Twist balance round soft cashmere-like blended core-spun yarn preparation method and fabric of twist balance round soft cashmere-like blended core-spun yarn

Abstract

The invention belongs to the technical field of spinning, and provides a twist balance round soft cashmere-like blended covering yarn as well as a preparation method and application of the twist balance round soft cashmere-like blended covering yarn. The twist balance round soft cashmere-like blended core-spun yarn is composed of core yarn and covering yarn, and the covering yarn is wound around the core yarn in a spiral shape. The core yarn is made of chemical fiber filaments, and the covering yarn is made of natural plant staple fibers; the twist of the core yarn is 80-720 T / m, and the twist of the covering yarn is 230-600 T / m; the twisting directions of the core yarn and the covering yarn are opposite. The chemical filaments and the natural plant short fibers which are opposite in twisting direction are adopted for core-spun yarn production, excessive twisting caused by a traditional two-for-one twisting process is effectively avoided, the stability and uniformity of the yarn are guaranteed, and woven fabric is light and soft and fine in hand feeling; and by optimizing the technological process, the production process is simplified, the productivity is improved, and the production cost is remarkably reduced.

Description

Technical Field

[0001] This invention belongs to the field of textile technology and relates to a method for preparing twist-balanced, round-soft, cashmere-like blended core-spun yarn and its fabric. Background Technology

[0002] As consumers increasingly demand comfort, quality, and value for money in clothing, traditional wool knitwear is gaining popularity due to its soft feel and excellent warmth. However, the high cost of wool materials, complex processing, and demanding care requirements, such as its susceptibility to pilling and shrinkage, limit its widespread application.

[0003] Blended yarns of synthetic filaments and natural plant staple fibers combine the high strength, abrasion resistance, and wrinkle resistance of synthetic filaments with the moisture absorption and breathability of natural plant staple fibers, making them widely used in clothing, home textiles, and other fields. However, the hand feel of blended yarns has always been a major concern in practical applications. Synthetic filaments, such as polyester, are hydrophobic fibers, offering a smooth feel but lacking the soft, skin-friendly feel of natural fibers. Furthermore, they are prone to static electricity during friction, causing the yarns to attract and entangle, affecting the hand feel. While natural plant staple fibers are soft and comfortable, their relatively low strength makes achieving a cashmere-like soft hand feel challenging.

[0004] Current methods for improving the hand feel of blended yarns have certain drawbacks. Conventional finishing processes, such as using softeners, can improve the hand feel to some extent, but the effect is not long-lasting, and the hand feel deteriorates significantly after multiple washes. Furthermore, some softeners may pose environmental concerns. Adjusting the blend ratio can change the hand feel, but it can affect the balance of other yarn properties. For example, increasing the proportion of cotton fibers to improve the hand feel may reduce yarn strength. Newer spinning methods, such as compact spinning, can improve fiber parallelism and cohesion, and improve yarn evenness, thus improving the hand feel, but the equipment costs are high. Twisting can give the yarn a certain degree of elasticity and softness, improving the hand feel, but excessive yarn twist can easily lead to defects such as small loops and thick spots being transferred to the fabric surface during weaving, affecting the fabric's smoothness and uniformity. Summary of the Invention

[0005] [Technical Issues]

[0006] Blended yarns of synthetic filaments and natural plant staple fibers are inexpensive but tend to be stiff and lack softness. Improving the hand feel through new processes like compact spinning is too costly. While appropriately twisting the yarn can improve its hand feel, it easily leads to unbalanced torsional stress, resulting in uneven yarn distribution, low weaving efficiency, and insufficient smoothness and uniformity in the fabric's appearance, resulting in a stiff hand feel. There is an urgent need for a low-cost, high-strength, comfortable, abrasion-resistant, shape-stable blended core-spun yarn that does not expose the core yarn, while retaining the advantages of both synthetic filaments and natural plant staple fibers and improving the appearance quality and dimensional stability of the resulting fabric.

[0007] [Technical Solution]

[0008] To address the aforementioned technical problems, this invention employs a twisted core yarn to enhance the strength of the core-spun yarn. By reverse twisting the core yarn with an outer covering yarn, the twist of the core yarn is balanced, significantly improving the quality and stability of the core-spun yarn production process. This also improves the hand feel of the core-spun yarn and its fabrics, solves the problems of exposed core yarn during core-spun yarn production and the formation of braided yarn due to self-twisting of the twisted core yarn, and overcomes the difficult problem of slanted sheets in single-yarn knitted fabrics.

[0009] The first objective of this invention is to provide a twist-balanced, round-soft, cashmere-like blended core-spun yarn, consisting of a core yarn and an outer wrapping yarn, with the outer wrapping yarn spirally wound around the core yarn. The core yarn is made of chemical fiber filaments, and the outer wrapping yarn is made of natural plant staple fibers. The core yarn twist is 80–720 T / m, and the outer wrapping yarn twist is 230–600 T / m. The twisting directions of the core yarn and the outer wrapping yarn are opposite. The chemical fiber filaments are selected from either polyester fiber filaments or polyamide fiber filaments.

[0010] In this context, the opposite twisting direction of the core yarn and the outer yarn means that when the core yarn is twisted in an S-twist direction, the outer yarn is twisted in a Z-twist direction; and when the core yarn is twisted in a Z-twist direction, the outer yarn is twisted in an S-twist direction.

[0011] In one embodiment of the present invention, the linear density of the core yarn is 10-150D, the linear density of the outer yarn is 10-85tex, and the linear density of the twist-balanced round soft imitation cashmere blended core-spun yarn is 16-100tex.

[0012] In one embodiment of the present invention, the chemical fiber filament is selected from one of polyester low elasticity yarn DTY, polybutylene terephthalate (PBT), and nylon.

[0013] In one embodiment of the present invention, the linear density of the chemical fiber filament is 10-150D and the crimp rate is 12-20%.

[0014] In one embodiment of the present invention, the natural plant short fiber is selected from one or more of cotton fiber, ramie fiber, flax fiber, bamboo fiber, and kapok fiber.

[0015] The second objective of this invention is to provide a method for preparing the above-mentioned twist-balanced, round-soft, cashmere-like blended core-spun yarn, comprising the following steps:

[0016] (1) Preparation of core yarn: Twist chemical fiber filaments to obtain twisted filaments;

[0017] (2) Preparation of core-spun yarn: Using twisted filament as core yarn, the stretched natural plant short fiber roving is twisted and wound around the core yarn to form an outer yarn, resulting in a twist-balanced, round, soft, cashmere-like blended core-spun yarn.

[0018] The twisting direction of the roving is opposite to that of the twisted filament.

[0019] The twisting direction of the outer yarn is opposite to that of the twisting direction of the twisted filament. This means that when the twisting direction of the twisted filament in step (1) is S-twist, the twisting direction of the outer yarn in step (2) is Z-twist; when the twisting direction of the twisted filament in step (1) is Z-twist, the twisting direction of the outer yarn in step (2) is S-twist.

[0020] In one embodiment of the present invention, in step (1), the twist is 310 to 950 T / m.

[0021] In one embodiment of the present invention, in step (2), the twist of the outer yarn is 230 to 600 T / m.

[0022] In the core-spun yarn process, twisted filaments are fed in through a feeding device, while natural plant short-fiber rovings cover the outer layer. Through twisting, the natural plant short fibers are evenly coated on the outside of the core yarn. Because the twisting direction of the core yarn is opposite to that of the outer fibers, the twist of the core yarn is reduced, and the reverse-twisted inner core yarn and outer roving create a balance of torsional stress. This not only ensures the overall structural stability of the core-spun yarn but also effectively improves the yarn's strength, softness, and resistance to deformation, thereby enhancing the yarn's quality and performance.

[0023] In one embodiment of the present invention, in step (2), the process parameters for preparing the core-spun yarn are: total draft ratio of 17 to 33; back zone draft ratio of 1.18 to 1.35; spindle speed of 6000 to 13000 r / min; center distance between the front and back rollers of 45 to 63 mm; and width of the spacer block of 3 to 4.5 mm.

[0024] Total draft ratio refers to the ratio of the length of the sliver after passing through the drafting device to its original length. It reflects the degree of stretching of the sliver by the drafting device.

[0025] The back zone drafting ratio refers to the ratio of the length of the sliver after stretching in the back zone drafting device to its length when entering the back zone. Back zone drafting prepares for front zone drafting and makes preliminary adjustments to the structure and state of the sliver.

[0026] In one embodiment of the present invention, in step (2), the equipment used to prepare the core-spun yarn has the functions of drafting, twisting and winding.

[0027] In one embodiment of the present invention, in step (2), core-spun yarn is prepared using a ring spinning machine or an air-jet spinning machine.

[0028] In one embodiment of the present invention, a brushing process is performed on the twist-balanced round soft imitation cashmere blended core-spun yarn to obtain a twist-balanced round soft imitation cashmere brushed core-spun yarn with a softer hand feel.

[0029] In the napping process, the yarn undergoes mechanical treatment to improve its surface softness and luster. During this process, the yarn is napped to create a uniform velvety effect, further producing a velvety feel.

[0030] In one embodiment of the present invention, the sanding process is carried out by using a grinding wheel, sandpaper, sanding roller or steel needle.

[0031] In one embodiment of the present invention, a double grinding wheel is used in the sanding process; the sanding machine speed is 35-45 m / min.

[0032] The third objective of this invention is to provide a twist-balanced, round-soft, cashmere-like brushed core-spun yarn prepared by the above-described preparation method.

[0033] A fourth objective of this invention is to provide the application of the above-mentioned twist-balanced round soft imitation cashmere blended core-spun yarn or twist-balanced round soft imitation cashmere brushed core-spun yarn in the textile field.

[0034] The fifth objective of this invention is to provide non-skew knitted fabrics made from the above-mentioned twist-balanced round soft imitation cashmere blended core-spun yarn or twist-balanced round soft imitation cashmere brushed core-spun yarn.

[0035] In one embodiment of the present invention, the knitted fabric includes single-yarn knitted fabric, double-yarn knitted fabric, and multi-ply knitted fabric.

[0036] The single-yarn knitted fabric is a fabric formed by a single yarn through a series of looping actions on a knitting machine.

[0037] Single-yarn knitted fabrics are more prone to skew, which is related to the twist and unevenness of the single yarn. The twist of the single yarn affects the degree of skew in the fabric. The fibers in a single yarn are arranged in a spiral shape, rotating around the yarn axis during twisting. If the twist is too low, the cohesion between fibers is weak, the yarn is prone to loosening, and fibers easily slip during weaving and use, leading to an unstable fabric structure and skewness. If the twist is too high, the yarn is too tight and stiff, making it difficult to form loops ideally during weaving, resulting in abnormal loop shapes and increasing the likelihood of fabric skewness. The uniformity of the single yarn affects the degree of skewness in single-yarn knitted fabrics. In actual production, the linear density and twist of the single yarn have a certain degree of unevenness. This unevenness causes differences in the mechanical properties of different sections of the single yarn. After being knitted, different areas shrink and deform at different degrees, generating internal stress. When this internal stress accumulates to a certain level, it leads to fabric skewness. The single-yarn knitted fabric made from the twist-balanced, round-soft, cashmere-like blended core-spun yarn of this invention has good uniformity and a smooth weave, avoiding the problem of slanted single-yarn knitted fabrics caused by yarn performance defects.

[0038] In a preferred embodiment of the present invention, in step (1), the chemical fiber filament is polyester low elastic DTY with a linear density of 75D and a crimp rate of 13%, and the twist is 340T / m with an S-twist direction; in step (2), the outer yarn has a twist of 460T / m with a Z-twist direction, the outer yarn has a linear density of 33.4tex, and the linear density of the prepared twist-balanced round soft imitation cashmere polyester cotton core-spun yarn is 41.7tex.

[0039] In a preferred embodiment of the present invention, in step (1), the chemical fiber filament is polyester low elastic DTY with a linear density of 75D and a crimp rate of 19%, the twist is 380T / m, and the twist direction is S twist; in step (2), the twist of the outer yarn is 550T / m, the twist direction is Z twist, the linear density of the outer yarn is 25tex, and the linear density of the resulting twist-balanced round soft imitation cashmere polyester cotton core-spun yarn is 33.3tex.

[0040] In a preferred embodiment of the present invention, in step (1), the chemical fiber filament is polyester low elastic DTY with a linear density of 150D and a crimp rate of 19%, the twist is 600T / m, and the twist direction is S twist; in step (2), the twist of the outer yarn is 260T / m, the twist direction is Z twist, the linear density of the outer yarn is 83.3tex, and the linear density of the prepared twist-balanced round soft imitation cashmere polyester cotton core-spun yarn is 100tex.

[0041] In a preferred embodiment of the present invention, in step (1), the chemical fiber filament is polyester low elastic DTY with a linear density of 150D and a crimp rate of 19%, the twist is 500T / m, and the twist direction is S twist; in step (2), the outer yarn has a twist of 300T / m and a twist direction of Z twist, the outer yarn has a linear density of 54.7tex, and the linear density of the prepared twist-balanced round soft imitation cashmere polyester cotton core-spun yarn is 71.4tex.

[0042] The core-spun yarn preparation method provided by this invention has extremely high inclusiveness in the selection of raw materials. Commercially available natural plant staple fiber rovings can all be well applied in this method.

[0043] In one embodiment of the present invention, the twist of the roving is 24-85 T / m; the linear density of the roving is 200-1000 tex.

[0044] The following is a method for preparing natural plant short fiber roving:

[0045] Natural plant short fibers are processed into roving through opening, carding, drawing, and roving processes.

[0046] The cotton opening and cleaning process follows the principles of taking multiple bales, carefully handling the cotton, gradually opening and loosening it, removing small pieces early and reducing breakage, using combing instead of beating, and minimizing fiber damage.

[0047] After opening and cleaning, natural plant short fibers are fed into the carding equipment via a feed plate and feed rollers, transferring the fibers to the licker-in. The fibers are then separated by the carding cloth on the cylinder adjacent to the licker-in. The fibers undergo free opening and processing between the cylinder and the rear rotating flats, free transfer and carding between the cylinder and the middle rotating flats, and finally carding between the cylinder and the front rotating flats. Next, the fibers are stripped by the carding cloth on the doffer, forming a fiber web, which is then gathered into a fiber sliver through a bell mouth. After pressing and processing, a sliver is obtained, which is then wound into cans by a winding system. In the carding process, the sliver weight is 180–300 g / 5m; the cylinder speed is 300–420 r / min; and the licker-in speed is 700–1500 r / min.

[0048] The drawing process involves drawing the raw sliver obtained after carding through two drawing processes to produce a finished sliver. In the drawing process, the raw sliver is repeatedly drawn together to ensure that the weight unevenness of the fiber sliver is no higher than 1.5%, thereby significantly improving the straightness and parallelism of the fibers.

[0049] In the roving process, the sliver is tensioned by the rollers in the back drafting zone and then stretched by the aprons in the front drafting zone. The fiber sliver is then twisted by the spindle wings to form roving. In the roving process, the total draft ratio is 5–10; the back draft ratio is 1.1–1.3; the twist coefficient is 60–130; the dry weight is 2–10 g / 10m; and the spindle speed is 800–1200 r / min.

[0050] Beneficial effects:

[0051] The polyester-cotton knitwear produced by this invention has a very soft touch and a high-end appearance, closely resembling the delicate feel of natural cashmere. Due to the use of a blend of polyester and cotton fibers, the finished fabric is not only comfortable and skin-friendly but also possesses a certain degree of breathability and warmth, suitable for various seasons. Its smooth and delicate surface, soft color, and overall aesthetically pleasing and sophisticated appearance perfectly meet the market demand for high-quality, comfortable, and luxurious knitwear.

[0052] In terms of technology, this invention employs a core-spun process using polyester low-elasticity yarn with opposite twist directions and natural plant short fibers. The natural plant short fibers are combined with the filaments through core-spun technology on a spinning machine to produce a cashmere-like single yarn. This process effectively avoids the excessive twisting caused by traditional double-twisting processes, while ensuring the stability and uniformity of the yarn. This results in a fabric that is lightweight yet has a softer and more delicate feel. The process also optimizes the yarn structure, giving it both the strength of polyester and the softness of cotton, while also providing good wrinkle resistance and durability.

[0053] The core-spun yarn of this invention maintains low torque during weaving, reducing yarn stretching and deformation, thereby avoiding unevenness or irregular weave in the fabric. Furthermore, compared to commercially available core-spun yarns, the core-spun yarn of this invention produces a finer weave, making it suitable for the production of high-quality fabrics. It achieves a smoother, more refined fabric surface, enhancing the overall comfort and aesthetics of the fabric.

[0054] By reverse twisting the core yarn and outer yarn, a twist-balanced, round-spun, cashmere-like blended core-spun yarn and knitwear are produced, resulting in a soft and delicate hand feel with a cashmere-like effect. The resulting knitwear combines the natural comfort of natural plant short fibers with the softness and delicacy of cashmere, offering lightweight, breathability, and comfort. Compared to traditional cashmere, improvements in the spinning process not only achieve a cashmere-like feel but also significantly enhance softness and delicacy, while retaining the excellent moisture absorption and breathability of natural plant short fibers, making it suitable for everyday wear and providing a more comfortable wearing experience.

[0055] By optimizing the process flow and eliminating the doubling step, the overall production process has been simplified, significantly improving production efficiency. For example, the output of 41.7tex core-spun yarn can reach 386 kg / unit, doubling the output compared to the traditional process for producing 20.8tex / 2 yarn. In terms of cost, the traditional doubling process is expensive (e.g., 48NM / 2 doubling costs 2800 yuan / ton), while after optimization, the filament content of 41.7tex core-spun yarn is only 20%, and the increased cost per ton is only 1000 yuan, resulting in a significant reduction in overall cost per ton of yarn. This process optimization not only increases production capacity but also significantly reduces production costs, greatly enhancing the company's market competitiveness. Attached Figure Description

[0056] Figure 1 This is a process flow diagram for Example 1.

[0057] Figure 2 The fabric pieces are knitted sweaters made from polyester-cotton yarn in Example 5 and Comparative Example 1.

[0058] Figure 3 Cross-sectional slices of the twist-balanced round soft imitation cashmere polyester-cotton core-spun yarn prepared in Examples 5 and 6 and the polyester-cotton yarns in Comparative Examples 1 and 2.

[0059] Figure 4 The longitudinal morphology of the twist-balanced round soft imitation cashmere pure cotton core-spun yarn prepared in Examples 5 and 6 and the polyester-cotton yarn in Comparative Examples 1 and 2 are shown. Detailed Implementation

[0060] Example 1

[0061] The production process of blended knitwear includes the following steps:

[0062] S1. Preparation of roving: Natural plant short fiber loose fibers are prepared into roving through dyeing, wool mixing, carding, drawing, and roving processes; the sliver weight in the carding process is 180-250 g / 5m; the cylinder speed is 330-380 r / min; the licker-in speed is 700-1200 r / min; the weight unevenness of the drawing is not higher than 1.5%; in the roving process, the total draft ratio is 6.3-6.9, the back zone draft ratio is 1.2-1.3, the twist coefficient is 60-130, the dry weight is 5-7 g / 10m, and the spindle speed is 850-1000 r / min;

[0063] S2. Preparation of core yarn: Use polyester low elastic DTY or PBT with a linear density of 75-150D to add S twist on a filament doubling machine to obtain twisted filament; the twist degree is 310-950T / M.

[0064] S3. Preparation of core-spun yarn: Using twisted filament as core yarn and roving as outer yarn, the outer yarn is twisted to cover the core yarn, and the outer yarn is Z-twisted to obtain twist-balanced, round, soft, cashmere-like polyester-cotton core-spun yarn; the twist is 230-600 T / m; the total draft ratio is 17-33; the back zone draft ratio is 1.18-1.35; the spindle speed is 8000-13000 r / min; the center distance between the front and back rollers is 45-63 mm, and the width of the spacer block is 3-4.5 mm.

[0065] S4. Twist-balanced round soft imitation cashmere polyester-cotton core-spun yarn is woven into a single yarn knitted sweater; the knitting machine is 12-gauge and the fabric structure is plain weave.

[0066] Example 2

[0067] The production process of blended knitwear includes the following steps:

[0068] S1. Preparation of roving: High-quality cotton fibers are processed through opening and cleaning, carding, drawing, and roving processes to prepare roving; the sliver weight in the carding process is 220g / 5m; the cylinder speed is 360r / min; the licker-in speed is 1100r / min; the drawing process is completed until the weight unevenness is reduced to 1.2%; in the roving process, the total draft ratio is 6.3, the back zone draft ratio is 1.2, the twist coefficient is 130, the dry weight is 7g / 10m, and the spindle speed is 1000r / min;

[0069] S2. Preparation of core yarn: Use 75D low-elastic polyester DTY to add S twist on a filament doubling machine to obtain twisted filament; the twist degree is 340T / M;

[0070] S3. Preparation of core-spun yarn: Using twisted filament as core yarn and natural plant short fiber roving as outer yarn, the outer yarn is twisted to cover the core yarn, and the outer yarn is Z-twisted to obtain twist-balanced, round, soft, cashmere-like polyester-cotton core-spun yarn; the twist is 460T / m; the total draft ratio is 22-23.5; the back zone draft ratio is 1.2; the spindle speed is 10000r / min; the center distance between the front and back rollers is 45mm and 60mm respectively, and the width of the spacer block is 3.5mm;

[0071] After the outer yarn is wrapped by reverse twisting in step S3, the residual twist of the twisted filament (i.e. the core yarn twist of the core-spun yarn) is 120T / m, the core yarn linear density is 75D, the outer yarn twist is 460T / m, the outer yarn linear density is 33.4tex, and the linear density of the resulting twist-balanced round soft imitation cashmere polyester-cotton core-spun yarn is 41.7tex.

[0072] S4. Twist-balanced round soft imitation cashmere polyester-cotton core-spun yarn is woven into a single yarn knitted sweater; the knitting machine is 12-gauge and the fabric structure is plain weave.

[0073] Example 3

[0074] The production process of blended knitwear includes the following steps:

[0075] S1. Preparation of roving: High-quality cotton fibers are processed through opening and cleaning, carding, drawing, and roving processes to prepare roving; the sliver weight in the carding process is 220g / 5m; the cylinder speed is 360r / min; the licker-in speed is 1100r / min; the drawing process is completed until the weight unevenness is reduced to 1.2%; in the roving process, the total draft ratio is 6.3, the back zone draft ratio is 1.2, the twist coefficient is 130, the dry weight is 7g / 10m, and the spindle speed is 1000r / min;

[0076] S2. Preparation of core yarn: Use 75D low-elastic polyester DTY to add S twist on a filament doubling machine to obtain twisted filament; the twist degree is 380T / M;

[0077] S3. Preparation of core-spun yarn: Using twisted filament as core yarn and natural plant short fiber roving as outer yarn, the outer yarn is twisted to cover the core yarn, and the outer yarn is Z-twisted to obtain twist-balanced, round, soft, cashmere-like polyester-cotton core-spun yarn; the twist is 550T / m; the total draft ratio is 29.4~30.8; the back zone draft ratio is 1.2; the spindle speed is 12000r / min; the center distance between the front and back rollers is 45 and 60mm respectively, and the width of the spacer block is 3mm;

[0078] After the outer yarn is wrapped by reverse twisting in step S3, the residual twist of the twisted filament (i.e. the core yarn twist of the core-spun yarn) is 170T / m, the core yarn linear density is 75D, the outer yarn twist is 550T / m, the outer yarn linear density is 25tex, and the linear density of the resulting twist-balanced round soft imitation cashmere polyester-cotton core-spun yarn is 33.3tex.

[0079] S4. Twist-balanced round soft imitation cashmere polyester-cotton core-spun yarn is woven into a single yarn knitted sweater; the knitting machine is 12-gauge and the fabric structure is plain weave.

[0080] Example 4

[0081] The production process of blended knitwear includes the following steps:

[0082] S1. Preparation of roving: High-quality cotton fibers are processed through opening and cleaning, carding, drawing, and roving processes to prepare roving; the sliver weight in the carding process is 220g / 5m; the cylinder speed is 360r / min; the licker-in speed is 1100r / min; the drawing process is completed until the weight unevenness is reduced to 1.2%; in the roving process, the total draft ratio is 6.3, the back zone draft ratio is 1.2, the twist coefficient is 108, the dry weight is 7g / 10m, and the spindle speed is 1000r / min;

[0083] S2. Preparation of core yarn: Polyester low-elasticity DTY with a linear density of 150D is twisted by S-twist on a filament doubling machine to obtain twisted filament; the twist degree is 600T / M;

[0084] S3. Preparation of core-spun yarn: Using twisted filament as core yarn and natural plant short fiber roving as outer yarn, the outer yarn is twisted to cover the core yarn, and the outer yarn is Z-twisted to obtain twist-balanced, round, soft, cashmere-like polyester-cotton core-spun yarn; the twist is 260T / m; the total draft ratio is 17.8-18.5; the back zone draft ratio is 1.2; the spindle speed is 6000r / min; the center distance between the front and back rollers is 45mm and 60mm respectively, and the width of the spacer block is 3.5mm;

[0085] After the outer yarn is wrapped by reverse twisting in step S3, the residual twist of the twisted filament (i.e. the core yarn twist of the core-spun yarn) is 340T / m, the core yarn linear density is 150D, the outer yarn twist is 260T / m, the outer yarn linear density is 83.3tex, and the linear density of the resulting twist-balanced round soft imitation cashmere polyester-cotton core-spun yarn is 100tex.

[0086] S4. Twist-balanced round soft imitation cashmere polyester-cotton core-spun yarn is woven into a single yarn knitted sweater; the knitting machine is 9-gauge and the fabric structure is plain weave.

[0087] Example 5

[0088] The production process of blended knitwear includes the following steps:

[0089] S1. Preparation of roving: High-quality cotton fibers are processed through opening and cleaning, carding, drawing, and roving processes to prepare roving; the sliver weight in the carding process is 220g / 5m; the cylinder speed is 360r / min; the licker-in speed is 1100r / min; the drawing process is completed until the weight unevenness is reduced to 1.2%; in the roving process, the total draft ratio is 6.3, the back zone draft ratio is 1.2, the twist coefficient is 108, the dry weight is 7g / 10m, and the spindle speed is 1000r / min;

[0090] S2. Preparation of core yarn: Polyester low-elasticity DTY with a linear density of 150D is twisted by S-twist on a filament doubling machine to obtain twisted filament; the twist degree is 500T / M.

[0091] S3. Preparation of core-spun yarn: Using twisted filament as core yarn and natural plant short fiber roving as outer yarn, the outer yarn is twisted to cover the core yarn, and the outer yarn is Z-twisted to obtain twist-balanced, round, soft, cashmere-like polyester-cotton core-spun yarn; the twist is 300T / m; the total draft ratio is 27.5-28.5; the back zone draft ratio is 1.2; the spindle speed is 6000r / min; the center distance between the front and back rollers is 45mm and 60mm respectively, and the width of the spacer block is 3.5mm;

[0092] After the outer yarn is wrapped by reverse twisting in step S3, the residual twist of the twisted filament (i.e. the core yarn twist of the core-spun yarn) is 200T / m, the core yarn linear density is 150D, the outer yarn twist is 300T / m, the outer yarn linear density is 54.7tex, and the linear density of the resulting twist-balanced round soft imitation cashmere polyester-cotton core-spun yarn is 71.4tex.

[0093] S4. The core-spun yarn is brushed with double grinding wheels to obtain a twist-balanced, round, soft, cashmere-like brushed core-spun yarn; the brushing machine speed is 35-45 m / min.

[0094] S5. Twist-balanced round soft imitation cashmere brushed core-spun yarn is woven into a single yarn knitted sweater; the knitting machine size is 12 needles, and the fabric structure is plain weave.

[0095] Example 6

[0096] The difference from Example 5 is that step S4 is not performed.

[0097] Comparative Example 1

[0098] 71.4tex ordinary twist polyester-cotton yarn, with a twist of 350T / m.

[0099] Comparative Example 2

[0100] 71.4tex low-twist polyester-cotton yarn, with a twist of 300T / m.

[0101] Comparative Example 3

[0102] The difference from Example 5 is that both the core yarn and the outer yarn are S-twist.

[0103] Figure 2 These are fabric sheets of knitted sweaters made from Example 5 (patented yarn) and Comparative Example 1 (polyester-cotton yarn with normal twist). The twist-balanced, soft, cashmere-like polyester-cotton core-spun yarn has balanced torque, resulting in a fabric without skew. In contrast, the conventional polyester-cotton yarn of Comparative Example 1 has high torque, leading to severe skew. The core-spun yarn of Comparative Example 3 has unbalanced torque, resulting in severe skew.

[0104] Figure 3 The figures show cross-sectional slices of the twist-balanced, round, soft, cashmere-like polyester-cotton core-spun yarns prepared in Examples 5 and 6, and the polyester-cotton yarns in Comparative Examples 1 and 2. The white parts in the figures represent the yarn cross-sections. The core-spun yarn (patented yarn) prepared in Example 5 and the core-spun yarn (patented yarn before brushing) prepared in Example 6 have balanced torque, stable yarn structure, and circular cross-sections. The polyester-cotton yarns (ordinary twist yarn and low twist yarn) in Comparative Examples 1 and 2 have high torque and flattened yarn cross-sections.

[0105] Figure 4 The figures show the longitudinal morphology of the core-spun yarns (patented yarn, patented yarn before brushing) prepared in Examples 5 and 6, and the polyester-cotton yarns (ordinary twist yarn, low twist yarn) in Comparative Examples 1 and 2. The core-spun yarns in Examples 5 and 6 have more short cotton fibers around their edges than the other comparative examples, resulting in a fluffy effect, which indirectly confirms the good hand feel of this patented yarn. The core-spun yarn prepared in Comparative Example 3 has less short cotton fibers around its edges than that in Examples 3 and 4.

[0106] The amount of short cotton fibers around the core-spun yarn is related to the twist and twisting direction of the core yarn and the outer covering yarn. When the twist of the core yarn or the outer covering yarn is low, the cohesion between fibers is weak, which easily leads to insufficient coverage of the core yarn by the outer covering yarn, reducing the effective content of short fibers on the surface of the core-spun yarn. If the twist of the core yarn or the outer covering yarn is too high, when the core yarn and the outer covering yarn are combined, some short fibers are easily broken or squeezed into the yarn due to excessive rigidity, which is not conducive to increasing the amount of short fibers on the yarn surface.

[0107] Example 7

[0108] The production process of the blended knitwear differs from that of Example 2 in that, in step S1, high-quality cotton fiber is replaced with flax fiber, and in step S2, polyester is replaced with PBT.

[0109] Example 8

[0110] The production process of the blended knitwear differs from that of Example 2 in that, in step S1, high-quality cotton fiber is replaced with kapok fiber and cotton fiber, and the mass ratio of kapok fiber and cotton fiber is 1:5; and in step S2, polyester is replaced with nylon.

[0111] Example 9

[0112] The production process of the blended knitwear differs from that of Example 2 in that S twist is replaced with Z twist in step S2, and Z twist is replaced with S twist in step S3.

[0113] The breaking strength of the twist-balanced, round-spun, cashmere-like polyester-cotton core-spun yarn prepared in Example 9 is similar to that of the twist-balanced, round-spun, cashmere-like polyester-cotton core-spun yarn prepared in Example 5. The blended knitwear prepared in Example 9 is similar to that prepared in Example 5, without any skewing issue. This indicates that the twisting direction of the filament in step S2 is opposite to the twisting direction of the covering yarn in step S3, thus avoiding skewing caused by yarn defects.

[0114] Example 10

[0115] The production process of blended knitwear differs from that of Example 2 in that the ring spinning machine is replaced with an air-jet spinning machine in step S3.

[0116] The breaking strength of the twist-balanced, round-spun, cashmere-like polyester-cotton core-spun yarn prepared in Example 10 is similar to that of the twist-balanced, round-spun, cashmere-like polyester-cotton core-spun yarn prepared in Example 5. The blended knitwear prepared in Example 10 is similar to that prepared in Example 5, without the problem of yarn skew. Using an air-jet spinning machine to prepare core-spun yarn can also achieve the technical effect of avoiding yarn skew in this invention.

[0117] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A twist balanced circular soft cashmere blend core spun yarn characterized in that, It is composed of core yarn and outer wrapping yarn, the outer wrapping yarn is spirally wound around the core yarn; the core yarn is made of chemical fiber filament, the outer wrapping yarn is made of natural plant short fiber; the twist of the core yarn is 80-720T / m, the twist of the outer wrapping yarn is 230-600T / m; the twist directions of the core yarn and the outer wrapping yarn are opposite; the chemical fiber filament is selected from one of polyester fiber filament and polyamide fiber filament.

2. The twist balanced circular soft cashmere blended core spun yarn as claimed in claim 1, wherein, The linear density of the core yarn is 10-150D, the linear density of the outer wrapping yarn is 10-85tex; the linear density of the twist balance round soft cashmere blended core yarn is 16-100tex; the chemical fiber filament is selected from one of polyester DTY, PBT and nylon; the natural plant short fiber is selected from one or more of cotton fiber, ramie fiber, flax fiber, bamboo fiber and kapok fiber.

3. A process for the production of twist balanced circular soft cashmere blend core spun yarn as claimed in claim 1, wherein, It comprises the following steps: (1) preparing core yarn: twisting the chemical fiber filament to obtain twisted filament; (2) preparing core yarn: twisting and winding the drafted natural plant short fiber roving sliver around the core yarn to form outer wrapping yarn to obtain twist balance round soft cashmere blended core yarn; The twisting direction of the roving is opposite to that of the twisted filament.

4. The production method according to claim 3, characterized by, In step (1), the twist of the twisted filament is 310-950T / m; the linear density of the twisted filament is 10-150D.

5. The preparation method according to claim 3, characterized in that, In step (2), the twist of the outer wrapping yarn is 230-600T / m; the linear density of the outer wrapping yarn is 10-85tex; The equipment for preparing the core yarn has the functions of drafting, twisting and winding; The process parameters for preparing the core yarn are as follows: total drafting multiple is 17-33; back zone drafting multiple is 1.18-1.35; spindle speed is 6000-13000r / min; the center distance of front and back rollers is 45-63mm respectively, and the width of the spacer block is 3-4.5mm.

6. The preparation method according to claim 3, characterized in that, The twist balance round soft cashmere blended core yarn is subjected to the sanding process to obtain twist balance round soft cashmere sanding core yarn.

7. The twist balance round soft cashmere sanding core yarn prepared according to claim 6.

8. The application of the twist balance round soft cashmere blended core yarn according to claim 1 or 2 or the twist balance round soft cashmere sanding core yarn according to claim 7 in the field of textiles.

9. The non-inclined piece knitted fabric made of the twist balance round soft cashmere blended core yarn according to claim 1 or 2 or the twist balance round soft cashmere sanding core yarn according to claim 7.

10. The biasing knitted fabric of claim 9, wherein, It includes single yarn knitted fabric, double yarn knitted fabric and multi-strand yarn knitted fabric.

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