Corrugated reinforced PHA fully degradable straw and preparation process thereof

Abstract

The application relates to a corrugated reinforced PHA full-degradation straw and a preparation process thereof, and belongs to the technical field of full-biodegradable straws, and comprises a straw body which is a hollow circular tubular structure formed by integral extrusion, the straw body comprises an upper straight pipe section, a middle corrugated bending section and a lower straight pipe section in sequence along the axial direction, the middle corrugated bending section is composed of multiple rings of annular folds arranged continuously at equal intervals, the top end of the upper straight pipe section is a flat-cut opening, and the bottom end of the lower straight pipe section is a flat-cut opening. The application has the effect of improving the flexibility of the straw.

Description

Technical Field

[0001] This invention relates to the field of fully biodegradable straw technology, and in particular to a corrugated reinforced PHA fully biodegradable straw and its preparation process. Background Technology

[0002] With the global push for plastic bans, biodegradable straws have become an important alternative to traditional plastics. Polyhydroxyalkanoates (PHA) have attracted much attention due to their excellent marine biodegradability and biocompatibility. However, conventional PHA straws perform poorly in practical applications such as high-temperature resistance and bending resistance, exhibiting problems such as poor heat resistance, insufficient flexibility, and easy deformation and breakage. This severely restricts their large-scale promotion and the improvement of user experience.

[0003] Currently, commercially available biodegradable straws are mainly divided into two categories: pure PHA straight-wall straws and traditional rigid corrugated straws. Both have significant flexibility deficiencies. Pure PHA straight-wall straws are brittle and easily develop stress whitening and microcracks when bent, leading to rapid cracking. Furthermore, their resilience after bending is extremely poor, making them unable to withstand repeated dynamic bending. While traditional rigid corrugated straws incorporate a corrugated structure, the material itself lacks toughness, resulting in significant lag in rebound after bending. They are prone to breakage due to bending fatigue during repeated insertion, removal, or storage. In summary, current straw structures generally lack effective flexibility reinforcement designs, resulting in weak resistance to bending fatigue and creep. Under daily repeated bending conditions, the straw body is prone to irreversible plastic deformation, losing its original resilience and significantly shortening its effective service life. Summary of the Invention

[0004] To effectively improve the flexibility of straws, this application provides a corrugated reinforced PHA fully biodegradable straw.

[0005] Firstly, this application provides a corrugated reinforced PHA fully biodegradable straw, which adopts the following technical solution: A corrugated reinforced PHA fully biodegradable straw includes a tube body, which is a hollow cylindrical structure integrally extruded. The tube body includes an upper straight tube section, a middle corrugated bending section and a lower straight tube section in sequence along the axial direction. The middle corrugated bending section is composed of multiple ring-shaped pleats arranged continuously at equal intervals. The top end of the upper straight tube section is a flat-cut opening, and the bottom end of the lower straight tube section is a flat-cut opening.

[0006] By adopting the above technical solution, the integrity and cleanliness of the tube body are ensured by using a hollow cylindrical structure formed by integral extrusion molding. The upper straight tube section, the middle corrugated bending section, and the lower straight tube section are arranged sequentially along the axial direction, forming a flexible bending zone in the middle of the tube body composed of multiple continuous annular pleats with equal spacing. When the straw is bent, the corrugated pleats can undergo reversible elastic deformation, effectively dispersing bending stress and avoiding stress concentration, stress whitening, and microcracks in the PHA material due to its brittleness. This significantly improves the flexibility and bending fatigue resistance of the straw, while the flat-cut openings at both ends facilitate insertion into beverage containers and consumption.

[0007] Optionally, the upper straight pipe section and the lower straight pipe section have the same inner diameter and their inner cavities are interconnected.

[0008] By adopting the above technical solution, the inner diameter of the upper straight pipe section and the lower straight pipe section are the same and the inner cavity is connected, so that the liquid flow cross section remains uniform throughout the entire process, avoiding throttling or turbulence caused by sudden changes in pipe diameter, and ensuring smooth suction.

[0009] Optionally, the upper end of the corrugated section is smoothly connected to the lower end of the upper straight pipe section, and the lower end of the corrugated section is smoothly connected to the upper end of the lower straight pipe section.

[0010] By adopting the above technical solution, the upper end of the middle corrugated bend section and the lower end of the upper straight pipe section, as well as the lower end of the middle corrugated bend section and the upper end of the lower straight pipe section, are all smoothly connected, eliminating stress concentration sources at the abrupt interface, enabling bending stress to be smoothly transmitted along the pipe body, and preventing fatigue cracking or fracture at the transition connection.

[0011] Optionally, the annular folds are formed by alternating continuous annular grooves and annular protrusions.

[0012] By adopting the above technical solution, when bending, the protrusions on the inner side of the bend are compressed and the grooves tend to close more, while the protrusions on the outer side of the bend are stretched and the grooves open appropriately. This coordinated deformation of alternating concave and convex shapes effectively absorbs and releases bending energy, giving the tube body good springback recovery ability, reducing the accumulation of plastic deformation, and significantly improving its resistance to bending fatigue and creep.

[0013] Optionally, the wall thickness of the corrugated bend section is less than the wall thickness of the upper straight section and the lower straight section.

[0014] By adopting the above technical solution, the wall thickness of the corrugated section is set to be less than that of the upper and lower straight sections, which further enhances the flexibility of the corrugated section, reduces the bending torque required, and makes the bending operation easier.

[0015] Optionally, the corrugated bend section is located at 3 / 4 of the length of the tube body.

[0016] By adopting the above technical solution, the corrugated bending section is positioned at 3 / 4 of the length of the tube, which conforms to the typical bending position of the straw when it is inserted into the container at the bottom and extended to the mouth at the top during daily drinking. This concentrates the bending deformation on the pre-designed flexible corrugated section, avoiding unexpected damage in the upper or lower straight sections, optimizing the stress distribution of the straw, and improving ease of use and structural reliability.

[0017] Optionally, the overall length of the tube body is 15cm to 25cm, and the length of the corrugated bending section accounts for 8% to 12% of the overall length of the tube body.

[0018] By adopting the above technical solution, the overall length of the tube is set between 15cm and 25cm, which is suitable for the depth of conventional beverage cups and bottles; the length of the corrugated bending section accounts for 8% to 12% of the total length of the tube, which ensures that there is enough flexible area to adapt to different bending angles and repeated insertion and removal needs, while avoiding the tube rigidity from being too long or the tube wall from collapsing when sucking.

[0019] Secondly, this application provides a method for preparing a corrugated reinforced PHA fully biodegradable straw, using the following technical solution: A manufacturing process for a corrugated reinforced PHA fully biodegradable straw includes the following steps: S1. Melt extrusion: The dried PHA is melt extruded to obtain a hollow tube blank; S2. Gradient air cooling and shaping: The hollow tube blank is cooled and shaped step by step using a gradient air cooling and shaping process; S3. After traction and fixed-length cutting, a corrugated reinforced PHA fully biodegradable straw is obtained.

[0020] Optionally, in S1, the extrusion temperature is 155-165°C.

[0021] By adopting the above technical solution, the extrusion temperature is precisely controlled within the low-temperature plasticizing window of 155-165℃. This allows the PHA material to obtain sufficient melt flowability while effectively inhibiting the thermal degradation and chain breaking reaction of the molecular chain, thus fully preserving the original high molecular weight and inherent toughness of PHA, thereby ensuring that the straw maintains high toughness and high impact resistance.

[0022] Optionally, in S2, the gradient air cooling shaping process is divided into three stages of sequential cooling: the first stage air cooling temperature is 65℃-80℃, the second stage air cooling temperature is 45℃-60℃, and the third stage air cooling temperature is 30℃-40℃.

[0023] By adopting the above technical solution, the three-stage gradient air-cooling shaping process creates conditions for uniform crystallization in the corrugated region, taking into account the slow crystallization speed and sensitivity to the cooling process of PHA.

[0024] The first stage of warm air cooling at 65℃-80℃ allows the PHA molecular chains to smoothly enter the initial stage of crystallization within a fully active window. Uniform and fine crystal nuclei are formed simultaneously at the peaks and troughs of the corrugations, reducing the surface layer from rapid solidification, core layer from lagging, and uneven shrinkage caused by excessive temperature difference during sudden cooling, and reducing the accumulation of residual stress inside the corrugated structure.

[0025] The second stage, with continuous cooling from 45℃ to 60℃, drives the crystal nuclei to grow synchronously and uniformly along the entire contour of the corrugations. This results in uniform crystallinity and stable micro-orientation structure in the arc transition surface and the micro-structure region with varying wall thickness, thereby giving the corrugated pipe a consistent overall stiffness and high-temperature creep resistance, and reducing weak points caused by local crystallization differences.

[0026] The third stage of low-temperature air cooling at 30℃-40℃ smoothly dissipates the temperature gradient inside and outside the tube wall and in all parts of the corrugations. The uniformly solidified crystalline phase precisely shapes the corrugation morphology and size, eliminating post-crystallization shrinkage stress. The precise connection of the three-stage temperature control achieves coordinated regulation of the entire process from nucleation uniformity and growth synchronization to morphological stability, ensuring the complete homogenization of microcrystalline structure in the corrugated area. This results in a finished straw with high toughness, high heat resistance, and high impact resistance.

[0027] In summary, this application includes at least one of the following beneficial technical effects: A corrugated reinforced PHA fully biodegradable straw utilizes an integrally extruded hollow cylindrical structure to ensure the integrity and cleanliness of the straw body. The upper straight section, the middle corrugated bending section, and the lower straight section are arranged sequentially along the axial direction, forming a flexible bending zone in the middle of the straw body composed of multiple continuous annular pleats with equal spacing. When the straw is bent, the corrugated pleats can undergo reversible elastic deformation, effectively dispersing bending stress and preventing stress concentration, stress whitening, and microcracks in the PHA material due to its brittleness. This significantly improves the straw's flexibility and resistance to bending fatigue. At the same time, the flat-cut openings at both ends facilitate insertion into beverage containers and consumption. By precisely controlling the extrusion temperature within the low-temperature plasticizing window of 155-165℃, PHA material can achieve sufficient melt flowability while effectively inhibiting the thermal degradation and chain breaking reaction of molecular chains, thus fully preserving the original high molecular weight and inherent toughness of PHA, thereby ensuring that the straw maintains high toughness and impact resistance. By employing a three-stage gradient air-cooling shaping process, the first stage uses a suitable temperature to ensure uniform crystal nucleus formation and avoid stress accumulation caused by rapid cooling. The second stage features a moderate cooling gradient, allowing for synchronous crystal nucleus growth and uniform crystallinity throughout the tube wall, eliminating structural weak points. The third stage, a low-temperature section, smoothly eliminates the temperature gradient, ensuring precise morphological shaping and completely eliminating post-shrinkage stress. Therefore, this entire temperature control system allows the PHA material to fully retain its polymer chain structure and original mechanical properties, resulting in a final product with excellent toughness, impact resistance, and heat resistance. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the corrugated reinforced PHA fully biodegradable straw product in the embodiments of this application.

[0029] Figure 2 This is a schematic diagram of the corrugated bending section in an embodiment of this application.

[0030] Explanation of reference numerals in the attached drawings: 1. Pipe body; 11. Upper straight pipe section; 12. Middle corrugated bend section; 121. Annular groove; 122. Annular protrusion; 13. Lower straight pipe section. Detailed Implementation

[0031] The raw materials in this application include the following: PHA: Uses product brand Blue Crystal from Blue Crystal Biotechnology Co., Ltd. TM The commercially available product PHABH2-ES004.

[0032] The present application will be further described in detail below with reference to embodiments and comparative examples. Example

[0033] A manufacturing process for a corrugated reinforced PHA fully biodegradable straw includes the following steps: S1. Weigh 10kg PHA and put it into a twin-screw extruder for melt plasticization; wherein, the temperature control of each zone of the twin-screw extruder is as follows: feeding section 155℃, plasticizing section 158℃, homogenizing section 162℃, die head section 163℃, and the screw speed is set to 45rpm. After the material is fully melted, blended and plasticized, it is extruded through the die head to obtain a hollow corrugated tube blank.

[0034] S2. The hollow corrugated tube blank prepared in S1 is fed into a dedicated three-stage gradient air-cooling and shaping device with a total length of 6m. Under the negative pressure adsorption of -0.02MPa, the tube blank is made to stick tightly to the inner wall of the shaping mold, and is successively cooled and shaped by passing through three independent temperature-controlled air-cooling zones. The first stage of air-cooling has a temperature of 70℃, a wind speed of 3m / s, and a residence time of 4s; the second stage of air-cooling has a temperature of 50℃, a wind speed of 4m / s, and a residence time of 5s; and the third stage of air-cooling has a temperature of 35℃, a wind speed of 5m / s, and a residence time of 3s. All stages of air-cooling adopt a side-blowing air supply method, and the air supply direction is at a 45° angle to the direction of tube blank movement.

[0035] S3. The corrugated straw blank, after being cooled and shaped by gradient air, is pulled and conveyed at a constant speed of 12m / min by a traction machine, and then cut to a standard length of 210mm by a servo fixed-length cutting machine, finally producing the corrugated reinforced PHA fully biodegradable straw product.

[0036] Reference Figure 1A corrugated reinforced PHA fully biodegradable straw includes a tube body 1, which is made of PHA material through an integral extrusion molding process, presenting an overall hollow circular tube structure. The tube body 1 includes, from top to bottom, an upper straight tube section 11, a middle corrugated bending section 12, and a lower straight tube section 13, which together form a continuous inner cavity. The top end of the upper straight tube section 11 and the bottom end of the lower straight tube section 13 are both flat-cut openings, which facilitate drinking and insertion into beverage containers.

[0037] Reference Figure 1 The inner diameters of the upper straight pipe section 11 and the lower straight pipe section 13 are consistent and their inner cavities are interconnected, so that the cross-section remains unchanged when the liquid flows in the straw, avoiding throttling or turbulence and ensuring smooth suction.

[0038] Reference Figure 1 and Figure 2 The upper corrugated bending section 12 is composed of multiple ring-shaped pleats arranged continuously at equal intervals. The ring-shaped pleats are formed by alternating continuous ring-shaped grooves 121 and ring-shaped protrusions 122, creating a stretchable and deformable structure. The upper end of the corrugated bending section 12 and the lower end of the upper straight pipe section 11, as well as the lower end of the corrugated bending section 12 and the upper end of the lower straight pipe section 13, are connected by a smooth transition without abrupt interfaces. During bending, the stress can be smoothly transmitted along the pipe body 1, effectively preventing fatigue cracking at the connection.

[0039] Reference Figure 1 To ensure the corrugated section possesses both good flexibility and resilience, the wall thickness of the middle corrugated bending section 12 is less than that of the upper straight pipe section 11 and the lower straight pipe section 13. In this embodiment, the wall thickness of the upper straight pipe section 11 and the lower straight pipe section 13 can be 0.4 mm, and the wall thickness of the middle corrugated bending section 12 can be 0.2 mm.

[0040] Reference Figure 1 Based on everyday usage scenarios, the corrugated bending section 12 is located at 3 / 4 of the length of the tube body 1, near the top of the straw, to match the typical bending shape of the straw with its lower end inserted into the container and its upper end containing the inlet. The overall length of the tube body 1 is 15cm to 25cm, and the length of the corrugated bending section 12 accounts for 8% to 12% of the overall length of the tube body 1. In this embodiment, the total length of the tube body 1 is 20cm, of which the upper straight tube section 11 is about 3cm long, the corrugated bending section 12 is about 2cm long, and the lower straight tube section 13 is about 15cm long. At this point, the corrugated section is located 15cm from the bottom, which corresponds exactly to three-quarters of the length of the tube body 1. The length of the corrugated section accounts for 10%, ensuring sufficient flexibility to adapt to bending and repeated insertion and removal needs, while avoiding a decrease in the rigidity of the tube body 1 or collapse of the tube wall during sucking due to an excessively long corrugated section.

[0041] Reference Figure 1The previous type of corrugated reinforced PHA fully biodegradable straw is integrally extruded from PHA material. The tube body 1 includes an upper straight tube section 11, a middle corrugated bending section 12, and a lower straight tube section 13. Its core of flexibility enhancement lies in the multi-ring annular pleated structure of the middle corrugated bending section 12. This annular pleated structure is composed of continuous annular grooves 121 and annular protrusions 122 arranged alternately. The middle corrugated bending section 12 is set at about three-quarters of the total length of the tube body 1, which corresponds exactly to the typical bending position in daily use. This concentrates the bending deformation in the preset flexible area, significantly improving the straw's flexibility and resistance to bending fatigue. At the same time, the flat cut openings at both ends facilitate insertion into beverage containers and consumption.

[0042] Comparative Example 1 Comparative Example 1, based on the preparation process of Example 1, uses a single-temperature air-cooling shaping process in S2 to gradually cool and shape the hollow tube blank. The air-cooling temperature is 40°C, the air velocity is 4m / s, and the residence time is 10s. A side-blowing air supply method is used, with the air supply direction at a 45° angle to the tube blank movement direction, and the other conditions remain unchanged.

[0043] Comparative Example 2 Comparative Example 2, based on the preparation process of Example 1, uses a single-temperature air-cooling shaping process in S2 to gradually cool and shape the hollow tube blank. The air-cooling temperature is 65°C, the air velocity is 4m / s, and the residence time is 10s. A side-blowing air supply method is used, with the air supply direction at a 45° angle to the tube blank movement direction, and the other conditions remain unchanged.

[0044] Performance testing The corrugated reinforced PHA fully degradable pipettes of Example 1 and Comparative Examples 1-2 were analyzed, and the specific detection methods are as follows: toughness The test was conducted in accordance with GB / T1040.2-2006 "Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets", using type 5 specimens and a tensile speed of 50 mm / min, to test the longitudinal tensile elongation at break (%) of the PHA composition.

[0045] Impact resistance The test was conducted in accordance with GB / T1843-2008 "Determination of Impact Strength of Plastic Cantilever Beams". A type A notch was used, the sample size was 80mm×10mm×4mm, the pendulum energy was 2.75J, and the notched impact strength (kJ / m²) of the PHA composite material was tested.

[0046] Based on the above detection method, the test results of Example 1 and Comparative Examples 1-2 were obtained, as shown in Table 1 below.

[0047] Table 1 Performance test results for Example 1 and Comparative Examples 1-2

[0048] Referring to Table 1, a comparison between Example 1 and Comparative Examples 1-2 shows that Example 1 exhibits significantly better toughness and impact resistance than Comparative Examples 1-2. This is because, on the one hand, the gradient air-cooling shaping process can precisely control the cooling process, significantly reducing residual internal stress and optimizing the crystal morphology. Comparative Examples 1-2, which use single-temperature air-cooling shaping, cannot simultaneously meet the dual requirements of corrugated structure shaping and internal stress release: if the air-cooling temperature is too high, the tube blank solidification rate is insufficient, the corrugated structure is prone to collapse and deformation, and the structural reinforcement effect is weakened; if the air-cooling temperature is too low, the cooling rate is too fast, and there is still a significant problem of residual internal stress, resulting in very limited improvement in toughness and impact resistance.

[0049] Examples 2-5 Examples 2-5 are based on the preparation method of Example 1, but the extrusion temperature (digging section) is adjusted, as shown in Table 2.

[0050] The corrugated reinforced PHA fully degradable straws from Examples 2-5 were subjected to the above performance tests, and the test results are shown in Table 2.

[0051] Table 2. Extrusion temperature and performance test results for Examples 1 and 2-5.

[0052] Referring to Table 2, a comparison of Example 1 and Examples 2-5 shows that the toughness and impact resistance of Example 1 are significantly better than those of Examples 2-5. This is because when the extrusion temperature is too low, the PHA resin is not sufficiently plasticized, leaving trace amounts of unplasticized crystal points and solid particles in the melt, resulting in poor melt flowability and component uniformity. After molding and cooling, these unmelted particles become mechanical weak points inside the material, easily causing stress concentration at the two-phase interface under external force, leading to rapid crack propagation and ultimately a decrease in toughness and impact resistance.

[0053] When the extrusion temperature is too high, the high temperature will cause the PHA molecular chain to undergo thermo-oxidative degradation to varying degrees, resulting in a decrease in number-average molecular weight, a shortening of molecular chain length, and a weakening of intermolecular entanglement and physical cross-linking effects. Molecular weight is the core factor that determines the toughness and impact resistance of polyester materials. A decrease in molecular weight will directly cause a decline in the mechanical properties of the material itself. Moreover, the higher the temperature and the more significant the degree of degradation, the more obvious the decrease in toughness and impact resistance.

[0054] In summary, precisely controlling the extrusion temperature within the low-temperature plasticizing window of 155-165℃ allows PHA material to achieve sufficient melt flow while effectively inhibiting the thermal degradation and chain scission reactions of the molecular chains, thus fully preserving the original high molecular weight and inherent toughness of PHA, thereby ensuring that the straw maintains high toughness and impact resistance.

[0055] Examples 6-9 Examples 6-9 are based on the preparation method of Example 1, with adjustments made to the first-stage air-cooling temperature, the second-stage air-cooling temperature, and the third-stage air-cooling temperature, as shown in Table 3.

[0056] Performance testing The corrugated reinforced PHA fully degradable straws of Examples 1 and 6-9 were analyzed using the following specific testing methods: Heat resistance The Vicat softening temperature (VST) of the PHA composition material was tested in accordance with GB / T1633-2000 "Determination of Vicat softening temperature (VST) of thermoplastic plastics". The A50 method was used, the heating rate was 50℃ / h, the load was 10N, and the cross-sectional area of ​​the indenter was 1mm².

[0057] Based on the above detection method, the test results of Examples 1 and 6-9 were obtained, as shown in Table 3 below.

[0058] Table 3. Extrusion temperature and performance test results for Examples 1 and 6-9.

[0059] Comparing Examples 1 and 6-9, it can be seen that the toughness and impact resistance of Example 1 are significantly better than those of Examples 6-9. This is because the first stage temperature is suitable, crystal nuclei are generated uniformly, and stress accumulation caused by sudden cooling is reduced; the second stage cooling gradient is moderate, crystal nuclei grow synchronously, crystallinity is uniform throughout the pipe wall, and there are no structural weak points; the third stage low temperature section smoothly eliminates the temperature gradient, the morphology is accurately shaped, and post-shrinkage stress is eliminated.

[0060] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A corrugated reinforced PHA fully biodegradable straw, characterized in that, It includes a tube body (1), which is a hollow cylindrical structure integrally extruded. The tube body (1) includes an upper straight tube section (11), a middle corrugated bending section (12) and a lower straight tube section (13) in sequence along the axial direction. The middle corrugated bending section (12) is composed of multiple ring-shaped folds arranged continuously at equal intervals. The top end of the upper straight tube section (11) is a flat cut opening, and the bottom end of the lower straight tube section (13) is a flat cut opening.

2. The corrugated reinforced PHA fully biodegradable straw according to claim 1, characterized in that, The upper straight pipe section (11) and the lower straight pipe section (13) have the same inner diameter and their inner cavities are interconnected.

3. The corrugated reinforced PHA fully biodegradable straw according to claim 1, characterized in that, The upper end of the corrugated section (12) is smoothly connected to the lower end of the upper straight pipe section (11), and the lower end of the corrugated section (12) is smoothly connected to the upper end of the lower straight pipe section (13).

4. The corrugated reinforced PHA fully biodegradable straw according to claim 1, characterized in that, The annular folds are composed of alternating annular grooves (121) and annular protrusions (122).

5. A corrugated reinforced PHA fully biodegradable straw according to claim 4, characterized in that, The wall thickness of the corrugated bend section (12) is less than the wall thickness of the upper straight section (11) and the lower straight section (13).

6. The corrugated reinforced PHA fully biodegradable straw according to claim 1, wherein the corrugated bending section (12) is located at 3 / 4 of the length of the tube body (1).

7. A corrugated reinforced PHA fully biodegradable straw according to claim 6, characterized in that, The overall length of the tube body (1) is 15cm to 25cm, and the length of the corrugated bending section (12) accounts for 8% to 12% of the overall length of the tube body (1).

8. The preparation process of a corrugated reinforced PHA fully biodegradable straw according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Melt extrusion: The dried PHA is melt extruded to obtain a hollow tube blank; S2. Gradient air cooling and shaping: The hollow tube blank is cooled and shaped step by step using a gradient air cooling and shaping process; S3. After traction and fixed-length cutting, a corrugated reinforced PHA fully biodegradable straw is obtained.

9. A corrugated reinforced PHA fully biodegradable straw according to claim 8, characterized in that, In S1, the extrusion temperature is 155-165°C.

10. A corrugated reinforced PHA fully biodegradable straw according to claim 8, characterized in that, In S2, the gradient air-cooling shaping process is divided into three stages of sequential cooling: the first stage air-cooling temperature is 65℃-80℃, the second stage air-cooling temperature is 45℃-60℃, and the third stage air-cooling temperature is 30℃-40℃.

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