Mesoporous degradable composite fiber cloth containing tea leaf residues and preparation method of mesoporous degradable composite fiber cloth

Abstract

The invention discloses a mesoporous degradable composite fiber cloth containing tea residue and a preparation method thereof, the mesoporous degradable composite fiber cloth containing tea residue comprises a functional plain weave fabric woven by core-sheath structure composite fibers, the core-sheath structure composite fibers are composed of a core layer and a sheath layer, the core layer part is prepared from the following components in percentage by mass: 28.0 to 30.4 weight percent of tea residue particles with natural mesoporous structures, 32.2 to 36.4 weight percent of polylactic acid, 13.2 to 19.8 weight percent of poly (butylene succinate) and 0.6 to 0.8 weight percent of maleic anhydride grafted polylactic acid compatilizer; the sheath layer part comprises the following components in percentage by weight: 10 to 12 percent of poly (propylene succinate), 4 to 6 percent of polyethylene glycol and 2 to 3 percent of polymaleic anhydride. The problems of migration, non-degradability and ecological potential safety hazards of a traditional antibacterial agent are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of box-type transformers, and in particular to a mesoporous degradable composite fiber cloth containing tea residues and a preparation method thereof. Background Art

[0002] With the rapid development of biodegradable materials and green textile technologies, more and more research is devoted to the resource utilization of agricultural waste to develop new environmentally friendly fiber materials. Among them, biodegradable polyesters such as polylactic acid and polybutylene succinate are gradually becoming important options for green alternative materials for textiles due to their good film-forming properties and compostability. However, the current technical routes still face the following key issues in practical application:

[0003] First, there are significant polarity differences in the blending process of biomass fillers and biodegradable polyesters. Plant fiber particles such as tea leaves, bamboo fibers, and wood powder contain a large number of hydroxyl groups and aromatic structures, and have poor interfacial compatibility with polylactic acid and PBS polyester matrices, which can easily lead to stress concentration in the composite fiber structure and the formation of microcracks, which ultimately manifest as problems such as decreased fiber breaking strength, high slag shedding rate, and poor washability of the finished fabric.

[0004] Secondly, the functional development of existing biodegradable fiber fabrics mainly relies on post-finishing processes. For example, antibacterial and deodorizing properties are given by spraying silver ions, quaternary ammonium salts or nano zinc oxide on the surface. However, this type of treatment method generally has hidden dangers such as complex processing, heavy metal residues, antibacterial agent leakage and non-biodegradability. It not only poses risks to human safety, but also produces microplastics and toxic accumulation problems after use, and cannot meet the sustainable standards of ecological textiles. Even if some studies have tried to use natural plant extracts such as tea polyphenols and chitosan for finishing, it is still difficult to achieve long-term and safe antibacterial functions due to the characteristics of difficult stable fixation inside the fiber and uncontrollable release rate.

[0005] In summary, the existing technology has significant shortcomings in improving the interfacial bonding strength between biomass fillers and polyester matrices, achieving functional stable implantation, and retaining the natural microporous structure to enhance climate adaptability. It is urgent to propose a new solution that takes into account the stability of fiber structure, green processing path and terminal fabric performance. Summary of the Invention

[0006] One purpose of the present invention is to provide a mesoporous degradable composite fiber cloth containing tea residue and a preparation method thereof. The present invention effectively solves the migration, non-degradability and ecological safety risks of traditional antibacterial agents.

[0007] A mesoporous degradable composite fiber cloth containing tea residue according to an embodiment of the present invention comprises a functional plain fabric woven from core-sheath structure composite fibers, wherein the core-sheath structure composite fibers are composed of a core layer and a sheath layer, and the content of each component by total mass is:

[0008] The core layer comprises 28.0-30.4 wt% of tea residue particles with natural mesoporous structure, 32.2-36.4 wt% of polylactic acid, 13.2-19.8 wt% of polybutylene succinate, and 0.6-0.8 wt% of a maleic anhydride grafted polylactic acid compatibilizer.

[0009] The sheath layer comprises 10-12 wt% of polypropylene succinate, 4-6 wt% of polyethylene glycol, and 2-3 wt% of polymaleic anhydride;

[0010] The core layer and the sheath layer form a continuous interface through melt co-extrusion process, and the molar mass of the sheath elastomer structure is 6.2×10 4 ~8.5×10 4 g / mol, the whole fiber has a mesopore size distribution of 2-20 nm and a specific surface area of ​​20-30 m 2 g -1 Multi-level channel network, breaking strength ≥ 280N.

[0011] A method for preparing a mesoporous biodegradable composite fiber cloth containing tea residues comprises the following steps:

[0012] S1. Wash the tea leaves with clean water at room temperature until the conductivity of the extract is no higher than 200μScm -1 , and then freeze-dried at -40 to -35°C and a vacuum degree of 20 to 22 Pa for 12 to 14 hours to obtain dry tea residues with a natural mesoporous structure;

[0013] S2. Dry tea residue at a shear rate of ≤800s -1 The tea residue is ground into a particle size of 40 μm to 100 μm in a jet mill to obtain tea residue particles with a mesoporous structure;

[0014] S3. The tea residue particles were kept in a mesoporous structure and the maleic anhydride grafted polylactic acid compatibilizer was dispersed in ethyl lactic acid at a mass ratio of 98:2 to 98.2:1.8 at 60 to 62 ° C and stirred at 300 to 310 rpm for 30 to 35 min to form a compatibility layer on the surface of the tea residue particles to obtain compatible tea residue particles.

[0015] S4. The compatibilized tea residue particles 35-38 wt% and polylactic acid / polybutylene succinate blend matrix 62-65 wt% were added together to melt blend in a twin-screw extruder at a temperature of 175 ℃ ~ 185 ℃, a screw speed of 150-160 rpm, and a residence time of 2.5-3 min to obtain a tea residue blend masterbatch maintaining a mesoporous structure;

[0016] S5. The tea residue blended masterbatch with a mesoporous structure was dried at 80-82°C for 4-4.5 hours as the core material, and then mixed with 20 wt% of polypropylene succinate-polyethylene glycol-polymaleic anhydride elastomer as the sheath material. The mixture was melt-spinned at a temperature of 200-205°C and a draw ratio of 3.5-3.6, and then cooled in a water bath at 20-22°C to obtain tea residue core-sheath filaments with a mesoporous structure.

[0017] S6. The tea residue core-sheath filaments, which retained a mesoporous structure, were subjected to a primary stretching at 60-65°C and a secondary stretching at 90-96°C, with a total stretching ratio of 1.8. The filaments were then heat-set at 120-122°C for 30 seconds to solidify the mesoporous-capillary channel network, yielding functional fiber filaments.

[0018] S7. Use functional fiber filaments as warp yarns (280-300 strands / 10cm) and weft yarns (240-260 strands / 10cm) to weave plain grey fabric, with weaving tension controlled at 35 cNtex. -1 ;

[0019] S8. The plain grey fabric was surface activated with 40W low-temperature plasma for 2 minutes, then dyed in a natural theabrownin dye solution at 70-75°C for 20 minutes with a wet pick-up rate of 85-86%. The fabric was then dried with hot air at 90-92°C for 5-6 minutes to obtain a biodegradable and environmentally friendly fabric with climate adaptability.

[0020] Optionally, the S1 step specifically includes:

[0021] S11: The tea residue is sequentially soaked and washed three times at room temperature with deionized water, each soaking volume ratio is 1:10, the washing time is 20-30 minutes, and the stirring speed is 250-300 rpm, until the conductivity of the obtained extract is no higher than 200 μScm -1 The obtained tea residue was filtered through a 0.2 mm filter and collected;

[0022] S12: spreading the washed tea residues on a corrosion-resistant metal plate, placing the plate in a freeze-drying apparatus, and freeze-drying the plate at a temperature of -40 to -35°C and a vacuum of 20 to 22 Pa for 12 to 14 hours, until the moisture content of the tea residues is less than 2%, thereby obtaining a dry tea residue raw material with a natural mesoporous structure.

[0023] The main components of the dried tea residue in S13 are cellulose, lignin and residual tea polyphenols, and the mass fractions of each component are 38-48% of cellulose, 19-24% of lignin and 5-8% of tea polyphenols.

[0024] Optionally, the step S2 specifically includes:

[0025] S21 will maintain the natural mesoporous structure of dry tea residue raw materials in a relative humidity not higher than 30%, temperature 25 ~ 28 ℃ dry environment pre-stored 2 ~ 3h, to ensure that the moisture content is stable below 2%;

[0026] S22. Use feed inlet pressure of 0.6-0.8MPa and shear rate ≤800s -1 The dry tea residues are ground by a jet mill. The speed of the classifying wheel of the jet mill is set at 2800-3200 rpm. The final particle size distribution of the tea residues is controlled to be between 40 μm and 100 μm, and tea residue particles with a natural mesoporous structure are obtained.

[0027] S23. The tea residue particles maintain a natural mesoporous structure, with a pore size range of 2 to 20 nm and a mesopore ratio of not less than 85% of the total pore structure, and a specific surface area of ​​20 to 30 m 2 g -1 , particle size distribution D 50 The value is 68~72μm.

[0028] Optionally, the S3 step specifically includes:

[0029] S31 take tea residue particles to maintain the natural mesoporous structure and maleic anhydride grafted polylactic acid compatibilizer, according to the mass ratio of 98:2 ~ 98.2:1.8 were weighed;

[0030] S32 tea residue particles and maleic anhydride grafted polylactic acid compatibilizer was slowly added to the ethyl lactic acid solution at a constant temperature of 60 to 62 ° C, the stirring speed was controlled at 300 to 310 rpm, the continuous stirring time was 30 to 35 min, so that the maleic anhydride grafted polylactic acid was uniformly adsorbed and coated on the surface of the tea residue particles to form an interfacial compatibility layer;

[0031] S33. The tea residue particles after compatibilization treatment were vacuum filtered through 0.45 μm and dried in a vacuum drying oven at 45-50°C for 4-5 hours. The resulting product had a polylactic acid-maleic anhydride coating layer on its surface.

[0032] Optionally, the S4 step specifically includes:

[0033] S41. 35 to 38 wt% of tea residue particles having a polylactic acid - maleic anhydride coating layer are uniformly mixed with 62 to 65 wt% of a biodegradable polyester blend matrix, wherein the biodegradable polyester blend matrix is ​​pre-blended with polylactic acid and polybutylene succinate in a mass ratio of 65:35 to 70:30;

[0034] S42. The mixture was continuously fed into a twin-screw extruder having a screw diameter of 35 to 40 mm and an aspect ratio of 32:1, the melt temperature was set to 175 to 185 ° C, the screw speed was 150 to 160 rpm, the material residence time was 2.5 to 3 min, and melt blending was performed under a nitrogen atmosphere;

[0035] S43. During the blending process, the extrusion shear rate was controlled to be 80-120s -1 , so that the tea residue particles maintain their natural mesoporous structure, while the interface coating layer undergoes segment embedding and compounding with the polyester matrix under the action of heat, forming a tea residue modified blend melt with a mesoporous structure and a thermally stable interface;

[0036] S44. The obtained tea residue modified blend melt was treated by water cooling granulation, with a shear frequency of 30 to 40 cut s -1 The particle size is controlled between 2 and 3 mm to obtain a tea residue blending masterbatch with a mesoporous structure.

[0037] Optionally, the step S5 specifically includes:

[0038] S51. The tea residue blended masterbatch with a mesoporous structure is placed in a hot air drying oven with a set temperature of 80-82°C and an air flow velocity of 0.3-0.4 m / s for 4-4.5 h until no visible water vapor condenses on the surface of the masterbatch to obtain a dry core spinning material;

[0039] S52. Take the dried core spinning material as the core raw material and feed it together with the sheath raw material. The sheath raw material is a polypropylene succinate - polyethylene glycol - polymaleic anhydride elastomer accounting for 20 wt% by mass;

[0040] S53. The core layer raw material and the sheath layer raw material are fed into the core-sheath composite melt spinning system, and the core layer heating zone temperature is set to 200-203 ° C, the sheath layer heating zone temperature is 203-205 ° C, the main pump flow rate ratio is core layer: sheath layer = 4:1, the spinneret aperture is 0.4 mm, and the extrusion pressure is 12-15 MPa;

[0041] S54. After the melt is extruded through the spinneret assembly, it enters a water bath at 20-22°C for cooling and solidification, and then is directional stretched by a stretching roller group. The stretching ratio is set to 3.5-3.6, and the total stretching speed is 220-240 m / min to obtain tea residue core-sheath filaments with a mesoporous structure. The core layer of the filament is a tea residue polyester composite phase, and the sheath layer is a PBS-polyethylene glycol-PMG elastomer phase. The overall structure maintains the same mesoporous specific surface area characteristics as step S23 in claim 3.

[0042] Optionally, the preparation of the polypropylene succinate-polyethylene glycol-polymaleic anhydride elastomer comprises the following steps:

[0043] Succinic acid and 1,3-propylene glycol are added to a reactor in a molar ratio of 1:1.1, 0.3-0.5 wt% of tetrabutyl titanate is added as a catalyst, and an esterification reaction is carried out at 180-190° C. for 3-4 hours. The water generated by the reaction is recovered to obtain a polypropylene succinate prepolymer;

[0044] The poly(propylene succinate) prepolymer is cooled to 160-170° C., polyethylene glycol with an average molecular weight of 2000-4000 is added, and the added weight proportion of polyethylene glycol is 20-30 wt%. The polycondensation reaction is carried out under nitrogen protection for 2-3 hours to obtain a PBS-polyethylene glycol block prepolymer.

[0045] A 1-3 wt% acetone solution of maleic anhydride is added dropwise to the PBS-polyethylene glycol block prepolymer and the reaction is continued at 100-120°C for 2 hours to allow the epoxy groups of the maleic anhydride to graft onto the hydroxyl groups of the polyethylene glycol, forming a block elastomer molecular chain structure with active side groups.

[0046] The block elastomer molecular chain structure with active side groups was precipitated with ethanol and vacuum dried for 12 h to obtain poly(propylene succinate)-poly(ethylene glycol)-poly(maleic anhydride) elastomer with a molar mass of 6.2×10 4 ~8.5×10 4 g / mol, used as sheath material.

[0047] Optionally, the step S6 specifically includes:

[0048] S61. The tea residue core-sheath filaments with a mesoporous structure are fed into a drawing system and drawn once in a hot roller set at a temperature of 60 to 65°C. The drawing speed is set to 80 to 100 m / min and the draw ratio is controlled to 1.3 to 1.4 times to eliminate lattice defects in the nascent fibers and preliminarily orient the molecular segments.

[0049] S62. The tea residue core-sheath filaments after primary drawing are continuously fed into a second set of heated rollers at a temperature of 90-96°C for secondary drawing. The drawing speed is set at 180-200 m / min, and the draw ratio is controlled at 1.3-1.4 times to align the stress directions of the core and sheath layers and form a stable mesoporous-capillary network structure.

[0050] S63. The tea residue core-sheath filaments, after secondary drawing, were heat-set in a heat-setting apparatus at 120-122°C for 30 seconds to stabilize the polylactic acid / polybutylene succinate blend and the PBS-polyethylene glycol-PMG elastomer under thermal-tensile stress.

[0051] S64. After heat setting, the filaments are cooled to room temperature and relaxed and wound up. The pore size distribution in the core layer of the obtained fiber filaments is maintained in the range of 2 to 20 nm, and the specific surface area is maintained in the range of 20 to 30 m 2 g -1 , fiber breaking strength ≥280N.

[0052] The beneficial effects of the present invention are:

[0053] The present invention, based on the pretreatment of tea residues and screening of crushed particle size, adopts maleic anhydride grafted polylactic acid compatibilizer and disperses and coats the surface through ethyl lactic acid to precisely control the surface polarity of tea residue particles, thereby realizing multiple physical-chemical bonds between the tea residues and the polylactic acid / polybutylene succinate matrix. The interfacial bonding strength is increased by 38%, so that a breaking strength of ≥280N ​​can still be obtained at a high filling ratio, and there is no obvious chipping after 30 household washings. This is a performance breakthrough that is significantly better than the interfacial delamination and mechanical degradation phenomena of the traditional direct physical blending method.

[0054] During the fiber preparation process, the present invention effectively retains the 2-20nm mesoporous structure of tea residue by strictly controlling the parameters of airflow milling, melt blending, spinning, drawing and heat setting processes, and forms a capillary channel network in the core-sheath composite fiber. The final specific surface area of ​​the fabric reaches 20-30m 2 g -1 The water vapor permeability is increased by 31.5%, and the moisture absorption and drying time of the fabric is shortened by 27% compared with pure polyester fabric, which significantly improves the wearing comfort of the finished product in high temperature and high humidity climates. The combination of porous structure and fiber graded stress sharing mechanism breaks through the limitations of existing green fibers in terms of moisture regulation and body feel enhancement.

[0055] The present invention uses the strategy of retaining natural tea polyphenols in the whole process chain and fixing them in the fiber to evenly distribute tea polyphenols and lignin bioactive ingredients on the fiber surface and inside, with a natural antibacterial rate of more than 99% against Escherichia coli and Staphylococcus aureus. In addition, the controllable degradation sequence design of the PBS-PEG-PMG block elastomer sheath layer is used to make the fabric degrade ≥90% within 6 months in a composting environment, and CO 25 The release reaches its peak ahead of time, which is significantly better than the result of existing biodegradable fibers that degrade less than 80% in 6 to 12 months, effectively solving the potential problems of migration, non-degradability and ecological safety of traditional antimicrobial agents. DETAILED DESCRIPTION

[0056] The present invention will now be described in further detail.

[0057] A mesoporous biodegradable composite fiber cloth containing tea residues, comprising a functional plain fabric woven from core-sheath structured composite fibers, wherein the core-sheath structured composite fibers are composed of a core layer and a sheath layer, and the content of each component by total mass is:

[0058] The core layer comprises 28.0-30.4 wt% of tea residue particles with natural mesoporous structure, 32.2-36.4 wt% of polylactic acid, 13.2-19.8 wt% of polybutylene succinate, and 0.6-0.8 wt% of a maleic anhydride grafted polylactic acid compatibilizer.

[0059] The sheath layer comprises 10-12 wt% of polypropylene succinate, 4-6 wt% of polyethylene glycol, and 2-3 wt% of polymaleic anhydride;

[0060] The core layer and the sheath layer form a continuous interface through melt co-extrusion process, and the molar mass of the sheath elastomer structure is 6.2×10 4 ~8.5×10 4 g / mol, the whole fiber has a mesopore size distribution of 2-20 nm and a specific surface area of ​​20-30 m 2 g -1 Multi-level channel network, breaking strength ≥ 280N.

[0061] A method for preparing a mesoporous biodegradable composite fiber cloth containing tea residues comprises the following steps:

[0062] S1. Wash the tea leaves with clean water at room temperature until the conductivity of the extract is no higher than 200μScm -1 , and then freeze-dried at -40 to -35°C and a vacuum degree of 20 to 22 Pa for 12 to 14 hours to obtain dry tea residues with a natural mesoporous structure;

[0063] S2. Dry tea residue at a shear rate of ≤800s -1The tea residue is ground into a particle size of 40 μm to 100 μm in a jet mill to obtain tea residue particles with a mesoporous structure;

[0064] S3. The tea residue particles were kept in a mesoporous structure and the maleic anhydride grafted polylactic acid compatibilizer was dispersed in ethyl lactic acid at a mass ratio of 98:2 to 98.2:1.8 at 60 to 62 ° C and stirred at 300 to 310 rpm for 30 to 35 min to form a compatibility layer on the surface of the tea residue particles to obtain compatible tea residue particles.

[0065] S4. The compatibilized tea residue particles 35-38 wt% and polylactic acid / polybutylene succinate blend matrix 62-65 wt% were added together to melt blend in a twin-screw extruder at a temperature of 175 ℃ ~ 185 ℃, a screw speed of 150-160 rpm, and a residence time of 2.5-3 min to obtain a tea residue blend masterbatch maintaining a mesoporous structure;

[0066] S5. The tea residue blended masterbatch with a mesoporous structure was dried at 80-82°C for 4-4.5 hours as the core material, and then mixed with 20 wt% of polypropylene succinate-polyethylene glycol-polymaleic anhydride elastomer as the sheath material. The mixture was melt-spinned at a temperature of 200-205°C and a draw ratio of 3.5-3.6, and then cooled in a water bath at 20-22°C to obtain tea residue core-sheath filaments with a mesoporous structure.

[0067] S6. The tea residue core-sheath filaments, which retained a mesoporous structure, were subjected to a primary stretching at 60-65°C and a secondary stretching at 90-96°C, with a total stretching ratio of 1.8. The filaments were then heat-set at 120-122°C for 30 seconds to solidify the mesoporous-capillary channel network, yielding functional fiber filaments.

[0068] S7. Use functional fiber filaments as warp yarns (280-300 strands / 10cm) and weft yarns (240-260 strands / 10cm) to weave plain grey fabric, with weaving tension controlled at 35 cNtex. -1 ;

[0069] S8. The plain grey fabric was surface activated with 40W low-temperature plasma for 2 minutes, then dyed in a natural theabrownin dye solution at 70-75°C for 20 minutes with a wet pick-up rate of 85-86%. The fabric was then dried with hot air at 90-92°C for 5-6 minutes to obtain a biodegradable and environmentally friendly fabric with climate adaptability.

[0070] In this embodiment, step S1 specifically includes:

[0071] S11: The tea residue is sequentially soaked and washed three times at room temperature with deionized water, each soaking volume ratio is 1:10, the washing time is 20-30 minutes, and the stirring speed is 250-300 rpm, until the conductivity of the obtained extract is no higher than 200 μScm -1 The obtained tea residue was filtered through a 0.2 mm filter and collected;

[0072] S12: spreading the washed tea residues on a corrosion-resistant metal plate, placing the plate in a freeze-drying apparatus, and freeze-drying the plate at a temperature of -40 to -35°C and a vacuum of 20 to 22 Pa for 12 to 14 hours, until the moisture content of the tea residues is less than 2%, thereby obtaining a dry tea residue raw material with a natural mesoporous structure.

[0073] The main components of S13 dried tea residue are cellulose, lignin and residual tea polyphenols, with the mass fractions of each component being 38-48% for cellulose, 19-24% for lignin and 5-8% for tea polyphenols.

[0074] In this embodiment, step S2 specifically includes:

[0075] S21 will maintain the natural mesoporous structure of dry tea residue raw materials in a relative humidity not higher than 30%, temperature 25 ~ 28 ℃ dry environment pre-stored 2 ~ 3h, to ensure that the moisture content is stable below 2%;

[0076] S22. Use feed inlet pressure of 0.6-0.8MPa and shear rate ≤800s -1 The dry tea residues are ground by a jet mill. The speed of the classifying wheel of the jet mill is set at 2800-3200 rpm. The final particle size distribution of the tea residues is controlled to be between 40 μm and 100 μm, and tea residue particles with a natural mesoporous structure are obtained.

[0077] S23. The tea residue particles maintain a natural mesoporous structure, with a pore size range of 2 to 20 nm and a mesopore ratio of not less than 85% of the total pore structure, and a specific surface area of ​​20 to 30 m 2 g -1 , particle size distribution D 50 The value is 68~72μm.

[0078] In this embodiment, step S3 specifically includes:

[0079] S31 take tea residue particles to maintain the natural mesoporous structure and maleic anhydride grafted polylactic acid compatibilizer, according to the mass ratio of 98:2 ~ 98.2:1.8 were weighed;

[0080] S32. The tea residue particles were mixed with a maleic anhydride grafted polylactic acid compatibilizer and then slowly added to an ethyl lactic acid solution at a constant temperature of 60 to 62 ° C. The stirring speed was controlled at 300 to 310 rpm and the stirring time was continuous for 30 to 35 min, so that the maleic anhydride grafted polylactic acid was uniformly adsorbed and coated on the surface of the tea residue particles to form an interfacial compatibility layer;

[0081] S33. The tea residue particles after compatibilization treatment were vacuum filtered through 0.45 μm and dried in a vacuum drying oven at 45-50°C for 4-5 hours. The resulting product had a polylactic acid-maleic anhydride coating layer on its surface.

[0082] In this embodiment, step S4 specifically includes:

[0083] S41. 35 to 38 wt% of tea residue particles having a polylactic acid - maleic anhydride coating layer are uniformly mixed with 62 to 65 wt% of a biodegradable polyester blend matrix, wherein the biodegradable polyester blend matrix is ​​pre-blended with polylactic acid and polybutylene succinate in a mass ratio of 65:35 to 70:30;

[0084] S42. The mixture was continuously fed into a twin-screw extruder having a screw diameter of 35 to 40 mm and an aspect ratio of 32:1, the melt temperature was set to 175 to 185 ° C, the screw speed was 150 to 160 rpm, the material residence time was 2.5 to 3 min, and melt blending was performed under a nitrogen atmosphere;

[0085] S43. During the blending process, the extrusion shear rate was controlled to be 80-120s -1 , so that the tea residue particles maintain their natural mesoporous structure, while the interface coating layer undergoes segment embedding and compounding with the polyester matrix under the action of heat, forming a tea residue modified blend melt with a mesoporous structure and a thermally stable interface;

[0086] S44. The obtained tea residue modified blend melt was treated by water cooling granulation, with a shear frequency of 30 to 40 cut s -1 The particle size is controlled between 2 and 3 mm to obtain a tea residue blending masterbatch with a mesoporous structure.

[0087] In this embodiment, step S5 specifically includes:

[0088] S51. The tea residue blended masterbatch with a mesoporous structure is placed in a hot air drying oven with a set temperature of 80-82°C and an air flow velocity of 0.3-0.4 m / s for 4-4.5 h until no visible water vapor condenses on the surface of the masterbatch to obtain a dry core spinning material;

[0089] S52. Take the dried core spinning material as the core raw material and feed it together with the sheath raw material. The sheath raw material is a polypropylene succinate - polyethylene glycol - polymaleic anhydride elastomer accounting for 20 wt% by mass;

[0090] S53. The core layer raw material and the sheath layer raw material are fed into the core-sheath composite melt spinning system, and the core layer heating zone temperature is set to 200-203 ° C, the sheath layer heating zone temperature is 203-205 ° C, the main pump flow rate ratio is core layer: sheath layer = 4:1, the spinneret aperture is 0.4 mm, and the extrusion pressure is 12-15 MPa;

[0091] S54. After the melt is extruded through the spinneret assembly, it enters a water bath at 20-22°C for cooling and solidification, and then is directional stretched by a stretching roller group. The stretching ratio is set to 3.5-3.6, and the total stretching speed is 220-240 m / min to obtain tea residue core-sheath filaments with a mesoporous structure. The filament core layer is a tea residue polyester composite phase, and the sheath layer is a PBS-polyethylene glycol-PMG elastomer phase. The overall structure maintains the same mesoporous specific surface area characteristics as step S23 in claim 3.

[0092] In this embodiment, the preparation of the polypropylene succinate-polyethylene glycol-polymaleic anhydride elastomer includes the following steps:

[0093] Succinic acid and 1,3-propylene glycol are added to a reactor in a molar ratio of 1:1.1, 0.3-0.5 wt% of tetrabutyl titanate is added as a catalyst, and an esterification reaction is carried out at 180-190° C. for 3-4 hours. The water generated by the reaction is recovered to obtain a polypropylene succinate prepolymer;

[0094] The poly(propylene succinate) prepolymer is cooled to 160-170° C., polyethylene glycol with an average molecular weight of 2000-4000 is added, and the added weight proportion of polyethylene glycol is 20-30 wt%. The polycondensation reaction is carried out under nitrogen protection for 2-3 hours to obtain a PBS-polyethylene glycol block prepolymer.

[0095] A 1-3 wt% acetone solution of maleic anhydride is added dropwise to the PBS-polyethylene glycol block prepolymer and the reaction is continued at 100-120°C for 2 hours to allow the epoxy groups of the maleic anhydride to graft onto the hydroxyl groups of the polyethylene glycol, forming a block elastomer molecular chain structure with active side groups.

[0096] The block elastomer molecular chain structure with active side groups was precipitated with ethanol and vacuum dried for 12 h to obtain poly(propylene succinate)-poly(ethylene glycol)-poly(maleic anhydride) elastomer with a molar mass of 6.2×10 4 ~8.5×10 4 g / mol, used as sheath material.

[0097] In this embodiment, step S6 specifically includes:

[0098] S61. The tea residue core-sheath filaments with a mesoporous structure are fed into a drawing system and drawn once in a hot roller set at a temperature of 60 to 65°C. The drawing speed is set to 80 to 100 m / min and the draw ratio is controlled to 1.3 to 1.4 times to eliminate lattice defects in the nascent fibers and preliminarily orient the molecular segments.

[0099] S62. The tea residue core-sheath filaments after primary drawing are continuously fed into a second set of heated rollers at a temperature of 90-96°C for secondary drawing. The drawing speed is set at 180-200 m / min, and the draw ratio is controlled at 1.3-1.4 times to align the stress directions of the core and sheath layers and form a stable mesoporous-capillary network structure.

[0100] S63. The tea residue core-sheath filaments, after secondary drawing, were heat-set in a heat-setting apparatus at 120-122°C for 30 seconds to stabilize the polylactic acid / polybutylene succinate blend and the PBS-polyethylene glycol-PMG elastomer under thermal-tensile stress.

[0101] S64. After heat setting, the filaments are cooled to room temperature and relaxed and wound up. The pore size distribution in the core layer of the obtained fiber filaments is maintained in the range of 2 to 20 nm, and the specific surface area is maintained in the range of 20 to 30 m 2 g -1 , fiber breaking strength ≥280N.

[0102] Example 1: Sportswear, a representative application for the fabrics of the present invention, has stringent performance requirements. During exercise, the human body sweats profusely, requiring fabrics with excellent moisture absorption, breathability, and quick-drying properties to quickly direct sweat away from the skin surface and evaporate it, keeping the wearer dry and comfortable. Furthermore, sportswear is often exposed to warm and humid environments, which can easily breed bacteria and cause odor or skin infections. Therefore, the fabrics must possess antibacterial and odor-resistant properties. Common evaluation metrics include inhibition rates against Staphylococcus aureus and Escherichia coli. Sportswear is frequently washed, placing high demands on fabric strength and durability, including initial breaking strength and strength retention after multiple washes. Traditional sportswear often uses synthetic fibers such as polyester, which, despite their strength, are difficult to degrade, creating an environmental burden. In contrast, the present invention utilizes polylactic acid-based biodegradable fibers combined with natural tea residue as a functional filler, imparting biodegradability and environmental friendliness. While meeting mechanical performance requirements, the fabric can be decomposed in a composting environment at the end of its life, significantly reducing environmental pollution. Therefore, the selection of sportswear scenes can fully reflect the comprehensive technical advantages of the fabric of the present invention in terms of moisture absorption and quick drying, antibacterial and deodorizing, washability and durability, and ecological degradation.

[0103] Experimental Background: This Example 1 is based on a pilot production run in a textile materials laboratory in 2024. The raw materials used were tea residue from green tea production at a tea factory and commercial-grade polylactic acid resin pellets. The entire process, from tea residue pretreatment to fiber spinning, weaving, and finishing, is described, and the process parameters and ratios are listed.

[0104] Tea residue raw material processing: Tea residue generated during the processing of fresh green tea leaves (i.e., the residue after brewing or extracting tea leaves) is selected as a functional filler. The tea residue is first rinsed with clean water to remove dust and water-soluble impurities, and then pre-dried in a 60°C forced air drying oven for 4 hours to a moisture content of less than 5%. Low-temperature drying helps retain active substances such as tea polyphenols remaining in the tea residue and avoids the decomposition of active ingredients caused by high temperatures. The dried tea residue is in the form of dark brown flakes, which are then crushed and sieved using a grinder to obtain tea residue micropowder with an average particle size of approximately 50 microns (passing a 100-mesh sieve). Finer grinding is conducive to improving the uniformity of filler dispersion in the polymer and laying the foundation for the subsequent provision of a "mesoporous" structure - tea fibers themselves contain a porous plant cell wall structure. After refinement, the specific surface area increases, which helps to form a micron-level pore system.

[0105] Compatibility modification treatment: Since tea dregs powder is a hydrophilic cellulose / polyphenol substance, its direct compatibility with the hydrophobic polylactic acid matrix is ​​poor, so surface compatibility modification is required. The prepared tea dregs micropowder is mixed with a titanate coupling agent at a weight ratio of 100:3 (i.e., about 3 parts of coupling agent are added for every 100 parts of tea powder). The specific method is as follows: Take an appropriate amount of triisostearate isopropyl titanate coupling agent and dissolve it in anhydrous ethanol to prepare a 2% solution. After spraying a small amount of distilled water evenly to moisten the tea dregs powder, add the coupling agent solution and stir to ensure that all tea powder surfaces are in contact with the coupling agent. Heat and stir at 80°C to evaporate the ethanol, and continue to dry at a constant temperature for 1 hour to form a monomolecular coating of the coupling agent on the surface of the tea dregs particles. After treatment with the coupling agent, the surface hydrophobicity of the tea dregs powder increases, which can better combine with polylactic acid and prevent obvious phase separation at the fiber interface. The amide / ester groups in the coupling agent also react with the phenolic hydroxyl groups in tea polyphenols, capping the end portions to dissolve any lost active ingredients and improving subsequent antimicrobial durability. The modified tea dregs powder is loose and non-agglomerated, with a slightly lighter color, and is ready for use.

[0106] Melt blending and granulation: The modified tea dregs powder described above is mixed with polylactic acid (PLA) resin in a mass ratio of 5:95 (5% tea powder, 95% PLA, corresponding to the preferred range in the claims). Prior to blending, the PLA resin is dried in a drying oven at 80°C for at least 8 hours, reducing its moisture content to <0.1%, to prevent hydrolysis and molecular weight degradation during melting. The PLA pellets and tea dregs powder are then pre-mixed in a high-speed mixer for 5 minutes to obtain a uniform mixture. Melt blending and extrusion granulation are performed using a parallel twin-screw extruder: The mixture is added through the feed port, and the extruder temperature zones are set to 150°C / 160°C / 170°C / 170°C / 165°C (gradually increasing from the feed zone to the die head, a temperature range suitable for PLA processing). The screw speed is set to 100 rpm, with moderate shear to prevent excessive shearing and degradation of the tea polyphenols. A φ3mm aperture die was fitted at the die head to extrude thin strips, which were then water-cooled and pelletized to produce light brown PLA / tea residue composite plastic chips. A faint tea aroma was detected during extrusion, indicating that some of the tea aroma components in the tea residue were released upon heating. The resulting pellets exhibited a smooth, rounded surface with no noticeable agglomeration, demonstrating that the tea residue was well dispersed within the PLA matrix. The tea residue content in the chips was measured to be 5.0 wt%, close to the target formulation value, demonstrating that the coupling modification effectively prevented extrusion separation.

[0107] Core-sheath composite spinning: The above-mentioned PLA / tea residue composite slices are used for spinning to prepare composite functional filaments. The present invention adopts a core-sheath type two-component spinning process, with the core layer being a PLA composite containing tea residue and the sheath layer being pure PLA, to ensure spinning stability and fiber surface smoothness. The experiment uses a laboratory-scale two-component spinning machine (equipped with two extrusion metering pumps and a composite spinneret). PLA / tea residue slices are added to the first hopper, and pure PLA slices are added to the second hopper, and are melted in their respective single-screw extruders. The two melts merge at the spinneret to form a core-sheath composite flow. The spinning temperature parameters are set as follows: core component extruder temperature 165°C, sheath component extruder temperature 160°C, spinneret assembly temperature 170°C, and the metering pump speed is adjusted according to the fiber linear density requirements. The core-sheath volume ratio is controlled to 70:30, that is, the core layer accounts for approximately 70% of the fiber cross-sectional area, and the sheath layer accounts for approximately 30%. A composite spinneret with a diameter of 0.3 mm is used, with a total of 24 holes for spinning. Each hole spins a core-sheath composite monofilament, and the 24 monofilaments are gathered into a strand for traction and winding to form a filament bundle. The spinning speed (winding speed) is set to 800 m / min, and air is blown to cool and form: room temperature cooling air is blown in 10 cm below the spinneret at a wind speed of 0.5 m / s to ensure that the fiber is quickly solidified and fixed without adhesion. The spun primary fiber (unstretched yarn) is light brown transparent filament with a linear density of approximately 5.5 dtex / monofilament. The tea residue gives the fiber a natural beige-brown hue, and no subsequent dyeing is required. The fiber surface is smooth and continuous, indicating that the sheath layer PLA effectively covers the core layer containing filler.

[0108] Drawing and Setting: The spun fiber filaments were placed in a 50°C constant-temperature drying oven for 12 hours to eliminate internal stress. Afterwards, they were hot-drawn to enhance strength. A two-stage drawing process was employed: the first stage was drawing in a hot water bath at 70°C (slightly above the PLA glass transition temperature of approximately 60-65°C) with a draw ratio of 3.0; the second stage was drawing on a hot roller at a surface temperature of 110°C with a draw ratio of 1.3. The total draw ratio was approximately 3.0 × 1.3 = 3.9. The drawing process was controlled to maintain a uniform speed to prevent fiber breakage. After drawing, the fiber diameter decreased from approximately 30 μm in the undrawn state to approximately 15 μm, significantly improving the degree of crystal orientation. Heat-setting treatment was then performed: the drawn fibers were baked in a 120°C hot air oven for 5 minutes without tension, then lightly tensioned and set at 120°C for 2 minutes. This step relieves internal stress in the fibers and induces the formation of a more stable crystalline structure in the PLA matrix. The resulting composite filaments exhibit excellent dimensional stability and heat resistance (heat shrinkage <3%). The tensile strength of the single filament reached 4.2 cN / dtex, approximately 20% higher than that of pure PLA fibers without tea residue (approximately 3.5 cN / dtex). This demonstrates that a small amount of tea residue filling and tensile orientation enhances fiber strength. This is likely due to the tea residue particles acting as heterogeneous nucleating agents, increasing the crystallinity of the PLA, while also providing good interface bonding between the filler and the matrix, which partially bears the load.

[0109] Fabric weaving: The obtained PLA / tea residue core-sheath composite filaments are used to weave fabrics. This embodiment selects woven plain cloth for demonstration. First, the filaments are twisted to form weaving yarns: 24 strands of filaments after stretching and setting are bundled and twisted in the S direction with a twist of 300 twists / m to obtain a composite yarn with a linear density of about 110tex (equivalent to a filament of about 100D / 24f). For comparative experiments, pure PLA filaments are also made into control yarns using the same process. A small sample loom was selected, and the warp and weft yarns were woven into plain cloth using the above-mentioned composite yarns. The warp density was about 180 strands / 10cm, the weft density was about 170 strands / 10cm, and the fabric weight was about 130g / m 2 The yarn ran smoothly during weaving without any breakage, indicating that the yarn was strong enough to meet weaving requirements. The woven fabric had a light brown color, was soft to the touch, and had a slight tea aroma.

[0110] Fabric Post-Processing: The woven PLA / tea slag plain weave fabric was subjected to conventional textile finishing. First, it was scoured and washed under mild conditions: the fabric was placed in 40°C warm water with a neutral detergent for 30 minutes, gently agitated, and washed to remove impurities such as spinning oil. The fabric was then rinsed with deionized water. Given that the fabric of this invention already has a natural brown color and its antimicrobial properties are internal, dyeing and antimicrobial finishing are unnecessary, simplifying the post-processing process. The washed fabric was dried at 80°C for 5 minutes to smooth the surface and set the width. The resulting finished fabric was a light brown PLA / tea slag mesoporous biodegradable composite fiber fabric. Microscopic examination of the finished fiber cross-section revealed a uniform distribution of dark tea slag particles within the core layer, with micropores forming around some of the particles. This mesoporous structure enhances the fabric's moisture absorption and breathability, accelerating biodegradation. The finished fabric exhibited uniform width and no significant defects. Before performance testing, the fabric was conditioned for 24 hours under standard atmospheric conditions (20±2°C, 65% relative humidity).

[0111] We conducted multiple rounds of performance testing comparing the fabric of the present invention (PLA / tea residue composite fiber plain weave) and a control group of conventional pure PLA fiber fabric, including antibacterial properties, breaking strength and wash durability, biodegradability, and moisture absorption and quick-drying. Each test was conducted in accordance with relevant textile industry standards and specifications to verify the feasibility and technical advantages of this invention in the field of sports textiles. The test data is as follows:

[0112] Antibacterial Performance: The antibacterial effect of the fabric was evaluated using a modified AATCC 100 method. Fabric samples were cut into 50×50 mm specimens and inoculated under sterile conditions with suspensions of Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 8739), each at an initial concentration of approximately 10⁵ CFU / mL. After incubation at 37°C for 24 hours, the number of surviving colonies was determined using the elution culture enumeration method. The inhibition rate was calculated as (number of colonies in the control group - number of colonies in the sample group) / number of colonies in the control group × 100%. Results: The PLA / tea waste composite fabric demonstrated an inhibition rate of 92% against Staphylococcus aureus and approximately 89% against Escherichia coli, demonstrating significant broad-spectrum antibacterial activity. Pure PLA fabric showed virtually no antibacterial activity against these bacteria (inhibition rate less than 5%). This demonstrates that the natural antibacterial components of tea waste, such as tea polyphenols, are uniformly embedded in the fiber and exert their sustained effects, achieving intrinsic antibacterial activity. We also investigated the durability of the fabric's antibacterial properties: We subjected both fabrics to 10 washes in a standard household washing machine (40°C water temperature, neutral detergent, 15 minutes per wash, rinse with clean water), and then measured their antibacterial efficacy. The fabric of the present invention maintained an inhibition rate against Staphylococcus aureus of over 80% after 10 washes, showing only a slight decrease. In contrast, pure PLA fabric, which lacks antibacterial properties, showed no difference before and after washes. This demonstrates that the fabric of the present invention exhibits durable antibacterial properties, making it suitable for sportswear that requires frequent washing.

[0113] Breaking Strength: Fabric breaking strength was tested using the strip method according to GB / T 3923.1. Fabric samples were cut with a width of 50 mm and a gauge length of 200 mm in both the warp and weft directions and stretched on an electronic tensile testing machine at a speed of 100 mm / min until breaking. The maximum force required to break was recorded. Tests showed that the PLA / tea residue composite fabric of the present invention had an average breaking strength of 310 N in the warp direction and 305 N in the weft direction. Pure PLA fabric prepared using the same process had breaking strengths of 260 N and 255 N in the warp and weft directions, respectively. The addition of 5% tea residue and core-sheath spinning increased the breaking strength of the fabric by approximately 20%. This improvement is attributed to the reinforcement of tea residue particles and the improved fiber orientation, which increases the load-bearing capacity of the fibers and yarns. Furthermore, the composite fiber fabric exhibited a high elongation (approximately 30%) at break, rather than a brittle fracture, and had a slightly softer feel, contributing to the comfort of sportswear.

[0114] Strength Retention After Washing: To assess fabric durability, we tested the strength of samples after repeated washings. The two fabrics were machine washed 20 times at 40°C using a home washing method. After drying and re-humidifying each time, the breaking strength test was repeated. The results showed that the fabric of the present invention retained 92% of its breaking strength in the warp direction (a slight decrease from 310N to 285N) and 90% in the weft direction after 20 washes. In contrast, the pure PLA fabric retained only approximately 75% of its strength in the warp direction (from 260N to 195N) and approximately 78% in the weft direction after the same number of washes. This comparison shows that the pure PLA fabric exhibits a significant decrease in strength after repeated washings, likely due to shortening of the PLA polymer chains by hydrolysis and fiber damage caused by the mechanical effects of washing. The composite fiber fabric of the present invention, on the other hand, maintained essentially stable strength, demonstrating that the presence of tea residue filler enhances the fiber's hydrolytic stability and resistance to repeated mechanical stress, enabling it to withstand frequent washings and meet the durability requirements of sportswear.

[0115] Biodegradation performance: According to the ISO 20200 compost degradation test method, the degradability of the two fabrics was examined. The cut fabric samples (size 5cm×5cm) were buried in a simulated industrial composting environment (temperature 58°C, relative humidity ≈95%, mixed with organic media such as activated sludge and leaves), and the residual mass was measured after cleaning and drying at irregular intervals. The experimental time span was set to 12 weeks (84 days). The results showed that after 1 month (30 days) in the composting environment, the PLA / tea residue composite fabric sample showed signs of biodegradation visible to the naked eye, with a mass residue of about 82% (degraded 18%); at the same time, the pure PLA fabric sample was basically intact, with a mass residue of about 95%.

[0116] Example 2: During exercise, the human body sweats a lot, and clothing fabrics need to have good moisture absorption, breathability and quick-drying properties to promptly guide sweat away from the skin surface and evaporate it quickly to keep the wearer dry and comfortable. In addition, sportswear is often in a warm and humid environment, which is prone to breeding bacteria, causing odor or skin infection. Therefore, the fabrics need to have antibacterial and deodorizing functions. Common evaluation indicators include the inhibition rate against Staphylococcus aureus and Escherichia coli. Sportswear needs to be washed frequently, so the strength and durability of the fabric are very high, including indicators such as initial breaking strength and strength retention after multiple washings must meet the standards. Traditional sportswear mostly uses synthetic fibers such as polyester, which have high strength but are not easy to degrade, causing an environmental burden. In contrast, the present invention uses polylactic acid (PLA)-based degradable fibers, combined with natural tea residue functional fillers, to give the material biodegradability and environmental protection characteristics. While meeting the mechanical properties, the fabric can be decomposed in a composting environment after the end of its service life, greatly reducing environmental pollution. Therefore, the selection of sportswear scenes can fully reflect the comprehensive technical advantages of the fabric of the present invention in terms of moisture absorption and quick drying, antibacterial and deodorizing, washability and durability, and ecological degradation.

[0117] Example 2 is based on a small trial production in a textile material laboratory.

[0118] Tea residue raw material processing: Tea residue generated during the processing of fresh green tea leaves (i.e., the residue after brewing or extracting tea leaves) is selected as a functional filler. The tea residue is first rinsed with clean water to remove dust and water-soluble impurities, and then pre-dried in a 60°C forced air drying oven for 4 hours to a moisture content of less than 5%. Low-temperature drying helps retain active substances such as tea polyphenols remaining in the tea residue and avoids the decomposition of active ingredients caused by high temperatures. The dried tea residue is in the form of dark brown flakes, which are then crushed and sieved using a grinder to obtain tea residue micropowder with an average particle size of approximately 50 microns (passing a 100-mesh sieve). Finer grinding is conducive to improving the uniformity of filler dispersion in the polymer and laying the foundation for the subsequent provision of a "mesoporous" structure - tea fibers themselves contain a porous plant cell wall structure. After refinement, the specific surface area increases, which helps to form a micron-level pore system.

[0119] Compatibility modification treatment: Since tea dregs powder is a hydrophilic cellulose / polyphenol substance, its direct compatibility with the hydrophobic polylactic acid matrix is ​​poor, so surface compatibility modification is required. The prepared tea dregs micropowder is mixed with a titanate coupling agent at a weight ratio of 100:3 (i.e., about 3 parts of coupling agent are added for every 100 parts of tea powder). The specific method is as follows: Take an appropriate amount of triisostearate isopropyl titanate coupling agent and dissolve it in anhydrous ethanol to prepare a 2% solution. After spraying a small amount of distilled water evenly to moisten the tea dregs powder, add the coupling agent solution and stir to ensure that all tea powder surfaces are in contact with the coupling agent. Heat and stir at 80°C to evaporate the ethanol, and continue to dry at a constant temperature for 1 hour to form a monomolecular coating of the coupling agent on the surface of the tea dregs particles. After treatment with the coupling agent, the surface hydrophobicity of the tea dregs powder increases, which can better combine with polylactic acid and prevent obvious phase separation at the fiber interface. At the same time, the ester and other functional groups in the coupling agent can also react with the phenolic hydroxyl groups in tea polyphenols, blocking some of the active ingredients that are easily dissolved and lost, thereby improving the subsequent antibacterial durability. The modified tea residue powder is loose and non-agglomerated, with a slightly lighter color, and is ready for use.

[0120] Melt blending and granulation: The modified tea dregs powder described above is mixed with polylactic acid (PLA) resin in a mass ratio of 5:95 (5% tea powder, 95% PLA, corresponding to the preferred range in the claims). Prior to blending, the PLA resin is dried in a drying oven at 80°C for at least 8 hours, reducing its moisture content to <0.1%, to prevent hydrolysis and molecular weight degradation during melting. The PLA pellets and tea dregs powder are then pre-mixed in a high-speed mixer for 5 minutes to obtain a uniform mixture. Melt blending and extrusion granulation are performed using a parallel twin-screw extruder: The mixture is added through the feed port, and the extruder temperature zones are set to 150°C / 160°C / 170°C / 170°C / 165°C (gradually increasing from the feed zone to the die head, a temperature range suitable for PLA processing). The screw speed is set to 100 rpm, with moderate shear to prevent excessive shearing and degradation of the tea polyphenols. A φ3mm aperture die was installed at the die head to extrude thin strips, which were then water-cooled and pelletized to produce light brown PLA / tea residue composite plastic chips. A faint tea aroma was detected during extrusion, indicating that some of the aroma components in the tea residue were released upon heating. The resulting pellets exhibited a smooth, rounded surface with no noticeable agglomeration, demonstrating that the tea residue was well dispersed within the PLA matrix. The tea residue content in the chips was measured to be 5.0 wt%, close to the target formulation value, demonstrating that the coupling modification effectively prevented extrusion separation.

[0121] Core-sheath composite spinning: The above-mentioned PLA / tea residue composite slices are used for spinning to prepare composite functional filaments. The present invention adopts a core-sheath type two-component spinning process, the core layer is a PLA composite containing tea residue, and the sheath layer is pure PLA, to ensure spinning stability and fiber surface smoothness. The experiment uses a laboratory two-component spinning machine (equipped with two extrusion metering pumps and a composite spinneret). PLA / tea residue slices are added to the first hopper, and pure PLA slices are added to the second hopper. They are melted in their respective single-screw extruders, and the two melts merge at the spinneret to form a core-sheath composite flow. The spinning temperature parameters are set as follows: core component extruder temperature 165°C, sheath component extruder temperature 160°C, spinneret assembly temperature 170°C, and the metering pump speed is adjusted according to the fiber linear density requirements. The core-sheath volume ratio is controlled to 70:30, that is, the core layer accounts for about 70% of the fiber cross-sectional area, and the sheath layer accounts for about 30%. A composite spinneret with a diameter of 0.3 mm is used, with a total of 24 holes for spinning. Each hole spins a core-sheath composite monofilament, and the 24 monofilaments are gathered into a strand that is pulled and wound into a filament bundle. The spinning speed (winding speed) is set to 800 m / min, and air is blown to cool and form: room temperature cooling air is blown in 10 cm below the spinneret at a speed of 0.5 m / s to ensure that the fiber is quickly solidified and fixed without adhesion. The spun primary fiber (unstretched yarn) is light brown transparent filament with a linear density of approximately 5.5 dtex / monofilament. The tea residue gives the fiber a natural beige hue, and no subsequent dyeing is required. The fiber surface is smooth and continuous, indicating that the sheath layer PLA effectively covers the core layer containing filler.

[0122] Drawing and Setting: The spun fiber filaments were placed in a 50°C constant-temperature drying oven for 12 hours to eliminate internal stress. Afterwards, they were hot-drawn to enhance strength. A two-stage drawing process was employed: the first stage was drawing in a hot water bath at 70°C (slightly above the PLA glass transition temperature of approximately 60-65°C) with a draw ratio of 3.0; the second stage was drawing on a hot roller at a surface temperature of 110°C with a draw ratio of 1.3. The total draw ratio was approximately 3.0 × 1.3, which is approximately 3.9. The drawing process was controlled to maintain a uniform speed to prevent fiber breakage. After drawing, the fiber diameter decreased from approximately 30 μm in the undrawn state to approximately 15 μm, significantly improving the degree of crystal orientation. Heat-setting treatment was then performed: the drawn fibers were baked in a 120°C hot air oven for 5 minutes without tension, then lightly tensioned and set at 120°C for 2 minutes. This step relieves internal stress in the fibers and induces a more stable crystalline structure in the PLA matrix. The resulting composite filaments exhibit excellent dimensional stability and heat resistance (heat shrinkage in boiling water <3%). The tensile strength of the single filament was measured to reach 4.2 cN / dtex, approximately 20% higher than that of pure PLA fibers without tea residue (approximately 3.5 cN / dtex), demonstrating that a small amount of tea residue filling and tensile orientation enhances fiber strength. This is likely due to the tea residue particles acting as a heterogeneous nucleating agent, which increases the crystallinity of the PLA. Furthermore, the filler-matrix interface is well bonded, effectively supporting the load under stress.

[0123] Fabric weaving: The obtained PLA / tea residue core-sheath composite filaments are used to weave fabrics. This embodiment selects woven plain cloth for demonstration. First, the filaments are twisted to form weaving yarns: 24 filaments after stretching and setting are bundled and twisted in the S direction with a twist of 300 twists / m to obtain a composite yarn with a linear density of about 110tex (equivalent to a filament of about 100 denier / 24 filaments). For comparative experiments, pure PLA filaments are also made into control yarns using the same process. A small sample loom is selected, and the warp and weft yarns are woven into plain cloth using the above-mentioned composite yarns. The warp density is about 180 yarns / 10cm, the weft density is about 170 yarns / 10cm, and the fabric weight is about 130g / m 2 The yarn ran smoothly during weaving without any breakage, indicating that the yarn was strong enough to meet weaving requirements. The woven fabric had a light brown color, was soft to the touch, and had a slight tea aroma.

[0124] Fabric Post-Processing: The woven PLA / tea slag plain weave fabric undergoes conventional textile finishing. First, it is scour-washed under mild conditions: the fabric is placed in 40°C warm water with a neutral detergent for 30 minutes, gently agitated, and washed to remove residues such as spinning lubricants. The fabric is then rinsed with deionized water. Given that the fabric of this invention already has a natural tea color and its antimicrobial properties are inherent to the fiber itself, dyeing and additional antimicrobial finishing are unnecessary, simplifying the post-processing process. The washed fabric is then dried at 80°C for 5 minutes to smooth the surface and stabilize the width. The resulting finished fabric is a light brown PLA / tea slag mesoporous biodegradable composite fiber fabric. Microscopic examination of the finished fiber cross-section reveals evenly distributed dark tea slag particles within the core layer, with microscopic pores forming around some of the particles. This mesoporous structure improves the fabric's moisture absorption and breathability, and provides microscopic attachment pathways for microbial degradation, accelerating the biodegradation of the material. The finished fabric has uniform width and no obvious defects. It is conditioned for 24 hours under standard atmospheric conditions (temperature 20±2°C, relative humidity 65%) before performance testing.

[0125] We conducted multiple rounds of performance testing comparing the fabric of the present invention (PLA / tea residue composite fiber plain weave) and a control group of conventional pure PLA fiber fabric, including antibacterial properties, breaking strength and wash durability, biodegradability, and moisture absorption and quick-drying properties. Each test was conducted in accordance with relevant textile industry standards and specifications to verify the feasibility and technical advantages of this invention in the field of sports textiles. The test data and results are analyzed below:

[0126] Antibacterial Performance: The antibacterial effect of the fabric was evaluated using a modified AATCC 100 method. Fabric samples were cut into 50×50 mm specimens and inoculated under sterile conditions with suspensions of Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 8739), each at an initial concentration of approximately 10⁵ CFU / mL. After incubation at 37°C for 24 hours, the number of surviving colonies was determined using the elution culture enumeration method. The inhibition rate was calculated as (number of colonies in the control group - number of colonies in the sample group) / number of colonies in the control group × 100%. Results: The PLA / tea waste composite fabric demonstrated an inhibition rate of 92% against Staphylococcus aureus and approximately 89% against Escherichia coli, demonstrating significant broad-spectrum antibacterial activity. Pure PLA fabric showed virtually no antibacterial activity against these bacteria (inhibition rate <5%). This demonstrates that the natural antibacterial components, such as tea polyphenols, found in tea waste, remain active after being embedded in the fiber, achieving long-lasting antibacterial, mildew-resistant, and deodorizing properties. We also examined the durability of the antibacterial properties: We washed both fabrics 10 times in a standard household washing machine (40°C water temperature, neutral detergent, 15 minutes per wash, rinsed with clean water) and then tested their antibacterial efficacy using the aforementioned method. The antibacterial rate of the fabric of the present invention against Staphylococcus aureus remained above 80% after 10 washes, with only a slight decrease. In contrast, pure PLA fabric, which has no antibacterial properties, showed no antibacterial effect before or after washing. This demonstrates that the antibacterial properties of the fabric of the present invention are durable and long-lasting, making it ideal for sportswear that requires frequent cleaning.

[0127] Breaking Strength: Fabric breaking strength was tested using the strip method according to GB / T 3923.1. Fabric samples, 50 mm wide and 200 mm in gauge length, were cut in both the warp and weft directions and stretched on an electronic tensile testing machine at a speed of 100 mm / min until breaking. The maximum force at break was recorded. Tests showed that the PLA / tea residue composite fabric of the present invention had an average breaking strength of 310 N in the warp direction and 300 N in the weft direction. Pure PLA fabric prepared using the same process had breaking strengths of 260 N and 250 N in the warp and weft directions, respectively. The addition of 5% tea residue and core-sheath spinning increased the fabric's breaking strength by approximately 20%. This improvement is attributed to the enhanced strength of the tea residue particles and improved fiber orientation, which increases the load-bearing capacity of the fibers and yarns. Furthermore, the composite fiber fabric exhibited a high elongation at break (approximately 30%, slightly higher than the 25% for pure PLA fabric), preventing sudden brittle fracture during stretching and resulting in a more supple feel, contributing to improved comfort and safety in sportswear.

[0128] Strength Retention After Washing: To assess fabric durability, we tested the strength of samples after multiple washes. The two fabrics were machine washed 20 times at 40°C using home washing methods. After each wash, they were dried and conditioned to a standard breaking strength before measuring their breaking strength. The results showed that the fabric of the present invention retained 92% of its breaking strength in the warp direction (a slight decrease from an initial 310N to 285N), and 90% in the weft direction after 20 washes. In contrast, the pure PLA fabric retained only approximately 75% of its strength in the warp direction (from 260N to 195N), and approximately 78% in the weft direction, after the same number of washes. This comparison shows that the pure PLA fabric exhibits a significant decrease in strength after multiple washes, likely due to degradation of the PLA molecular chains by hydrolysis and fiber damage caused by mechanical friction during washing. The composite fiber fabric of the present invention, on the other hand, maintained essentially stable strength, demonstrating that the presence of tea residue filler enhances the fiber's hydrolytic stability, enabling it to better maintain structural integrity after repeated washings, thus meeting the stringent durability requirements of sportswear.

[0129] Biodegradability: The biodegradability of the two fabrics was investigated according to the ISO 20200 composting test method. Cut fabric samples (5 cm x 5 cm) were placed in a simulated industrial composting environment (temperature 58°C, relative humidity ≈95%, organic medium containing active microorganisms). Samples were removed at various times, washed and dried, and the residual mass was measured over time. The test lasted 12 weeks. Results showed that after 30 days in the composting environment, the PLA / tea residue composite fabric sample showed signs of biodegradation, with approximately 82% of its mass remaining (18% degradation). Under the same conditions, the pure PLA fabric sample retained approximately 95% of its mass, showing virtually no degradation. After 6 weeks (42 days), the composite fabric's residual mass dropped to approximately 65%, while the pure PLA fabric retained approximately 85%. By 12 weeks (84 days), the composite fabric had largely degraded, with less than 10% of its mass remaining (degradation rate >90%). In contrast, the pure PLA fabric still had approximately 50% of its mass remaining, incompletely degraded. This demonstrates that the incorporation of tea waste significantly increases the biodegradation rate of the fiber. Under composting conditions, tea waste components degrade first, forming pores that facilitate microbial attack on the PLA matrix. Furthermore, the plant cellulose and polysaccharides in the tea waste serve as a readily available carbon source for microorganisms, aiding their growth and accelerating the decomposition of the material. These results demonstrate that the fabric of this invention is more biodegradable than traditional PLA fabrics, meeting environmental protection requirements.

[0130] Moisture Absorption and Drying Performance: We evaluated the fabric's moisture absorption and quick-drying properties using moisture absorption and droplet diffusion / evaporation tests. First, the fabric's moisture regain (moisture absorption) was measured under standard atmospheric pressure: samples were equilibrated in a constant temperature and humidity chamber at 20°C and 65% relative humidity for 48 hours and then weighed. The equilibrium moisture regain of the PLA / tea dregs composite fabric was approximately 0.8%, significantly higher than the 0.4% of pure PLA fabric. This indicates that the addition of tea dregs enhances the fiber's ability to absorb ambient moisture, aiding in the absorption of sweat from the skin's surface. A droplet diffusion test was then conducted: equal amounts of distilled water were dripped onto the surfaces of the two fabrics, and the rate of water droplet wetting, spreading, and diffusion on the fabrics was observed. The results showed that the water droplets on the composite fabric were absorbed by the fibers within 5 seconds and quickly spread along the yarn, forming a wet spot. In contrast, the water droplets on the pure PLA fabric remained in the form of raised beads and were not completely absorbed after 30 seconds, sliding slowly along the surface. This phenomenon indicates that the composite fabric is more hydrophilic, enabling faster absorption and diffusion of sweat. Finally, the drying rates of the two fabrics were tested: completely soaked fabric samples were suspended in still air at 25°C and 50% relative humidity, and their moisture content was measured over time. Statistics showed that the composite fabric of the present invention could return to near-dryness (residual moisture content <5%) within 20 minutes, while pure PLA fabric under the same conditions took approximately 28 minutes to reach a similar level of dryness. Overall, the PLA / tea dregs composite fabric, due to its internal mesoporous structure and hydrophilic components, not only moderately absorbs sweat for enhanced wearing comfort, but also rapidly evaporates moisture, achieving true moisture absorption and quick drying, making it ideally suited for the moisture and heat management requirements of sportswear.

[0131] In summary, the full preparation process and performance comparison data from Example 2 demonstrate that the mesoporous, biodegradable composite fiber fabric containing tea residues described herein exhibits significant performance advantages in the field of sports textiles. It combines excellent antibacterial and deodorizing properties, increased breaking strength and wash stability, good moisture wicking properties, and compostability after use. It meets the comprehensive requirements of sportswear for comfort, functionality, and environmental friendliness, and has great potential for widespread application.

[0132] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A mesoporous biodegradable composite fiber cloth containing tea residues, characterized in that: A functional plain fabric woven from core-sheath structure composite fibers, wherein the core-sheath structure composite fibers are composed of a core layer and a sheath layer, and the content of each component by total mass is: The core layer comprises 28.0-30.4 wt% of tea residue particles with natural mesoporous structure, 32.2-36.4 wt% of polylactic acid, 13.2-19.8 wt% of polybutylene succinate, and 0.6-0.8 wt% of a maleic anhydride grafted polylactic acid compatibilizer. The sheath layer comprises 10-12 wt% of polypropylene succinate, 4-6 wt% of polyethylene glycol, and 2-3 wt% of polymaleic anhydride.

2. A method for preparing a mesoporous biodegradable composite fiber cloth containing tea residues, characterized in that: The steps include: S1. Wash the tea leaves with clean water at room temperature until the conductivity of the extract is no higher than 200μScm -1 , and then freeze-dried at -40 to -35°C and a vacuum degree of 20 to 22 Pa for 12 to 14 hours to obtain dry tea residues with a natural mesoporous structure; S2. Dry tea residue at a shear rate of ≤800s -1 The tea residue is ground into a particle size of 40 μm to 100 μm in a jet mill to obtain tea residue particles with a mesoporous structure; S3. The tea residue particles were kept in a mesoporous structure and the maleic anhydride grafted polylactic acid compatibilizer was dispersed in ethyl lactic acid at a mass ratio of 98:2 to 98.2:1.8 at 60 to 62 ° C and stirred at 300 to 310 rpm for 30 to 35 min to form a compatibility layer on the surface of the tea residue particles to obtain compatible tea residue particles. S4. The compatibilized tea residue particles 35-38 wt% and polylactic acid / polybutylene succinate blend matrix 62-65 wt% were added together to melt blend in a twin-screw extruder at a temperature of 175 ℃ ~ 185 ℃, a screw speed of 150-160 rpm, and a residence time of 2.5-3 min to obtain a tea residue blend masterbatch maintaining a mesoporous structure; S5. The tea residue blended masterbatch with a mesoporous structure was dried at 80-82°C for 4-4.5 hours as the core material, and then mixed with 20 wt% of polypropylene succinate-polyethylene glycol-polymaleic anhydride elastomer as the sheath material. The mixture was melt-spinned at a temperature of 200-205°C and a draw ratio of 3.5-3.6, and then cooled in a water bath at 20-22°C to obtain tea residue core-sheath filaments with a mesoporous structure. S6. The tea residue core-sheath filaments, which retained a mesoporous structure, were subjected to a primary stretching at 60-65°C and a secondary stretching at 90-96°C, with a total stretching ratio of 1.

8. The filaments were then heat-set at 120-122°C for 30 seconds to solidify the mesoporous-capillary channel network, yielding functional fiber filaments. S7. Use functional fiber filaments as warp yarns (280-300 strands / 10cm) and weft yarns (240-260 strands / 10cm) to weave plain grey fabric, with weaving tension controlled at 35 cNtex. -1 ; S8. The plain grey fabric was surface activated with 40W low-temperature plasma for 2 minutes, and then dyed in a natural theabrownin dye solution at 70-75°C for 20 minutes with a wet pick-up rate of 85-86%. The fabric was then dried with hot air at 90-92°C for 5-6 minutes to obtain a biodegradable and environmentally friendly fabric with climate adaptability.

3. The method for preparing a mesoporous biodegradable composite fiber cloth containing tea residues according to claim 2, characterized in that: The S1 step specifically includes: S11: The tea residue is sequentially soaked and washed three times at room temperature with deionized water, each soaking volume ratio is 1:10, the washing time is 20-30 minutes, and the stirring speed is 250-300 rpm, until the conductivity of the obtained extract is no higher than 200 μScm -1 The obtained tea residue was filtered through a 0.2 mm filter and collected; S12: spreading the washed tea residues on a corrosion-resistant metal plate, placing the plate in a freeze-drying apparatus, and freeze-drying the plate at a temperature of -40 to -35°C and a vacuum of 20 to 22 Pa for 12 to 14 hours, until the moisture content of the tea residues is less than 2%, thereby obtaining a dry tea residue raw material with a natural mesoporous structure. The main components of the dried tea residue in S13 are cellulose, lignin and residual tea polyphenols, and the mass fractions of each component are 38-48% of cellulose, 19-24% of lignin and 5-8% of tea polyphenols.

4. The method for preparing a mesoporous biodegradable composite fiber cloth containing tea residues according to claim 1, characterized in that: The S2 step specifically includes: S21 will maintain the natural mesoporous structure of dry tea residue raw materials in a relative humidity not higher than 30%, temperature 25 ~ 28 ℃ dry environment pre-stored 2 ~ 3h, to ensure that the moisture content is stable below 2%; S22. Use feed inlet pressure of 0.6-0.8MPa and shear rate ≤800s -1 The dry tea residues are ground by a jet mill. The speed of the classifying wheel of the jet mill is set at 2800-3200 rpm. The final particle size distribution of the tea residues is controlled to be between 40 μm and 100 μm, and tea residue particles with a natural mesoporous structure are obtained. S23. The tea residue particles maintain a natural mesoporous structure, with a pore size range of 2 to 20 nm and a mesopore ratio of not less than 85% of the total pore structure, and a specific surface area of ​​20 to 30 m 2 g -1 , particle size distribution D 50 The value is 68~72μm.

5. The method for preparing a mesoporous biodegradable composite fiber cloth containing tea residues according to claim 1, characterized in that: The S3 step specifically includes: S31 take tea residue particles to maintain the natural mesoporous structure and maleic anhydride grafted polylactic acid compatibilizer, according to the mass ratio of 98:2 ~ 98.2:1.8 were weighed; S32. The tea residue particles were mixed with a maleic anhydride grafted polylactic acid compatibilizer and then slowly added to an ethyl lactic acid solution at a constant temperature of 60 to 62 ° C. The stirring speed was controlled at 300 to 310 rpm and the stirring time was continuous for 30 to 35 min, so that the maleic anhydride grafted polylactic acid was uniformly adsorbed and coated on the surface of the tea residue particles to form an interfacial compatibility layer; S33. The tea residue particles after compatibilization treatment were vacuum filtered through 0.45 μm and dried in a vacuum drying oven at 45-50°C for 4-5 hours. The resulting product had a polylactic acid-maleic anhydride coating layer on its surface.

6. The method for preparing a mesoporous biodegradable composite fiber cloth containing tea residues according to claim 1, characterized in that: The S4 step specifically includes: S41. 35 to 38 wt% of tea residue particles having a polylactic acid - maleic anhydride coating layer are uniformly mixed with 62 to 65 wt% of a biodegradable polyester blend matrix, wherein the biodegradable polyester blend matrix is ​​pre-blended with polylactic acid and polybutylene succinate in a mass ratio of 65:35 to 70:30; S42. The mixture was continuously fed into a twin-screw extruder having a screw diameter of 35 to 40 mm and an aspect ratio of 32:1, the melt temperature was set to 175 to 185 ° C, the screw speed was 150 to 160 rpm, the material residence time was 2.5 to 3 min, and melt blending was performed under a nitrogen atmosphere; S43. During the blending process, the extrusion shear rate was controlled to be 80-120s -1 , so that the tea residue particles maintain their natural mesoporous structure, while the interface coating layer undergoes segment embedding and compounding with the polyester matrix under the action of heat, forming a tea residue modified blend melt with a mesoporous structure and a thermally stable interface; S44. The obtained tea residue modified blend melt was treated by water cooling granulation, with a shear frequency of 30 to 40 cut s -1 The particle size is controlled between 2 and 3 mm to obtain a tea residue blending masterbatch with a mesoporous structure.

7. The method for preparing a mesoporous biodegradable composite fiber cloth containing tea residues according to claim 1, characterized in that: The S5 step specifically includes: S51. The tea residue blended masterbatch with a mesoporous structure is placed in a hot air drying oven with a set temperature of 80-82°C and an air flow velocity of 0.3-0.4 m / s for 4-4.5 h until no visible water vapor condenses on the surface of the masterbatch to obtain a dry core spinning material; S52. Take the dried core spinning material as the core raw material and feed it together with the sheath raw material. The sheath raw material is a polypropylene succinate - polyethylene glycol - polymaleic anhydride elastomer accounting for 20 wt% by mass; S53. The core layer raw material and the sheath layer raw material are fed into the core-sheath composite melt spinning system, and the core layer heating zone temperature is set to 200-203 ° C, the sheath layer heating zone temperature is 203-205 ° C, the main pump flow rate ratio is core layer: sheath layer = 4:1, the spinneret aperture is 0.4 mm, and the extrusion pressure is 12-15 MPa; S54. After the melt is extruded through the spinneret assembly, it enters a water bath at 20-22°C for cooling and solidification, and then is directional stretched by a stretching roller group. The stretching ratio is set to 3.5-3.6, and the total stretching speed is 220-240 m / min to obtain tea residue core-sheath filaments with a mesoporous structure. The core layer of the filament is a tea residue polyester composite phase, and the sheath layer is a PBS-polyethylene glycol-PMG elastomer phase. The overall structure maintains the same mesoporous specific surface area characteristics as step S23 in claim 3.

8. The method for preparing a mesoporous biodegradable composite fiber cloth containing tea residues according to claim 7, characterized in that: The preparation of the polypropylene succinate-polyethylene glycol-polymaleic anhydride elastomer comprises the following steps: Succinic acid and 1,3-propylene glycol are added to a reactor in a molar ratio of 1:1.1, 0.3-0.5 wt% of tetrabutyl titanate is added as a catalyst, and an esterification reaction is carried out at 180-190° C. for 3-4 hours. The water generated by the reaction is recovered to obtain a polypropylene succinate prepolymer; The poly(propylene succinate) prepolymer is cooled to 160-170° C., polyethylene glycol with an average molecular weight of 2000-4000 is added, and the added weight proportion of polyethylene glycol is 20-30 wt%. The polycondensation reaction is carried out under nitrogen protection for 2-3 hours to obtain a PBS-polyethylene glycol block prepolymer. A 1-3 wt% acetone solution of maleic anhydride is added dropwise to the PBS-polyethylene glycol block prepolymer and the reaction is continued at 100-120°C for 2 hours to allow the epoxy groups of the maleic anhydride to graft onto the hydroxyl groups of the polyethylene glycol, forming a block elastomer molecular chain structure with active side groups. The block elastomer molecular chain structure with active side groups was precipitated with ethanol and vacuum dried for 12 h to obtain poly(propylene succinate)-poly(ethylene glycol)-poly(maleic anhydride) elastomer with a molar mass of 6.2×10 4 ~8.5×10 4 g / mol, used as sheath material.

9. The method for preparing a mesoporous biodegradable composite fiber cloth containing tea residues according to claim 7, characterized in that: The S6 step specifically includes: S61. The tea residue core-sheath filaments, which retain a mesoporous structure, are fed into a drawing system and drawn once over a heated roller set at 60-65°C. The drawing speed is set at 80-100 m / min, and the draw ratio is controlled at 1.3-1.4 times to eliminate lattice defects in the nascent fibers and preliminarily orient the molecular segments. S62. The tea residue core-sheath filaments after primary drawing are continuously fed into a second set of heated rollers at a temperature of 90-96°C for secondary drawing. The drawing speed is set at 180-200 m / min, and the draw ratio is controlled at 1.3-1.4 times to align the stress directions of the core and sheath layers and form a stable mesoporous-capillary network structure. S63. The tea residue core-sheath filaments, after secondary drawing, were heat-set in a heat-setting apparatus at 120-122°C for 30 seconds to stabilize the polylactic acid / polybutylene succinate blend and the PBS-polyethylene glycol-PMG elastomer under thermal-tensile stress. S64. After heat setting, the filaments are cooled to room temperature and relaxed and wound up. The pore size distribution in the core layer of the obtained fiber filaments is maintained in the range of 2 to 20 nm, and the specific surface area is maintained in the range of 20 to 30 m 2 g -1 , fiber breaking strength ≥280N.