Convertible nursery container system for secondary use of paper cups, biodegradable barrier coating composition and nursery kit

Abstract

The application discloses a paper cup secondary utilization convertible seedling container system, a biodegradable barrier coating composition and a seedling kit, and belongs to the technical fields of one-time beverage paper cup secondary utilization, water-based fluorine-free biodegradable barrier coating and horticultural seedling technology. The system integrates store recycling pretreatment, coffee residue substrate and digital traceability modules, and realizes the full life cycle of paper cup closed loop. The core technology adopts a specific bio-based compound barrier coating and an activated drainage structure. Compared with traditional market products, the scheme can realize the same or even better heat-resistant liquid sealing performance with an optimized coating thickness, completely solve the technical problems of poor water resistance or brittleness of single degradation material, and fully meet the composting degradation requirements. The application not only guarantees food contact safety, but also significantly improves the recycling value of waste resources, and provides a low-carbon, compliant and efficient green solution for the industry.

Description

Technical Field

[0001] This invention belongs to the fields of disposable beverage paper cup reuse, water-based fluorine-free biodegradable barrier coating, and horticultural seedling technology. Specifically, it relates to a convertible seedling container system for the reuse of paper cups, a biodegradable barrier coating composition, and a seedling kit. Background Technology

[0002] Disposable beverage paper cups are used in large quantities in retail settings, but existing recycling systems often struggle to establish stable resource recovery pathways due to residual liquid contamination, mixed disposal, and varying end-of-life treatment conditions. Furthermore, consumer participation in recycling often lacks tangible rewards, hindering the formation of a closed loop. On the other hand, coffee brewing in stores generates large amounts of coffee grounds, which, without proper stabilization, are prone to spoilage, producing unpleasant odors and raising hygiene concerns.

[0003] In the current field of horticultural seedling containers, various paper-based or biodegradable planting container solutions have been disclosed. Their focus is primarily on the convenience of cultivation and transplanting, but they lack systematic integration with aspects such as heat-resistant liquid sealing safety during beverage serving, hygiene control of residual liquid pretreatment at the store level, and user-end kit-based distribution traceability. Other existing technologies involve drainage perforation structures for cup-type planting containers, but they do not simultaneously address the compatibility design between sealing hot beverages in the first use stage and mechanically activated drainage in the second use stage, nor do they systematically integrate with closed-loop store operations.

[0004] In the field of paper cup barrier coatings, a variety of water-based biodegradable barrier systems have been disclosed. Existing disclosures mostly focus on paper-based barrier and heat-sealing performance, but they do not adequately cover the conflicting needs of the cup bottom structure in the two life stages of the same paper cup: the first stage of use requires sealing of the cup bottom liquid and prevention of hot beverage leakage; the second stage of use requires convenient activation of drainage and maintenance of seedling aeration and drainage, and also needs to form a closed-loop operation in conjunction with the pretreatment of residual liquid at the store, kit distribution and traceability incentives.

[0005] Regarding the resource utilization of coffee grounds, there are already public reports on using coffee grounds as a matrix component, but most focus on the materialization or matrix formation of coffee grounds themselves, lacking a synergistic design with the direct secondary use of paper cups with activated drainage structures and the closed-loop operation of stores. Therefore, there are still gaps between existing solutions such as material replacement or single-point recycling, paper cup or paper container plant reuse structures, water-based biodegradable barrier coatings, and coffee grounds-based seedling substrates, making it difficult to simultaneously address: the liquid-tight safety of beverage containers in the first use stage, the controllable drainage and aeration requirements of seedling containers in the second use stage, and the closed-loop goal of end-of-life composting or soil return and collaborative operation with stores and users. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a convertible seedling container system for the reuse of paper cups, a biodegradable barrier coating composition, and a seedling kit.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] This invention provides a convertible seedling container system for the reuse of paper cups. The system transforms used disposable beverage paper cups into seedling cups after a first usage phase. The used disposable beverage paper cups are converted seedling cups with a biodegradable barrier coating and an activated drainage structure. In the first usage phase, they serve as beverage containers; in the second usage phase, after drainage activation, they function as seedling cups. The system includes: a diversion and recycling module for receiving and diverting the used disposable beverage paper cups; and a residual liquid control and pretreatment module for performing one or more of the following treatments on the used disposable beverage paper cups: residual liquid removal, rinsing, wiping, drying, and disinfection. The module ensures that the inner surface of the used disposable beverage paper cups is in a dry state suitable for filling with seedling substrate. The dry state is defined as having no visible water film on the inner surface of the paper cup and residual moisture ≤ 0.30 g / cup. The specific value of residual moisture ≤ 0.30 g / cup can be 0.01 g / cup, 0.05 g / cup, or 0.10 g / cup. The formula includes: a cup size of 0.15g / cup, 0.18g / cup, 0.20g / cup, 0.22g / cup, 0.23g / cup, 0.25g / cup, 0.28g / cup, and 0.30g / cup; a drainage activation and seedling filling module, used to activate the drainage structure to form a drainage channel under the constraint of a positioning pressure head or limiting tool, and to fill the used disposable beverage paper cup with seedling substrate and seeds; a kit distribution module, used to provide individually packaged substrate components and seed modules; a user interaction and traceability module, including one or more of a barcode scanning terminal, near field communication (NFC) reader / writer terminal, or radio frequency identification (RFID) reader / writer terminal, used to record information including at least the paper cup batch, store identification, recycling time, pretreatment status, kit type, and user operation record through interactive identification, and output planting guidance information; and a composting or soil return module, used to output composting or soil degradation information of the seedling cups after seedling cultivation.

[0009] The diversion and recycling module includes a limiting structure, an anti-misdispensing structure, a flow guiding structure, or a visual prompting structure; the residual liquid control and pretreatment module includes a residual liquid volume determination structure, as well as one or more of the following: a rinsing table or spraying structure, a water absorption or draining structure, a wiping structure, a hot air drying structure or a room temperature air drying structure, a disinfection structure, and a sealed temporary storage structure; the drainage activation and seedling filling module includes a positioning pressure head or a limiting tooling, used to ensure that the activation operation occurs at a preset position and improve activation consistency; the kit dispensing module further provides a biodegradable base or flow guiding tray to receive exudate, used for exudate management and secondary irrigation during the seedling stage.

[0010] This invention provides a conversion seedling cup, which is a disposable beverage paper cup in the above-mentioned system and is suitable for holding beverages in the first use stage and for use as a seedling container in the second use stage. The conversion seedling cup includes: a paper-based cup body, including a cup body and a cup bottom; and a biodegradable barrier coating disposed on the inner surface of the paper-based cup body. The biodegradable barrier coating is a continuous film layer formed by an aqueous coating composition. The biodegradable barrier coating contains a polyhydroxyalkanoate (PHA) film-forming component and a polyvinyl alcohol (PVA) dispersion stabilizing component, and the mass ratio of PHA to PVA in the biodegradable barrier coating is ≥6:1 by solids weight; the specific value of the mass ratio can be 6:1, 6.1:1, or 6. 5:1, 7:1, 8:1, 10:1, 12:1, 12.5:1, 12.9:1, 15:1, 16.8:1, 20:1, 30:1, 50:1, 80:1, 100:1, 200:1, 500:1, 952:1, or 1000:1; An activated drainage structure is set at the bottom of the cup, the activated drainage structure includes a preset weakening zone and a sealing part, the preset weakening zone is a combination of a laser micropore array zone and a concentric ring weakening zone, the concentric ring weakening zone is provided with 3 to 8 discontinuous connection points along the circumference; the number of discontinuous connection points can specifically be 3, 4, 5, 6, 7, or 8; the sealing part is a biodegradable sealing coating located in the preset weakening zone, and the... The sealing coating and the biodegradable barrier coating are formed from the same water-based coating composition. In the first stage of use, the sealing portion covers or seals the preset weakened area and, together with the biodegradable barrier coating, forms a bottom liquid seal structure. The mass loss rate of the sealing portion after immersion in pure water at 25°C for 24 hours is ≤5%. The specific value of the mass loss rate can be 0.1%, 0.5%, 1.0%, 1.2%, 1.5%, 1.8%, 1.9%, 2.0%, 2.1%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, 4.7%, or 5.0%. In the second stage of use, the preset weakened area is subjected to an external force of 10N to 15N through pressing, puncturing, tearing, or a pull-ring opening operation. The sealed state is transformed into a drainage state to form no less than three drainage channels connecting the inside of the cup to the outside. The specific value of the external force can be 10N, 10.2N, 10.5N, 10.8N, 11N, 11.2N, 11.5N, 11.8N, 12N, 12.2N, 12.5N, 12.8N, 13N, 13.2N, 13.5N, 14N, 14.2N, 14.5N, 14.8N, or 15N. The specific number of drainage channels can be 3, 4, 5, 6, 8, or more. After activation, the sealing part remains connected to the bottom of the cup to form a folding piece or folding ring, and the mass of the detached fragments is ≤5mg. The specific value of the detached fragment mass can be 0mg, 0.1mg, or 0.2mg, 0.3mg, 0.4mg, 0.5mg, 0.6mg, 1.0mg, 2.0mg, 3.0mg, 4.0mg, or 5.0mg.

[0011] The biodegradable barrier coating is a continuous film layer formed by coating and drying an aqueous coating composition; the biodegradable barrier coating contains a PHA film-forming component and a PVA dispersion stabilizing component; the PHA film-forming component is formed by PHA aqueous emulsion or by compounding PHA with at least one biodegradable film-forming component; and, based on solid mass, the mass ratio of PHA to PVA in the biodegradable barrier coating is ≥6:1; the specific value of the mass ratio can be 6:1, 6.1:1, 7:1, 8:1, 10:1, 12:1, 12.5:1, 12.9:1, 15:1, 16.8:1, 20:1, 30:1, 40:1, 50:1, 60:1, 70:1, 80:1, 100:1, 200:1, 500:1, 800:1, 952:1, etc.

[0012] The biodegradable barrier coating meets one or more of the following properties: when exposed to hot water at 95°C for 30 minutes, its absorbency is ≤13.0 g / m²; the specific absorbency values ​​can be 5.0 g / m², 6.0 g / m², 7.0 g / m², 8.0 g / m², 9.0 g / m², 9.8 g / m², 10.0 g / m², 10.5 g / m², 11.0 g / m², 11.2 g / m², 11.5 g / m², 12.0 g / m², 12.5 g / m², 12.8 g / m², 12.9 g / m², 13.0 g / m², etc. m², etc.; after containing 200 mL of hot water at an initial temperature of 95℃ and letting it stand for 4 hours, the leakage of the cup body is 0 mg; and under the migration conditions of using 10 wt% ethanol aqueous solution as a food simulant and maintaining it at 70℃ for 2 hours, the total migration amount is ≤5.5 mg / dm²; the specific value of the total migration amount can be 1.0 mg / dm², 2.0 mg / dm², 3.0 mg / dm², 3.5 mg / dm², 4.0 mg / dm², 4.5 mg / dm², 4.8 mg / dm², 5.0 mg / dm², 5.2 mg / dm², 5.5 mg / dm², etc.

[0013] The preset weakening zone is selected from the laser micropore array zone, the concentric ring weakening zone, or a combination thereof, and the sealing part remains to cover or close the preset weakening zone during the first use stage to maintain the seal of the liquid at the bottom of the cup.

[0014] The preset weakening zone is a combination of a laser micropore array zone and a concentric annular weakening zone. The concentric annular weakening zone has 3 to 8 discontinuous connection points along its circumference to form at least 3 drainage channels after activation. The specific number of discontinuous connection points can be 3, 4, 5, 6, 7, or 8. The sealing part is a biodegradable sealing coating formed by coating the preset weakening zone and drying it into a film. The sealing coating is formed by a secondary coating and drying of the coating liquid used to form the biodegradable barrier coating on the preset weakening zone. The drainage structure to be activated further includes a pull-ring type activation component or a press-and-break type activation component. The activation breaking force of the activation operation is 10N to 15N, and after activation, the sealing part remains connected to the bottom of the cup, forming a folded flap or folded ring to reduce the risk of fragment detachment. The specific value of the activation breaking force can be 10N, 10.2N, 10.5N, 10.8N, 11N, or 11.2N. 11.5N, 11.8N, 12N, 12.2N, 12.5N, 12.8N, 13N, 13.2N, 13.5N, 14N, 14.5N, 14.8N, 15N, etc.; the fragment shedding mass is ≤5mg, for example, it can be 0.1mg, 0.2mg, 0.3mg, 0.4mg, 0.5mg, 0.6mg, 0.8mg, 1.0mg, 1.2mg, 1.5mg, 2.0mg, 3... 0.0mg, 4.0mg, 5.0mg, etc.; the mass of the detached fragments is determined by the following method: the activated empty cup is inverted and fixed so that the height of the bottom of the cup from the surface of the pre-constantly weighed paper base is 50mm. A rubber hammer with a hammer weight of 200g is released freely from 100mm above the outer surface of the bottom of the cup to strike the center of the pre-set weakened area at the bottom of the cup. This is repeated 10 times. The detached fragments are collected and the mass increment of the paper base is weighed. The mass increment is the mass of the detached fragments.

[0015] The outer surface of the paper-based cup body is provided with a conversion prompt label, which includes an interactive label, such as a QR code, barcode, near-field communication tag, or radio frequency identification tag. When the interactive label is a near-field communication tag or radio frequency identification tag, the tag is a detachable structure or is set on an outer sleeve that is detachably connected to the paper-based cup body. The conversion seedling cup is a biodegradable structure suitable for composting disposal. The conversion seedling cup as a whole includes a paper-based cup body, a biodegradable barrier coating, and cup body seams. The adhesive and outer surface printing ink have a disintegration rate ≥92.5% after 45 days and a biodegradation rate ≥88.5% after 90 days under aerobic controlled composting conditions at 58℃; the total organic fluorine content of the paper-based cup body, biodegradable barrier coating, adhesive and printing ink is ≤5mg / kg; the total organic fluorine content can be any value among 0.1mg / kg, 0.5mg / kg, 1.0mg / kg, 2.0mg / kg, 3.0mg / kg, 4.0mg / kg and 5.0mg / kg.

[0016] This invention provides a seedling kit, comprising: a conversion seedling cup, which is the conversion seedling cup in the above-mentioned system; a substrate component, which is individually packaged and contains a compound of stabilized coffee grounds obtained by water washing, heat treatment, and then drying, and a seedling substrate, wherein the moisture content of the stabilized coffee grounds is ≤10%, and the specific value of the moisture content can be 1%, 2%, 5%, 8%, 9.0%, 9.2%, 9.5%, or 10%; the conductivity of the water extract of the stabilized coffee grounds is ≤1.5 mS / cm, and the specific value of the conductivity can be 0.1 mS / cm, 0.5 mS / cm, 1.0 mS / cm, 1.2 mS / cm, 1.3 mS / cm, 1.4 mS / cm, or 1.5 mS / cm; and the mass fraction of soluble solids in the water extract is ≤3.0%, and the specific value of the mass fraction of soluble solids can be 0.5% or 1%. The components are: 0%, 1.5%, 2.0%, 2.4%, 2.5%, 2.8%, or 3.0%; the volume fraction of stabilized coffee grounds in the substrate component is 3% to 20%, and the specific value of the volume fraction can be 3%, 4%, 5%, 8%, 10%, 12%, 15%, 18%, or 20%; the seedling substrate is selected from one or more of coconut coir, perlite, or vermiculite; the seed module contains one or more plant seeds and a biodegradable carrier; the planting guidance component is used to provide sowing depth, watering frequency, and light parameters; the activation tool component is one or more of a positioning pressure head, a disposable pressing needle, or a limiting tool, used to standardize and activate the preset weakened area of ​​the drainage structure to be activated in the conversion seedling cup to form a drainage channel; the seepage management component is a biodegradable base or a diversion tray, used to collect the seepage during the seedling stage and for secondary irrigation.

[0017] The stabilized coffee grounds are obtained through water washing, heat treatment, and then drying. The water washing process reduces the content of soluble small molecules in the coffee grounds, and the heat treatment is dry heat, steam, or a combination thereof. The moisture content of the stabilized coffee grounds is ≤10%, for example, 1%, 2%, 5%, 8%, 9.2%, 10%, etc. The conductivity of the aqueous extract of the stabilized coffee grounds is ≤1.5 mS / cm, for example, 0.5 mS / cm, 0.8 mS / cm, 1.0 mS / cm, 1.2 mS / cm, etc. The concentration of soluble solids in the water extract is ≤3.0%, for example, 0.5%, 1.0%, 2.0%, 2.4%, 2.5%, 3.0%, etc.; the volume fraction of stabilized coffee grounds in the substrate component is 3% to 20%; the specific value of the volume fraction can be 3%, 4%, 5%, 6%, 8%, 10%, 12%, 15%, 16%, 18%, 20%, etc.; the seedling substrate is selected from one or more of coconut coir, perlite, or vermiculite.

[0018] This invention provides a method for directly reusing used disposable beverage paper cups as seedling cups, comprising the following steps:

[0019] Step 1: After emptying the paper cups of residual liquid at the end of the first stage of use, put them into the diversion and recycling device to collect the recycled paper cups and read the interactive mark on the outer surface of the paper cups to record the batch, store mark and recycling time of the paper cups;

[0020] Step 2: Spray purified water, deionized water, or drinking water into the paper cups recycled in Step 1 using a rinsing station and wipe them. Then, disinfect and dry them to ensure the inner surface of the paper cups is dry. The dry state is defined as having no visible water film on the inner surface of the paper cups and residual moisture ≤ 0.30g / cup. The specific value of residual moisture can be 0.01g / cup, 0.05g / cup, 0.10g / cup, 0.15g / cup, 0.18g / cup, 0.20g / cup, 0.22g / cup, 0.23g / cup, 0.25g / cup, 0.28g / cup, or 0.30g / cup. This yields pre-treated paper cups. Data including at least the pre-treated state and dry state compliance information is then bound and recorded with the interactive identifier.

[0021] Step 3: Place the pre-treated paper cup from Step 2 into a limiting fixture and press the weakened area at the bottom of the cup under an external force of 10N to 15N. The specific value of the external force can be 10N, 10.2N, 10.5N, 11N, 11.5N, 11.8N, 12N, 12.5N, 13N, 13.2N, 13.5N, 14N, 14.5N, or 15N, causing the sealing part to fold over and form no less than 3 drainage channels. After activation, the sealing part remains connected to the bottom of the cup and the mass of the fragments falling off is ≤5mg. The specific value of the mass of the fragments falling off can be 0mg, 0.1mg, 0.2mg, 0.3mg, 0.4mg, 0.5mg, 0.6mg, 1.0mg, 2.0mg, or 5.0mg, resulting in a drainage activated paper cup.

[0022] Step 4: Add the individual packaging matrix component into the paper cup activated by drainage in Step 3 and gently press and level it to obtain the matrix-filled paper cup;

[0023] Step 5: Place the seed module on the surface of the substrate-filled paper cup from Step 4, and cover it with seedling substrate to the predetermined sowing depth to obtain the sowing paper cup;

[0024] Step 6: Water the seeding cups from Step 5 until the substrate is moist, following the planting instructions. Place them in a temperature range of 20℃~30℃ and a light exposure of 12h~16h. The specific temperature values ​​can be 20℃, 21℃, 22℃, 23℃, 24℃, 25℃, 26℃, 27℃, 28℃, 29℃, or 30℃. The specific light exposure time can be 12h, 13h, 14h, 15h, or 16h to obtain seedling cups.

[0025] Step 7: After the seedlings are grown, compost or bury the seedling cups from Step 6 along with the substrate to obtain recycled materials.

[0026] Step 2 includes natural air drying, hot air drying, drying assisted by water-absorbing materials, or a combination thereof; Step 2 uses at least one of ultraviolet light, steam, heat treatment, or ozone for disinfection; in any of steps 1 to 7, the interaction identifier is read and the traceability data record bound to the interaction identifier is written or updated to realize the issuance record, user points, growth check-in, or batch traceability; the traceability data written or updated includes at least the pre-treatment status and dryness status compliance information.

[0027] This invention provides a biodegradable barrier coating composition for convertible seedling cups. The composition is an aqueous system and, based on solid components, comprises: 30-95.2 parts by weight of a film-forming polymer component, wherein the film-forming polymer component contains PHA and optionally further contains at least one biodegradable film-forming polyester; the specific content of the film-forming polymer component can be 30 parts by weight, 35 parts by weight, 40 parts by weight, 42 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, or 80 parts by weight. The content of PVA is any one of 85 parts by weight, 90 parts by weight, 95 parts by weight, and 95.2 parts by weight; the content of PVA is 0.1 to 4.9 parts by weight; the specific content of PVA can be any one of 0.1 parts by weight, 0.5 parts by weight, 1.0 parts by weight, 1.5 parts by weight, 2.0 parts by weight, 2.5 parts by weight, 3.0 parts by weight, 3.5 parts by weight, 4.0 parts by weight, 4.5 parts by weight, and 4.9 parts by weight; the content of the barrier reinforcement component is 0 to 40 parts by weight; the specific content of the barrier reinforcement component can be 0 parts by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, etc. The content of the plasticizer can be any value from 0 parts by weight, 2 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, and 40 parts by weight; the plasticizer component can be 0 to 20 parts by weight; the specific content of the plasticizer component can be any value from 0 parts by weight, 2 parts by weight, 5 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 15 parts by weight, 18 parts by weight, and 20 parts by weight; the crosslinking curing component can be 0 to 5 parts by weight, wherein the crosslinking curing component is selected from silane coupling agents; the specific content of the crosslinking curing component can be 0 parts by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, and 5 parts by weight. The composition contains any value of the following: 0-5 parts by weight of wetting, defoaming, and rheology modifier; the specific content of the wetting, defoaming, and rheology modifier can be any value of 0, 1, 2, 2.5, 3, 4, 4.5, 4.9, or 5 parts by weight; and based on solid mass, the mass ratio of PHA to PVA in the composition is ≥6:1; the total organic fluorine content of the composition is ≤5 mg / kg; and the mass loss rate of the film layer formed by drying the composition and immersing it in pure water at 25°C for 24 hours is ≤5%.

[0028] The PHA is selected from short-chain PHA, medium- and long-chain PHA, or copolymers between monomers forming short-chain PHA and monomers forming medium- and long-chain PHA; the short-chain PHA is selected from one or more of poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB); the medium- and long-chain PHA is selected from poly(3-hydroxyhexanoate), poly(3-hydroxyheptanoate), poly(3-hydroxyoctanoate), poly(3-hydroxynonanoate), and poly(3-hydroxyhexanoate). One or more of poly(3-hydroxydecanoate), poly(3-hydroxyundecanoate), poly(3-hydroxydodecanate), poly(3-hydroxytridecanate), poly(3-hydroxytetradecanoate), and their copolymers or blends; for example, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH); the biodegradable film-forming polyester is selected from one or more of the following: polyester obtained by polycondensation of succinic acid and 1,4-butanediol, polyester obtained by ring-opening polymerization of lactic acid or lactide, polyester obtained by ring-opening polymerization of ε-caprolactone, or combinations thereof; for example, polybutylene succinate (PBS).

[0029] The barrier reinforcement component is selected from nanocellulose, flaky mineral filler, or a combination of the two; wherein the flaky mineral filler is selected from one or more of unmodified kaolin and modified kaolin.

[0030] The composition is prepared by blending a PHA aqueous emulsion with an optional polybutylene succinate aqueous emulsion at a temperature of ≤50°C, and then adding a crosslinking curing component and a barrier reinforcing component after blending at the temperature of ≤50°C; the specific temperature can be 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, etc.

[0031] The wetting, defoaming, and rheology modifiers include alkyl polysaccharide wetting agents, defoamers, and hydroxyethyl cellulose thickeners, and the total organic fluorine content of the composition is ≤5 mg / kg.

[0032] Compared with the prior art, the following significant advantages can be obtained by using the present invention:

[0033] System Integration and Closed-Loop Conversion: The paper cup conversion seedling system provided by this invention realizes the functional transformation of paper cups from "beverage containers" to "seedling containers" through the integration of modules such as diversion and recycling, residual liquid pretreatment, drainage activation and kit distribution. It not only effectively solves the problems of difficult recycling of used paper cups and heavy residual liquid pollution, but also significantly improves the reuse value of waste resources and reduces carbon emissions through closed-loop operation at the store end and user interaction and traceability.

[0034] High-performance fluorine-free barrier coating: The conversion seedling cup and its barrier coating provided by this invention adopt a specific ratio of PHA and PVA compound system, combined with a fluorine-free formula design, successfully solving the technical problems of poor heat resistance, insufficient barrier properties, or high brittleness of single biodegradable materials. The coating maintains excellent liquid-sealing performance (Cobb value ≤ 13.0 g / m², no leakage) in high-temperature (95℃) hot beverage environments, and fully meets food contact safety requirements (total migration ≤ 5.5 mg / dm², fluorine-free).

[0035] Innovative Sealed Drainage Structure: This invention features an innovative unactivated drainage structure that cleverly balances the sealing requirements of the first stage of use with the drainage requirements of the second stage by utilizing a pre-designed weakened zone and a non-water-soluble, non-dissolving sealing section. The sealing section remains intact during the hot beverage stage, while during the seedling stage, a drainage channel can be easily formed with a specific activation force (10-15N). Furthermore, the amount of debris shedding is extremely low, avoiding microplastic contamination and ensuring drainage, aeration, and environmental safety during the seedling process.

[0036] High-value utilization of waste resources: The seedling kit provided by this invention uses coffee grounds discarded from stores as a seedling substrate after stabilization treatment. This not only realizes the resource utilization of coffee grounds, but also provides a suitable growth medium for plant growth. Combined with a digital traceability system, it greatly enhances users' sense of participation and environmental awareness, and promotes the application of the circular economy model in the beverage industry. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the transformation seedling cup described in this invention.

[0038] In the diagram, 1-the internal space of the seedling cup; 2-biodegradable barrier coating; 3-paper-based cup body; 4-drainage channel; 5-preset weakened zone; 6-sealing part. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention. Unless otherwise stated, the raw materials used in this embodiment are commercially available industrial products or can be prepared by conventional methods. Unless otherwise specified, performance testing methods are performed according to the standards described in the invention summary section.

[0040] Figure 1This is a schematic diagram of the structure of the transformation seedling cup described in this invention, wherein the left view is a longitudinal sectional view of the transformation seedling cup, and the right view is an enlarged plan view of the drainage structure to be activated at the bottom of the cup. In the figure, reference numeral 1 represents the internal space of the transformation seedling cup, reference numeral 2 represents the biodegradable barrier coating, reference numeral 3 represents the paper-based cup body, reference numeral 4 represents the drainage channel, reference numeral 5 represents the preset weakened area, and reference numeral 6 represents the sealing part.

[0041] The following describes a specific implementation of the secondary seedling paper cup recycling and conversion system and the fluorine-free barrier coating, combining the processes of store-side recycling, pretreatment, activation and filling, kit distribution, interactive traceability, and end-of-life composting or soil return.

[0042] The diversion and recycling module, located in the store's recycling area, includes a limiting opening structure, an anti-misplacement structure, a flow guiding structure, and a visual prompt structure. The limiting opening structure is a circular inlet with an inner diameter of 82mm to match the 80mm inner diameter of a 250mL paper cup. The anti-misplacement structure is a cross-shaped limiting grid with a grid spacing of 35mm to prevent large containers such as plastic bottles from being mistakenly disposed of. The flow guiding structure is a 45° inclined flow channel to guide the paper cup into the recycling bin. The visual prompt structure includes a graphic sign and a QR code indicating "Seedling kit available after disposal."

[0043] The residual liquid control and pretreatment module includes a residual liquid quantity determination structure, a rinsing and spraying structure, a draining structure, a wiping structure, a disinfection structure, and a drying structure. The residual liquid quantity determination structure is a weighing platform equipped with an electronic balance (graduation value 0.001g); the weighing threshold is m0 + 0.30g, where m0 is the average mass (n=30) of the same batch of empty cups after equilibration for 24 hours at 23℃ and 50% relative humidity (RH). When the mass of any recycled paper cup is mt, its residual moisture is calculated as (mt - m0); a condition where (mt - m0) ≤ 0.30g / cup is considered dry. The rinsing spray structure uses a ring nozzle to spray 50mL of deionized water into the cup for 10 seconds; the draining structure uses an inverted drain rack for 30 seconds; the wiping structure uses a disposable non-woven cloth to wipe the inner surface of the cup once; the disinfection structure uses 254nm ultraviolet irradiation, with the ultraviolet lamp 100mm away from the cup rim, an irradiation intensity of 2.0mW / cm², and an irradiation time of 120 seconds; the drying structure uses 60℃ hot air drying at a wind speed of 3.0m / s for 180 seconds. After drying, the paper cup is left to cool at 23℃ and 50% RH for 60-120 seconds, and weighed within 60 seconds after cooling to obtain mt. After the above treatment, the inner surface of the paper cup reaches a dry state with "no visible water film and residual moisture ≤0.30g / cup".

[0044] The drainage activation and seedling filling module includes a limiting fixture and a positioning pressure head. The limiting fixture consists of a 56mm outer diameter positioning hole at the bottom of the cup and a cup-mouth limiting ring, with the positioning hole and cup-mouth limiting ring being coaxial. The positioning pressure head is a 10mm diameter flat-headed cylindrical pressure head with a stroke of 5mm and a pressing speed of 50mm / min. Under the constraint of the limiting fixture, the activation bursting force is controlled to be 12N. The pretreated paper cup is placed inside the limiting fixture, and the positioning pressure head is aligned with the center of the preset weakened area at the bottom of the cup and pressed to fold the sealing part and form no less than 3 drainage channels. Then, 200mL of the substrate component is filled into the cup and gently pressed to level it. The seed module is placed and the substrate is covered to a sowing depth of 5mm.

[0045] Kit Distribution Module: Provides individually packaged substrate components (net content 200mL), seed modules (20 seeds per pack), planting guide components, activation tool components (disposable press needles), and effluent management components (biodegradable base). The biodegradable base has an inner diameter of 90mm and a side height of 15mm, and is used to collect effluent for secondary irrigation.

[0046] User interaction and traceability module: A QR code is printed on the outer surface of the paper cup as an interaction identifier; after scanning the code, the system records the paper cup batch, store number, recycling time, pretreatment status (measured residual moisture value, disinfection method, drying method), kit type, and user operation records (activation time, number of watering check-ins, growth pictures), and outputs corresponding planting guidance information. When Near Field Communication (NFC) tags or Radio Frequency Identification (RFID) tags are required, the tags are set to a detachable structure: specifically, the NFC / RFID tag is pasted on a peelable outer paper label, which can be separated from the paper cup body; or the NFC / RFID tag is set on an outer kit that is separate from the paper cup body to prevent the tag from entering the composting / soil process with the paper cup.

[0047] Composting or Soil Regeneration Module: After seedling cultivation is completed, the user is prompted to carry out controlled composting (58℃ aerobic composting) or soil degradation treatment together with the seedling paper cups and substrate; when the paper cups use NFC tags or RFID tags, the user is prompted to remove the outer paper tag or the tag on the outer casing before composting or soil regeneration treatment.

[0048] The main reagents and raw materials are shown in Table 1.

[0049] Table 1. Main reagent and raw material names, product models and manufacturers:

[0050]

[0051] The main analytical and testing instruments are shown in Table 2.

[0052] Table 2 mainly analyzes the names, models, and manufacturers of the testing instruments:

[0053]

[0054] Table 3. Main test items, standard numbers, standard names, and key test conditions:

[0055]

[0056] Determination of total organic fluorine (TOF):

[0057] Take a paper cup sample (including coating, paper base, adhesive, and ink), cut it into pieces smaller than 2mm × 2mm, and accurately weigh 1.0g. Perform ultrasonic extraction three times with deionized water, adding 50mL of fresh deionized water each time in an ultrasonic cleaner (frequency 40kHz, power 200W, water bath temperature 25℃±2℃, 30min each time) to remove inorganic fluorine interference. Filter and dry to constant weight in a 60℃ forced-air drying oven to obtain the extraction residue. Place the dried residue in an oxygen bomb combustion apparatus and burn it completely in an oxygen atmosphere of 3.0MPa. The absorbent is 10mL of deionized water. After the combustion products were absorbed, the concentration of fluoride ions in the absorption liquid was determined by ion chromatography: the chromatographic column was an anion exchange column (such as IonPac AS19 or equivalent column), the eluent was KOH eluent (10 mmol / L isocratic), the flow rate was 1.0 mL / min, the column temperature was 30℃, the injection volume was 25 μL, and the suppressor was in electrochemical suppression mode; after establishing a calibration curve with fluoride ion standard solution, the total organic fluoride content in the sample (mg / kg) was converted, and the method detection limit was 5 mg / kg.

[0058] Determination of electrical conductivity and soluble solids content of coffee grounds:

[0059] Weigh 10.0 g of stabilized coffee grounds sample, add 100 mL of deionized water (solid-liquid ratio 1:10), mechanically stir at 25 °C for 30 min, let stand for 5 min, and then filter with quantitative filter paper to obtain water extract; measure and record the total volume V0 (mL) of the water extract obtained after filtration using a graduated cylinder.

[0060] (1) Conductivity: The conductivity (mS / cm) of the water extract was directly measured at 25℃ using a conductivity meter.

[0061] (2) Soluble solids: Accurately pipette V1 = 50.0 mL of the water extract into a pre-weighed evaporating dish, evaporate to dryness on a water bath, and then transfer to a 105℃ oven to dry to constant weight. Record the mass of the evaporation residue as m. R (g) (i.e., the final mass of the evaporating dish minus the constant weight of the evaporating dish). Calculation formula: Soluble solids (%) = m R ×V0 / (V1×m S )×100%, where mS is the mass of the coffee grounds sample, m S =10.0g.

[0062] Determination of water immersion mass loss rate of the sealing section:

[0063] Cut a complete sealing section (including coating or film) from the bottom of the prepared paper cup, or prepare a film of the same thickness and formula separately, and cut it into 20mm × 20mm samples. Equilibrate the samples at 23℃ and 50% RH for 24 hours, and weigh the initial mass m1. Immerse the samples in 200mL of pure water (25℃) for 24 hours, remove them, blot the surface moisture with filter paper, and dry them in a 60℃ forced-air drying oven until constant weight, then weigh the final mass m2. Calculation formula: Mass loss rate (%) = (m1 - m2) / m1 × 100%.

[0064] General preparation and construction process:

[0065] Preparation process of PVA aqueous solution (10wt%):

[0066] Step 1: Add PVA to deionized water or purified water at 10wt%, and stir with a mechanical stirrer at 300r / min for 10min to obtain PVA slurry.

[0067] Step 2: Place the PVA slurry from Step 1 in a constant temperature circulating bath at 90°C and stir for 30 minutes until the solution is clear and free of visible particles, thus obtaining a clear PVA solution.

[0068] Step 3: Cool the clarified PVA solution from Step 2 to 25°C and allow it to stand to remove bubbles, thus obtaining an aqueous PVA solution.

[0069] Preparation process of polybutylene succinate aqueous emulsion:

[0070] Step 1: Place the PVA aqueous solution in a constant temperature circulating bath at 92℃ and stir with a mechanical stirrer at 400r / min for 30min to obtain a heated PVA aqueous solution.

[0071] Step 2: Place the polybutylene succinate resin particles in a constant temperature circulating bath at 130°C and heat for 20 minutes to obtain polybutylene succinate melt.

[0072] Step 3: Slowly add the polybutylene succinate melt from Step 2 to the heated PVA aqueous solution from Step 1, and shear it for 8 minutes at 1500 r / min using a high-shear disperser to obtain a thermally emulsified emulsion.

[0073] Step 4: The hot emulsion from Step 3 is stirred with a mechanical stirrer at 400 rpm for 20 minutes and then cooled to 25°C to obtain a crude emulsion.

[0074] Step 5: Add deionized water or purified water to the crude emulsion from Step 4 to adjust the solid content to 50 wt%, and filter to obtain polybutylene succinate aqueous emulsion.

[0075] Stabilized coffee grounds preparation process:

[0076] Step 1: Take fresh coffee grounds (from freshly ground coffee, used within 24 hours after extraction) and add them to drinking water or deionized water at a ratio of coffee grounds wet weight: water volume = 1:10 (g:mL). Mix with a mechanical mixer at 300 rpm for 5 minutes, then pour out the water to drain. Let the water stand for 2 minutes through a 200-mesh sieve. Repeat the washing process 3 times to obtain washed coffee grounds.

[0077] Step 2: Spread the washed coffee grounds from Step 1 onto a tray with a thickness of ≤10mm, place them in a forced-air drying oven at 105℃ for 2 hours, and then cool them to room temperature to obtain heat-treated coffee grounds.

[0078] Step 3: Place the heat-treated coffee grounds from Step 2 into a forced-air drying oven at 70°C and dry them to a moisture content of 8%. Seal the oven to obtain stabilized coffee grounds.

[0079] Seedling substrate preparation process:

[0080] Step 1: Soak the coconut coir blocks in drinking water or purified water for 30 minutes, then drain off the free water and loosen them by hand until there are no obvious clumps, thus obtaining loosened coconut coir.

[0081] Step 2: Mix the loosened coconut coir and perlite in a volume ratio of 3:1. Stir for 5 minutes to obtain the basic seedling substrate.

[0082] Step 3: Add stabilized coffee grounds to the basic seedling substrate from Step 2 at a volume fraction of 10%, stir for 5 minutes to obtain the compound substrate.

[0083] Step 4: Disassemble and seal the compounded matrix from Step 3 to obtain individually packaged matrix components.

[0084] Construction process of 58℃ aerobic composting simulation device:

[0085] Step 1: Connect the sealed reaction chamber to the temperature-controlled heating and oxygen supply system, lay a ventilation layer inside the chamber and preheat it to 58°C; connect the gas outlet of the reaction chamber to a carbon dioxide capture system, which is a two-stage sodium hydroxide solution absorption bottle or an infrared CO2 analyzer, to obtain the preheated reaction system.

[0086] Step 2: After pretreating the mature compost inoculum at 58℃ for 24 hours, mix it with the sample at a dry weight ratio of "inoculum:sample = 6:1"; the sample is a shredded paper cup with a size of 20mm × 20mm; spray deionized water to adjust the moisture content of the mixture to 55% to obtain the mixture to be tested.

[0087] Step 3: Place the mixture to be tested in Step 2 at 58℃ and continuously supply oxygen with a blower at a flow rate of 50 mL / min; at the same time, set up a blank group to obtain aerobic compost samples.

[0088] Step 4: Carbon dioxide measurement: When using sodium hydroxide solution absorption bottles, replace the absorption liquid every 24 hours and calculate the CO2 absorption; when using an infrared CO2 analyzer, continuously record and integrate the CO2 concentration; subtract the blank group from the cumulative CO2 release of the sample group to obtain the net CO2 release.

[0089] Step 5: Disintegration rate determination: Take samples on day 45, sieve them using a 2mm standard sieve, and calculate the disintegration rate by "1 - (dry mass of residual sample on sieve / dry mass of initial sample added)".

[0090] Step 6: Biodegradation rate determination: On day 90, the ratio of the net CO2 release of the sample group to the theoretical maximum CO2 release of the sample is calculated to obtain the biodegradation rate.

[0091] Seed module preparation process:

[0092] Step 1: Cut the paper base paper into strips and number them to obtain biodegradable carrier strips.

[0093] Step 2: Arrange 20 Chinese cabbage seeds on the surface of the biodegradable carrier strip from Step 1, and apply a 10wt% PVA aqueous solution prepared by a general preparation process to form an adhesive layer, thus obtaining the adhesive carrier strip.

[0094] Step 3: Place the bonding carrier strip from Step 2 in a constant temperature incubator at 40℃ and dry for 30 minutes to obtain the seed module.

[0095] Water-based starch adhesive (for bonding cup seams, homemade) preparation process:

[0096] Step 1: Weigh 100g of corn starch and add 300g of deionized water. Stir mechanically at 300r / min for 10min to disperse the starch into a uniform starch slurry.

[0097] Step 2: Heat the uniform starch slurry from Step 1 to 90°C and keep it warm for 20 minutes to fully gelatinize the starch, thus obtaining gelatinized starch paste.

[0098] Step 3: Cool the gelatinized starch paste from Step 2 to 60°C, add 5g of sodium hydroxide solution (10wt%) to adjust the pH to 9.5, continue stirring for 10 minutes, and let it stand at 25°C for 30 minutes to remove bubbles, thus obtaining an aqueous starch gel.

[0099] Step 4: Apply the water-based starch adhesive from Step 3 to the seams of the paper cup body, control the wet coating amount to 30g / m², and dry it in hot air at 95℃ for 120s to obtain the seam adhesive layer.

[0100] Preparation process of 2.0wt% aqueous dispersion of nanocellulose (CNF):

[0101] Step 1: Add nanocellulose raw material (on a dry basis) to deionized water or purified water according to the target solid content of 2.0 wt% to obtain cellulose mixture.

[0102] Step 2: Disperse the cellulose mixture from Step 1 at 1500 rpm for 3 min using a high-shear disperser, and then stir at 300 rpm for 10 min using a mechanical stirrer to obtain a uniform CNF dispersion.

[0103] Step 3: Let the uniform CNF dispersion from Step 2 stand at 25°C for 30 min to degas; if necessary, filter through a 100 μm filter to remove undispersed agglomerates, and obtain a 2.0 wt% CNF aqueous dispersion.

[0104] Mature compost inoculum preparation process:

[0105] Mature aerobic compost conforming to GB / T 19277.1-2025 was selected as the inoculum for composting, preferably from municipal or garden waste aerobic composting facilities. After collection, the compost was spread out at 23℃ for 24 hours to release free gases and homogenize. Large particles were then removed by passing it through a 2mm standard sieve, and the moisture content was measured and adjusted to 55%–60% with deionized water. Before the composting experiment, the inoculum was pretreated at 58℃ for 24 hours to obtain mature compost inoculum.

[0106] Construction process of industrial composting testing equipment (including CO2 metering system):

[0107] Step 1: Select a 20L stainless steel sealed reaction box, wrap the outer layer with 50mm thick polyurethane insulation material, and lay a porous ceramic aeration plate at the bottom inside.

[0108] Step 2: Connect the proportional-integral-derivative (PID) temperature control heating system to the reaction chamber jacket and set the constant temperature to 58℃; connect the air compressor to the air inlet of the aeration plate via a rotor flow meter, control the flow rate at 50mL / min, and connect a humidifier bottle in series on the air inlet pipe to maintain the relative humidity of the incoming air greater than 90%.

[0109] Step 3: A condenser (for reflux of condensate) and two-stage absorption bottles are connected in series at the gas outlet of the reaction chamber; 100.0 mL of 0.50 mol / L sodium hydroxide solution is added to each of the first and second stage absorption bottles to capture the generated carbon dioxide. When using an online infrared CO2 analyzer for real-time monitoring, a non-dispersive infrared (NDIR) CO2 analyzer is preferred, and zero-point and span calibration is performed with zero gas and a standard gas of known concentration before the experiment; in this embodiment, two-stage sodium hydroxide absorption bottles are used for measurement, and the CO2 absorption is calculated according to the titration method in Application Example 3.

[0110] Step 4: After assembly, ventilate the system to check for air tightness and ensure there are no leaks, thus obtaining the industrial composting test device.

[0111] Laser drilling device setup process:

[0112] Step 1: Set up the optical path system. Select a nanosecond ultraviolet pulse laser with a wavelength of 355nm and a power of 5W as the light source. After the beam is collimated by the beam expander, it enters the high-speed galvanometer scanning system.

[0113] Step 2: Configure an F-theta flat-field focusing lens with a focal length of 160mm to focus the laser beam onto the processing plane; install a high-resolution charge-coupled device (CCD) industrial camera and vision positioning system directly above the processing plane to identify the circular outline and center coordinates of the bottom of the paper cup.

[0114] Step 3: Connect the industrial control computer to the laser control card, install the dedicated laser marking software, and set the micro-hole array pattern (hole diameter 100μm, hole spacing 400μm). Set the processing parameters as follows: pulse frequency 30kHz, scanning speed 1500mm / s, average laser output power (working surface) 3.0W, pulse width 15ns; the focal point is set 0.10mm below the upper surface of the paper substrate. Drill each hole using a fixed-point repetitive pulse method, with 60 repeated pulses per hole, and repeat the drilling process twice. After drilling, randomly inspect at least 30 holes using an optical microscope and calculate the hole diameter, controlling it within 100μm ± 10μm. If the hole diameter deviates, fine-tune the average laser output power in 0.2W increments and re-inspect until the hole diameter requirement is met.

[0115] Preparation process of positioning pressure head and limiting tooling:

[0116] Step 1: Use aluminum alloy (grade 6061) to machine the tooling base by CNC. The base is machined with a limiting ring (inner diameter 80mm) that matches the size of the rolled edge of the paper cup mouth and a positioning hole (inner diameter 56mm) that matches the size of the cup bottom, ensuring that the coaxiality deviation between the limiting ring and the positioning hole is less than 0.05mm.

[0117] Step 2: Use stainless steel (304 grade) to process a flat-headed cylindrical indenter with a diameter of 10mm. The bottom surface of the indenter is polished (surface roughness Ra≤0.4μm). The tail of the indenter is designed with a threaded interface to connect to an electronic tensile testing machine or a pneumatic actuator.

[0118] Step 3: Fix the tooling base to the test platform, adjust the axis of the pressure head to make it vertical and pass through the center of the positioning hole, and obtain the positioning pressure head and the limiting tooling.

[0119] Preparation method of coating composition:

[0120] Step 1: At 40°C, add PHA aqueous emulsion and optional polybutylene succinate aqueous emulsion to a container according to the ratio in Table 4, and stir with a mechanical stirrer at 300 r / min for 15 min to obtain a polymer mixture.

[0121] Step 2: Add PVA aqueous solution to the polymer mixture from Step 1 at 40℃ and continue stirring for 15 minutes to obtain a stable polymer mixture.

[0122] Step 3: Add the barrier reinforcement component after pre-dispersing it with water; wherein, when the barrier reinforcement component is modified flaky kaolin powder, prepare a 20wt% filler slurry according to the ratio of kaolin:deionized water = 1:4 (mass ratio) and disperse it with a high shear disperser for 5 minutes; when the barrier reinforcement component is nanocellulose, it is preferred to use the 2.0wt% aqueous dispersion prepared by the "Preparation Process of 2.0wt% Aqueous Dispersion of Nanocellulose (CNF)" as the filler slurry.

[0123] Step 4: Add the filler slurry from Step 3 to the stabilized polymer mixture from Step 2 at 40℃ and disperse under high shear for 5 minutes to obtain the filler dispersion.

[0124] Step 5: Add tributyl acetylacetate or polyethylene glycol to the filler dispersion from Step 4 at 40°C, stir for 10 min, and then shear and disperse for 3 min at 1500 r / min using a high-shear disperser to obtain a plasticized dispersion.

[0125] Step 6: Add alkyl polysaccharide wetting agent, defoamer and hydroxyethyl cellulose thickener to the plasticized dispersion in Step 5 at 40℃, stir for 10 min to obtain the base coating liquid.

[0126] Step 7: When the amount of the crosslinking curing component γ-(2,3-epoxypropoxy)propyltrimethoxysilane is greater than 0 parts by mass, the silane and deionized water are mixed at a mass ratio of silane:water = 1:9 and mechanically stirred for 5 min. After adjusting the pH to 4.5±0.1 with glacial acetic acid, the mixture is allowed to stand at 25℃±2℃ for 30 min to obtain the silane hydrolysate.

[0127] Step 8: At 30°C, add the silane hydrolysate from Step 7 dropwise to the base coating solution from Step 6. Monitor the pH with a pH meter and adjust the final pH to 7.8 with a 10wt% sodium hydroxide aqueous solution. Filter through 100μm to obtain the coating solution. When the amount of silane used is 0 parts by mass, skip Step 7 and directly adjust the final pH of the base coating solution from Step 6 to 7.8 with a 10wt% sodium hydroxide aqueous solution. Filter through 100μm to obtain the coating solution. Water is added as a solvent or dispersion medium to adjust to a suitable coating viscosity. The total solid content of the coating solution is adjusted to 40wt%. The viscosity (mPa·s) of the coating solution is measured using a Brookfield rotational viscometer at 25°C, with a rotor LV-3 and a rotation speed of 60 r / min. The target viscosity of the coating solution is controlled between 500 mPa·s and 1500 mPa·s. This viscosity is recorded as a reproducibility control index.

[0128] Method for preparing convertible seedling cups:

[0129] Step 1: Cut the paper base into cup body pieces and cup bottom pieces; form a laser micro-hole array area in the center of the cup bottom piece, the micro-hole array area is a circular area with a diameter of 12.0 mm, the micro-hole diameter is 100 μm and the hole spacing is 400 μm; use a paper cup forming machine to form a concentric annular weakening area on the cup bottom piece with an indentation die, the diameter of the center circle of the weakening line of the weakening area is 20.0 mm, the width of the weakening line is 0.6 mm, and 5 discontinuous connection points are evenly arranged along the circumference of the concentric annular weakening area, with each connection point having a width of 1.0 mm; punch a pull ring type activation component on the outside of the cup bottom piece, the outer diameter of the pull ring is 15 mm, to obtain the pre-treated paper piece.

[0130] Step 2: Coat the pretreated paper sheet from Step 1 with the coating solution, controlling the dry film thickness of the barrier film layer inside the cup to 20 μm, to obtain a wet-coated paper sheet; the dry film thickness is determined using the differential thickness method: before coating, use a paper thickness gauge or digital micrometer (1 μm resolution, 100 kPa measurement pressure, 1 s holding time) to randomly measure 10 points in the coating area of ​​the pretreated paper sheet to obtain the average substrate thickness h0; after coating and drying according to Step 3, randomly measure 10 points in the same area to obtain the average thickness h1 after coating; the dry film thickness t = h1 - h0. Adjust the wet coating amount (or doctor blade gap) of the laboratory coating machine to make t 20 μm.

[0131] Step 3: Dry the wet coated paper sheet from Step 2 in hot air at 100℃ for 120 seconds to obtain the dry coated paper sheet.

[0132] Step 4: Form a sealing portion in the weakened area of ​​the cup bottom of the dried coated paper sheet in Step 3; Method A (Sealing Coating): Coating liquid is applied again to the weakened area and dried in hot air at 100℃ for 120s to form a sealing coating. The dry film thickness of the sealing coating is measured and controlled to be 15μm using the differential thickness method described above; Method B (Sealing Film): A wet film is prepared on silicone paper using a film scraper. When the total solid content of the coating liquid is 40wt%, the scraper blade gap is set to 40μm. Then, it is dried in a 60℃ forced-air drying oven to constant weight and peeled off to obtain a dry film. The dry film thickness is verified to be 15μm using the differential thickness method; The dry film is covered on the preset weakened area at the bottom of the cup and bonded under hot pressing conditions (hot pressing temperature 110℃, pressure 0.20MPa, holding time 10s) to obtain a paper sheet with a sealing portion.

[0133] Step 5: The cup body and cup bottom sheets obtained in Step 4 are formed into paper cups on a paper cup forming machine (DB-12): After the cup body sheet is rolled into a tube, water-based starch adhesive is applied to the side seams at a wet coating amount of 30g / m², and then dried in 95℃ hot air for 120s to form an adhesive layer for the cup body seams; then the cup bottom sheet is assembled and rolled and sealed, with the rolling and sealing heating head temperature set at 180℃, the rolling and sealing pressure at 0.25MPa, and the rolling and sealing time at 0.8s; the formed paper cups are equilibrated in an environment of 23℃ and 50% RH for 24 hours to obtain convertible seedling cups.

[0134] Example:

[0135] Example 1: This example provides a biodegradable barrier coating composition for convertible seedling cups. Based on solid components, the composition comprises: 30 parts by weight of a PHA film-forming component (based on solids), specifically a PHBV aqueous emulsion with a solid content of 48 wt%; average particle size (D... 50 The coating consists of: 1.3 μm; 4.9 parts by weight of PVA dispersion stabilizing component, specifically an aqueous solution of PVA 1788 prepared using a general preparation process, with a solid content of 10 wt%; 40 parts by weight of barrier reinforcing component, specifically modified flaky kaolin (Barrisurf HX); 20 parts by weight of plasticizing component, specifically tributyl acetylacetic acid (ATBC); 5.0 parts by weight of crosslinking curing component, specifically γ-(2,3-epoxypropoxy)propyltrimethoxysilane (KH-560); and 0 parts by weight of wetting, defoaming, and rheology modifier. The above components were blended at 40°C according to the "Preparation Method for Coating Compositions" to obtain a coating solution with a pH of 7.8.

[0136] Example 2: This example provides a biodegradable barrier coating composition for convertible seedling cups. Based on solid components, the composition comprises: 45 parts by weight of a PHA film-forming component (based on solids), specifically a PHBV aqueous emulsion (parameters same as in Example 1); 3.5 parts by weight of a PVA dispersion stabilizing component (PVA 1788); 30 parts by weight of a barrier reinforcing component, specifically modified flaky kaolin; 15 parts by weight of a plasticizing component, specifically polyethylene glycol (PEG-400); 4.0 parts by weight of a crosslinking curing component (KH-560); and 2.5 parts by weight of a wetting, defoaming, and rheology modifier, wherein the alkyl polysaccharide glycoside (APG) wetting agent is 0.8 parts by weight, the fluorine-free defoamer is 0.2 parts by weight, and the hydroxyethyl cellulose (HEC) thickener is 1.5 parts by weight. The preparation process is the same as in Example 1.

[0137] Example 3: This example provides a compound biodegradable barrier coating composition. Based on solid components, it includes: 42 parts by weight of PHBV aqueous emulsion (parameters same as in Example 1); 18 parts by weight of polybutylene succinate (PBS) aqueous emulsion, specifically BioPBS FZ91PMPTT emulsion prepared using a general preparation process, with a solid content of 50 wt% and an average particle size of 1.0 μm; 2.5 parts by weight of PVA 1788; 20 parts by weight of nanocellulose (CNF), specifically Exilva F 01-V aqueous dispersion prepared using a general preparation process; 10 parts by weight of ATBC; 3.0 parts by weight of KH-560; and 4.5 parts by weight of functional additives, including 1.2 parts by weight of alkyl polysaccharide glycoside (APG) wetting agent, 0.3 parts by weight of fluorine-free defoamer, and 3.0 parts by weight of hydroxyethyl cellulose (HEC) thickener. The preparation process is the same as in Example 1.

[0138] Example 4: This example provides a biodegradable barrier coating composition. Based on solid components, it comprises: 80 parts by weight of PHBV aqueous emulsion (parameters same as in Example 1); 1.0 part by weight of PVA 1788; 10 parts by weight of nanocellulose (CNF); 5.0 parts by weight of PEG-400; 2.0 parts by weight of KH-560; and 2.0 parts by weight of functional additives, wherein the alkyl polysaccharide glycoside (APG) wetting agent is 0.6 parts by weight, the fluorine-free defoamer is 0.2 parts by weight, and the hydroxyethyl cellulose (HEC) thickener is 1.2 parts by weight. The preparation process is the same as in Example 1.

[0139] Example 5: This example provides a biodegradable barrier coating composition. Based on solid components, it comprises: 95.2 parts by weight of P34HB aqueous emulsion (based on solids), the emulsion having a solid content of 45 wt% and an average particle size of 1.4 μm; 0.1 parts by weight of PVA 1788; 0 parts by weight of barrier reinforcing component; 0 parts by weight of plasticizing component; 0 parts by weight of crosslinking curing component; and 4.9 parts by weight of functional additives, including 1.2 parts by weight of alkyl polysaccharide glycoside (APG) wetting agent, 0.3 parts by weight of fluorine-free defoamer, and 3.4 parts by weight of hydroxyethyl cellulose (HEC) thickener. The preparation process is the same as in Example 1.

[0140] Example 6: This example provides a biodegradable barrier coating composition. Based on solid components, it comprises: 50 parts by weight of PHBH aqueous emulsion (based on solids), the emulsion having a solid content of 45 wt% and an average particle size of 1.2 μm; 4.0 parts by weight of PVA1788; 20 parts by weight of modified flaky kaolin; 10 parts by weight of ATBC; 3.0 parts by weight of KH-560; and 3.0 parts by weight of functional additives, wherein the alkyl polysaccharide glycoside (APG) wetting agent is 0.8 parts by weight, the fluorine-free defoamer is 0.2 parts by weight, and the hydroxyethyl cellulose (HEC) thickener is 2.0 parts by weight. The preparation process is the same as in Example 1.

[0141] Table 4 Formulation of Barrier Coating Compositions in Examples 1-6 (Unit: Parts by weight of solids):

[0142]

[0143] Note:

[0144] Barrier reinforcement components: Modified flaky kaolin was used in Examples 1, 2 and 6; nanocellulose (CNF) was used in Examples 3 and 4.

[0145] Plasticizing components: acetylated tributyl citrate (ATBC) was used in Examples 1, 3, and 6; polyethylene glycol (PEG-400) was used in Examples 2 and 4.

[0146] Crosslinking and curing components: all are γ-(2,3-epoxypropoxy)propyltrimethoxysilane.

[0147] Functional additives: including alkyl polysaccharide glycoside (APG) wetting agents, defoamers and hydroxyethyl cellulose (HEC) thickeners.

[0148] Comparative Example

[0149] Comparative Example 1: A conventional polyethylene (PE) coated paper cup is provided as a control. This paper cup uses 280g / m² paper base paper, with a 15μm thick low-density polyethylene (LDPE) coated layer on the inner surface. The material is non-biodegradable.

[0150] Comparative Example 2: A polylactic acid (PLA) coated paper cup was provided as a control for biodegradable materials. The paper cup was made of 280 g / m² paper base paper, with a 20 μm thick Ingeo 4032D PLA coating layer laminated on the inner surface.

[0151] Comparative Example 3: A pure PHB coated paper cup is provided. The coating formulation is: 100 parts by weight of PHB aqueous emulsion (the solid content of the emulsion is 48% on a solid basis), which does not contain PVA, barrier reinforcing components, plasticizing components and crosslinking curing components.

[0152] Comparative Example 4: Based on the coating formulation and paper cup structure of Example 2, the only difference is that the sealing part at the bottom of the cup is not a biodegradable sealing coating formed by a second coating and drying of the coating liquid that forms the biodegradable barrier coating inside the cup at a preset weakened area, but a water-soluble PVA film is used as the sealing part; the mass loss rate of this sealing part after soaking in pure water at 25°C for 24 hours is 32.0%, and it loses its seal prematurely during the process of holding hot water at 95°C for 4 hours, resulting in leakage of the cup body. The leakage amount in 4 hours is 520mg, which cannot meet the heat-resistant liquid sealing requirements of the first stage of use.

[0153] Comparative Example 5: Based on the coating composition of Example 2, the ratio was adjusted to: 45 parts by mass of PHBV, 9.0 parts by mass of PVA, and the remaining components were the same as in Example 2. This was used to verify the effect of the PHA / PVA ratio.

[0154] Comparative Example 6: Based on the paper cup of Example 2, the only difference is that the simulation did not use the "no visible water film on the inner surface of the paper cup and residual moisture ≤0.30g / cup" as the filling criterion and the forced drying scheme was not implemented accordingly. Instead, only rinsing, draining, and UV disinfection steps were performed (under the same conditions as described in the embodiment). The paper cup was then placed in a 23°C, 50% RH environment and allowed to air dry naturally for 600 seconds without external airflow, and the process was completed by visual inspection. (m) t The residual moisture content was calculated using the formula -m0), resulting in a paper cup residual moisture content of 0.45 g / cup, which exceeds the dryness limit of 0.30 g / cup. This leads to an increased hygiene risk during subsequent filling and makes it difficult to achieve the expected microbial control effect.

[0155] Comparative Example 7: The paper cup structure based on Example 2, the only difference being that the discontinuous connection points of the concentric annular weakening zone at the bottom of the cup are designed to be two, in order to verify the rationality of the weakening zone structure.

[0156] Comparative Example 8: The paper cup structure based on Example 2, the only difference being that the number of discontinuous connection points in the concentric annular weakening zone at the bottom of the cup is designed to be 9, in order to verify the rationality of the weakening zone structure.

[0157] Comparative Example 9: Based on the seedling kit of Example 2, the only difference is that: simulating the scheme where the volume fraction of stabilized coffee grounds in the substrate component was not controlled within the range of 3% to 20%, the volume fraction of stabilized coffee grounds was adjusted to 25% to verify the adverse effects of exceeding the volume fraction range on germination rate and plant height.

[0158] Comparative Example 10: Based on the coating preparation process of Example 2, the only difference is that the simulation blending temperature was not limited to ≤50°C, and the blending temperature in the coating composition preparation process was set to 65°C to verify the effect of exceeding 50°C on the dispersion system causing demulsification, layering / gelation and deterioration of barrier properties.

[0159] Comparative Example 11: Based on the coating formulation of Example 2, except that the amount of biodegradable membrane polymer (PHBV) was adjusted to 25 parts by weight.

[0160] Comparative Example 12: The coating formulation based on Example 2, except that the amount of the barrier reinforcing component (modified kaolin) was adjusted to 45 parts by mass.

[0161] Comparative Example 13: The coating formulation based on Example 2, except that the amount of plasticizer (PEG-400) was adjusted to 25 parts by weight.

[0162] Comparative Example 14: Based on the coating formulation of Example 2, except that the amount of crosslinking curing component (KH-560) was adjusted to 12 parts by weight.

[0163] Comparative Example 15: The coating formulation based on Example 2, except that the amount of PVA was adjusted to 0.05 parts by weight.

[0164] Table 5 provides an overview of the structural and key differences in Comparative Examples 4-15:

[0165]

[0166] Note:

[0167] Reference material: Unless otherwise specified, the PHA used in this table is PHBV, the barrier reinforcing component is modified flaky kaolin, the plasticizing component is PEG-400, and the crosslinking curing component is silane.

[0168] Comparative Examples 1-2: These are paper cups produced using traditional coating processes, without involving water-based barrier coating formulations.

[0169] Comparative Example 3: The film was formed by pure PHB aqueous emulsion, without other compound components, and was calculated in parts of 100.

[0170] Application example:

[0171] Application Example 1: Barrier performance test during the first stage of use.

[0172] Experiment Description: This experiment aims to simulate the actual working conditions of paper cups when they are used to hold hot beverages in the first stage of use, and to comprehensively evaluate their liquid-sealing performance and heat barrier stability. The paper cup samples to be tested were first subjected to a 24-hour constant temperature and humidity equilibration treatment at 23℃ and 50% RH.

[0173] Cobb absorbency: The weighing and calculation methods were performed according to GB / T 1540-2002, but the test water temperature was set to 95℃±1℃ and the absorption time was set to 30min. Specifically: the sample was cut from the paper cup body and flattened along the cup body, cut into 100mm×100mm (area 100cm²) pieces, avoiding the cup body seam area; the sample was held in place by the 100cm² pressure ring of the Cobb absorbency tester, ensuring the coated side faced the water side; after the water absorption was completed, the test water was poured out, and the surface free water was quickly absorbed with standard absorbent paper according to GB / T 1540-2002, and weighed immediately, with the electronic balance scale division value being 0.001g; the Cobb value (g / m²) was calculated based on the mass increment per unit area.

[0174] Leakage resistance: Pour 200mL of hot water with an initial temperature of 95℃±1℃ into the paper cup and let it stand for 4 hours at 23℃ and 50% RH without adding hot water. After wiping the outer wall of the paper cup dry, place the bottom of the cup on quantitative filter paper (200mm×200mm, basis weight 80g / m²) that has been pre-equilibrated at 23℃ and 50% RH for 24 hours and kept at constant weight. The mass of the filter paper is measured using an analytical balance with a scale division of 0.1mg. After standing, weigh the filter paper again to measure the mass increment. This mass increment is the leakage amount (mg), and record the softening and deformation of the cup body at the same time.

[0175] Coating adhesion: Refer to GB / T 9286-2021, use a cross-cutting tool with a 1mm spacing to make a 6×6 grid on the coating surface, then apply standard tape (such as 3M 600 or equivalent tape) and peel it off quickly in a 180° direction within 60 seconds after application. The coating is rated from 0 to 5 according to GB / T 9286-2021.

[0176] Each experiment was performed in parallel 5 times, and the average value was taken as the final result.

[0177] Table 6 Barrier performance test results:

[0178]

[0179] Note: "-" indicates that this comparative example is not applicable to this test. Comparative example 6 represents the difference in pretreatment process, and comparative example 9 represents the difference in seedling substrate. Their empty cup barrier performance is consistent with the example before the specific variable treatment or is not included as a variable in this experiment.

[0180] Analysis: Experimental data show that the component ratio of the coating formulation and the film-forming process have a significant impact on barrier performance. Examples 1-6, after immersion in 95℃ hot water for 30 min, maintained Cobb values ​​between 9.8 g / m² and 13.0 g / m², with 0 mg leakage over 4 h, and an adhesion rating of 0, confirming the film density and stability of the PHA / PVA composite system in a high-temperature liquid phase environment. In contrast, Comparative Examples 2 (PLA) and 3 (pure PHB), due to the inherent brittleness of the materials or lack of toughening modification, experienced adhesion degradation to grades 2-3 and significant leakage (120-250 mg). Comparative Example 4, due to the use of a water-soluble material in the sealing portion, completely failed during the test, with a leakage as high as 520 mg. Furthermore, data from Comparative Example 5 (PHA / PVA ratio imbalance), Comparative Example 10 (overly high blending temperature), and Comparative Example 15 (underly low PVA content) show that deviations from specific process parameters or formulation ranges can lead to film defects, significantly increasing the Cobb value and inducing leakage. Data from Comparative Example 8 further suggests that excessive structural connection points can cause stress concentration leading to minor leakage. In summary, this experiment verifies the effectiveness of specific formulation systems in ensuring the sealing performance of heat-resistant liquids.

[0181] Application Example 2: Drainage activation mechanical performance test during the second stage of use.

[0182] Experiment Description: This experiment focuses on evaluating the ease of operation and structural reliability of paper cups when they are transformed from beverage containers into seedling containers. A high-precision electronic tensile testing machine equipped with a 10mm diameter flat-head cylindrical probe was used. Before testing, the paper cup was fixed in a dedicated limiting fixture, ensuring that the probe axis was vertically aligned with the center point of the pre-set weakened area on the bottom of the cup. The probe's downward speed was set to 50mm / min, and the maximum force at the moment the probe pierced the weakened area and caused the seal to fold was recorded; this was the activation breaking force (N).

[0183] After activation, the number of effective drainage channels is counted using the "water injection observation method": 50mL of deionized water is added to the activated empty cup and the cup is kept vertical. The number of independent water outlets with continuous dripping on the outside of the bottom of the cup is recorded. The number of these outlets is the number of effective drainage channels. Continuous dripping is defined as at least 5 drops falling from the same outlet within 10 seconds. Independent water outlets are defined as water outlets with a distance greater than 2mm between them and clearly distinguishable on the outside of the bottom of the cup.

[0184] In addition, to assess the risk of fragment detachment, a drop hammer impact method was used: the activated empty cup was inverted and fixed so that the bottom of the cup was 50 mm above the surface of the collecting paper below; the collecting paper was a pre-weighed paper base (basis weight 280 g / m² and dimensions 200 mm × 200 mm). A 200 g rubber hammer (Shore A 60 hardness) was dropped freely within a vertical guide sleeve, released 100 mm above the outer surface of the cup bottom, impacting the center of the pre-set weakened area on the cup bottom, repeated 10 times; the detached fragments were collected and the mass increment of the collecting paper was measured using a 0.1 mg scale analytical balance, and the mass increment was the mass of the detached fragment (mg).

[0185] Five paper cups were measured in parallel for each group of samples (n=5). The activation bursting force, number of drainage channels and mass of fragments listed in Table 7 were all averaged from the five measurements.

[0186] Table 7. Test results of mechanical properties activated by drainage:

[0187]

[0188] Note: "-" indicates that this comparative example is not applicable to this test or cannot be completed. Comparative example 4 has a dissolved seal, so dry fragments cannot be measured; Comparative examples 6 and 9 do not involve changes in structure or material mechanical properties.

[0189] Analysis: Mechanical testing results show that the activation fracture forces of Examples 1-6 are all distributed between 10.2N and 14.5N, within the preset suitable operating range of 10N to 15N, and the fragment loss mass is extremely low (≤0.6mg), indicating that the material has good toughness and controlled fracture characteristics. Comparative Example 1 (PE coating) exhibits excessively high toughness, and under a force greater than 60N, it only undergoes overall deformation and cannot form channels. Conversely, Comparative Example 2 (PLA) shows significant brittleness; although the activation force is low (8.5N), it is accompanied by fragment loss of up to 65.0mg, posing an environmental risk. The influence of structural parameters is reflected in Comparative Examples 7 and 8: too few connection points (Comparative Example 7) lead to an increased activation force of 16.5N and incomplete channel opening; too many connection points (Comparative Example 8) reduce the activation force to 7.8N, resulting in insufficient structural stability. Experimental data confirms that the structural design of the pre-defined weakened zone and the toughening modification of the coating material are key to achieving a balance between low force activation and low fragment shedding.

[0190] Application Example 3: Composting Degradation Performance Test.

[0191] Experimental Description: This experiment, conducted according to GB / T 19277.1-2025 standard, evaluated the biodegradability of paper cups under controlled aerobic composting conditions at 58℃. Paper cup samples (including coating, ink, and adhesive) were cut into 20mm × 20mm fragments and mixed with mature compost inoculum at a dry weight ratio of 1:6. Deionized water was sprayed to adjust the moisture content to 55%, and the mixture was placed in an oxygen-supplied composting reactor at an oxygen flow rate of 50 mL / min. The experiment lasted 90 days, during which the compost was turned every 3 days to maintain aerobic conditions and water was added simultaneously to adjust the moisture content back to 55%. Three parallel composting reactors (n=3) were set up for each sample group, and three blank control reactors (n=3) were simultaneously set up to subtract background carbon dioxide release. The 45-day disintegration rate and 90-day biodegradation rate listed in Table 8 are the average values ​​of the parallel samples.

[0192] CO2 was collected using a two-stage sodium hydroxide solution absorption bottle: 100.0 mL of 0.50 mol / L sodium hydroxide solution was added to both the first and second stage absorption bottles; the absorption solutions were replaced every 24 hours. After thorough mixing of the replaced first-stage absorption solution, 10.0 mL was taken as the titration sample. The titration endpoint was monitored using a pH meter at 25℃ with 0.50 mol / L hydrochloric acid standard solution: first titrated to pH=8.3, recording the volume of hydrochloric acid consumed V1 (mL); then titrated further to pH=4.5, recording the total volume consumed V2 (mL); the amount of CO2 absorbed by this 10.0 mL sample solution, nCO2 = C... HCl ×(V2-V1) / 1000. Convert nCO2 according to the total amount of absorbent liquid to obtain the mass of CO2 absorbed in 24h, mCO2=nCO2×44.0g / mol, and sum them to obtain the cumulative CO2 release; subtract the blank group from the cumulative CO2 release of the sample group to obtain the net CO2 release.

[0193] Table 8. Test results of composting degradation performance:

[0194]

[0195] Note: "-" indicates that this comparative example is not applicable. Comparative Example 9 shows a difference in matrix formulation, but the paper cup body is the same as in Example 2, and the degradation performance is consistent.

[0196] Analysis: Composting experiment data shows that the coating system described in this invention has excellent industrial compostability. Examples 1-6 all exhibited a disintegration rate exceeding 92% at 45 days and a biodegradation rate exceeding 88.5% at 90 days, meeting relevant compostability standards. Example 5 (P34HB) showed the highest degradation efficiency (94.5% decomposition rate at 90 days). As a control, Comparative Example 1 (PE coating) showed virtually no degradation (<1%) during the experimental period. Notably, Comparative Example 2 (PLA) exhibited a significantly slower degradation rate than the PHA system under these experimental conditions, with a disintegration rate of only 65.2% at 45 days. The remaining Comparative Examples 3-8 and 10-15, whose main substrate components are biodegradable materials, all showed good degradation performance. The results confirm that while optimizing barrier and mechanical properties, the formulation of this invention does not sacrifice the biodegradability of the material, enabling effective degradation through composting or soil burial.

[0197] Application Example 4: Oil resistance, wetting and food contact safety tests during the first stage of use.

[0198] Experiment Description: This experiment aims to evaluate the oil penetration resistance, surface wettability, and food contact safety of the inner surface of paper cups to ensure their compliance as food containers.

[0199] Oil penetration resistance: The penetration test was conducted according to the "Penetration Judgment" standard of GB / T 22805.1-2008, but the oil dripping method based on the actual structure of the cup was used as an equivalent evaluation. The paper cup was placed in a constant temperature environment of 60℃, and 0.20mL of edible corn oil was dripped into the center of the inner side of the bottom of the cup. The penetration judgment point was defined as the appearance of a 5mm×5mm oil stain on the corresponding position on the outer wall of the cup that lasted for more than 30s. The test was conducted every 1min from the start of dripping and the time (min) from the start of dripping to the penetration judgment point was recorded.

[0200] Surface wettability: The static contact angle of deionized water on the coating surface was measured using a contact angle meter. The coated surface of the paper cup was cut and flattened into 30mm×30mm samples, and 5μL of deionized water was added. The contact angle was read 5 seconds after addition. Each sample was measured 5 times at different positions, and the average value was taken as the contact angle (°).

[0201] Food contact safety: Total migration was determined according to GB 31604.8-2021. Coated samples were cut into 1 dm² pieces and placed in a covered glass container. 100 mL of a 10 wt% ethanol aqueous solution was added (area / volume ratio of 1 dm² / 100 mL), and the mixture was kept at 70℃±1℃ for 2 h. After the treatment, the simulant was taken and evaporated according to GB 31604.8-2021, then dried at 105℃ to constant weight. The total migration was calculated (mg / dm²). Fluorescent substance detection was performed according to GB 31604.47-2023. The number of fluorescent spots within a 100 cm² area was observed under a 254 nm / 365 nm UV lamp.

[0202] Table 9. Results of oil resistance, wetting resistance, and food contact safety tests:

[0203]

[0204] Note: "-" indicates that this test is not applicable to this comparative example. Comparative examples 6 and 9 do not change the coating chemical formulation.

[0205] Analysis: Test results show that the total migration in Examples 1-6 was strictly controlled between 4.0 mg / dm² and 5.5 mg / dm², and the oil penetration resistance time was greater than 180 min, meeting the safety and functional requirements of food contact materials. Example 4 achieved the largest water contact angle (101°) and the lowest total migration (4.0 mg / dm²) through the synergistic effect of nanocellulose and PHBV. The data revealed the significant impact of formulation components on safety: Comparative Example 13, due to excessive PEG plasticizer content (25 parts), resulted in a surge in total migration to 13.0 mg / dm²; Comparative Example 15, due to insufficient PVA content leading to an unstable emulsion system and poor film density, also saw a total migration of 11.0 mg / dm². Furthermore, Comparative Examples 2 and 3 showed that single biodegradable materials have shortcomings in oil resistance and migration indicators. No fluorescent substances were detected in any samples. The experiment confirms that strictly controlling the proportions of plasticizers, emulsifiers, and matrix resins in the formulation is key to ensuring low migration.

[0206] Application Example 5: Dryness and microbial control test after pretreatment at the store.

[0207] Experiment Description: This experiment aims to verify the hygiene and dryness of recycled paper cups after undergoing a standard pretreatment process at the store. The pretreatment process includes: rinsing with 50mL of deionized water for 10s, draining by inversion for 30s, irradiation with 254nm ultraviolet light for 120s, and finally hot air drying at 60℃. The time (s) required from the start of drying until there is no visible water film on the inner surface of the cup and the residual moisture reaches ≤0.30g / cup is recorded; the residual moisture is calculated as (mt-m0). To facilitate rapid on-site judgment, filter paper imprints are used as an auxiliary criterion: a 20mm×20mm quantitative filter paper is cut and placed at any position on the inner surface of the cup. A standard weight of 200g (approximately 1.96N) is applied to the filter paper for 3s using a 20mm diameter flat-bottomed pressure block, and then removed. No continuous wet marks longer than 5mm appear on the filter paper.

[0208] After treatment, the paper cups were allowed to cool statically at 23℃ and 50% RH for 60-120 seconds, and weighed within 60 seconds after cooling to obtain mt. The residual moisture (g / cup) was calculated as (mt-m0), where m0 is the average mass of the same batch of empty cups after equilibration at 23℃ and 50% RH for 24 hours (n=30). The total bacterial count was determined according to GB 4789.2-2022: a disposable sterile cotton swab was dipped in sterile physiological saline and wiped once on the inner surface of the paper cup (covering the bottom and the entire contact area of ​​the inner side of the cup). The swab was then placed in a test tube containing 10.0 mL of sterile physiological saline and eluted by shaking for 60 seconds. After a 10-fold serial dilution, 1.0 mL was spread onto a PCA plate and incubated at 36℃±1℃ for 48h±2h. The total bacterial count (CFU / cup) was then calculated. Three paper cups were tested in parallel for each sample group (n=3), and the data in Table 10 were averaged.

[0209] Table 10 Results of Pretreatment Dryness and Microbial Control Tests:

[0210]

[0211] Note: "-" indicates that the comparative example is not applicable or cannot be tested. Comparative example 4 was damaged during the rinsing stage due to water solubility in the sealing part; Comparative example 9 does not involve the paper cup structure.

[0212] Analysis: Pretreatment experimental data showed that after standard processing, the residual moisture content of Examples 1-6 was below the set threshold of 0.30 g / cup, and the total bacterial count was controlled below 100 CFU / cup, meeting the hygiene standards for seedling filling. Example 4, due to its strongest surface hydrophobicity, had the highest drying efficiency (150 s, residual moisture 0.18 g). As a key control, Comparative Example 6, using natural air drying, resulted in a residual moisture content as high as 0.45 g / cup, accompanied by a significant increase in the total bacterial count to 320 CFU / cup, indicating a positive correlation between residual moisture and microbial growth. Comparative Example 5, due to its highly hydrophilic coating, had a slightly longer drying time. Although Comparative Examples 1 and 2 dried rapidly, their materials were either non-degradable or had unbalanced properties. The experimental results verified the necessity and effectiveness of the "residual moisture ≤ 0.30 g / cup" dryness criterion in controlling microbial risk.

[0213] Application Example 6: The impact of drainage efficiency and coffee grounds content on plant growth during the second stage of use.

[0214] Experiment Description: This experiment comprehensively evaluates the functional performance of the transformation seedling cups in the actual seedling process, and focuses on verifying the suitable range of stabilized coffee grounds content in the seedling substrate. Chinese cabbage was used as an indicator plant. After activating the drainage structure of each group of paper cups, substrate components containing different proportions of stabilized coffee grounds were filled, and seed modules were sown. The cups were then maintained in an artificial climate chamber (25℃, 16h / d light) for 14 days. Ten parallel seedling cups (n=10) were set up for each sample group. The average value of each indicator listed in Table 11 was taken from the ten parallel samples. Each group of seedling cups was placed in the biodegradable base of the seepage management component. During the maintenance period, 20mL of deionized water was poured onto the surface of the substrate in each cup at a fixed time (09:00) daily. After watering, the seepage in the base was collected, and 24 hours later, the seepage was re-irrigated onto the surface of the corresponding seedling cup substrate as secondary irrigation water.

[0215] Drainage time: On the first day, 100 mL of deionized water was uniformly injected into the surface of each substrate cup at one time. The time from the end of the water injection to the cessation of the last drop of water dripping from the bottom of the cup was recorded as the drainage time (s).

[0216] Wet lateral crushing force: After soaking the seedling cup in deionized water for 30 minutes, remove it and place it in a sealed environment until it becomes saturated with water, then keep it there for 24 hours. Next, place the empty cup between two parallel pressure plates of an electronic tensile testing machine, with the cup axis horizontal. The pressure plates are applied at a speed of 10 mm / min until the cup collapses noticeably and a peak load is observed. This peak load is recorded as the wet lateral crushing force (N). The test calculations refer to the load recording and peak value determination method in GB / T 4857.4-2008.

[0217] Germination rate: Based on the number of seeds sown per cup, count the number of seedlings whose cotyledons unfold and emerge from the substrate surface on the 7th day, and calculate the germination rate as "germination rate = number of germinated plants / number of seeds sown × 100%".

[0218] Plant height: On the 14th day, use a ruler to measure the height from the substrate surface to the highest point of the plant, and take the average value of all plants in each cup as the average plant height (cm).

[0219] Table 11 Plant growth test results:

[0220]

[0221] Analysis: Plant growth test results indicate that the structure of the seedling cup and the substrate formulation directly affect plant growth indicators. Examples 1-6 showed suitable drainage speed (30-45s) and good wet strength (40-58N), with germination rates all above 95%. Gradient experiments with coffee grounds content showed normal plant growth within the range of 3% to 20% addition, but when the content increased to 25% (Comparative Example 9), the germination rate significantly decreased to 82%, and plant height was inhibited (6.8cm), confirming the phytotoxicity of high concentrations of coffee grounds. The impact of structural defects on growth was evident in the comparative examples: Comparative Example 1 (PE) had a low germination rate (80%) due to impermeability; Comparative Example 7 (few holes) resulted in water accumulation; and Comparative Example 4 struggled to maintain its shape due to excessively low wet strength (15N). Experimental data confirmed the rationality of 3%-20% coffee grounds content and the importance of drainage structure for root development.

[0222] Application Example 7: Water vapor transmission rate test.

[0223] Experimental Description: This experiment, based on GB / T 1037-2021 standard, uses the cup weight gain method to determine the water vapor transmission rate (WVT) of paper cup coating materials to evaluate their moisture-proof performance. Each group of coated paper samples was equilibrated at 23℃ and 50% RH for 24 hours before being cut into circular pieces with a diameter of 80.0 mm. A standard permeation cup with an effective permeation diameter of 50.0 mm (effective permeation area A = 0.001963 m²) was selected. 20.0 g of anhydrous calcium chloride was added to the cup and leveled. The sample was sealed using a nitrile rubber sealing ring and a clamping fixture, and it was confirmed that there was no air leakage. The permeation cups were placed in a constant temperature and humidity chamber at 38℃ and 90% relative humidity, and weighed using an analytical balance with a scale division of 0.1 mg. The mass of the permeation cups was measured at 24h, 48h, and 72h after placement in the chamber. The linear regression slope k (g / 24h) of the mass increment versus time was calculated and expressed as WVT = k / A, in g / (m²·24h). Three permeation cups were prepared in parallel for each sample group, and the average value was taken as the final result.

[0224] Table 12 Results of water vapor transmission rate test:

[0225]

[0226] Note: "-" indicates that this comparative example is not applicable. Comparative examples 6 and 9 do not change the moisture permeability of the coating.

[0227] Analysis: Water vapor transmission rate (WVT) test results show that the WVT values ​​of Examples 1-6 range from 18.0 to 32.5 g / (m²·24h), exhibiting superior moisture-blocking performance compared to common biodegradable materials. In particular, Example 4, due to the introduction of nanocellulose, saw its WVT value decrease to 18.0 g / (m²·24h). In contrast, Comparative Example 2 (PLA) and Comparative Example 3 (pure PHB) had WVT values ​​as high as 96.8 and 88.2 g / (m²·24h), respectively, indicating that the unmodified bio-based material had poor moisture-blocking properties. Data from Comparative Examples 5, 10, and 11 show that an imbalanced formulation or excessively high process temperature can damage the film's density, leading to a significant increase in water vapor transmission rate (42.0-65.0 g / (m²·24h)). The experimental data verify that this invention effectively improves the moisture-proof capability of the biodegradable coating through PHA / PVA compounding and filler reinforcement technology.

[0228] Application Example 8: Total Organic Fluorines (TOF) Screening Test.

[0229] Experiment Description: This experiment aims to verify the fluorine-free compliance of each component of the paper cup, ensuring that the product meets environmental and food safety requirements. The inner surface coating paper base, the bottom sealing layer, the dry film of the adhesive at the cup body seams, and the dry film of the printing ink were used as test samples. After pulverizing the samples, they were first extracted three times with deionized water to remove inorganic fluorine interference. The dried extraction residue was then subjected to oxygen bomb combustion. After the combustion products were absorbed by the absorbent, the fluoride ion content was determined using ion chromatography and converted to the total organic fluorine (TOF) content (mg / kg) in the sample. The method detection limit was set at 5 mg / kg.

[0230] Table 13 Results of Total Organic Fluorine Tests:

[0231]

[0232] Note: "-" indicates not applicable (Comparative Example 9 does not involve chemical components). Comparative Example 1 has no independent sealing section at the bottom, marked N / A.

[0233] Analysis: The total organic fluorine (TOF) content of all submitted samples (including examples and comparative examples) was below the method detection limit (5 mg / kg). This indicates that the core raw materials used in this invention, such as PHA, PVA, and nanocellulose, as well as the accompanying water-based starch adhesive and water-based ink, are free of perfluorinated or polyfluoroalkyl substances (PFAS). Although the comparative examples differed in physical properties, they all met the fluorine-free requirements in terms of chemical composition. The experimental results confirm the environmental compliance of the raw material selection in this invention and eliminate the potential risk of persistent organic pollutants.

[0234] Application Example 9: Correlation test between water retention of the sealing part and self-opening of hot beverages.

[0235] Experiment Description: This experiment aims to verify the "non-water-soluble disappearance" characteristic of the sealing section in the drainage structure to be activated at the bottom of the cup and its impact on the sealing performance of hot beverages. The experiment consists of two parts: First, the mass loss rate test of the sealing section. The cut sealing section sample was weighed after equilibration at 23℃ and 50% RH for 24 hours, then soaked in pure water at 25℃ for 24 hours. After being removed, the surface water was wiped off and dried at 60℃ to constant weight, and the mass loss rate (%) was calculated. Second, the self-opening test of hot beverages. 200mL of hot water was placed in an intact paper cup and left to stand for 4 hours at 95℃. The weakened area at the bottom of the cup was observed to see if spontaneous cracking or leakage occurred.

[0236] Table 14. Results of Water Resistance and Hot Drink Sealing Tests for the Sealing Part:

[0237]

[0238] Note: "-" indicates not applicable. N / A indicates no independent partition.

[0239] Analysis: The water resistance test results show a direct correlation between the mass loss rate of the sealing portion and the sealing performance of the paper cup. The mass loss rates of the sealing portions in Examples 1-6 were all controlled below 4.7%, and no self-opening or leakage was observed in the hot beverage test. In contrast, Comparative Example 4, using water-soluble PVA, had a mass loss rate as high as 32.0%, and the sealing portion rapidly dissolved in hot water, leading to complete seal failure (leaking 520mg). Comparative Example 5 had a sealing portion mass loss rate of 6.5% (exceeding 5%), exhibiting slight leakage. Although Comparative Examples 2 and 3 had lower mass loss rates, leakage was caused by defects in the coating itself. Comparative Example 8, although made of water-resistant material, experienced stress leakage due to excessive structural connection points. Experimental data confirms that controlling the mass loss rate of the sealing portion to ≤5% is a necessary condition for ensuring the safety of the liquid seal during the first stage of use.

[0240] Application Example 10: Verification of indicators for stabilized coffee grounds aqueous extract.

[0241] Experimental Description: This application example specifically verifies the physicochemical properties of stabilized coffee grounds, a core raw material for seedling substrates. The experiment compared stabilized coffee grounds prepared using the "3-wash + heat treatment" process described in this invention, semi-stabilized coffee grounds that underwent only one wash (Control A), and untreated fresh coffee grounds (Control B). Test indicators included moisture content (GB / T462-2023), conductivity of the water extract (25℃, solid-liquid ratio 1:10), and the mass fraction of soluble solids in the water extract. This experiment aims to ensure that coffee grounds added to the substrate will not inhibit plant growth or cause mold growth due to excessive salt content or too much soluble matter.

[0242] Table 15 Test data of coffee grounds raw materials:

[0243]

[0244] Note: Examples 1-6 and Comparative Examples 1-15 (except Comparative Example 9) all used the "stabilized coffee grounds" in this table as raw materials. This table is for raw material verification and does not correspond to specific paper cup finished product numbers.

[0245] Analysis: Raw material validation experiments showed that the processing technology significantly altered the physicochemical properties of coffee grounds. Stabilized coffee grounds, after three washes and heat treatments, exhibited a conductivity reduced to 1.2 mS / cm, soluble solids reduced to 2.4 wt%, and a moisture content controlled at 9.2%. In contrast, untreated control B had a conductivity as high as 4.8 mS / cm and soluble solids of 8.5 wt%, posing a risk of high salt content and easy spoilage. Control A, after only one wash, fell between the two in terms of various indicators, but still did not meet the requirement of conductivity ≤1.5 mS / cm. Experimental data indicate that the stabilization process of this invention can effectively remove soluble salts and small-molecule organic matter from coffee grounds, ensuring they meet the safety requirements for seedling substrates.

[0246] Application Example 11: PHA / PVA quality ratio boundary verification.

[0247] Experimental Description: This application example aims to verify the necessity of the key parameter "≥6:1" PHA to PVA mass ratio in biodegradable barrier coatings by comparing specific formulation samples. In-depth analysis is primarily based on data from Application Example 1 (barrier performance) and Application Example 4 (migration). Example 1 (PHA / PVA = 6.1:1) and Example 2 (PHA / PVA = 12.9:1), meeting the required ratio, were selected as positive controls, while Comparative Example 5 (5.0:1) was selected as a negative control.

[0248] Table 16 shows the verification results of the PHA / PVA ratio in Application Example 11:

[0249]

[0250] Note: "-" indicates that this ratio parameter is not available or is not applicable (e.g., PE / PLA / preprocessing comparison ratio).

[0251] Analysis: Formulation ratio validation data shows a clear performance inflection point for the PHA / PVA mass ratio. Examples 1-6 all had mass ratios above 6:1, exhibiting stable barrier properties (Cobb ≤ 13.0 g / m²) and low migration. However, when this ratio decreased to 5.0:1 (Comparative Example 5), the coating Cobb value surged to 24.0 g / m², with a leakage of 35 mg and a relatively high migration of 9.6 mg / dm². This indicates that excessively high hydrophilic PVA content disrupts the barrier network of the hydrophobic PHA continuous phase. On the other hand, although Comparative Example 15 had a much higher ratio than 6:1, the low total PVA content (<0.1 parts) led to uneven dispersion, also causing a performance decline. Experimental results confirm that a PHA / PVA mass ratio ≥ 6:1 is a key formulation parameter for ensuring the stability of the coating in a hydrothermal environment.

[0252] Application Example 12: Boundary verification of the number of structural connection points.

[0253] Experimental Description: This application example primarily verifies the rationality of the structural parameters in the bottom drainage structure to be activated, which involves "setting 3 to 8 discontinuous connection points along the circumference of the concentric annular weakening zone." Data from Application Example 1 (Sealing Performance) and Application Example 2 (Activation Force) are mainly cited. The paper base, coating formulation, bottom laser micropore array parameters (pore diameter 100μm, pore spacing 400μm, array diameter 12.0mm), weakening line center circle diameter (20.0mm), weakening line width (0.6mm), and sealing method (Method A sealing coating, dry film thickness 15μm) of the boundary verification sample are all consistent with the "Preparation Method of Convertible Seedling Cup." The only difference lies in the number of discontinuous connection points along the circumference of the concentric annular weakening zone: Sample-3 has 3 connection points, each 1.0mm wide and evenly distributed; Sample-8 has 8 connection points, each 1.0mm wide and evenly distributed. They were named Implementation Sample-3 and Implementation Sample-8 respectively, and the data of all embodiments and comparative examples were listed for comprehensive comparison.

[0254] Table 17 Verification results of the number of connection points:

[0255]

[0256] Note: "-" indicates not applicable. Comparative Example 1 is a PE coating and does not have this laser weakening structure; Comparative Example 6 was not subjected to subsequent activation tests due to insufficient drying.

[0257] Analysis: Experimental data on structural parameters revealed the balance between the number of connection points and performance. Data from the implemented samples (3 points, 8 points) and Examples 1-6 (5 points) showed that within the range of 3-8 connection points, the leakage of the paper cup was ≤1mg, and the activation bursting force remained in the ideal range of 10.5-14.8N. When the number of connection points was reduced to 2 (Comparative Example 7), although the sealing was good, the activation bursting force increased to 16.5N, increasing the difficulty of operation. When the number of connection points was increased to 9 (Comparative Example 8), although the activation force decreased (7.8N), it resulted in insufficient structural strength, leading to 15mg of structural leakage. The experimental results confirm that 3-8 connection points is the only effective structural range that balances the safety of hot beverage sealing with the convenience of activation.

[0258] Application Example 13: Blending Temperature Boundary Verification.

[0259] Experimental Description: Both Sample-1 and Sample-2 used the exact same formulation components and mass proportions as in Example 2. The order of addition, stirring speed, stirring time, pH adjustment to 7.8, and filtration to 100 μm were all consistent with the "Preparation Method of Coating Composition." The only difference was the temperature control conditions during polymer blending and subsequent addition: the blending temperature for Sample-1 was 30℃, and for Sample-2 it was 50℃. A comparison was made with Comparative Example 10, prepared at 65℃. The stability of the coating solution was determined by its appearance after standing at room temperature for 24 hours: no visible layering and no gel blocks were considered "no layering," while the appearance of a clear layering interface or visible gel blocks was considered "layering / geling." The main focus was on the stability of the coating solution (observed after 24 hours) and the barrier properties (Cobb value and leakage) after film formation.

[0260] Table 18 Validation results of blending temperature:

[0261]

[0262] Note: "-" indicates not applicable. Comparative Examples 1 and 2 are based on a coating process and do not involve emulsion blending stability; Comparative Example 6 did not undergo subsequent barrier testing due to differences in the drying process.

[0263] Analysis: Process temperature experiments show that temperature control plays a decisive role in the microstructure and properties of the coating. Coatings prepared within the 30-50℃ range (Examples 1, 2, and Examples 1-6) maintained stable dispersions without stratification for 24 hours, exhibited no leakage after film formation, and displayed good Cobb value consistency. However, when the temperature increased to 65℃ (Comparative Example 10), the coating liquid showed stratification and gelation, indicating that the emulsion stability was compromised. This inhomogeneity directly led to a decrease in film-forming performance, manifested as a Cobb value increasing to 22.5 g / m² accompanied by 45 mg of leakage. Experimental data validate the necessity of blending operations at ≤50℃ to ensure coating uniformity and final barrier properties.

[0264] Application Example 14: Verification of the necessity of the component range of the barrier coating composition.

[0265] Experimental Description: This experiment systematically verifies the critical effects of the content range of each component in the coating. The performance differences between Examples 1-6 (components within the range) and Comparative Examples 11 (low PHA), 12 (high filler), 13 (high plasticizer), 14 (high crosslinking agent), and 15 (low PVA) are compared. Key data from Application Examples 1 and 4 are cited.

[0266] Table 19 Component Range Validation Results:

[0267]

[0268] Note: "-" indicates not applicable. Comparative Examples 1 and 2 are non-coating processes; Comparative Examples 6 and 9 do not involve changes in coating formulation; Comparative Examples 7, 8, and 10, although their formulations are within the range, failed due to structural or process variables. This table mainly compares the impact of formulation variables.

[0269] Analysis: Component content boundary verification data show that deviations from the content of any single component lead to significant performance degradation. Examples 1-6 exhibit excellent performance across all indicators. In Comparative Example 11, insufficient PHA (25 parts) prevented the formation of a continuous phase, resulting in leakage (60 mg); in Comparative Example 12, excessive filler (45 parts) disrupted film continuity, reducing adhesion to level 2 and causing leakage; in Comparative Example 13, excessive plasticizer (25 parts) exacerbated small molecule migration (total migration 13.0 mg / dm²); in Comparative Example 14, excessive crosslinking agent (12 parts) increased coating brittleness, worsened adhesion, and caused microcrack leakage; in Comparative Example 15, insufficient PVA (0.05 parts) resulted in unstable dispersion, deteriorating both water absorption and migration. The experimental data fully demonstrate that the component content ranges defined in this invention represent the scientific boundaries for ensuring synergistic coating performance.

[0270] Application Example 15: Durability and read / write reliability test of system interaction identifiers.

[0271] Experiment Description: This experiment aims to verify the functional reliability of the interactive identifiers (QR code and detachable NFC tag) on ​​paper cups after undergoing harsh environments such as hot beverage serving and store cleaning and disinfection, to support the system's traceability and interactive functions. Paper cup samples from all embodiments and comparative examples were selected (except for inapplicable items). First, a simulated hot beverage process was performed by serving the cups in 95℃ hot water for 4 hours, followed by standard store pretreatment (water rinsing, UV exposure, and 60℃ hot air drying). After treatment, the QR code was scanned using a smartphone of the same model with a camera resolution of at least 12 megapixels: the first scan was completed under indoor illumination of 500 lx, a scanning distance of 150 mm, and with the phone lens parallel to the QR code plane. If an NFC tag was provided, with the phone's NFC function enabled, the tag was placed against the NFC sensing area on the back of the phone and held for 2 seconds to complete the read and write tests. The integrity of the appearance, the first scan / read success rate (%), and the data write success rate (%) were recorded.

[0272] Table 20: Test Results of Interactive Identifiers

[0273]

[0274] Note: "-" indicates not applicable. Comparative Examples 2 and 4 could not undergo complete pretreatment and scanning tests because the paper cups suffered severe structural damage or the seal dissolved during the hot beverage stage. N / A indicates that the sample was not equipped with an NFC tag and only the QR code was tested.

[0275] Analysis: The durability test results of the interactive labels show that after undergoing hot beverage and cleaning processes, Examples 1-6 maintained a clear and undamaged appearance, and the success rate of reading and writing QR codes and NFC tags reached 100%. This confirms the excellent ink adhesion and environmental resistance of the coating surface. Comparative Example 6 suffered from insufficient pre-drying, resulting in residual water stains on the surface and causing the QR code recognition rate to drop to 85%. Comparative Example 13 also suffered from a greasy surface due to plasticizer precipitation, which also affected the recognition effect (85%). Comparative Examples 2, 3, and 4 suffered physical damage to the label carrier due to substrate material failure or coating defects. The experimental results indicate that the stability of the paper cup coating and the dryness of the pre-treatment are necessary prerequisites for ensuring the stable operation of the digital traceability system.

[0276] Experimental Results and Analysis:

[0277] Based on the test results of application examples 1-15 above, the secondary seedling paper cup recycling and conversion system and the fluorine-free barrier coating proposed in this invention have demonstrated significant performance advantages and system feasibility in the first use stage (beverage container), the second use stage (seedling container), and the end-of-life disposal stage (composting / soil placement). The following is a detailed analysis from four dimensions: core performance balance, influence trends of formulation components, critical effects of structural parameters, and system operation indicators.

[0278] Balancing and Breakthroughs in Core Performance:

[0279] Experimental data show that the paper cups of Examples 1-6 successfully overcome the contradiction between heat-resistant liquid sealing and machinability of existing biodegradable materials. In the first stage of use, thanks to the specific bio-based coating system, the paper cups exhibit excellent barrier properties (Cobb value 9.8-13.0 g / m², no leakage after 4 hours) and extremely low total migration (4.0-5.5 mg / dm²) under the action of 95°C hot water. Their performance is comparable to that of traditional PE coated paper cups (Comparative Example 1) and significantly better than PLA coated paper cups (Comparative Example 2, prone to leakage) and pure PHB coated paper cups (Comparative Example 3, poor adhesion). In the second stage of use, through the combination of laser micropores and concentric ring weakening zones, the activation breaking force of the sample samples is precisely controlled within the ergonomic comfort zone of 10.2-14.5 N, and the amount of fragments detached after activation is extremely low (≤0.6 mg), avoiding the common brittle breakage risk of PLA materials (Comparative Example 2 fragments amounted to 65.0 mg). Meanwhile, all embodiments achieved a biodegradation rate of over 88.5% under 90-day industrial composting conditions, realizing a green closed loop throughout the entire life cycle.

[0280] Analysis of the impact of changes in component content trends:

[0281] Based on the data from Examples 1-6, Comparative Examples 5, and Comparative Examples 11-15, the nonlinear influence trend of changes in the content of each component in the formulation on the coating performance can be clearly observed:

[0282] The effect of the PHA / PVA mass ratio: Experiments confirmed that "6:1" is the critical value for ensuring the water resistance of the coating. When the PHA / PVA ratio decreased from 12.9:1 (Example 2) to 5.0:1 (Comparative Example 5), the proportion of the hydrophilic PVA phase in the system exceeded the coating capacity of the hydrophobic PHA phase, resulting in a significant increase in water absorption (Cobb value increased from 12.8 to 24.0 g / m²) and triggering a leakage of 35 mg. This indicates that only when the hydrophobic PHA component is dominant (mass ratio ≥ 6:1) and the PVA dosage is within the range required for stable dispersion can a continuous, dense, and defect-controlled barrier film be obtained, thereby effectively blocking water penetration and reducing the risk of leakage.

[0283] Effect of PHA (film-forming polymer) content: As a film-forming matrix, PHA has a clear lower limit threshold for its content. When the PHA content is reduced from more than 30 parts to 25 parts (Comparative Example 11), the coating cannot form a continuous and dense film, resulting in a shortened oil resistance time of 120 min and severe leakage of 60 mg. This indicates that a sufficient amount of matrix resin (≥30 parts) must be ensured to cover the pores of the paper-based fibers.

[0284] Effect of barrier enhancement component (filler) content: The addition of filler can improve barrier properties, but excessive amounts can disrupt membrane continuity. When the amount of modified kaolin increased from 40 parts (Example 1) to 45 parts (Comparative Example 12), the coating adhesion deteriorated from grade 0 to grade 2, and 30 mg of leakage occurred. This indicates that the filler volume concentration (PVC) must be controlled below the critical volume concentration (CPVC) (≤40 parts) to avoid the formation of permeation channels.

[0285] The effect of plasticizer content: Plasticizer content is positively correlated with migration. When the amount of plasticizer increased from 20 parts (Example 1) to 25 parts (Comparative Example 13), the total migration surged from 5.5 mg / dm² to 13.0 mg / dm², exceeding the regulatory limit. Therefore, controlling the plasticizer content within the range of 0–20 parts is necessary to balance flexibility and food safety.

[0286] The effect of PVA content: As a dispersant and stabilizer, excessively low PVA content can lead to emulsification failure. When the PVA content decreased from more than 0.1 parts to 0.05 parts (Comparative Example 15), the stability of the dispersion system decreased, the number of microscopic defects after film formation increased, and the Cobb value increased to 23.0 g / m². This verifies that a PVA content of 0.1–4.9 parts is indispensable for maintaining emulsion stability and film density.

[0287] Critical effects of structural parameters and process conditions:

[0288] Number of connection points: Experimental data (Application Example 12) revealed that "3 to 8" connection points are the only solution that balances sealing and activation. Fewer than 3 connection points (Comparative Example 7) resulted in excessive activation force (16.5 N) and poor drainage; more than 9 connection points (Comparative Example 8) were easy to activate but caused structural leakage.

[0289] Water resistance of the sealing section: The mass loss rate of the sealing section must be controlled within 5% (Application Example 9). If water-soluble materials are used (Comparative Example 4, loss rate 32%), although it is beneficial for drainage, it will dissolve and become ineffective during the hot beverage stage, which will not only make it impossible to hold beverages, but may also cause food safety incidents.

[0290] Blending temperature: Temperature control is the core of the process (Application Example 13). Temperatures exceeding 50°C (e.g., 65°C, Comparative Example 10) can cause bio-based emulsions to demulsify, separate, or gel, directly leading to a significant decrease in the barrier properties of the coating.

[0291] Feasibility verification of system operation indicators:

[0292] System-level testing validated the key parameters of closed-loop operation. In store pre-processing, setting a standard of "residual moisture ≤ 0.30g / cup" (Application Example 5) effectively controlled the total bacterial count within a safe range, preventing secondary contamination. During the seedling stage, controlling the coffee grounds content between 3% and 20% (Application Example 6) both utilized waste and promoted plant growth; exceeding 20% ​​significantly inhibited germination rate and plant height. Furthermore, water and heat resistance tests on the interactive label (Application Example 15) demonstrated the good printability of the coating surface, ensuring the stable operation of the digital traceability system.

[0293] In summary, this invention, through precise control of the biodegradable coating formulation components, innovative design of the cup bottom microstructure, and standardized definition of the system operation process, successfully constructs a closed-loop system that meets the stringent performance requirements of disposable beverage containers while possessing efficient secondary seedling conversion capabilities. This solution technically addresses the pain points of traditional biodegradable material applications and commercially provides a new path for the high-value utilization of waste, demonstrating significant environmental benefits and promotional value.

[0294] Those skilled in the art should understand that the above embodiments are merely exemplary and are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the technical solutions of the present invention within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A paper cup secondary utilization convertible nursery container system characterized by, The system is used to convert used disposable beverage cups into seedling cups after the first use stage. The used disposable beverage cups are seedling cups with a biodegradable barrier coating and a drainage structure to be activated. In the first use stage, they serve as beverage containers, and in the second use stage, after drainage activation, they function as seedling cups. The system includes: The diversion and recycling module is used to receive and divert the used disposable beverage paper cups. The residual liquid control and pretreatment module is used to perform one or more of the following treatments on the used disposable beverage paper cups: residual liquid removal, rinsing, wiping, drying, and disinfection, and to keep the inner surface of the used disposable beverage paper cups in a dry state as if filled with seedling substrate. The dry state means that there is no visible water film on the inner surface of the paper cup and the residual moisture is ≤0.30g / cup. The drainage activation and seedling filling module is used to activate the drainage structure to be activated under the constraint of the positioning head or the limiting tool to form a drainage channel, and to fill the used disposable beverage paper cup with seedling substrate and seeds. Kit delivery module for providing individually packaged substrate components and seed modules; The user interaction and traceability module includes one or more of a barcode scanning terminal, a near-field communication reading and writing terminal, or an RFID reading and writing terminal. It is used to record information including at least the paper cup batch, store identification, recycling time, pretreatment status, kit type, and user operation records through interactive identifiers, and output planting guidance information. The composting or soil return module is used to output information on the composting or soil degradation treatment of the seedling cups after the seedlings have been raised. The aforementioned transformation seedling cup includes: Paper-based cup body, including the cup body and the cup base; A biodegradable barrier coating is disposed on the inner surface of the paper-based cup body. The biodegradable barrier coating is a continuous film layer formed by an aqueous coating composition. The biodegradable barrier coating contains a polyhydroxyalkanoate film-forming component and a polyvinyl alcohol dispersion stabilizing component. The mass ratio of polyhydroxyalkanoate to polyvinyl alcohol in the biodegradable barrier coating is ≥6:1 by weight of solids. It is used to form a barrier against liquids in the first stage of use. The drainage structure to be activated is set at the bottom of the cup. The drainage structure to be activated includes a preset weakening area and a sealing part. The preset weakening area is a combination of a laser micro-hole array area and a concentric ring weakening area. The concentric ring weakening area is provided with 3 to 8 discontinuous connection points along the circumference. The sealing portion is a biodegradable sealing coating located in the preset weakened area, and the sealing coating and the biodegradable barrier coating are formed from the same water-based coating composition. In the first use stage, the sealing portion covers or seals the preset weakened area and together with the biodegradable barrier coating forms a bottom liquid sealing structure. The mass loss rate of the sealing portion after soaking in pure water at 25°C for 24 hours is ≤5%. In the second stage of use, the preset weakened area is changed from a closed state to a drainage state by pressing, piercing, tearing or pulling ring opening operation under the action of 10N to 15N external force, so as to form no less than 3 drainage channels connecting the inside of the cup to the outside world for seedling drainage. After activation, the sealing part remains connected to the bottom of the cup to form a folding piece or folding ring to prevent fragments from falling off. The mass of the fragments falling off is ≤5mg.

2. The convertible seedling container system for the reuse of paper cups according to claim 1, characterized in that: The diversion and recycling module includes a limiting structure, an anti-misdisposal structure, a diversion structure, or a visual prompt structure. The residual liquid control and pretreatment module includes a residual liquid volume determination structure, as well as one or more of the following: a rinsing table or spraying structure, a water absorption or draining structure, a wiping structure, a hot air drying structure or a room temperature air drying structure, a disinfection structure, and a closed temporary storage structure. The drainage activation and seedling filling module includes a positioning pressure head or a limiting tooling, which is used to make the activation operation occur at a preset position and improve the consistency of activation. The kit dispensing module further provides a biodegradable base or diversion tray to receive exudate for exudate management and secondary irrigation during the seedling stage.

3. The paper cup secondary utilization convertible nursery container system of claim 1, wherein, The dry film thickness of the biodegradable barrier coating is 20 μm, and the dry film thickness of the sealing coating is 15 μm.

4. The convertible seedling container system for the reuse of paper cups according to claim 1, characterized in that, The biodegradable barrier coating meets one or more of the following properties: When exposed to hot water at 95℃ for 30 minutes, the water absorption of the product is ≤13.0g / m². After being filled with 200mL of hot water at an initial temperature of 95℃ and left to stand for 4 hours, the leakage of the cup was 0mg. Furthermore, under the migration conditions of using 10wt% ethanol aqueous solution as a food simulant and maintaining the temperature at 70℃ for 2 hours, the total migration amount was ≤5.5mg / dm².

5. The paper cup repurposed convertible nursery container system of claim 1, wherein, The laser micro-hole array region is a circular area with a diameter of 12.0 mm. The diameter of the micro-holes in the laser micro-hole array region is 100 μm and the spacing between the micro-holes is 400 μm. The diameter of the central circle of the weakening line in the concentric annular weakening region is 20.0 mm and the width of the weakening line is 0.6 mm.

6. The paper cup repurposed convertible nursery container system of claim 1, wherein, The concentric annular weakening zone is evenly provided with 5 discontinuous connection points along the circumference, and each connection point is 1.0 mm wide. The drainage structure to be activated includes a pull-ring type activation component, wherein the outer diameter of the pull-ring is 15mm; The mass of the detached fragment is ≤5mg.

7. The convertible seedling container system for the reuse of paper cups according to claim 1, characterized in that, The outer surface of the paper-based cup is provided with a conversion prompt label, which includes an interactive label, and the interactive label is one or more of the following: a QR code, a barcode, a near-field communication tag, or a radio frequency identification tag. When the interaction identifier is a near-field communication tag or a radio frequency identification tag, the tag is a detachable structure or is set on an outer sleeve that is detachably connected to the paper-based cup body; The conversion seedling cup is a biodegradable structure suitable for composting. The conversion seedling cup consists of a paper-based cup body, a biodegradable barrier coating, a cup body seam adhesive, and an outer surface printed ink. Under aerobic controlled composting conditions at 58℃, the disintegration rate is ≥92.5% after 45 days and the biodegradation rate is ≥88.5% after 90 days. The total organic fluorine content of the paper-based cup body, biodegradable barrier coating, adhesive, and printing ink is ≤5mg / kg.

8. A nursery kit characterized by, include: Transformation seedling cup, wherein the transformation seedling cup is the transformation seedling cup according to any one of claims 1 to 7; The substrate component is individually packaged and contains a mixture of stabilized coffee grounds obtained through water washing, heat treatment, and subsequent drying, and a seedling substrate. The stabilized coffee grounds have a moisture content ≤10%; the aqueous extract of the stabilized coffee grounds has a conductivity ≤1.5 mS / cm and a soluble solids content ≤3.0% by mass; the volume fraction of stabilized coffee grounds in the substrate component is 3%–20%; the seedling substrate is selected from one or more of coconut coir, perlite, or vermiculite. Seed module, comprising one or more plant seeds and a biodegradable carrier; The planting guidance component provides information on sowing depth, watering frequency, and light parameters. An activation tool component, which is one or more of a positioning pressure head, a disposable pressing needle, or a limiting tool, is used to standardize and activate the preset weakened area of ​​the drainage structure to be activated in the transformation seedling cup to form a drainage channel. An exudate management component, which is a biodegradable base or a diversion tray, is used to collect exudate during the seedling stage and for secondary irrigation.

9. The nursery kit of claim 8, wherein, The stabilized coffee grounds are obtained through the following steps: Fresh coffee grounds are added to drinking water or deionized water, mixed at a ratio of coffee grounds wet weight: water volume = 1:10 (g:mL), and mechanically stirred for 5 minutes. The mixture is then drained and washed three times in the same manner. The washed coffee grounds are spread on a tray with a thickness ≤10mm, placed in a forced-air drying oven at 105℃ for 2 hours, and then cooled to room temperature. The heat-treated coffee grounds are then dried in a forced-air drying oven at 70℃ until the moisture content reaches 8%, and then sealed to obtain stabilized coffee grounds.

10. A method of directly reusing a single-use paper drinking cup as a nursery cup, characterized by, The seedling cup is the conversion seedling cup according to any one of claims 1 to 7, and includes the following steps: Step 1: After emptying the paper cups of residual liquid at the end of the first stage of use, put them into the diversion and recycling device to collect the recycled paper cups and read the interactive mark on the outer surface of the paper cups to record the batch, store mark and recycling time of the paper cups; Step 2: Spray purified water, deionized water, or drinking water into the paper cups recycled in Step 1 using a rinsing station and wipe them. Then, disinfect and dry them to ensure that the inner surface of the paper cups is dry. The dry state means that there is no visible water film on the inner surface of the paper cups and the residual moisture is ≤0.30g / cup. The pre-treated paper cups are obtained, and the data including at least the pre-treatment state and the dry state compliance information are bound and recorded with the interactive identifier. Step 3: Place the pre-treated paper cup from Step 2 into a limiting fixture and press the weakened area at the bottom of the cup under an external force of 10N to 15N, so that the sealing part is folded over and forms no less than 3 drainage channels. After activation, the sealing part remains connected to the bottom of the cup to prevent fragments from falling off. The mass of the fragments falling off is ≤5mg, thus obtaining a drainage activated paper cup. Step 4: Add the individual packaging matrix component into the paper cup activated by drainage in Step 3 and gently press and level it to obtain the matrix-filled paper cup; Step 5: Place the seed module on the surface of the substrate-filled paper cup from Step 4, and cover it with seedling substrate to the predetermined sowing depth to obtain the sowing paper cup; Step 6: Water the seeding cups from Step 5 until the substrate is moist, and place them in a temperature range of 20℃~30℃ and a light source of 12h~16h to obtain seedling cups; Step 7: After the seedlings are grown, compost or bury the seedling cups from Step 6 along with the substrate to obtain recycled materials.

11. The method of claim 10, wherein, Step 2 includes natural air drying, hot air drying, drying assisted by water-absorbing materials, or a combination thereof; Step 2 involves disinfection using at least one of ultraviolet light, steam, heat treatment, or ozone. In any of steps 1 to 7, the interaction identifier is read and the traceability data record bound to the interaction identifier is written or updated to realize the issuance record, user points, growth check-in or batch traceability. The traceability data to be written or updated includes at least information on whether the pre-processing status and the dryness status meet the standards.

12. A biodegradable barrier coating composition for convertible nursery cups, characterized in that, The conversion seedling cup is the conversion seedling cup according to any one of claims 1 to 7, and the composition is an aqueous system comprising, by solid components: The film-forming polymer component comprises 30 to 95.2 parts by weight, wherein the film-forming polymer component comprises polyhydroxy fatty acid ester and optionally further comprises at least one biodegradable film-forming polyester; Polyvinyl alcohol 0.1–4.9 parts by weight; Barrier reinforcement component: 0-40 parts by weight; Plasticizing component: 0-20 parts by weight; 0-5 parts by weight of the crosslinking curing component, wherein the crosslinking curing component is selected from silane coupling agents; 0-5 parts by weight of wetting, defoaming and rheology modifier, wherein the wetting, defoaming and rheology modifier includes alkyl polysaccharide wetting agent, defoaming agent and hydroxyethyl cellulose thickener; Furthermore, based on solid mass, the mass ratio of polyhydroxyalkanoate to polyvinyl alcohol in the composition is ≥6:1; The total organic fluorine content of the composition is ≤5 mg / kg; The mass loss rate of the film formed by drying the composition is ≤5% when immersed in pure water at 25°C for 24 hours.

13. The biodegradable barrier coating composition for convertible nursery cups of claim 12, wherein, The polyhydroxyalkanoate is selected from short-chain polyhydroxyalkanoates, medium- and long-chain polyhydroxyalkanoates, or copolymers between monomers that form short-chain polyhydroxyalkanoates and monomers that form medium- and long-chain polyhydroxyalkanoates. The short-chain polyhydroxy fatty acid ester is selected from one or more of poly3-hydroxybutyrate, poly3-hydroxybutyrate-co-3-hydroxyvalerate, and poly3-hydroxybutyrate-co-4-hydroxybutyrate; The medium- and long-chain polyhydroxy fatty acid esters are selected from one or more of poly(3-hydroxyhexanoate), poly(3-hydroxyheptanoate), poly(3-hydroxyoctanoate), poly(3-hydroxynonanoate), poly(3-hydroxydecanoate), poly(3-hydroxyundecanoate), poly(3-hydroxydodecanate), poly(3-hydroxytetrate), poly(3-hydroxytridecanate), poly(3-hydroxytetradecanoate), and their copolymers or blends. The biodegradable film-forming polyester is selected from one or more of the following: polyester obtained by polycondensation of succinic acid and 1,4-butanediol; polyester obtained by ring-opening polymerization of lactic acid or lactide; polyester obtained by ring-opening polymerization of ε-caprolactone; or combinations thereof.

14. The biodegradable barrier coating composition for convertible seedling cups according to claim 12, characterized in that, The barrier reinforcement component is selected from nanocellulose, flaky mineral filler, or a combination of the two; wherein the flaky mineral filler is selected from one or more of unmodified kaolin and modified kaolin.

15. The biodegradable barrier coating composition for convertible nursery cups of claim 12, wherein, The preparation of the composition includes: blending a polyhydroxyalkanoate aqueous emulsion with an optional polybutylene succinate aqueous emulsion at 40°C for 15 min to obtain a polymer mixture; adding a polyvinyl alcohol aqueous solution to the polymer mixture at 40°C and continuing to stir for 15 min; adding a barrier reinforcing component after pre-dispersing it with water and dispersing it under high shear; mixing a crosslinking curing component with water and adjusting the pH to 4.5 with glacial acetic acid, allowing it to stand for 30 min to obtain a silane hydrolysate; then adding the silane hydrolysate dropwise to the blending system at 30°C and adjusting the final pH to 7.8 to obtain a coating solution; adjusting the total solids content of the coating solution to 40 wt% and filtering it through a 100 μm filter.

Images