Cotton-feeling composite polyester yarn and preparation method of cotton-feeling polyester fabric

Abstract

The invention discloses a cotton-feeling composite polyester yarn and a preparation method of a cotton-feeling polyester fabric. The preparation method of the cotton-feeling composite polyester yarn comprises the following steps: preparing a first polyethylene glycol terephthalate fiber with a special-shaped cross section and a moisture regain of 1.5-3%; preparing a second polybutylene terephthalate fiber with thermal shrinkage; the first fiber and the second fiber are mixed and then spun. The preparation method of the cotton-feeling polyester fabric comprises the following steps: weaving the cotton-feeling composite polyester yarn prepared by the method as a raw material to obtain gray fabric; and dyeing and finishing the gray fabric, which comprises at least one heat treatment step, so that the second fibers in the cotton-feeling composite polyester yarns are shrunk. Through combination of specific fibers and key heat treatment, the obtained yarn and fabric have excellent wearing comfort and anti-pilling performance.

Description

Technical Field

[0001] The invention relates to the technical field of fabrics, and in particular to a cotton-feel composite polyester yarn, a cotton-feel polyester fabric and corresponding preparation methods. Background Art

[0002] Traditional polyester staple fiber fabrics, due to their molecular structure, typically exhibit excellent strength and shape retention, making them widely used in various clothing and home textile products. However, precisely because of their inherent low moisture absorption and fiber surface properties, these traditional cotton-like polyester fabrics often lack skin-friendly comfort and lack the thermal and moisture regulation capabilities comparable to cotton fabrics. Furthermore, their yarns and fabric surfaces are prone to hairiness during processing and use, resulting in poor finish and subsequent pilling. These defects seriously affect the wearing quality and long-lasting appearance of clothing.

[0003] To address the above-mentioned issues, various improvements have been attempted in the prior art. For example, fiber modification, such as the use of fibers with special cross-sections, aims to improve the fiber's moisture-conducting properties, thereby reducing the feeling of stuffiness when worn. However, while such modifications can improve moisture-conducting properties to a certain extent, their effectiveness in comprehensively enhancing the soft, cotton-like feel and fundamentally resolving the pilling problem is limited. Another common improvement method is post-finishing technology, such as the use of anti-pilling additives during the fabric finishing stage. However, this type of chemical finishing method suffers from insufficient durability, with the effect fading after repeated washings, and some additives affecting the feel of the fabric, while failing to effectively enhance wearing comfort.

[0004] Therefore, current polyester fiber yarns or fabrics still cannot achieve a good balance between wearing comfort and anti-pilling performance. Summary of the Invention

[0005] The purpose of the present invention is to overcome the above-mentioned defects or problems existing in the background technology and provide a method for preparing a cotton-feel composite polyester yarn and a cotton-feel polyester fabric. The yarn and the fabric prepared using the yarn achieve a good balance in wearing comfort and anti-pilling performance.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] Technical solution 1: A method for preparing a cotton-feel composite polyester yarn, which includes the following steps: preparing a first fiber: blending a polyethylene terephthalate raw material with a hygroscopic modifier, and forming a first spun fiber with a special cross-section by melt spinning; the first spun fiber is stretched, heat-set and cut to obtain the first fiber; the moisture regain of the first fiber is between 1.5% and 3%; preparing a second fiber: forming a second spun fiber from a polybutylene terephthalate raw material by melt spinning; the second spun fiber is stretched, heat-set and cut to obtain the second fiber with heat shrinkage; the first fiber and the second fiber are mixed and spun to obtain the cotton-feel composite polyester yarn.

[0008] Technical Solution 2 based on Technical Solution 1: in the step of preparing the first fiber, the polyethylene terephthalate raw material is spinning-grade polyethylene terephthalate chips, and the hygroscopic modifier is a hygroscopic polyester functional masterbatch; and in the step of preparing the second fiber, the polybutylene terephthalate raw material is spinning-grade polybutylene terephthalate chips.

[0009] Technical Solution 3 based on Technical Solution 1: The melt spinning in the step of preparing the first fiber includes: melt extrusion at a temperature of 240°C to 290°C, and spinning through a spinneret with special-shaped holes at a spinning temperature of 240°C to 290°C and a spinning speed of 1200m / min to 1500m / min; and the stretching includes: in a stretching water tank at 60°C to 85°C, with a pre-stretching ratio of 1.05 to 1.10 and a main stretching ratio of 1.5 to 3.5.

[0010] Technical Solution 4 based on Technical Solution 1: The melt spinning in the step of preparing the second fiber includes: melt extrusion at a temperature of 240°C to 280°C, and spinning through a porous spinneret at a spinning temperature of 230°C to 270°C and a spinning speed of 1200m / min to 1500m / min; and the stretching includes: in a stretching water tank at 60°C to 85°C, with a pre-stretching ratio of 1.05 to 1.10 and a main stretching ratio of 1.5 to 3.5.

[0011] Technical solution 5 based on technical solution 1: the special-shaped cross-section of the first fiber is selected from a cross shape, a Y shape, or a four-leaf clover shape; and the moisture regain of the first fiber is in the range of 1.5% to 2.5%.

[0012] Technical solution six based on technical solution one: the fineness of the first fiber is 0.5D to 1.5D, and its length is 38mm to 76mm; and the fineness of the second fiber is 0.5D to 1.5D, and its length is 38mm to 76mm.

[0013] Technical Solution 7 based on Technical Solution 1: In the step of spinning the first fiber and the second fiber after mixing, the proportion of the first fiber is 65% to 75% by weight, and the proportion of the second fiber is 25% to 35% by weight.

[0014] Technical solution eight based on technical solution one: the spinning step adopts a siro compact spinning process.

[0015] Technical solution nine based on technical solution one: the imperial count of the cotton-feel composite polyester yarn is 50S to 60S.

[0016] In addition, the present invention also provides technical solution ten: a method for preparing a cotton-feel polyester fabric, which comprises the following steps: using the cotton-feel composite polyester yarn prepared by the preparation method of the cotton-feel composite polyester yarn described in any one of technical solutions one to nine as a raw material for weaving to obtain a grey cloth; performing dyeing and finishing treatment on the grey cloth, the dyeing and finishing treatment comprising at least one heat treatment step, and the process parameters of the heat treatment step are sufficient to cause the second fiber in the cotton-feel composite polyester yarn to shrink.

[0017] Technical Solution 11 based on Technical Solution 10: The weaving is knitting, and the formed grey fabric structure is a polyester-covered polyester-spandex plain weave structure, wherein the face yarn is made of the cotton-feel composite polyester yarn, and the base yarn is made of polybutylene terephthalate filament.

[0018] Technical Solution 12 based on Technical Solution 10: The dyeing and finishing treatment includes degreasing and shrinking, grey cloth setting, dyeing, reduction cleaning, finished product setting and drying processes in sequence; the degreasing and shrinking process is carried out at a temperature of 95°C to 105°C; the grey cloth setting process is carried out at a temperature of 180°C to 195°C; the finished product setting process is carried out at a temperature of 145°C to 155°C.

[0019] From the above description of the present invention, it can be seen that compared with the prior art, the present invention has the following beneficial effects:

[0020] Technical Solution 1 defines a method for producing a cotton-feel composite polyester yarn. Its core involves separately preparing two polyester fibers with distinct properties designed to complement each other, then blending and spinning them into yarn. This method aims to address the common challenge of balancing comfort and pilling resistance in existing cotton-feel polyester fabrics. This effect stems not simply from the individual properties of the two fibers, but rather from their integration and interaction within the yarn structure.

[0021] First, the method produces a first fiber. This step specifies the need to blend polyethylene terephthalate (PET) with a hygroscopic modifier and melt-spin to form a spun fiber with a profiled cross-section. The final fiber is then stretched, heat-set, and cut. Crucially, the claim directly stipulates that this first fiber must possess two core characteristics: a profiled cross-section and a moisture regain within a specified range of 1.5% to 3%. The profiled cross-section, by altering the fiber's physical morphology, naturally enhances the capillary effect of the fiber assembly, facilitating the rapid conduction and diffusion of sweat, thereby improving breathability and a sense of dryness. A moisture regain of 1.5% to 3% is significantly higher than that of standard PET fibers, meaning the fiber can absorb more water and possesses physical properties closer to those of natural fibers. This significantly improves the dryness and airtightness often associated with traditional polyester fibers, imparting a soft, skin-friendly feel. Therefore, the first fiber produced in this step, with its specific cross-sectional shape and defined high moisture regain range, lays the foundation for the superior wearing comfort of the final composite yarn.

[0022] Secondly, the method prepares a second fiber. This step specifies the use of polybutylene terephthalate as a raw material, and after melt spinning, stretching, heat setting, and cutting, the final second fiber is obtained. It also directly defines the key characteristic of this second fiber as "heat shrinkage." PBT material itself has thermophysical properties that are different from PET. Through specific processing techniques, it can retain the ability to shrink under subsequent heating conditions. This step stipulates that PBT fiber with this "heat shrinkage" must be prepared, creating the necessary conditions for the subsequent use of this property to solve the pilling problem.

[0023] Finally, the method mixes the first fiber and the second fiber, which have clear characteristics and complementary functions, and obtains a cotton-feel composite polyester yarn through spinning. This combination allows a single yarn to contain both a component that provides comfort and a component with heat shrinkage potential. Although it is a yarn preparation method itself and does not involve heat treatment of the fabric, by preparing and mixing in a second fiber with heat shrinkage, it has laid the foundation for the final product to activate this shrinkage property through heat treatment in subsequent processing, thereby achieving an anti-pilling effect. Therefore, the method defined in this technical solution, by preparing and combining these two fibers with specific key functional characteristics, provides a complete technical path for the preparation of composite yarns with both excellent comfort potential and inherent anti-pilling potential.

[0024] Existing technologies typically use chemical finishing or fiber strength modification to mitigate pilling. These methods can be short-lived, environmentally unfriendly, or compromise other performance characteristics. This solution incorporates heat-shrinkable PBT fibers during yarn preparation, creating an anti-pilling mechanism that leverages the fiber's inherent physical properties and is activated by subsequent conventional heat treatment. This "built-in" physical anti-pilling design approach, unlike conventional existing methods, delivers a more durable and environmentally friendly anti-pilling effect.

[0025] Moreover, in terms of improving wearing comfort, the first fiber and the second fiber prepared by this method work together. Due to its special-shaped cross-section and high moisture regain, the first fiber provides the yarn with a good moisture absorption and perspiration foundation and a skin-friendly touch similar to cotton. However, with only the first fiber, the fluffiness and resilience of the yarn may be insufficient. At this time, the addition of the second fiber plays an important supplementary role. PBT fiber itself has low bending stiffness and a soft touch. More importantly, its thermal shrinkage is not only used to prevent pilling in subsequent fabric processing, but also makes the internal structure of the yarn fluffy at the microscopic level, increasing the volume and internal air content of the fabric, which helps to improve warmth retention and softness, and improves the close-fitting feel that may be produced by pure PET fiber. Therefore, it is the combination of the physical properties of these two fibers in the yarn microstructure that together brings a more comprehensive wearing comfort than a single component.

[0026] The synergistic effect of the first and second fibers is also crucial in addressing pilling. While the first fibers provide comfort, as short fibers, their ends can still form hairiness and pilling when subjected to friction. The thermal shrinkage of the second fibers does not act independently but directly impacts the internal structure of the composite yarn, particularly the first fibers blended into it. During the subsequent heat treatment of the fabric, the second fibers shrink, generating an inward tension that tightly binds and secures the fiber ends of the relatively non-shrinkable first fibers within the yarn, or wraps them within the shrinking PBT fibers. This shrinkage and anchoring effect effectively reduces the chance of the first fiber ends being exposed and entangled, forming pills. Therefore, the anti-pilling effect is achieved through the interaction between the PBT and PET fibers in the specific blend structure, triggered by heat treatment, rather than relying solely on the inherent properties of PBT. This synergistic mechanism makes the anti-pilling effect more effective and long-lasting, while also avoiding the compromise in comfort caused by excessive use of PBT.

[0027] In Technical Solution 2, it is specified that the polyethylene terephthalate raw material for the first fiber is "spinning-grade" chips, the hygroscopic modifier is "hygroscopic polyester functional masterbatch", and the polybutylene terephthalate raw material for the second fiber is "spinning-grade" chips. These limitations ensure that the raw materials used meet the basic requirements of the melt spinning process, such as having appropriate melt viscosity, purity, and thermal stability, thereby ensuring the smooth progress of the fiber preparation process and the stability and repeatability of product quality. In particular, the use of "hygroscopic polyester functional masterbatch" as a modifier is clearly specified, and the specific technical means for achieving a high moisture regain of the first fiber are pointed out, making the technical solution clearer and more specific, easier for those skilled in the art to understand and implement, and helping to stably obtain the first fiber with the expected comfort properties.

[0028] In Technical Solution 3, the range of key melt spinning and stretching process parameters for preparing the first fiber is specifically defined. The defined melt extrusion temperature, spinning temperature, spinning speed, stretching water tank temperature, and pre-stretching and main stretching ratios are key process conditions to ensure that the first fiber can stably form the desired special-shaped cross-sectional morphology, obtain appropriate molecular chain orientation and crystallinity, and ultimately possess stable physical properties. For example, appropriate spinning temperature and speed contribute to the stable formation of special-shaped spinneret holes; precisely controlled stretching ratio and temperature determine the mechanical properties and microstructure of the fiber, which in turn affects its hygroscopicity and subsequent processing performance. Precise control of these parameters is an important guarantee for achieving the expected function of the first fiber and ensuring the stability of subsequent product quality.

[0029] Technical Solution 4 specifically defines the range of key melt spinning and stretching process parameters for preparing the second fiber. The core purpose of the defined melt extrusion temperature, spinning temperature, spinning speed, stretching tank temperature, and pre-draw and main draw ratios is to precisely control the microstructure of the prepared PBT fiber, especially the proportion of its amorphous region and the relaxation state of the molecular chain, thereby ensuring that the fiber can undergo significant and controllable shrinkage during subsequent heat treatment at lower temperatures. This is different from the process parameters for preparing ordinary low-shrinkage PBT fibers. By optimizing and strictly controlling these parameters, a second fiber with the expected thermal shrinkage potential can be stably obtained. This is the technical key to the present invention's use of the physical properties of PBT to achieve anti-pilling function.

[0030] In technical solution five, the specific irregular cross-sectional shape of the first fiber and the more preferred range of moisture regain are defined. Specific irregular cross-sectional shapes, such as a four-leaf clover shape, generally have a larger specific surface area and a more developed groove structure than simple irregular shapes, which can more effectively promote capillary action, accelerate the absorption, conduction and evaporation of sweat, and thus provide better moisture absorption and perspiration performance and a dry and refreshing skin feel. Further narrowing the preferred range of moisture regain to 1.5%-2.5% is based on ensuring a significant skin-friendly and cotton-like feel, while further balancing the relationship between hygroscopicity and other fiber properties, such as wet and dry strength, dimensional stability, and dyeing uniformity, in order to achieve the best overall comfort experience and wearing performance.

[0031] In technical solution six, the fineness and length range of the first fiber and the second fiber are limited. The use of thinner fibers such as 0.5-1.5 denier can help improve the softness of the final yarn and reduce its bending stiffness, so that the fabric feels more delicate and fluffy, and is more comfortable and close-fitting when worn. Limiting the fiber length to the range of 38-76mm is a comprehensive consideration of the fiber's spinnability, cohesion, and similarity to cotton fiber length. The right length can ensure that the fiber is not prone to excessive short fibers and defects during the mixing and spinning process, ensuring uniform yarn dryness and strength, and is also conducive to obtaining a plump feel similar to natural fibers. Unifying or coordinating the specifications of the two fibers, especially the length, is crucial to ensuring mixing uniformity and the stability of the spinning process.

[0032] Technical Solution 7 defines the preferred weight ratio of the first and second fibers when mixed. This ratio is based on the critical balance point for achieving the dual goals of comfort and anti-pilling properties. A higher proportion of the first fiber ensures that the yarn and fabric can fully demonstrate their comfortable properties such as softness, skin-friendliness, moisture absorption and perspiration wicking. At the same time, the second fiber is guaranteed to occupy a sufficient proportion so that during subsequent heat treatment, the internal stress generated by the shrinkage of the PBT fiber is sufficient to effectively restrain the PET fiber hairiness, thereby achieving a significant anti-pilling effect. If the PBT ratio is too low, the anti-pilling effect is not obvious; if the ratio is too high, it may affect the softness and cost of the fabric, and may even cause excessive shrinkage. Therefore, this specific, relatively narrow ratio range is the technical key to achieving the optimal synergistic effect of the two properties.

[0033] In technical solution eight, the spinning step is limited to a specific Siro compact spinning process. Compared with traditional ring spinning, the Siro compact spinning technology adds a suction and condensation device after the drafting zone, so that the fiber strands are effectively condensed and controlled before twisting, and the fibers are more parallel, straight, and tightly held. This directly leads to the spun yarn having the advantages of very little hairiness, high strength, uniform yarn length, and smooth surface. The use of this process in the present invention first directly reduces the hairiness of the yarn itself, reducing the basis for pilling from the source; secondly, the compact yarn structure formed is more conducive to the PBT fiber to produce a stronger binding force on the internal fibers during subsequent shrinkage. Therefore, the application of the Siro compact spinning process not only improves the overall quality and appearance of the yarn, but also produces a synergistic enhancement effect with the heat shrinkage and anti-pilling mechanism of the PBT fiber, so that the anti-pilling performance of the final fabric reaches an extremely excellent level.

[0034] Technical Solution 9 defines the imperial count range for the final cotton-feel composite polyester yarn. Imperial count is a measure of yarn fineness, with 50S-60S belonging to the medium-to-high yarn count range. Selecting this count range signifies the present invention's goal of producing finer, higher-end yarns. Fabrics made from yarns of this fineness are typically light, soft, delicate, and have excellent drape. This better reflects the comfort provided by the primary fiber and meets consumer demand for high-quality, lightweight apparel.

[0035] Technical Solution 10 provides a method for preparing a cotton-feel polyester fabric. The method uses the composite polyester fiber obtained by the method for preparing a cotton-feel composite polyester yarn described in any of the above technical solutions as raw material. After weaving the resulting grey fabric, the fabric is subjected to a dyeing and finishing process including at least one heat treatment. The heat treatment step is specified to be performed under conditions sufficient to shrink the second fibers in the cotton-feel composite polyester yarn. This heat treatment shrinks the second fibers and ultimately improves the anti-pilling properties of the cotton-feel polyester fabric. The heat treatment activation mechanism defined in this method is based on the physical properties of the fibers, rather than chemical treatment. Therefore, the effect is more durable and environmentally friendly, addressing the shortcomings of existing chemical anti-pilling finishes, which suffer from short-term effects or environmental issues.

[0036] In Technical Solution 11, the specific weaving structure of the fabric in Technical Solution 10 is defined. When knitting is used, a polyester-covered polyester-spandex plain weave structure is preferred, and it is clear that the veil uses the cotton-feel composite polyester yarn of the present invention, and the base yarn uses PBT filaments. This specific fabric structure design has clear technical advantages: the cotton-feel composite polyester yarn with excellent performance is placed on the surface of the fabric (veil layer), so that it can directly contact the skin or be exposed to the external environment, thereby maximizing its moisture absorption and perspiration, soft and skin-friendly comfort properties and excellent anti-pilling performance. At the same time, the base yarn uses PBT filaments with good elasticity, which can give the entire fabric good stretch recovery properties, increase wearing comfort and freedom of movement. This functional zoning structural design optimizes the combination and best display of the fabric's comfort, anti-pilling, elasticity and other properties.

[0037] Technical Solution 12 further refines the dyeing and finishing steps in Technical Solution 10, defining a complete process flow including degreasing and shrinking, grey fabric setting, dyeing, reduction cleaning, final product shaping, and drying, and limiting the specific temperature ranges for three key heat treatment processes. These specific processes and precise temperature control are key guarantees for achieving and optimizing the final technical effect. While cleaning the fabric surface, the degreasing and shrinking process utilizes relatively mild, moist heat conditions to induce initial relaxation and partial shrinkage of the PBT fibers, preparing for subsequent, more significant shrinkage. The grey fabric setting process is the core link in the present invention that utilizes the thermal shrinkage of PBT to achieve an anti-pilling effect. At this high temperature, the PBT fibers undergo sufficient and significant shrinkage, strongly binding the PET hairiness, while the high temperature also stabilizes the fabric structure. The final product shaping process is carried out after dyeing, using relatively low temperatures to finish the fabric surface, eliminate wrinkles, give the fabric final dimensional stability and a smooth appearance, and may further consolidate the shrinkage state of the PBT. By precisely defining these three key heat treatment steps and their temperature ranges, the shrinkage process of PBT fiber is ensured to be controllable and effective, achieving excellent anti-pilling effects while avoiding problems such as insufficient shrinkage, excessive shrinkage, stiff feel, or dimensional instability caused by excessively high or low temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 is a schematic cross-sectional view of a first fiber prepared in an embodiment of the present invention;

[0040] Figure 2Schematic diagram of the cotton-feel composite polyester yarn prepared in an embodiment of the present invention before and after heat treatment. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are preferred embodiments of the present invention and should not be regarded as excluding other embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] In the claims, description and drawings of the present invention, if the terms "include", "have" and their variations are used, they are intended to mean "including but not limited to".

[0043] Definition of terms

[0044] To facilitate understanding of the present invention, some terms used in the specification and claims are defined here:

[0045] Spinning-grade polyethylene terephthalate chips (or polybutylene terephthalate chips) refer to polymer chips that meet specific physical and chemical specifications, such as intrinsic viscosity, melting point, color, impurity content, and moisture content, making them suitable for use in the melt-spinning process to produce polyester fibers. Those skilled in the art will understand this definition based on conventional industry standards and production requirements. For example, the intrinsic viscosity is typically within a certain range to ensure good melt flowability and spinnability.

[0046] Hygroscopic polyester functional masterbatch: A granular additive made by pre-dispersing one or more active additives (such as hydrophilic polymers, porous materials, or additives that introduce hydrophilic groups) into a polyester (usually compatible with the base resin) carrier resin at a high concentration to improve the final fiber's hygroscopic properties. During the melt spinning process, this masterbatch is mixed with the base polyester chips in a specific ratio to impart hygroscopic properties to the final fiber.

[0047] Blending refers to the process of physically mixing two or more different polymer materials (e.g., chips) or polymers with additives (e.g., masterbatches) in a molten state or before melting, in order to obtain a material with uniform properties or specific composite properties. In this context, this refers to mixing PET chips with a hygroscopic polyester functional masterbatch before or during melt extrusion.

[0048] Special-shaped cross section: refers to the shape of the fiber cross section is not circular or approximately circular, but has a specific non-circular profile, such as cross, Y-shaped, triangle, flat, hollow or as shown in the attached Figure 1The four-leaf clover shape shown in the figure is usually used to give the fiber special functions, such as increasing the specific surface area, changing the gloss, improving moisture conductivity, improving cohesion, etc.

[0049] Melt spinning: This refers to a spinning method in which fiber-forming polymers (such as PET and PBT chips) are heated and melted to a viscous state. After being precisely metered by a metering pump, the melt is forced through a spinneret, where it is extruded from the spinneret's micropores to form a fine stream. After leaving the spinneret, the stream is cooled (e.g., in air or a water bath) and solidified to form nascent fibers. This is the primary method for producing thermoplastic synthetic fibers such as polyester.

[0050] Primary fiber: refers to the fiber that has not yet been stretched after the melt stream leaves the spinneret micropores and cools and solidifies. At this time, the fiber's molecular chain orientation and crystallinity are usually low, and its mechanical properties are also poor.

[0051] Stretching: This refers to the process of applying tension along the axial direction of spun or pre-oriented fibers, causing them to plastically deform. This aligns the macromolecular chains within the fibers along the axial direction and may induce crystallization. Stretching is a key process for improving mechanical properties such as fiber strength and modulus.

[0052] Heat setting refers to the process of heat-treating fibers or fabrics under a certain tension (or relaxation) at a specific temperature (usually above the glass transition temperature but below the melting point). Its main purpose is to stabilize the internal structure of the fiber formed by stretching, eliminate internal stress, improve dimensional stability, and fix the shape (such as curl). It may also affect the crystallinity and dyeing properties of the fiber.

[0053] Heat shrinkage refers to the property of a fiber or yarn to shrink in its length after being treated in a heat medium (such as hot water or hot air) at a specific temperature. In this context, this specifically refers to the physical property of the second fiber (PBT staple fiber) that results in significant length shrinkage during subsequent fabric dyeing and finishing heat treatments.

[0054] Moisture regain refers to the percentage of moisture absorbed by a fiber material to its dry weight under standard atmospheric conditions (usually temperature 20±2°C, relative humidity 65±2%). It is an important indicator for measuring the fiber's moisture absorption capacity.

[0055] Denier: An indicator of fiber thickness. The unit "D" used in this invention refers to denier, which is defined as the weight of 9,000 meters of fiber. The smaller the denier value, the finer the fiber.

[0056] Siro compact spinning process: An improved ring spinning technology, which is characterized by the use of double-root sliver feeding and the provision of a suction and condensation zone after the front roller output and before twisting. This allows the fibers to be effectively bundled and controlled before twisting, thereby significantly reducing yarn hairiness and improving yarn strength, wear resistance and surface finish.

[0057] Imperial Count: An indirect counting system used to indicate the fineness of cotton staple yarn. It is defined as the number of 840 yards (768 meters) of yarn per pound (453.6 grams) at a specified moisture regain. Higher counts indicate finer yarns.

[0058] Weaving: refers to the process of interweaving or stringing yarns together to form a fabric. It mainly includes two categories: weaving (interweaving warp and weft yarns) and knitting (stringing coils together).

[0059] Greige fabric: refers to the original state of the fabric that has just come off the loom or knitting machine and has not yet undergone subsequent processing such as bleaching, dyeing, printing, and finishing.

[0060] Dyeing and finishing: refers to a series of chemical and physical processing processes on grey fabrics, including pre-treatment (such as desizing, scouring, bleaching, mercerizing), dyeing, printing and finishing (such as shaping, softening, wrinkle resistance, waterproofing, flame retardancy, anti-pilling, etc.), with the aim of giving the fabric the desired appearance, feel and performance.

[0061] Polyester-spandex plain weave: A common knit fabric construction, typically consisting of a face yarn (forming the loops on the front of the fabric) made of one yarn (in this case, a cotton-feel composite polyester yarn) and a ground yarn (forming the loops on the back or structural foundation) made of another yarn (in this case, PBT filament), woven in a plain (or modified plain) weave. The inclusion of "spandex" in the name is customary and does not necessarily imply the inclusion of spandex. The specific structure is determined by the materials and weave of the face and ground yarns.

[0062] Filament: refers to a single fiber of infinite or very long length, such as a continuous filament directly extruded from a spinneret. It is the opposite of short fibers that have been cut.

[0063] Technical Solution Overview

[0064] The present invention aims to provide a method for preparing a cotton-feel composite polyester yarn and a method for preparing a cotton-feel polyester fabric prepared using the yarn, so as to improve the technical problem in the prior art that the cotton-feel polyester fabric is difficult to achieve a good balance between wearing comfort and anti-pilling performance.

[0065] Among them, the preparation method of the cotton-feel composite polyester yarn includes the following steps: preparing the first fiber: blending the polyethylene terephthalate raw material with the hygroscopic modifier, and forming the first spun fiber with a special cross-section by melt spinning; the first spun fiber is stretched, heat-set and cut to obtain the first fiber; the moisture regain of the first fiber is between 1.5% and 3%; preparing the second fiber: forming the second spun fiber by melt spinning the polybutylene terephthalate raw material; the second spun fiber is stretched, heat-set and cut to obtain the second fiber with heat shrinkage; the first fiber and the second fiber are mixed and spun to obtain the cotton-feel composite polyester yarn.

[0066] The preparation method of the cotton-feel polyester fabric comprises the following steps: using the cotton-feel composite polyester yarn prepared by the above-mentioned preparation method of the cotton-feel composite polyester yarn as a raw material to weave a grey cloth; and performing dyeing and finishing on the grey cloth, wherein the dyeing and finishing includes at least one heat treatment step, and the process parameters of the heat treatment step are sufficient to shrink the second fibers in the cotton-feel composite polyester yarn.

[0067] Among them, as a preferred embodiment, in the step of preparing the first fiber, the polyethylene terephthalate raw material is spinning-grade polyethylene terephthalate chips, and the hygroscopic modifier is a hygroscopic polyester functional masterbatch; and in the step of preparing the second fiber, the polybutylene terephthalate raw material is spinning-grade polybutylene terephthalate chips.

[0068] As a preferred embodiment, the melt spinning in the step of preparing the first fiber includes: melt extrusion at a temperature of 240°C to 290°C, and spinning through a spinneret with special-shaped holes at a spinning temperature of 240°C to 290°C and a spinning speed of 1200m / min to 1500m / min; and the stretching includes: in a stretching water tank at 60°C to 85°C, with a pre-stretching ratio of 1.05 to 1.10 and a main stretching ratio of 1.5 to 3.5.

[0069] As a preferred embodiment, the melt spinning in the step of preparing the second fiber includes: melt extrusion at a temperature of 240°C to 280°C, and spinning through a porous spinneret at a spinning temperature of 230°C to 270°C and a spinning speed of 1200m / min to 1500m / min; and the stretching includes: in a stretching water tank at 60°C to 85°C, with a pre-stretching ratio of 1.05 to 1.10 and a main stretching ratio of 1.5 to 3.5.

[0070] As a preferred embodiment, the special-shaped cross-section of the first fiber is selected from a cross shape, a Y shape, or a four-leaf clover shape; and the moisture regain of the first fiber is in the range of 1.5% to 2.5%.

[0071] As a preferred embodiment, the fineness of the first fiber is 0.5D to 1.5D, and the length thereof is 38mm to 76mm; and the fineness of the second fiber is 0.5D to 1.5D, and the length thereof is 38mm to 76mm.

[0072] As a preferred embodiment, in the step of spinning the mixed first fiber and the second fiber, the proportion of the first fiber is 65% to 75% by weight, and the proportion of the second fiber is 25% to 35% by weight.

[0073] As a preferred embodiment, the English count of the cotton-feel composite polyester yarn is 50S to 60S.

[0074] In addition, in the preparation method of cotton-feel polyester fabric, as a preferred embodiment, the weaving is knitting, and the formed grey cloth structure is a polyester-covered polyester-spandex plain weave structure, wherein the face yarn is made of the cotton-feel composite polyester yarn, and the base yarn is made of polybutylene terephthalate filament.

[0075] As a preferred embodiment, the dyeing and finishing treatment includes degreasing and shrinking, grey cloth setting, dyeing, reduction cleaning, finished product setting and drying processes in sequence; the degreasing and shrinking process is carried out at a temperature of 95°C to 105°C; the grey cloth setting process is carried out at a temperature of 180°C to 195°C; and the finished product setting process is carried out at a temperature of 145°C to 155°C.

[0076] One of the key components of the cotton-feel composite polyester yarn of the present invention is the first fiber, i.e., a shaped hygroscopic polyethylene terephthalate (PET) staple fiber. The first fiber is prepared by blending polyethylene terephthalate raw material with a hygroscopic modifier, such as a hygroscopic polyester functional masterbatch, and then forming a primary fiber with a shaped cross-section through melt spinning, and then undergoing processes such as stretching, heat setting, and cutting. Figure 1The schematic cross-section of the first fiber shown shows a "special-shaped cross-section," or four-leaf clover-shaped design, which significantly increases the fiber's specific surface area and creates numerous fine grooves and pores on the fiber surface and between fibers. This unique physical structure greatly enhances the capillary effect, allowing the fiber to quickly absorb and conduct and diffuse sweat and moisture from the skin along the fiber axis and along the surface grooves, thereby imparting excellent moisture-wicking properties to the fabric, resulting in a dry, non-sticky wear experience. Furthermore, through the introduction of a hygroscopic modifier and process control, the first fiber exhibits a moisture regain range of 1.5% to 3%, significantly higher than the typical moisture regain of approximately 0.4% for conventional PET fibers. This higher moisture regain allows the fiber to absorb more water molecules, bringing its physical properties closer to those of natural fibers like cotton. This significantly improves the inherent dryness and airtightness inherent in traditional polyester fibers, imparting a soft, skin-friendly feel to the fiber itself and the final product, commonly known as a "cotton feel." These properties of the first fiber provide the foundation for the composite yarn's excellent wear comfort.

[0077] Another key component of the cotton-feel composite polyester yarn of the present invention is the second fiber, namely the heat-shrinkable polybutylene terephthalate (PBT) staple fiber. The second fiber is prepared from polybutylene terephthalate raw material through processes such as melt spinning, stretching, heat setting and cutting, and its core characteristic is that it is "heat shrinkable". PBT material and PET material have differences in thermophysical properties. PBT has a lower glass transition temperature and is more prone to molecular chain movement and orientation relaxation under specific temperature conditions, thereby exhibiting significant heat shrinkage behavior. Through precise control of the PBT fiber preparation process, the oriented structure formed during the spinning and stretching process can be effectively shrunk under subsequent low-temperature heat treatment, such as heat setting during the fabric dyeing and finishing process. This heat-shrinkage characteristic is the key physical basis for the present invention to achieve anti-pilling function.

[0078] The core effect of the present invention does not simply come from the superposition of the independent properties of the two fibers, but rather from their synergistic effect in the composite yarn. Figure 2 The schematic diagram of the cotton-feel composite polyester yarn structure shown here demonstrates the enhanced wearing comfort achieved by combining the excellent moisture absorption and moisture transport capabilities of the first fiber with the softness created by the lower bending stiffness of the second fiber. Furthermore, when the fabric is heat-treated, the shrinkage of the PBT fibers creates a microscopic, fluffy structure within the yarn, increasing the fabric's air content and volume. This not only enhances warmth retention and softness, but also mitigates the potentially clingy, airtight feel of pure PET fibers, creating a more comprehensive wearing comfort experience.

[0079] In solving the pilling problem, the synergistic effect of the first fiber and the second fiber is particularly critical. As a short fiber product, the fiber ends on the surface of the yarn are easily formed into hairiness when rubbed, and then develop into pilling, which affects the appearance and durability of the fabric. In the present invention, when the fabric made of the composite yarn containing these two fibers undergoes heat treatment during the dyeing and finishing process, such as the attached Figure 2 As shown in the "After Heat Treatment" section, the heat-shrinkable second fiber (PBT) shrinks significantly. Because the PBT fibers are intimately blended with the first fibers, the PBT's shrinkage generates an inward pull, tightly binding and securing the fiber ends of the relatively non-shrinkable first fibers within the yarn, or causing them to become entangled and wrapped by the shrinking PBT fibers. This "shrinkage-anchoring" effect effectively reduces the chances of the first fiber ends migrating to the yarn surface, becoming exposed, or becoming entangled and forming pills. Therefore, the anti-pilling effect is a direct result of the physical interaction between the heat-shrinkage properties of the PBT fibers and the PET fibers in this specific blend structure, generated through thermal stimulation. This inherent, physical anti-pilling mechanism makes the anti-pilling effect more effective and long-lasting, while avoiding the potential compromise in comfort caused by over-reliance on PBT.

[0080] To create a cotton-like composite polyester yarn, these two fibers are blended in a predetermined ratio before spinning. Using the Siro compact spinning process further enhances yarn performance. Siro compact spinning significantly reduces surface hairiness by improving fiber alignment and cohesion, enhancing yarn strength and finish. This not only directly improves the yarn's appearance and feel but also reduces the source of pilling, creating a synergistic effect with the PBT fiber's heat-shrinkage and anti-pilling mechanisms.

[0081] Finally, when using the cotton-feel composite polyester yarn prepared by the present invention to manufacture cotton-feel polyester fabrics, after being woven into grey fabric, the key step lies in the dyeing and finishing process. This dyeing and finishing process must include at least one heat treatment step, and the process parameters of this heat treatment step must be sufficient to effectively shrink the second fiber in the cotton-feel composite polyester yarn. This step is the core link in ensuring that the PBT fiber can exert its heat shrinkage properties and achieve the final anti-pilling performance of the fabric. By precisely controlling the heat treatment temperature and time, the PBT fiber can be ensured to shrink appropriately, achieving excellent anti-pilling effects while avoiding problems such as excessive shrinkage that may cause the fabric to feel stiff or have dimensional instability.

[0082] Examples and Comparative Examples

[0083] The following detailed description of the cotton-feel composite polyester yarn and its preparation method, and the cotton-feel polyester fabric and its preparation method of the present invention is provided through specific examples. It should be understood that these examples are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. Experimental methods in the examples where specific conditions are not specified are generally carried out under conventional conditions or under conditions recommended by the manufacturer. Unless otherwise defined, all technical terms used herein have the same meanings as those commonly understood by those skilled in the art.

[0084] Performance testing method:

[0085] Moisture regain test: Tested in accordance with GB / T 6504-2017 "Test method for moisture regain of chemical fibers".

[0086] Fineness test: Test in accordance with GB / T 14343-2008 "Test method for linear density of synthetic filaments" or GB / T 6503-2017 "Test method for linear density of chemical staple fibers".

[0087] Fiber length test: Tested in accordance with GB / T 14335-2008 "Test method for length of chemical staple fibers".

[0088] Yarn count test: Test in accordance with GB / T 4743-2009 "Determination of linear density (or count) of yarn - Skein method".

[0089] Fabric weight test: Tested in accordance with GB / T 4669-2008 "Textiles - Woven Fabrics - Determination of Mass per Unit Length and Mass per Unit Area".

[0090] Moisture absorption and quick-drying test: The test is conducted in accordance with GB / T 21655.1-2023 "Evaluation of moisture absorption and quick-drying properties of textiles - Part 1: Single combination test method", and the water absorption rate and drying time (or evaporation rate) are recorded.

[0091] Pilling resistance test: Test according to GB / T 4802.2-2008 "Textile fabrics - Determination of propensity to pilling - Part 2: Modified Martindale method" and evaluate the grade (1-5, 5 is the best, 1 is the worst).

[0092] Softness evaluation: A subjective evaluation method is used, with several experienced testers tactilely evaluating the samples. The samples are usually divided into levels such as excellent, good, medium, and poor, or scored on a 5-point scale.

[0093] Example 1

[0094] (1) Preparation of the first fiber:

[0095] Spinning-grade polyethylene terephthalate (PET) chips with an intrinsic viscosity of 0.64 dl / g were uniformly blended with 15% (by weight) of hygroscopic polyester functional masterbatch (the carrier was PET, containing hydrophilic copolyester).

[0096] The blended materials were fed into a screw extruder and melt-extruded at 285°C.

[0097] After being metered by a metering pump, the melt passes through a spinneret having four-leaf clover-shaped holes and is spun at a spinning temperature of 285° C. and a spinning speed of 1350 m / min to form nascent fibers.

[0098] The as-spun fibers were stretched in a stretching water bath at 75°C with a pre-stretch ratio of 1.07 and a main stretch ratio of 2.5.

[0099] The stretched fibers are then crimped.

[0100] The crimped fibers were subjected to tension heat setting (temperature 140°C) and oven relaxation heat setting (temperature 160°C) in sequence.

[0101] The heat-set fibers were cut to obtain first fibers with a fineness of 1.0D, a length of 39 mm, and a four-leaf clover-shaped cross section. Testing showed that the moisture regain was 2.0%.

[0102] (2) Preparation of the second fiber:

[0103] Spinning-grade polybutylene terephthalate (PBT) chips with an intrinsic viscosity of 1.0 dl / g were fed into a screw extruder and melt-extruded at 260°C.

[0104] After being metered by a metering pump, the melt passes through a circular multi-hole spinneret and is spun at a spinning temperature of 250° C. and a spinning speed of 1350 m / min to form nascent fibers.

[0105] The as-spun fibers were stretched in a stretching water bath at 70°C with a pre-stretch ratio of 1.07 and a main stretch ratio of 2.5.

[0106] The stretched fibers are then crimped.

[0107] The crimped fibers were subjected to tension heat setting (temperature 130°C) and oven relaxation heat setting (temperature 150°C) in sequence.

[0108] The heat-set fibers were cut to obtain heat-shrinkable second fibers having a fineness of 1.0D and a length of 39 mm.

[0109] (3) Preparation of cotton-feel composite polyester yarn:

[0110] The first fibers obtained in step 1 and the second fibers obtained in step 2 are mixed in a weight ratio of 70%:30%.

[0111] The mixed fibers are processed through the front-end processes of opening, carding, drawing, roving, etc.

[0112] The siro compact spinning process is used to spin the yarn into a cotton-feel composite polyester yarn with a British count of 55S.

[0113] Winding is carried out to remove yarn defects.

[0114] (4) Preparation of cotton-feel polyester fabric:

[0115] The 55S cotton-feel composite polyester yarn obtained in step 3 is used as the face yarn, and the 50D PBT filament is used as the base yarn. The 36-needle single-sided circular machine is used for knitting. The fabric structure is a polyester-covered polyester-spandex plain weave fabric with a gram weight of about 210g / m 2 .

[0116] The process of dyeing and finishing the grey fabric is as follows:

[0117] Oil removal and shrinkage: carried out in an overflow dyeing machine, adding 1g / L of degreasing agent, bath ratio 1:10, and treating at 100℃ for 30min.

[0118] Grey cloth setting: It is carried out on a stenter setting machine with the temperature set at 188°C, overfeed of 25%, and a speed of 28m / min.

[0119] Dyeing: Use disperse dyes for dyeing, add 0.5g / L glacial acetic acid and 0.6g / L dispersant, the dye concentration is determined according to the required color, the bath ratio is 1:8, and keep warm at 125℃ for 45min.

[0120] Reduction cleaning: Use hydrosulfite, soda ash, etc. for reduction cleaning to remove floating color.

[0121] Finished product shaping: After adjusting the pH value, final shaping is carried out on a stenter setting machine at a temperature of 150°C and a speed of 20m / min.

[0122] drying.

[0123] (5) Performance testing:

[0124] The final fabric is subjected to performance tests, and its water absorption rate, drying time, softness evaluation, and pilling resistance level are recorded.

[0125] Example 2

[0126] (1) Preparation of the First Fiber: The same method as in Example 1 was used, except that the proportion of the hygroscopic polyester functional masterbatch added (e.g., reduced to 5%) and / or the process parameters were adjusted so that the moisture regain of the final first fiber was 1.5%. Other parameters (fineness 1.0D, length 39 mm, four-leaf clover cross-section) remained unchanged.

[0127] (2) Preparation of the second fiber: same as in Example 1.

[0128] (3) Preparation of cotton-feel composite polyester yarn: same as Example 1 (mixing ratio 70 / 30, 55S siro compact spinning).

[0129] (4) Preparation of cotton-feel polyester fabric: same as in Example 1.

[0130] (5) Performance test: Same as Example 1.

[0131] Example 3 (upper limit of moisture regain)

[0132] (1) Preparation of the First Fiber: The same method as in Example 1 was used, except that the proportion of the hygroscopic polyester functional masterbatch added (e.g., increased to 20%) and / or the process parameters were adjusted so that the moisture regain of the resulting first fiber was 3.0%. Other parameters (fineness 1.0D, length 39 mm, four-leaf clover cross-section) remained unchanged.

[0133] (2) Preparation of the second fiber: same as in Example 1.

[0134] (3) Preparation of cotton-feel composite polyester yarn: same as Example 1 (mixing ratio 70 / 30, 55S siro compact spinning).

[0135] (4) Preparation of cotton-feel polyester fabric: same as in Example 1.

[0136] (5) Performance test: Same as Example 1.

[0137] Example 4

[0138] (1) Preparation of the first fiber: same as in Example 1 (moisture regain 2.0%).

[0139] (2) Preparation of the second fiber: same as in Example 1.

[0140] (3) Preparation of cotton-feel composite polyester yarn: The first fiber and the second fiber were mixed in a weight ratio of **65%:**35%**. Other conditions were the same as those in Example 1 (55S Siro compact spinning).

[0141] (4) Preparation of cotton-feel polyester fabric: same as in Example 1.

[0142] (5) Performance test: Same as Example 1.

[0143] Example 5

[0144] (1) Preparation of the first fiber: same as in Example 1 (moisture regain 2.0%).

[0145] (2) Preparation of the second fiber: same as in Example 1.

[0146] (3) Preparation of cotton-feel composite polyester yarn: The first fiber and the second fiber were mixed in a weight ratio of **75%:**25%**. Other conditions were the same as those in Example 1 (55S Siro compact spinning).

[0147] (4) Preparation of cotton-feel polyester fabric: same as in Example 1.

[0148] (5) Performance test: Same as Example 1.

[0149] Example 6

[0150] (1) Preparation of the first fiber: The spinning and stretching parameters were adjusted to obtain a first fiber with a fineness of 0.5D and a length of 38 mm (four-leaf clover cross section, moisture regain 2.0%).

[0151] (2) Preparation of the second fiber: The spinning and stretching parameters were adjusted to obtain a second fiber with a fineness of 0.5D and a length of 38 mm.

[0152] (3) Preparation of cotton-feel composite polyester yarn: same as Example 1 (mixing ratio 70 / 30, 55S siro compact spinning).

[0153] (4) Preparation of cotton-feel polyester fabric: same as in Example 1.

[0154] (5) Performance test: Same as Example 1.

[0155] Example 7

[0156] (1) Preparation of the first fiber: The spinning and stretching parameters were adjusted to obtain a first fiber with a fineness of 1.5D and a length of 76 mm (four-leaf clover cross section, moisture regain 2.0%).

[0157] (2) Preparation of the second fiber: The spinning and stretching parameters were adjusted to obtain a second fiber with a fineness of 1.5D and a length of 76 mm.

[0158] (3) Preparation of cotton-feel composite polyester yarn: same as Example 1 (mixing ratio 70 / 30, 55S siro compact spinning).

[0159] (4) Preparation of cotton-feel polyester fabric: same as in Example 1.

[0160] (5) Performance test: Same as Example 1.

[0161] Example 8

[0162] (1) Preparation of the first fiber: same as in Example 1.

[0163] (2) Preparation of the second fiber: same as in Example 1.

[0164] (3) Preparation of cotton-feel composite polyester yarn: A cotton-feel composite polyester yarn with an imperial count of 50S was spun using a Siro compact spinning process. Other conditions were the same as in Example 1 (mixing ratio 70 / 30).

[0165] (4) Preparation of cotton-feel polyester fabric: 50S composite yarn was used as the face yarn, and the rest was the same as in Example 1.

[0166] (5) Performance test: Same as Example 1.

[0167] Example 9

[0168] (1) Preparation of the first fiber: same as in Example 1.

[0169] (2) Preparation of the second fiber: same as in Example 1.

[0170] (3) Preparation of cotton-feel composite polyester yarn: A cotton-feel composite polyester yarn with an imperial count of 60S was spun using a Siro compact spinning process. Other conditions were the same as in Example 1 (mixing ratio 70 / 30).

[0171] (4) Preparation of cotton-feel polyester fabric: 60S composite yarn was used as the face yarn, and the rest was the same as in Example 1.

[0172] (5) Performance test: Same as Example 1.

[0173] Comparative Example 1

[0174] (1) Preparation of fibers: Only ordinary PET staple fibers were prepared, using a circular cross-section spinneret, without adding hygroscopic masterbatch, with a moisture regain of approximately 0.4%, a fineness of 1.5D, and a length of 39 mm.

[0175] (2) Yarn preparation: 100% of the ordinary PET staple fibers were used to spin 55S yarns using a Siro compact spinning process.

[0176] (3) Fabric preparation: The 55S ordinary PET yarn was used as the face yarn, and the rest was the same as in Example 1.

[0177] (4) Performance test: Same as Example 1.

[0178] Comparative Example 2

[0179] (1) Preparation of fibers: The first fibers (shaped hygroscopic PET, moisture regain 2.0%) were prepared in the same manner as in Example 1.

[0180] (2) Yarn preparation: 100% of the first fiber is used to spin 55S yarn using a Siro compact spinning process.

[0181] (3) Fabric preparation: The 55S yarn was used as the face yarn, and the rest was the same as in Example 1.

[0182] (4) Performance test: Same as Example 1.

[0183] Comparative Example 3

[0184] (1) Preparation of the first fiber: Prepare ordinary circular cross-section PET short fibers (moisture regain 0.4%, fineness 1.0D, length 39 mm).

[0185] (2) Preparation of the second fiber: The second fiber (heat-shrinkable PBT) was prepared in the same manner as in Example 1.

[0186] (3) Preparation of cotton-feel composite polyester yarn: Ordinary PET and heat-shrinkable PBT were mixed at a ratio of 70 / 30 to produce 55S siro-compact yarn.

[0187] (4) Fabric preparation: The composite yarn is used as the face yarn, and the rest is the same as in Example 1.

[0188] (5) Performance test: Same as Example 1.

[0189] Comparative Example 4

[0190] (1) Preparation of the first fiber: The first fiber (shaped hygroscopic PET, moisture regain 2.0%) was prepared in the same manner as in Example 1.

[0191] (2) Preparation of the second fiber: prepare ordinary, non-heat-shrinkage PBT short fibers (for example, by adjusting the heat setting process to achieve low shrinkage), with the same fineness and length as in Example 1.

[0192] (3) Preparation of cotton-feel composite polyester yarn: 55S siro compact yarn was spun by mixing shaped hygroscopic PET and non-heat shrinkage PBT at a ratio of 70 / 30.

[0193] (4) Fabric preparation: The composite yarn is used as the face yarn, and the rest is the same as in Example 1.

[0194] (5) Performance test: Same as Example 1.

[0195] Comparative Example 5

[0196] (1) Preparation of the first fiber: same as in Example 1.

[0197] (2) Preparation of the second fiber: same as in Example 1.

[0198] (3) Preparation of cotton-feel composite polyester yarn: The two fibers were mixed at a ratio of 70 / 30 and spun into 55S yarn using a conventional ring spinning process.

[0199] (4) Fabric preparation: The ring-spun composite yarn is used as the face yarn, and the rest is the same as in Example 1.

[0200] (5) Performance test: Same as Example 1.

[0201] Comparative Example 6

[0202] (1) Preparation of the first fiber: same as in Example 1.

[0203] (2) Preparation of the second fiber: same as in Example 1.

[0204] (3) Preparation of cotton-feel composite polyester yarn: same as Example 1 (70 / 30, 55S siro compact spinning).

[0205] (4) Fabric preparation: Weaving is the same as in Example 1.

[0206] (5) Dyeing and finishing: Same as in Example 1, the temperature of the grey fabric was lowered to 150°C (lower than the temperature required for effective shrinkage of PBT).

[0207] (6) Performance test: Same as Example 1.

[0208] Performance test results

[0209] To verify the beneficial effects of the technical solution of the present invention, the final cotton-feel polyester fabrics prepared in Examples 1-9 and Comparative Examples 1-6 were subjected to performance tests using the same testing methods as described above. The specific test results are summarized in Table 1 below.

[0210] Table 1: Test results of fabric performance of Examples and Comparative Examples:

[0211]

[0212]

[0213] From the test results in Table 1 we can see that:

[0214] 1. The examples of the present invention significantly outperformed the comparative examples: The fabrics prepared in Examples 1-9 exhibited excellent comfort indicators such as water absorption, evaporation rate, and softness (water absorption generally exceeding 190%, evaporation rate exceeding 0.30 g / h, and softness exceeding 4.0 points). Furthermore, their pilling resistance reached a grade of 4 or better. This demonstrates that the present invention successfully achieves a good balance between wearing comfort and pilling resistance.

[0215] 2. The comparative examples verify the necessity of key technical features:

[0216] Comparative Example 1 (ordinary PET) performed poorly in all indicators, demonstrating the necessity of using specific fibers in the present invention. Comparative Example 2 (using only the first fiber) had good comfort indicators but poor anti-pilling rating, demonstrating the key role of the second fiber (heat-shrink PBT) in achieving the anti-pilling effect. Comparative Example 3 (ordinary PET + heat-shrink PBT) had improved anti-pilling performance but poor comfort indicators, demonstrating the key role of the first fiber (shaped hygroscopic PET) in achieving comfort. Comparative Example 4 (comfortable PET + non-shrink PBT) had good comfort but poor anti-pilling performance, which in turn proved that the "heat shrinkage" of the second fiber was the fundamental reason for achieving the anti-pilling effect. Comparative Example 5 (ordinary ring spinning) had a significantly lower anti-pilling rating compared to Example 1, demonstrating the synergistic enhancement effect of the Siro compact spinning process and the fiber combination of the present invention. Comparative Example 6 (insufficient heat treatment) had a poor anti-pilling rating, demonstrating that a sufficient heat treatment step in the dyeing and finishing process is crucial for activating PBT shrinkage and achieving the anti-pilling effect.

[0217] 3. Effects of Internal Parameter Variations in Examples: The results of Examples 2-9 demonstrate that by adjusting the moisture regain of the first fiber, the blend ratio of the two fibers, fiber fineness and length, yarn count, and process parameters, the performance profile of the final fabric can be controlled within a certain range, while maintaining a good balance between comfort and pilling resistance. This demonstrates the stability and applicability of the technical solution of the present invention. For example, appropriately increasing the PBT ratio (Example 4) further improves pilling resistance, but may slightly affect softness; increasing the moisture regain of the first fiber (Example 3) maximizes comfort.

[0218] In summary, by comparing and analyzing the performance test results of the embodiments and comparative examples, it is fully demonstrated that the cotton-feel composite polyester yarn and its preparation method, the cotton-feel polyester fabric and its preparation method provided by the present invention, by adopting a specific combination of shaped hygroscopic PET fiber and heat-shrinkable PBT fiber, and combining with optimized spinning and dyeing and finishing heat treatment processes, can significantly improve the wearing comfort (moisture absorption, quick drying, softness, skin-friendliness) of the cotton-feel polyester fabric, while giving it excellent and lasting anti-pilling performance, successfully solving the technical problem that the existing technology is difficult to balance these two aspects of performance, and has significant beneficial effects.

[0219] The above description and embodiments are intended to explain the scope of protection of the present invention, but do not constitute a limitation thereto. Modifications, equivalent substitutions, or other improvements to the embodiments of the present invention or portions thereof that can be obtained by a person of ordinary skill in the art through logical analysis, reasoning, or limited experimentation based on the teachings of the present invention or the above embodiments, combined with common knowledge, ordinary technical knowledge in the field, and / or prior art, should all be included within the scope of protection of the present invention.

Claims

1. A method for preparing a cotton-feel composite polyester yarn, characterized in that: The following steps are involved: Preparing a first fiber: blending a polyethylene terephthalate raw material with a hygroscopic modifier and forming a first spun fiber with a special-shaped cross-section by melt spinning; The first spun fiber is stretched, heat-set, and cut to obtain the first fiber; the moisture regain of the first fiber is between 1.5% and 3%; Preparation of the second fiber: melt spinning the polybutylene terephthalate raw material to form a second spun fiber; stretching, heat-setting and cutting the second spun fiber to obtain the second fiber with heat shrinkage; The first fiber and the second fiber are mixed and then spun to obtain the cotton-feel composite polyester yarn.

2. The method for preparing a cotton-feel composite polyester yarn according to claim 1, wherein: In the step of preparing the first fiber, the polyethylene terephthalate raw material is spinning-grade polyethylene terephthalate chips, and the hygroscopic modifier is a hygroscopic polyester functional masterbatch; and in the step of preparing the second fiber, the polybutylene terephthalate raw material is spinning-grade polybutylene terephthalate chips.

3. The method for preparing a cotton-feel composite polyester yarn according to claim 1, wherein: The melt spinning in the step of preparing the first fiber includes: melt extrusion at a temperature of 240°C to 290°C, and spinning through a spinneret with special-shaped holes at a spinning temperature of 240°C to 290°C and a spinning speed of 1200m / min to 1500m / min; and the stretching includes: stretching in a stretching water tank at 60°C to 85°C, with a pre-stretching ratio of 1.05 to 1.10 and a main stretching ratio of 1.5 to 3.

5.

4. The method for preparing a cotton-feel composite polyester yarn according to claim 1, wherein: The melt spinning in the step of preparing the second fiber includes: melt extrusion at a temperature of 240°C to 280°C, and spinning through a porous spinneret at a spinning temperature of 230°C to 270°C and a spinning speed of 1200m / min to 1500m / min; and the stretching includes: in a stretching water tank at 60°C to 85°C, with a pre-stretching ratio of 1.05 to 1.10 and a main stretching ratio of 1.5 to 3.

5.

5. The method for preparing a cotton-feel composite polyester yarn according to claim 1, wherein: The special-shaped cross section of the first fiber is selected from a cross shape, a Y shape, or a four-leaf clover shape; and the moisture regain of the first fiber is in the range of 1.5% to 2.5%.

6. The method for preparing a cotton-feel composite polyester yarn according to claim 1, wherein: The first fibers have a fineness of 0.5D to 1.5D and a length of 38mm to 76mm; and the second fibers have a fineness of 0.5D to 1.5D and a length of 38mm to 76mm.

7. The method for preparing a cotton-feel composite polyester yarn according to claim 1, wherein: In the step of mixing the first fiber and the second fiber and then spinning the mixed fibers, the proportion of the first fiber is 65% to 75% by weight, and the proportion of the second fiber is 25% to 35% by weight.

8. The method for preparing a cotton-feel composite polyester yarn according to claim 1, wherein: The spinning step adopts a Siro compact spinning process.

9. The method for preparing a cotton-feel composite polyester yarn according to claim 1, wherein: The English count of the cotton-feel composite polyester yarn is 50S to 60S.

10. A method for preparing a cotton-feel polyester fabric, characterized in that: The steps include: Weaving a grey fabric using the cotton-feel composite polyester yarn prepared by the method for preparing the cotton-feel composite polyester yarn according to any one of claims 1 to 9 as a raw material; The grey cloth is subjected to dyeing and finishing treatment, wherein the dyeing and finishing treatment includes at least one heat treatment step, and the process parameters of the heat treatment step are sufficient to shrink the second fiber in the cotton-feel composite polyester yarn.

11. The method for preparing a cotton-feel polyester fabric according to claim 10, wherein: The weaving is knitting, and the formed grey fabric structure is a polyester-covered polyester-spandex plain weave structure, wherein the face yarn is made of the cotton-feel composite polyester yarn, and the base yarn is made of polybutylene terephthalate filament.

12. The method for preparing a cotton-feel polyester fabric according to claim 10, wherein: The dyeing and finishing treatment includes degreasing and shrinking, grey cloth setting, dyeing, reduction cleaning, finished product setting and drying processes in sequence; the degreasing and shrinking process is carried out at a temperature of 95°C to 105°C; the grey cloth setting process is carried out at a temperature of 180°C to 195°C; and the finished product setting process is carried out at a temperature of 145°C to 155°C.

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