Environment-friendly silk fabric low-temperature plasma anti-wrinkle finishing process

Abstract

The invention discloses an environment-friendly silk fabric low-temperature plasma anti-wrinkle finishing process, and particularly relates to the technical field of biopolymer engineering. The process sequentially comprises the steps of pre-cleaning, low-temperature plasma activation, polyproline solution impregnation, roll compacting and pre-drying, acetylation treatment, neutralization and soaping, dehydration and drying and the like. Performing micro-etching and activation on the surface of the silk through oxygen low-temperature plasma to increase reaction sites; constructing a biological cross-linked network imitating the elasticity of spider silk on the surface of the fiber by utilizing polyproline with a II-type helical structure; unreacted amino groups are sealed through acetylation treatment, so that the hydrophobicity and the network stability are enhanced. The process does not need to use formaldehyde resin, keeps high breaking strength retention rate and washable stability while realizing excellent wrinkle resistance, has the comprehensive advantages of environmental protection and excellent durability, and is suitable for wrinkle-resistant function finishing of high-end silk products.

Description

Technical Field

[0001] This invention relates to the field of biopolymer engineering technology, and specifically to an environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics. Background Technology

[0002] As a natural protein fiber, silk has a loose molecular chain structure and lacks sufficient lateral cross-linking, making the fabric extremely prone to wrinkling during actual use, severely affecting its appearance and high-end performance. While traditional anti-wrinkle finishing can improve this problem to some extent, it often comes at the cost of silk's unique softness and wearing comfort, thus limiting the application of silk products in high-quality clothing and home furnishings.

[0003] For a long time, anti-wrinkle finishing of silk has mainly relied on aldehyde-containing resin finishing agents, such as dimethyloldihydroxyvinyl urea. Although these finishing agents can impart a certain degree of wrinkle resistance to fabrics through covalent cross-linking, they easily release free formaldehyde during the finishing process, leading to the risk of formaldehyde residue in textiles. This does not meet the increasingly stringent standards for eco-textiles and the demands for healthy consumption. In addition, the production and application of aldehyde-containing resins involve environmental pollution, making it difficult to adapt to the industry trends of green textiles and sustainable development.

[0004] Traditional resin finishing agents form a rigid covalent cross-linked network within the fiber, which, while improving wrinkle resistance, severely damages the natural conformation and molecular chain flexibility of silk proteins, leading to a significant decrease in fiber strength and loss of elasticity. This "damage-for-function" finishing method not only reduces the fabric's lifespan but also limits its application in fields with extremely high requirements for material biocompatibility and mechanical integrity, such as medical, skincare, and high-end lingerie. Therefore, there is an urgent need for a new finishing process that can effectively resist wrinkles while also ensuring fiber health and environmental safety. Summary of the Invention

[0005] In order to overcome the above-mentioned defects of the prior art, the embodiments of the present invention provide an environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics, which solves the problems of silk being prone to wrinkling, traditional anti-wrinkle processes for silk relying on formaldehyde resins, and traditional processes severely damaging the macromolecular structure of silk fibers through cross-linking.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics includes the following steps:

[0008] S1: Soak the silk in a neutral soap flake solution and heat it. Then, wash the treated silk thoroughly in warm water. Finally, dry the washed silk in an oven to obtain pre-cleaned silk.

[0009] S2: The pre-cleaned silk obtained in S1 is placed in a radio frequency glow discharge low-temperature plasma device and the silk is laid flat on the electrodes of the processing chamber and the chamber is sealed. After the reaction is completed, plasma-activated silk is obtained.

[0010] S3: Prepare a polyproline solution using phosphate buffer, then immerse the plasma-activated silk in the polyproline solution at a ratio of 1:20 of silk to polyproline solution and stir at 30 rpm for 30 minutes to obtain impregnated silk.

[0011] S4: Roll the impregnated silk and control the liquid content, then place the silk in an oven for pre-drying, then raise the temperature of the oven and keep it warm;

[0012] S5: Acetic anhydride and glacial acetic acid are mixed to prepare an acetylation treatment solution. The silkworms baked in S4 are then immersed in the acetylation treatment solution and then placed in a constant temperature water bath for heat preservation.

[0013] S6: Rinse the silk treated in S5 with cold water, then soak the silk in sodium bicarbonate solution at a bath ratio of 1:30, then soap the silk in a neutral soap flake solution, and finally wash the silk with warm water.

[0014] S7: Place the silk washed with warm water in S6 into a centrifugal dehydrator at 1000 rpm for 3 minutes to dehydrate, and then spread the dehydrated silk out in a forced-air drying oven at 70℃ to dry to constant weight.

[0015] S8: The silk was subjected to fabric wrinkle recovery angle test, breaking strength test, and simulated 5 household washing tests in sequence to verify the durability of the wrinkle resistance effect.

[0016] Preferably, in step S1, the silk fabric is soaked in a neutral soap flake solution at a bath ratio of 1:30 to 1:50, and then the solution is heated to 95 to 100°C and kept warm for 60 minutes.

[0017] Preferably, in step S1, the treated silk is washed thoroughly in warm water at 35-40°C for 5 minutes, and finally the washed silk is dried in an oven at a relative humidity of 65±4% and a temperature of 60°C for 24 hours.

[0018] Preferably, in S2, the operating power of the low-temperature plasma device is set to 80W, the cavity gas is oxygen, the cavity gas pressure is 30~50Pa, and the operating time is 5 minutes.

[0019] Preferably, the phosphate buffer used in S3 is a 0.1M pH 6.5 buffer, followed by the addition of polyproline with a molecular weight of 3000~10000 to prepare a 1.0~2.0% (w / v) solution.

[0020] Preferably, in step S4, the impregnated silk is rolled under a uniform pressure of 0.3~0.5MPa and the liquid content of the silk is controlled to reach 80±5%. Then, the silk is placed in an oven at 80℃ for pre-drying for 5~10 minutes, and finally the temperature inside the oven is raised to 130℃ for drying for 4~5 minutes.

[0021] Preferably, in step S5, acetic anhydride and glacial acetic acid are uniformly mixed in a volume ratio of 1:4 to obtain an acetylation treatment solution.

[0022] Preferably, in step S5, the baked silk is thoroughly soaked in the acetylation treatment solution at a bath ratio of 1:5, and then the mixture is placed in a constant temperature water bath at 60°C for 60 minutes.

[0023] Preferably, in step S6, the acetylated silk is first rinsed with water at 10-15°C for 10 minutes, then the silk is soaked in a sodium bicarbonate solution with a concentration of 1-2% (w / v) at a bath ratio of 1:30 for 15 minutes, then the silk is soaped in a neutral soap flake solution at 60°C with a concentration of 1-1.2 g / L for 10-15 minutes, and finally the silk is washed with warm water at 50±2°C.

[0024] Preferably, in step S7, the silk washed with warm water is placed in a centrifugal dehydrator at 1000-1500 rpm for 3-5 minutes to dehydrate, and finally the dehydrated silk is laid flat in a forced-air drying oven at 70℃ to dry to constant weight.

[0025] The technical effects and advantages of the environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics of this invention are as follows:

[0026] 1. The invention utilizes the high strength of spider silk, which is rich in β-sheet structure in its protein. Polyproline has a type II helical conformation, which can form a rigid-elastic alternating network similar to spider silk on the fiber surface. This application constructs a biomimetic elastic network structure by directional adsorption and cross-linking of polyproline on the surface of plasma-activated silk, which significantly improves the resilience and wrinkle resistance of the fabric.

[0027] 2. This invention uses oxygen low-temperature plasma to perform micro-etching and hydrophilic modification on the surface of silk, increasing surface active sites, improving the adsorption and cross-linking efficiency of polyproline, and realizing biomimetic interface engineering.

[0028] 3. In this invention, the rigid helical structure of polyproline acts as a molecular spring in the cross-linked network, dissipating energy through conformational changes during deformation. This structure enables silk to recover quickly after wrinkling, with the wrinkle recovery angle increased to 285°. Even after multiple washes, it still maintains a 92% recovery rate, exhibiting the durable elasticity of spider silk.

[0029] 4. This invention converts unreacted amino groups into hydrophobic acetyl groups through acetylation treatment, constructs a biomimetic hydrophobic outer layer, reduces the moisture absorption and swelling of fibers, thereby stabilizing the cross-linking network and significantly improving wrinkle resistance and durability.

[0030] 5. This invention uses polyproline and low-temperature plasma, avoiding the use of formaldehyde resins, and the process wastewater is easy to treat, which is in line with the development direction of green textiles and realizes a bio-inspired and environmentally friendly finishing strategy.

[0031] 6. This invention improves wrinkle resistance while retaining 95% of the breaking strength, which is far higher than the 80% of traditional 2D resin finishing. It also avoids fiber embrittlement and hardening, making it suitable for high-end medical and skincare silk products.

[0032] 7. This invention, through acetylation treatment, converts unreacted amino groups in the cross-linked network into hydrophobic acetyl groups, significantly improving the washability and durability of the finishing effect. This step not only stabilizes the bio-cross-linked network formed between polyproline and fiber, preventing hydrogen bond relaxation or protonation damage in a humid environment, but also inhibits fiber swelling caused by water intrusion by reducing the hydrophilicity of the fiber surface, thereby constructing a hydrophobic protective layer at the molecular level. Attached Figure Description

[0033] Figure 1 This is a flowchart of an environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics proposed in this invention. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0036] Example 1

[0037] This embodiment provides an environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics, the specific implementation steps of which include:

[0038] Experimental materials:

[0039] 100 parts by weight of silk fabric, 3000-5000 parts by weight of neutral soap flake solution, 1900-2100 parts by weight of 0.1M pH 6.5 phosphate buffer, 19-21 parts by weight of polyproline with a molecular weight of 3000-10000, 30-50 parts by weight of acetic anhydride, 120-200 parts by weight of glacial acetic acid, and 3000-5000 parts by weight of 2% (w / v) sodium bicarbonate solution.

[0040] Experimental objective:

[0041] Low-temperature plasma is used to perform an environmentally friendly anti-wrinkle finishing on silk fabrics.

[0042] Experimental steps:

[0043] S1: Soak the silk fabric in a neutral soap flake solution at a bath ratio of 1:30~1:50. Then heat the solution to 95~100℃ and keep it warm for 60 minutes. After the treatment, wash the silk fabric thoroughly in warm water at 35~40℃ for 5 minutes. Finally, dry the fabric in an oven with an ambient relative humidity of 65±4% and an ambient temperature of 60℃ for 24 hours to obtain pre-cleaned silk.

[0044] S2: The pre-cleaned silk obtained in S1 is placed in a radio frequency glow discharge low-temperature plasma device and the fabric is laid flat on the electrodes of the processing chamber in a single layer. The chamber is sealed, and then the working power of the low-temperature plasma device is set to 80W, the chamber gas is oxygen, the chamber pressure is 30Pa, and the working time is 5 minutes to obtain plasma-activated silk.

[0045] S3: Prepare a 1.0% (w / v) polyproline solution with a molecular weight of 3000~10000 using 0.1M phosphate buffer solution with pH 6.5. Then, immerse the plasma-activated silk in the polyproline solution at a bath ratio of fabric:polyproline solution = 1:20 and stir at 30 rpm for 30 minutes to obtain impregnated silk.

[0046] S4: Roll the impregnated silk under a uniform pressure of 0.3MPa and control the liquid content at 80±5%. Then, place the silk in an oven at 80℃ for pre-drying for 5 minutes. Then, raise the temperature of the oven to 130℃ and keep it warm for 4 minutes.

[0047] S5: Prepare an acetylation treatment solution by mixing acetic anhydride and glacial acetic acid in a volume ratio of 1:4. Then, immerse the fabric baked in S4 into the acetylation treatment solution in a bath ratio of 1:5, and then place it in a constant temperature water bath at 60°C for 60 minutes.

[0048] S6: Rinse the fabric treated in S5 with cold water at 10°C for 10 minutes, then soak the fabric in a 2% (w / v) sodium bicarbonate solution at a bath ratio of 1:30 for 15 minutes, then soap the fabric in a 60°C, 1g / L neutral soap flake solution for 10 minutes, and finally wash the silk with warm water at 50°C.

[0049] S7: Place the silk washed with warm water in S6 into a centrifugal dehydrator at 1000 rpm for 3 minutes to dehydrate, and then spread the dehydrated silk out in a forced-air drying oven at 70℃ to dry to constant weight.

[0050] S8: The fabric will be subjected to fabric wrinkle recovery angle test, breaking strength test and simulated 5 household washing tests in sequence to verify the durability of wrinkle resistance.

[0051] Experimental results: See Table 1 for details.

[0052] Table 1: Test Results of Example 1

[0053] Wrinkle recovery angle test (longitude + latitude, °) Fracture strength (meridian, N) / retention rate Recovery angle retention rate after 5 washes Example 1 285 420 / 95% 92%

[0054] This embodiment employs a three-step synergistic process of plasma activation, polyproline crosslinking, and acetylation reinforcement. Mechanistically, the active particles generated by radio frequency glow discharge introduce hydrophilic groups and micro-etching on the fiber surface, significantly increasing the number of reaction sites. Subsequently, polyproline with a rigid type II helical structure forms ionic and hydrogen bonds with the activated amino / hydroxyl groups on the fiber surface through its carboxyl groups, constructing a three-dimensional elastic bio-crosslinked network. The final acetylation treatment converts unreacted amino groups in the network into hydrophobic acetyl groups, which not only stabilizes the crosslinked structure but also reduces the fiber's hygroscopic swelling. Thus, at the molecular level, physical activation, bio-conformation crosslinking, and chemical stabilization are synergistically achieved. This allows the fiber to maintain a high tensile strength retention rate while achieving excellent initial wrinkle resistance and washability, demonstrating the mechanistic superiority of this process in constructing a durable, elastic, and environmentally friendly crosslinked network.

[0055] Example 2

[0056] This embodiment provides an environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics, the specific implementation steps of which include:

[0057] Experimental materials:

[0058] 100 parts by weight of silk fabric, 3000-5000 parts by weight of neutral soap flake solution, 1900-2100 parts by weight of 0.1M pH 6.5 phosphate buffer, 19-21 parts by weight of polyproline with a molecular weight of 3000-10000, 30-50 parts by weight of acetic anhydride, 120-200 parts by weight of glacial acetic acid, and 3000-5000 parts by weight of 2% (w / v) sodium bicarbonate solution.

[0059] Experimental objective:

[0060] The effect of reducing plasma power on plasma treatment intensity was investigated.

[0061] Experimental steps:

[0062] S1: Soak the silk fabric in a neutral soap flake solution at a bath ratio of 1:30~1:50. Then heat the solution to 95~100℃ and keep it warm for 60 minutes. After the treatment, wash the silk fabric thoroughly in warm water at 35~40℃ for 5 minutes. Finally, dry the fabric in an oven with an ambient relative humidity of 65±4% and an ambient temperature of 60℃ for 24 hours to obtain pre-cleaned silk.

[0063] S2: The pre-cleaned silk obtained in S1 is placed in a radio frequency glow discharge low-temperature plasma device and the fabric is laid flat on the electrodes of the processing chamber in a single layer. The chamber is sealed, and then the working power of the low-temperature plasma device is set to 50W, the chamber gas is oxygen, the chamber pressure is 30Pa, and the working time is 2 minutes to obtain plasma-activated silk.

[0064] S3: Prepare a 1.0% (w / v) polyproline solution with a molecular weight of 3000~10000 using 0.1M phosphate buffer solution with pH 6.5. Then, immerse the plasma-activated silk in the polyproline solution at a bath ratio of fabric:polyproline solution = 1:20 and stir at 30 rpm for 30 minutes to obtain impregnated silk.

[0065] S4: Roll the impregnated silk under a uniform pressure of 0.3MPa and control the liquid content at 80±5%. Then, place the silk in an oven at 80℃ for pre-drying for 5 minutes. Then, raise the temperature of the oven to 130℃ and keep it warm for 4 minutes.

[0066] S5: Prepare an acetylation treatment solution by mixing acetic anhydride and glacial acetic acid in a volume ratio of 1:4. Then, immerse the fabric baked in S4 into the acetylation treatment solution in a bath ratio of 1:5, and then place it in a constant temperature water bath at 60°C for 60 minutes.

[0067] S6: Rinse the fabric treated in S5 with cold water at 10°C for 10 minutes, then soak the fabric in a 2% (w / v) sodium bicarbonate solution at a bath ratio of 1:30 for 15 minutes, then soap the fabric in a 60°C, 1g / L neutral soap flake solution for 10 minutes, and finally wash the silk with warm water at 50°C.

[0068] S7: Place the silk washed with warm water in S6 into a centrifugal dehydrator at 1000 rpm for 3 minutes to dehydrate, and then spread the dehydrated silk out in a forced-air drying oven at 70℃ to dry to constant weight.

[0069] S8: The fabric will be subjected to fabric wrinkle recovery angle test, breaking strength test and simulated 5 household washing tests in sequence to verify the durability of wrinkle resistance.

[0070] Experimental results: See Table 2 for details.

[0071] Table 2: Test Results of Example 2

[0072] Wrinkle recovery angle test (longitude + latitude, °) Fracture strength (meridian, N) / retention rate Recovery angle retention rate after 5 washes Example 2 235 430 / 97% 85%

[0073] This embodiment reduces plasma treatment power and time, resulting in insufficient physicochemical activation of the fiber surface. Mechanistically, the weaker plasma treatment cannot effectively open the crystal structure of the fiber surface and generate sufficient active sites, thus limiting the accessibility and reactivity of subsequent polyproline molecules. Although the mild treatment results in minimal fiber damage and the highest strength retention rate, the sparse cross-linked network cannot effectively resist fiber slippage and deformation, leading to a significant decrease in both the initial wrinkle recovery angle and the retention rate after washing.

[0074] Example 3

[0075] This embodiment provides an environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics, the specific implementation steps of which include:

[0076] Experimental materials:

[0077] 100 parts by weight of silk fabric, 3000-5000 parts by weight of neutral soap flake solution, 1900-2100 parts by weight of 0.1M pH 6.5 phosphate buffer, 19-21 parts by weight of polylysine with a molecular weight of 3000-10000, 30-50 parts by weight of acetic anhydride, 120-200 parts by weight of glacial acetic acid, and 3000-5000 parts by weight of 2% (w / v) sodium bicarbonate solution.

[0078] Experimental objective:

[0079] The effect of replacing polyproline with an equal amount of polylysine on the three-dimensional cross-linked network was investigated.

[0080] Experimental steps:

[0081] S1: Soak the silk fabric in a neutral soap flake solution at a bath ratio of 1:30~1:50. Then heat the solution to 95~100℃ and keep it warm for 60 minutes. After the treatment, wash the silk fabric thoroughly in warm water at 35~40℃ for 5 minutes. Finally, dry the fabric in an oven with an ambient relative humidity of 65±4% and an ambient temperature of 60℃ for 24 hours to obtain pre-cleaned silk.

[0082] S2: The pre-cleaned silk obtained in S1 is placed in a radio frequency glow discharge low-temperature plasma device and the fabric is laid flat on the electrodes of the processing chamber in a single layer. The chamber is sealed, and then the working power of the low-temperature plasma device is set to 80W, the chamber gas is oxygen, the chamber pressure is 30Pa, and the working time is 5 minutes to obtain plasma-activated silk.

[0083] S3: Prepare a 1.0% (w / v) polylysine solution with a molecular weight of 3000~10000 using 0.1M phosphate buffer solution with pH 6.5. Then, immerse the plasma-activated silk in the polylysine solution at a bath ratio of fabric:polylysine solution = 1:20 and stir at 30 rpm for 30 minutes to obtain impregnated silk.

[0084] S4: Roll the impregnated silk under a uniform pressure of 0.3MPa and control the liquid content at 80±5%. Then, place the silk in an oven at 80℃ for pre-drying for 5 minutes. Then, raise the temperature of the oven to 130℃ and keep it warm for 4 minutes.

[0085] S5: Prepare an acetylation treatment solution by mixing acetic anhydride and glacial acetic acid in a volume ratio of 1:4. Then, immerse the fabric baked in S4 into the acetylation treatment solution in a bath ratio of 1:5, and then place it in a constant temperature water bath at 60°C for 60 minutes.

[0086] S6: Rinse the fabric treated in S5 with cold water at 10°C for 10 minutes, then soak the fabric in a 2% (w / v) sodium bicarbonate solution at a bath ratio of 1:30 for 15 minutes, then soap the fabric in a 60°C, 1g / L neutral soap flake solution for 10 minutes, and finally wash the silk with warm water at 50°C.

[0087] S7: Place the silk washed with warm water in S6 into a centrifugal dehydrator at 1000 rpm for 3 minutes to dehydrate, and then spread the dehydrated silk out in a forced-air drying oven at 70℃ to dry to constant weight.

[0088] S8: The fabric will be subjected to fabric wrinkle recovery angle test, breaking strength test and simulated 5 household washing tests in sequence to verify the durability of wrinkle resistance.

[0089] Experimental results: See Table 3 for details.

[0090] Table 3: Test Results of Example 3

[0091] Wrinkle recovery angle test (longitude + latitude, °) Fracture strength (meridian, N) / retention rate Recovery angle retention rate after 5 washes Example 3 250 400 / 91% 82%

[0092] In this embodiment, linear polylysine is used instead of polyproline, which has a helical structure. Mechanistically, although polylysine, as a linear flexible molecular chain, can crosslink with the carboxyl groups of the fiber through its amino groups, the network formed lacks the three-dimensional conformational support and entropic elasticity provided by the rigid helical structure unique to polyproline. This linear crosslinked network is more prone to plastic deformation under stress, and its hydrophilic side chains may exacerbate fiber swelling. Therefore, although a certain degree of crosslinking can be formed, the final wrinkle resistance and wash retention rate are not as good as in Example 1.

[0093] Example 4

[0094] This embodiment provides an environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics, the specific implementation steps of which include:

[0095] Experimental materials:

[0096] 100 parts by weight of silk fabric, 3000-5000 parts by weight of neutral soap flake solution, 1900-2100 parts by weight of 0.1M pH 6.5 phosphate buffer, 19-21 parts by weight of polyproline with a molecular weight of 3000-10000, 30-50 parts by weight of acetic anhydride, 120-200 parts by weight of glacial acetic acid, and 3000-5000 parts by weight of 2% (w / v) sodium bicarbonate solution.

[0097] Experimental objective:

[0098] To explore the anti-wrinkle finishing process of silk fabrics without acetylation treatment.

[0099] Experimental steps:

[0100] S1: Soak the silk fabric in a neutral soap flake solution at a bath ratio of 1:30~1:50. Then heat the solution to 95~100℃ and keep it warm for 60 minutes. After the treatment, wash the silk fabric thoroughly in warm water at 35~40℃ for 5 minutes. Finally, dry the fabric in an oven with an ambient relative humidity of 65±4% and an ambient temperature of 60℃ for 24 hours to obtain pre-cleaned silk.

[0101] S2: The pre-cleaned silk obtained in S1 is placed in a radio frequency glow discharge low-temperature plasma device and the fabric is laid flat on the electrodes of the processing chamber in a single layer. The chamber is sealed, and then the working power of the low-temperature plasma device is set to 80W, the chamber gas is oxygen, the chamber pressure is 30Pa, and the working time is 5 minutes to obtain plasma-activated silk.

[0102] S3: Prepare a 1.0% (w / v) polyproline solution with a molecular weight of 3000~10000 using 0.1M phosphate buffer solution with pH 6.5. Then, immerse the plasma-activated silk in the polyproline solution at a bath ratio of fabric:polyproline solution = 1:20 and stir at 30 rpm for 30 minutes to obtain impregnated silk.

[0103] S4: Roll the impregnated silk under a uniform pressure of 0.3MPa and control the liquid content at 80±5%. Then, place the silk in an oven at 80℃ for pre-drying for 5 minutes. Then, raise the temperature of the oven to 130℃ and keep it warm for 4 minutes.

[0104] S5: Rinse the fabric treated in S4 with cold water at 10°C for 10 minutes, then soak the fabric in a 2% (w / v) sodium bicarbonate solution at a bath ratio of 1:30 for 15 minutes, then soap the fabric in a 60°C, 1g / L neutral soap flake solution for 10 minutes, and finally wash the silk with warm water at 50°C.

[0105] S6: Place the silk washed with warm water in S5 into a centrifugal dehydrator at 1000 rpm for 3 minutes to dehydrate. Then, spread the dehydrated silk out in a forced-air drying oven at 70℃ and dry it to constant weight.

[0106] S7: The fabric will be subjected to fabric wrinkle recovery angle test, breaking strength test and simulated 5 household washing tests in sequence to verify the durability of wrinkle resistance.

[0107] Experimental results: See Table 4 for details.

[0108] Table 4: Test Results of Example 4

[0109] Wrinkle recovery angle test (longitude + latitude, °) Fracture strength (meridian, N) / retention rate Recovery angle retention rate after 5 washes Example 4 270 435 / 99% 75%

[0110] In this embodiment, the acetylation reinforcement step was omitted after the polyproline crosslinking. Mechanistically, a large number of unclosed amino groups in the crosslinking network are very likely to form new hydrogen bonds or undergo protonation with water molecules during subsequent wet treatment, resulting in reversible relaxation or destruction of the crosslinking network. This makes the finishing effect unstable in the water environment, as the wrinkle resistance retention rate drops sharply to 75% after 5 washes, even though the fiber damage is minimized and the strength retention rate is as high as 99% due to the avoidance of acid treatment.

[0111] Example 5

[0112] This embodiment provides an environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics, the specific implementation steps of which include:

[0113] Experimental materials:

[0114] 100 parts by weight of silk fabric, 3000-5000 parts by weight of neutral soap flake solution, 1900-2100 parts by weight of 0.1M pH 6.5 phosphate buffer, 19-21 parts by weight of polyproline with a molecular weight of 3000-10000, 30-50 parts by weight of acetic anhydride, 120-200 parts by weight of glacial acetic acid, and 3000-5000 parts by weight of 2% (w / v) sodium bicarbonate solution.

[0115] Experimental objective:

[0116] This study explores the scientific validity and necessity of adjusting the order of the three-step process of activation-crosslinking-reinforcement.

[0117] Experimental steps:

[0118] S1: Soak the silk fabric in a neutral soap flake solution at a bath ratio of 1:30~1:50. Then heat the solution to 95~100℃ and keep it warm for 60 minutes. After the treatment, wash the silk fabric thoroughly in warm water at 35~40℃ for 5 minutes. Finally, dry the fabric in an oven with an ambient relative humidity of 65±4% and an ambient temperature of 60℃ for 24 hours to obtain pre-cleaned silk.

[0119] S2: Acetic anhydride and glacial acetic acid were mixed in a volume ratio of 1:4 to prepare an acetylation treatment solution. Then, pre-washed silk was immersed in the acetylation treatment solution at a bath ratio of 1:5 and then placed in a constant temperature water bath at 60°C for 60 minutes.

[0120] S3: Rinse the fabric treated in S2 with cold water at 10°C for 10 minutes, then soak the fabric in a 2% (w / v) sodium bicarbonate solution at a bath ratio of 1:30 for 15 minutes, then soap the fabric in a 60°C, 1g / L neutral soap flake solution for 10 minutes, and finally wash the silk with warm water at 50°C.

[0121] S4: The pre-cleaned silk obtained in S3 is placed in a radio frequency glow discharge low-temperature plasma device and the fabric is laid flat on the electrodes of the processing chamber in a single layer. The chamber is sealed, and then the working power of the low-temperature plasma device is set to 80W, the chamber gas is oxygen, the chamber pressure is 30Pa, and the working time is 5 minutes to obtain plasma-activated silk.

[0122] S5: Prepare a 1.0% (w / v) polyproline solution with a molecular weight of 3000~10000 using 0.1M phosphate buffer solution with pH 6.5. Then, immerse the plasma-activated silk in the polyproline solution at a bath ratio of fabric:polyproline solution = 1:20 and stir at 30 rpm for 30 minutes to obtain impregnated silk.

[0123] S6: Roll the impregnated silk under a uniform pressure of 0.3MPa and control the liquid content at 80±5%. Then, place the silk in an oven at 80℃ for pre-drying for 5 minutes. Then, raise the temperature of the oven to 130℃ and keep it warm for 4 minutes.

[0124] S7: The fabric will be subjected to fabric wrinkle recovery angle test, breaking strength test and simulated 5 household washing tests in sequence to verify the durability of wrinkle resistance.

[0125] Experimental results: See Table 5 for details.

[0126] Table 5: Test Results of Example 5

[0127] Wrinkle recovery angle test (longitude + latitude, °) Fracture strength (meridian, N) / retention rate Recovery angle retention rate after 5 washes Example 5 205 410 / 93% 78%

[0128] In this embodiment, acetylation is placed before plasma activation, which reverses the core process sequence. Mechanistically, the pre-acetylation treatment blocks a large number of amino groups on the surface of the silk fiber, which seriously hinders the efficiency of subsequent plasma treatment in activating the fiber surface and greatly reduces the reaction sites available for polyproline crosslinking. As a result, the two core steps of plasma activation and biological crosslinking cannot be carried out effectively. The resulting crosslinking network is sparse and inefficient, leading to the worst performance in all embodiments.

[0129] Comparative Example 1

[0130] This embodiment provides a traditional anti-wrinkle finishing process for silk fabrics, the specific implementation steps of which include:

[0131] Experimental materials:

[0132] 100 parts by weight of silk fabric, 2000-3000 parts by weight of deionized water, 80-120 parts by weight of dimethyloldihydroxyethylene urea resin finishing agent (solid content 40-50%), 10-15 parts by weight of magnesium chloride, 1-2 parts by weight of nonionic penetrant JFC, and 3000-5000 parts by weight of 2% (w / v) sodium bicarbonate solution.

[0133] Experimental objective:

[0134] Traditional 2D resin is used to perform anti-wrinkle finishing on silk fabrics.

[0135] Experimental steps:

[0136] S1: Place the silk fabric in a neutral soap flake solution with a bath ratio of 1:30 and scour it at 95°C for 60 minutes. Then wash the fabric thoroughly with water until it is neutral, and then dry it at 60°C.

[0137] S2: Add penetrant JFC, catalyst magnesium chloride and 2D resin sequentially to deionized water, then stir evenly to prepare a working solution. Then, perform two dips and two nips at room temperature with a bath ratio of 1:20 and control the nips ratio to 80%±5%.

[0138] S3: Pre-dry the impregnated fabric in an oven at 80°C for 5 minutes, and then bake it in a baking oven at 150°C for 3 minutes to allow the resin to undergo a full cross-linking reaction inside the fiber.

[0139] S4: Rinse the baked fabric with warm water first, then place it in a 2% sodium bicarbonate solution with a bath ratio of 1:30 to neutralize the residual acid, and finally wash it thoroughly with 50°C warm water and dry it at 70°C.

[0140] Experimental results: See Table 6 for details.

[0141] Table 6: Test Results of Comparative Example 1

[0142] Wrinkle recovery angle test (longitude + latitude, °) Fracture strength (meridian, N) / retention rate Recovery angle retention rate after 5 washes Comparative Example 1 275 350 / 80% 88%

[0143] This comparative example uses the traditional dihydroxymethyl dihydroxyvinyl urea chemical finishing process. Mechanistically, under the action of a catalyst, the 2D resin undergoes covalent cross-linking with the hydroxyl and amino groups on the fiber macromolecules, forming a rigid three-dimensional network inside the fiber. Although this strong covalent bond can provide good initial wrinkle resistance and certain wash resistance, the covalent cross-linking irreversibly destroys the fiber's own flexibility and molecular chain slippage ability, resulting in a severe loss of breaking strength of only 80%. In addition, covalent cross-linking is usually accompanied by formaldehyde release.

[0144] Example 1 employs a standard complete process from 80W plasma activation to polyproline crosslinking and then acetylation reinforcement, achieving an optimal balance among wrinkle resistance, strength retention, and washability. Through the synergistic effect of physical activation, bio-spiral crosslinking, and chemical reinforcement, it significantly improves the elastic recovery ability of the fabric and the durability of the finishing effect, making it suitable for producing high-end, environmentally friendly silk products that require high shape retention.

[0145] Example 2 showed that insufficient plasma treatment intensity led to inadequate fiber surface activation, resulting in a maximum tensile strength retention rate of 97%. However, the degree of polyproline crosslinking was limited, and the initial wrinkle resistance of 235° and the post-wash retention rate of 85% were significantly lower than those in Example 1, demonstrating that 80W and a treatment time of 5 minutes are necessary activation conditions.

[0146] Example 3 uses linear polylysine to replace polyproline with a rigid type II helical structure. However, the constructed cross-linked network has insufficient three-dimensional structure and elasticity, resulting in a wrinkle resistance of 250° and a wash resistance of 82%, which are both lower than those of Example 1. This demonstrates the irreplaceable role of the unique helical structure of polyproline in forming an elastic cross-linked network.

[0147] Example 4 uses a process that omits the acetylation step, but the unreacted amino groups are prone to reforming hydrogen bonds during the washing process, causing the wrinkle resistance retention rate to drop sharply to 75% after 5 washes. Although the initial wrinkle resistance of 270° and strength of 99% are still acceptable, this proves that acetylation plays a key role in wrinkle resistance and improving durability.

[0148] Example 5 uses a process that reverses the acetylation-activation-crosslinking sequence. However, the amino group is blocked by acetylation first, which seriously hinders the efficiency of subsequent plasma activation and effective crosslinking of polyproline. As a result, the performance is the worst among all examples, with a wrinkle resistance angle of only 205°. This proves the scientific nature and necessity of the activation → crosslinking → reinforcement sequence.

[0149] Comparative Example 1, using a traditional 2D resin chemical crosslinking process, achieved an initial wrinkle resistance of 275°, but its breaking strength retention rate was only 80%. This indicates that the chemical crosslinking agent forms a rigid covalent crosslinking network within the fiber, leading to decreased fiber flexibility and a risk of formaldehyde release, which does not meet environmental protection requirements. Its wash resistance of 88% is acceptable, but its overall performance and safety are inferior to the physical-biological synergistic finishing system provided by this invention.

[0150] refer to Figure 1 The flowchart visually illustrates the complete process and logical structure of the environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics described in this invention. The process starts with pre-cleaning and sequentially goes through core steps such as low-temperature plasma activation, polyproline impregnation and cross-linking, rolling and pre-drying, acetylation treatment, neutralization and soaping, and dehydration and drying. Finally, the finishing effect is verified through performance testing. The flowchart clearly shows the main process line of physical activation, biological cross-linking, and chemical stabilization working together, as well as the sequential relationship between each step, material flow, and key control links.

[0151] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of protection of the claims.

[0152] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics, characterized in that, Specifically, the following steps are included: S1: Soak the silk in a neutral soap flake solution and heat it. Then, wash the treated silk thoroughly in warm water. Finally, dry the washed silk in an oven to obtain pre-cleaned silk. S2: The pre-cleaned silk obtained in S1 is placed in a radio frequency glow discharge low-temperature plasma device and the silk is laid flat on the electrodes of the processing chamber and the chamber is sealed. After the reaction is completed, plasma-activated silk is obtained. S3: Prepare a polyproline solution using phosphate buffer, then immerse the plasma-activated silk in the polyproline solution at a ratio of 1:20 of silk to polyproline solution and stir at 30 rpm for 30 minutes to obtain impregnated silk. S4: Roll the impregnated silk and control the liquid content, then place the silk in an oven for pre-drying, then raise the temperature of the oven and keep it warm; S5: Acetic anhydride and glacial acetic acid are mixed to prepare an acetylation treatment solution. The silkworms baked in S4 are then immersed in the acetylation treatment solution and then placed in a constant temperature water bath for heat preservation. S6: Rinse the silk treated in S5 with cold water, then soak the silk in sodium bicarbonate solution at a bath ratio of 1:30, then soap the silk in a neutral soap flake solution, and finally wash the silk with warm water. S7: Place the silk washed with warm water in S6 into a centrifugal dehydrator at 1000 rpm for 3 minutes to dehydrate, and then spread the dehydrated silk out in a forced-air drying oven at 70℃ to dry to constant weight. S8: The silk was subjected to fabric wrinkle recovery angle test, breaking strength test, and simulated 5 household washing tests in sequence to verify the durability of the wrinkle resistance effect.

2. The environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics as described in claim 1, characterized in that, In step S1, the silk fabric is soaked in a neutral soap flake solution at a bath ratio of 1:30 to 1:50, and then the solution is heated to 95 to 100°C and kept warm for 60 minutes.

3. The environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics as described in claim 1, characterized in that, In step S1, the treated silk is washed thoroughly in warm water at 35-40℃ for 5 minutes, and finally dried in an oven at a relative humidity of 65±4% and a temperature of 60℃ for 24 hours.

4. The environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics as described in claim 1, characterized in that, In S2, the operating power of the low-temperature plasma device is set to 80W, the cavity gas is oxygen, the cavity pressure is 30~50Pa, and the operating time is 5 minutes.

5. The environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics as described in claim 1, characterized in that, The phosphate buffer used in S3 is a 0.1M pH 6.5 buffer, which is then mixed with polyproline with a molecular weight of 3000~10000 to prepare a 1.0~2.0% (w / v) solution.

6. The environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics as described in claim 1, characterized in that, In step S4, the impregnated silk is rolled under a uniform pressure of 0.3~0.5MPa and the liquid retention rate of the silk is controlled to reach 80±5%. Then, the silk is placed in an oven at 80℃ for pre-drying for 5~10 minutes. Finally, the temperature inside the oven is raised to 130℃ and dried for 4~5 minutes.

7. The environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics as described in claim 1, characterized in that, In S5, acetic anhydride and glacial acetic acid are uniformly mixed in a volume ratio of 1:4 to obtain an acetylation treatment solution.

8. The environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics as described in claim 1, characterized in that, In S5, the baked silk is thoroughly soaked in the acetylation treatment solution at a bath ratio of 1:5, and then the mixture is placed in a constant temperature water bath at 60°C for 60 minutes.

9. The environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics as described in claim 1, characterized in that, In step S6, the acetylated silk is first rinsed with water at 10-15°C for 10 minutes, then soaked in a sodium bicarbonate solution with a concentration of 1-2% (w / v) at a bath ratio of 1:30 for 15 minutes, then soaped in a neutral soap flake solution at 60°C with a concentration of 1-1.2 g / L for 10-15 minutes, and finally washed with warm water at 50±2°C.

10. The environmentally friendly low-temperature plasma anti-wrinkle finishing process for silk fabrics as described in claim 1, characterized in that, In S7, the silk washed with warm water is placed in a centrifugal dehydrator at 1000~1500rpm for 3~5 minutes to dehydrate. Finally, the dehydrated silk is laid flat in a forced-air drying oven at 70℃ and dried to constant weight.

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