Warm-keeping yarn as well as preparation method and application thereof

Abstract

The invention discloses a warm-keeping yarn which at least contains a fiber bundle with the hollowness of 5-25%, and the fiber bundle at least contains two kinds of fibers with shrinkage rate difference. According to the invention, the fibers with fineness and shrinkage difference and a specific spinning process are combined to prepare the spun yarn with hollowness, so that the lightweight and warm-keeping yarn is provided, and the problem that the wearing comfort and the warm-keeping property cannot be considered at the same time in the prior art is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of spinning, and in particular relates to a yarn with high hollowness and high warmth retention, and a preparation method and application thereof. Background Art

[0002] Warmth retention is one of the essential functions for autumn and winter clothing. Knitted thermal underwear also has an industry standard "FZ / T 73022-2019 Knitted Thermal Underwear" requiring a heat retention rate of ≥30%. Traditional thermal fabrics achieve a warming effect by increasing the thickness of the fabric. Generally speaking, when the weight is 300-350g / m 2 At the same time, although the fabric has good warmth retention, it is not comfortable to wear. Therefore, lightweight warm products have become a new development direction.

[0003] For example, patent CN211005787U discloses an acrylic blended thermal bulked yarn, which is made of high shrinkage core yarn, consolidation yarn and velvet yarn, which are twisted together. The core yarn is high shrinkage acrylic fiber, the consolidation yarn is high strength elastic filament, and the velvet yarn uses camel hair as velvet to obtain a warming effect. However, camel hair is very expensive, and the production cost of the three yarns twisted together is also very high, so there are problems in market application.

[0004] For another example, patent CN217418909U discloses a thermal bulked yarn and woven fabric, the yarn includes a yarn core and an outer yarn twisted therewith, the shrinkage rate of the yarn core is greater than that of the outer yarn, the outer yarn forms a plurality of convex circles on the outer peripheral wall of the yarn core, and conductive fibers are spirally wound between the yarn core and the outer yarn. The yarn core is false-twisted by high-efficiency thermal fiber and bamboo fiber twisted yarn, and the outer yarn is twisted by cotton fiber to obtain a thermal insulation effect. However, the yarn has a complex structure and is difficult to produce on conventional equipment, and the bulkiness of the yarn is affected after the twisting process, which also reduces the thermal insulation effect. Summary of the invention

[0005] In view of the shortcomings of the prior art mentioned above, the purpose of the present invention is to provide a yarn with high hollowness and high warmth retention, and a preparation method and use thereof, so as to solve the problem that the yarn in the prior art cannot simultaneously meet the requirements of being warm and lightweight, and having a simple preparation method and stable performance.

[0006] To achieve the above objectives and other related objectives, the present invention is achieved through the following technical solutions.

[0007] A first aspect of the present invention provides a thermal yarn, wherein the yarn comprises at least one fiber bundle with a hollowness of 5 to 25%, and the fiber bundle comprises at least two fibers with different shrinkage rates.

[0008] When the hollowness is lower than 5%, the static air content in the fiber bundle is too low and the thermal insulation effect is limited; when the hollowness is greater than 25%, the anti-extrusion performance is poor during the yarn weaving and fabric dyeing and finishing process, resulting in a decrease in the final thermal insulation effect.

[0009] Fiber shrinkage refers to the ability of yarn to shrink along the length direction due to heat and moisture during processing. In actual yarn application, shrinkage is often reflected in the dyeing and finishing stage.

[0010] Preferably, the ratio of shrinkage rates of the fibers to each other is 4 to 15. For example, it may be 4 to 7, 7 to 10, 10 to 13, 13 to 15. In some specific embodiments, it is 6, 12, or 15.

[0011] In the actual dyeing and finishing process, the fibers with high shrinkage tend to transfer and shrink toward the core, driving the fibers with low shrinkage on the surface to arch and bend, forming regularly distributed convex parts, increasing the gaps between the fibers, and thus achieving high fluffiness. When the shrinkage ratio of the two fibers is less than 4, the shrinkage difference is too small, and it is difficult to form obvious convex parts on the surface of the yarn; when the shrinkage ratio of the two fibers is higher than 15, the number of convex parts formed on the surface of the yarn is too high, and the anti-extrusion ability of the yarn becomes poor, which is not conducive to improving fluffiness.

[0012] More specifically, among the two raw materials fibers having different shrinkage rates, the raw material fiber with low shrinkage rate includes one or more of acrylic fiber, wool, cashmere, kapok fiber, aerogel fiber, cotton, viscose, modal, lyocell, polyester and nylon.

[0013] Preferably, fibers with low thermal conductivity, such as acrylic, wool, cashmere, etc., can further reduce heat loss; further preferred are fibers that contain still air, such as hollow polyester fibers, hollow viscose fibers, hollow acrylic fibers, kapok fibers and aerogel fibers, etc., thereby forming an outer shell with still air on the surface of the yarn, thereby improving the thermal insulation effect.

[0014] The raw material fibers with high shrinkage include one or more of high shrinkage polyester fibers, high shrinkage acrylic fibers, and SORONA fibers.

[0015] Preferably, the fineness ratio of the fibers is 1.0 to 2.5. More preferably, the fineness ratio is 1.2 to 2.5, such as 1.2 to 1.4, 1.4 to 1.6, 1.6 to 1.8, 1.8 to 2.1, and 2.1 to 2.5. In some specific embodiments, it is 1.2, 2.0, and 2.3. The size of this ratio will affect the transfer ability of the two fibers in the yarn during spinning and dyeing and finishing. When the fineness ratio is lower than 1.2 times, the fineness of the low and high shrinkage single fibers is basically the same, and it is difficult for the fibers with high shrinkage to transfer to the core during spinning and dyeing and finishing. When the fineness ratio is higher than 2.5 times, although it is conducive to the transfer of fibers with high shrinkage to the core, the diameter of the fibers with low shrinkage is large, the number of fibers per unit cross section is small, and the warmth retention of the yarn is poor. On the other hand, the increase in the diameter of the fibers with low shrinkage will also increase the rigidity of the fibers, making it difficult to arch and bend, which is not conducive to the formation of convex parts.

[0016] Preferably, the hollowness of the fiber bundle refers to the ratio of the cross-sectional area of ​​the hollow space in the cross section of the fiber bundle to the apparent cross-sectional area of ​​the fiber bundle.

[0017] Preferably, after treatment in 100°C boiling water, the number of convex parts on the surface of the yarn is 400 to 1000 per meter. More preferably, it is 400 to 900 per meter, such as 400 to 600 per meter, 600 to 800 per meter, 800 to 900 per meter. In some specific embodiments, it is 700 per meter or 950 per meter. The number of convex parts on the surface is also an important factor affecting the amount of static dry air contained in the fabric. When the number of convex parts is less than 400 per meter, the convex parts on the surface of the yarn are too few, the fluffiness is low, and the warmth retention effect is poor. When the number of convex parts is greater than 900 per meter, the number of convex parts on the surface of the yarn is too many, the volume of a single convex part is small, and the gap between adjacent convex parts becomes smaller, so that the yarn has low fluffiness and is not conducive to heat insulation.

[0018] Preferably, after treatment in 100°C boiling water, the ratio of the diameter of the convex part to the concave part of the yarn surface layer is 1.2-2.5. More preferably, it is 1.3-2.5, such as 1.3-1.5, 1.5-1.8, 1.8-2.1, 2.1-2.5. Particularly preferably, it is 1.5-2.2. In some specific embodiments, it is 1.2, 2.0, 2.3. This ratio is an important factor affecting the amount of static dry air contained in the fabric. When the ratio of the diameter of the convex part to the concave part is lower than 1.3, the height of the convex part of the yarn surface layer is small, the static dry air inside is small, and the bulkiness of the yarn and the fabric is poor. When the ratio of the diameter of the convex part to the concave part is greater than 2.5, the height of the convex part of the yarn surface layer is too high, and its compression recovery is poor, and the bulkiness of the fabric after production and processing is also poor.

[0019] Preferably, the hollowness of the fiber bundle is achieved by one or more of the following methods: a) using hollow fibers; b) using non-hollow special-section fibers; c) using soluble raw fiber; d) using raw fiber of fine denier acrylic fiber, wool fiber, three-dimensional curled synthetic fiber; e) using flat fiber.

[0020] More specifically, the hollow fiber is selected from one or more of hollow chemical fibers, hollow natural fibers and aerogel fibers.

[0021] Preferably, in the method for preparing the warm yarn, when hollow fibers are used as raw material fibers, the raw material fibers have inherent hollowness, and the yarn is formed through the steps of blending, carding, drawing, roving and spinning. Thus, through the hollow fibers and their dosage and the method for preparing the yarn, there is at least one fiber bundle formed by the hollow fibers with a hollowness of 5 to 25% in the yarn.

[0022] More specifically, the non-hollow special-shaped cross-section fiber is one or more selected from dumbbell-shaped, C-shaped, cross-shaped, L-shaped, and swastika-shaped.

[0023] Preferably, in the preparation method of the warm yarn, when non-hollow shaped cross-section fibers are used as raw material fibers, during the process of the raw material fibers being formed into spun yarn through the steps of blending, carding, drawing, roving and spinning, due to the shaped cross-section and mutual embracing, hollow spaces are formed between the fibers, thereby forming a certain hollowness. Thus, through the non-hollow shaped cross-section fibers and their dosage and the spun yarn preparation method, at least one fiber bundle formed by the non-hollow shaped cross-section fibers with a hollowness of 5 to 25% exists in the final spun yarn.

[0024] Preferably, in the preparation method of the warm yarn, when using fibers with good bulkiness as raw materials, in the process of forming the spun yarn through the steps of blending, carding, drawing, roving and spinning, the fluffy fibers are irregular, and they also present a special-shaped cross-section and embrace each other during the preparation process, and hollow spaces are formed between the fibers to form a certain hollowness. Thus, through the fibers with good bulkiness and their dosage and the spun yarn preparation method, at least one fiber bundle with a hollowness of 5 to 25% formed by the fibers with good bulkiness is present in the final spun yarn. The fibers with good bulkiness are selected from one or more of fine-denier acrylic fibers, wool fibers, and three-dimensional curled synthetic fibers.

[0025] Preferably, in the method for preparing the warm yarn, when flat fibers are used as raw materials, during the process of forming the spun yarn through the steps of blending, carding, drawing, roving and spinning, the flat fibers are mutually embraced with other fibers during the preparation process, and hollow spaces are formed between the fibers, thereby forming a certain hollowness. Thus, through the flat fibers and their dosage and the spun yarn preparation method, at least one fiber bundle formed by the flat fibers with a hollowness of 5 to 25% exists in the final spun yarn.

[0026] In a preferred technical solution using soluble fiber as raw material fiber, the yarn is spun so that the soluble fiber is located in the middle of the yarn. Specifically, the soluble fiber is first made into strips by combing cotton; then the strips containing soluble fiber are placed in the middle position and combined with other raw material fiber strips in the final drawing process, and then the slivers containing soluble fiber are passed through the roving and spun yarn processes to prepare the spun yarn with the soluble fiber located in the middle. In a specific embodiment, the soluble fiber is soluble vinylon. In the subsequent application stage of the spun yarn, the soluble fiber is dissolved to form a certain hollowness. Generally speaking, it is specifically in the dyeing and finishing process. In order to ensure that the final spun yarn contains at least one fiber bundle with a hollowness of 5 to 25%, and at the same time can ensure the application performance of the spun yarn such as strength, the raw material fiber, in addition to the soluble fiber, also uses one or more selected from hollow fibers, non-hollow special-shaped cross-section fibers, flat fibers or fluffy fibers. The fluffy fiber is selected from one or more of fine denier acrylic fibers, wool fibers, and three-dimensional curled synthetic fibers.

[0027] Preferably, the fiber bundle containing hollowness is used in an amount of at least 50 wt %, based on the mass of the yarn.

[0028] The second aspect of the present invention further discloses a method for preparing the above-mentioned warm yarn, the preparation method comprising the following steps:

[0029] 1) Blending: The raw fibers are fully opened, impurities removed, and mixed evenly, and the basis weight of the cotton roll is 310-450 g / m; the raw fibers contain at least two fibers with different shrinkage rates;

[0030] 2) Carding: Carding forms carded slivers with a basis weight of 15-25g / 5m;

[0031] 3) Drawing: Drawing is done to form mature strips, the weight of the mature strips is 10-25g / 5m;

[0032] 4) Roving: The sliver is drawn, twisted and wound into warm roving, with a basis weight of 2-6g / 5m and a twist of 2-8 twists / 10cm;

[0033] 5) Spun yarn: the siro spinning process is adopted, the spun yarn count is 16-80S, and the spun yarn twist coefficient is set to 250-400; the spun yarn obtained after the spinning process contains at least one fiber bundle with a hollowness of 5-25%;

[0034] 6) Winding.

[0035] Preferably, a roving sliver having a certain hollowness is formed through the roving process.

[0036] Preferably, in 2) the carding process, the carding speed is 50-80 m / min.

[0037] Preferably, in the 3) drawing process, the drafting multiple in the back zone is 1.2 to 1.7; in order to retain the fluffiness of the sliver, the diameter of the drawing bell mouth is one size larger than that of conventional chemical fibers.

[0038] Preferably, for 4) the roving process, the total draft is 5-12 times.

[0039] Preferably, in 5) the spun yarn process, the diameter of the double bell mouth of the siro spinning is 1.8-3.5 mm, the spacing is 2.0-4.0 mm, and the total draft is 20-80 times.

[0040] Preferably, the preparation method further comprises pre-treatment of raw fiber, using a smoothing agent and an antistatic agent to treat the fiber with high shrinkage and / or soluble fiber. Specifically, the treatment refers to applying the smoothing agent and the antistatic agent, and letting the smoothing agent stand for at least 6 hours. In a preferred embodiment, the smoothing agent is a hydrophilic soft smoothing agent HS05, and the amount applied is 1 to 5wt% of the mass of the raw fiber to be applied. In a preferred embodiment, the antistatic agent is TF-480A, and the amount applied is 1 to 5wt% of the mass of the raw fiber to be applied. Preferably, the standing time is at least 12 hours.

[0041] The third aspect of the present invention provides use of the above-mentioned warming yarn in weaving a warming fabric.

[0042] A fourth aspect of the present invention provides a fabric which is woven at least with the warm-keeping yarn as described above.

[0043] As described above, the present invention provides a thermal yarn, a preparation method and use thereof. The applicant of the present application prepares a fine yarn with high or medium hollowness by selecting fibers with different fineness and shrinkage rates and a specific spinning process, thereby providing a lightweight and thermal yarn, solving the problem in the prior art that both wearing comfort and thermal insulation cannot be taken into account.

[0044] The beneficial effects of the present invention include the following aspects:

[0045] 1) The thermal insulation yarn provided by the present invention has a simple structure, a simple preparation process, and can be realized using conventional designs, and has high operability.

[0046] 2) The thermal insulation yarn provided by the present invention has the characteristics of high hollowness and excellent thermal insulation effect. It can also improve the thickness and fluffiness of conventional fabrics in the prior art, and has the effects of being light, fluffy and warm. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram showing the effect of yarn shrinkage in this embodiment 1. DETAILED DESCRIPTION

[0048] The following is an explanation of the embodiments of the present invention by specific examples to verify the practical feasibility of the method of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0049] It should be noted that the process equipment or devices not specifically noted in the following embodiments are all conventional equipment or devices in the art. In addition, it should be understood that one or more method steps mentioned in the present invention do not exclude the presence of other method steps before and after the combination step or the insertion of other method steps between these explicitly mentioned steps, unless otherwise specified. Moreover, unless otherwise specified, the numbering of each method step is only a convenient tool for identifying each method step, and is not intended to limit the order of arrangement of each method step or to limit the scope of the present invention. The change or adjustment of the relative relationship thereof shall also be regarded as the scope of the present invention without substantially changing the technical content.

[0050] In the following specific embodiments of the present application, the hollowness of the fiber bundle is achieved by one or both of the following methods: a) using hollow fibers; b) using a fiber bundle with hollowness.

[0051] Preferably, the hollow fiber includes one or more of hollow chemical fiber, hollow natural fiber and aerogel fiber. In a specific embodiment, it is hollow cationic polyester.

[0052] The fiber bundle is twisted in the spinning stage. In the following specific embodiment, two rovings with a certain hollowness are selected, and the yarn formed has two bundles of hollow fiber bundles. In addition, it is also possible to use a roving with a certain hollowness and a conventional roving without hollowness, and the yarn formed has only a single bundle of hollow fiber bundles.

[0053] Example 1

[0054] In this embodiment, a warm yarn is provided, which is composed of 70% dumbbell-shaped acrylic fiber and 30% high shrinkage acrylic fiber. The raw material fibers are: 1.0D*38mm dumbbell-shaped acrylic fiber with a fiber shrinkage rate of 2.5%; 1.0D*38mm high shrinkage acrylic fiber with a fiber shrinkage rate of 15%.

[0055] The spinning process includes fiber pretreatment, blending, carding, drawing, roving, spinning and winding. Among them, the yarn count is 40S and the twist coefficient is set to 350.

[0056] The specific steps of the preparation method include the following:

[0057] (1) Fiber pretreatment

[0058] In order to improve the transfer effect of high shrinkage acrylic fiber in the spinning process, it is necessary to reduce the friction coefficient and antistatic property of the fiber. The specific operation is to first use a staple fiber opener to open the high shrinkage acrylic fiber, then evenly spray 2wt% of hydrophilic softening and smoothing agent HS05 and 1wt% of antistatic agent TF-480A, and then put it in a stale place at room temperature for 24 hours.

[0059] (2) Cotton blending process

[0060] The two types of fibers are passed through a disc plucker, a multi-bin blender, a blending opener, a cotton feeder and a roll forming machine, so that each group of fibers is fully opened, impurities are removed and mixed evenly, and finally a cotton roll of uniform thickness and appropriate size is produced. In order to retain the fluffy effect of the fiber, the basis weight and length of the cotton roll are appropriately reduced, the basis weight of the cotton roll is 360g / m, and the length of the cotton roll is 42 yards.

[0061] (3) Carding process

[0062] In order to reduce fiber damage, the five-point distances from the cylinder roller to the cover plate are set larger, namely 0.25, 0.22, 0.2, 0.2, and 0.22 mm respectively. The carding speed is set to 55-70 m / min, and the sliver weight is 20 g / 5 m.

[0063] (4) Drawing process

[0064] The 8-wire combining process is adopted, the roller spacing is set to 10*20mm, the rear zone drafting multiple is 1.47, the sliver quantity is 17g / 5m, and in order to retain the fluffiness of the sliver, the diameter of the sliver bell mouth is set one size larger than that of conventional chemical fiber, and the length of the sliver on the can is set to 70% of that of conventional chemical fiber.

[0065] (5) Roving process

[0066] The process parameters of the roving are as follows: the rollers are set according to the chemical fiber gauge of 10mm*27mm*37mm, the drafting multiple of the rear zone is 1.58, the total drafting multiple is 8.5, and the roving quantity is 4.0g / 5m. In order to fully transfer the high shrinkage fiber, the twist of the roving is set to a small value, and the twist is set to 2.7 twists / 10cm.

[0067] The roving process has formed roving with a certain degree of hollowness.

[0068] (6) Spinning process

[0069] The spun yarn adopts the siro spinning process, and two coarse yarns prepared in the above steps are inserted from the back of the double bell mouth, stretched by rollers, and then twisted at the front end of the front jaw to form a hollow fiber bundle, namely the spun yarn.

[0070] The diameter of the double bell mouth is 2.5mm, the spacing is 3.0mm, the total drafting multiple is set to 54, the drafting multiple of the rear zone is 1.25, the spun yarn count is 40S1, and the spun yarn twist coefficient is set to 350. In order to prevent the high shrinkage fiber transferred into the yarn from transferring outward during the twisting process, a false twist device is added to the front end of the front roller to complete the twisting action in advance. The running speed of the false twist strip is 1.2 times the output speed of the front roller.

[0071] In the spinning stage, a stable hollow fiber bundle is formed by twisting, and the yarn has a total of 2 fiber bundles.

[0072] (7) Winding process

[0073] The winding speed is controlled at 1000m / min.

[0074] Figure 1 The diagram shows the effect of yarn shrinkage in Example 1. After being treated with 100°C boiling water, the yarn was tested using an optical microscope with a magnification of 10 times.

[0075] Example 2

[0076] In this embodiment, a warm yarn is provided, which is composed of 70% dumbbell-shaped acrylic fiber and 30% high shrinkage acrylic fiber. The raw material fibers are: 1.5D*38mm dumbbell-shaped acrylic fiber with a fiber shrinkage rate of 2.5%; 1.0D*38mm high shrinkage acrylic fiber with a fiber shrinkage rate of 15%.

[0077] The spinning process and specific steps are exactly the same as those in Example 1.

[0078] Example 3

[0079] In this embodiment, a warm yarn is provided, which is composed of 70% dumbbell-shaped acrylic fiber and 30% high shrinkage acrylic fiber. The raw material fibers are: 1.5D*38mm dumbbell-shaped acrylic fiber with a fiber shrinkage rate of 2.5%; 1.0D*38mm high shrinkage acrylic fiber with a fiber shrinkage rate of 30%.

[0080] The spinning process and specific steps are exactly the same as those in Example 1.

[0081] Example 4

[0082] In this embodiment, a warm yarn is provided, which is composed of 70% dumbbell-shaped acrylic fiber and 30% high shrinkage acrylic fiber. The raw material fibers are: 1.5D*38mm dumbbell-shaped acrylic fiber with a fiber shrinkage rate of 2.5%; 1.0D*38mm high shrinkage acrylic fiber with a fiber shrinkage rate of 30%.

[0083] Except that in the siro spinning step, the yarn count is 40S and the yarn twist coefficient is set to 300, the other spinning process flows and specific steps are exactly the same as those in Example 1.

[0084] Example 5

[0085] In this embodiment, a warm yarn is provided, which is composed of 70% hollow cationic polyester and 30% high shrinkage acrylic. The raw materials are: 1.5D*38mm hollow cationic polyester, with a fiber shrinkage rate of 2.5% and a fiber hollowness of 20%; 1.0D*38mm high shrinkage acrylic, with a fiber shrinkage rate of 30%.

[0086] Except that in the siro spinning step, the yarn count is 40S and the yarn twist coefficient is set to 300, the other spinning process flows and specific steps are exactly the same as those in Example 1.

[0087] Example 6

[0088] In this embodiment, a warm yarn is provided, which is composed of 60wt% hollow cationic polyester, 30wt% high shrinkage acrylic fiber and 10wt% water-soluble vinylon, and its raw material fibers are: 1.5D*38mm hollow cationic polyester, the fiber hollowness is 20%, and the fiber shrinkage rate is 2.5%; 1.0D*38mm high shrinkage acrylic fiber, the fiber shrinkage rate is 30%; 1.0D*38mm water-soluble vinylon.

[0089] The specific steps of the preparation method include the following:

[0090] (1) First, 100% soluble vinylon is prepared into sliver A with a basis weight of 17 g / 5 m according to a conventional chemical fiber spinning process. The specific process is as follows:

[0091] (a) Fiber pretreatment

[0092] In order to improve the transfer effect of water-soluble vinylon fiber in the spinning process, it is necessary to reduce the friction coefficient and antistatic property of the fiber. The specific operation is to first use a staple fiber opener to open the water-soluble vinylon, then evenly spray 2wt% of hydrophilic softening and smoothing agent HS05 and 1wt% of antistatic agent TF-480A, and then put it in a stale place at room temperature for 24 hours.

[0093] (b) Cotton blending process

[0094] The vinyl fiber is passed through a disc cotton grabber, a multi-bin cotton mixer, a mixed cotton opener, a cotton feeder and a roll forming machine to fully loosen the vinyl fiber, and finally a cotton roll of uniform thickness and appropriate size is produced. The cotton roll has a basis weight of 420g / m and a length of 61 yards.

[0095] (c) Carding process

[0096] In order to reduce fiber damage, the 5-point distances from the cylinder roller to the cover plate are set larger, namely 0.25, 0.22, 0.2, 0.2, and 0.22 mm respectively, and the sliver weight is 20g / 5m.

[0097] (d) Drawing process

[0098] The roller spacing is set to 10mm*20mm, the drafting multiple in the rear zone is 1.47, and the weight of the second drawing is 17g / 5m.

[0099] (2) 66.7% of the hollow cationic polyester and 33.3% of the high shrinkage acrylic are mixed evenly through two mixing processes, and then carded and drawn to prepare sliver B with a basis weight of 22.5 g / 10 m.

[0100] Since the purpose of this embodiment is to transfer the water-soluble vinylon to the core of the yarn, the high shrinkage acrylic fiber is no longer pre-treated, and the cotton blending process and carding process are exactly the same as those in Example 1.

[0101] The specific drawing process is as follows: the roller spacing is set to 10mm*20mm, the rear zone drafting multiple is 1.47, the machine speed is 250m / min, the final drawing quantity is 22.5g / 5m, and in order to retain the fluffiness of the slivers, the drawing bell mouth diameter is set one size larger than that of conventional chemical fibers, and the sliver length of the sliver can is set to 70% of that of conventional chemical fibers.

[0102] (3) Final drawing process: In the final drawing process, strip A is placed in the middle, and three strips B are placed on the left and right sides. Through the final drawing process, a sliver with a skin-core structure is prepared. The weight of the sliver is 14g / 5m, the aperture of the drawing frame is set larger by 1, and the length of the sliver can is set according to 70 of the conventional chemical fiber variety.

[0103] (4) Roving process

[0104] The roving quantity is 3.5g / 5m, the total drafting multiple is 8.0, the roving twist is set smaller, and the twist is set to 3.0 twists / 10cm; the roller is based on the chemical fiber gauge of 10mm*27mm*37mm, and the drafting multiple of the back zone is 1.58.

[0105] The roving process has formed roving with a certain degree of hollowness.

[0106] (5) Spinning process

[0107] In the siro spinning process, two rovings prepared in the above steps are fed, with a double bell mouth diameter of 2.0 mm, a spacing of 3.0 mm, a total drafting multiple of 59.3 times, a rear zone drafting multiple of 1.25, a spun yarn count of 50S1, and a spun yarn twist coefficient of 320. In order to prevent the water-soluble fibers transferred into the yarn from transferring outward during the twisting process, a false twist device is added to the front end of the front roller to complete the twisting action in advance, and the running speed of the false twist strip is 1.2 times the output speed of the front roller sliver.

[0108] In the spinning stage, a stable hollow fiber bundle is formed by twisting, and the yarn has a total of 2 fiber bundles.

[0109] (6) Winding process

[0110] The winding speed is controlled at 800m / min.

[0111] Example 7

[0112] In this embodiment, a warm yarn is provided, which is composed of 30% hollow cationic polyester, 30% high shrinkage acrylic and 40% viscose. The raw materials are: 1.5D*38mm hollow cationic polyester, the hollowness of the fiber is 20%, and the fiber shrinkage rate is 2.5%; 1.0D*38mm high shrinkage acrylic, the fiber shrinkage rate is 30%; 1.5D*38mm viscose fiber, the fiber shrinkage rate is 2%.

[0113] The spinning process includes fiber pretreatment, blending, carding, drawing, roving, spinning and winding. In the spinning, the yarn count is 50S and the twist coefficient is set to 320.

[0114] The specific steps of the preparation method include the following:

[0115] (1) The fiber pretreatment is exactly the same as in Example 1.

[0116] (2) Blending process: The cotton roll weight is 380g / m and the cotton roll length is 48 yards.

[0117] (3) The carding process is exactly the same as in Embodiment 1.

[0118] (4) Drawing process: The roller spacing is set to 10mm*20mm, the drafting multiple in the rear zone is 1.47, the sliver weight is 14g / 5m, and the drawing bell mouth aperture is set larger than No. 1.

[0119] (5) Roving process: The roving quantity is 3.5g / 5m, the total draft ratio is set to 8.0, the roving twist is set to a smaller value, and the twist is set to 3.0 twists / 10cm; the roller is set according to the chemical fiber gauge of 10mm*27mm*37mm, and the draft ratio of the rear zone is set to 1.58.

[0120] The roving process has formed roving with a certain degree of hollowness.

[0121] (6) Spinning process

[0122] In the siro spinning process, two rovings prepared in the above steps are fed, with a double bell mouth diameter of 2.0 mm and a spacing of 3.0 mm. The total drafting multiple is set to 59.3, the rear zone drafting multiple is set to 1.25, the spun yarn count is 50S, and the spun yarn twist coefficient is set to a small value of 320. In order to prevent the high shrinkage fibers transferred into the yarn from transferring outward, a false twist device is added to the front end of the front roller, and the running speed of the false twist strip is 1.2 times the output speed of the front roller.

[0123] In the spinning stage, a stable hollow fiber bundle is formed by twisting, and the yarn has a total of 2 fiber bundles.

[0124] (7) Winding process

[0125] The winding speed is controlled at 800m / min.

[0126] Comparative Example 1

[0127] In this comparative example, a yarn is provided, which is composed of 70% solid acrylic fiber and 30% high shrinkage acrylic fiber. The raw material fibers are: 1.5D*38mm solid acrylic fiber with a fiber shrinkage rate of 2.5%; 1.0D*38mm high shrinkage acrylic fiber with a fiber shrinkage rate of 15%.

[0128] The spinning process and specific steps are exactly the same as those in Example 1.

[0129] Comparative Example 2

[0130] In this comparative example, a yarn is provided, which is composed of 100% hollow cationic polyester, and its raw material fiber is: 1.8D*38mm hollow cationic polyester, and the hollowness of the fiber is 30%.

[0131] In this embodiment, no fiber pretreatment process is required. Other steps are exactly the same as those in embodiment 5.

[0132] The performance tests were performed on Examples 1 to 7 and Comparative Examples 1 and 2, and the test methods were as follows:

[0133] 1) Hollowness of fiber bundle

[0134] The paraffin embedding sectioning method is used to take fiber bundles of appropriate length, and paraffin is used as the filling support medium of the fiber bundle. After the paraffin is solidified, a very thin section is taken with a slicer. The section is placed under a Keyence VHX-6000 microscope for observation, and the area of ​​the light-transmitting part of the fiber bundle cross section on the section is marked as S1, and the area of ​​the non-light-transmitting part is marked as S2. The hollowness H of the fiber bundle is calculated by the following formula. If the fiber bundle contains soluble vinylon, it must be twisted and boiled in water for 30 minutes, and then tested after drying and balancing.

[0135] Hollowness of fiber bundle:

[0136] 2) Shrinkage

[0137] In actual yarn application, shrinkage is often reflected in the dyeing and finishing stage. The dyeing and finishing shrinkage rate of yarn is the dyeing and finishing shrinkage rate of fiber.

[0138] When testing the fiber shrinkage, a single fiber was used to form a spun yarn with a count of 30S and a twist factor of 340. Specifically, the dumbbell acrylic fiber, high shrinkage acrylic fiber, hollow cationic polyester, viscose fiber, and solid acrylic fiber used in the embodiments of the present invention were tested for shrinkage.

[0139] The test method is:

[0140] a. Insert the yarn bobbin on the bobbin stand, pull out the yarn head and about 5m of yarn, fix the yarn on the clamp of the yarn length measuring instrument, wind it 10 times, and tie a knot at the head and tail to prevent it from being tangled.

[0141] b. Place the sample yarn skein under standard atmospheric conditions and equilibrate it before cooking for 8 hours.

[0142] c. Hang each sample yarn skein on the hook at the top of the vertical ruler, align the inner side of the yarn skein with the scale mark 0, hang a pre-tensioning weight at the bottom of the yarn skein, and prevent the yarn skein from twisting. After 30 seconds, align the sight with the scale mark, and accurately measure the pre-cooking length L0, accurate to 0.05cm. The pre-tension of the filament is 0.5±0.1cN / tex×number of turns×2;

[0143] d. Twist each yarn into an 8-shape, fold it in half to form a four-layer ring, wrap it with gauze, and then boil it in 100℃ boiling water for 30 minutes. Take out the gauze bag and place it horizontally, squeeze out the water, open the gauze, and place the yarn flat on the drying rack.

[0144] e. After the cooked yarn is completely dried, place it under standard atmospheric conditions and carry out post-cooking equilibrium for 8 hours.

[0145] f. Hang the upper end of the balanced yarn skein on a vertical ruler and hang the original pre-tensioned weight on the lower end. After 30 seconds, accurately measure the length L1 after boiling to an accuracy of 0.05cm.

[0146] g. Test 10 times according to the above steps and take the average value

[0147] Dyeing and finishing shrinkage calculation formula:

[0148] Where: L0--length before cooking; L1--length after cooking, unit: cm.

[0149] 3) Single fiber fineness ratio

[0150] Single fiber fineness ratio calculation formula:

[0151] Where d1 and d2 represent the diameters of different fibers; Ndt1 and Ndt2 represent the linear densities of different fibers; Y1 and Y2 represent the densities of different fibers. The linear density of the fibers is obtained by testing with an XD-1 fiber fineness meter.

[0152] 4) Number of convex parts, diameter ratio of convex parts to concave parts

[0153] The number of protrusions refers to the number of protrusions per unit length of yarn.

[0154] The ratio of the diameter of the convex part to the concave part refers to the ratio of the diameter of the most convex part of the yarn to the concave part.

[0155] The test method for the ratio of the convex part to the concave part diameter is:

[0156] a. Insert the yarn bobbin on the bobbin stand, lead out the yarn head and pull about 5m of yarn, fix the yarn on the clamp of the yarn length measuring instrument, wind it 10 times, and tie a knot at the head and tail to prevent it from being tangled.

[0157] b. Twist the yarn into an 8-shape, fold it in half to form a four-layer ring, wrap it with gauze, and then boil it in 100°C boiling water for 30 minutes. Take out the gauze bag and place it horizontally, squeeze out the water, open the gauze, and place the yarn flat on the drying rack.

[0158] c. After the cooked yarn is completely dry, place it under standard atmospheric conditions and equilibrate it for 8 hours.

[0159] d. Take three test yarn samples with a length of 15 cm at an interval of 1 meter from the balanced yarn.

[0160] e. Place it under a microscope with an eyepiece test ruler at about 10 times magnification, apply a predetermined tension, and focus to obtain the projection shape of the yarn surface. Measure the convex and concave diameters at 10 locations in the middle of each test yarn sample with a length of 1 cm as a test area. A total of 30 test data are obtained, and then the average diameter D1 of the convex part of the yarn and the average diameter D2 of the concave part are calculated.

[0161] Ratio of convex to concave diameter K:

[0162] The testing method for the number of convex parts is: while measuring the diameter of the convex part and the diameter of the concave part, the number of diameters within 1 cm greater than D2 is calculated, a total of 30 test data are obtained, and then the average value is calculated.

[0163] 5) Insulation rate

[0164] The test was carried out according to GB / T11048-1989 Method A flat plate constant temperature difference heat dissipation method.

[0165] The heat preservation rate and gram weight of the fabrics formed by the spun yarns of each embodiment and each comparative example were tested respectively.

[0166] The specific test data results are shown in Table 1 below.

[0167] Table 1

[0168]

[0169]

[0170] As can be seen from Table 1, the thermal insulation yarn provided by the present application has an excellent thermal insulation rate of up to 45% (see Example 6 for details), and has an excellent thermal insulation effect. At the same time, as can be seen from Example 1 and Comparative Example 1, Examples 3 to 5 and Comparative Example 2 in Table 1, the thermal insulation yarn provided by the present application also takes into account the customer's wearing comfort, achieves warmth and lightness, and has a better thermal insulation effect under the same yarn weight. And as can be seen from Examples 5 and 6, the thermal insulation yarn provided by the present application has a high hollowness and good thermal insulation effect, and the yarn strength meets the weaving requirements and is practical.

[0171] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A warm yarn, characterized in that: The yarn contains at least one fiber bundle with a hollowness of 5-25%, and the fiber bundle contains at least two fibers with different shrinkage rates.

2. The warm yarn according to claim 1, characterized in that: The ratio of the shrinkage of high shrinkage fiber to low shrinkage fiber is 4 to 15; And / or, the fineness ratio of the low shrinkage fiber to the high shrinkage fiber is 1.0 to 2.

5.

3. The warm yarn according to claim 1, characterized in that: After being treated in boiling water at 100° C., the number of protrusions on the surface of the yarn is 400 to 1000 per meter; And / or, after being treated in boiling water at 100° C., the ratio of the diameters of the convex parts to the concave parts on the surface of the yarn is 1.2 to 2.

5.

4. The warm yarn according to claim 1, characterized in that: The fiber bundle with a hollowness of 5 to 25% is prepared from raw material fibers selected from the following: a) hollow fibers; b) non-hollow special-shaped cross-section fibers; c) soluble raw material fibers; d) fine-denier acrylic fibers, wool fibers, three-dimensional curled synthetic fibers; and e) flat fibers.

5. The warming yarn according to claim 1, characterized in that: The fiber bundle containing hollow space is used in an amount of at least 50 wt %, based on the mass of the yarn.

6. A method for preparing the warming yarn according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: Blending: The raw fibers are fully loosened, impurities removed, and mixed evenly, and the basis weight of the cotton roll is 310-450g / m; the raw fibers contain at least two fibers with different shrinkage rates; Carding: Carding forms carded slivers with a basis weight of 15-25g / 5m; Drawing: Drawing is to form mature strips, the weight of the mature strips is 10-25g / 5m; Roving: The sliver is drawn, twisted and wound into warm roving, with a basis weight of 2.0-6.0g / 5m and a twist of 2-8 twists / 10cm; Spun yarn: The siro spinning process is used to form spun yarn, with a spun yarn count of 16-80S and a spun yarn twist coefficient of 250-400; the spun yarn obtained after the spinning process contains at least one fiber bundle with a hollowness of 5-25%; Winding.

7. The preparation method according to claim 6, characterized in that: The preparation method further comprises pre-treatment of raw material fibers, using a smoothing agent and an antistatic agent to treat fibers with high shrinkage and / or soluble fibers.

8. The preparation method according to claim 6, characterized in that: The raw material fibers are selected from: a) hollow fibers; b) non-hollow special-shaped cross-section fibers; c) soluble raw material fibers; d) fine-denier acrylic fibers, wool fibers, three-dimensional curled synthetic fibers; e) flat fibers; When the raw material fibers include soluble raw material fibers, the process further includes dissolving the soluble raw material fibers to form a fiber bundle having hollowness after forming the spun yarn.

9. Use of the warming yarn according to any one of claims 1 to 5 in weaving warming fabrics.

10. A fabric, characterized in that: The method is obtained by weaving at least the warming yarn according to any one of claims 1 to 5.

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