Soft environment-friendly knitted elastic fabric with good anti-deformation effect and preparation method

Abstract

The invention discloses a soft environment-friendly knitted elastic fabric with a good anti-deformation effect and a preparation method, and relates to the technical field of fiber textile fabrics, the fabric is characterized in that core-wrapped composite yarn is used as a raw material, the composite yarn uses bio-based block copolymerized spandex as core yarn and blended yarn of Lyocell fiber and bio-based PTT fiber as a coating layer, and the core-wrapped composite yarn and the coating layer are combined to form the core-wrapped composite yarn. The coating rate is 60%-70%; the composite yarn is woven into the fabric through a double-faced plain knitting structure, the knitting structure is a double-layer structure with different stitch lengths of a surface layer and an inner layer, the stitch length of the surface layer is set to be 4.0 stitches / cm, and the stitch length of the inner layer is set to be 3.2 stitches / cm; knitted grey cloth is sequentially subjected to enzymolysis softening finishing, atmospheric pressure plasma activating treatment, green cross-linking finishing treatment and natural plant oil agent setting treatment. The bio-based core-wrapped composite yarn has high resilience and environmental protection functions, solves the problem of poor environmental protection property of single chemical fiber elastic core polyester or spandex, improves the resilience rate, reduces COD (Chemical Oxygen Demand), and meets the requirements of elasticity and environmental protection.

Description

Technical Field

[0001] The invention relates to the technical field of fiber textile fabrics, in particular to an environmentally friendly knitted stretch fabric with good softness and good deformation resistance and a preparation method thereof. Background Art

[0002] Existing stretch knit fabrics generally rely on petroleum-based fibers and traditional chemical finishing. While they offer excellent initial elasticity, they become loose and deform after repeated stretching or washing. Furthermore, they are environmentally unfriendly, produce high COD levels in wastewater, and struggle to balance hand feel and breathability. With the increasing demand for functional apparel (sportswear, yoga, and medical compression garments) requiring high rebound, durability, anti-deformation properties, skin-friendly breathability, and environmental friendliness, there is an urgent need for simultaneous innovation across multiple processes, including raw materials, weaves, and finishing, to address the industry's pain point of achieving the trifecta of elasticity, environmental friendliness, and comfort.

[0003] Patent CN105401319B discloses a permanent elastic antibacterial warm knitted fabric. The above patent uses PTT polyester fiber to replace the spandex fiber in traditional knitted fabrics, which has the advantages of high strength, good elasticity and good thermal insulation effect. At the same time, antibacterial additives are added to the fabric, which has antibacterial function.

[0004] The above patented process is simple and has good stability, but cannot meet the multifunctional requirements of elasticity, comfort and environmental protection.

[0005] To this end, the present application proposes an environmentally friendly knitted stretch fabric and a preparation method thereof that is soft, has good deformation resistance and can take into account both elasticity and environmental protection. Summary of the Invention

[0006] The purpose of the present invention is to provide an environmentally friendly knitted stretch fabric with good deformation resistance and a preparation method, so as to solve the technical problems mentioned in the above background technology that existing stretch knitted fabrics generally rely on petroleum-based fibers and traditional chemical finishing. Although they have excellent initial elasticity, they become loose and deformed after repeated stretching or washing. At the same time, they are environmentally friendly, have high COD content in wastewater discharge, and are difficult to balance between hand feel and breathability.

[0007] To achieve the above object, the present invention provides the following technical solution: an environmentally friendly knitted stretch fabric with good softness and good deformation resistance, the fabric comprising: The core-wrapped composite yarn is made of bio-based segmented copolymer spandex as the core yarn and a blended yarn of Lyocell fiber and bio-based PTT fiber as the covering layer, with a covering rate of 60%-70%; The composite yarn is woven into a fabric through a double-sided plain knit structure, wherein the knitted structure is a double-layer structure with different stitch lengths for the surface layer and the inner layer, the stitch length of the surface layer is set to 4.0 stitches / cm, and the stitch length of the inner layer is set to 3.2 stitches / cm; The knitted fabric is sequentially subjected to enzymatic softening treatment, atmospheric pressure plasma activation treatment, green cross-linking finishing treatment and natural vegetable oil setting treatment.

[0008] Preferably, the segmented spandex core yarn has a segmented structural formula: [Polyether soft segment]-[Polyester hard segment]-[Polyether soft segment]; The polyester hard segment is polytrimethylene terephthalate (PTT) derived from biomass monomers, with a content of not less than 20% of the total mass of the core yarn, and a linear density controlled between 20D and 40D.

[0009] Preferably, the Lyocell fiber has a linear density of 1.2 dtex-1.7 dtex and a length of 38 mm-51 mm; Bio-based PTT fibers have a linear density of 2.0dtex-3.3dtex and a length of 38mm-64mm; The two fibers are blended in a volume ratio of 70:30 to form a covering layer.

[0010] Preferably, the core-wrapped composite yarn is produced by airflow coating or vortex spinning technology. The coating rate of the composite yarn is defined as the angular ratio of the coating layer fiber in the radial cross-section of the composite yarn, with a value range of 60%-70%, and the twist control of 45-60T / m is achieved through process control.

[0011] Preferably, the enzyme solution used in the enzymatic softening treatment process is a mixture of cellulase and hemicellulase, the cellulase concentration in the mixture is 1.0 g / L, the hemicellulase concentration is 0.5 g / L, the treatment temperature is 50°C, the treatment time is 15 min, the bath ratio is 1:20, and the fabric is rinsed with clean water and dehydrated on a spindle after treatment.

[0012] Preferably, the plasma activation treatment is carried out at normal pressure, using atmospheric pressure glow discharge technology, with an input power of 300 W and a frequency of 20 kHz, and the front and back sides of the knitted fabric are treated for 30 seconds each to increase the content of hydroxyl and carboxyl groups on the fiber surface and enhance the grafting efficiency of the subsequent cross-linking reaction.

[0013] Preferably, the crosslinking agent used in the green crosslinking finishing is a polycarboxylic acid renewable plant-derived small molecule, the crosslinking agent concentration is 1.5 g / L, the auxiliary catalyst is 0.2 g / L sodium perborate, the crosslinking temperature is 50°C, the crosslinking time is 10 min, and the bath ratio is 1:15.

[0014] Preferably, the natural oil agent is a tea seed oil emulsion or a coconut oil emulsion, the oil phase content in the emulsion is 5%, the emulsifier is a non-ionic plant-derived emulsifier, the applied concentration is 5 g / L, the treatment time is 10 minutes at room temperature, and it is dried at 100°C for 3 minutes to complete the surface shaping.

[0015] Preferably, the preparation method comprises the following steps: S1. Preparation of core-wrapped yarn: Spandex with a linear density of 20D-40D and a block structure containing a bio-based polyester segment was used as the core yarn. Lyocell and bio-based PTT were blended at a volume ratio of 70:30 to form a covering layer. The covering layer was spun by vortex spinning with a covering rate of 60%-70% and a twist of 50 T / m to obtain a core-wrapped composite yarn. S2. Knitting: using a double-faced plain knitting machine, knitting with core-wrapped composite yarn as the raw material, setting the surface layer needle gauge to 4.0 needles / cm, the inner layer needle gauge to 3.2 needles / cm, and the machine speed to 20 rpm to obtain the original fabric; S3. Enzymatic softening treatment: The grey cloth was treated in an enzyme solution containing 1.0 g / L cellulase and 0.5 g / L hemicellulase at 50°C and a bath ratio of 1:20 for 15 min to enhance the fiber's flexibility and washability. After treatment, the cloth was rinsed with clean water and dried. S4, plasma surface treatment: Place the enzymatically hydrolyzed blank into an atmospheric pressure plasma device and treat the front and back surfaces for 30 seconds each using a power of 300W to form active functional groups on the fiber surface; S5. Green cross-linking finishing: Immerse the activated fabric in a cross-linking bath containing 1.5g / L polycarboxylic acid cross-linking agent and 0.2g / L sodium perborate catalyst at 50°C and a bath ratio of 1:15 for 10 minutes to enhance the spatial stability and dimensional retention between fibers. S6. Oil setting finishing: Immerse the cross-linked fabric in a finishing solution containing 5g / L tea seed oil emulsion, treat it at room temperature for 10 minutes, and then dry it under hot air conditions at 100℃ for 3 minutes to form a smooth antistatic surface layer.

[0016] Preferably, dehydration and drying are performed between each processing step S1-S6 of the preparation method, and the moisture content of the fabric is controlled not to exceed 80% in the entire process to prevent excessive hydrolysis failure of the cross-linking reaction, and the final width shrinkage of the fabric is controlled within ±2%.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses a bio-based core-wrapped composite yarn to achieve both high resilience and environmental protection, solving the problem of poor environmental performance of single chemical fiber elastic core polyester or spandex. It improves the rebound rate, reduces COD, and takes into account both elasticity and environmental protection requirements. 2. This invention uses a differentiated double-sided plain knit structure to enhance mechanical support and breathability, solving the problem of rebound fatigue or insufficient breathability caused by improper matching of elastic yarn and weave. It maintains both support and breathability on the front and back, ensuring high rebound elasticity. 3. This invention uses enzymatic hydrolysis, plasma activation, and green cross-linking treatment to achieve a microscopic cross-linked network that locks the yarn into stable dimensions. This solves the problem that traditional cross-linking requires high temperature and high energy or toxic additives, and is prone to damaging the softness of the fiber. It enhances deformation resistance and improves softness and feel. 4. The present invention uses natural plant oils to shape the surface, achieving a smooth and anti-static effect, solving the problem of serious environmental pollution caused by chemical coatings or silicone oil finishing, which easily affects air permeability and touch, and improving anti-static smoothness and perspiration performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the preparation method of the present invention. DETAILED DESCRIPTION

[0019] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. Example 1

[0020] See also Figure 1 A soft, environmentally friendly knitted stretch fabric with good deformation resistance. Yarn preparation: core yarn: 20D block copolymer spandex (PTT) with a hard segment content of 20%; covering layer: Lyocell (1.5 dtex × 51 mm): bio-based PTT (3.0 dtex × 64 mm) = 70:30 (volume ratio); covering method: eddy current covering; covering rate: 65%, twist: 50 T / m; Knitting: Structure: double-sided plain weave; top layer needle spacing = 4.0 needles / cm, lining layer 3.2 needles / cm; machine speed 20rpm; Finishing: Enzymatic softening: 1.0 g / L cellulase + 0.5 g / L hemicellulase, 50°C, bath ratio 1:20, 15 min; Plasma activation: 300W, 20kHz, atmospheric pressure glow discharge, 30s on both sides; Green crosslinking: 1.5 g / L polycarboxylic acid + 0.2 g / L sodium perborate, 50°C, bath ratio 1:15, 10 min; Oil setting: 5g / L tea seed oil emulsion, room temperature for 10min, drying at 100℃ for 3min; The preparation method comprises the following steps: S1. Preparation of core-wrapped yarn: Spandex with a linear density of 20D-40D and a block structure containing a bio-based polyester segment was used as the core yarn. Lyocell and bio-based PTT were blended at a volume ratio of 70:30 to form a covering layer. The covering layer was spun by vortex spinning with a covering rate of 60%-70% and a twist of 50 T / m to obtain a core-wrapped composite yarn. S2. Knitting: using a double-faced plain knitting machine, knitting with core-wrapped composite yarn as the raw material, setting the surface layer needle gauge to 4.0 needles / cm, the inner layer needle gauge to 3.2 needles / cm, and the machine speed to 20 rpm to obtain the original fabric; S3. Enzymatic softening treatment: The grey cloth was treated in an enzyme solution containing 1.0 g / L cellulase and 0.5 g / L hemicellulase at 50°C and a bath ratio of 1:20 for 15 min to enhance the fiber's flexibility and washability. After treatment, the cloth was rinsed with clean water and dried. S4, plasma surface treatment: Place the enzymatically hydrolyzed blank into an atmospheric pressure plasma device and treat the front and back surfaces for 30 seconds each using a power of 300W to form active functional groups on the fiber surface; S5. Green cross-linking finishing: Immerse the activated fabric in a cross-linking bath containing 1.5g / L polycarboxylic acid cross-linking agent and 0.2g / L sodium perborate catalyst at 50°C and a bath ratio of 1:15 for 10 minutes to enhance the spatial stability and dimensional retention between fibers. S6. Oil setting finishing: Immerse the cross-linked fabric in a finishing solution containing 5g / L tea seed oil emulsion, treat at room temperature for 10 minutes, and then dry under 100℃ hot air conditions for 3 minutes to form a smooth antistatic surface layer; After obtaining the fabric, performance testing is carried out. Example 2

[0021] See also Figure 1 A soft, environmentally friendly knitted stretch fabric with good deformation resistance. Yarn preparation: core yarn: 20D block copolymer spandex (PTT) with a hard segment content of 20%; covering layer: Lyocell (1.5 dtex × 51 mm): bio-based PTT (3.0 dtex × 64 mm) = 70:30 (volume ratio); covering method: eddy current covering; covering rate: 70%, twist: 50 T / m; Knitting: Structure: double-sided plain weave; top layer needle spacing = 4.0 needles / cm, lining layer 3.2 needles / cm; machine speed 20rpm; Finishing: Enzymatic softening: 1.0 g / L cellulase + 0.5 g / L hemicellulase, 50°C, bath ratio 1:20, 15 min; Plasma activation: 300W, 20kHz, atmospheric pressure glow discharge, 30s on both sides; Green crosslinking: 1.5 g / L polycarboxylic acid + 0.2 g / L sodium perborate, 50°C, bath ratio 1:15, 10 min; Oil setting: 5g / L coconut oil emulsion, room temperature for 10min, drying at 100℃ for 3min; The preparation steps are the same as those in Example 1; After obtaining the fabric, performance testing is carried out. Example 3

[0022] See also Figure 1 A soft, environmentally friendly knitted stretch fabric with good deformation resistance. Yarn preparation: core yarn: 20D block copolymer spandex (PTT) with a hard segment content of 20%; covering layer: Lyocell (1.5 dtex × 51 mm): bio-based PTT (3.0 dtex × 64 mm) = 70:30 (volume ratio); covering method: eddy current covering; covering rate: 65%, twist: 50 T / m; Knitting: Structure: double-sided plain weave; top layer needle spacing = 4.0 needles / cm, lining layer 3.2 needles / cm; machine speed 20rpm; Finishing: Enzymatic softening: 1.2 g / L cellulase + 0.6 g / L hemicellulase, 50°C, bath ratio 1:20, 20 min; Plasma activation: 300W, 20kHz, atmospheric pressure glow discharge, 30s on both sides; Green crosslinking: 1.5 g / L polycarboxylic acid + 0.2 g / L sodium perborate, 50°C, bath ratio 1:15, 10 min; Oil setting: 5g / L tea seed oil emulsion, room temperature for 10min, drying at 100℃ for 3min; The preparation steps are the same as those in Example 1; After obtaining the fabric, performance testing is carried out. Example 4

[0023] See also Figure 1 A soft, environmentally friendly knitted stretch fabric with good deformation resistance. Yarn preparation: core yarn: 20D block copolymer spandex (PTT) with a hard segment content of 20%; covering layer: Lyocell (1.5 dtex × 51 mm): bio-based PTT (3.0 dtex × 64 mm) = 70:30 (volume ratio); covering method: eddy current covering; covering rate: 65%, twist: 50 T / m; Knitting: Structure: double-sided plain weave; top layer needle spacing = 4.0 needles / cm, lining layer 3.2 needles / cm; machine speed 20rpm; Finishing: Enzymatic softening: 1.0 g / L cellulase + 0.5 g / L hemicellulase, 50°C, bath ratio 1:20, 15 min; Plasma activation: 300W, 20kHz, atmospheric pressure glow discharge, 30s on both sides; Green crosslinking: 1.5 g / L citric acid-tartaric acid copolymer + 0.2 g / L sodium perborate, 50°C, bath ratio 1:15, 10 min; Oil setting: 5g / L tea seed oil emulsion, room temperature for 10min, drying at 100℃ for 3min; The preparation steps are the same as those in Example 1; After obtaining the fabric, performance testing is carried out. Example 5

[0024] See also Figure 1 A soft, environmentally friendly knitted stretch fabric with good deformation resistance. Yarn preparation: core yarn: 20D block copolymer spandex (PTT) with a hard segment content of 20%; covering layer: Lyocell (1.5 dtex × 51 mm): bio-based PTT (3.0 dtex × 64 mm) = 70:30 (volume ratio); covering method: eddy current covering; covering rate: 65%, twist: 50 T / m; Knitting: The structure is changed to double-layer warp knitting mesh: the surface warp knitting: the mesh size per unit area is about 1.5mm; the bottom weft knitting: maintains elasticity and rebound; the machine speed is 18rpm; Finishing: Enzymatic softening: 1.0 g / L cellulase + 0.5 g / L hemicellulase, 50°C, bath ratio 1:20, 15 min; Plasma activation: 300W, 20kHz, atmospheric pressure glow discharge, 30s on both sides; Green crosslinking: 1.5 g / L polycarboxylic acid + 0.2 g / L sodium perborate, 50°C, bath ratio 1:15, 10 min; Oil setting: 5g / L tea seed oil emulsion, room temperature for 10min, drying at 100℃ for 3min; The preparation steps are the same as those in Example 1; After obtaining the fabric, performance testing is carried out.

[0025] Performance testing and evaluation: Sample Preparation: For each test, 10cm x 30cm strips were cut from the finalized fabric. Five independent samples were prepared in each of the three directions (warp, weft, and diagonal). These samples were labeled and numbered. The "wash before test" method was used: pre-wash three times (water temperature 40°C, neutral detergent 5g / L, 30min wash and rinse each), then hung to dry naturally before testing. Tensile and rebound properties: Instron 5567 universal testing machine, 100 mm clamp spacing; test standard: ASTM D4964; test conditions: Single tensile rebound: Stretch at 10% strain rate, 100 mm / min, hold for 30 seconds, release, and rest for 60 seconds, and record the rebound rate; cyclic stretch performance: Repeated stretching 50 times under the same test conditions, record the recovery length at the first and 50th times, and calculate the permanent set rate; Tear strength: Elmendorf tear tester; test standard: ISO13937-2; test conditions: standard tongue-shaped specimens (length 200 mm, width 50 mm, center cut 100 mm), 10 sets each in warp and weft directions; tearing speed 100 mm / min; Abrasion resistance: Martindale abrasion tester; test standard: ISO12947-2; test conditions: applied pressure 12kPa, test medium: standard wool felt, cycle number 10,000 times; Pilling performance: Martindale pilling tester; test calibration: ISO12945-2; test conditions: applied pressure 12kPa, number of cycles 7500 times; Air permeability: FX3300 fabric air permeability tester; test standard: ISO9237; test conditions: pressure difference 100Pa, test area 20cm 3 ; Moisture wicking performance: Moisture Management Tester; Test standard: AATCC195; Test conditions: Ambient temperature 20±2°C, relative humidity 65±2%; Softness: Handle-O-Meter; Test standard: ASTM D1335; Test conditions: Specimen width 25mm, load 5N; Width and shrinkage: Test standard: ISO5077; Test conditions: pre-shrinkage (30 min soaking, room temperature drying), heat setting (120°C x 5 min); Wastewater discharge indicators: Test standard: GB 4287-2012; Test items and limits: COD ≤ 50 mg / L, suspended solids ≤ 20 mg / L, pH 6.0-9.0; Test method: COD is measured by closed reflux method, suspended solids are measured by gravimetric method, and pH meter is used for direct measurement.

[0026] illustrate: Coverage rate: the ratio of the composite yarn covering layer to the cross-sectional area; Enzymatic hydrolysis conditions: concentration of mixed enzyme solution and treatment time; Cross-linker type: The core chemical used in green cross-linking.

[0027] The test results are summarized in Table 1: Table 1 Test results Example Coverage rate (%) Rebound rate (%) Permanent deformation (%) Softness (mm) Air permeability (ml / m2·24h) Width shrinkage (%) 1 (baseline) 65 98.5 1.8 4.5 3200 +1.5 2 70 99.0 1.5 4.8 3150 +1.3 3 65 98.2 1.9 3.8 3300 +1.7 4 65 98.8 1.6 4.2 3250 +1.4 5 65 97.8 2.1 5.2 4500 +2.0 Working Principle: A block copolymer spandex containing ≥20% bio-based polyester hard segments is used as the core yarn, which is then coated with a Lyocell and bio-based PTT blended fiber to form an elastic core-natural regenerated sheath structure. The core yarn provides high resilience, while the sheath incorporates regenerated cellulose and bio-based polyester, enhancing skin-friendliness and softness while reducing the burden on the environment. The surface layer tightly supports the spandex core yarn, ensuring rapid rebound when stretched to 10%; the inner layer is relatively loose, enhancing the overall thickness, resilience and breathability of the fabric; this differentiated structure can still maintain the coordinated recovery between the fibers after multiple cycles of stretching; Cellulase and hemicellulase selectively etch the surface of the coating layer, increasing the fabric's looseness and capillary perspiration channels; hydroxyl and carboxyl functional groups are introduced on the fiber surface to provide reaction sites for subsequent cross-linking; polycarboxylic acid and sodium perborate form a microscopic cross-linked network structure on the surface of the activated fabric, locking the yarn position and resisting permanent deformation; tea seed oil emulsion forms a smooth layer on the fiber surface, improving touch, anti-static and fine-tuning the fabric feel.

[0028] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A soft, environmentally friendly knitted stretch fabric with good deformation resistance, characterized by: The fabrics include: The core-wrapped composite yarn is made of bio-based segmented copolymer spandex as the core yarn and a blended yarn of Lyocell fiber and bio-based PTT fiber as the covering layer, with a covering rate of 60%-70%; The composite yarn is woven into a fabric through a double-sided plain knit structure, wherein the knitted structure is a double-layer structure with different stitch lengths for the surface layer and the inner layer, the stitch length of the surface layer is set to 4.0 stitches / cm, and the stitch length of the inner layer is set to 3.2 stitches / cm; The knitted fabric is sequentially subjected to enzymatic softening treatment, atmospheric pressure plasma activation treatment, green cross-linking finishing treatment and natural vegetable oil setting treatment.

2. The environmentally friendly knitted stretch fabric with good softness and good deformation resistance according to claim 1, characterized in that: The segmented spandex core yarn has a segmented structural formula: [Polyether soft segment]-[Polyester hard segment]-[Polyether soft segment]; The polyester hard segment is polytrimethylene terephthalate (PTT) derived from biomass monomers, with a content of not less than 20% of the total mass of the core yarn, and a linear density controlled between 20D and 40D.

3. The environmentally friendly knitted stretch fabric with good softness and good deformation resistance according to claim 1, characterized in that: The Lyocell fiber has a linear density of 1.2 dtex-1.7 dtex and a length of 38 mm-51 mm; Bio-based PTT fibers have a linear density of 2.0dtex-3.3dtex and a length of 38mm-64mm; The two fibers are blended in a volume ratio of 70:30 to form a covering layer.

4. The environmentally friendly knitted stretch fabric with good softness and good deformation resistance according to claim 1, characterized in that: The core-wrapped composite yarn is produced by airflow covering or vortex spinning technology. The covering rate of the composite yarn is defined as the angular ratio of the covering layer fiber in the radial cross-section of the composite yarn, with a value range of 60%-70%, and the twist control of 45-60T / m is achieved through process control.

5. The environmentally friendly knitted stretch fabric with good softness and good deformation resistance according to claim 1, characterized in that: The enzyme solution used in the enzymatic softening process is a mixture of cellulase and hemicellulase, wherein the cellulase concentration in the mixture is 1.0 g / L and the hemicellulase concentration is 0.5 g / L, the treatment temperature is 50° C., the treatment time is 15 min, and the bath ratio is 1:

20. After treatment, the fabric is rinsed with clean water and dehydrated by a spindle.

6. The environmentally friendly knitted stretch fabric with good softness and good deformation resistance according to claim 1, characterized in that: The plasma activation treatment is carried out at normal pressure using atmospheric pressure glow discharge technology with an input power of 300 W and a frequency of 20 kHz. The front and back sides of the knitted fabric are treated for 30 seconds each to increase the content of hydroxyl and carboxyl groups on the fiber surface and enhance the grafting efficiency of the subsequent cross-linking reaction.

7. The environmentally friendly knitted stretch fabric with good softness and good deformation resistance according to claim 1, characterized in that: The crosslinking agent used in the green crosslinking finishing is a polycarboxylic acid renewable plant-derived small molecule, the crosslinking agent concentration is 1.5 g / L, the auxiliary catalyst is 0.2 g / L sodium perborate, the crosslinking temperature is 50° C., the crosslinking time is 10 min, and the bath ratio is 1:

15.

8. The environmentally friendly knitted stretch fabric with good softness and good deformation resistance according to claim 1, characterized in that: The natural oil agent is a tea seed oil emulsion or a coconut oil emulsion, the oil phase content in the emulsion is 5%, the emulsifier is a non-ionic plant-derived emulsifier, the applied concentration is 5g / L, the treatment time is 10 minutes at room temperature, and it is dried at 100°C for 3 minutes to complete surface shaping.

9. A method for preparing a soft, environmentally friendly, and anti-deformation knitted stretch fabric, suitable for preparing the soft, environmentally friendly, and anti-deformation knitted stretch fabric according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: S1. Preparation of core-wrapped yarn: Spandex with a linear density of 20D-40D and a block structure containing a bio-based polyester segment was used as the core yarn. Lyocell and bio-based PTT were blended at a volume ratio of 70:30 to form a covering layer. The covering layer was spun by vortex spinning with a covering rate of 60%-70% and a twist of 50 T / m to obtain a core-wrapped composite yarn. S2. Knitting: using a double-faced plain knitting machine, knitting with core-wrapped composite yarn as the raw material, setting the surface layer needle gauge to 4.0 needles / cm, the inner layer needle gauge to 3.2 needles / cm, and the machine speed to 20 rpm to obtain the original fabric; S3. Enzymatic softening treatment: The grey cloth was treated in an enzyme solution containing 1.0 g / L cellulase and 0.5 g / L hemicellulase at 50°C and a bath ratio of 1:20 for 15 min to enhance the fiber's flexibility and washability. After treatment, the cloth was rinsed with clean water and dried. S4, plasma surface treatment: Place the enzymatically hydrolyzed blank into an atmospheric pressure plasma device and treat the front and back surfaces for 30 seconds each using a power of 300W to form active functional groups on the fiber surface; S5. Green cross-linking finishing: Immerse the activated fabric in a cross-linking bath containing 1.5g / L polycarboxylic acid cross-linking agent and 0.2g / L sodium perborate catalyst at 50°C and a bath ratio of 1:15 for 10 minutes to enhance the spatial stability and dimensional retention between fibers. S6. Oil setting finishing: Immerse the cross-linked fabric in a finishing solution containing 5g / L tea seed oil emulsion, treat it at room temperature for 10 minutes, and then dry it under hot air conditions at 100℃ for 3 minutes to form a smooth antistatic surface layer.

10. The method for preparing a soft and environmentally friendly knitted stretch fabric with good deformation resistance according to claim 9, characterized in that: In the preparation method S1-S6, dehydration and drying are performed between each processing step, and the moisture content of the fabric is controlled not to exceed 80% throughout the entire process to prevent excessive hydrolysis failure of the cross-linking reaction. Finally, the width shrinkage of the fabric is controlled within ±2%.

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