Bio-based PA510 brocade spandex fabric and preparation method thereof

Abstract

The application discloses a bio-based PA510 brocade spandex four-way stretch fabric and a preparation method thereof. The bio-based PA510 brocade spandex four-way stretch fabric is mainly formed by interweaving warp yarns and weft yarns. The warp yarns are covered yarn structure yarns formed by taking bio-based PA510 yarns as outer wrapping fibers and spandex as core filaments. The weft yarns include weft yarn A and weft yarn B. The weft yarn A is a twisted yarn formed by plying and twisting at least two bio-based PA510 yarns. The weft yarn B is a covered yarn structure yarn formed by taking bio-based PA510 yarns as outer wrapping fibers and spandex as core filaments. The application develops a fabric with high bio-based content, accurate 70D yarn gauge specification, excellent four-way stretch performance, stable physical indexes and safe environmental protection by optimizing the combination design of brocade spandex yarns, jacquard structure and weaving, dyeing and finishing processes, meets the market demand of downstream fields for green and high-performance elastic fabrics, and promotes the industrial application of bio-based polyamide materials in the field of textile elastic fabrics.

Description

Technical Field

[0001] This invention belongs to the field of textile fabric technology, and particularly relates to a bio-based PA510 nylon-spandex four-way stretch fabric and its preparation method. Background Technology

[0002] Against the backdrop of the textile industry's transformation towards green, low-carbon, and high-performance manufacturing, traditional petroleum-based polyamide (PA) fabrics are increasingly unable to meet environmental policy requirements and market demands for green consumption due to their reliance on fossil resources, high carbon emissions from production, and poor biodegradability. Meanwhile, downstream sectors such as apparel, home textiles, and sportswear are experiencing a continuous rise in demand for nylon-spandex four-way stretch fabrics. These fabrics require excellent physical properties such as bidirectional elasticity, elastic recovery, and tensile strength, while also demanding higher standards for yarn count precision (e.g., 70D), wearing comfort, and dimensional stability. Existing conventional nylon-spandex fabrics suffer from drawbacks such as low bio-based content, poor elasticity-strength compatibility, and difficulty in controlling dimensional changes after washing, making it difficult to balance environmental attributes with high-performance indicators.

[0003] Bio-based PA510, as a novel green polyamide material, uses bio-based pentanediamine as its core raw material and can effectively replace petroleum-based PA6 and PA66. Its high bio-based content and low carbon emissions align with the trend of green upgrading in textile materials. Furthermore, it possesses good mechanical properties, heat resistance, and weaving adaptability, making it a high-quality raw material for developing environmentally friendly, high-performance elastic fabrics. However, bio-based PA510 fabrics also present challenges in achieving optimal performance during the weaving process.

[0004] Therefore, the following problems still exist in the existing technology: 1) Traditional nylon-spandex four-way stretch fabrics rely on petroleum-based polyamide raw materials, have low bio-based content, cannot meet the green and environmentally friendly requirements of the textile industry's transformation, and suffer from the pain points of high fossil resource consumption and high carbon emissions in production. 2) Existing bio-based polyamide materials have technical problems in spinning 70D medium-fine denier nylon-spandex yarn, such as poor spinning formability, insufficient yarn strength, and low compatibility with spandex loose-wrap composite, making it difficult to prepare 70D bio-based nylon-spandex elastic yarn that meets the process requirements. 3) Conventional nylon-spandex four-way stretch fabrics are prone to problems such as large difference in elasticity between warp and weft, low elastic recovery rate, and severe dimensional deformation after washing, and cannot meet the dual performance requirements of bi-directional tensile strength and excellent dimensional stability. 4) During the weaving process, bio-based PA510 fabrics have technical bottlenecks such as poor compatibility with small jacquard structures, low fabric smoothness, and difficulty in balancing tensile strength and elasticity, making it difficult to achieve a balance between high bio-based content and fabric tensile strength. 5) Existing green elastic fabrics generally suffer from a mismatch between safety performance and process stability. Some products cannot simultaneously meet all the requirements of the GB 18401 safety standard and the FZ / T 14048-2020 industry standard, making industrial application difficult. Summary of the Invention

[0005] Purpose of the invention: To address the problems existing in the prior art, this invention provides a bio-based PA510 nylon-spandex four-way stretch fabric and its preparation method.

[0006] Technical solution: To achieve the above-mentioned objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a bio-based PA510 nylon-spandex four-way stretch fabric, wherein the bio-based PA510 nylon-spandex four-way stretch fabric is mainly composed of interwoven warp and weft yarns: The warp yarn is a covered yarn structure formed by using bio-based PA510 yarn as the outer fiber and spandex as the core yarn; The weft yarn includes weft yarn A and weft yarn B. Weft yarn A is a twisted yarn formed by twisting together at least two bio-based PA510 yarns. Weft yarn B is a covered yarn structure formed by using bio-based PA510 yarn as the outer fiber and spandex as the core yarn.

[0007] As a specific implementation scheme, the fabric has a composite structure with jacquard texture on the front and floating dot structure on the back.

[0008] As a specific implementation scheme, the bio-based PA510 yarns constituting the warp yarn, weft yarn A, and weft yarn B are all bio-based PA510 DTY 70D / 68F matte yarns; the spandex in the warp yarn and weft yarn B are all selected from spandex filament 40D / 34F.

[0009] As a specific implementation scheme, the weft yarn A is made by plying four bio-based PA510 yarns together and adding an S-twist, with a twist of 220-260 twists / meter.

[0010] As a specific implementation scheme, the weft yarns A and B are arranged alternately in the fabric at a ratio of 1:(0.9-1.1); the warp density of the fabric is 150-165 threads / inch, and the weft density is 140-150 threads / inch.

[0011] Secondly, the present invention provides a method for preparing the above-mentioned bio-based PA510 nylon-spandex four-way stretch fabric, comprising the following steps: (1) Yarn preparation: Prepare warp yarn, weft yarn A and weft yarn B; (2) Weaving: The prepared warp yarns and weft yarns A and B are woven on a loom to form a greige fabric with a jacquard texture on the surface and a dotted structure on the back. (3) Dyeing and finishing: The obtained greige fabric is subjected to flat cold piling pretreatment, pre-setting, dyeing, color fixing, drying and high temperature setting in sequence to obtain the finished fabric.

[0012] As a specific implementation plan, in step (2), the loom is equipped with an electronic shedding mechanism, a separate reed seat for weft insertion, a conjugate weft insertion mechanism, an electronic take-up mechanism, and an electronic warp feeding mechanism.

[0013] As a specific implementation plan, in step (3), the dyeing adopts a one-step dyeing process, including: placing the pre-shaped blank in a dyeing solution containing acidic matting dye and auxiliaries, controlling the bath ratio to 1:(16-20), the pH value to 4.5-5.5, and slowly raising the temperature from room temperature to 85-90℃ at a heating rate of 3-6℃ every 5 minutes, and dyeing at this temperature for 50-70 minutes.

[0014] As a further embodiment, the acid matting dyes include acid matting black, acid matting blue, and acid matting gray; the auxiliaries include ammonium sulfate, glacial acetic acid, and acid leveling agents.

[0015] As a specific implementation plan, in step (3): In the pretreatment of the flat-width cold stack, the treatment solution used includes an alkaline reducing agent, an ion-exchange membrane alkali, an oxidizing desizing agent, and a refining agent, and the stacking time is 40-50 hours; The predetermined process parameters are: speed 25-30m / min, temperature 115-126℃, and time 30-40s.

[0016] The process parameters for high-temperature setting are: speed 20-25m / min, temperature 128-136℃, and time 40-50s.

[0017] This invention has the following key innovative features: 1. Specific yarn formulation combinations based on bio-based PA510 The core of this invention lies in completely replacing petroleum-based nylon with bio-based PA510 and designing an innovative yarn system. The warp yarn is a bio-based PA510 DTY 70D / 68F covered spandex yarn; the weft yarn adopts a dual structure of "covered yarn + twisted yarn," that is, weft yarn A consists of 4 yarns of the same specification with an S-twist (240T / M), and weft yarn B is the covered yarn. This specific yarn configuration is key to achieving high bio-based content and a fine 70D specification, and directly lays the foundation for the fabric's excellent elasticity, thus ensuring that the finished product has both a good hand feel and excellent elasticity.

[0018] 2. The "small jacquard-float" composite weave structure, through precise weaving design, creates a jacquard texture on the front and a float structure on the back of the fabric. This structure not only gives the fabric a unique appearance and feel, but also ensures that the fabric has uniform, highly resilient four-way elasticity in both warp and weft directions through scientific distribution of warp and weft stress. This effectively controls dimensional changes after washing and solves the problem of balancing elasticity and stability.

[0019] 3. A proprietary one-step dyeing process for bio-based PA510 / spandex utilizes a special acidic matte dye blending system, taking into account the differences in the chemical properties of the two fibers. This process strictly controls the liquor ratio (1:18), pH 4.5-5.5, temperature (88℃), and specific heating and holding parameters. This ensures uniform dyeing of both fibers in the same bath, high colorfastness, and protects the fabric's elasticity and texture from damage.

[0020] Beneficial effects: Compared with existing technologies, this invention demonstrates advantages in four dimensions: environmental protection, process, performance, and industrialization. It can accurately solve the pain points of existing technologies and achieve a dual breakthrough in environmental protection and high performance, as detailed below: 1. Green and Environmentally Friendly: Replacing traditional petroleum-based polyamide with bio-based PA510 reduces fossil resource consumption and carbon emissions. Its excellent biodegradability solves the problem of poor environmental performance in traditional nylon-spandex fabrics, contributing to the green transformation of the textile industry. Applying bio-based PA510 to 70D medium-fine denier high-elasticity nylon-spandex fabrics promotes the industrialization of bio-based materials, providing a new path for the green upgrading of the textile industry, and possessing economic, environmental, and promotional value.

[0021] 2. Overcoming the challenges of process adaptation: Optimizing yarn combination and ply twisting process to produce qualified 70D bio-based nylon-spandex elastic yarn; relying on the Yida 9500 rapier loom and jacquard structure optimization to solve the problems of poor fabric adaptability and performance imbalance, while taking into account both bio-based content and mechanical properties.

[0022] 3. Optimize fabric performance: By adjusting yarn count, weaving parameters, and dyeing and finishing processes, we solve problems such as poor elasticity, unstable dimensions, and uneven dyeing of conventional nylon-spandex fabrics, while taking into account hand feel, luster, and strength to meet the high-end needs of downstream industries.

[0023] 4. Enhanced industrialization feasibility: The one-step dyeing and finishing process shortens the cycle and reduces energy consumption, and the clear parameters facilitate mass production; the use of environmentally friendly dyes and auxiliaries ensures that the products meet relevant safety and industry standards, reducing the difficulty of industrialization and enhancing market competitiveness. Attached Figure Description

[0024] Figure 1 This is a schematic diagram (pattern diagram) of the fabric structure in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0026] Example 1 1. Raw material ratio Yarn selection: Yarn 1: Bio-based PA510 DTY 70D / 68F matte yarn is used as the outer fiber and spandex as the core yarn to form a covered yarn structure to meet the hand feel requirements.

[0027] Yarn 2: Four bio-based PA510 DTY 70D / 68F matte yarns are twisted together and S-twist is added, 240T / M (twist / meter), pursuing the ultimate structural stability and composite elasticity.

[0028] Spandex: Selected from Chongqing Huafeng Spandex 40D / 34F.

[0029] The warp yarn is made of bio-based PA510 DTY 70D / 68F matte yarn as the outer fiber and spandex as the core yarn, forming a covered yarn structure; weft yarn A is made of 4 bio-based PA510 DTY 70D / 68F matte yarns with S twist, 240T / M; weft yarn B is made of bio-based PA510 DTY 70D / 68F matte yarn as the outer fiber and spandex as the core yarn, forming a covered yarn structure.

[0030] 2. Weaving process The weaving process utilizes an Ida 9500 rapier loom to weave a four-way stretch fabric with a small jacquard pattern on the surface and a floating dot structure on the back. This loom features an electronic shedding mechanism, which precisely controls the warp yarns, adapting to the complex shedding requirements of the small jacquard structure. The weft insertion mechanism employs a separate reed holder, meaning the weft insertion rapier does not move with the reed holder; the reed holder remains stationary during weft insertion, effectively reducing yarn friction and preventing breakage and pilling of nylon yarns. A conjugate beat-up mechanism is used, with the reed holder actively moving forward and backward, facilitating high-speed operation of the rapier loom while ensuring even beat-up and highlighting the texture of the small jacquard fabric. Electronic take-up and electronic warp feed precisely control the warp and weft yarn tension, ensuring a flat fabric surface and avoiding defects such as weft skew and twisted edges.

[0031] The warp yarn uses bio-based PA510 DTY 70D / 68F matte yarn as the outer sheath fiber and spandex as the core yarn to form a covered yarn structure with a warp density of 160 yarns / inch. The weft yarn uses four bio-based PA510 DTY 70D / 68F matte yarns twisted together and S-twisted, with 240T / M yarn (weft A) and bio-based PA510 DTY 70D / 68F matte yarn as the outer sheath fiber and spandex as the core yarn to form a covered yarn structure (weft B). The weft yarn pattern is arranged with a weft density of 145 yarns / inch, and weft yarns A and B are arranged alternately in a 1:1 ratio. In the loom, the warp yarn float and interlacing pattern are precisely controlled by adjusting the cam curve to achieve a delicate jacquard pattern on the fabric surface and a floating dot structure on the back, taking into account both the fabric elasticity and surface texture.

[0032] The above organizational structure is as follows Figure 1 As shown, the black dots represent the floating dot structure on the fabric surface, which is evenly distributed on the fabric surface.

[0033] 3. Dyeing and finishing process research and development The core component of this fabric is PA510 yarn, whose macromolecular backbone is connected by amide bonds, and the molecular ends contain a large number of amino and carboxyl groups. The elemental composition is mainly composed of four elements: C, H, O, and N. As a typical amphoteric polyamide fiber, it has a clear "isoelectric point", which is about 5.2 to 6.8. This characteristic makes PA510 fiber suitable for dyeing with acid dyes, reactive dyes, and direct dyes.

[0034] The dyeing process for single-component PA510 fabrics is already quite mature. However, this fabric is a multi-component structure made of PA510 yarn matte loose-covered yarn (containing spandex core yarn) and four PA510 yarns twisted together. Although they are both PA510 yarns, the twist, surface condition and fiber polymerization degree of the loose-covered yarn and the twisted yarn are different, resulting in different dye adsorption rates and color uniformity. Therefore, it is necessary to select dyes specifically and optimize the dyeing process, rather than using the conventional single-component dyeing method, in order to achieve the effect of uniform dyeing of the same color in all parts of the fabric.

[0035] After multiple process trials and optimizations, a one-step dyeing and finishing route was determined, achieving uniform dyeing of the same color while protecting the elasticity of spandex and the small jacquard texture, avoiding problems such as decreased elasticity, blurred texture, and color difference. After the greige fabric is woven, it goes through flat-width cold padding, pre-setting, one-step dyeing, color fixing, drying, high-temperature setting, and inspection before leaving the vat. Each step is closely linked to ensure the quality of the finished product.

[0036] 3.1 Pretreatment of Flat-width Cold Reactor The flat-width cold padding is the core of the pretreatment process, used to remove sizing agents, oil stains, and impurities from the grey fabric and protect the spandex. At room temperature, the grey fabric is soaked in alkaline reducing agent MCL 28g / L, 32g / L ion-exchange membrane alkali, 1.2g / L oxidative desizing agent TF-127A, and 1.1g / L refining agent TF-188A. After padding, it is piled for 48 hours and then rinsed twice with warm water and once with cold water to remove chemical residues.

[0037] 3.2 Pre-order type Because the fabric contains spandex and is multi-component interwoven, it is prone to problems such as uneven tension and weft skew, requiring pre-setting treatment. The setting machine is set with a speed of 28m / min, a temperature of 122℃, and a time of 35s to control the fabric tension, maintain flatness, ensure the jacquard texture is intact, and initially stabilize the elasticity of the spandex.

[0038] 3.3 One-step staining The core step is one-step dyeing, using PA510 special acid matte dyes (Acid Matte Black A-2R 1.2%, Acid Matte Blue B-GF 0.9%, Acid Matte Gray C-2L 1.0%), with auxiliaries of ammonium sulfate 0.78g / L, glacial acetic acid 0.48g / L, and acid leveling agent AL-400 0.43g / L. Dyeing parameters: liquor ratio 1:18, pH 4.5-5.5, temperature 88℃. After the fabric is placed in the dye bath, the temperature is slowly increased (5℃ every 5 minutes), and the dyeing is maintained at this temperature for 65 minutes with continuous stirring to ensure uniform color development.

[0039] 3.4 Color Fixation Fix the color immediately after dyeing to improve color fastness. Use PA510 special acidic fixing agent, with a liquor ratio of 1:18, a temperature of 62℃, fix for 22 minutes with stirring, and then rinse twice with 40℃ warm water and once with cold water to remove residual dye and auxiliaries.

[0040] 3.5 Drying After color fixing, dry at a low temperature of 75℃ for 30 minutes, keeping the fabric surface flat and unstretched. 3.6 High temperature setting After drying, the material is set at high temperature with a speed of 22m / min, a temperature of 132℃, and a time of 45s. The tension is controlled to fix the texture and optimize the elasticity. The material is then allowed to cool naturally after setting.

[0041] Finally, the dyeing and finishing process is completed by inspecting the dyeing vat, checking the color uniformity, jacquard texture, elasticity, and fabric defects, removing defects, trimming the edges, and packaging the finished fabric after it passes inspection.

[0042] Comparative Example 1 Petroleum-based PA6 70D / 68F was used as one of the components to replace the bio-based PA510 DTY 70D / 68F, and everything else was the same as in Example 1; Comparative Example 2 Petroleum-based PA6 70D / 68F was used as one of the components to replace the bio-based PA510 DTY 70D / 68F. There was no composite tissue structure. Everything else was the same as in Example 1. Comparative Example 3 Petroleum-based PA6 70D / 68F was used as one of the components to replace the bio-based PA510 DTY 70D / 68F. A two-step staining method was used, with temperature and pH adjusted for stepwise staining. Everything else was the same as in Example 1. Test case performance testing This test example demonstrates the performance testing of the product prepared above, and the test results are shown in Table 1 below.

[0043] The moisture absorption rate was tested in accordance with GB / T 21655.1-2008 "Evaluation of the moisture absorption and quick-drying properties of textiles - Part 1: Single-item combination test method"; The elastic recovery rate was tested in accordance with GB / T 3923.1-2013 "Textiles - Tensile Properties of Fabrics - Part 1: Determination of Breaking Strength and Elongation at Break (Strip Method)"; The breaking strength was tested in accordance with GB / T 3923.1-2013 "Textiles - Tensile Properties of Fabrics - Part 1: Determination of Breaking Strength and Elongation at Break (Strip Method)"; Color fastness was tested in accordance with GB / T 3920-2008 "Textiles - Tests for color fastness - Color fastness to rubbing". Dimensional stability was tested in accordance with GB / T 8628-2001 "Determination of Dimensional Changes of Textiles After Washing and Drying".

[0044] Table 1 Performance test results of each product

[0045] As can be seen from the results in Table 1 above, Example 1 exhibits excellent elastic recovery and mechanical strength, and its color fastness reaches level 5, confirming that the fabric containing bio-based nylon 510 has good dyeing performance, color fixation and excellent toughness. At the same time, one-step dyeing helps to improve the color stability of the fabric. In contrast, the fabrics made by Comparative Examples 1, 2 and 3 using petroleum-based composites or using them alone all showed a decline in color fastness and poor color fastness. The application areas of this invention revolve around the core characteristics of the bio-based PA510 nylon-spandex fabric it produces (high bio-based content, excellent four-way elasticity, good color fastness, delicate hand feel, and dimensional stability), precisely meeting the green and low-carbon transformation needs of the textile industry and covering multiple mainstream and high-end application scenarios, as detailed below: 1. High-end apparel sector: Primarily used in casual wear, business formal wear, sportswear, outdoor clothing, and intimate apparel. This fabric combines environmental friendliness, high elasticity and resilience, and a delicate hand feel, meeting the needs for stretch and fit when wearing clothing, accommodating the range of human movement. Its matte finish and small jacquard texture enhance the high-end feel of the garments, aligning with current consumer demands for green, comfortable, and high-quality clothing.

[0046] 2. Home textiles: Suitable for sofa covers, curtains, bedding (duvet covers, pillowcases, etc.), cushions, and other home textile products. Utilizing the fabric's excellent dimensional stability, elastic recovery, and unique double-sided texture (small jacquard on the front, raised dots on the back), it ensures that home textile products are not easily deformed or damaged over long-term use and are easy to care for. Furthermore, its beautiful texture allows it to adapt to various home décor styles, balancing innovation and aesthetics.

[0047] 3. Functional textiles: Applications can be expanded to medical protective fabrics (such as elastic protective clothing and post-operative rehabilitation garments) and outdoor functional fabrics (such as lightweight outdoor jackets and sun-protective clothing). Utilizing its high bio-based environmental friendliness, stable mechanical properties, and excellent elasticity, it meets the specific requirements for environmental friendliness, breathability, elasticity, and durability in special scenarios, possessing broad expansion potential.

[0048] In addition, the jacquard texture, color and elasticity parameters of this fabric can be adjusted according to downstream demand, and it can be further extended to children's wear, workwear and other fields, helping various sub-sectors of the textile industry to achieve green upgrades, with broad application prospects.

[0049] The embodiments of the present invention have been described in detail above with reference to specific examples. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A bio-based PA510 nylon-spandex four-way stretch fabric, characterized in that, The bio-based PA510 nylon-spandex four-way stretch fabric is mainly composed of interwoven warp and weft yarns: The warp yarn is a covered yarn structure formed by using bio-based PA510 yarn as the outer fiber and spandex as the core yarn; The weft yarn includes weft yarn A and weft yarn B. Weft yarn A is a twisted yarn formed by twisting together at least two bio-based PA510 yarns. Weft yarn B is a covered yarn structure formed by using bio-based PA510 yarn as the outer fiber and spandex as the core yarn.

2. The bio-based PA510 nylon-spandex four-way stretch fabric according to claim 1, characterized in that, The fabric has a composite structure with jacquard texture on the front and dotted structure on the back.

3. The bio-based PA510 nylon-spandex four-way stretch fabric according to claim 1, characterized in that, The bio-based PA510 yarns constituting the warp, weft A, and weft B are all bio-based PA510 DTY 70D / 68F matte yarns; the spandex in the warp and weft B are all selected from spandex filament 40D / 34F.

4. The bio-based PA510 nylon-spandex four-way stretch fabric according to claim 1, characterized in that, The weft yarn A is made by plying four bio-based PA510 yarns together and adding an S-twist, with a twist of 220-260 twists / meter.

5. The bio-based PA510 nylon-spandex four-way stretch fabric according to claim 1, characterized in that, The weft yarns A and B are arranged alternately in the fabric at a ratio of 1:(0.9-1.1); the warp density of the fabric is 150-165 threads / inch, and the weft density is 140-150 threads / inch.

6. The method for preparing the bio-based PA510 nylon-spandex four-way stretch fabric according to any one of claims 1-5, characterized in that, Includes the following steps: (1) Yarn preparation: Prepare warp yarn, weft yarn A and weft yarn B; (2) Weaving: The prepared warp yarns and weft yarns A and B are woven on a loom to form a greige fabric with a jacquard texture on the surface and a dotted structure on the back. (3) Dyeing and finishing: The obtained greige fabric is subjected to flat cold piling pretreatment, pre-setting, dyeing, color fixing, drying and high temperature setting in sequence to obtain the finished fabric.

7. The preparation method according to claim 6, characterized in that, In step (2), the loom is equipped with electronic shedding, separate reed seat weft insertion, conjugate weft insertion, electronic take-up and electronic warp feeding mechanism.

8. The preparation method according to claim 6, characterized in that, In step (3), the dyeing adopts a one-step dyeing process, including: placing the pre-shaped blank in a dyeing solution containing acidic matting dye and auxiliaries, controlling the bath ratio to 1:(16-20), the pH value to 4.5-5.5, and slowly raising the temperature from room temperature to 85-90℃ at a heating rate of 3-6℃ every 5 minutes, and dyeing at this temperature for 50-70 minutes.

9. The preparation method according to claim 8, characterized in that, The acidic matting dyes include acidic matting black, acidic matting blue, and acidic matting gray; the auxiliaries include ammonium sulfate, glacial acetic acid, and acidic leveling agents.

10. The preparation method according to claim 6, characterized in that, In step (3): In the pretreatment of the flat-width cold stack, the treatment solution used includes an alkaline reducing agent, an ion-exchange membrane alkali, an oxidizing desizing agent, and a refining agent, and the stacking time is 40-50 hours; The pre-setting process parameters are: machine speed 25-30 m / min, temperature 115-126℃, time 30-40 s. The high-temperature setting process parameters are: machine speed 20-25 m / min, temperature 128-136℃, time 40-50 s.

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