Straw and preparation method therefor

Abstract

A straw and a preparation method therefor. The straw comprises: at least one bamboo strip layer (1), the bamboo strip layer (1) being a first tube body formed by winding a bamboo strip (3), and the bamboo strip (3) being machined from raw bamboo; and at least one paper strip layer (2), the paper strip layer (2) comprising a paper strip (4), and the paper strip (4) being attached to at least part of the surface of the first tube body. The preparation method comprises: a bamboo strip layer (1) forming step, which comprises helically winding a bamboo strip to form the bamboo strip layer (1); and a paper strip layer (2) forming step, which comprises helically winding a paper strip (4) to form the paper strip layer (2). The bamboo strip layer (1) is formed by means of winding the bamboo strip (3), and serves as a structural support layer of the straw, thereby solving the problem of paper straws softening easily; moreover, the paper strip layer (2) is attached to the bamboo strip layer (1), and the bamboo strip layer (1) is reinforced by using the toughness of the paper strip (4) itself, thereby solving the problem of the poor tensile and torsional resistance of bamboo straws; in addition, compared with pure bamboo straws, the amount of the bamboo strip (3) used in the bamboo-paper straw is reduced, and the paper strip (4) is attached to the bamboo strip (3), such that the manufacturing difficulty is reduced, and the production cost is saved.

Description

A straw and a preparation method thereof Technical Field

[0001] The present invention relates to the technical field of straw processing, in particular to a straw and a preparation method thereof. Background Art

[0002] As plastic pollution becomes increasingly serious, plastic waste has caused irreparable damage to the Earth's ecology. Disposable plastic straws, a frequently used item in daily life, are generating waste that exacerbates environmental pollution. Consequently, many countries and regions have begun to impose restrictions on, or even ban, traditional plastic straws.

[0003] Against this backdrop, market demand for environmentally friendly, biodegradable straw products is growing. Because PLA (polylactic acid) is made from biomaterials and offers the advantage of biodegradability, PLA straws have gradually been pushed to the forefront of the market, quickly becoming an alternative to plastic straws. However, with the use of PLA straws, their shortcomings have gradually become apparent. First, their degradation process is not as rapid as marketed, requiring specific conditions and time, which causes them to persist for long periods in many environments and remain undegradable. Second, PLA has poor heat and water resistance. When soaked in hot drinks or liquids for extended periods, PLA straws will deform and soften, severely impacting the user experience.

[0004] To meet market demand, pure paper straws emerged. Paper is naturally biodegradable and environmentally friendly, making it the primary material for straws. However, it also has a significant drawback: if soaked in liquid for a prolonged period, paper straws will soften, reducing the user experience.

[0005] On the other hand, bamboo, as a material with fast regeneration and biodegradability, is gradually being used in the manufacture of straws. For example, Chinese Patent ZL202110538234.1 discloses a production process for wound bamboo straws. However, due to the characteristics of bamboo, its toughness is relatively poor. Without chemical treatment, production and processing require careful control to reduce the scrap rate in the manufacturing process. At the same time, the winding production method requires control over the tensile strength and torsional resistance of pure bamboo straws, otherwise they are prone to cracking during use. Technical issues

[0006] The technical problems to be solved by the present invention include at least how to improve the tensile strength and / or torsional resistance of bamboo straws to avoid cracking during use. Technical Solutions

[0007] To address the above technical issues, the present invention creatively introduces paper with higher tensile strength, combining bamboo and paper to develop a composite straw. This straw not only ensures structural stability and user experience, but also ensures environmental friendliness and biodegradability. The specific technical solutions adopted are as follows:

[0008] A straw, comprising:

[0009] At least one bamboo tape layer, wherein the bamboo tape layer is a first tube formed by winding bamboo tapes; the bamboo tapes are machine-processed from raw bamboo;

[0010] At least one paper tape layer, the paper tape layer comprising paper tape, the paper tape being attached to at least a portion of the surface of the first tube.

[0011] In order to solve the above technical problems, another technical solution adopted by the present invention is:

[0012] A method for preparing a straw, comprising:

[0013] The bamboo tape layer forming step comprises winding the bamboo tape into the bamboo tape layer; the bamboo tape is formed by mechanical processing of the original bamboo;

[0014] and, a paper tape layer forming step of winding the paper tape to form the paper tape layer;

[0015] The paper tape is attached to at least a portion of the surface of the bamboo tape layer. Beneficial effects

[0016] The beneficial effects of the present invention are: providing a straw and a preparation method thereof, by mechanically processing the original bamboo into bamboo tapes, and winding the bamboo tapes to form a bamboo tape layer as the structural support layer of the straw, thereby solving the problem that paper straws are easy to soften; at the same time, a paper tape layer is attached to the bamboo tape layer, and the toughness of the paper tape itself is used to strengthen the bamboo tape layer, thereby solving the problem of poor tensile and torsional properties of the bamboo straws; in addition, the bamboo paper straws disclosed in the present invention reduce the amount of bamboo tape used in the straws compared to pure bamboo straws, and use paper tapes and bamboo tapes to attach, which reduces the manufacturing difficulty, and the finished product rate reaches more than 99%, saving production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIG1 is a schematic diagram of a straw according to a first embodiment of the present invention;

[0018] FIG2 is a schematic diagram of another straw according to Example 1 of the present invention;

[0019] FIG3 is a schematic diagram of a straw according to a second embodiment of the present invention;

[0020] FIG4 is a cross-sectional view of a straw in FIG3 ;

[0021] Description of labels:

[0022] 1. Bamboo tape layer; 2. Paper tape layer; 3. Bamboo tape; 4. Paper tape. Modes for Carrying Out the Invention

[0023] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and accompanying drawings.

[0024] 1 to 4 , the present invention discloses a straw comprising a first tube body formed of a bamboo strip and a second tube body formed of a paper strip, wherein the first tube body and the second tube body are attached to each other.

[0025] In some embodiments, the attachment arrangement may specifically be a glue layer provided between the first tube body and the second tube body.

[0026] It should be noted that the first tubular body can be formed from a tightly continuous bamboo strip, or a sparse bamboo strip or a sparsely spaced bamboo strip. Similarly, the second tubular body can be formed from a tightly continuous paper strip, or a sparsely spaced, stacked, or sparsely spaced paper strip. Those skilled in the art will appreciate that when the first and second tubular bodies are combined to form a straw, the straw as a whole provides a flow channel for fluid circulation.

[0027] In certain embodiments, a straw is provided, comprising at least one bamboo tape layer, the bamboo tape forming a first tube; at least one paper tape layer, the paper tape forming a second tube; and an adhesive layer disposed between the first and second tubes. The tubes can be formed by winding, specifically, the bamboo tape can be wound to form the first tube, and the paper tape can be wound to form the second tube.

[0028] The present invention further discloses a straw, comprising:

[0029] At least one bamboo belt layer 1, wherein the bamboo belt layer 1 is a tube formed by winding bamboo belts 3; the bamboo belts 3 are made of raw bamboo through mechanical processing;

[0030] At least one paper tape layer 2 , wherein the paper tape layer 2 includes a paper tape 4 , and the paper tape 4 is attached to at least a portion of the surface of the bamboo tape layer 1 .

[0031] The winding forms include spiral winding, horizontal winding and cross winding, etc. The specific winding method is selected according to the production conditions and the expected effect.

[0032] Based on general cognition, raw bamboo refers to bamboo grown in nature, rather than bamboo fiber extracted through multiple chemical process steps. Since raw bamboo itself is hydrophobic, the bamboo tape formed after cutting the raw bamboo is more durable than the composite materials made of pulp or bamboo fiber slurry. Generally speaking, raw bamboo cutting includes a variety of processing methods. For example, in an embodiment of the present invention, after the raw bamboo segment is cut into bamboo chips, mechanical processing is performed along the fiber direction of the bamboo chips to form a bamboo tape. It should be noted that, according to common understanding, the shape of the bamboo tape refers to a long strip of object whose length is much greater than its width and thickness. For example, the size of the bamboo tape can be 1-400m in length, 10-20mm in width, and 0.25-1mm in thickness. Preferably, the bamboo tape can be 300m in length, 15mm in width, and 0.25mm in thickness.

[0033] The paper tape is attached to a portion of the surface of the bamboo tape layer, i.e., the connection between the paper tape and the bamboo tape layer is tight and fixed; specifically, the attachment includes but is not limited to internal gluing and external sealing. It should be noted that the so-called paper tape is generally made from raw wood pulp that has been surface-treated and then processed and cut. In the field of paper straws, for example, the paper tape is made by modifying raw wood pulp into kraft paper and then slitting it.

[0034] The bamboo strip at least comprises: a strip formed by cutting from one end of a bamboo piece to the other end along the fiber direction of the bamboo. The thickness of the bamboo strip in the embodiment of the present invention ranges from 0.25 mm to 0.5 mm.

[0035] The paper tape at least comprises a strip formed by cutting kraft paper, food-grade coated paper or reinforced paper. Furthermore, in some embodiments of the present invention, the thickness of the paper tape ranges from 60 to 220 g / cm. 2 .

[0036] From the above description, it can be seen that the beneficial effects of the present invention are: by mechanically processing the original bamboo into bamboo strips, and winding the bamboo strips 3 to form a bamboo strip layer 1 as the structural support layer of the straw, the problem of easy softening of paper straws is solved; at the same time, a paper strip layer 2 is attached to the bamboo strip layer 1, and the toughness of the paper strip 4 itself is used to strengthen the bamboo strip layer 1, thereby solving the problem of poor tensile and torsional properties of bamboo straws; in addition, the bamboo paper straws disclosed in the present invention reduce the amount of bamboo strips 3 used in the straws compared to pure bamboo straws, and use paper strips 4 to attach to the bamboo strips 3 to reduce the manufacturing difficulty, and the finished product rate reaches more than 99%, saving production costs.

[0037] In some embodiments of the present invention, the paper tape layer 2 is a second tube formed by winding the paper tape 4 .

[0038] From the above description, it can be seen that in order to strengthen the overall strength of the straw, the paper tape layer 2 and the bamboo tape layer 1 are both wound and formed, and the wound paper tape layer 2 is attached to the bamboo tape layer 1. The winding form allows the paper tape layer to be dispersed between the winding layers when subjected to torsion, reducing the negative effects of stress concentration, thereby improving the torsional resistance of the straw. Specifically, the winding body of the paper tape itself forms a radial constraint on the winding body of the bamboo tape, reducing the torsion that the bamboo tape bears due to bending. During the research and development process, the inventors found that the analysis of scrapped products of all-bamboo straws, especially bamboo tape straws directly processed from raw bamboo, often resorts to visual defects in the bamboo tape processing process. The inventors found that under special circumstances, in the absence of obvious visual defects, the bamboo tape still faces a certain probability of failure risk during the winding process or after the finished product. Studies have shown that micro-cracks may form during the processing of bamboo tape, leading to stress concentration and forming potential cracking points. These will not manifest as cracks or fractures in the early stages of winding. This stress concentration may only appear after the finished product is manufactured, during storage and transportation, and during use. For such situations where the product is qualified but deteriorates later, producers often have no way of discovering and responding. Based on the discovery and tracing of this problem, the inventors introduced a paper tape layer into the bamboo straw structure in the form of a winding, which successfully and effectively reduced the tensile stress along the grain of the bamboo tape, effectively reduced stress concentration, and thus reduced the risks of cracking and fracture, reduced the risk of straw failure, and improved the yield rate of straws.

[0039] In some embodiments of the present invention, adjacent winding layers of the paper tape 4 are overlapped.

[0040] As can be seen from the above description, in order to reduce the manufacturing difficulty and considering the relatively soft texture of the paper tape 4, the paper tape layer 2 is generated by stacking adjacent layers of paper tape 4. At the same time, the paper tape layer 2 with adjacent layers stacked layer by layer has better waterproof performance than the joint structure. In addition, the layers of paper tape are stacked on each other, and the stacked layers provide constraints to the stacked layers. During the paper tape winding process, the stacked layers generate self-tightening force under the constraints of the stacked layers, thereby strengthening the entire paper tape layer. Experiments have shown that compared with non-stacked paper tape layers, the stacked layers of paper tape have better torsion resistance after being attached to the bamboo tape layer to form a straw. Preferably, the thickness of the stacked layers of paper tape is in the range of 1mm-3mm.

[0041] In an embodiment of the present invention, the size of the overlapping thickness is positively correlated with the size of the spiral angle of the paper tape winding; specifically, in order to avoid excessive paper tape winding seams that lead to overlap with the bamboo tape layer seams during the production process, the spiral angle of the paper tape layer tends to be controlled within a larger range. However, during the spiral winding process, under the condition that the paper tape width is fixed, the larger the spiral angle, the smaller the overlapping thickness of the paper tape. At this time, the gram weight of the paper tape per unit area is low, and the strengthening effect on the bamboo tape layer is poor. In order to solve this problem, when the spiral angle of the paper tape winding tends to increase, in order to ensure the gram weight of the paper tape per unit area, it is necessary to increase the overlapping thickness between the paper tape layers by increasing the paper tape width, that is, the size of the overlapping thickness of the paper tape is positively correlated with the size of the spiral angle of the paper tape winding.

[0042] In certain embodiments of the present invention, experiments have shown that, in some cases, the stacking thickness and the helix angle may need to be adaptively adjusted based on the technical requirements for the inner or outer diameter of the straw. Preferred parameters include at least: an inner diameter of 5 mm to 12 mm, an outer diameter of 6 mm to 13 mm, a stacking thickness of 1 mm to 3 mm, and a helix angle of 35° to 55°.

[0043] In some embodiments of the present invention, the bamboo tape 3 and the paper tape 4 are wound in the same direction.

[0044] As can be seen from the above description, in order to ensure that the seams of the bamboo tape 3 and the paper tape 4 caused by winding can cover each other and avoid excessive interlacing of the seams, the bamboo tape 3 and the paper tape 4 of the straw in the embodiment of the present invention have the same rotation direction.

[0045] In some embodiments of the present invention, the bamboo tape 3 and the paper tape 4 are wound in opposite directions.

[0046] As can be seen from the above description, to enhance the straw's tensile and torsional resistance, the bamboo tape 3 and paper tape 4 are rotated in opposite directions. When subjected to torsional forces, the bamboo tape layers 1 and paper tape layers 2, with opposite rotations, provide a restraining force against each other, preventing deformation. Specifically, when the straw in this embodiment of the present invention is subjected to torsional forces, one of the paper and bamboo tape layers with opposite rotations will inevitably have an acute angle between its rotation and the torsional force. The torsional force then strengthens the winding of this layer, creating a self-tightening effect under the torsional force, thereby absorbing the torsional force and limiting the possibility of cracking in the other layer due to twisting.

[0047] In some embodiments of the present invention, the helical angle of the bamboo tape 3 is smaller than the helical angle of the paper tape 4 .

[0048] As can be seen from the above description, to reduce seams in the paper tape 4, the helical angle of the bamboo tape layer 1 in this embodiment is smaller than that of the paper tape layer 2. That is, when winding straws of the same height, because the helical angle of the bamboo tape 3 is smaller than that of the paper tape 4, the number of coils of the paper tape 3 is smaller than that of the bamboo tape 3. This reduces the number of seams created when the paper tape 4 is wound, thereby improving the straw's waterproof performance. In certain embodiments of the present invention, the paper tape layer 2 includes at least one paper tape 4 attached to at least a portion of the inner surface of the bamboo tape layer 1. Specifically, the helical angle of the bamboo tape is between 30° and 45°, and the helical angle of the paper tape is between 46° and 70°. Preferably, the helical angle of the bamboo tape is between 35° and 40°, or between 40° and 45°, and the helical angle of the paper tape is between 50° and 60°, or between 60° and 70°. More preferably, the helical angle of the bamboo tape is 38°, 40°, 42°, or 45°, and the helical angle of the paper tape is 50°, 55°, 60°, or 65°. Studies have found that when the helical angle of the paper tape is 55°, the optimal helical angle of the bamboo tape is 40°; when the helical angle of the bamboo tape is 45°, the optimal helical angle of the paper tape is 65°. In certain embodiments of the present invention, the paper tape layer 2 further includes at least one paper tape 4 attached to at least a portion of the outer surface of the bamboo tape layer 1.

[0049] In some embodiments of the present invention, the paper tape layer 2 further includes at least one paper tape 4 attached to at least a portion of the outer surface of the first tube.

[0050] From the above description, it can be seen that in an embodiment of the present invention, as shown in Figure 1, the paper tape layer 2 is located on the inner surface of the bamboo tape layer 1, that is, the bamboo tape layer 1 is on the outside, and the paper tape layer 2 is attached to the bamboo tape layer 1 on the inside, thereby improving the tensile and torsional properties of the bamboo tape layer 1 on the inside of the bamboo tape layer 1; at the same time, the bamboo tape layer 1 located on the outside provides a protective effect for the paper tape layer 2 located on the inside, thereby preventing the paper tape layer from being damaged by the outside.

[0051] Alternatively, as shown in FIG2 , in an embodiment of the present invention, the paper tape layer 2 is located on the outer surface of the first tube, that is, the bamboo tape layer 1 is on the inner side, and the paper tape layer 2 is attached to the bamboo tape layer 1 on the outer side to improve the tensile and torsional properties of the bamboo tape layer 1; at the same time, the paper tape layer 2 located on the outer side also absorbs burrs on the surface of the bamboo tape layer 1, thereby improving user experience;

[0052] Or, as shown in Figure 3, in an embodiment of the present invention, the paper tape layer 2 is attached to the inner and outer sides of the first tube body, that is, the paper tape layer 2 is attached to the inner and outer sides of the bamboo tape 3, respectively, to strengthen the bamboo tape layer 1 on both sides and absorb the burrs on the surface of the bamboo tape layer 1.

[0053] In some embodiments of the present invention, the width of the bamboo tape 3 or the paper tape 4 located in the inner layer is smaller than the width of the bamboo tape 3 or the paper tape 4 located in the outer layer.

[0054] From the above description, it can be seen that the width of the bamboo tape 3 or paper tape 4 used for the bamboo tape layer 1 or the paper tape layer 2 is increased from the inside to the outside, that is, the number of seams in the outer layer is less than the number of seams in the inner layer. During the production process, the seams generated when the bamboo tape 3 or paper tape 4 in the outer layer is wound are more likely to avoid the seams in the inner layer, reducing the difficulty of production; at the same time, the outer seams are reduced, and the sealing performance of the straw is improved. Specifically, studies have shown that during the winding process of each layer of the straw, the number of superimposed seams between each level is negatively correlated with the torsional resistance of the straw, that is, the more superimposed seams between each level in the straw, the worse the torsional resistance of the straw. The inventor controls the width of the wound paper tape or bamboo tape to increase layer by layer from the inside to the outside, effectively reducing the number of superimposed seams in the straw, reducing the risk of straw failure, and improving the durability of the straw.

[0055] Specifically, the width of the outer paper or bamboo tape is 1.05-1.3 times, and preferably 1.15 times, the width of the inner paper or bamboo tape. The width of the inner bamboo tape is 20mm-29mm, while the width of the inner paper tape is 15mm-30mm.

[0056] In some embodiments of the present invention, an adhesive layer is provided between the bamboo tape layer 1 and the paper tape layer 2 .

[0057] Specifically, the adhesive layer between the paper tape and the bamboo tape includes but is not limited to food-grade PVA (polyvinyl alcohol) glue, food-grade chitosan, food-grade starch glue or food-grade latex, and the adhesive layer coating amount ranges from 10g / m 2 -30 g / m 2 .

[0058] In some embodiments of the present invention, the opposing surfaces of the bamboo tape layer 1 and the paper tape layer 2 are respectively provided with adhesive layers.

[0059] From the above description, it can be seen that a glue layer is provided between the bamboo tape layer 1 and the paper tape layer 2, that is, the bamboo tape layer 1 and the paper tape layer 2 are attached by gluing; specifically, in this embodiment, glue layers are respectively provided on the opposite surfaces of the bamboo tape layer 1 and the paper tape layer 2 to improve the attachment effect.

[0060] Specifically, in the embodiment of the present invention, when both surfaces of the paper tape layer and the bamboo tape layer are provided with adhesive layers, the coating amount of the adhesive layer of the paper tape layer is in the range of 10 g / m 2 -20 g / m 2 ; The coating amount of the bamboo tape layer is in the range of 20g / m 2 -40 g / m 2 .

[0061] In some embodiments of the present invention, adjacent coils of the bamboo strip 3 are joined.

[0062] From the above description, it can be seen that since the bamboo tape in the present invention is processed from raw bamboo and is not a composite material containing bamboo fiber, in order to improve the forming rate of the bamboo tape layer 1, the adjacent coils of the bamboo tape 3 are joined, that is, the adjacent coils of the bamboo tape 3 are not overlapped and fit tightly to avoid damage to the bamboo tape due to overlapping; at the same time, the coils are joined to each other, and the surface of the manufactured bamboo tape layer 1 is smooth and has no protruding structure, so as to avoid gaps after the paper tape layer 2 is attached.

[0063] A method for preparing a straw, comprising:

[0064] The bamboo strip layer 1 forming step comprises winding the bamboo strips 3 into the bamboo strip layer 1; the bamboo strips 3 are made of raw bamboo through mechanical processing;

[0065] and, a paper tape layer 2 forming step of winding the paper tape 4 to form the paper tape layer 2;

[0066] The paper tape is attached to at least a portion of the surface of the bamboo tape layer.

[0067] As can be seen from the above description, a method for preparing a straw is provided, comprising forming a bamboo tape layer 1 and a paper tape layer 2. The bamboo tape layer is then reinforced with paper tape to increase its toughness during production and use, thereby reducing the risk of cracking. Specifically, winding methods include spiral winding, horizontal winding, and cross winding, with the specific winding method selected based on production conditions and desired results; spiral winding is preferred.

[0068] The bamboo strip at least comprises: a strip formed by mechanically processing from one end of a bamboo piece to the other end along the fiber direction of the bamboo. The thickness of the bamboo strip in the embodiment of the present invention ranges from 0.25 mm to 0.5 mm.

[0069] The paper tape at least comprises a strip formed by cutting kraft paper, food-grade coated paper or reinforced paper. The thickness of the paper tape in the embodiment of the present invention is in the range of 30-220g / cm 2 .

[0070] In some embodiments of the present invention, the steps of forming the bamboo tape layer 1 are specifically as follows: spirally winding the bamboo tape 3 to form a single-layer bamboo tube;

[0071] The step of forming the paper tape layer 2 is specifically as follows: tightly winding the paper tape 4 around the outer surface of the single-layer bamboo tube to form a composite layer.

[0072] From the above description, it can be seen that during the preparation process, the bamboo tape 3 is first wound into a single-layer bamboo tube as a base layer to provide good support for the subsequent winding of the paper tape 4, thereby preventing the paper tape layer from collapsing during the winding process; at the same time, the paper tape 4 has strong toughness, and friction is used to compress and strengthen the bamboo tape layer during winding.

[0073] In some embodiments of the present invention, the step of forming the paper tape layer 2 is specifically as follows: spirally winding the paper tape 4 to form a single-layer paper roll;

[0074] The specific step of forming the bamboo tape layer 1 is: tightly winding the bamboo tape 3 around the outer surface of the single-layer paper tube to form a composite layer.

[0075] As can be seen from the above description, since the tension and toughness of the paper tape 4 are stronger than those of the bamboo tape 3, it is easier to control during the winding process than the bamboo tape 3. In order to reduce the difficulty of preparation, the paper tape 4 is first wound into a single-layer paper tube as the inner layer to provide a good adhesion surface for the subsequent winding of the bamboo tape 3, thereby avoiding slipping or inaccurate positioning of the bamboo tape 3 during winding. Specifically, the bamboo tape cut from raw bamboo in the present invention is polished before processing to improve the smoothness of the bamboo tape surface. However, in the actual production process, the inventors found that due to the smooth surface of the bamboo tape, it is easy to slip or misalign with the winding shaft of the winding equipment during winding. Based on the discovery and tracing of this problem, the inventors wound the paper tape before the bamboo tape, using the capillary structure on the paper tape to provide a certain degree of roughness, thereby preventing inaccurate positioning of the bamboo tape during winding, thereby improving the yield of the straws.

[0076] Furthermore, the steps include:

[0077] The paper tape 4 is tightly wound around the outer surface of the composite layer.

[0078] From the above description, it can be seen that on the basis of the paper tape layer 2 as the base layer and the bamboo tape layer 1 as the covering layer, the paper tape layer 2 is wound again on the outer surface of the bamboo tape layer 1 to compact and strengthen the bamboo tape layer 1; at the same time, the burrs on the surface of the bamboo tape layer 1 are absorbed to improve the user experience.

[0079] In some embodiments of the present invention, adjacent spirally wound coils of the paper tape 4 are overlapped.

[0080] From the above description, it can be seen that in order to enhance the overall strength of the straw, the paper tape layer 2 and the bamboo tape layer 1 are both rolled into shape. Compared with directly attaching paper, the rolled paper tape layer 2 attached to the bamboo tape layer 1 has better torsional resistance from the perspective of force.

[0081] In some embodiments of the present invention, adjacent spirally wound layers of the bamboo strip 3 are joined.

[0082] From the above description, it can be seen that during the manufacturing process, in order to improve the forming rate of the bamboo tape layer 1, the adjacent coils of the bamboo tape 3 are joined, that is, the adjacent coils of the bamboo tape 3 are not overlapped and are tightly fitted; at the same time, the coils are joined to each other, and the surface of the manufactured bamboo tape layer 1 is smooth and has no protruding structure, so as to avoid gaps after the paper tape layer 2 is attached.

[0083] In some embodiments of the present invention, the step of forming a glue layer is further included:

[0084] Before winding, glue is applied on the opposite sides of the paper tape 4 and the bamboo tape 3;

[0085] Or the opposite surfaces to which the paper tape 4 and the bamboo tape 3 are attached are glued respectively.

[0086] As can be seen from the above description, in order to enhance the adhesion strength between the paper tape layer 2 and the bamboo tape layer 1, before winding, the opposite surfaces of the paper tape 4 and the bamboo tape 3 are glued on one side to form a glue layer; alternatively, before winding, the opposite surfaces of the paper tape 4 and the bamboo tape 3 are both glued, that is, the paper tape 4 is glued and the bamboo tape 3 is also glued, thereby forming a stable glue layer. Specifically, during the winding process, both the paper tape and the bamboo tape need to absorb the momentum caused by the start or stop of the winding device, that is, acceleration inevitably occurs during the winding process. At this time, since the glue layer is in liquid state, some flow will occur under the action of acceleration, resulting in uneven glue layer or a small amount of overflow. To solve this problem, the inventors chose to glue separately on the opposite surfaces of the paper tape and the bamboo tape. The principle is that the paper tape is relatively dense and has a stronger adsorption force on the glue layer than the bamboo tape. The fluidity of the glue layer during the winding process is relatively low, which reduces the loss of the glue layer. Under this gluing method, the glue amount of the paper tape is in the range of 20g / m 2 -30 g / m 2 Another form in this example is that before the bamboo tape is wound, glue is also applied on the surface opposite to the paper tape. The purpose is to allow the glue to penetrate into the gaps between the coils of the bamboo tape layer, which can greatly improve the stability of the bamboo tape winding during the production process. The inventor found in the research and development process that when a bamboo tape is wound, the bamboo tape layer that has been wound is prone to shrinkage that is difficult to detect with the naked eye due to the resilience of the bamboo fiber itself, which causes the shape of the straw itself to be distorted when the paper tape is subsequently wound. In order to solve this problem, it is chosen to apply glue before the bamboo tape layer is wound to improve the stability of the bamboo tape layer during the production process. Under this gluing method, the amount of glue applied to the bamboo tape is in the range of 20g / m 2 -40 g / m 2 , the glue amount of paper tape is in the range of 10g / m 2 -20 g / m 2 In certain embodiments of the present invention, the spiral angle of the paper tape 4 is greater than the spiral angle of the bamboo tape 3.

[0087] In some embodiments of the present invention, the spiral angle of the bamboo tape 3 is in the range of 30°-45°, and the spiral angle of the paper tape 4 is in the range of 46°-70°; specifically, the spiral angle of the bamboo tape is in the range of 30°-45°, and the spiral angle of the paper tape is in the range of 46°-70°; preferably, the spiral angle of the bamboo tape is in the range of 35°-40° or 40°-45°, and the spiral angle of the paper tape is in the range of 50°-60° or 60°-70°; more preferably, the spiral angle of the bamboo tape is 38°, 40°, 42° or 45°, and the spiral angle of the paper tape is 50°, 55°, 60° or 65°; research has found that when the spiral angle of the paper tape is 55°, the optimal spiral angle of the bamboo tape is 40°; when the spiral angle of the bamboo tape is 45°, the optimal spiral angle of the paper tape is 65°. From the above description, it can be seen that in order to reduce the seams of the paper tape 4, the spiral angle of the bamboo tape layer 1 is controlled to be smaller than the spiral angle of the paper tape layer 2 during the manufacturing process. The spiral angle is larger relative to the paper tape layer 2, and the number of seams is less than that of the bamboo tape layer 1; at the same time, the spiral angle of the paper tape 4 is different from the spiral angle of the bamboo tape 3, so as to avoid the overlap of the seams of the bamboo tape layer 1 and the paper tape layer 2, which affects the waterproof and torsional performance of the straw.

[0088] In some embodiments of the present invention, before the bamboo tape layer 1 is formed, the following steps are further included:

[0089] Glue the bamboo strip 3 to the composite paper.

[0090] As can be seen from the above description, in order to enhance the transverse tensile strength of the bamboo strip 3 during the winding process, the composite paper is glued to the bamboo strip 3 before winding. After the bamboo strip 3 is wound into the bamboo strip layer 1, the composite paper and the paper strip layer 2 are glued and attached to each other. Specifically, during the bamboo strip winding process, the winding device operates to wind the bamboo strip from a strip shape to a cylindrical shape. This inevitably transfers momentum to the bamboo strip. Since the bamboo strip is inherently brittle and hard, it is easily damaged by the sudden large momentum from a static state. However, some of this damage cannot be directly reflected in the macroscopic production process. It only causes cracking of the bamboo strip layer during subsequent storage, transportation, and use. Based on the discovery and tracing of this problem, the inventors first glued the bamboo strip with the composite paper before winding to enhance the toughness of the bamboo strip during winding. This successfully absorbs the momentum transmitted when the mechanical device is started, thereby reducing the risk of cracking and breakage, reducing the risk of straw failure, and improving the yield rate of straws.

[0091] The present invention discloses a straw and a preparation method thereof, which are mainly applied to the field of disposable straws and provide a naturally degradable and durable straw, which will be specifically described below with reference to embodiments.

[0092] Example 1

[0093] Referring to FIG. 1 or FIG. 2 , a straw includes:

[0094] A bamboo strip layer 1, which is a first tube formed by winding bamboo strips 3, which are machined from raw bamboo; serves as the structural support layer of the straw to solve the problem of paper straws being easily softened;

[0095] A paper tape layer 2 includes a paper tape 4, which is attached to at least part of the surface of the bamboo tape layer 1. The toughness of the paper tape 4 is used to strengthen the bamboo tape layer 1, thereby solving the problem of poor tensile and torsional resistance of the bamboo straw.

[0096] At the same time, compared with pure bamboo straws, the present embodiment reduces the amount of bamboo tape 3 used in the straws, and adopts paper tape 4 to attach to the bamboo tape 3, which reduces the manufacturing difficulty, achieves a finished product rate of more than 99%, and saves production costs.

[0097] Specifically, the bamboo tape layer 1 is formed by spiral winding;

[0098] As shown in Figure 1, in this example, the straw has a structure in which the paper tape layer 2 includes a paper tape 4 attached to at least a portion of the inner surface of the bamboo tape layer 1. Specifically, the bamboo tape layer 1 is on the outside, and the paper tape layer 2 is attached to the inside of the bamboo tape layer 1 to improve the tensile and torsional resistance of the bamboo tape layer 1.

[0099] As shown in Figure 2, another straw structure in this example is: the paper tape layer 2 includes a paper tape 4 attached to at least part of the outer surface of the bamboo tape layer 1. Specifically, the bamboo tape layer 1 is on the inside, and the paper tape layer 2 is attached to the outside of the bamboo tape layer 1 to improve the bamboo tape layer 1's tensile and torsional resistance. The outer paper tape layer 2 also absorbs burrs on the bamboo tape layer 1, improving the user experience.

[0100] Example 2

[0101] As shown in FIG3 and FIG4 , the difference between this embodiment and the first embodiment is that:

[0102] In addition to the paper tape layer comprising a paper tape 4 attached to at least a portion of the inner surface of the bamboo tape layer 1, the paper tape layer 2 further comprises at least one paper tape 4 attached to at least a portion of the outer surface of the bamboo tape layer 1. That is, the paper tape layer 2 is attached to both the inside and outside of the bamboo tape 3, strengthening the bamboo tape layer 1 on both sides and absorbing burrs on the surface of the bamboo tape layer 1.

[0103] Example 3

[0104] Based on the first embodiment, adjacent coils of the bamboo tape 3 are joined. Specifically, to improve the forming efficiency of the bamboo tape layer 1, adjacent coils of the bamboo tape 3 are joined, i.e., adjacent coils of the bamboo tape 3 do not overlap but fit tightly together. Furthermore, the coils are joined together, resulting in a smooth surface with no protrusions on the bamboo tape layer 1, thus preventing gaps from forming after the paper tape layer 2 is attached.

[0105] Example 4

[0106] Based on Example 1, the paper tape layer 2 is a tube formed by winding a paper tape 4. To enhance the overall strength of the straw, the paper tape layer 2 and the bamboo tape layer 1 are both wound together. Compared to directly attaching paper, the wound paper tape layer 2 attached to the bamboo tape layer 1 provides better torsional resistance from a force perspective.

[0107] Specifically, in this embodiment, adjacent coils of the paper tape 4 are overlapped, and the paper tape layer 2 is formed by spiral winding. The purpose is: in order to reduce the manufacturing difficulty and considering the relatively soft texture of the paper tape 4, the paper tape layer 2 is generated by overlapping adjacent coils of the paper tape 4. At the same time, the paper tape layer 2 in which adjacent coils are stacked layer by layer has better waterproof performance than the joint structure. Preferably, the overlap range between the coils of the paper tape 4 is 1-3mm, preferably 1mm, 1.5mm or 2mm. The overlap value is positively correlated with the spiral angle of the paper tape 4.

[0108] In addition, the bamboo tape 3 and the paper tape 4 are wound in the same direction; that is, in order to allow the seams generated by the winding of the bamboo tape 3 and the seams generated by the winding of the paper tape 4 to cover each other and avoid excessive interlacing of the seams, the bamboo tape 3 and the paper tape 4 in the embodiment of the present invention are conventionally wound in the same direction.

[0109] Alternatively, the bamboo tape 3 and the paper tape 4 are wound in opposite directions; that is, in order to improve the tensile and torsional properties of the straw, the bamboo tape 3 and the paper tape 4 are wound in opposite directions. When encountering torsional force, the bamboo tape layer 1 and the paper tape layer 2 with opposite rotation directions provide restraint force to each other, making it less likely to deform.

[0110] Example 5

[0111] On the basis of the first embodiment, the spiral angle of the bamboo tape 3 is smaller than the spiral angle of the paper tape 4 .

[0112] That is, in this embodiment, in order to reduce the seams of the paper tape 4, the spiral angle of the bamboo tape layer 1 is smaller than the spiral angle of the paper tape layer 2; at the same time, the spiral angle of the paper tape 4 is different from the spiral angle of the bamboo tape 3, so as to avoid the overlap of the seams of the bamboo tape layer 1 and the paper tape layer 2, which would affect the waterproof and torsional performance of the straw.

[0113] Specifically, the helical angle of the bamboo tape 3 is 45°, and the helical angle of the paper tape 4 is 50°.

[0114] Example 6

[0115] Based on the first embodiment, the width of the inner bamboo tape 3 or paper tape 4 is smaller than that of the outer bamboo tape 3 or paper tape 4. That is, the width of the bamboo tape 3 or paper tape 4 used in the bamboo tape layer 1 or paper tape layer 2 increases from the inside to the outside, making it easier for the bamboo tape 3 or paper tape 4 to cover the seams of the inner layer, while reducing the seams on the outer layer and improving the sealing performance of the straw.

[0116] Specifically, the width of the paper tape or bamboo tape located at the outer layer is 1.15 times the width of the paper tape or bamboo tape located at the inner layer.

[0117] Example 7

[0118] Based on Example 1, an adhesive layer is provided between the bamboo tape layer 1 and the paper tape layer 2. Specifically, the bamboo tape layer 1 and the paper tape layer 2 are attached by gluing. Specifically, the opposing surfaces of the bamboo tape layer 1 and the paper tape layer 2 are provided with adhesive layers to enhance the attachment effect. As shown in Figure 4, the adhesive layer is provided between the bamboo tape layer 1 and the paper tape layer 2.

[0119] Example 8

[0120] A method for preparing a straw, comprising:

[0121] The step of forming the bamboo tape layer 1 is to spirally wind the bamboo tape 3 into the bamboo tape layer 1; the bamboo tape 3 is made of raw bamboo through mechanical processing; the step of forming the paper tape layer 2 is to spirally wind the paper tape 4 into the paper tape layer 2; the paper tape is attached to at least part of the surface of the bamboo tape layer.

[0122] The bamboo strip comprises: a strip formed by cutting from one end of a bamboo piece to the other end along the fiber direction of the bamboo. The thickness of the bamboo strip in the embodiment of the present invention ranges from 0.25 mm to 0.5 mm.

[0123] The paper tape at least includes a strip formed by cutting kraft paper, food-grade coated paper or reinforced paper. The thickness of the paper tape in this embodiment is in the range of 60g / cm 2 .

[0124] Example 9

[0125] On the basis of Example 8, the steps for forming the bamboo tape layer 1 are specifically as follows: the bamboo tape 3 is spirally wound to form a single-layer bamboo tube, and then the paper tape 4 is tightly wound on the outer surface of the single-layer bamboo tube to form a composite layer; that is, during the manufacturing process, the bamboo tape 3 is first wound as the inner layer as the base layer to provide good support for the subsequent winding of the paper tape 4, thereby avoiding the collapse of the paper tape layer during the winding process; at the same time, since the paper tape 4 has strong toughness, the friction force is used to compress and strengthen the bamboo tape layer during winding.

[0126] Example 10

[0127] Based on Example 8, the steps for forming the paper tape layer 2 are as follows: Paper tape 4 is spirally wound to form a single-layer paper tube; then, bamboo tape 3 is tightly wound around the outer surface of the single-layer paper tube to form a composite layer. The principle behind this is that because paper tape 4 has greater tension and toughness than bamboo tape, it is easier to control during the winding process than bamboo tape 3. To reduce the difficulty of preparation, paper tape 4 is first wound as the inner layer into the single-layer paper tube. This provides a good adhesion surface for the subsequent bamboo tape 3, preventing slippage or misalignment during winding.

[0128] Preferably, after forming the composite layer, the paper tape 4 is tightly wound around the outer surface of the composite layer. Since the bamboo tape layer 1 is located on the outside of the composite layer at this time and lacks restraint and reinforcement, the paper tape layer 2 is wound outside the outer surface of the bamboo tape layer 1 to provide a compacting force to the bamboo tape layer 1. At the same time, the paper tape layer 2 absorbs burrs on the surface of the bamboo tape layer 1, improving the user experience.

[0129] Specifically, the bamboo tape layer and the paper tape layer are wound with a belt winder, and there is at least one group of winding mechanisms. In order to make the winding process smooth and alleviate the winding resistance, one or more groups of winding mechanisms can be connected after one winding according to the straw structure.

[0130] Example 11

[0131] In addition to the ninth or tenth embodiment, adjacent spirally wound coils of paper tape 4 are laminated. Specifically, during the manufacturing process, to enhance the overall strength of the straw, the paper tape layer 2 and the bamboo tape layer 1 are simultaneously wound and formed. Compared to directly attaching paper, the wound paper tape layer 2 attached to the bamboo tape layer 1 provides greater torsional resistance from a force perspective.

[0132] The adjacent spirally wound layers of bamboo tape 3 are joined. To improve the forming efficiency of the bamboo tape layer 1, the adjacent spirally wound layers of bamboo tape 3 are joined, i.e., the adjacent spiral layers of bamboo tape 3 do not overlap but fit tightly together. Furthermore, the spiral layers are joined together, resulting in a smooth surface with no protrusions on the bamboo tape layer 1, thus avoiding gaps after the paper tape layer 2 is attached.

[0133] Example 12

[0134] Based on the ninth or tenth embodiment, before the bamboo tape layer 1 is formed, the step of gluing the bamboo tape 3 to the composite paper is further included. Specifically, to enhance the transverse tensile strength of the bamboo tape 3 during the winding process, the composite paper and the bamboo tape 3 are glued together before winding. After the bamboo tape 3 is wound to form the bamboo tape layer 1, the facing surfaces of the composite paper and the paper tape layer 2 are glued and attached.

[0135] The application examples of the method for preparing a straw of the present invention are as follows:

[0136] The specific steps for making a straw with the paper tape layer 2 located outside the bamboo tape layer 1 are as follows:

[0137] First, the bamboo strip 3 is polished on both sides before manufacturing;

[0138] Then, before winding, the attached surfaces of the bamboo tape 3 and the paper tape 4 are glued separately (or only the attached surfaces of the paper tape 4 and the bamboo tape 3 are glued to save manufacturing costs), even if the glued surfaces of the paper tape 4 and the bamboo tape 3 are opposite to each other, the width of the paper tape 4 is 1.05-1.3 times (preferably 1.15 times) of the width of the bamboo tape 3, and the bamboo tape 3 is wound close to the winding mold core through the guiding mechanism to form an inner bamboo tape layer 1, and the paper tape 4 is attached to the bamboo tape layer 1 and wound to form an outer paper tape layer 2; during the winding process, the guiding mechanism is controlled to wind according to different spiral angles, wherein the spiral angle of the paper tape 4 is greater than the spiral angle of the bamboo tape 3. Specifically, the helical angle of the bamboo tape 3 is fixed at 45°. When winding, the edges of the bamboo tape 3 are tightly attached to each other without overlapping. The helical angle of the paper tape 4 is 55°. When winding, the paper tapes 4 overlap with each other (the overlapping width is positively correlated with the helical angle of the paper tape 4). The paper tape 4 gradually wraps the bamboo tape layer 1 to form a composite cylinder.

[0139] Finally, the finished cylinder is cut into straws according to preset lengths.

[0140] In addition, in order to prevent the bamboo tape 3 from breaking during the winding process, the bamboo tape 3 is first glued to the composite paper before winding to enhance the lateral tensile strength of the bamboo tape 3; after the bamboo tape 3 is wound, the composite paper layer is on the outer surface of the bamboo tape 3, and then the paper tape 4 is wound on the outer surface of the composite paper layer and glued into a cylinder.

[0141] In summary, the present invention provides a straw and a preparation method thereof. The original bamboo is cut into bamboo strips and the bamboo strips are rolled to form a bamboo strip layer as the structural support layer of the straw, thereby solving the problem of easy softening of paper straws. At the same time, a paper tape layer is attached to the bamboo tape layer, and the toughness of the paper tape itself is used to strengthen the bamboo tape layer, thereby solving the problem of poor tensile and torsional properties of bamboo straws. In addition, the bamboo paper straws disclosed in the present invention reduce the amount of bamboo tape used in straws compared to pure bamboo straws, and use paper tape and bamboo tape to attach, which reduces the manufacturing difficulty, and the finished product rate reaches more than 99%, while saving production costs.

[0142] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A straw, characterized in that: include: At least one bamboo tape layer, wherein the bamboo tape layer is a first tube formed by winding bamboo tapes; The bamboo belt is made of raw bamboo through mechanical processing; At least one paper tape layer, the paper tape layer comprising paper tape, the paper tape being attached to at least a portion of the surface of the first tube.

2. A straw according to claim 1, characterized in that: The paper tape layer is a second tube formed by winding the paper tape.

3. A straw according to claim 2, characterized in that: Adjacent coils of the paper tape are overlapped.

4. A straw according to claim 2, characterized in that: The bamboo tape and the paper tape are wound in the same rotation direction.

5. A straw according to claim 2, characterized in that: The bamboo tape and the paper tape are wound in opposite directions.

6. A straw according to claim 2, characterized in that: The helical angle of the bamboo tape is smaller than the helical angle of the paper tape.

7. A straw according to claim 6, characterized in that: The helical angle of the bamboo belt winding is in the range of 30°-45°.

8. A straw according to claim 6, characterized in that: The spiral angle of the paper tape winding ranges from 46° to 70°.

9. A straw according to claim 2, characterized in that: The paper tape layer includes at least one paper tape attached to at least a portion of the inner surface of the first tube.

10. A straw according to claim 9, characterized in that: The paper tape layer further includes at least one paper tape attached to at least a portion of the outer surface of the first tube.

11. A straw according to claim 2, characterized in that: The paper tape layer further includes at least one paper tape attached to at least a portion of the outer surface of the first tube.

12. A straw according to any one of claims 9 to 11, characterized in that: The width of the bamboo tape or the paper tape located in the inner layer is smaller than the width of the bamboo tape or the paper tape located in the outer layer.

13. A straw according to claim 12, characterized in that: The width of the bamboo tape located in the innermost layer ranges from 15 mm to 30 mm.

14. A straw according to claim 12, characterized in that: The width of the paper tape located in the innermost layer ranges from 20 mm to 29 mm.

15. The straw according to claim 1, characterized in that: A glue layer is arranged between the bamboo tape layer and the paper tape layer.

16. A straw according to claim 15, characterized in that: The opposite surfaces of the bamboo tape layer and the paper tape layer are respectively provided with glue layers.

17. A straw according to claim 1, characterized in that: Adjacent circles of the bamboo belt are joined together.

18. A method for preparing a straw, characterized in that: include: A bamboo tape layer forming step, wherein the bamboo tape is wound into a bamboo tape layer; the bamboo tape is made of raw bamboo through mechanical processing; and, a paper tape layer forming step of winding the paper tape to form the paper tape layer; The paper tape is attached to at least a portion of the surface of the bamboo tape layer.

19. The method for preparing a straw according to claim 18, characterized in that: The step of forming the bamboo strip layer specifically comprises: spirally winding the bamboo strip to form a single-layer bamboo tube; The paper tape layer forming step specifically comprises: tightly winding the paper tape around the outer surface of the single-layer bamboo tube to form a composite layer.

20. The method for preparing a straw according to claim 18, characterized in that: The paper tape layer forming step specifically comprises: spirally winding the paper tape to form a single-layer paper tube; The step of forming the bamboo tape layer is specifically as follows: tightly winding the bamboo tape around the outer surface of the single-layer paper tube to form a composite layer.

21. The method for preparing a straw according to claim 20, characterized in that: Also includes the steps: The paper tape is tightly wound around the outer surface of the composite layer.

22. A method for preparing a straw according to any one of claims 19 to 21, characterized in that: The helical angle of the paper tape winding is greater than the helical angle of the bamboo tape winding.

23. The method for preparing a straw according to claim 22, characterized in that: The helical angle of the bamboo belt winding is 30°-45°.

24. The method for preparing a straw according to claim 22, characterized in that: The spiral angle of the paper tape winding ranges from 46° to 70°.

25. A method for preparing a straw according to any one of claims 19 to 21, characterized in that: Adjacent coils of the spirally wound paper tape are overlapped.

26. A method for preparing a straw according to any one of claims 19 to 21, characterized in that: The adjacent circles of the spirally wound bamboo belt are joined.

27. A method for preparing a straw according to any one of claims 19 to 21, characterized in that: Also includes the glue layer formation step: Before winding, glue is applied on the opposite sides where the paper tape and bamboo tape are attached; Or the opposite sides where the paper tape and the bamboo tape are attached are glued separately.

28. A method for preparing a straw according to any one of claims 19 to 21, characterized in that: Before the bamboo belt layer is formed, the steps include: Glue the bamboo strips to the composite paper.

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