Loop composite yarn and method of spinning the same

Abstract

This invention belongs to the field of spinning technology and relates to a loop composite yarn and its spinning method. The spinning method involves combining a core yarn, a binder yarn, and a decorative yarn fed in by the front roller at the top of a hollow spindle. The yarn is then drawn out from the bottom of the hollow spindle by the output roller and sequentially passes through bundling, heat bonding, cooling, and winding to obtain the loop composite yarn. The binder yarn has a specific wrapping twist. T The overfeed ratio of decorative yarn is 200-300 twists / m. r The interval is 4-6; during heat consolidation, the nozzles in the heat consolidation device intermittently inject melt into the yarn; the interval between the first melt injection and the start of spinning is... t 1, t 1=( l + d ) / v 2, where, l The height of the hollow ingot, in meters (m). d The vertical distance between the hollow spindle and the nozzle is expressed in meters (m). v 2 represents the linear velocity of the output roller. v 2 is 3-5 m / min; the interval between two adjacent molten injection times is t , t =1 / ( T × v 2). The loops in the boucle composite yarn of the present invention have a larger diameter and a more stable structure.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of spinning, and relates to a loop composite yarn and a spinning method thereof. BACKGROUND

[0002] As a kind of fancy yarn, the loop yarn is generally composed of a core yarn, a decorative yarn and a fixing yarn. The core yarn is the main part of the loop yarn, the decorative yarn is the part that forms loops on the fancy twisting machine and can be a yarn of various wool spinning raw materials or a cotton spinning roving, and the fixing yarn is used to fix the loops and forms the strength basis of the loop yarn together with the core yarn. The loop yarn not only has a unique three-dimensional appearance effect, soft texture and excellent elasticity, but also is easy to be combined with other materials of different textures, thus being favored by many designers and consumers and having a broad market prospect. Therefore, it is of great significance to study the spinning process of the loop yarn.

[0003] The loop yarn is generally processed by using a hollow spindle fancy twisting machine. The core yarn is transported by a back roller and enters the hollow spindle through a guide hook. The decorative yarn enters the hollow spindle after a drafting mechanism, and the feeding speed of the decorative yarn (generally overfeed) changes regularly. The fixing yarn is drawn out from the hollow spindle tube and enters the hollow spindle together. Part of the yarn is fed simultaneously, and before the twisting hook, the core yarn and the decorative yarn are twisted together with the hollow spindle to obtain false twist, while the fixing yarn is parallel to the core yarn and the decorative yarn but not twisted. After the false twister, the false twist of the core yarn and the decorative yarn disappears, and the fixing yarn is wrapped around the core yarn and the decorative yarn to fix the pattern formed due to the overfeed change of the decorative yarn, thus forming the loop yarn. The core yarn needs a certain tension, the decorative yarn needs overfeed, and the fixing yarn must be wrapped.

[0004] When the loop yarn is spun, the diameter and density of the loops formed and the fastness are affected by many factors such as the overfeed ratio of the decorative yarn, the wrapping twist of the fixing yarn, etc. The overfeed ratio of the decorative yarn is the ratio of the output speed of the decorative yarn to the output speed of the core yarn. When the speed ratio of the front roller to the core yarn feeding is small, the overfed decorative yarn is too little to form a pattern and cannot be made into a loop yarn. When the speed ratio of the front roller to the output roller is large, the overfed decorative yarn is too much, and the yarn structure is too loose, which also cannot be made into a loop yarn. The wrapping twist of the fixing yarn = the speed of the hollow spindle / the linear speed of the output roller. When the linear speed of the output roller is fixed, the speed of the hollow spindle is proportional to the wrapping twist of the fixing yarn. With the increase of the speed of the hollow spindle, the wrapping twist of the fixing yarn also gradually increases, and more loops are distributed on the yarn per unit length, so the density of the loops gradually increases and the diameter of the loops gradually decreases. Conversely, the wrapping twist of the fixing yarn decreases, the loops are looser, and the diameter of the loops increases.

[0005] However, existing technologies are generally unable to spin boucle yarns with large diameters and stable structures. For example, Reference 1 (Development of New Two-Color Boucle Wave Composite Fancy Yarn [D]. Shanghai: Donghua University, 2014: 23.) proposes that when boucle yarn is spun using only a hollow spindle fancy twisting machine, the boucles are unstable and easily slip off the yarn when the hollow twist is less than 350; when the hollow twist is higher than 475, the boucles are wrapped inside the yarn backbone, the boucles cannot expand, and the yarn shape begins to deteriorate. This is because when the hollow twist is small, the diameter of the boucles is large, the decorative yarn is easy to slip off, the overall structural stability of the yarn deteriorates, and it cannot be spun into yarn; Reference 2 (Influence of Boucle Yarn Spinning Process on Fabric Appearance and Performance [J]. Journal of Basic Science of Textile Colleges, 2024, 37(06):76-82.) proposes that when the overfeed ratio is greater than 2.4, there is too much overfeed decorative yarn, the yarn structure is too loose, and it cannot be spun into boucles. Therefore, when spinning boucle yarn using existing technology, when the diameter of the boucle reaches 4mm, the resulting boucle shape is messy and the structure is difficult to maintain stability.

[0006] In summary, it is necessary to develop a new type of boucle composite yarn and its spinning method to form boucle yarn with a larger diameter and more stable structure. Summary of the Invention

[0007] The purpose of this invention is to solve the problems existing in the prior art and to provide a boucle composite yarn and its spinning method.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A method for spinning boucle composite yarn involves combining the core yarn, the binding yarn, and the decorative yarn fed in by the front roller at the top of a hollow spindle. The yarn is then drawn out from the bottom of the hollow spindle by the output roller and sequentially passes through bundling (the purpose of which is to reduce the bulkiness of the yarn and ensure the quality of the binding point during subsequent heat binding), heat binding, cooling, and winding to obtain boucle composite yarn.

[0010] Among them, the fiber length of the decorative yarn is 60-120mm, the twist of the fixed yarn wrapping T is 200-300 twists / m, and the overfeed ratio of the decorative yarn r is 4-6;

[0011] During thermal consolidation, the nozzles in the thermal consolidation device intermittently spray melt onto the yarn;

[0012] The interval between the first injection of melt and the start of spinning is t1, where t1 = (l + d) / v2, l is the height of the hollow spindle in meters, d is the vertical distance between the hollow spindle and the nozzle in meters, and v2 is the linear velocity of the output roller, which is 3-5 m / min.

[0013] The interval between two consecutive injections of melt is t, where t = 1 / (T × v2).

[0014] The principle of this invention is as follows:

[0015] When spinning boucle yarn, on a hollow spindle fancy twisting machine, the overfeed ratio r of the decorative yarn reaches 4-6, the twist T of the fixed yarn reaches 200-300 twists / m, and the linear speed v2 of the output roller reaches 3-5m / min. According to the boucle yarn formation process L=(r-1) / T, the theoretical circumference L of the formed boucle can reach 15-17mm, and the equivalent diameter can reach 4.7-5.3mm. With this size of boucle, due to the small twist of the fixed yarn, the overall structure of the yarn is loose, the decorative yarn is easy to slip off the yarn body, and the shape of the boucle is difficult to maintain stably.

[0016] This invention, while spinning boucle yarn, utilizes a thermal consolidation device to solidify the formed boucles at the points where they connect with the yarn body. Specifically, this invention sets the interval between the first melt injection moment and the spinning start moment to t1, where t1 = (l + d) / v2. This is because when spinning on a hollow spindle fancy twisting machine, the entanglement of the fixed yarn with the decorative yarn and core yarn occurs at the top of the hollow spindle. Setting the interval between the first melt injection moment and the spinning start moment to t1 ensures that the first solidification position of the yarn body coincides with the first entanglement position. Furthermore, the interval between two subsequent melt injection moments is t = 1 / (T × v2), which also aims to ensure that the solidification position coincides with the entanglement position each time. This ensures that both ends of the formed boucle composite yarn boucles are fixed at the solidification point, preventing the boucles and fixed yarn from slipping off.

[0017] Furthermore, the fiber length of the decorative yarn used in this invention to form the loops is 60-120mm, which is much longer than the theoretical circumference of the formed loops, thus ensuring the integrity of the formed loops to the greatest extent.

[0018] As a preferred technical solution:

[0019] As described above, in the spinning method of a boucle composite yarn, both the core yarn and the binding yarn are polyester filaments, with the core yarn having a specification of 50-70D and the binding yarn having a specification of 25-50D; the decorative yarn is wool fiber, which is obtained by stretching wool fiber roving with a basis weight of 4-8g / 10m by 8-10 times.

[0020] In the spinning method of the lobed composite yarn described above, l is 0.15-0.2m and d is 0.02-0.03m.

[0021] As described above, in the spinning method of boucle composite yarn, the rotation speed v1 of the hollow spindle is 600-1500 r / min. The rotation speed of the hollow spindle needs to be kept at a low level because if the rotation speed of the hollow spindle is too high, in order to ensure a small fixed yarn wrapping twist, the linear speed of the output roller and the linear speed of the front roller will also be increased accordingly, which will cause the loop shape formed during wrapping to be unstable.

[0022] The spinning method for a loop composite yarn as described above includes a thermal bonding device comprising a biaxial screw extruder, a timer, and a controller.

[0023] The two melt outlets of the biaxial screw extruder are each connected to a nozzle through a connecting pipe; the two nozzles are arranged on opposite sides of the yarn running path; each connecting pipe is equipped with a pressure boosting valve, a flow regulating valve and a solenoid valve; a timer is used to keep track of the time and send the duration data to the controller, which is used to intermittently send electrical signals to all the solenoid valves, thereby causing the nozzles to intermittently spray melt onto the yarn.

[0024] In the spinning method of the boucle composite yarn described above, the bundling device is located directly below the hollow spindle and directly above the area between the two nozzles; the vertical distance between the bundling device and the nozzles is 3-5 mm.

[0025] In the spinning method of the above-mentioned loop composite yarn, the cooling device used is either an air-cooled cooling device or a water-cooled cooling device. The purpose of cooling is to solidify the bonding points firmly.

[0026] The present invention also provides a loop composite yarn, which is prepared by the spinning method of a loop composite yarn as described in any of the preceding claims;

[0027] Loop composite yarn includes core yarn, decorative yarn and fixing yarn. The decorative yarn forms loops. The theoretical circumference of the loop is L, L=(r-1) / T. The actual circumference of the loop is 0.95-1.10 times L.

[0028] The boucle composite yarn has equally spaced fastening points; along the length of the boucle composite yarn, the fastening points and boucles alternate and are spaced apart by a distance of S, where S=1 / T; at the fastening points, the core yarn, decorative yarn and fastening yarn are bonded together.

[0029] In terms of overall structural morphology, the loop composite yarn of the present invention has not only fixed points, but also significantly increased loop diameter.

[0030] As a preferred technical solution:

[0031] The diameter of the fixed point of the boucle composite yarn described above is 0.2-0.5 mm.

[0032] Beneficial effects:

[0033] (1) The spinning method of the present invention combines the hollow spindle fancy twisting process with the thermal bonding process. At the bonding point, the loop yarn through the hollow spindle is thermally bonded so that the loop formed by the decorative yarn is tightly bonded to the core yarn. Since the bonding is carried out by thermal bonding, the decorative yarn and the core yarn are tightly bonded and not easy to slip off. The overall structural stability of the yarn is better, so a loop yarn with a larger diameter and stable structure can be formed.

[0034] (2) The equivalent diameter of the loops in the boucle composite yarn of the present invention is 4.7-5.3mm, which overcomes the difficulty of spinning large boucle yarn in the prior art, expands the range of boucle yarn types, and improves the application range of boucle yarn. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the loop-composite yarn of the present invention;

[0036] Figure 2 This is a schematic diagram of the spinning apparatus used in the spinning method of the present invention.

[0037] Figure 3 This is a schematic diagram of the thermal bonding device in the spinning apparatus used in the spinning method of the present invention.

[0038] Figure 4 This is a schematic diagram of the combined structure of the bundling device and the thermal bonding device in the spinning apparatus used in the spinning method of the present invention.

[0039] In the diagram, 1-core yarn; 2-loop; 3-fixed yarn; 4-decorative yarn; 5-fixed point; 6-hollow spindle fancy twisting machine; 7-bundling device; 8-thermal fixing device; 81-bidirectional screw extruder; 82-pressure booster valve; 83-flow regulating valve; 84-solenoid valve; 85-controller; 86-timer; 87-nozzle; 88-connecting pipe; 9-cooling device; 10-winding device. Detailed Implementation

[0040] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0041] The following are the relevant performance testing methods for each embodiment and comparative example:

[0042] (1) Structural stability of loops: The loop composite yarn was photographed using the image method, and the average number of decorative yarn short fibers forming complete loops was counted. The unit is roots / loop. The more decorative yarn short fibers forming complete loops, the better the structural stability and the less likely the decorative yarn is to slip off.

[0043] (2) The equivalent diameter of the circle = the actual circumference of the circle / 3.14.

[0044] Example 1A

[0045] A spinning device, such as Figure 2 As shown, it consists of a hollow spindle fancy twisting machine 6, a bundling device 7, a heat-bonding device 8, a cooling device 9, and a winding device 10;

[0046] The height l of the hollow spindle in the hollow spindle fancy twisting machine 6 is 0.15m;

[0047] like Figure 3 As shown, the thermal consolidation device 8 consists of a bidirectional screw extruder 81, two pressure boosting valves 82, two flow regulating valves 83, two solenoid valves 84, a controller 85, a timer 86, two nozzles 87, and two connecting pipes 88.

[0048] The two melt outlets of the biaxial screw extruder 81 are each connected to a nozzle 87 via a connecting pipe 88; the two nozzles 87 are arranged on opposite sides of the yarn running path; each connecting pipe 88 is equipped with a pressure boosting valve 82, a flow regulating valve 83, and a solenoid valve 84; a timer 86 is used for timing and sending the duration data to a controller 85, which is used to intermittently send electrical signals to all solenoid valves 84, thereby causing the nozzles 87 to intermittently spray melt onto the yarn;

[0049] The vertical distance d between the hollow spindle and the nozzle 87 is 20mm;

[0050] The clustering device 7 is located directly below the hollow ingot; simultaneously, the clustering device 7 is located directly above the area between the two nozzles 87, as shown below. Figure 4 As shown; the vertical distance between the clustering device 7 and the nozzle 87 is 3mm;

[0051] Cooling device 9 is an air-cooled cooling device.

[0052] Example 1B

[0053] A method for spinning boucle composite yarn, using the spinning apparatus provided in Example 1A, comprises the following steps:

[0054] (1) Prepare raw materials;

[0055] Core yarn: Polyester filament, specification 50D;

[0056] Decorative yarn: wool fiber, fiber length 60mm, obtained by stretching wool fiber roving with a basis weight of 4g / 10m by 8 times;

[0057] Yarn: Polyester filament, specification 25D;

[0058] Nylon 66 chips: Manufacturer is Shenma Industrial Co., Ltd., grade EPR32;

[0059] (2) Twisting;

[0060] The core yarn, the fixed yarn, and the decorative yarn fed in by the front roller are combined at the top of the hollow spindle of the hollow spindle fancy twisting machine, and then drawn out from the bottom of the hollow spindle by the output roller.

[0061] The fixed yarn wrapping twist T is 300 twists / m, and the decorative yarn overfeed ratio r is 6;

[0062] The rotational speed v1 of the hollow spindle is 1500 r / min, and the linear speed v2 of the output roller is 5 m / min;

[0063] (3) Cluster;

[0064] (4) Thermal consolidation;

[0065] After drying, nylon 66 chips are fed into a biaxial screw extruder. After being heated and melted, they are transported to the nozzle through a connecting pipe equipped with a pressure boosting valve, a flow regulating valve, and a solenoid valve. A timer and a controller control the solenoid valve and the nozzle to intermittently spray the melt onto the yarn, thermally solidifying the knots after the yarn is wrapped. The melt penetrates into the yarn, stably connecting the core yarn and the decorative yarn.

[0066] The interval between the first melt injection and the start of spinning is t1 = (l + d) / v2 = 2.04 s;

[0067] The interval between two consecutive molten injections is t = 1 / (T × v2) = 0.04 s;

[0068] (5) Cooling;

[0069] (6) Winding, to obtain loop composite yarn.

[0070] like Figure 1As shown, the final boucle composite yarn consists of core yarn 1, decorative yarn 4, and fixing yarn 3. Decorative yarn 4 forms boucles 2, with a theoretical circumference of L=(r-1) / T=16.7mm; the actual circumference of boucle 2 is 0.95 times L; the equivalent diameter of boucle 2 is 5.1mm; the boucle composite yarn has evenly spaced fixing points 5, with a diameter of 0.5mm; along the length of the boucle composite yarn, fixing points 5 and boucles 2 alternate and are spaced apart at intervals of S=1 / T=3.3mm; at fixing points 5, core yarn 1, decorative yarn 4, and fixing yarn 3 are bonded together; the average number of decorative yarn short fibers forming a complete boucle is 84 fibers / boucle, the boucle structure is stable, and the decorative yarn is not easy to slip off.

[0071] Comparative Example 1

[0072] A method for spinning composite yarn differs from Example 1B only in that the fiber length of the decorative yarn is 50 mm.

[0073] The final composite yarn has an actual circumference of 15.8 mm and an equivalent diameter of 5.0 mm. The average number of decorative yarn short fibers forming a complete loop is 63 per loop.

[0074] Compared with Example 1, the actual circumference and equivalent diameter of the loops in Comparative Example 1 did not change significantly. The average number of short fibers of the decorative yarn that form complete loops decreased by 25%. This is because when the fiber length of the decorative yarn is short, when the overfed decorative yarn forms loops with a larger diameter, some fiber ends of the decorative yarn will be exposed outside the yarn body and cannot be wrapped by the filaments. Ultimately, this will result in some decorative yarns forming loops with incomplete shapes, poor structural stability, and easy slippage.

[0075] Comparative Example 2

[0076] A method for spinning composite yarn differs from Example 1B only in that the heat consolidation step (4) is omitted.

[0077] Ultimately, it is impossible to make composite yarn with loops because there is no heat bonding, the overall yarn structure is loose and unstable, and the decorative yarn falls off the yarn body.

[0078] Comparative Example 3

[0079] A method for spinning composite yarn differs from Example 1B only in that the interval t1 between the first melt injection moment and the spinning start moment is 1 / v2, i.e., t1 ≠ (1+d) / v2.

[0080] Ultimately, it is impossible to produce composite yarn with loops because when the interval between the first melt injection and the start of spinning is t1≠(l+d) / v2, the consolidation point will not solidify the decorative yarn with the yarn body during thermal consolidation, thus failing to achieve the effect of thermal consolidation. As a result, the loops cannot be formed, and the decorative yarn falls off the yarn body.

[0081] Comparative Example 4

[0082] A method for spinning composite yarn differs from Example 1B only in that the interval between two adjacent melt injection times is t = 0.08s, i.e., t ≠ 1 / (T × v2).

[0083] The final composite yarn has an actual circumference of 31.5 mm and an equivalent diameter of 10.0 mm. The average number of decorative yarn short fibers forming a complete loop is 40 per loop.

[0084] Compared with Example 1, the actual circumference and equivalent diameter of the loops in Comparative Example 4 increased by 99.4%, while the average number of short decorative yarn fibers forming complete loops decreased by 52.4%. This is because when the interval between two adjacent melt spraying times becomes longer, the number of fixation points decreases, and the actual circumference and equivalent diameter of the loops increase. However, due to the decrease in the number of fixation points, the stability of the loop structure decreases, the decorative yarn is prone to slippage, and the loop structure is damaged.

[0085] Example 2A

[0086] A spinning apparatus, differing from Embodiment 1A only in that:

[0087] The height l of the hollow spindle in the hollow spindle fancy twisting machine is 0.16m;

[0088] The vertical distance d between the hollow spindle and the nozzle is 0.025m;

[0089] The cooling device is a water-cooled cooling device.

[0090] Example 2B

[0091] A method for spinning boucle composite yarn, using the spinning apparatus provided in Example 2A, comprises the following steps:

[0092] (1) Prepare raw materials;

[0093] Core yarn: Polyester filament, specification 55D;

[0094] Decorative yarn: wool fiber with a fiber length of 85mm, obtained by stretching wool fiber roving with a basis weight of 6g / 10m by 8.5 times;

[0095] Yarn: Polyester filament, specification 30D;

[0096] Nylon 66 chips: Manufacturer is Shenma Industrial Co., Ltd., grade EPR32;

[0097] (2) Twisting;

[0098] The core yarn, the fixed yarn, and the decorative yarn fed in by the front roller are combined at the top of the hollow spindle of the hollow spindle fancy twisting machine, and then drawn out from the bottom of the hollow spindle by the output roller.

[0099] The fixed yarn wrapping twist T is 280 twists / m, and the decorative yarn overfeed ratio r is 5.5;

[0100] The rotational speed v1 of the hollow spindle is 1260 r / min, and the linear speed v2 of the output roller is 4.5 m / min;

[0101] (3) Cluster;

[0102] (4) Thermal consolidation;

[0103] After drying, nylon 66 chips are fed into a biaxial screw extruder. After being heated and melted, they are transported to the nozzle through a connecting pipe equipped with a pressure boosting valve, a flow regulating valve, and a solenoid valve. A timer and a controller control the solenoid valve and the nozzle to intermittently spray the melt onto the yarn, thermally solidifying the knots after the yarn is wrapped. The melt penetrates into the yarn, stably connecting the core yarn and the decorative yarn.

[0104] The interval between the first melt injection and the start of spinning is t1 = (l + d) / v2 = 2.47 s;

[0105] The interval between two consecutive molten injections is t = 1 / (T × v2) = 0.048 s;

[0106] (5) Cooling;

[0107] (6) Winding, to obtain loop composite yarn.

[0108] like Figure 1 As shown, the final boucle composite yarn consists of core yarn 1, decorative yarn 4, and fixing yarn 3. Decorative yarn 4 forms boucles 2, with a theoretical circumference L = (r-1) / T = 16.1 mm. The actual circumference of boucle 2 is 1.00 times L. The equivalent diameter of boucle 2 is 5.1 mm. The boucle composite yarn has evenly spaced fixing points 5, with a diameter of 0.4 mm. Along the length of the boucle composite yarn, fixing points 5 and boucles 2 alternate and are spaced apart by a spacing S = 1 / T = 3.6 mm. At fixing points 5, core yarn 1, decorative yarn 4, and fixing yarn 3 are bonded together. The average number of decorative yarn short fibers forming a complete boucle is 115 fibers per boucle. The boucle structure is stable, and the decorative yarn is not easy to slip off.

[0109] Example 3A

[0110] A spinning apparatus, differing from Embodiment 1A only in that:

[0111] The height l of the hollow spindle in the hollow spindle fancy twisting machine is 0.18m;

[0112] The vertical distance d between the hollow spindle and the nozzle is 0.028m;

[0113] The vertical distance between the clustering device and the nozzle is 4mm.

[0114] Example 3B

[0115] A method for spinning loop-composite yarn, using the spinning apparatus provided in Example 3A, comprises the following steps:

[0116] (1) Prepare raw materials;

[0117] Core yarn: Polyester filament, specification 60D;

[0118] Decorative yarn: wool fiber with a fiber length of 100 mm, obtained by stretching wool fiber roving with a basis weight of 7 g / 10 m by 9 times;

[0119] Yarn: Polyester filament, specification 35D;

[0120] Nylon 66 chips: Manufacturer is Shenma Industrial Co., Ltd., grade EPR32;

[0121] (2) Twisting;

[0122] The core yarn, the fixed yarn, and the decorative yarn fed in by the front roller are combined at the top of the hollow spindle of the hollow spindle fancy twisting machine, and then drawn out from the bottom of the hollow spindle by the output roller.

[0123] The fixed yarn wrapping twist T is 250 twists / m, and the decorative yarn overfeed ratio r is 4.5;

[0124] The rotational speed v1 of the hollow spindle is 1000 r / min, and the linear speed v2 of the output roller is 4 m / min;

[0125] (3) Cluster;

[0126] (4) Thermal consolidation;

[0127] After drying, nylon 66 chips are fed into a biaxial screw extruder. After being heated and melted, they are transported to the nozzle through a connecting pipe equipped with a pressure boosting valve, a flow regulating valve, and a solenoid valve. A timer and a controller control the solenoid valve and the nozzle to intermittently spray the melt onto the yarn, thermally solidifying the knots after the yarn is wrapped. The melt penetrates into the yarn, stably connecting the core yarn and the decorative yarn.

[0128] The interval between the first melt injection and the start of spinning is t1 = (l + d) / v2 = 3.12 s;

[0129] The interval between two consecutive molten injections is t = 1 / (T × v2) = 0.060 s;

[0130] (5) Cooling;

[0131] (6) Winding, to obtain loop composite yarn.

[0132] like Figure 1 As shown, the final boucle composite yarn consists of core yarn 1, decorative yarn 4, and fixing yarn 3. Decorative yarn 4 forms boucles 2, with a theoretical circumference L = (r-1) / T = 14.0 mm. The actual circumference of boucle 2 is 1.05 times L. The equivalent diameter of boucle 2 is 4.7 mm. The boucle composite yarn has evenly spaced fixing points 5, with a diameter of 0.3 mm. Along the length of the boucle composite yarn, fixing points 5 and boucles 2 alternate and are spaced apart by a distance S = 1 / T = 4.0 mm. At fixing points 5, core yarn 1, decorative yarn 4, and fixing yarn 3 are bonded together. The average number of decorative yarn short fibers forming a complete boucle is 126 fibers per boucle. The boucle structure is stable, and the decorative yarn is not easy to slip off.

[0133] Example 4A

[0134] A spinning apparatus, differing from Embodiment 1A only in that:

[0135] The height l of the hollow spindle in the hollow spindle fancy twisting machine is 0.2m;

[0136] The vertical distance d between the hollow spindle and the nozzle is 0.03m;

[0137] The vertical distance between the clustering device and the nozzle is 5mm;

[0138] The cooling device is a water-cooled cooling device.

[0139] Example 4B

[0140] A method for spinning loop-composite yarn, using the spinning apparatus provided in Example 4A, comprises the following steps:

[0141] (1) Prepare raw materials;

[0142] Core yarn: Polyester filament, specification 70D;

[0143] Decorative yarn: wool fiber, fiber length 120mm, obtained by stretching wool fiber roving with a basis weight of 8g / 10m by 10 times;

[0144] Yarn: Polyester filament, specification 50D;

[0145] Nylon 66 chips: Manufacturer is Shenma Industrial Co., Ltd., grade EPR32;

[0146] (2) Twisting;

[0147] The core yarn, the fixed yarn, and the decorative yarn fed in by the front roller are combined at the top of the hollow spindle of the hollow spindle fancy twisting machine, and then drawn out from the bottom of the hollow spindle by the output roller.

[0148] The fixed yarn wrapping twist T is 200 twists / m, and the decorative yarn overfeed ratio r is 4;

[0149] The rotational speed v1 of the hollow spindle is 600 r / min, and the linear speed v2 of the output roller is 3 m / min;

[0150] (3) Cluster;

[0151] (4) Thermal consolidation;

[0152] After drying, nylon 66 chips are fed into a biaxial screw extruder. After being heated and melted, they are transported to the nozzle through a connecting pipe equipped with a pressure boosting valve, a flow regulating valve, and a solenoid valve. A timer and a controller control the solenoid valve and the nozzle to intermittently spray the melt onto the yarn, thermally solidifying the knots after the yarn is wrapped. The melt penetrates into the yarn, stably connecting the core yarn and the decorative yarn.

[0153] The interval between the first melt injection and the start of spinning is t1 = (l + d) / v2 = 4.6 s;

[0154] The interval between two consecutive molten injections is t = 1 / (T × v2) = 0.1 s;

[0155] (5) Cooling;

[0156] (6) Winding, to obtain loop composite yarn.

[0157] like Figure 1 As shown, the final boucle composite yarn consists of core yarn 1, decorative yarn 4, and fixing yarn 3. Decorative yarn 4 forms boucles 2, with a theoretical circumference of L = (r-1) / T = 15 mm. The actual circumference of boucle 2 is 1.1 times L. The equivalent diameter of boucle 2 is 5.3 mm. The boucle composite yarn has evenly spaced fixing points 5, with a diameter of 0.2 mm. Along the length of the boucle composite yarn, fixing points 5 and boucles 2 alternate and are spaced apart by a distance S = 1 / T = 5 mm. At fixing points 5, core yarn 1, decorative yarn 4, and fixing yarn 3 are bonded together. The average number of decorative yarn short fibers forming a complete boucle is 130 fibers per boucle. The boucle structure is stable, and the decorative yarn is not easy to slip off.

Claims

1. A method for spinning boucle composite yarn, characterized in that, After the core yarn, the fixing yarn, and the decorative yarn fed by the front roller are combined at the top of the hollow spindle, they are drawn out from the bottom of the hollow spindle by the output roller and successively pass through bundling, heat consolidation, cooling, and winding to obtain the loop composite yarn. Among them, the fiber length of the decorative yarn is 60-120mm, the twist of the fixed yarn wrapping T is 200-300 twists / m, and the overfeed ratio of the decorative yarn r is 4-6; During thermal consolidation, the nozzles in the thermal consolidation device intermittently spray melt onto the yarn; The interval between the first injection of melt and the start of spinning is t1, where t1 = (l + d) / v2, l is the height of the hollow spindle in meters, d is the vertical distance between the hollow spindle and the nozzle in meters, and v2 is the linear velocity of the output roller, which is 3-5 m / min. The interval between two consecutive injections of melt is t, where t = 1 / (T × v2).

2. The spinning method of a loop-composite yarn according to claim 1, characterized in that, Both the core yarn and the binding yarn are made of polyester filament. The core yarn has a specification of 50-70D, and the binding yarn has a specification of 25-50D. The decorative yarn is made of wool fiber, which is obtained by stretching wool fiber roving with a basis weight of 4-8g / 10m by 8-10 times.

3. The spinning method of a loop-composite yarn according to claim 1, characterized in that, l is 0.15-0.2m, and d is 0.02-0.03m.

4. The spinning method of a loop-composite yarn according to claim 1, characterized in that, The rotational speed v1 of the hollow spindle is 600-1500 r / min.

5. The spinning method of a loop-composite yarn according to claim 1, characterized in that, The thermal consolidation apparatus includes a biaxial screw extruder, a timer, and a controller; The two melt outlets of the biaxial screw extruder are each connected to a nozzle through a connecting pipe; the two nozzles are arranged on opposite sides of the yarn running path; each connecting pipe is equipped with a pressure boosting valve, a flow regulating valve and a solenoid valve; a timer is used to keep track of the time and send the duration data to the controller, which is used to intermittently send electrical signals to all the solenoid valves, thereby causing the nozzles to intermittently spray melt onto the yarn.

6. The spinning method of a loop-composite yarn according to claim 5, characterized in that, The clustering device is located directly below the hollow ingot and directly above the area between the two nozzles; the vertical distance between the clustering device and the nozzles is 3-5mm.

7. The spinning method of a loop-composite yarn according to claim 1, characterized in that, The cooling system uses either an air-cooled or a water-cooled cooling system.

8. A boucle composite yarn, characterized in that, It is prepared by the spinning method of any one of claims 1-7; Loop composite yarn includes core yarn, decorative yarn and fixing yarn. The decorative yarn forms loops. The theoretical circumference of the loop is L, L=(r-1) / T. The actual circumference of the loop is 0.95-1.10 times L. The boucle composite yarn has equally spaced fastening points; along the length of the boucle composite yarn, the fastening points and boucles alternate and are spaced apart by a distance of S, where S=1 / T; at the fastening points, the core yarn, decorative yarn and fastening yarn are bonded together.

9. A boucle composite yarn according to claim 8, characterized in that, The diameter of the consolidation point is 0.2-0.5 mm.

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