that the substrate 2 has a first surface 21 coated with a degradable coating 4. The degradable coating 4 has a third thickness t3 in the range of 0.014 mm to 0.020 mm, which corresponds to the weight of the degradable coating 4 in the range of 10 g / m2 to 15 g / m2. The degradable coating 4 is at least one of hydrolyzable and biodegradable. Also, the degradable coating 4 is either waterproof or non-waterproof, and preferably waterproof.

[0021] According to another embodiment of the present invention, as shown in FIG. 3B, the substrate 2 has a second surface 22 coated with a degradable coating 4.

[0022] Referring to FIG. 4, it is shown that the substrate 2 has a first short side 15 having a first width W1, the overlapping portion 3 has an overlapping width W2, and the ratio of the overlapping width W2 to the first width W1 is in the range of 0.051 to 0.131.

[0023] Referring to FIGS. 1C and 4, the substrate 2 has a zigzag-shaped first short side 15, and the first short side 15 consists of a first edge 151, a second edge 152, and a third edge 153. The first edge 151 has a first sub-length L1, and the second edge 152 has a second sub-length L2. The first edge 151 and the third edge 153 overlap to form an overlapping edge 30 of the overlapping portion 3. The first edge 151 and the second edge 152 have the same acute angle θ with respect to the longitudinal direction LD of the straw body 11. In order for the straw 1 to be easily pierced into the sealing film covering the portable paper cup, the acute angle θ is preferably in the range of 35° to 65°.

[0024] Referring to FIGS. 1C, 2, and 4, when looking at the overlapping edge 30, the first long side 13 may be on top of the second long side 12, or it is also applicable that the second long side 12 is on top of the first long side 13. The first sub-length L1 is equal to the second sub-length L2.

[0025] When forming the straw 1 by cutting the circular tube of the base material 2 to form an end portion 12 inclined with respect to the longitudinal direction LD of the straw body 11, a cutting error may be tolerated. As shown in FIG. 1C, this is the case where the first longitudinal side 31 coincides with the sharp point 16. According to another embodiment of the present invention, the first longitudinal side 31 is slightly displaced from the sharp point. Therefore, the first longitudinal side 31 is not on a straight line with the sharp point 16. It is a schematic diagram showing the planarized shape when the substrate according to another embodiment of the present invention is planarized, and also shows a partial enlarged view of the end portion of the straw. When there is a cutting error in the cutting, the planarized shape of the substrate is shown in FIG. 5, and the overlapping width W2 is composed of a third width W3 labeled near the first long side 13 and a fourth width W4 labeled near the second long side 14. Before forming the straw 1, the base material 2 is wound into a cylindrical shape and sealed to form a sealed scroll base material 2 having an overlapping portion 3. Therefore, the nominal diameter D of the straw 1 is the same, and the outer circumference of the straw 1 remains the same. Similarly, when the straw 1 is flattened and viewed from above, the overlapping width W2 is the value obtained by subtracting W4 from W3. In other words, when the first longitudinal side 31 is on a straight line with the sharp point 16, W4 is zero and W3 is equal to W2, but when the first longitudinal side 31 is displaced from the sharp point 16, W3 is equal to W2. On the other hand, when the first longitudinal side 31 is displaced from the sharp point 16, W3 is larger than W2, and the value of W4 is equal to the value obtained by subtracting W2 from W3. Due to the cutting deviation / tolerance, in the case of a substrate where the first width W1 is 43 mm, 29 mm or 23 mm, W4 is in the range of 0 to 1.0 mm. The physical meaning of W4 is, for example, the distance between the first longitudinal side 31 and a virtual straight line passing through the sharp point 16 and parallel to the longitudinal direction LD. Therefore, the displacement of the first longitudinal side 31 from the virtual straight line is in the range of 0 to 1.0 mm as the value of W4.

[0026] Figures 6A and 6B are schematic diagrams showing a cutting method for forming the straw 1 according to two different embodiments of the present invention. Referring to Figures 6A and 6B, two directions for cutting the sealed scroll substrate 2 are shown. The two cutting lines are along C1-C1 and C2-C2. The cutting line C1-C1 is inclined, and the cutting line C2-C2 is perpendicular to the longitudinal direction LD. The difference between Figures 6A and 6B is that after cutting the sealed scroll substrate 2, the end 12 of the obtained straw 1 is inclined upward or downward. As shown in Figure 6B, the sealed scroll substrate 2 is cut along two cutting lines C3-C3 and C2-C2.

[0027] Test results Straws having a paper substrate thickness of 0.265 mm and 0.295 mm and a degradable coating on both sides of the paper substrate were tested.

[0028] 1. Measurement of the thickness of the substrate thickness t1 and the overlapping part t2 [Table 1]

[0029] It was found that the ratio of the substrate thickness to the thickness of the overlapping part is about 1.4 to 1.8.

[0030] 2. Width of the overlapping part [Table 2]

[0031] It was found that the ratio of the width of the substrate to the width of the overlapping part is in the range of about 0.051 to 0.131.

[0032] 3. Puncture test of the sealing film of paper cups with different paper thicknesses [Table 3] Remarks: "O" means qualified, and "X" means failed.

[0033] The test straw of the present invention has been found to successfully penetrate all types of sealing films.

[0034] 4. Immersion test results of the sealing films of paper cups with different paper thicknesses The straw of the present invention was immersed in water at room temperature for testing. As a comparative example, straws from other manufacturers with the same thickness were also tested.

Table 4

[0035] It was found that the test straw of the present invention has excellent water resistance compared to the test straws of other manufacturers. According to the test results, the immersion time / duration during which the test straws with a thickness of 0.265 - 0.295 in Examples 1 - 3 of the present invention do not decompose is longer than 48 hours. On the other hand, for the test straws with a thickness of 0.25 mm - 0.34 mm in Comparative Examples 1 - 4, they are approximately 2 hours, approximately 4 hours, and approximately 8 hours respectively. Therefore, in the present invention, the immersion time / duration of the straws that are not decomposed is more than 24 times (calculated as 48 hours / 2 hours) and at least 6 times (calculated as 48 hours / 8 hours) longer than those of other manufacturers.

[0036] From the above, it can be seen that: First, for the straw according to the present invention, when heat-sealed, force and pressure are applied to the overlapping part of the straw, so the material density of the straw becomes smaller and the durability against liquids is high. The overlapping part is higher than the non-overlapping part of the base material. Second, for the straw according to the present invention, since the first longitudinal side 31 is on the same straight line as the sharp point 16, the strength of the sharp tip is high, and it can more easily pierce the sealing films such as ES film, AP film, PP film, PE film, and paper film in the portable paper cup. Third, for the straw according to the present invention, after the base material is scrolled and sealed and then cut into products, the manufacturing process of the straw of the present invention is much simpler than the manufacturing process of the straw of the prior art. Fourth, the paper straw according to the present invention is harmless to the human body and beneficial to environmental protection. Fifth, the paper straw according to the present invention does not contain a plastic coating, so the paper straw can be recycled to obtain pulp, and then the pulp can be reused to manufacture a new paper straw, thereby reducing the recycling cost of the paper material and the regeneration cost of the paper. The above effects are unexpected or cannot be achieved by the prior art.

[0037] Example 1. The straw has an end and includes a tubular straw body formed of a base material. The base material has a first long side, a second long side, and a first thickness. The first long side overlaps the second long side to form an overlapping part having a second thickness, and the ratio of the second thickness to the first thickness is less than 2. 2. In the straw of Example 1, the ratio is in the range of 1.43 to 1.8. 3. In the straws of Examples 1 to 2, the straw has a nominal diameter selected from the group consisting of 4 mm, 6 mm, 8 mm, 10 mm, and 12 mm, the base material is made of paper, and the paper is food grade. 4. In the straws of Examples 1 to 3, the base material has a first surface coated with a degradable coating, the degradable coating has a third thickness in the range of 0.014 mm to 0.020 mm, the degradable coating has at least one of hydrolyzability and biodegradability, and the degradable coating is waterproof and aqueous. 5. In the straws of Examples 1 to 4, the overlapping portion is sealed by heating the degradable coating using ultrasonic waves, and the base material has a second surface coated with the degradable coating. 6. In the straws of Examples 1 to 5, the base material has a first short side having a first width, the overlapping portion has an overlapping width, and the ratio of the overlapping width to the first width (W1) of the straw is in the range of 0.051 to 0.131. 7. In the straws of Examples 1 to 6, the base material has a zigzag-shaped first short side, the first short side consists of a first edge having a first sub-length, a second edge having a second sub-length, and a third edge, the first edge overlaps with the third edge to form an overlapping edge of the overlapping portion, the first sub-length is equal to the second sub-length, the first edge and the second edge have the same acute angle with respect to the longitudinal direction of the tubular straw body, and the range of the same acute angle is 35° to 65°. 8. In the straws of Examples 1 to 7, the overlapping portion has two linear longitudinal side surfaces, the material density of the overlapping portion is greater than the material density of the non-overlapping portion of the base material, and the non-overlapping portion has the first thickness. 9. In the straws of Examples 1 to 8, the end portion of the tubular straw body is an inclined end portion having a sharp tip, one of the two longitudinal sides is on a straight line with the sharp tip, and the distance between one of the two longitudinal sides and a virtual straight line passing through the sharp point and parallel to the longitudinal direction of the tubular straw body is in the range of 0 to 1.0 mm.

[0038] As described above, the present invention has been explained using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. It is clear from the description of the claims that forms with such changes or improvements can also be included in the technical scope of the present invention.

Explanation of Signs

[0039] 1: Straw 2: Substrate 3: Overlap portion 4: Degradable coating 5: Non - overlap portion 11: Straw body 12: End 13: First long side 14: Second long side 15: First short side 16: Sharp point / tip 21: First surface 22: Second surface 30: Overlap edge 31, 32: Longitudinal side 151: First edge 152: Second edge 153: Third edge D: Nominal diameter LD: Longitudinal direction L1: First sub - length L2: Second sub - length W1: First width W2: Overlap width W3: Third width t1: First thickness t2: Second thickness t3: Third thickness

Claims

1. A straw comprising a tubular straw body having an end and formed of a base material, wherein the base material has a first long side, a second long side, and a first thickness, the first long side overlaps the second long side to form an overlapping portion having a second thickness, and a ratio of the second thickness to the first thickness is less than 2.

2. The straw according to claim 1, wherein the ratio is in a range of 1.43 to 1.

8.

3. The straw has a nominal diameter selected from the group consisting of 4 mm, 6 mm, 8 mm, 10 mm, and 12 mm, and the base material is made of paper, and the paper is food grade.

4. The base material has a first surface coated with a degradable coating, the degradable coating has a third thickness in a range of 0.014 mm to 0.020 mm, the degradable coating has at least one of hydrolyzability and biodegradability, and the degradable coating is waterproof and aqueous.

5. The overlapping portion is sealed by heating the degradable coating using ultrasonic waves, and the base material has a second surface coated with the degradable coating.

6. The base material has a first short side having a first width, the overlapping portion has an overlapping width, and a ratio of the overlapping width to the first width (W1) of the straw is in a range of 0.051 to 0.

131.

7. The base material has a first short side in a zigzag shape, the first short side consists of a first edge having a first sub-length, a second edge having a second sub-length, and a third edge, the first edge overlaps the third edge to form an overlapping edge of the overlapping portion, the first sub-length is equal to the second sub-length, the first edge and the second edge have the same acute angle with respect to the longitudinal direction of the tubular straw body, and a range of the same acute angle is 35° to 65°.

8. The overlapping portion has two linear longitudinal side surfaces, a material density of the overlapping portion is greater than a material density of a non-overlapping portion of the base material, and the non-overlapping portion has the first thickness.

9. The end portion of the tubular straw body is an inclined end portion, having a sharp tip, and one of the two longitudinal sides is in a straight line with the sharp tip. The straw according to claim 8, wherein the distance between one of the two longitudinal sides and a virtual straight line passing through the sharp point and parallel to the longitudinal direction of the tubular straw body is in the range of 0 to 1.0 mm.

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