Polylactic acid fabric and preparation method thereof

Abstract

The invention relates to the field of textile fabrics, and discloses a polylactic acid fabric and a preparation method thereof. The polylactic acid fabric is prepared by weaving polylactic acid fibers, the polylactic acid fibers are prepared by melt spinning of a polylactic acid material body, and the polylactic acid material body is prepared from the following raw materials in parts by weight: 100-120 parts of polylactic acid resin, 12-20 parts of a heat-resistant moisture absorbent, 6-10 parts of a toughening agent and 0.2-0.4 part of an antioxidant; the heat-resistant moisture absorbent is prepared from lignin fibers, poly (ethylene 2, 5-furandicarboxylate), poly (butylene adipate-co-terephthalate) and a dispersing agent. The preparation method comprises the following steps of melt spinning, rib knitting, heat setting, dyeing and aftertreatment. The polylactic acid fabric prepared by the invention has better heat resistance, moisture absorption and shrink deformation resistance, and is suitable for scenes with higher requirements on heat resistance and moisture absorption, such as underwear or infant clothes.

Description

Technical Field

[0001] This application relates to the field of textile fabrics, and in particular to a polylactic acid fabric and a method for preparing the same. Background Technology

[0002] Polylactic acid (PLA) fabric is a green and renewable aliphatic polyester fiber, usually made by weaving PLA fibers. PLA fibers are made by melt spinning PLA resin, and have good biodegradability and environmental protection. They also have the advantages of soft hand feel, smooth and breathable texture and good drape, and are widely used in the clothing industry.

[0003] However, when polylactic acid (PLA) fabrics are used in scenarios where heat resistance and moisture absorption are required, such as underwear or infant clothing, these garments are usually worn close to the skin and need to have good sweat absorption and heat resistance. They also need to be washed frequently. After multiple washes, the garments will inevitably experience problems such as deformation and shrinkage, which reduces the applicability of PLA fabrics in scenarios such as underwear or infant clothing.

[0004] In existing technologies, to improve the moisture absorption, heat resistance, and shrinkage resistance of polylactic acid (PLA) fabrics, PLA fibers are typically blended with modal fibers, bamboo fibers, flax fibers, etc., during the manufacturing process to create blended yarns. While this can improve the PLA fabric to some extent, the glass transition temperature of PLA fibers is low, generally 55-60℃. Therefore, the subsequent setting and heat treatment temperatures generally cannot exceed 130℃, otherwise the fabric is prone to softening and shrinkage. Other fibers, on the other hand, require high-temperature setting, generally around 180℃. This reduces the heat setting efficiency of the blended PLA fabric, resulting in PLA fabrics that still suffer from low moisture absorption, heat resistance, and shrinkage resistance when used in long-term washing and humid environments. Summary of the Invention

[0005] To address the issues of low moisture absorption, heat resistance, and shrinkage resistance in existing polylactic acid (PLA) fabrics used in long-term washing and humid environments, this application provides a PLA fabric and its preparation method.

[0006] In a first aspect, this application provides a polylactic acid fabric, which adopts the following technical solution: A polylactic acid (PLA) fabric is made by weaving PLA fibers, wherein the PLA fibers are made by melt spinning PLA stock, and the PLA stock is made from the following raw materials in parts by weight: 100-120 parts of polylactic acid resin 12-20 parts of heat-resistant moisture absorbent 6-10 parts toughening agent Antioxidant 0.2-0.4 parts; the heat-resistant and moisture-absorbing agent is prepared from lignin fiber, polyethylene 2,5-furandicarboxylate, polybutylene terephthalate-adipate and dispersant.

[0007] By adopting the above technical solutions, polylactic acid resin, as the basic raw material, endows the fabric with good biodegradability and environmental friendliness, resulting in a soft, smooth, breathable, and well-draping feel. The heat-resistant and moisture-wicking agent, made from lignin fiber, polyethylene 2,5-furandicarboxylate, polybutylene terephthalate-adipate, and a dispersant, effectively improves the fabric's heat resistance and moisture absorption. The toughening agent enhances the fabric's resilience and reduces deformation. The antioxidant prevents fabric oxidation. The synergistic effect of polylactic acid resin, the heat-resistant and moisture-wicking agent, and the toughening agent gives the resulting polylactic acid fabric good heat resistance, moisture absorption, and shrinkage resistance, making it suitable for applications requiring high heat resistance and moisture absorption, such as underwear or infant clothing.

[0008] Preferably, the heat-resistant hygroscopic agent is prepared from the following raw materials in parts by weight: 20-30 parts of lignin fiber 45-55 parts of polyethylene 2,5-furandicarboxylate 7-12 parts of polybutylene terephthalate (PET) Dispersant 7-14 parts.

[0009] By adopting the above technical solutions, lignin fiber, with its excellent moisture absorption and biocompatibility, enhances the sweat-wicking properties of polylactic acid (PLA) fabrics, making them more comfortable. Polyethylene 2,5-furandicarboxylate possesses high flexibility and mechanical properties, enhancing the heat resistance and elasticity of PLA fabrics and preventing softening and shrinkage at high temperatures. Polybutylene terephthalate (PET) exhibits good heat resistance and processing performance, helping to improve the elasticity and processing characteristics of PLA fabrics, making them less prone to deformation. The dispersant ensures uniform dispersion of the raw materials, improving the performance stability of the heat-resistant moisture-wicking agent. When applied to PLA fabrics, the resulting heat-resistant moisture-wicking agent significantly improves the fabric's heat resistance, moisture absorption, and shrinkage resistance.

[0010] Preferably, the dispersant is composed of a long-chain alkyl silane coupling agent and pentaerythritol triallyl ether in a weight ratio of 1:(2-4).

[0011] By adopting the above technical solution, long-chain alkylsilane coupling agents and pentaerythritol triallyl ether can achieve a good synergistic effect, enabling lignin fibers, polyethylene 2,5-furandicarboxylate, and polybutylene terephthalate to be uniformly dispersed during the preparation process, improving the compatibility and dispersion performance of the heat-resistant and moisture-absorbing agent. This, in turn, allows the heat-resistant and moisture-absorbing agent to function better, enhancing the heat resistance and moisture absorption of polylactic acid fabrics, while also helping to strengthen the fabric's resistance to shrinkage and deformation. The long-chain alkylsilane coupling agent can be a dodecyl to octadecylsilane coupling agent, which has good flexibility and dispersion uniformity.

[0012] Preferably, the heat-resistant moisture-absorbing agent is prepared by the following steps: melt extruding lignin fiber, polyethylene 2,5-furandicarboxylate, polybutylene terephthalate-adipate and dispersant, cooling, and pelletizing to obtain the heat-resistant moisture-absorbing agent.

[0013] By adopting the above technical solution, the raw materials can be thoroughly and uniformly mixed, ensuring the stable and consistent performance of the resulting heat-resistant hygroscopic agent. This uniform mixing helps the heat-resistant hygroscopic agent better exert its moisture-absorbing and heat-resistant functions, improving the moisture absorption and heat resistance of polylactic acid fabrics. Subsequent cooling and pelletizing facilitates further mixing of the heat-resistant hygroscopic agent with other raw materials.

[0014] Preferably, the melt extrusion temperature is 200-220℃.

[0015] By adopting the above technical solution, this temperature range allows lignin fiber, polyethylene 2,5-furandicarboxylate, polybutylene terephthalate-adipate, and dispersant to be fully melted and mixed, ensuring uniform dispersion of each raw material, thereby making the heat-resistant and moisture-absorbing agent more stable.

[0016] Preferably, the toughening agent is composed of diglycidyl cyclohexane-1,2-dicarboxylic acid and castor oil in a weight ratio of 1:(1-2).

[0017] By adopting the above technical solutions, the flexibility and resilience of polylactic acid (PLA) fabrics can be significantly improved. Specifically, cyclohexane-1,2-dicarboxylic acid diglycidyl ester possesses excellent flexibility, can interweave and disperse with PLA molecular chains, and enhances the interaction between molecular chains, thereby improving the fabric's toughness. Castor oil has lubricating and plasticizing effects, which can reduce the friction between PLA molecular chains, making the molecular chains easier to slide, thus improving the fabric's flexibility and resilience, making PLA fabrics less prone to breakage and deformation during use.

[0018] Preferably, the antioxidant is antioxidant 1010 and / or antioxidant 168.

[0019] By adopting the above technical solutions, antioxidant 1010 and / or antioxidant 168 can effectively inhibit the oxidation reaction of polylactic acid fabric during processing and use, prevent polylactic acid resin from degrading due to oxidation, maintain the performance stability of polylactic acid fabric, extend its service life, and thus improve the quality and applicability of polylactic acid fabric in long-term washing and humid heat environments.

[0020] Preferably, the polylactic acid fiber has a specification of 20-30D.

[0021] By adopting the above technical solutions, polylactic acid fibers with a finer texture can make the resulting polylactic acid fabrics softer and more delicate to the touch, providing a better feel against the skin and improving wearing comfort. At the same time, the fiber of this specification further enhances the breathability of the fabric, making it better suited for scenarios with high requirements for heat resistance and moisture absorption, such as underwear or infant clothing. It can also make the fabric drape better and have a more beautiful appearance.

[0022] Secondly, this application provides a method for preparing polylactic acid fabric, which adopts the following technical solution: A method for preparing polylactic acid fabric includes the following steps: S1. Polylactic acid material is melt-spun to obtain polylactic acid fiber; S2. Polylactic acid fibers are knitted in rib pattern to obtain a semi-finished polylactic acid fabric. S3. Heat setting, dyeing, and post-treatment of polylactic acid fabric semi-finished products are carried out to obtain polylactic acid fabric.

[0023] By adopting the above technical solution, in step S1, polylactic acid (PLA) material made from PLA resin, heat-resistant hygroscopic agent, toughening agent, and antioxidant is melt-spun to obtain PLA fiber. The heat-resistant hygroscopic agent can give PLA fiber good heat resistance and moisture absorption, the toughening agent can enhance fiber toughness, and the antioxidant can improve fiber antioxidant capacity. In step S2, PLA fiber is rib-knitted to obtain PLA fabric semi-finished product. Rib knitting helps to ensure the elasticity and stability of the fabric. In step S3, PLA fabric semi-finished product is heat-set, dyed, and post-treated to obtain PLA fabric. Heat setting makes the fabric structure more stable and reduces deformation and shrinkage during subsequent use. Dyeing and post-treatment allow the fabric to meet different use and appearance requirements. The final PLA fabric has good heat resistance, moisture absorption, and shrinkage resistance, and is suitable for occasions with high requirements for heat resistance and moisture absorption, such as underwear or infant clothing.

[0024] Preferably, the melt spinning temperature in step S1 is 170-200℃.

[0025] By adopting the above technical solution, the polylactic acid material is fully melted, resulting in higher quality polylactic acid fibers, which in turn improves the heat resistance, moisture absorption, and shrinkage resistance of polylactic acid fabrics.

[0026] In summary, this application includes at least one of the following beneficial technical effects: 1. The polylactic acid fabric of this application is made by mixing heat-resistant moisture-absorbing agent, toughening agent and antioxidant with polylactic acid resin to form polylactic acid material, and then spinning and weaving it into polylactic acid fabric. This makes the polylactic acid fabric have good heat resistance, moisture absorption and shrinkage and deformation resistance in long-term washing and humid environments, and is suitable for close-fitting clothing or infant clothing with high requirements for heat resistance and moisture absorption.

[0027] 2. The heat-resistant and moisture-absorbing agent is made from lignin fiber, polyethylene 2,5-furandicarboxylate, polybutylene terephthalate (PET), and a dispersant. Lignin fiber itself has a certain degree of moisture absorption, which can improve the moisture absorption performance of the fabric; polyethylene 2,5-furandicarboxylate and PET help enhance the heat resistance and flexibility of the fabric. Together, they give the resulting polylactic acid fabric good elasticity, moisture absorption, and heat resistance.

[0028] 3. The dispersant consists of a long-chain alkyl silane coupling agent and pentaerythritol triallyl ether. The combination of these two components ensures uniform dispersion of the heat-resistant and moisture-wicking agent, thereby improving the performance of the polylactic acid fabric and enhancing its resistance to shrinkage and deformation.

[0029] 4. The toughening agent is composed of cyclohexane-1,2-dicarboxylic acid diglycidyl ester and castor oil. The two work synergistically to enhance the toughness of polylactic acid fabric and further improve its shrinkage and deformation resistance.

[0030] 5. The preparation process involves first melt spinning polylactic acid (PLA) material to obtain PLA fibers, then knitting the PLA fibers in rib knit to obtain PLA fabric semi-finished products, and finally heat setting, dyeing, and post-treatment of the semi-finished products. This process ensures the proper formation of PLA fibers while avoiding fabric softening and shrinkage due to excessively high temperatures, thus improving the quality and performance of PLA fabrics. Detailed Implementation

[0031] The present application will be further described in detail below with reference to the embodiments.

[0032] The following are some of the sources and specifications of the raw materials used in this application. The raw materials used in the preparation examples and embodiments of this application can all be obtained commercially, including but not limited to the following models and manufacturers of raw materials. Raw materials with equivalent performance can also be used: 1. Polylactic acid resin: Fengyuan FY602; 2. Polyethylene 2,5-furandicarboxylate: Wuhan Kemic, CAS No. 28728-19-0, content 98%; 3. Polybutylene terephthalate (PBAT): Shuer PBAT resin, CAS No. 55231-08-8, content 99%; 4. Lignin fiber: diameter 35-80μm, length 0.14-0.5mm, elongation at break ≥470Mpa, decomposition rate less than 5% at 250℃.

[0033] Preparation example of heat-resistant desiccant Preparation Example 1 Preparation Example 1 discloses a heat-resistant hygroscopic agent, which is prepared by the following steps: 2 kg of lignin fiber, 4.5 kg of polyethylene 2,5-furandicarboxylate, 0.7 kg of polybutylene terephthalate-adipate, and 0.7 kg of dodecyltrimethoxysilane are used as dispersants and melt extruded using a twin-screw extruder. The melt extrusion temperatures are as follows: Zone 1 200℃, Zone 2 205℃, Zone 3 215℃, Zone 4 220℃, Zone 5 215℃, and Die 210℃. After water cooling, the product is pelletized to obtain the heat-resistant hygroscopic agent.

[0034] Preparation Examples 2-3 The difference between Preparation Example 2-3 and Preparation Example 1 lies in the amount of raw materials used and the preparation conditions, as detailed in Table 1 below.

[0035] Table 1. Parameters for Preparation Examples 1-3

[0036] Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 3 is that the dispersant is composed of dodecyltrimethoxysilane and pentaerythritol triallyl ether in a weight ratio of 1:2, while the rest is the same as Preparation Example 3.

[0037] Preparation Example 5 The difference between Preparation Example 5 and Preparation Example 4 is that the dispersant is composed of dodecyltrimethoxysilane and pentaerythritol triallyl ether in a weight ratio of 1:4, while the rest is the same as Preparation Example 4.

[0038] Preparation of Comparative Example 1 The difference between Comparative Example 1 and Preparation Example 3 is that polybutylene terephthalate-adipate was replaced with polyethylene 2,5-furandicarboxylate in equal amounts; otherwise, they were the same as in Preparation Example 3.

[0039] Preparation of Comparative Example 2 The difference between Comparative Example 2 and Preparation Example 3 is that polyethylene 2,5-furandicarboxylate was replaced with polybutylene terephthalate in equal amounts, while the rest was the same as Preparation Example 3.

[0040] Preparation of Comparative Example 3 The difference between Comparative Example 3 and Preparation Example 3 is that lignin fiber was replaced with seaweed fiber in equal amounts, while the rest was the same as Preparation Example 3.

[0041] Preparation of Comparative Example 4 The difference between Comparative Example 4 and Preparation Example 4 is that the dispersant was replaced with polyethylene 2,5-furandicarboxylate in equal amounts; otherwise, they were the same as Preparation Example 4. Example Example 1

[0042] Example 1 discloses a polylactic acid fabric, which is prepared by the following steps: S1. Polylactic acid (PLA) material was melt-spun using a melt spinning machine at a melting temperature of 170°C and a spinning temperature of 200°C to obtain PLA fibers with a specification of 20D. The PLA material was prepared from 10 kg PLA fibers, 1.2 kg of the heat-resistant and moisture-absorbing agent prepared in Preparation Example 1, 0.6 kg of castor oil as a toughening agent, and 0.02 kg of antioxidant (the antioxidant consisted of antioxidant 1010 and antioxidant 168 in a weight ratio of 1:1). S2. Using a weft knitting machine, polylactic acid fibers are knitted in a 1*1 rib pattern to obtain a semi-finished polylactic acid fabric with a weight of 160g / m². 2 ; S3. The polylactic acid fabric semi-finished product is subjected to hot air setting, dyeing, softening treatment, washing and drying at a temperature of 100℃ to obtain polylactic acid fabric; among which, dyeing and softening treatment are conventional processes in this field and will not be described in detail here.

[0043] Example 2-3 The difference between Examples 2-3 and Example 1 lies in the amount of raw materials and the preparation conditions; all other aspects are the same as in Example 1. See Table 2 below for details.

[0044] Table 2 Parameter Table for Examples 1-3

[0045] Example 4

[0046] The difference between Example 4 and Example 3 is that the heat-resistant hygroscopic agent is derived from Preparation Example 4, while the rest is the same as in Example 3.

[0047] Example 5

[0048] The difference between Example 5 and Example 3 is that the heat-resistant hygroscopic agent is derived from Preparation Example 5, while the rest is the same as in Example 3.

[0049] Example 6

[0050] The difference between Example 6 and Example 4 is that the toughening agent is composed of diglycidyl cyclohexane-1,2-dicarboxylic acid and castor oil in a weight ratio of 1:1, and the rest is the same as in Example 4.

[0051] Example 7

[0052] The difference between Example 7 and Example 4 is that the toughening agent is composed of cyclohexane-1,2-dicarboxylic acid diglycidyl ester and castor oil in a weight ratio of 2:1, while the rest is the same as in Example 4.

[0053] Comparative Example

[0054] Comparative Examples 1-4 The difference between Comparative Examples 1-4 and Example 3 is that the sources of the heat-resistant hygroscopic agents are different, as detailed in Table 3 below.

[0055] Table 3. Sources of the heat-resistant hygroscopic agents used in Comparative Examples 1-4 Performance testing

[0056] The following tests were conducted on the performance of the polylactic acid fabrics prepared in Examples 1-7 and Comparative Examples 1-4: 1. Hygroscopicity test According to the test method in GB / T 21655.2-2019, test the water absorption rate A (unit: % / s), and record the test results.

[0057] 2. Heat resistance test Place a 5*10cm polylactic acid fabric in a constant temperature and humidity chamber at 45℃ and 85% humidity for 7 days, then remove it. Use a tensile testing machine to stretch it to 1.5 times its length, hold for 30 seconds, and then allow it to recover. Repeat this stretching test for 30 seconds. After 25 cycles, test the deformation rate (unit: %). Deformation rate = |length after test - length before test| / length before test * 100%. Test and record the results.

[0058] 3. Water wash resistance test: Place a 5*10cm polylactic acid fabric in the test washing machine, adjust to the quick wash mode (wash + dry for 15 minutes), add 1wt% commercial laundry detergent, and wash 25 times. After washing, air dry and test the length deformation rate (unit: %). Deformation rate = |length after test - length before test| / length before test * 100%. Test and record the test results.

[0059] The following are the performance test data of the polylactic acid fabrics prepared in Examples 1-7 and Comparative Examples 1-4, as detailed in Table 4 below.

[0060] Table 4 Performance data of polylactic acid fabrics in Examples 1-7 and Comparative Examples 1-4

[0061] The data table above shows that: Compared to Example 3, Examples 4-5 further optimized the components and proportions of the heat-resistant hygroscopic agent, resulting in increased water absorption rate and reduced heat resistance and washing deformation rate of the polylactic acid fabric. Comparative Examples 1-4, compared to Example 3, changed the types and proportions of lignin fiber, polyethylene 2,5-furandicarboxylate, polybutylene terephthalate-adipate, and dispersant in the heat-resistant hygroscopic agent, significantly reducing the water absorption rate of the polylactic acid fabric and significantly increasing the deformation rate after heat resistance and washing tests. This demonstrates that the heat-resistant hygroscopic agent of this application can significantly improve the heat resistance, moisture absorption, and shrinkage resistance of the resulting polylactic acid fabric.

[0062] Compared to Example 4, Examples 6-7 further optimized the type and ratio of toughening agents, resulting in increased water absorption rate of the polylactic acid fabric and reduced heat resistance and washing deformation rate. This indicates that the toughening agent of this application can further enhance the flexibility and elasticity of polylactic acid fibers, thereby reducing the deformation rate of the polylactic acid fabric and slightly increasing the water absorption rate of the polylactic acid fabric.

[0063] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A polylactic acid fabric, characterized in that, It is made of polylactic acid (PLA) fibers through weaving, wherein the PLA fibers are produced by melt spinning of PLA material, and the PLA material is obtained from the following raw materials in parts by weight: 100-120 parts of polylactic acid resin 12-20 parts of heat-resistant moisture absorbent 6-10 parts toughening agent Antioxidant 0.2-0.4 parts; the heat-resistant and moisture-absorbing agent is prepared from lignin fiber, polyethylene 2,5-furandicarboxylate, polybutylene terephthalate-adipate and dispersant.

2. The polylactic acid fabric according to claim 1, characterized in that, The heat-resistant hygroscopic agent is prepared from the following raw materials in parts by weight: 20-30 parts of lignin fiber 45-55 parts of polyethylene 2,5-furandicarboxylate 7-12 parts of polybutylene terephthalate (PET) Dispersant 7-14 parts.

3. The polylactic acid fabric according to claim 2, characterized in that, The dispersant is composed of a long-chain alkyl silane coupling agent and pentaerythritol triallyl ether in a weight ratio of 1:(2-4).

4. A polylactic acid fabric according to any one of claims 1-3, characterized in that, The heat-resistant moisture absorbent is prepared by the following steps: lignin fiber, polyethylene 2,5-furandicarboxylate, polybutylene terephthalate-adipate and dispersant are melt-extruded, cooled, and pelletized to obtain the heat-resistant moisture absorbent.

5. A polylactic acid fabric according to claim 4, characterized in that, The melt extrusion temperature is 200-220℃.

6. The polylactic acid fabric according to claim 1, characterized in that, The toughening agent is composed of diglycidyl cyclohexane-1,2-dicarboxylic acid and castor oil in a weight ratio of 1:(1-2).

7. The polylactic acid fabric according to claim 1, characterized in that, The antioxidant is antioxidant 1010 and / or antioxidant 168.

8. The polylactic acid fabric according to claim 1, characterized in that, The polylactic acid fiber has a specification of 20-30D.

9. A method for preparing a polylactic acid fabric as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Polylactic acid material is melt-spun to obtain polylactic acid fiber; S2. Polylactic acid fibers are knitted in rib pattern to obtain a semi-finished polylactic acid fabric. S3. Heat setting, dyeing, and post-treatment of polylactic acid fabric semi-finished products are carried out to obtain polylactic acid fabric.

10. The method for preparing polylactic acid fabric according to claim 9, characterized in that, The melt spinning temperature in step S1 is 170-200℃.

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