A composite structure bulked yarn and a production process thereof

Abstract

The application provides a composite structure bulk yarn and a production process thereof, and belongs to the technical field of textiles. The production process comprises the following steps: feeding a high-shrinkage acrylic core yarn roving, a low-shrinkage intermediate layer roving, and a combined twist yarn (dry heat setting) of water-soluble vinylon filaments and superfine polyester filaments into a spinning frame for spinning to obtain a composite structure yarn; and then treating the composite structure yarn in hot water to dissolve the water-soluble vinylon filaments, heat-shrink the high-shrinkage acrylic fibers, and release the twist of the superfine polyester filaments, so that the superfine polyester filaments are wound on the surface of the yarn in a spiral bending state and form a kink structure in some segments, thereby obtaining the composite structure bulk yarn. The bulk yarn is composed of a core yarn, an intermediate layer yarn and an outer filament, has a unique spiral bending and kink appearance, and has excellent bulk properties, smooth hand feeling, surface wear resistance and structural stability, and can be widely applied to the fields of weaving and knitting.

Description

Technical Field

[0001] This invention relates to the field of textile technology, specifically to a composite structure bulky yarn and its production process. Background Technology

[0002] Bulk yarn is made by blending high-shrinkage fibers with conventional low-shrinkage fibers in a specific ratio, followed by a wet heat setting treatment to create a core-sheath structure with a loose outer layer. The principle is that high-shrinkage fibers shrink significantly during heat treatment, concentrating in the yarn core; low-shrinkage fibers, due to their smaller shrinkage, are compressed and coiled, forming a fluffy outer layer. The yarn diameter can often be increased by more than double, significantly increasing internal air storage capacity. Traditional bulk yarn mainly uses acrylic fibers (a blend of high-shrinkage acrylic and ordinary acrylic), but blends such as wool-acrylic, rabbit-acrylic, and polyester-acrylic are also available. It typically uses yarns with a specification of 100 tex or higher, spun using wool spinning technology, which limits the manufacturing process. Bulk yarn has advantages such as fluffiness, warmth, softness, and good elasticity, but it also has disadvantages such as poor abrasion resistance, easy shedding, and low shape retention. Therefore, it is mainly limited to applications such as hats and scarves that are not frequently washed and experience less friction.

[0003] In the prior art, patent document CN102268759A discloses a method for preparing bulky yarn. This method involves spinning colored shrinkable acrylic short fibers alone or blending them with other fibers, followed by bulking treatment using electrically heated dry air, thus changing the traditional method of bulking in high-temperature water. However, the bulky yarn obtained by this method still has a traditional blended structure, lacking identifiable appearance features on the yarn surface, and the bulking effect achieved solely through fiber blending is limited, failing to balance bulkiness and surface abrasion resistance. Patent document CN106087217A discloses a method for producing a heat-retaining and heat-generating bulky double-layer structure yarn for warm knitted fabric. This method blends four short fibers—heat-retaining and heat-generating fibers, regenerated cellulose fibers, water-soluble vinylon, and high-shrinkage acrylic fibers—into yarn, then dissolves the water-soluble vinylon through hot water treatment. Simultaneously, the high-shrinkage acrylic fibers undergo thermal shrinkage, producing a bulking effect, resulting in a double-layer hollow structure yarn. This method utilizes the dissolution of water-soluble vinylon to create internal voids in the yarn and uses the shrinkage of the high-shrinkage acrylic fibers to cause the other fibers to curl. However, this method uses a blend of four short fibers, resulting in random fiber distribution within the yarn cross-section, making precise control of the layered structure impossible. Furthermore, the water-soluble vinylon, incorporated as short fibers, creates unevenly sized and distributed voids after dissolution, leading to a loose yarn structure and limited mechanical properties. Patent document CN108060484A discloses a core-spun yarn and its preparation method, using water-soluble vinylon fiber bundles as the core material and the main fiber component as the outer layer. After dissolving the water-soluble vinylon in the core, a hollow yarn is obtained. This method employs a core-sheath structure, with the core material being water-soluble fiber. Dissolution only yields hollow channels, but the outer main fiber layer lacks a bulking effect, and the yarn as a whole retains the shape of a tightly packed yarn with extremely limited loft.

[0004] In addition, the aforementioned existing technologies share a common technical problem: while creating gaps by dissolving water-soluble fibers, the morphological changes of the filaments or fiber layers wrapped around the yarn surface are not effectively utilized, resulting in a relatively monotonous appearance of the yarn surface.

[0005] Based on this, this application aims to propose a bulky yarn that, while achieving excellent bulking effect, also takes into account the abrasion resistance and silky feel of the yarn surface, and at the same time has a more unique appearance. Summary of the Invention

[0006] This invention addresses the aforementioned problems in the prior art by providing a composite structure bulky yarn and its production process. Through a three-layer structure design consisting of a core layer of high-shrinkage fiber, a middle layer of soft short fiber, and an outer layer of heat-set polyester filament, and by controlling the accompanying spinning-dissolving process of water-soluble vinylon filament, a bulky yarn with excellent bulking properties, silky feel, surface abrasion resistance, and unique appearance is obtained, thus broadening the product application range of bulky yarn.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: In a first aspect, the present invention provides a production process for composite structure bulky yarn, characterized by comprising the following steps: S1, preparing composite structure yarn. The core roving, intermediate roving, and outer twisted yarn are simultaneously fed into a spinning machine to obtain a composite structure yarn. The core roving is fed from the back roller, the intermediate roving is fed from both sides of the core roving from the middle roller, and the outer twisted yarn is fed between the front roller and the middle roller, maintaining a certain distance from the intermediate roving sliver during feeding. The core roving is made from high-shrinkage acrylic fibers through a roving process, and the intermediate roving is made from low-shrinkage fibers through a roving process. The shrinkage rate of the low-shrinkage fibers is lower than that of the high-shrinkage acrylic fibers. The low-shrinkage fibers include first core yarn fibers and second core yarn short fibers. The outer twisted yarn is a combined twisted yarn of water-soluble vinylon filament and ultrafine polyester filament, with a twist coefficient of 400~460, and is subjected to dry heat setting treatment to obtain a twisted yarn with stable twist. S2, Prepare composite structure bulky yarn. The composite structure yarn obtained in step S1 is treated in hot water at a temperature lower than the dry heat setting temperature. This causes the water-soluble vinylon filament to dissolve and the high-shrinkage acrylic fiber to undergo thermal shrinkage. After the water-soluble vinylon filament dissolves, the ultrafine polyester filament releases its twist and is wound around the yarn surface in a spiral bending state, with some sections forming a twisted structure, thus obtaining the composite structure bulky yarn.

[0008] Furthermore, the first core yarn fiber is modal fiber, and the second core yarn short fiber is a mixture of cashmere and silk short fibers.

[0009] Furthermore, the dry heat setting temperature is 120~140℃.

[0010] Furthermore, the hot water temperature in step S2 is 80~100℃, which is higher than the water solubility temperature of water-soluble vinylon filament.

[0011] Furthermore, the linear density ratio of the water-soluble vinylon filament to the ultrafine polyester filament is 1:2~4.

[0012] Furthermore, in step S2, the composite structure yarn is subjected to hot water treatment in the form of skein yarn.

[0013] On the other hand, the present invention provides a composite structure bulky yarn, characterized in that it is produced by the above-mentioned production process and includes... The core yarn (A) is composed of high-shrinkage fibers; the intermediate layer yarn, which covers the outer periphery of the core yarn, is composed of low-shrinkage fibers. The outer filament, which covers the outer periphery of the middle layer yarn, is composed of ultrafine polyester filament; the ultrafine polyester filament is wound around the yarn surface in a spiral bending state, and some sections form a twisted structure. The core yarn shrinks and concentrates at the center of the yarn after heat shrinkage, forcing the middle layer yarn and the outer layer filament to bulge outward to form a bulky structure.

[0014] Furthermore, the high-shrinkage fiber is a high-shrinkage acrylic fiber with a specification of 1.5~2.4 dtex and a fiber length of 65~80 mm.

[0015] Furthermore, the intermediate layer yarn comprises at least two rovings, each made of a different fiber material. Preferably, the intermediate layer yarn comprises a first roving (B1) made of modal fiber and a second roving (B2) made of a blend of cashmere and silk.

[0016] Compared with the prior art, the present invention has the following advantages: (1) Unique yarn appearance: Through the process of water-soluble vinylon filament spinning → twisting and heat setting → melting and untwisting, the ultrafine polyester filament presents a unique spiral bending and twisting ("braids") effect on the yarn surface, which has a very high visual recognition. This uniform and smooth spiral bending and twisting appearance can only be stably obtained under the process design where the heat setting temperature is significantly higher than the finishing temperature. At the same time, the efficient axial shrinkage of the core yarn allows the surface filaments to fully bulge and twist, avoiding the problem of local arching or incomplete twisting of the yarn.

[0017] (2) Excellent comprehensive performance: The yarn has multiple performance advantages, including fluffy warmth (the three-layer structure forms a large number of still air layers), silky smooth surface (covered by ultra-fine polyester filaments), good abrasion resistance (the filaments provide protection), and soft hand feel (the middle layer uses ultra-soft fibers such as modal and cashmere). Compared with traditional bulky yarn, the abrasion resistance is greatly improved; compared with water-soluble fiber hollow yarn, the fluffiness and fullness are significantly improved.

[0018] (3) Stable and controllable structure: The fiber stacking and swelling are achieved by shrinking the core yarn along its length. The core yarn uses wool-type long fibers to prevent fiber slippage. The structure of the middle layer fiber and the outer layer filament is clear and controllable, avoiding the problem of random and uncontrollable fiber distribution in traditional blending methods. The outer layer twisted yarn is heat-set before spinning, and the spiral shape of the polyester filament is stably locked and will not loosen or disappear during use and washing.

[0019] (4) Wide range of applications: Compared with traditional bulky yarn and belly yarn, which mostly use yarns of 100 tex or more, and have a looser structure, and are produced using wool spinning technology, this invention has finer yarns with a smoother surface and a more stable structure. It is produced using cotton spinning technology and can be widely used in weaving, knitting and other fields. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the composite structure bulky yarn of the present invention; In the diagram: A - core yarn, B1 - first roving, B2 - second roving, C - outer filament, D - knot. Detailed Implementation

[0021] The principles and features of the present invention are described below. The embodiments given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0022] Example 1 (a) Raw material selection: High-shrinkage acrylic fiber: Specifications 1.67dtex×76mm, heat shrinkage rate (boiling water) 18%; Modal fiber: Specifications 1.22dtex × 38mm; Cashmere: Diameter 16~19μm, cut length 40mm; Silk: Cut length 40mm; Water-soluble vinylon filament: 30D / 10f, water-soluble temperature 60~70℃; Ultrafine polyester filament: 72D / 144f, heat setting temperature 80~100℃.

[0023] (II) Preparation of core yarn A: High-shrinkage acrylic fiber is produced into roving using FB412, FB423, FB432, FB4442, and FB465 roving frames. Details are as follows: The following are types of combing machines: FB412 (6 combed yarns, 24.5g / 5mm weight, 10 needles / inch × 193mm × 99 yarns); FB423 (4 combed yarns, 22.2g / 5mm weight, 10 needles / inch × 193mm × 99 yarns); FB432 (3 combed yarns, 18.1g / 5mm weight, 13 needles / inch × 193mm × 144 yarns); FB4442 (2 combed yarns, 14.3g / 5mm weight, 13 needles / inch × 193mm × 144 yarns); FB465 (6.2g / 10mm weight, 2.1 twist / 10cm, front × back roller spacing: 56 × 110mm).

[0024] (III) Preparation of intermediate layer yarn: B1 Yarn (Modal): Modal fiber, produced into roving using a carding and cleaning unit, a JWF1310 drawing frame, a JWF1310 drawing frame, and a JWF1456 roving frame. Details are as follows: The weight of the carding and combing unit is 22.5g / 5m; the weight of the first drawing sliver is 22.9g / 5m and the speed is 350m / min; the weight of the second drawing sliver is 18.7g / 5m and the speed is 350m / min; the weight of the JWF1456 roving frame is 4.9g / 10m and the spindle speed is 950r / min.

[0025] B2 yarn (cashmere / silk 50 / 50): Cashmere and silk are cut, weighed, and mixed. An oil-water mixture and antistatic agent are sprayed on, and the mixture is covered with plastic film for 24 hours. The yarn is then processed into sliver using a wool blending machine, an FA103 opening machine, and an FB201 carding machine. Finally, it is produced into roving using a JWF1310 drawing frame, a JWF1310 drawing frame, and a JWF1456 roving frame. Details are as follows: Cashmere and silk are cut and then weighed and mixed in a 50 / 50 ratio. They are then sprayed with wool-refining oil and antistatic agent, and covered with plastic film for 24 hours. The wool-refining machine, FA103 type opening machine, and FB201 type carding machine are used to make cotton slivers with a basis weight of 20.3g / 5m. The first drawing weight is 21.2g / 5m and the speed is 300m / min. The second drawing weight is 19.5g / 5m and the speed is 300m / min. The JWF1456 type roving frame has a basis weight of 4.9g / 10m and a spindle speed of 950r / min.

[0026] (iv) Preparation of outer layer yarn C: Water-soluble vinylon filament and ultrafine polyester filament were wound at a speed of 600 m / min using an NF620 winding machine, and then twisted again using an NF310AB chemical fiber doubling twister at a spindle speed of 5000 r / min and a twist of 80 twists / 10 cm (twist coefficient approximately 440). The twisted yarn was then fed into a hot air setting machine for dry heat setting at 130℃ for 40 minutes. The resulting twisted yarn had a stable twist, and the linear density ratio of water-soluble vinylon to polyester was 1:2.4.

[0027] (v) Fine yarn spinning: A modified JWF1576 spinning frame is used. Spindle speed is 8000~16000 r / min, roller spacing: 20mm front zone × 46mm back zone, ring type PG2-4554, twist coefficient 250~360. Core yarn A is fed from the middle of the back roller, rovings B1 and B2 are fed from the middle roller and positioned on either side of yarn A, and twisted yarn C is fed from the gathering roller, maintaining a 3~4mm gap with the AB mixed sliver. The yarn is then twisted and wound into yarn.

[0028] (vi) Post-processing: The yarn is spun into skeins (150g per skein) using a spinning machine (speed 800~1200m / min) and a yarn reeling machine. The skeins are then placed in a skein dyeing machine, heated from room temperature to 100℃ for 40 minutes and held at that temperature for 60 minutes. Subsequently, the yarn is centrifuged to remove water (800r / min for 15 minutes) and then dried (80℃ for 8 hours).

[0029] (vii) Product appearance: Yarn structure observation shows that the high-shrinkage acrylic core yarn is concentrated in the center of the yarn, while the intermediate layer fibers composed of modal and cashmere / silk are squeezed outwards to form a distinct bulky layer. The ultrafine polyester filaments are wound in a spiral bend around the yarn surface, forming localized knots ("braids"), with an average spacing of approximately 20 mm between the knots. The yarn has a soft and fluffy feel, and a silky smooth texture.

[0030] Example 2 This embodiment is basically the same as Embodiment 1, except that the heat setting temperature of the outer twisted yarn is 120°C.

[0031] The resulting yarn exhibited a similar surface twisting effect to that of Example 1, with intact filament spiral morphology, and its product performance indicators were essentially consistent with those of Example 1. This indicates that the heat setting temperature has little effect on the final result within the range of 120~140℃.

[0032] Example 3 This embodiment is basically the same as Embodiment 1, except that the heat setting temperature of the outer twisted yarn is 140°C.

[0033] The resulting yarn exhibits a similar surface twisting effect to that of Example 1, with a complete filament spiral morphology, and its product performance indicators are essentially consistent with those of Example 1. This indicates that the setting effect is stable within the temperature range of 120~140℃.

[0034] Example 4 This embodiment is basically the same as embodiment 1, except that after the yarn is put into the yarn dyeing machine, the temperature is raised from room temperature to 80°C and kept warm for 90 minutes.

[0035] Example 5 This embodiment is basically the same as Embodiment 1, except that the water-soluble vinylon filament is 30D / 10f and the ultrafine polyester filament is 60D / 130f, with a linear density ratio of 1:2.

[0036] The resulting yarn, after the water-soluble vinylon was dissolved, showed a slightly higher release twist of the polyester filaments than in Example 1. The average knot spacing was 14 cm, and the number of knots reached 7.5 per meter, indicating a denser knotting effect than in Example 1.

[0037] Example 6 This embodiment is basically the same as Embodiment 1, except that the ultrafine polyester filament specification is 120D / 288f and the linear density ratio is 1:4.

[0038] The resulting yarn exhibits a twisted shape ("braid-like"), with an average spacing of approximately 30 mm between the twists, resulting in a sparser twisting effect compared to Example 1.

[0039] The number of knots here can be controlled by the degree of twist; a larger twist results in more knots, and vice versa.

[0040] Comparative Example 1 This comparative example is basically the same as Example 1, except that B1 yarn uses the same cashmere / silk (50 / 50) as B2 yarn.

[0041] Comparative Example 2 This comparative example is basically the same as Example 1, except that B2 yarn uses the same modal roving as B1 yarn.

[0042] Comparative Example 3 This comparative example is basically the same as Example 1, except that B2 yarn is made of cashmere roving.

[0043] Comparative Example 4 This comparative example is basically the same as Example 1, except that B2 yarn is made of silk roving.

[0044] Comparative Example 5 This comparative example is basically the same as Example 1, except that the linear density ratio of water-soluble vinylon filament to ultrafine polyester filament is 1:1.

[0045] Comparative Example 6 This comparative example is basically the same as Example 1, except that step (iv) of dry heat setting of the outer yarn C was not performed.

[0046] Comparative Example 7 This comparative example is basically the same as Example 1, except that the outer yarn C does not contain water-soluble vinylon filaments.

[0047] Comparative Example 8 This comparative example is basically the same as Example 1, except that the outer yarn C is made of spandex-covered yarn, wherein the core yarn of the spandex-covered yarn is spandex filament and the covering yarn is nylon filament.

[0048] Performance testing: The yarns prepared in the above embodiments and comparative examples were tested for yarn linear density, linear density coefficient of variation, single yarn breaking strength, single yarn breaking strength coefficient of variation, bulking rate, abrasion resistance, and kink number. The results are shown in Table 1. Among them: The yarn linear density, coefficient of variation of linear density, single yarn breaking strength, and coefficient of variation of single yarn breaking strength are tested in accordance with the GB / T398-2018 standard for the quality of natural cotton yarn. The bulking rate was measured by comparing the yarn before and after treatment. The change in mass per 100 meters of 10-skein yarn before and after bulking was tested, and the calculation formula is as follows: Bulking rate = (Mass per 100 meters after treatment - Mass per 100 meters before treatment - Mass per 100 meters of water-soluble fiber) / Mass per 100 meters before treatment × 100%; The abrasion resistance test was conducted according to FZ / T01058-1999 "Test Method for Abrasion Resistance of Yarn - Reciprocating Roller Method", using an LFY-109A computerized yarn abrasion tester, with 20 yarn segments tested in each test. The number of knots was counted manually by visual inspection, observing the number of knots in 1 meter of yarn, and calculating the average value for 5 meters of yarn for each variety.

[0049] Table 1. Test results for each embodiment and comparative example.

[0050] As shown in Table 1, Examples 2 and 3 only changed the heat setting temperature of the outer twisted yarn, which had little impact on the performance indicators of the yarn; Example 4 changed the dyeing temperature, which resulted in a smaller shrinkage rate of the heat-shrinkable fiber, a decrease in bulkiness, a decrease in the number of kinks, and a larger single yarn strength; Examples 5 and 6 changed the ratio of polyester fiber to water-soluble fiber in the twisted yarn. As the proportion of water-soluble fiber decreased, the number of kinks showed a downward trend. In Table 1, the fiber raw materials of B1 and B2 were adjusted in Comparative Examples 1, 2, 3, and 4. Since the fiber raw materials selected in this invention are all relatively soft, these adjustments did not result in significant changes to the various indicators in Table 1. However, in Comparative Example 5, the ratio of water-soluble fiber to polyester filament was adjusted to 1:1, which led to a sharp increase in the number of twists and a decrease in abrasion resistance. In Comparative Example 6, no heat twisting was performed on the outer yarn, resulting in an increase in the number of twists to 28 per meter and a decrease in abrasion resistance. In Comparative Example 7, no water-soluble filament was used. After the outer yarn was twisted, the lack of water-soluble fiber dissolution created gaps, preventing the formation of twists, but the yarn strength increased significantly. In Comparative Example 8, spandex filament was used instead of water-soluble fiber. After the spandex fiber shrank, the nylon filament tightly wrapped around the spandex filament. Because the elasticity of the spandex filament improved the tightness of the bulky yarn, the abrasion resistance increased dramatically.

[0051] Therefore, experiments show that in the twisted yarn of the outer layer, after the water-soluble filaments dissolve, the polyester filaments locally shrink and twist. The higher the proportion of water-soluble fibers, the larger the gaps formed after dissolution, and the easier it is to form twists; conversely, the lower the proportion, the less likely it is to form twists. The bulkiness of the yarn is mainly related to the post-treatment temperature of the heat-shrinkable fibers. The higher the temperature, the greater the heat shrinkage and the higher the bulkiness. The linear density of the yarn is related to the bulkiness. The higher the bulkiness, the greater the linear density of the yarn. In the outer layer yarn, the composition of filament fibers has a significant impact on the single yarn strength. The lower the proportion of water-soluble fibers, the greater the single yarn strength. There are many factors affecting abrasion resistance. When the proportion of water-soluble fibers is constant, high bulkiness results in poor abrasion resistance. When the proportion of water-soluble fibers in the outer layer yarn decreases or even disappears, the abrasion resistance gradually improves. In summary, the key technical features included in the technical solution of this invention—including but not limited to: the separate preparation of the three-layer structure and multi-channel composite spinning, the high-temperature twisting and heat setting process of the outer filament, the specific linear density ratio of water-soluble vinylon and polyester filament, and the temperature control in the finishing process—are all necessary to achieve the technical effects described in this invention. Moreover, there is a synergistic relationship between these features, which have outstanding substantive characteristics. The resulting bulky yarn has excellent bulky properties, silky feel, surface abrasion resistance, and unique appearance, which broadens the product application range of bulky yarn and represents a significant improvement.

Claims

1. A production process for composite structure bulky yarn, characterized in that, Includes the following steps: S1. Preparation of composite structure yarn The core roving, intermediate roving, and outer twisted yarn are simultaneously fed into a spinning machine to obtain a composite structure yarn. The core roving is fed from the back roller, the intermediate roving is fed from both sides of the core roving from the middle roller, and the outer twisted yarn is fed between the front roller and the middle roller, maintaining a certain distance from the intermediate roving sliver during feeding. The core roving is made from high-shrinkage acrylic fibers through a roving process, and the intermediate roving is made from low-shrinkage fibers through a roving process. The shrinkage rate of the low-shrinkage fibers is lower than that of the high-shrinkage acrylic fibers. The low-shrinkage fibers include first core yarn fibers and second core yarn short fibers. The outer twisted yarn is a combined twisted yarn of water-soluble vinylon filament and ultrafine polyester filament, and is subjected to dry heat setting treatment; S2, Prepare composite structure bulky yarn. The composite structure yarn obtained in step S1 is treated in hot water at a temperature lower than the dry heat setting temperature. This causes the water-soluble vinylon filament to dissolve and the high-shrinkage acrylic fiber to undergo thermal shrinkage. After the water-soluble vinylon filament dissolves, the ultrafine polyester filament releases its twist and is wound around the yarn surface in a spiral bending state, with some sections forming a twisted structure, thus obtaining the composite structure bulky yarn.

2. The production process according to claim 1, characterized in that, The first core yarn fiber is modal fiber, and the second core yarn short fiber is a mixture of cashmere and silk short fibers.

3. The production process according to claim 1, characterized in that, The dry heat setting temperature is 120~140℃.

4. The production process according to claim 1, characterized in that, The hot water temperature in step S2 is 80~100℃, which is higher than the water solubility temperature of water-soluble vinylon filament.

5. The production process according to claim 1, characterized in that, The linear density ratio of the water-soluble vinylon filament to the ultrafine polyester filament is 1:2~4.

6. The production process according to claim 1, characterized in that, In step S2, the composite structure yarn is subjected to hot water treatment in the form of skein yarn.

7. A composite structure bulky yarn, characterized in that, It is produced by the manufacturing process according to any one of claims 1-6, comprising: The core yarn (A) is composed of high-shrinkage fibers; the intermediate layer yarn, which covers the outer periphery of the core yarn, is composed of low-shrinkage fibers. The outer filament (C) covers the outer periphery of the middle layer yarn and is composed of ultrafine polyester filaments; the ultrafine polyester filaments are wound around the yarn surface in a spiral bending state, and some sections form a twisted structure. The core yarn shrinks and concentrates at the center of the yarn after heat shrinkage, forcing the middle layer yarn and the outer layer filament to bulge outward to form a bulky structure.

8. The composite structure bulky yarn according to claim 7, characterized in that, The high-shrinkage fiber is a high-shrinkage acrylic fiber with a specification of 1.5~2.4 dtex and a fiber length of 65~80 mm.

9. The composite structure bulky yarn according to claim 7, characterized in that, The intermediate layer yarn includes at least two rovings, which are made of different fiber materials.

10. The composite structure bulky yarn according to claim 9, characterized in that, The intermediate layer yarn comprises a first roving (B1) made of modal fibers and a second roving (B2) made of a blend of cashmere and silk.

Images