Recyclable Pick ball and manufacturing method thereof

Abstract

The invention discloses a recyclable Pick ball and a manufacturing method thereof, and relates to the field of plastic recycling, the recyclable Pick ball comprises a ball body, the ball body is made of functionalized TPAE, a modified epoxy functionalized acrylic polymer and modified PEGDA, and a mark is carved on the ball body through laser carving. Functionalized TPAE, a modified epoxy functionalized acrylic polymer and modified PEGDA are adopted as sphere materials, and laser carving is adopted to carve the mark, so that the problem that the performance of a recycled material is reduced due to repeated hot working and ink printing of a traditional Pick sphere is solved; in the recovery process, the modified epoxy functionalized acrylic polymer is migrated to a molecular chain fracture position for chemical repair, the mechanical property of the material is recovered, and the modified PEGDA forms a surface crosslinking layer through UV curing, so that laser carving replaces ink printing to form a clear LOGO, foreign matter points are prevented from being generated, the surface wear resistance and laser carving definition are improved, and the service life of the material is prolonged. The Pick ball can still keep excellent impact strength, elongation at break and surface performance after multiple times of circulation.

Description

Technical Field

[0001] This invention relates to the field of plastic recycling, and more particularly to a recyclable pickle and its manufacturing method. Background Technology

[0002] Pickball is a ball sport that combines features of tennis, badminton, and table tennis. It is usually played in an area similar in size to a badminton court. The sport uses a perforated thermoplastic ball to hit a hard racket face. It has low requirements for the venue and is suitable for people of all ages, making it very popular.

[0003] The sport of pickleball has developed rapidly due to its widespread appeal, resulting in a large number of discarded balls. Traditional recycling methods rely on simply crushing and melting these discarded balls for re-granulation. During this process, the polymer formed from the discarded balls undergoes repeated thermal processing, causing molecular chain breakage and degradation. This leads to a significant decrease in key mechanical properties such as toughness and strength of the recycled material. If such degraded recycled material is mixed with virgin material for injection molding, it will not only cause defects such as insufficient mold filling and shrinkage cavities due to changes in rheological behavior, but also result in the final ball products failing to meet performance standards and having to be downgraded, thus preventing closed-loop recycling. In addition, the production of pickleballs requires ink printing for marking. However, in traditional recycling methods, the ink cannot be integrated with the base plastic, forming numerous tiny foreign matter points that become stress concentration points. This severely damages the material's uniformity, causing a sharp decline in toughness indicators such as impact strength and elongation, making the material brittle and unsuitable for pickleball recycling.

[0004] Therefore, a recyclable pickball and its manufacturing method are proposed to solve the problem that repeated heat processing and ink use degrade the performance of recycled materials, making them unusable for recycling. Summary of the Invention

[0005] The purpose of this invention is to provide a method for manufacturing recyclable pickles, which solves the problem that repeated heat processing and ink use degrade the performance of recycled materials, making them unusable for recycling.

[0006] To achieve this objective, the present invention adopts the following technical solution: A recyclable pickball includes a sphere made of functionalized TPAE, modified epoxy-functionalized acrylic polymer and modified PEGDA, and the sphere is laser-engraved with a logo.

[0007] A method for manufacturing recyclable pickles, the preparation method being used for the pickles of claim 1, the preparation method comprising the following steps: Step S1: Mix functionalized TPAE, modified epoxy-functionalized acrylic polymer and modified PEGDA to obtain a mixture; Step S2: Extrude the mixture through an extruder to obtain composite granules; Step S3: The composite particles are injection molded into spheres, and then the logo is engraved on the spheres using laser engraving to obtain Peak balls.

[0008] Step S1 specifically includes the following steps: Step S11: Functionalized TPAE, modified epoxy-functionalized acrylic polymer and modified PEGDA of the same particle size are mixed at room temperature to obtain a mixture. Step S12: After drying the mixture in a vacuum environment, cool it to room temperature, place the mixture on a vibrating screen for dispersion, and then seal and let it stand to obtain the mixture.

[0009] In step S11, the mass percentages of functionalized TPAE, modified epoxy-functionalized acrylic polymer, and modified PEGDA in the mixture are 75-85%, 8-12%, and 7-15%, respectively, and the mixing time is 15-20 min and the rotation speed is 200-400 rpm.

[0010] In step S12, the drying temperature is 70-90℃ and the time is 3-5h, the vacuum degree of the vacuum environment is (-0.1)-(-0.09)MPa, the mesh size of the vibrating screen is 20-40 mesh, and the sealing and standing time is 6-10h.

[0011] The modified epoxy-functionalized acrylic polymer is obtained according to the following steps: Functionalized TPAE particles were placed in acetone at 60-70℃ and stirred to swell for 1.5-2 hours to obtain the first solution a. GMA monomer and free radical initiator were added to the first solution a and reacted at 70-80℃ for 4-6 hours to obtain the second solution a; The second solution a was mixed with ethanol to obtain a precipitate, and the precipitate was washed with ethanol to obtain an intermediate. The intermediate was embrittled in liquid nitrogen and then ground at low temperature to obtain a modified epoxy-functionalized acrylic polymer.

[0012] The modified PEGDA is obtained according to the following steps: EVA was melted in a nitrogen atmosphere at 90-100°C, and then PEGDA and catalyst were added and reacted for 30-45 minutes. After the reaction is complete, a terminator is added, and the mixture is granulated using an underwater pelletizer to obtain EVA-g-PEGDA prepolymer particles. EVA-g-PEGDA prepolymer particles were blended with a photoinitiator in a single-screw extruder at a temperature of 80°C, and then cooled and granulated to obtain modified PEGDA.

[0013] The mixture is placed in a co-rotating twin-screw extruder and passed sequentially through the first, second, third, and fourth zones on the barrel of the co-rotating twin-screw extruder. After the mixture is discharged from the barrel, composite granules are obtained.

[0014] The temperature of the first zone is 155-165℃, the temperature of the second zone is 165-175℃, the temperature of the third zone is 170-180℃, the temperature of the fourth zone is 175-185℃, and the screw speed of the twin-screw extruder is 200-300 rpm.

[0015] Step S3 includes the following steps: Step S31: After placing the composite granules into the injection molding machine, the molten material is injected into the spherical cavity mold through the injection molding machine. After the molten composite granules cool and solidify, the preform is obtained. Step S32: Place the preform in a UV curing oven. After curing, use a fiber laser engraving machine to engrave the markings on the surface of the preform to obtain a Peak ball.

[0016] In step S31, the injection molding machine has a melt temperature of 185-190℃, an injection pressure of 60-80MPa, a holding pressure of 40-50MPa, and a holding time of 10-15s.

[0017] In step S32, the irradiation time of the UV curing oven is 60-90 seconds, the UV wavelength is 365 nm, and the UV light intensity is 50-100 mW / cm². 2 .

[0018] Compared with the prior art, the present invention has the following beneficial effects: This invention discloses a recyclable pickball and its manufacturing method. By using functionalized TPAE, modified epoxy-functionalized acrylic polymer, and modified PEGDA as the ball materials, and employing laser engraving to etch the logo, it effectively solves the problem of performance degradation of recycled materials caused by repeated heat processing and ink printing in traditional pickballs. The epoxy groups in the modified epoxy-functionalized acrylic polymer can migrate to the molecular chain breakage site during recycling to carry out chemical repair and restore the material's mechanical properties. The modified PEGDA forms a surface cross-linking layer through UV curing, and laser engraving can replace ink printing to form a clear logo, avoiding the generation of foreign objects, improving surface wear resistance and laser engraving clarity, so that the pickball can still maintain excellent impact strength, elongation at break, and surface properties after multiple cycles. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0021] Figure 1 This is a flowchart of the manufacturing method in this invention; Figure 2 This is a schematic diagram of the control group A pickball in this invention; Figure 3 This is a schematic diagram of the pickballs in experimental group A of this invention; Figure 4 This is a schematic diagram of the control group B pickball in this invention; Figure 5 This is a schematic diagram of the pickballs in experimental group B of this invention. Detailed Implementation

[0022] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0023] In the description of this invention, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component positioned centrally in the connection.

[0024] Example 1: A recyclable pickball in this embodiment includes a sphere, characterized in that the sphere is made of functionalized TPAE (thermoplastic polyamide ester), modified epoxy functionalized acrylic polymer and modified PEGDA (polyethylene glycol diacrylate), and the sphere is marked by laser engraving.

[0025] Example 2: Please see Figure 1 This embodiment describes a method for manufacturing recyclable pickles. The preparation method for the aforementioned pickles includes the following steps: Step S1: Mix functionalized TPAE, modified epoxy-functionalized acrylic polymer and modified PEGDA to obtain a mixture; Step S2: Extrude the mixture through an extruder to obtain composite granules; Step S3: The composite particles are injection molded into spheres, and then the logo is engraved on the spheres using laser engraving to obtain Peak balls.

[0026] It should also be noted that the pick balls prepared by the above method are crushed in a liquid nitrogen low-temperature environment after being discarded, and recycled material fragments with a particle size of less than 3 mm are obtained. The recycled material can be used in the preparation process of step S3 to obtain new pick balls. Furthermore, the recycled material can be directly used for injection molding under the action of functionalized TPAE, modified epoxy functionalized acrylic polymer and modified PEGDA, without the need to add new materials or additives.

[0027] Specifically, in step S1, functionalized TPAE, modified epoxy-functionalized acrylic polymer and modified PEGDA are mixed to obtain a mixture; Step S1 specifically includes the following steps: Step S11: Functionalized TPAE with a particle size of 20-40 mesh, modified epoxy-functionalized acrylic polymer and modified PEGDA are mixed at room temperature to obtain a mixture. In step S11, the mass percentages of functionalized TPAE, modified epoxy-functionalized acrylic polymer, and modified PEGDA in the mixture are 80%, 10%, and 10%, respectively, and the mixing time is 15-20 min with a rotation speed of 200-400 rpm; preferably, the mass percentages of functionalized TPAE, modified epoxy-functionalized acrylic polymer, and modified PEGDA in the mixture are 75-85%, 8-12%, and 7-15%, respectively, and the mixing time is 18 min with a rotation speed of 300 rpm.

[0028] It is known that by dry mixing the three materials with the same particle size and using mechanical shearing to ensure uniform distribution of each material within 15-20 minutes, a foundation is laid for the subsequent melting reaction, which is conducive to efficient physical and chemical bonding in subsequent steps.

[0029] It should be noted that uniformly dispersing the various materials to obtain a mixture can reduce performance fluctuations caused by local component enrichment and provide uniform starting conditions for subsequent vacuum drying, extrusion reactions, and grafting, thereby improving product consistency and mechanical property uniformity.

[0030] It should also be noted that by uniformly dispersing the proportions corresponding to each material, the batch-to-batch variation of materials is reduced, and local stress concentration is avoided, thereby mitigating problems such as brittle fracture and mold filling defects caused by phase separation and unevenness. In addition, uniform particle size and sufficient premixing can reduce agglomerates or phase separation caused by local overheating or poor mixing during subsequent extrusion.

[0031] Step S12: After drying the mixture in a vacuum environment, cool it to room temperature, place the mixture on a vibrating screen for dispersion, and then seal and let it stand to obtain the mixture.

[0032] In step S12, the drying temperature is 70-90℃, the time is 3-5h, the vacuum degree of the vacuum environment is (-0.1)-(-0.09)MPa, the mesh size of the vibrating screen is 20-40 mesh, and the sealing and standing time is 6-10h; preferably, the drying temperature is 80℃, the time is 4h, the vacuum degree of the vacuum environment is -0.095MPa, the mesh size of the vibrating screen is 20 mesh, and the sealing and standing time is 8h.

[0033] It should be noted that by drying the mixture in a vacuum environment, adsorbed moisture and volatile solvents in the mixture can be removed. Subsequent cooling and sieving can achieve re-grading and de-agglomeration of the mixed particles. Sealing and standing allows the internal stress of the material particles to be released and the moisture content and dispersion state to be stabilized.

[0034] It should also be noted that step S12 reduces moisture and volatiles in the mixture and improves mixing uniformity and flow stability. Since polyamide ester and epoxy functional groups are sensitive to moisture, drying can avoid side reactions and reduce bubbles, chain breaks, and poor rheology generated during melt processing. After cooling, the mixture is de-agglomerated and reclassified by a 20-mesh vibrating screen, which ensures the uniformity of subsequent feeding and reduces melt instability or local overheating caused by feeding fluctuations in step S2. This improves the mixing and reaction uniformity of the subsequent co-rotating twin-screw extruder. Sealing and allowing the mixture to stand allows the internal stress to be released and the moisture content and dispersion state to be stabilized, preventing re-hygroscopicity or re-agglomeration in a short time. It also facilitates the further dissipation of residual volatiles on the particle surface, helping to ensure that the physical state, moisture content, and internal stress of the material are in a controllable and stable state when the mixture enters step S2, so that a reliable chemical reaction and dispersion effect can be obtained during reactive extrusion.

[0035] The modified epoxy-functionalized acrylic polymer is obtained according to the following steps: Functionalized TPAE particles are placed in acetone at 60-70℃ and stirred to swell for 1.5-2 hours to obtain the first solution a; preferably, functionalized TPAE particles are placed in acetone at 60℃ and stirred to swell for 2 hours to obtain the first solution a, thereby relaxing the functionalized TPAE molecular chain segments. GMA (glycidyl methacrylate) monomer and a free radical initiator are added to the first solution a, and the reaction is carried out at 70-80°C for 4-6 hours to obtain the second solution a; the free radical initiator is AIBN (azobisisobutyronitrile), and the GMA monomer polymerizes under the action of the free radical initiator and is simultaneously grafted onto the swollen functionalized TPAE molecular chain; preferably, the reaction is carried out at 75°C for 5 hours to obtain the second solution a; The second solution a was mixed with ethanol to obtain a precipitate, and the precipitate was washed with ethanol to obtain an intermediate; the homopolymer and unreacted monomers could be removed by washing with ethanol. The intermediate was embrittled in liquid nitrogen and then ground at low temperature to obtain a modified epoxy-functionalized acrylic polymer.

[0036] It should be noted that the modified epoxy-functionalized acrylic polymer is a granular modified product obtained by grafting epoxy groups onto the surface of functionalized TPAE. The modified epoxy-functionalized acrylic polymer has TPAE as the core and a layer of GMA copolymer grafted onto the TPAE surface as the shell to form a core-shell structure. In addition, the grafting rate of the modified epoxy-functionalized acrylic polymer is 8%-15%, which can be calculated and controlled by titrating the epoxy value. It is understood that the methods of obtaining and controlling the grafting rate are well known to those skilled in the art and will not be described in this embodiment.

[0037] It is known that modified epoxy-functionalized acrylic polymers, by grafting epoxy functional groups from GMA onto the surface of functionalized TPAEs, can chemically react with the nucleophilic end groups (such as amine and carboxyl groups) of functionalized TPAEs when melted. The resulting pickles can provide chemical repair functions for recycling after the material is recycled through the epoxy groups of the modified epoxy-functionalized acrylic polymer, thereby solving the performance degradation caused by molecular chain breakage during recycling of existing pickles.

[0038] It is important to emphasize that, when pick balls containing modified epoxy-functionalized acrylic polymers are recycled, the epoxy groups in the modified epoxy-functionalized acrylic polymers can precisely migrate to the phase interface or molecular chain breakage site for effective repair with high repair efficiency. At the same time, the core-shell structure of the modified epoxy-functionalized acrylic polymers ensures the uniform distribution of epoxy groups, avoids agglomeration, and enhances stability. This ensures that the impact strength and elongation at break of pick balls containing modified epoxy-functionalized acrylic polymers are maintained during multiple recycling, thereby improving recyclability.

[0039] It should also be noted that the modified epoxy-functionalized acrylic polymer enhances the performance of pickles during recycling through chemical and physical means. In particular, during high-temperature processing, the modified epoxy-functionalized acrylic polymer partially restores the molecular chain connectivity and structural integrity through the reaction of epoxy groups with functionalized TPAE, ensuring that waste pickles can maintain high mechanical properties and durability during recycling. In addition, in the existing pickle recycling process, repeated heat treatment can cause the material's molecular chains to break, leading to a decline in mechanical properties. However, the introduction of the modified epoxy-functionalized acrylic polymer can effectively alleviate this problem, allowing pickles containing the modified epoxy-functionalized acrylic polymer to maintain high mechanical properties even after multiple cycles.

[0040] It is worth noting that the recycled material can maintain good mechanical properties through epoxy repair during recycling, and can withstand multiple cycles. The impact strength and elongation at break can also be guaranteed. At the same time, under the action of modified epoxy-functionalized acrylic polymer, the recycled material can maintain good fluidity in subsequent cycles, making it suitable for processing under high shear conditions, and will not cause insufficient mold filling or shrinkage due to performance degradation.

[0041] Modified PEGDA is obtained according to the following steps: EVA (ethylene-vinyl acetate copolymer) is melted under nitrogen atmosphere at 90-100°C, followed by the addition of PEGDA and a catalyst for 30-45 min; preferably, EVA is melted under nitrogen atmosphere at 95°C, followed by the addition of PEGDA and a catalyst for 40 min; during this process, the terminal acrylate groups of PEGDA undergo transesterification with some of the vinyl acetate groups on the EVA chain, grafting PEGDA segments onto the EVA backbone; the catalyst is dibutyltin dilaurate, and the amount of catalyst added is 0.5%-1% of the mass of EVA; After the reaction is complete, a terminator is added, and the mixture is granulated using an underwater pelletizer to obtain EVA-g-PEGDA (polyethylene glycol diacrylate grafted ethylene-vinyl acetate copolymer) prepolymer particles; the terminator is 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy radical, and the amount of terminator added is 0.1%-0.3% of the mass of EVA; EVA-g-PEGDA prepolymer particles are blended with a photoinitiator in a single-screw extruder at a temperature of 70-80°C, and then cooled and granulated to obtain modified PEGDA. Preferably, EVA-g-PEGDA prepolymer particles are blended with a photoinitiator in a single-screw extruder at a temperature of 80°C. The photoinitiator is 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, and the amount of photoinitiator added is 1%-3% of the mass of PEGDA monomer.

[0042] It should be noted that modified PEGDA introduces acrylic (acryloyl) groups into the main chain or side chain of EVA through chemical grafting, which can form a cross-linked layer during the subsequent UV curing process. This allows the modified PEGDA to endow the prepared peak balls with good wear resistance and scratch resistance, and also makes the surface of the peak balls have good laser engraving properties.

[0043] It is important to emphasize that the preparation of pickles by modifying PEGDA and using UV curing can replace the ink printing used in existing pickles. This allows recycled materials to maintain good surface properties while avoiding defects caused by ink. It solves the problem that ink printing can form foreign objects during the recycling process of existing pickles, leading to stress concentration sources and a decline in mechanical properties.

[0044] It is known that the cross-linked layer formed by modified PEGDA and subsequent UV curing enhances the wear resistance and scratch resistance of the peak ball surface, making it suitable for multiple cycles of use. By replacing ink printing with photocuring cross-linking, foreign matter points generated in existing recycled materials are eliminated, maintaining uniformity and mechanical properties. At the same time, the PEG segments and EVA segments in modified PEGDA can slowly and controllably migrate to the surface during processing, forming a uniform enrichment layer and improving surface functionality.

[0045] It should also be noted that modified PEGDA can provide photocurable sites during the recycling process, enabling it to quickly crosslink under UV irradiation and form a robust surface structure, thereby improving the surface durability of the recycled material. Through the combination of UV curing and laser engraving, the surface performance of recycled pickles can be effectively improved, avoiding the brittleness enhancement caused by the instability of the recycled material's performance, thus solving the problem of reduced wear resistance and surface strength of existing recycled materials after multiple thermal cycles.

[0046] It is worth noting that the cross-linked network formed by UV curing enhances the surface hardness and toughness, enabling the recycled material to retain good mechanical properties after multiple cycles. In addition, the photocuring replaces the ink, avoiding the material uniformity problem caused by the ink as an incompatible phase.

[0047] Specifically, in step S2, the mixture is extruded and granulated using an extruder to obtain composite particles; The mixture is placed in a co-rotating twin-screw extruder and passed sequentially through the first, second, third, and fourth zones on the barrel of the co-rotating twin-screw extruder. After the mixture is discharged from the barrel, composite granules are obtained.

[0048] The temperature in the first zone is 155-165℃, the temperature in the second zone is 165-175℃, the temperature in the third zone is 170-180℃, and the temperature in the fourth zone is 175-185℃. The screw speed of the twin-screw extruder is 200-300 rpm. Preferably, the temperature in the first zone is 160℃, the temperature in the second zone is 170℃, the temperature in the third zone is 175℃, the temperature in the fourth zone is 180℃, and the screw speed of the twin-screw extruder is 250 rpm.

[0049] It should be noted that co-rotating twin-screw extrusion provides strong dispersion and mixing, effectively dispersing the three materials mentioned above in the melt and avoiding coarse phase separation. By preparing composite granules through a co-rotating twin-screw extruder, melting, mixing, chemical coupling (epoxy ring opening and grafting), and devolatilization (volatile matter degassing) can be completed in a continuous process, improving efficiency and ensuring batch consistency. Furthermore, the different temperatures of the first, second, third, and fourth zones reduce the risk of thermal degradation while promoting the required chemical reactions. The composite granules obtained after extrusion granulation have both modified functional sites and a good dispersion state, which facilitates subsequent injection molding and UV curing processes.

[0050] It should also be noted that functionalized TPAE can become the continuous phase or main phase in the molten state at 160-180℃. The functionalized TPAE contains end groups that can react with epoxy (such as hydroxyl, carboxyl or amine, other nucleophilic end groups), which ensures the mechanical properties of the prepared pickballs. Under high shear and high temperature conditions, the epoxy groups on the modified epoxy-functionalized acrylic polymer spontaneously migrate to the phase interface and the broken and terminal positions of the functionalized TPAE. Under melt conditions, the epoxy undergoes thermal ring-opening and reacts with nucleophilic groups (functionalized TPAE end groups) to form covalent coupling or chain extension, which partially restores or increases the molecular weight, increases the interfacial adhesion, and makes the fine phase more difficult to separate. Modified PEGDA is dispersed in the functionalized TPAE in the extrusion zone as particles or fine phase. Its acrylic groups usually do not undergo significant thermal polymerization during the hot extrusion stage, but the EVA segments have good compatibility with the functionalized TPAE and achieve dispersion and partial interpenetration. The modified PEGDA retains photocuring activity and the potential to migrate to the surface in the composite particles after extrusion, and is used for UV curing in step S3.

[0051] It is known that the composite particles obtained through step S2 have undergone partial coupling and grafting at the chemical level and achieved fine phase dispersion at the physical level. This results in the composite particles exhibiting more stable melt rheology, higher injection molding consistency, and enhanced mechanical properties, reducing the performance degradation problem caused by simply melting and re-granulating recycled materials.

[0052] Specifically, in step S3, the composite particles are injection molded into spheres, and then a logo is engraved on the spheres using laser engraving to obtain a Peak ball.

[0053] Step S3 includes the following steps: Step S31: After placing the composite granules into the injection molding machine, the molten material is injected into the spherical cavity mold through the injection molding machine. After the molten composite granules cool and solidify, the preform is obtained. In step S31, the injection molding machine has a melt temperature of 185-190℃, an injection pressure of 60-80MPa, a holding pressure of 40-50MPa, and a holding time of 10-15s; preferably, the injection molding machine has a melt temperature of 185℃, an injection pressure of 70MPa, a holding pressure of 45MPa, and a holding time of 12s.

[0054] It should be noted that the high temperature and pressure provided by injection molding facilitate the thermal reaction of residual epoxy (ring-opening and binding with the nucleophilic end groups of functionalized TPAE), further completing chemical coupling and chain extension, resulting in more stable mechanical properties of the preform. At the same time, under the high temperature, high pressure and shear conditions of injection molding, the epoxy groups on the modified epoxy functionalized acrylic polymer continue to be positioned and undergo thermochemical reactions with the functionalized TPAE (or solidify into a more stable coupling structure after cooling), which macroscopically manifests as an improvement in the impact strength, elongation and fatigue life of the preform. In addition, the compatibility between EVA segments and functionalized TPAE in the melt after melting allows the melt to be controllably enriched on the surface during the cooling stage, forming a surface layer rich in acrylic sites.

[0055] Step S32: Place the preform in a UV curing oven. After curing, use a fiber laser engraving machine to engrave the markings on the surface of the preform to obtain a Peak ball.

[0056] In step S32, the UV curing oven irradiation time is 60-90 seconds, the UV wavelength is 365 nm, and the UV light intensity is 50-100 mW / cm². 2Preferably, the UV curing oven has an irradiation time of 85 seconds, a UV wavelength of 365 nm, and an ultraviolet light intensity of 80 mW / cm². 2 .

[0057] It should be noted that the surface of the preform is photocured using a wavelength of 365nm and an irradiation time of 85s. This triggers the free radical polymerization of the acrylic groups in the modified PEGDA in the presence of a photoinitiator, forming a surface and near-surface cross-linked network to improve the wear resistance, scratch resistance, and adhesion of the marking layer on the surface of the Peak ball. The marking is then engraved on the cured surface of the ball using a fiber laser engraving machine without the use of ink. This avoids the stress concentration and embrittlement problems caused by foreign ink particles during recycling from the source, and the laser-engraved marking is wear-resistant and durable.

[0058] It should also be noted that during UV curing, the cross-linked polyethylene glycol diacrylate provides hardness, while EVA provides toughness. The interpenetration of the two ensures adhesion and crack resistance. After UV curing, fiber laser engraving is performed, and the markings on the surface of the sphere are part of the cured layer, not ink adhesion, thus avoiding the problem of foreign matter points during recycling.

[0059] In application, after obtaining recyclable pickballs through steps S1-S3, the pickballs are used as the experimental group recycled material, and the pickballs prepared by the traditional method are used as the control group recycled material for multiple recycling, and the data reflecting the mechanical properties of the two are detected. Table 1 shows the mechanical properties of the experimental group and the control group recycled materials after different number of cycles.

[0060] In the above tests, impact strength was tested according to ASTM D256, elongation at break according to ASTM D638, melt flow index according to ASTM D1238, and abrasion loss according to ASTM D1044. It is understood that the above test methods and standards are well known to those skilled in the art, and will not be described in detail in this embodiment. Control group A is as follows: Figure 2 As shown, experimental group A is as follows: Figure 3 As shown, control group B is as follows: Figure 4 As shown, experimental group B is as follows: Figure 5 As shown.

[0061] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A recyclable pickball, comprising a sphere, characterized in that, The sphere is made of functionalized TPAE, modified epoxy-functionalized acrylic polymer and modified PEGDA, and the sphere is marked by laser engraving.

2. A manufacturing method of a recyclable petanque ball, characterized in that, The preparation method is used for the pickballs according to claim 1, and the preparation method includes the following steps: Step S1: Mix functionalized TPAE, modified epoxy-functionalized acrylic polymer and modified PEGDA to obtain a mixture; Step S2: Extrude the mixture through an extruder to obtain composite granules; Step S3: The composite particles are injection molded into spheres, and then the logo is engraved on the spheres using laser engraving to obtain Peak balls.

3. The method for manufacturing recyclable pickles according to claim 2, characterized in that, Step S1 specifically includes the following steps: Step S11: Functionalized TPAE, modified epoxy-functionalized acrylic polymer and modified PEGDA of the same particle size are mixed at room temperature to obtain a mixture. Step S12: After drying the mixture in a vacuum environment, cool it to room temperature, place the mixture on a vibrating screen for dispersion, and then seal and let it stand to obtain the mixture.

4. The method for manufacturing recyclable pickles according to claim 3, characterized in that, In step S11, the mass percentages of functionalized TPAE, modified epoxy-functionalized acrylic polymer, and modified PEGDA in the mixture are 75-85%, 8-12%, and 7-15%, respectively, and the mixing time is 15-20 min and the mixing speed is 200-400 rpm. In step S12, the drying temperature is 70-90℃ and the time is 3-5h, the vacuum degree of the vacuum environment is (-0.1)-(-0.09)MPa, the mesh size of the vibrating screen is 20-40 mesh, and the sealing and standing time is 6-10h.

5. The method for manufacturing recyclable pickles according to claim 3, characterized in that, The modified epoxy-functionalized acrylic polymer is obtained according to the following steps: Functionalized TPAE particles were placed in acetone at 60-70℃ and stirred to swell for 1.5-2 hours to obtain the first solution a. GMA monomer and free radical initiator were added to the first solution a and reacted at 70-80℃ for 4-6 hours to obtain the second solution a; The second solution a was mixed with ethanol to obtain a precipitate, and the precipitate was washed with ethanol to obtain an intermediate. The intermediate was embrittled in liquid nitrogen and then ground at low temperature to obtain a modified epoxy-functionalized acrylic polymer.

6. The method for manufacturing recyclable pickles according to claim 3, characterized in that, The modified PEGDA is obtained according to the following steps: EVA was melted in a nitrogen atmosphere at 90-100°C, and then PEGDA and catalyst were added and reacted for 30-45 minutes. After the reaction is complete, a terminator is added, and the mixture is granulated using an underwater pelletizer to obtain EVA-g-PEGDA prepolymer particles. EVA-g-PEGDA prepolymer particles were blended with a photoinitiator in a single-screw extruder at a temperature of 80°C, and then cooled and granulated to obtain modified PEGDA.

7. The method for manufacturing recyclable pickles according to claim 2, characterized in that, The mixture is placed in a co-rotating twin-screw extruder and passed sequentially through the first, second, third, and fourth zones on the barrel of the co-rotating twin-screw extruder. After the mixture is discharged from the barrel, composite granules are obtained.

8. The method for manufacturing recyclable pickles according to claim 7, characterized in that, The temperature of the first zone is 155-165℃, the temperature of the second zone is 165-175℃, the temperature of the third zone is 170-180℃, the temperature of the fourth zone is 175-185℃, and the screw speed of the twin-screw extruder is 200-300 rpm.

9. The method for manufacturing recyclable pickles according to claim 2, characterized in that, Step S3 includes the following steps: Step S31: After placing the composite granules into the injection molding machine, the molten material is injected into the spherical cavity mold through the injection molding machine. After the molten composite granules cool and solidify, the preform is obtained. Step S32: Place the preform in a UV curing oven. After curing, use a fiber laser engraving machine to engrave the markings on the surface of the preform to obtain a Peak ball.

10. The method for manufacturing recyclable pickles according to claim 9, characterized in that, In step S31, the injection molding machine has a melt temperature of 185-190℃, an injection pressure of 60-80MPa, a holding pressure of 40-50MPa, and a holding time of 10-15s. In step S32, the irradiation time of the UV curing oven is 60-90 seconds, the UV wavelength is 365 nm, and the UV light intensity is 50-100 mW / cm². 2 .

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