Preparation method of high-breathability environment-friendly type silk-like cotton

Abstract

This invention relates to a method for preparing highly breathable and environmentally friendly imitation silk cotton. In the preparation process, soft, low-melting-point polyester fibers are used to cover the surface of the imitation silk cotton, resulting in highly breathable and environmentally friendly imitation silk cotton. The weight of the highly breathable and environmentally friendly imitation silk cotton is 200-300 g / m². 2 The oil content is 0.5~0.8wt%; the thermal resistance of the highly breathable and environmentally friendly imitation silk cotton, measured according to FZ / T 64020-2011 standard, is ≥0.310m. 2 • K / W, air permeability ≥200mm / s, loft ≥57cm 3 / g, compression elasticity ≥92%, and dimensional change rate of -3.0~1.5% after washing; the appearance defects of the high-breathability and environmentally friendly imitation silk cotton were tested according to FZ / T 64003-2011 standard, and the test results showed no surface fuzzing. This invention uses soft, low-melting-point polyester fiber to reinforce the fiber web of the imitation silk cotton, making it more environmentally friendly and effectively preventing fuzzing, while significantly improving the breathability of the imitation silk cotton.

Description

Technical Field

[0001] This invention belongs to the field of imitation silk cotton technology and relates to a method for preparing highly breathable and environmentally friendly imitation silk cotton. Background Technology

[0002] Fluff primarily refers to filling materials that utilize their own structural or morphological characteristics to support each other, or to adhere to each other through physicochemical means, ultimately forming a typical three-dimensional network pore structure. Simultaneously, it maintains a certain internal filling density to create a relatively fixed, static air network. Therefore, these products have high loft, good warmth retention and compression resilience, are lightweight, and washable, making them widely used as filling materials in various clothing, home furnishings, toys, bedding, and some industrial products. Fluff can be categorized by processing method into spray-bonded cotton, non-bonded cotton, etc.

[0003] The typical characteristic of spray-bonded cotton is that an adhesive is sprayed into the fiber web, hence the name. The fiber bonding in spray-bonded cotton is achieved by spraying the adhesive onto both sides of the fluffy fiber web. Due to the pressure applied during spraying and the vacuum suction on the other side, the adhesive can penetrate into the interior of the fiber web. After the adhesive-sprayed web is dried and cured, the junctions between the fibers bond together, giving the spray-bonded cotton a certain strength. The unbonded fibers have a high degree of freedom, resulting in a three-dimensional network structure with many pores, thus exhibiting porosity and high bulkiness. These pores also retain air, providing good warmth retention. Furthermore, the fibers used in spray-bonded cotton require moderate fineness and length, with high crimp and crimp degree, ensuring good fiber cohesion. Spray-bonded cotton products made from such fibers also have high bulkiness, compression elasticity, and elastic recovery rate. If the fibers are too fine or too long, the product will appear soft and lack firmness; while if the fibers are too short or too coarse, it will have a rough and stiff feel.

[0004] With the development and application of low-melting-point fibers, non-woven cotton has emerged in the wadding industry. Non-woven cotton is made from composite fibers mixed with low-melting-point fibers in a certain proportion, then carded into a web, heat-dried, and shaped. It has a down-like feel and warmth, earning it the reputation of "modern-day artificial feather paper." Non-woven cotton also boasts good loft, high resilience, washability, lightness, softness, and excellent warmth retention.

[0005] Based on ultrafine polyester fiber, imitation silk cotton has been developed. Imitation silk cotton typically uses ultrafine polyester fiber as its main raw material. Its typical processing characteristic is the addition of some low-melting-point heat-melting fibers as a binder and curing agent to reinforce the fiber web, resulting in a softer feel. Its texture is similar to silk quilts, and it is commonly referred to as silk floss in the market. Imitation silk cotton boasts advantages such as a delicate feel, environmental friendliness, fine texture, a silk-like surface, lightness, a silky luster, softness, a smooth surface, fluffiness, good elasticity, and excellent warmth retention. As a filling material, imitation silk cotton is mainly used in high-end winter clothing, cotton-padded garments, winter quilts, ski jackets, children's clothing, and bedding, making it an ideal alternative to down as a filling material.

[0006] Conventional imitation silk cotton, due to its low content of low-melting-point fibers and small fiber fineness, is prone to pilling or fiber slippage. It also exhibits poor water resistance, necessitating the application of adhesive to the surface to reinforce the fibers. However, this adhesive application increases the content of extractables and causes environmental pollution (Determination of extractable content in adhesives for spray-bonded cotton based on Soxhlet extraction of fiber skeleton. Test and Analysis, 2020, No. 12, 39-42). Simultaneously, the adhesive application forms a thin film with poor air permeability on the surface of the imitation silk cotton, thus affecting its air permeability (Analysis and Discussion of Spray-Bonded Cotton Process Equipment. Beijing Textile, 1993, No. 4, 12-14).

[0007] Therefore, it is necessary to study a new green and environmentally friendly preparation method for imitation silk cotton, which can solve the problem of fuzzing in imitation silk cotton without increasing its extractable content, and at the same time ensure that the breathability of imitation silk cotton is not affected. Summary of the Invention

[0008] The purpose of this invention is to solve the above-mentioned problems in the prior art and provide a method for preparing highly breathable and environmentally friendly imitation silk cotton.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A method for preparing highly breathable and environmentally friendly imitation silk cotton involves covering the surface of the imitation silk cotton with soft, low-melting-point polyester fibers during the preparation process to reinforce the fiber web, thereby obtaining highly breathable and environmentally friendly imitation silk cotton.

[0011] The single filament fineness of soft low-melting-point polyester fiber is 1.1~1.2 dtex (when the fiber fineness is 1.1~1.2 dtex, the modulus is low and the hand feel is soft).

[0012] The weight of highly breathable and environmentally friendly imitation silk cotton is 200~300g / m². 2 The thermal resistance of the highly breathable and environmentally friendly imitation silk cotton, measured according to the FZ / T 64020-2011 standard "Composite Thermal Insulation Materials - Chemical Fiber Composite Fluff," is ≥0.310m. 2• K / W, air permeability ≥200mm / s, loft ≥57cm 3 / g, compression elasticity ≥92%, water washing performance is dimensional change rate -3.0~1.5%; according to FZ / T 64003-2011 "Spray-bonded cotton wadding" standard, the appearance defects of the high-breathability environmentally friendly imitation silk cotton were tested and the test results showed that the surface was not fuzzy.

[0013] The oil content of the highly breathable and environmentally friendly imitation silk cotton is 0.5~0.8wt%, and it is tested in accordance with the GB / T 6504-2017 standard.

[0014] In existing technologies for reinforcing fibers by spraying adhesive onto the surface of imitation silk cotton, the extractable content of pure acrylic emulsion is 6.13~7.35wt%, while the extractable content of acetate acrylic emulsion and styrene acrylic emulsion adhesives is 1.73~2.89wt%. The oil content of the fibers in the spray-bonded cotton products after the spray treatment is mostly greater than 1.0wt% (national standard), ranging from 1.20~1.83wt%.

[0015] The main reason why the fiber oil content in the spray-bonded cotton products after the existing technology spray-bonding treatment is that the conversion rate of the adhesive during curing is less than 100%, between 90% and 97%. The uncured adhesive volatilizes in the processing workshop, which increases the VOC in the processing workshop; and remains in the non-woven fabric, which increases the VOC of the non-woven fabric, that is, the oil content of the fibers in the spray-bonded cotton products.

[0016] As a preferred technical solution:

[0017] The preparation method of the high-breathability and environmentally friendly imitation silk cotton described above includes the following steps: using low-melting-point polyester fiber, polyester microfiber and polyester hollow fiber with a melting point of 110℃ as inner layer raw materials, and soft low-melting-point polyester fiber and polyester microfiber as outer layer raw materials. First, the inner layer raw materials and outer layer raw materials are opened, mixed, carded and laid into a web. Then, the inner layer raw materials and outer layer raw materials after web laying are compounded, baked, surface calendered, cold-air shaped, cut and rolled to obtain high-breathability and environmentally friendly imitation silk cotton.

[0018] The low-melting-point polyester fiber has a core-sheath structure, with the sheath being a low-melting-point polyester with a melting point of 110℃ and the core being polyethylene terephthalate.

[0019] The soft, low-melting-point polyester fiber has a core-sheath structure, with the sheath layer being soft, low-melting-point polyester and the core layer being polyethylene terephthalate. The melting point of the soft, low-melting-point polyester is 130-150℃, and its glass transition temperature is 64-68℃. We aim for the inner layer of the low-melting-point polyester fiber to melt as much as possible during heat drying, which improves adhesive strength. The outer layer, however, does not require this melting; partial melting is sufficient for bonding. In this invention, the inner layer uses low-melting-point polyester fiber with a melting point of 110℃, and during heat drying, 80-100% of the sheath layer melts. The outer layer uses soft, low-melting-point polyester fiber with a melting point of 130-150℃, and during heat drying, 30-40% of the sheath layer melts. This helps reduce the overall shrinkage of the nonwoven fabric.

[0020] The above-described method for preparing highly breathable and environmentally friendly imitation silk cotton results in an outer layer with a basis weight of 9-12 g / m². 2 The content of soft low-melting-point fibers in the outer layer is above 40wt%. The content of soft low-melting-point fibers in the outer layer should not be too low. If it is below 40wt%, the reinforcement effect of the fiber web will decrease and the phenomenon of fiber shedding will occur. It is preferably 40~50wt%. This is mainly because the heat shrinkage of low-melting-point fibers is greater than that of conventional polyester. If the amount used is small, the total shrinkage of the nonwoven fabric will be small, which is beneficial to the product quality.

[0021] The above-described method for preparing a highly breathable and environmentally friendly imitation silk cotton uses soft, low-melting-point polyester fibers with a length of 90-110 mm, a breaking strength ≥3.3 cN / dtex, a breaking elongation of 40.0±5.0%, a crimp number of 8-12 / 25 mm, and a crimp degree of 12-14% (breaking strength, breaking elongation, crimp number, and crimp degree are tested according to GB / T 14464-2017 standard).

[0022] In the preparation method of the highly breathable and environmentally friendly imitation silk cotton described above, the mass ratio of the sheath to the core layer in the low-melting-point polyester fiber is 45:55~55:45.

[0023] In the above-described method for preparing a highly breathable and environmentally friendly imitation silk cotton, the mass ratio of the sheath to the core layer in the soft, low-melting-point polyester fiber is 35:65~40:60.

[0024] The spinning process parameters for soft, low-melting-point polyester fibers are as follows: sheath spinning temperature 265~275℃, core spinning temperature 283~285℃, spinning speed 900~1100m / min, ring blower temperature 20~25℃, ring blower velocity 0.5~0.8m / s, oil bath temperature 70~75℃, draw ratio 3.0~3.5 times, crimping temperature 20~25℃, crimping main pressure 0.4~0.6MPa, and crimping back pressure 0.2~0.4MPa.

[0025] The preparation method of the highly breathable and environmentally friendly imitation silk cotton described above involves the following steps for preparing soft, low-melting-point polyester: phthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, polytetrahydrofuran, and a catalyst are mixed into a slurry, and then esterified at a temperature of 240-260°C. After the esterification reaction is completed, a polycondensation reaction is carried out at a temperature of 270-275°C to obtain soft, low-melting-point polyester.

[0026] For ordinary polyesters, the molecular chain structure is a regular linear macromolecule containing benzene rings. The functional groups on the molecular chain are arranged neatly, with good regularity, poor flexibility, and high crystallinity. These characteristics hinder the reduction of the melting point, resulting in a high melting temperature. When isophthalic acid and diethylene glycol are added, the highly ordered regular structure is transformed into a disordered and chaotic structure, destroying the regularity of the molecular structure. The addition of isophthalic acid segments changes the proportion and size between different submacroscopic crystalline forms of the polyester, making polyester crystallization difficult and tending to exist in an amorphous state. The addition of diethylene glycol segments increases the flexibility of the copolyester macromolecular chain and lowers the melting point. The addition of polytetrahydrofuran, due to the large number of ether bonds and long methylene structures in polytetrahydrofuran, reduces the modulus of the copolyester and increases its flexibility.

[0027] The preparation method of the highly breathable and environmentally friendly imitation silk cotton described above uses a molar ratio of terephthalic acid, isophthalic acid, ethylene glycol and diethylene glycol of 1:0.35~0.40:1.3~1.4:0.8~1.0.

[0028] The amount of polytetrahydrofuran added is 0.04~0.06wt% of the amount of terephthalic acid added, and the number average molecular weight of polytetrahydrofuran is 2000~2500g / mol;

[0029] The amount of catalyst added is 0.03~0.04 wt% of the amount of terephthalic acid added, and the catalyst is antimony glycolate.

[0030] The preparation method of the highly breathable and environmentally friendly imitation silk cotton described above includes a baking temperature of 100~160℃, a cooling temperature of -6~2℃, and a calendering temperature of 175~195℃ for the upper roller and 195~215℃ for the lower roller.

[0031] The preparation method of the high-breathability and environmentally friendly imitation silk cotton as described above, wherein the inner layer of the high-breathability and environmentally friendly imitation silk cotton contains 15-25 wt% low-melting-point polyester fiber with a melting point of 110℃, 50-60 wt% polyester microfiber, and 15-25 wt% polyester hollow fiber; and the outer layer of the high-breathability and environmentally friendly imitation silk cotton contains 40-60 wt% soft low-melting-point polyester fiber and 40-60 wt% polyester microfiber.

[0032] The principle of this invention is as follows:

[0033] In existing technologies, adhesive spraying is commonly used to reinforce the fibers on the surface of imitation silk cotton. This adhesive spraying involves applying a chemical adhesive to the fiber web, followed by drying and curing. Currently, the adhesives used for spraying are mainly polyvinyl acetate, vinyl acetate-acrylate copolymers, and acrylic emulsions. In actual testing, it has been found that the adhesives contain a certain amount of extractables, which can increase the extractable content in the spray-bonded cotton product, i.e., increase the fiber oil content, causing the product to fail to meet the requirements of relevant standards. Simultaneously, the spray-bonded cotton processing also results in higher VOC content, impacting the environment. Furthermore, after spraying, a thin film with poor air permeability forms on the surface of the imitation silk cotton, thus affecting its breathability.

[0034] Using low-melting-point fibers to reinforce the fibers of imitation silk cotton is a future development trend. However, low-melting-point fibers typically used for bonding often have a relatively large single-filament fineness, mostly between 3 and 7 dtex. Using such low-melting-point fibers for surface reinforcement can negatively impact the feel of the imitation silk cotton. This invention creatively uses low-melting-point fibers with a single-filament fineness of 1.1 to 1.2 dtex to reinforce the fibers of imitation silk cotton, maintaining a good hand feel while reinforcing the fibers. Furthermore, using low-melting-point fibers to reinforce the fibers of imitation silk cotton also eliminates the generation of extractable substances and VOCs, making it environmentally friendly.

[0035] This invention utilizes soft, low-melting-point polyester fibers to reinforce the fibers of imitation silk cotton. Polytetrahydrofuran (PTFE) is introduced into the low-melting-point polyester. Due to the large number of ether bonds and long methylene structures in PFE, the modulus of the copolyester is reduced, increasing its softness. Simultaneously, the soft, low-melting-point polyester fiber has a relatively small single-filament fineness of 1.1~1.2 dtex, which is essentially consistent with the fine denier fibers in imitation silk cotton. The core layer has an even lower fineness, which helps to reduce the fiber modulus and make the imitation silk cotton softer. Furthermore, the basis weight of the soft, low-melting-point polyester fiber used in this invention in the outer layer structure is 9~12 g / m². 2 The outer layer contains more than 40 wt% soft low-melting-point fibers. The soft low-melting-point polyester fibers can not only bond with the inner layer structure, but also make the outer layer reach a certain density, forming a fiber web of a certain density, which meets the requirements for reinforcing fibers, and has no impact on the breathability of the imitation silk cotton. This is far better than using spray adhesive to reinforce the fiber web. Beneficial effects

[0036] This invention uses soft, low-melting-point polyester fiber to reinforce the web of imitation silk cotton, which is more environmentally friendly and effectively prevents the imitation silk cotton from pilling. This makes the air permeability of the imitation silk cotton significantly better than that of the imitation silk cotton reinforced by spraying glue, and the resulting imitation silk cotton has excellent washability. Implementation

[0037] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0038] In the embodiments of the present invention, a low-melting-point polyester with a melting point of 110°C was synthesized according to the method in the literature (Research on the Synthesis and Application of Low-Melting-Point Polyester, Petrochemical Technology and Economy, October 2011, 31-34).

[0039] The specifications of the polyester microfiber are 1.1 dtex × 51 mm. (Yangzhou Fuwei Composite Materials Co., Ltd.)

[0040] The specifications of the polyester hollow fiber are 6.6 dtex × 51 mm. Yangzhou Fuwei Composite Materials Co., Ltd. Example

[0041] A method for preparing a highly breathable and environmentally friendly imitation silk cotton, the specific steps of which are as follows:

[0042] (1) Preparation of low-melting-point polyester fibers;

[0043] Using low-melting-point polyester with a melting point of 110℃ as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled at 50:50. Low-melting-point polyester fiber with a specification of 3.3dtex×51mm is produced by the sheath-core composite spinning process.

[0044] The spinning process parameters are as follows: sheath spinning temperature 270℃, core spinning temperature 285℃, spinning speed 1030m / min, ring blower temperature 22℃, ring blower speed 0.7m / s, oil bath temperature 70℃, draw ratio 3.3 times, crimping temperature 25℃, crimping main pressure 0.4MPa, and crimping back pressure 0.3MPa.

[0045] (2) Preparation of soft, low-melting-point polyester;

[0046] Phthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, polytetrahydrofuran with a number average molecular weight of 2000 g / mol, and antimony glycol were formulated into a slurry and then subjected to an esterification reaction at a temperature of 240°C. After the esterification reaction was completed, a polycondensation reaction was carried out at a temperature of 270°C to obtain a soft low-melting-point polyester with a melting point of 150°C and a glass transition temperature of 68°C.

[0047] The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.35:1.3:0.8; the amount of polytetrahydrofuran added is 0.04 wt% of the amount of terephthalic acid added; and the amount of antimony glycol added is 0.03 wt% of the amount of terephthalic acid added.

[0048] (3) Preparation of soft, low-melting-point polyester fibers;

[0049] Using the soft low-melting-point polyester obtained in step (2) as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled to be 35:65. Soft low-melting-point polyester fiber is obtained by the sheath-core composite spinning process.

[0050] The spinning process parameters are as follows: sheath spinning temperature 265℃, core spinning temperature 283℃, spinning speed 900m / min, ring blower temperature 20℃, ring blower speed 0.5m / s, oil bath temperature 70℃, draw ratio 3.0, crimping temperature 20℃, crimping main pressure 0.4MPa, and crimping back pressure 0.2MPa.

[0051] The soft, low-melting-point polyester fiber has a length of 90 mm, a single filament fineness of 1.1 dtex, a breaking strength of 3.37 cN / dtex, a breaking elongation of 41.5%, a crimp count of 10 / 25 mm, and a crimp degree of 14%.

[0052] (4) Preparation of highly breathable and environmentally friendly imitation silk cotton;

[0053] Low-melting-point polyester fiber, polyester microfiber, and polyester hollow fiber are used as inner layer raw materials, and soft low-melting-point polyester fiber and polyester microfiber are used as outer layer raw materials. The inner and outer layer raw materials are first opened, mixed, carded, and laid into a web. Then, the inner and outer layer raw materials are compounded, baked, calendered, cold-air shaped, cut, and rolled to obtain highly breathable and environmentally friendly imitation silk cotton.

[0054] The baking temperature is 100℃; the cooling temperature is -6℃; and the heat treatment temperature is 175℃ for the upper roller and 195℃ for the lower roller.

[0055] The final product is a highly breathable and environmentally friendly imitation silk cotton, with an inner layer of imitation silk cotton covered by a soft, low-melting-point polyester fiber web; the outer layer of the highly breathable and environmentally friendly imitation silk cotton has a basis weight of 9 g / m². 2 The outer layer of the highly breathable and environmentally friendly imitation silk cotton contains 40wt% soft low-melting-point polyester fiber and 60wt% polyester microfiber; the inner layer of the highly breathable and environmentally friendly imitation silk cotton contains 15wt% low-melting-point polyester fiber, 60wt% polyester microfiber, and 25wt% polyester hollow fiber.

[0056] The weight of the highly breathable and environmentally friendly imitation silk cotton is 200g / m². 2 The oil content is 0.62 wt%; the thermal resistance of the highly breathable and environmentally friendly imitation silk cotton, measured according to the FZ / T 64020-2011 standard, is 0.346 m. 2 • K / W, breathability 221mm / s, loft 57cm 3 / g, compression elasticity rate is 93.4%, and water washing performance is dimensional change rate of -2.8%; according to FZ / T 64003-2011 standard, the appearance defects of the high-breathability environmentally friendly imitation silk cotton were tested and the test results showed that the surface was not fuzzy.

[0057] Comparative Example 1

[0058] A method for preparing imitation silk cotton involves using low-melting-point polyester fiber, polyester microfiber, and polyester hollow fiber as raw materials, and respectively performing opening, mixing, carding, web laying, glue spraying, baking, cold air setting, slitting, and rolling to obtain imitation silk cotton. The low-melting-point polyester fiber content is 15 wt%, the polyester microfiber content is 60 wt%, and the polyester hollow fiber content is 25 wt%.

[0059] The weight of the resulting imitation silk cotton is 200 g / m². 2 The oil content is 1.5 wt%; the surface of the imitation silk cotton is free of lint according to the appearance defect test; the thermal resistance of the imitation silk cotton measured according to FZ / T 64020-2011 standard is 0.250 μm. 2 • K / W; Washability: Dimensional change rate -4.3%; Air permeability (measured according to FZ / T 64003-2011 standard): 183 mm / s; Loft: 78 cm. 3 / g; compressive elasticity is 77%.

[0060] Comparing Comparative Example 1 with Example 1, it can be seen that the oil content of the imitation silk cotton in Comparative Example 1 is significantly higher than that in Example 1, and the air permeability is significantly lower than that in Example 1. This is because the conversion rate of the adhesive during curing is less than 100%, between 90% and 97%. Uncured adhesive remains in the nonwoven fabric, increasing the VOC of the nonwoven fabric, i.e., the oil content of the fibers in the spray-bonded cotton product. After spraying, the cured adhesive forms a thin film with poor air permeability on the surface of the imitation silk cotton, thus affecting the air permeability of the imitation silk cotton. Example

[0061] A method for preparing a highly breathable and environmentally friendly imitation silk cotton, the specific steps of which are as follows:

[0062] (1) Preparation of low-melting-point polyester fibers;

[0063] Using low-melting-point polyester with a melting point of 110℃ as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled at 50:50. Low-melting-point polyester fiber with a specification of 3.3dtex×51mm is produced by the sheath-core composite spinning process.

[0064] The spinning process parameters are as follows: sheath spinning temperature 270℃, core spinning temperature 285℃, spinning speed 1030m / min, ring blower temperature 22℃, ring blower speed 0.7m / s, oil bath temperature 70℃, draw ratio 3.3 times, crimping temperature 25℃, crimping main pressure 0.4MPa, and crimping back pressure 0.3MPa.

[0065] (2) Preparation of soft, low-melting-point polyester;

[0066] Phthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, polytetrahydrofuran with a number average molecular weight of 2000 g / mol, and antimony glycol were mixed to form a slurry, which was then subjected to an esterification reaction at a temperature of 240°C. After the esterification reaction was completed, a polycondensation reaction was carried out at a temperature of 270°C to obtain a soft low-melting-point polyester with a melting point of 145°C and a glass transition temperature of 66°C.

[0067] The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.35:1.35:0.9; the amount of polytetrahydrofuran added is 0.06 wt% of the amount of terephthalic acid added; and the amount of antimony glycol added is 0.03 wt% of the amount of terephthalic acid added.

[0068] (3) Preparation of soft, low-melting-point polyester fibers;

[0069] Using the soft low-melting-point polyester obtained in step (2) as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled to be 35:65. Soft low-melting-point polyester fiber is obtained by the sheath-core composite spinning process.

[0070] The spinning process parameters are as follows: sheath spinning temperature 265℃, core spinning temperature 283℃, spinning speed 900m / min, ring blower temperature 22℃, ring blower speed 0.5m / s, oil bath temperature 70℃, draw ratio 3.2 times, crimping temperature 22℃, crimping main pressure 0.6MPa, and crimping back pressure 0.4MPa.

[0071] The soft, low-melting-point polyester fiber has a length of 90 mm, a single filament fineness of 1.2 dtex, a breaking strength of 3.42 cN / dtex, a breaking elongation of 35.0%, a crimp count of 8 / 25 mm, and a crimp degree of 13%.

[0072] (4) Preparation of highly breathable and environmentally friendly imitation silk cotton;

[0073] Low-melting-point polyester fiber, polyester microfiber, and polyester hollow fiber are used as inner layer raw materials, and soft low-melting-point polyester fiber and polyester microfiber are used as outer layer raw materials. The inner and outer layer raw materials are first opened, mixed, carded, and laid into a web. Then, the inner and outer layer raw materials are compounded, baked, calendered, cold-air shaped, cut, and rolled to obtain highly breathable and environmentally friendly imitation silk cotton.

[0074] The baking temperature is 100℃; the cooling temperature is -2℃; and the heat treatment temperature is 178℃ for the upper roller and 198℃ for the lower roller.

[0075] The final product is a highly breathable and environmentally friendly imitation silk cotton, with an inner layer of imitation silk cotton covered by a soft, low-melting-point polyester fiber web; the outer layer of the highly breathable and environmentally friendly imitation silk cotton has a basis weight of 9 g / m². 2 The outer layer of the highly breathable and environmentally friendly imitation silk cotton contains 40wt% soft low-melting-point polyester fiber and 60wt% polyester microfiber; the inner layer of the highly breathable and environmentally friendly imitation silk cotton contains 20wt% low-melting-point polyester fiber, 60wt% polyester microfiber, and 20wt% polyester hollow fiber.

[0076] The weight of the highly breathable and environmentally friendly imitation silk cotton is 200g / m². 2 The oil content is 0.50 wt%; the thermal resistance of the highly breathable and environmentally friendly imitation silk cotton, measured according to the FZ / T 64020-2011 standard, is 0.322 m. 2 • K / W, breathability 217mm / s, loft 61cm 3 / g, compression elasticity rate is 94.7%, and water washing performance is dimensional change rate of -3.0%; according to FZ / T 64003-2011 standard, the appearance defects of the high-breathability environmentally friendly imitation silk cotton were tested and the test results showed that the surface was not fuzzy. Example

[0077] A method for preparing a highly breathable and environmentally friendly imitation silk cotton, the specific steps of which are as follows:

[0078] (1) Preparation of low-melting-point polyester fibers;

[0079] Using low-melting-point polyester with a melting point of 110℃ as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled at 50:50. Low-melting-point polyester fiber with a specification of 3.3dtex×51mm is produced by the sheath-core composite spinning process.

[0080] The spinning process parameters are as follows: sheath spinning temperature 270℃, core spinning temperature 285℃, spinning speed 1030m / min, ring blower temperature 22℃, ring blower speed 0.7m / s, oil bath temperature 70℃, draw ratio 3.3 times, crimping temperature 25℃, crimping main pressure 0.4MPa, and crimping back pressure 0.3MPa.

[0081] (2) Preparation of soft, low-melting-point polyester;

[0082] Phthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, polytetrahydrofuran with a number average molecular weight of 2200 g / mol, and antimony glycol were formulated into a slurry and then subjected to an esterification reaction at a temperature of 245°C. After the esterification reaction was completed, a polycondensation reaction was carried out at a temperature of 272°C to obtain a soft low-melting-point polyester with a melting point of 138°C and a glass transition temperature of 65°C.

[0083] The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.38:1.3:1; the amount of polytetrahydrofuran added is 0.04 wt% of the amount of terephthalic acid added; and the amount of antimony glycol added is 0.03 wt% of the amount of terephthalic acid added.

[0084] (3) Preparation of soft, low-melting-point polyester fibers;

[0085] Using the soft low-melting-point polyester obtained in step (2) as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled to be 35:65. Soft low-melting-point polyester fiber is obtained by the sheath-core composite spinning process.

[0086] The spinning process parameters are as follows: sheath spinning temperature 268℃, core spinning temperature 284℃, spinning speed 1000m / min, ring blower temperature 25℃, ring blower speed 0.6m / s, oil bath temperature 72℃, draw ratio 3.2 times, crimping temperature 25℃, crimping main pressure 0.5MPa, and crimping back pressure 0.3MPa.

[0087] The soft, low-melting-point polyester fiber has a length of 100 mm, a single filament fineness of 1.1 dtex, a breaking strength of 3.51 cN / dtex, a breaking elongation of 43.7%, a crimp count of 12 / 25 mm, and a crimp degree of 12%.

[0088] (4) Preparation of highly breathable and environmentally friendly imitation silk cotton;

[0089] Low-melting-point polyester fiber, polyester microfiber, and polyester hollow fiber are used as inner layer raw materials, and soft low-melting-point polyester fiber and polyester microfiber are used as outer layer raw materials. The inner and outer layer raw materials are first opened, mixed, carded, and laid into a web. Then, the inner and outer layer raw materials are compounded, baked, calendered, cold-air shaped, cut, and rolled to obtain highly breathable and environmentally friendly imitation silk cotton.

[0090] The baking temperature is 120℃; the cooling temperature is 0℃; and the heat treatment temperature is 180℃ for the upper roller and 200℃ for the lower roller.

[0091] The final product is a highly breathable and environmentally friendly imitation silk cotton, with an inner layer of imitation silk cotton covered by a soft, low-melting-point polyester fiber web; the outer layer of the highly breathable and environmentally friendly imitation silk cotton has a weight of 10 g / m². 2 The outer layer of the highly breathable and environmentally friendly imitation silk cotton contains 40wt% soft low-melting-point polyester fiber and 60wt% polyester microfiber; the inner layer of the highly breathable and environmentally friendly imitation silk cotton contains 25wt% low-melting-point polyester fiber, 50wt% polyester microfiber, and 25wt% polyester hollow fiber.

[0092] The weight of the highly breathable and environmentally friendly imitation silk cotton is 220g / m². 2 The oil content is 0.80 wt%; the thermal resistance of the highly breathable and environmentally friendly imitation silk cotton, measured according to the FZ / T 64020-2011 standard, is 0.337 m. 2 • K / W, breathability 225mm / s, loft 59cm 3 / g, compression elasticity rate is 92.2%, and water washing performance is 0% dimensional change rate; according to FZ / T 64003-2011 standard, the appearance defects of the high-breathability environmentally friendly imitation silk cotton were tested and the test results showed that the surface was not fuzzy. Example

[0093] A method for preparing a highly breathable and environmentally friendly imitation silk cotton, the specific steps of which are as follows:

[0094] (1) Preparation of low-melting-point polyester fibers;

[0095] Using low-melting-point polyester with a melting point of 110℃ as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled at 50:50. Low-melting-point polyester fiber with a specification of 3.3dtex×51mm is produced by the sheath-core composite spinning process.

[0096] The spinning process parameters are as follows: sheath spinning temperature 270℃, core spinning temperature 285℃, spinning speed 1030m / min, ring blower temperature 22℃, ring blower speed 0.7m / s, oil bath temperature 70℃, draw ratio 3.3 times, crimping temperature 25℃, crimping main pressure 0.4MPa, and crimping back pressure 0.3MPa.

[0097] (2) Preparation of soft, low-melting-point polyester;

[0098] Phthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, polytetrahydrofuran with a number average molecular weight of 2200 g / mol, and antimony glycol were formulated into a slurry and then subjected to an esterification reaction at a temperature of 248°C. After the esterification reaction was completed, a polycondensation reaction was carried out at a temperature of 272°C to obtain a soft low-melting-point polyester with a melting point of 130°C and a glass transition temperature of 64°C.

[0099] The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.4:1.3:1; the amount of polytetrahydrofuran added is 0.05 wt% of the amount of terephthalic acid added; and the amount of antimony glycolate added is 0.04 wt% of the amount of terephthalic acid added.

[0100] (3) Preparation of soft, low-melting-point polyester fibers;

[0101] Using the soft low-melting-point polyester obtained in step (2) as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled to be 40:60. Soft low-melting-point polyester fiber is obtained by the sheath-core composite spinning process.

[0102] The spinning process parameters are as follows: sheath spinning temperature 270℃, core spinning temperature 285℃, spinning speed 1100m / min, ring blower temperature 25℃, ring blower speed 0.8m / s, oil bath temperature 75℃, draw ratio 3.2 times, crimping temperature 25℃, crimping main pressure 0.5MPa, and crimping back pressure 0.3MPa.

[0103] The soft, low-melting-point polyester fiber has a length of 100 mm, a single filament fineness of 1.2 dtex, a breaking strength of 3.47 cN / dtex, a breaking elongation of 45.0%, a crimp count of 12 / 25 mm, and a crimp degree of 14%.

[0104] (4) Preparation of highly breathable and environmentally friendly imitation silk cotton;

[0105] Low-melting-point polyester fiber, polyester microfiber, and polyester hollow fiber are used as inner layer raw materials, and soft low-melting-point polyester fiber and polyester microfiber are used as outer layer raw materials. The inner and outer layer raw materials are first opened, mixed, carded, and laid into a web. Then, the inner and outer layer raw materials are compounded, baked, calendered, cold-air shaped, cut, and rolled to obtain highly breathable and environmentally friendly imitation silk cotton.

[0106] The baking temperature is 125℃; the cooling temperature is 0℃; and the heat treatment temperature is 190℃ for the upper roller and 205℃ for the lower roller.

[0107] The final product is a highly breathable and environmentally friendly imitation silk cotton, with an inner layer of imitation silk cotton covered by a soft, low-melting-point polyester fiber web; the outer layer of the highly breathable and environmentally friendly imitation silk cotton has a basis weight of 12 g / m². 2 The outer layer of the highly breathable and environmentally friendly imitation silk cotton contains 50wt% soft low-melting-point polyester fiber and 50wt% polyester microfiber; the inner layer of the highly breathable and environmentally friendly imitation silk cotton contains 15wt% low-melting-point polyester fiber, 60wt% polyester microfiber, and 25wt% polyester hollow fiber.

[0108] The weight of the highly breathable and environmentally friendly imitation silk cotton is 250g / m². 2 The oil content is 0.72 wt%; the thermal resistance of the highly breathable and environmentally friendly imitation silk cotton, measured according to the FZ / T 64020-2011 standard, is 0.329 m. 2 • K / W, breathability 219mm / s, loft 58cm 3 / g, compression elasticity rate is 92.6%, and water washing performance is dimensional change rate of -1.7%; according to FZ / T 64003-2011 standard, the appearance defects of the high-breathability environmentally friendly imitation silk cotton were tested and the test results showed that the surface was not fuzzy. Example

[0109] A method for preparing a highly breathable and environmentally friendly imitation silk cotton, the specific steps of which are as follows:

[0110] (1) Preparation of low-melting-point polyester fibers;

[0111] Using low-melting-point polyester with a melting point of 110℃ as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled at 50:50. Low-melting-point polyester fiber with a specification of 3.3dtex×51mm is produced by the sheath-core composite spinning process.

[0112] The spinning process parameters are as follows: sheath spinning temperature 270℃, core spinning temperature 285℃, spinning speed 1030m / min, ring blower temperature 22℃, ring blower speed 0.7m / s, oil bath temperature 70℃, draw ratio 3.3 times, crimping temperature 25℃, crimping main pressure 0.4MPa, and crimping back pressure 0.3MPa.

[0113] (2) Preparation of soft, low-melting-point polyester;

[0114] Phthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, polytetrahydrofuran with a number average molecular weight of 2500 g / mol, and antimony glycol were formulated into a slurry and then subjected to an esterification reaction at 250°C. After the esterification reaction was completed, a polycondensation reaction was carried out at 275°C to obtain a soft, low-melting-point polyester with a melting point of 143°C and a glass transition temperature of 66°C.

[0115] The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.36:1.36:0.9; the amount of polytetrahydrofuran added is 0.05 wt% of the amount of terephthalic acid added; and the amount of antimony glycol added is 0.04 wt% of the amount of terephthalic acid added.

[0116] (3) Preparation of soft, low-melting-point polyester fibers;

[0117] Using the soft low-melting-point polyester obtained in step (2) as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled to be 40:60. Soft low-melting-point polyester fiber is obtained by the sheath-core composite spinning process.

[0118] The spinning process parameters are as follows: sheath spinning temperature 272℃, core spinning temperature 285℃, spinning speed 1100m / min, ring blower temperature 25℃, ring blower speed 0.8m / s, oil bath temperature 75℃, draw ratio 3.5 times, crimping temperature 24℃, crimping main pressure 0.5MPa, crimping back pressure 0.3MPa;

[0119] The soft, low-melting-point polyester fiber has a length of 110 mm, a single filament fineness of 1.1 dtex, a breaking strength of 3.44 cN / dtex, a breaking elongation of 39.6%, a crimp count of 9 / 25 mm, and a crimp degree of 12%.

[0120] (4) Preparation of highly breathable and environmentally friendly imitation silk cotton;

[0121] Low-melting-point polyester fiber, polyester microfiber, and polyester hollow fiber are used as inner layer raw materials, and soft low-melting-point polyester fiber and polyester microfiber are used as outer layer raw materials. The inner and outer layer raw materials are first opened, mixed, carded, and laid into a web. Then, the inner and outer layer raw materials are compounded, baked, calendered, cold-air shaped, cut, and rolled to obtain highly breathable and environmentally friendly imitation silk cotton.

[0122] The baking temperature is 140℃; the cooling temperature is 2℃; and the heat treatment temperature is 195℃ for the upper roller and 210℃ for the lower roller.

[0123] The final product is a highly breathable and environmentally friendly imitation silk cotton, with an inner layer of imitation silk cotton covered by a soft, low-melting-point polyester fiber web; the outer layer of the highly breathable and environmentally friendly imitation silk cotton has a basis weight of 12 g / m². 2 The outer layer of the highly breathable and environmentally friendly imitation silk cotton contains 50 wt% soft low-melting-point polyester fiber and 50 wt% polyester microfiber; the inner layer of the highly breathable and environmentally friendly imitation silk cotton contains 20 wt% low-melting-point polyester fiber, 60 wt% polyester microfiber, and 20 wt% polyester hollow fiber.

[0124] The weight of the highly breathable and environmentally friendly imitation silk cotton is 300g / m². 2 The oil content is 0.67 wt%; the thermal resistance of the highly breathable and environmentally friendly imitation silk cotton, measured according to the FZ / T 64020-2011 standard, is 0.332 m. 2 • K / W, air permeability 206mm / s, loft 64cm 3 / g, compression elasticity rate is 93.3%, and water washing performance is dimensional change rate of 0.9%; according to FZ / T 64003-2011 standard, the appearance defects of the high-breathability environmentally friendly imitation silk cotton were tested and the test results showed that the surface was not fuzzy. Example

[0125] A method for preparing a highly breathable and environmentally friendly imitation silk cotton, the specific steps of which are as follows:

[0126] (1) Preparation of low-melting-point polyester fibers;

[0127] Using low-melting-point polyester with a melting point of 110℃ as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled at 50:50. Low-melting-point polyester fiber with a specification of 3.3dtex×51mm is produced by the sheath-core composite spinning process.

[0128] The spinning process parameters are as follows: sheath spinning temperature 270℃, core spinning temperature 285℃, spinning speed 1030m / min, ring blower temperature 22℃, ring blower speed 0.7m / s, oil bath temperature 70℃, draw ratio 3.3 times, crimping temperature 25℃, crimping main pressure 0.4MPa, and crimping back pressure 0.3MPa.

[0129] (2) Preparation of soft, low-melting-point polyester;

[0130] Phthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, polytetrahydrofuran with a number average molecular weight of 2500 g / mol, and antimony glycol were formulated into a slurry and then subjected to an esterification reaction at a temperature of 250°C. After the esterification reaction was completed, a polycondensation reaction was carried out at a temperature of 275°C to obtain a soft low-melting-point polyester with a melting point of 133°C and a glass transition temperature of 64°C.

[0131] The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.4:1.35:1; the amount of polytetrahydrofuran added is 0.04 wt% of the amount of terephthalic acid added; and the amount of antimony glycol added is 0.04 wt% of the amount of terephthalic acid added.

[0132] (3) Preparation of soft, low-melting-point polyester fibers;

[0133] Using the soft low-melting-point polyester obtained in step (2) as the sheath material and polyethylene terephthalate as the core material, the mass ratio of the sheath and the core is controlled to be 40:60. Soft low-melting-point polyester fiber is obtained by the sheath-core composite spinning process.

[0134] The spinning process parameters are as follows: sheath spinning temperature 275℃, core spinning temperature 285℃, spinning speed 1100m / min, ring blower temperature 25℃, ring blower speed 0.8m / s, oil bath temperature 75℃, draw ratio 3.5 times, crimping temperature 24℃, crimping main pressure 0.5MPa, crimping back pressure 0.3MPa;

[0135] The soft, low-melting-point polyester fiber has a length of 110 mm, a single filament fineness of 1.1 dtex, a breaking strength of 3.53 cN / dtex, a breaking elongation of 41.8%, a crimp count of 10 / 25 mm, and a crimp degree of 12%.

[0136] (4) Preparation of highly breathable and environmentally friendly imitation silk cotton;

[0137] Low-melting-point polyester fiber, polyester microfiber, and polyester hollow fiber are used as inner layer raw materials, and soft low-melting-point polyester fiber and polyester microfiber are used as outer layer raw materials. The inner and outer layer raw materials are first opened, mixed, carded, and laid into a web. Then, the inner and outer layer raw materials are compounded, baked, calendered, cold-air shaped, cut, and rolled to obtain highly breathable and environmentally friendly imitation silk cotton.

[0138] The baking temperature is 160℃; the cooling temperature is 2℃; and the heat treatment temperature is 195℃ for the upper roller and 215℃ for the lower roller.

[0139] The final product is a highly breathable and environmentally friendly imitation silk cotton, with an inner layer of imitation silk cotton covered by a soft, low-melting-point polyester fiber web; the outer layer of the highly breathable and environmentally friendly imitation silk cotton has a basis weight of 12 g / m². 2 The outer layer of the highly breathable and environmentally friendly imitation silk cotton contains 60wt% soft low-melting-point polyester fiber and 40wt% polyester microfiber; the inner layer of the highly breathable and environmentally friendly imitation silk cotton contains 20wt% low-melting-point polyester fiber, 60wt% polyester microfiber, and 20wt% polyester hollow fiber.

[0140] The weight of the highly breathable and environmentally friendly imitation silk cotton is 300g / m². 2 The oil content is 0.73 wt%; the thermal resistance of the highly breathable and environmentally friendly imitation silk cotton, measured according to the FZ / T 64020-2011 standard, is 0.319 m. 2 • K / W, air permeability 211mm / s, loft 60cm 3 / g, compression elasticity rate is 93.7%, and water washing performance is dimensional change rate of 1.5%; according to FZ / T 64003-2011 standard, the appearance defects of the high-breathability environmentally friendly imitation silk cotton were tested and the test results showed that the surface was not fuzzy.

Claims

1. A method for preparing a highly breathable and environmentally friendly imitation silk cotton, characterized in that: In the process of preparing imitation silk cotton, soft, low-melting-point polyester fibers are used to cover the surface of the imitation silk cotton to obtain highly breathable and environmentally friendly imitation silk cotton. The single filament fineness of soft, low-melting-point polyester fiber is 1.1~1.2 dtex; The weight of highly breathable and environmentally friendly imitation silk cotton is 200~300g / m². 2 The thermal resistance of the highly breathable and environmentally friendly imitation silk cotton, measured according to the FZ / T 64020-2011 standard, is ≥0.310m. 2 • K / W, air permeability ≥200mm / s, loft ≥57cm 3 / g, compression elasticity ≥92%, water washing performance is dimensional change rate -3.0~1.5%; according to FZ / T 64003-2011 standard, the appearance defects of the high-breathable and environmentally friendly imitation silk cotton are tested and the test results show that the surface does not fuzz. The oil content of highly breathable and environmentally friendly imitation silk cotton is 0.5~0.8wt%; Low-melting-point polyester fiber, polyester microfiber, and polyester hollow fiber are used as inner layer raw materials, and soft low-melting-point polyester fiber and polyester microfiber are used as outer layer raw materials. The inner and outer layer raw materials are first opened, mixed, carded, and laid into a web. Then, the inner and outer layer raw materials are compounded, baked, calendered, cold-air shaped, cut, and rolled to obtain highly breathable and environmentally friendly imitation silk cotton. The low-melting-point polyester fiber has a core-sheath structure, with the sheath being a low-melting-point polyester with a melting point of 110℃ and the core being polyethylene terephthalate. The soft, low-melting-point polyester fiber has a core-sheath structure, with the sheath being soft, low-melting-point polyester and the core being polyethylene terephthalate; the melting point of the soft, low-melting-point polyester is 130~150℃, and the glass transition temperature is 64~68℃. In low-melting-point polyester fibers, the mass ratio of the sheath to the core is 45:55 to 55:

45. In soft, low-melting-point polyester fibers, the mass ratio of the sheath to the core layer is 35:65 to 40:

60. The spinning process parameters for soft, low-melting-point polyester fibers are as follows: sheath spinning temperature 265~275℃, core spinning temperature 283~285℃, spinning speed 900~1100m / min, ring blower temperature 20~25℃, ring blower velocity 0.5~0.8m / s, oil bath temperature 70~75℃, draw ratio 3.0~3.5 times, crimping temperature 20~25℃, crimping main pressure 0.4~0.6MPa, crimping back pressure 0.2~0.4MPa; The preparation process of soft low-melting-point polyester is as follows: terephthalic acid, isophthalic acid, ethylene glycol, diethylene glycol, polytetrahydrofuran and catalyst are mixed into a slurry and then subjected to esterification reaction at a temperature of 240~260℃; after the esterification reaction is completed, polycondensation reaction is carried out at a temperature of 270~275℃ to obtain soft low-melting-point polyester. The molar ratio of terephthalic acid, isophthalic acid, ethylene glycol, and diethylene glycol is 1:0.35~0.40:1.3~1.4:0.8~1.0; The amount of polytetrahydrofuran added is 0.04~0.06wt% of the amount of terephthalic acid added, and the number average molecular weight of polytetrahydrofuran is 2000~2500g / mol; The amount of catalyst added is 0.03~0.04 wt% of the amount of terephthalic acid added, and the catalyst is antimony glycolate.

2. The method for preparing a highly breathable and environmentally friendly imitation silk cotton according to claim 1, characterized in that, The outer layer of the highly breathable and environmentally friendly imitation silk cotton has a weight of 9~12g / m². 2 The outer layer contains more than 40 wt% soft, low-melting-point polyester fiber.

3. The method for preparing a highly breathable and environmentally friendly imitation silk cotton according to claim 2, characterized in that, The length of the soft low-melting-point polyester fiber is 90~110mm, the breaking strength is ≥3.3cN / dtex, the breaking elongation is 40.0±5.0%, the number of crimps is 8~12 / 25mm, and the crimp degree is 12~14%.

4. The method for preparing a highly breathable and environmentally friendly imitation silk cotton according to claim 1, characterized in that, Baking temperature is 100~160℃; cooling temperature is -6~2℃; heat setting temperature is: upper roller 175~195℃, lower roller 195~215℃.

5. The method for preparing a highly breathable and environmentally friendly imitation silk cotton according to claim 1, characterized in that, The inner layer of the highly breathable and environmentally friendly imitation silk cotton contains 15-25 wt% low-melting-point polyester fiber, 50-60 wt% polyester microfiber, and 15-25 wt% polyester hollow fiber; the outer layer of the highly breathable and environmentally friendly imitation silk cotton contains 40-60 wt% soft low-melting-point polyester fiber and 40-60 wt% polyester microfiber.