A method for preparing snowflake-shaped bamboo joint fibers

Abstract

This invention belongs to the field of textile material preparation technology, and relates to a method for preparing snowflake-shaped slub filaments. Filament bundles A and B are simultaneously fed into a main networker for twisting, and then wound by a winding device via a third guide roller. Before entering the main networker, filament bundle A sequentially passes through a pre-networker A, a first guide roller A section, a first hot roller A section, a second hot roller A section, a third hot roller, a fourth hot roller, a second oiling device, and a second guide roller. Before entering the main networker, filament bundle B sequentially passes through a first oiling device, a pre-networker B, a first guide roller B section, a first hot roller B section, a second hot roller B section, a third hot roller, a fourth hot roller, a second oiling device, and a second guide roller. This invention, through a differentiated stretching process for the two filament bundles and an innovative hot roller structure, enables filament bundles A and B to form distinct slub structures, resulting in a unique snowflake-like granular effect after twisting.

Description

Technical Field

[0001] This invention belongs to the field of textile material preparation technology, and relates to a method for preparing snowflake-shaped bamboo-joint filaments. Background Technology

[0002] In the field of textile materials, slub fiber, as a functional fiber with a unique alternating thick and thin structure, has expanded its applications from traditional clothing fabrics to high-end decorative and functional textiles. Currently, existing slub fiber preparation technologies mainly achieve this through monofilament stretching, false twisting, or multifilament plying processes.

[0003] As the consumer market upgrades its demand for "natural aesthetics" and "functional versatility" in textiles, many fields have put forward higher requirements for the structural design of bamboo fiber.

[0004] For example, in high-end fashion, consumers are increasingly seeking natural, random textures. Fabrics such as linen and chiffon often simulate natural textures through irregular, uneven structures. However, existing slub yarns, due to their limited form, cannot achieve this natural visual effect through fiber structure. For instance, the pitch of conventional ring-spun slub yarn is typically in a small cycle of five slubs, making it difficult to break free from the constraints of "periodicity." While fully digital equipment can adjust parameters, it still requires a preset program to generate the slubs, failing to achieve a completely random particle distribution. This results in a rigid fabric texture that fails to meet designers' requirements for "natural randomness."

[0005] In the high-end home textiles sector, consumers have significantly increased their demands for three-dimensional layering and decorative effects. Granular yarns can enhance the visual depth of fabrics through light reflection and shadow variations, but the uniform distribution of traditional slub yarns makes it difficult to achieve this dynamic visual experience. Summary of the Invention

[0006] The purpose of this invention is to solve the problems of monotonous texture and insufficient three-dimensional layering in the application of bamboo-joint fibers in various fields in the prior art, and to provide a method for preparing snowflake-shaped bamboo-joint fibers.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing snowflake-shaped bamboo joint filaments (i.e. bamboo joint filaments with random thickness distribution and granular bamboo joint drawing filaments) involves feeding filament bundle A and filament bundle B into a main networker for stranding, and then winding them by a winding device via a third guide roller.

[0009] Before being fed into the main networker, the filament bundle A passes through the pre-networker A, the first guide roller A section, the first hot roller A section, the second hot roller A section, the third hot roller, the fourth hot roller, the second oiling device, and the second guide roller in sequence.

[0010] Before being fed into the main networker, the filament bundle B passes through the first oiling device, the pre-networker B, the first guide roller section B, the first hot roller section B, the second hot roller section B, the third hot roller, the fourth hot roller, the second oiling device, and the second guide roller in sequence.

[0011] The first guide roller, section A and section B, are two length segments of the first guide roller. Both are cylindrical and coaxial. The diameter of section B is 1.1-1.2 times the diameter of section A. Specifically, the diameter of section A is 91.67-100 mm, and the diameter of section B is 110 mm. The surface roughness of the first guide roller is uniform, ranging from 1.3 to 1.5 μm.

[0012] The first hot roller section A and the first hot roller section B are two length segments of the first hot roller. Both are cylindrical structures and coaxial. The diameter of the first hot roller section B is 1.1-1.2 times the diameter of the first hot roller section A. Specifically, the diameter of the first hot roller section A is 183.33-200 mm, and the diameter of the first hot roller section B is 220 mm. The circumferential surface of the first hot roller is divided into two parts symmetrically distributed along the central axis of the first hot roller. The roughness of one part is 0.1-0.15 μm, and the roughness of the other part is 1.3-1.5 μm.

[0013] The second hot roller, section A and section B, are two length segments of the second hot roller. Both are cylindrical and coaxial. The diameter of section B is 1.1-1.2 times that of section A. Specifically, the diameter of section A is 183.33-200 mm, and the diameter of section B is 220 mm. The circumferential surface of the second hot roller is divided into two symmetrically distributed parts along its central axis. One part has a roughness of 0.1-0.15 μm, and the other part has a roughness of 1.3-1.5 μm.

[0014] The third hot roller has a cylindrical structure and a diameter of 220 mm. The surface roughness of the third hot roller is uniform, ranging from 0.30 to 0.35 μm.

[0015] The fourth hot roller has a cylindrical structure and a diameter of 220 mm. The surface roughness of the fourth hot roller is uniform, ranging from 0.30 to 0.35 μm.

[0016] Both filament bundle A and filament bundle B have 0.5 turns of winding on the first to fourth hot rollers;

[0017] Both the second and third guide rollers are cylindrical structures with a diameter of 110 mm and uniform surface roughness ranging from 1.3 to 1.5 μm.

[0018] This invention utilizes a differentiated stretching process with dual filament bundles and innovative hot roller structure to create distinct bamboo-like structures in filament bundles A and B, resulting in a unique "snowflake-like" effect after twisting. The first guide roller, first hot roller, and second hot roller all employ a dual-diameter segmented structure. Segments A and B on the same roller are coaxial and rotate at the same speed, with segment B having a larger diameter than segment A, resulting in a significantly higher linear velocity in segment B. The path for filament bundle A is: pre-networker A → first guide roller segment A → first hot roller segment A → second hot roller segment A. The path for filament bundle B is: pre-networker B → first guide roller segment B → first hot roller segment B → second hot roller segment B. Due to the lower linear velocity in segment A and the higher linear velocity in segment B, the cumulative stretching ratio of filament bundle A is larger from the first to the fourth hot roller stage, while the cumulative stretching ratio of filament bundle B is smaller. After being initially bundled by pre-networkers A and B, filament bundles A and B are softened by heating with the first and second hot rollers, and then stretched and shaped by the third and fourth hot rollers. Because filament bundle A has a higher stretch ratio, the internode length is significantly extended, while filament bundle B has a lower stretch ratio, maintaining a short internode spacing and granular texture. Simultaneously, the first and second hot rollers employ a dual-roughness design on their circumferential surfaces, creating a random structure within the filament bundles that alternates between fully and insufficiently stretched sections, enhancing the naturalness and diversity of the internode shape. Finally, filament bundle A (long internodes) and filament bundle B (granular internodes) enter the main networker between the second and third guide rollers and are twisted together. Due to the different stretch ratios, the internode length, density, and shape of the two filament bundles differ significantly, resulting in a snowflake-like texture on the fabric surface after twisting, where long internodes and granules intertwine. Before pre-networking, filament B is oiled by the first oiling device. When passing through the hot roller, the heating efficiency decreases. Between the second hot roller section B and the third hot roller, the network nodes are difficult to stretch due to insufficient softening, further enhancing the three-dimensional effect of the granular bamboo joints. After pre-networking, filament A is stretched by the hot roller and then oiled by the second oiling device. Since it is not oiled in advance after pre-networking, the fibers directly contact the hot roller, resulting in higher heating efficiency and more complete stretching, forming a smooth and slender bamboo joint structure.

[0019] The diameter of section B of the first guide roller, the first hot roller, and the second hot roller needs to be controlled to be 1.1-1.2 times the diameter of the corresponding section A. If the diameter of section B is too large, the linear speed of the filament bundle B running in section B will be too high, resulting in a low cumulative draft ratio and excessively stiff granular fibers, affecting the comfort of the fabric. If the diameter of section B is too small, the linear speed of the filament bundle B will be insufficient, resulting in an excessively high cumulative draft ratio, causing the slub joints to be overstretched, making it difficult to maintain the short-pitch granular texture, and ultimately preventing the A and B filament bundles from presenting the ideal snowflake-like texture after being twisted together. The circumferential surface roughness of the first guide roller needs to be maintained at 1.3-1.5μm, while that of the third and fourth hot rollers needs to be controlled at 0.30-0.35μm. If the roughness value is too high, it will reduce the gripping force of the filament bundle on the circumferential surface, causing production problems such as tangling around the roller and inability to pull, while if the value is too low, it will enhance the gripping force, reduce the phenomenon of slippage during drafting, and weaken the randomness of the slub joint effect. For the first and second hot rollers, a dual-roughness design is adopted on their circumferential surfaces. In the area with a roughness of 0.1-0.15μm, if the value is too high, insufficient heating will result in inadequate contact area between the filaments and the hot rollers, leading to defects such as fuzz. If the value is too low, the heating will be too uniform, which is not conducive to forming a bamboo-like effect. In the area with a roughness of 1.3-1.5μm, if the value is too high, the filaments may not be able to be drawn and may break. If the value is too low, it will affect the stretching and slippage effect, ruining the bamboo-like style. The number of turns for filaments A and B on the first to fourth hot rollers is uniformly set to 0.5 turns. This parameter is determined by the equipment structure and process adaptability to ensure that the stretching and shaping process of the filaments on the hot rollers is stable and meets the forming requirements of snowflake-shaped bamboo-like filaments.

[0020] As a preferred technical solution:

[0021] In the method for preparing snowflake-shaped bamboo-joint fibers as described above, the first oiling device is an oil nozzle;

[0022] The air pressure of pre-networker A and pre-networker B is 0.34-0.36MPa. Network points are added before filament bundles A and B enter the first guide roller A section and the first guide roller B section because the filament bundle running speed is relatively slow and the tension is relatively small at this time, and the network points formed under this condition are more solid. In addition, higher air pressure will disrupt the orderly arrangement of macromolecules inside the fiber, resulting in a decrease in orientation and crystallinity, which is beneficial to improving the boiling water shrinkage rate of the fiber.

[0023] The pre-networker A is a vertical plate with a constant cross-section (i.e., the shape and size of its cross-section remain unchanged along the entire length of the vertical plate). It has horizontally arranged airflow nozzles. A certain cross-section of the pre-networker A passes through the airflow nozzle. This cross-section is an Archimedean spiral with a polar angle greater than 360° and less than 450°. The airflow nozzle is located at a position with a polar angle of 180° on the Archimedean spiral and faces the center of the Archimedean spiral.

[0024] The structure and dimensions of pre-networker B are the same as those of pre-networker A;

[0025] The guide hooks at the inlet and outlet of the pre-networker A are grooved guide hooks. The grooved guide hook consists of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle A in the bottom area of ​​the U-shaped guide hook.

[0026] The filament bundle A passes from top to bottom through the bottom area of ​​the upper grooved guide hook, the center of the pre-networker A, and the bottom area of ​​the lower grooved guide hook.

[0027] The guide hooks at the inlet and outlet of the pre-networker B are grooved guide hooks. The grooved guide hook consists of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle B in the bottom area of ​​the U-shaped guide hook.

[0028] The wire bundle B passes from top to bottom through the bottom area of ​​the upper grooved wire guide hook, the center of the pre-networker B, and the bottom area of ​​the lower grooved wire guide hook.

[0029] This invention sets the air pressure of pre-networking device A and pre-networking device B to 0.34-0.36 MPa, which is significantly higher than the pre-networking air pressure of 2.8-3.0 kgf / cm2 (approximately 0.28-0.29 MPa) in patent application CN109594137A. This increases the strength and density of the network nodes, thereby improving the density of the bamboo joints. To avoid problems such as fuzzy fibers, broken fibers, uneven network points, and inability to complete the initial growth due to the increased air pressure of pre-networking device A or pre-networking device B, this invention changes the oiling method in patent application CN109594137A from oil wheel oiling to oil nozzle oiling, replaces the pre-networking device with a pre-networking device having an Archimedean spiral structure, and replaces the U-shaped guide hooks at the front and rear of the pre-networking device with grooved guide hooks.

[0030] The first oiling device of this invention is an oil nozzle. After the filament bundle B enters the filament channel of the oil nozzle, the oil is sprayed out from the oil spray hole of the oil nozzle to oil the filament bundle B. After oiling, the individual filaments of the filament bundle B also have good mutual adhesion and can be bundled. Compared with the patent application with publication number CN109594137A, the bundling distance is reduced.

[0031] This invention employs pre-networkers A and B, each with an Archimedean spiral structure. Their respective inner chambers are relatively enclosed, locking the filament bundle and preventing it from detaching from the central path of the pre-networker. Simultaneously, this structure optimizes the force distribution of the filament bundle upon entering the pre-networker, resulting in better cohesion of the individual filaments within the pre-networker and ensuring the strength and density of the network nodes. Furthermore, the spiral airflow within the pre-networker can be orderly discharged after rotation, maintaining stable internal air pressure, reducing friction between the filament bundle and the edges of the pre-networker, thereby reducing fuzz and breakage, and improving the fiber's breaking strength.

[0032] This invention provides grooved guide hooks at the inlet and outlet of pre-networker A and pre-networker B, respectively. These two grooved guide hooks confine wire bundles A and B to the center of the pre-networker, ensuring a more consistent force distribution on both bundles after they enter pre-networker A and pre-networker B. If conventional U-shaped guide hooks are used, the larger angles of the wire bundles before and after entering the pre-networker can prevent them from being positioned in the center, leading to inconsistent force distribution and uneven network coverage.

[0033] In the method for preparing snowflake-shaped bamboo filaments as described above, the Archimedean spiral coefficient (representing the increase or decrease in the polar diameter per degree of rotation) is 1-2 mm / °, and the polar diameter is 1.5-2 mm when the polar angle is 0°; the airflow nozzle is a circular hole with a diameter of 1.1-1.3 mm, and the airflow nozzle is located in the middle of the pre-networker A in the vertical direction; the length of the pre-networker A in the vertical direction is 23-27 mm.

[0034] In the method for preparing snowflake-shaped bamboo joint filaments as described above, the distance between the guide hooks at the inlet and outlet of the pre-networker A and the pre-networker A is 13-17 mm in the vertical direction; the angle α between the filament bundle A at the upper groove-shaped guide hook and the vertical direction is 5-10°; the angle β between the filament bundle A at the lower groove-shaped guide hook and the vertical direction is 5-10°.

[0035] Along the vertical direction, the distance between the guide hook at the inlet and outlet of the pre-networker B and the pre-networker B is 13-17mm; the angle γ between the wire bundle B at the upper grooved guide hook and the vertical direction is 5-10°; the angle δ between the wire bundle B at the lower grooved guide hook and the vertical direction is 5-10°.

[0036] In the method for preparing snowflake-shaped bamboo filaments as described above, the airflow nozzles of the pre-networker A and pre-networker B at each spinning position are each connected to a branch pipe, and all the branch pipes are connected to the same main pipe, which is equipped with an automatic pressure regulating valve at the air inlet end.

[0037] In the method for preparing snowflake-shaped bamboo-joint filaments as described above, the linear speed of the first guide roller B section is 1690 m / min, the temperature of the first hot roller is 50-55℃, the linear speed of the first hot roller B section is 1700 m / min, the temperature of the second hot roller is 50-55℃, the linear speed of the second hot roller B section is 1800 m / min, the temperature of the third hot roller is 100-105℃, the linear speed of the third hot roller is 3200 m / min, the temperature of the fourth hot roller is 100-105℃, the linear speed of the fourth hot roller is 3200 m / min, the linear speed of the second guide roller is 3220 m / min, the linear speed of the third guide roller is 3250 m / min, and the winding speed of the winding device is 3175-3275 m / min.

[0038] In the method for preparing snowflake-shaped bamboo filaments as described above, the air pressure of the main network device is 0.38-0.42 MPa.

[0039] In the above-described method for preparing snowflake-shaped bamboo-joint filaments, the second oiling device is an integrated oil nozzle; the first oiling device uses crude oil for oiling, with an oiling rate of 0.4-0.5%; the second oiling device uses an oiling agent with a concentration of 19.5-20.5 wt% (the percentage of the mass of the oiling agent to the total mass of the oiling agent and water), with an oiling rate of 0.5-0.6%.

[0040] The method for preparing snowflake-shaped bamboo filaments as described above includes filament bundle A and filament bundle B containing 0.21-0.23 wt% matting agent, and filament bundle A and filament bundle B having a specification of 50-73 dtex / 24f.

[0041] As described in any of the preceding methods, the snowflake-shaped bamboo joint filaments have a strip unevenness rate (CV) of 21.3-26.3% (a performance index reflecting the degree of local thickness unevenness of the snowflake-shaped bamboo joint filaments), a bamboo joint density (i.e., the number of bamboo joints in one meter of snowflake-shaped bamboo joint filaments) of 36-45 / meter, a breaking elongation of 86-88%, a breaking strength of ≥3.2cN / dtex, a boiling water shrinkage rate of 30-35%, a filament degradation rate ≤0.13%, a breakage count ≤8.9 times / 18 positions·24 hours, and a network degree deviation ≤6 units / meter.

[0042] Beneficial effects:

[0043] (1) This invention uses a double-filament differentiated stretching process, combined with the dual-diameter segmented structure of the first guide roller, the first hot roller and the second hot roller, to make the cumulative stretching multiple of filament A large, forming long bamboo joints, while the cumulative stretching multiple of filament B small, maintaining short-pitch granular bamboo joints; after twisting, the bamboo joints of the two filament bundles have significant differences in joint length, density and shape, presenting a snowflake-like texture of long joints and granules interwoven on the fabric surface.

[0044] (2) The first and second hot rollers of the present invention adopt a double roughness design on their peripheral surfaces, so that the inside of the filament bundle produces a random structure with alternating periods of sufficient and insufficient stretching.

[0045] (3) In this invention, the filament bundle B is oiled by the first oiling device before pre-networking. When it passes through the hot roller, the heating efficiency is reduced. The three-dimensional effect of the granular bamboo joint is enhanced under a small stretching ratio between the second hot roller B section and the third hot roller. After pre-networking, the filament bundle A is first stretched by the hot roller and then oiled by the second oiling device. The fibers directly contact the hot roller, resulting in higher heating efficiency and more thorough stretching, forming a smooth and slender bamboo joint structure.

[0046] (4) The present invention sets the air pressure of pre-networker A and pre-networker B to 0.34-0.36MPa (higher than the prior art), and adopts an Archimedes spiral structure pre-networker, with grooved guide hooks to limit the wire bundle in the middle position of the pre-networker, optimize the force distribution of the wire bundle, and increase the strength and density of the network nodes. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the pre-networker A of the present invention;

[0048] Figure 2 In Figure a, it is a schematic diagram of the cross-section of a conventional pre-networker in the prior art, and in Figure b, it is a schematic diagram of the cross-section of the pre-networker A of the present invention. The bold black arrows in the figures represent airflow.

[0049] Figure 3 This is a schematic diagram of the grooved guide wire hook of the present invention;

[0050] Figure 4 This is a schematic diagram showing the travel paths of filament bundles A and B during the preparation of snowflake-shaped bamboo joint filaments according to the present invention.

[0051] Figure 5 and Figure 6 A photograph of a stocking made from snowflake-shaped bamboo filaments from Example 1. Figure 5 and Figure 6 It's the same garter sample. Figure 5 In a stretched state, Figure 6 (in its natural state);

[0052] 1-Fiber bundle A, 2-Fiber bundle B, 3-First guide roller, 3.1-U-shaped guide hook, 3.2-Limiting block, 4-First heating roller, 5-Second heating roller, 6-Third heating roller, 7-Fourth heating roller, 8-Second guide roller, 9-Third guide roller, 10-Main networker, 11-Pre-networker A, 11.1-Airflow nozzle. Detailed Implementation

[0053] 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.

[0054] The following are the test methods for the relevant performance indicators in each embodiment and comparative example:

[0055] Evenness coefficient (CV) value: The sample was tested using a USTER 5 evenness tester in accordance with GB / T 14346-2015 "Test Method for Evenness of Chemical Fiber Filaments - Capacitive Method". The specific procedure was as follows: the sample was first conditioned in an environment with a temperature of 20℃ and a humidity of 65% for 2 hours. Then, the sample was passed through the two plates of a capacitor at a uniform speed. The mass of the sample in each equal interval was converted into an electrical signal. The percentage of the standard deviation of all test electrical signals to the mean value was the evenness coefficient (CV) value. The test speed was 200 m / min and the test time for the sample was 2.5 min.

[0056] Intrinsic viscosity: According to GB / T 14190-2017 "Test Method for Fiber Grade Polyester (PET) Chips", the viscosity was measured using an Ubbelohde viscometer. The sample was dissolved in a mixed solvent of phenol and tetrachloroethane (mass ratio of phenol to tetrachloroethane was 3:2) to prepare a solution with a density of 1.235 g / cm³. 3 The sample solution is tested, and the outflow time of the solution in the Ubbelohde viscometer is measured. The relative viscosity is obtained by the ratio of the outflow time t of the sample solution to the outflow time t0 of the pure solvent. Based on the relative viscosity, the corresponding F factor is found from the F factor table. The intrinsic viscosity is obtained by dividing the F factor by the concentration of the sample solution (concentration of sample solution = sample weight / sample solution volume, where the sample weight is 0.125g and the sample solution volume is 25mL).

[0057] Bamboo node density: The number of bamboo nodes in a snowflake-shaped bamboo filament within one meter, observed by appearance.

[0058] Tensile strength and elongation at break: The tensile properties of chemical fiber filaments were tested using a fully automatic single yarn tensile testing machine (model YG023B-Ⅱ) in accordance with GB / T 14344-2022 "Test Method for Tensile Properties of Chemical Fiber Filaments". The specific process was as follows: the sample was first conditioned in an environment with a temperature of 20℃ and a relative humidity of 65% for 4 hours. Then, it was clamped by upper and lower clamps (clamping length of 500mm), and a pretension of 0.05cN / dtex was applied by a robot arm to stabilize the sample. At the beginning of the test, the lower clamp stretched the sample at a uniform speed of 500mm / min until the sample broke. At the same time, the real-time data of the force sensor was recorded during the stretching process, and the relationship curve between strength and elongation was plotted by the data collection system. Finally, the tensile strength and elongation at break of the sample were obtained through data processing and analysis.

[0059] Boiling water shrinkage rate: Referring to GB / T 6505-2017 "Test Method for Heat Shrinkage Rate of Chemical Fiber Filaments (After Treatment)" standard, the boiling water shrinkage rate of the samples was tested using the twisting method. The samples were treated with boiling water, and the sample length before and after boiling water treatment were measured simultaneously. The boiling water shrinkage rate was calculated using the following formula:

[0060] Boiling water shrinkage rate = (sample length before boiling water treatment - sample length after boiling water treatment) × 100% / sample length before boiling water treatment.

[0061] Downgrading rate of filaments: The downgrading of a silk cake is determined by whether there are more than 2 broken filaments on its surface. If there are more than 2, it is downgraded. The downgrading rate of filaments is then calculated using the following formula: Downgrading rate of filaments = Number of downgraded filaments × 100% / Total number of filaments.

[0062] Number of spindle breaks: Spindle breakage refers to the sudden breakage of a single filament during spinning. One spindle breakage is counted as one breakage. A statistical period of 10 days and 18 spindle positions is used as a statistical period. The number of spindle breaks in 24 hours and 18 spindle positions is calculated based on the average value.

[0063] Network density deviation: Network density deviation = |Measured network density - Standard network density value|. The measured network density is determined according to the standard "Test Method for Network Density of Synthetic Fiber Filaments" (FZ / T 50001-2016). The sample is adjusted to a suitable tension through a pre-tensioning system, and the splitting needle is slowly moved in the filament of a specified length. When the network node hits the splitting needle, the needle stops moving. The number of network nodes calculated at this time is the measured network density. The standard network density value refers to the target reference value of the number of network nodes per unit length (per meter) that is set in advance according to product requirements, industry specifications or enterprise standards.

[0064] Example 1

[0065] A method for preparing snowflake-shaped bamboo joint fibers, the specific steps of which are as follows:

[0066] (1) Prepare fiber bundle A and fiber bundle B;

[0067] The preparation process of filament A is as follows: a matting agent (titanium dioxide) is added to PET melt with an intrinsic viscosity of 0.62 dL / g (PET is obtained by esterification and polycondensation reaction of PTA and EG, and the content of PTA in the reaction raw materials is 69 wt%). After that, it is sprayed out from the spinneret hole (the cross-section is circular) and cooled and shaped to obtain filament A with a specification of 50 dtex / 24f (the content of matting agent in the filament is 0.22 wt%).

[0068] The preparation process of filament bundle B is the same as that of filament bundle A;

[0069] (2) Preparation of snowflake-shaped bamboo strands;

[0070] like Figure 4 As shown, the filament bundle A1 passes sequentially through the pre-networker A, the first guide roller 3A section, the first hot roller 4A section, the second hot roller 5A section, the third hot roller 6, the fourth hot roller 7, the second oiling device, and the second guide roller 8. The filament bundle B2 passes sequentially through the first oiling device, the pre-networker B, the first guide roller 3B section, the first hot roller 4B section, the second hot roller 5B section, the third hot roller 6, the fourth hot roller 7, the second oiling device, and the second guide roller 8. Then, filament bundles A and B are simultaneously fed into the main networker 10 for twisting, and then wound by the winding device through the third guide roller 9 to obtain snowflake-shaped bamboo-joint filaments.

[0071] The air pressure of both pre-networker A and pre-networker B is 0.34 MPa; the structures and dimensions of pre-networkers A and B are exactly the same; for example... Figure 1 and Figure 2 As shown in Figure b, the pre-networker A11 is a vertical plate with a uniform cross-section and horizontally arranged airflow nozzles 11.1. A certain cross-section of the pre-networker A11 passes through the airflow nozzles 11.1. This cross-section is an Archimedean spiral with a polar angle of 360° and an Archimedean spiral coefficient of 1 mm / °. The polar diameter of the Archimedean spiral at a polar angle of 0° is 1.5 mm. The airflow nozzles 11.1 are located at a position on the Archimedean spiral with a polar angle of 180° and face the center of the Archimedean spiral. The airflow nozzles 11.1 are circular holes with a diameter of 1.1 mm and are located in the middle of the pre-networker A11 in the vertical direction. The length of the pre-networker A11 in the vertical direction is 23 mm.

[0072] like Figure 3As shown, the guide hooks at the inlet and outlet of the pre-networker A are grooved guide hooks, which consist of a U-shaped guide hook 3.1 and a limiting block 3.2. The U-shaped guide hook 3.1 is arranged horizontally, and the limiting block 3.2 is connected to the inner wall of the U-shaped guide hook 3.1 to limit the wire bundle A within the bottom area of ​​the U-shaped guide hook 3.1. The wire bundle A passes from top to bottom through the bottom area of ​​the upper grooved guide hook, the center of the pre-networker A, and the bottom area of ​​the lower grooved guide hook. In the vertical direction, the distance between the guide hooks at the inlet and outlet of the pre-networker A and the pre-networker A is 13mm. At the upper grooved guide hook, the angle α between the wire bundle A and the vertical direction is 5°; at the lower grooved guide hook, the angle β between the wire bundle A and the vertical direction is 5°.

[0073] The guide hooks at the inlet and outlet of the pre-networker B are grooved guide hooks, which consist of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle B within the bottom area of ​​the U-shaped guide hook. The wire bundle B passes through the bottom area of ​​the upper grooved guide hook, the center of the pre-networker B, and the bottom area of ​​the lower grooved guide hook from top to bottom. In the vertical direction, the distance between the guide hooks at the inlet and outlet of the pre-networker B and the pre-networker B is 13mm. The angle γ between the wire bundle B and the vertical direction at the upper grooved guide hook is 5°. The angle δ between the wire bundle B and the vertical direction at the lower grooved guide hook is 5°.

[0074] Each of the airflow nozzles of the pre-networker A and pre-networker B at each spinning station is connected to a branch pipe, and all the branch pipes are connected to the same main pipe. An automatic pressure regulating valve is installed on the air inlet end of the main pipe.

[0075] The first guide roller section A and the first guide roller section B are two length segments of the first guide roller. Both are cylindrical structures and coaxial. The diameter of the first guide roller section A is 91.67 mm, and the diameter of the first guide roller section B is 110 mm. The circumferential surface roughness of the first guide roller is uniform and is 1.3 μm.

[0076] The first hot roller section A and the first hot roller section B are two length sections of the first hot roller. Both are cylindrical structures and coaxial. The diameter of the first hot roller section A is 183.33 mm and the diameter of the first hot roller section B is 220 mm. The circumferential surface of the first hot roller is divided into two parts symmetrically distributed along the central axis of the first hot roller. The roughness of one part is 0.1 μm and the roughness of the other part is 1.3 μm.

[0077] The second hot roller section A and the second hot roller section B are two length segments of the second hot roller. Both are cylindrical structures and coaxial. The diameter of the second hot roller section A is 183.33 mm, and the diameter of the second hot roller section B is 220 mm. The circumferential surface of the second hot roller is divided into two parts symmetrically distributed along the central axis of the second hot roller. The roughness of one part is 0.1 μm, and the roughness of the other part is 1.3 μm.

[0078] The third hot roller has a cylindrical structure and a diameter of 220 mm. The surface roughness of the third hot roller is uniform and is 0.3 μm.

[0079] The fourth hot roller has a cylindrical structure and a diameter of 220 mm. The surface roughness of the fourth hot roller is uniform and is 0.3 μm.

[0080] Both filament bundle A and filament bundle B have 0.5 turns of winding on the first to fourth hot rollers;

[0081] Both the second and third guide rollers are cylindrical structures with a diameter of 110 mm and a uniform circumferential surface roughness of 1.3 μm.

[0082] The second oiling device is an integrated oil nozzle, while the first oiling device is an oil nozzle. The first oiling device uses crude oil for oiling, with an oiling rate of 0.4%. The second oiling device uses an oil agent with a concentration of 19.5 wt%, with an oiling rate of 0.5%. The linear speed of the first guide roller section B is 1690 m / min, the temperature of the first hot roller is 50℃, the linear speed of the first hot roller section B is 1700 m / min, the temperature of the second hot roller is 50℃, the linear speed of the second hot roller section B is 1800 m / min, the temperature of the third hot roller is 100℃, the linear speed of the third hot roller is 3200 m / min, the temperature of the fourth hot roller is 100℃, the linear speed of the fourth hot roller is 3200 m / min, the linear speed of the second guide roller is 3220 m / min, the air pressure of the main network device is 0.38 MPa, the linear speed of the third guide roller is 3250 m / min, and the winding speed of the winding device is 3175 m / min.

[0083] The final snowflake-shaped bamboo filaments had a strip unevenness CV value of 23.9%, a bamboo node density of 40 nodes / meter, a breaking elongation of 86.3%, a breaking strength of 3.48 cN / dtex, a boiling water shrinkage rate of 33.6%, a filament downgrading rate of 0.05%, a breakage count of 7.3 times / 18 positions·24 hours, and a network density deviation of 3 nodes / meter (the standard value for network density is 22 nodes / meter).

[0084] The actual product of the snowflake-shaped bamboo-joint filament woven from the garter belts produced in this embodiment is shown below. Figure 5 and Figure 6 As shown, from Figure 6As can be seen, the surface of the garter belt in its natural state exhibits a snowflake-like texture with interwoven segments and granules. The distribution of the segments lacks obvious periodicity, consistent with the visual effect of "snowflake-like granules." Figure 5 As can be seen, under tension, the long bamboo segments of the garter belt are stretched and maintain their continuous shape, while the granular bamboo segments retain their short-segment protrusion. The difference between the two bamboo segment structures becomes more significant, further highlighting the layered texture of the snowflake-like pattern. The overall texture of the garter belt is natural and random, without rigid periodic repetition, confirming the effect of the differentiated stretching of the dual filament bundles and the dual roughness design of the hot rollers on enhancing the diversity of bamboo segment shapes.

[0085] Example 2

[0086] A method for preparing snowflake-shaped bamboo joint fibers, the specific steps of which are as follows:

[0087] (1) Prepare fiber bundle A and fiber bundle B;

[0088] The preparation process of filament A is as follows: a matting agent (titanium dioxide) is added to PET melt with an intrinsic viscosity of 0.628 dL / g (PET is obtained by esterification and polycondensation reaction of PTA and EG, and the content of PTA in the reaction raw materials is 70.5 wt%), and then it is sprayed out from the spinneret hole (circular cross-section) of the spinneret. After cooling and shaping, filament A with a specification of 59 dtex / 24f (the content of matting agent in the filament is 0.21 wt%) is obtained.

[0089] The preparation process of filament bundle B is the same as that of filament bundle A;

[0090] (2) Preparation of snowflake-shaped bamboo strands;

[0091] Fiber bundle A is sequentially passed through pre-networker A, first guide roller A section, first hot roller A section, second hot roller A section, third hot roller, fourth hot roller, second oiling device and second guide roller. Fiber bundle B is sequentially passed through first oiling device, pre-networker B, first guide roller B section, first hot roller B section, second hot roller B section, third hot roller, fourth hot roller, second oiling device and second guide roller. Fiber bundles A and B are then simultaneously fed into the main networker for stranding, and then wound by the winding device via the third guide roller to obtain snowflake-shaped bamboo-joint filaments.

[0092] Both pre-networker A and pre-networker B have an air pressure of 0.34 MPa. Pre-networker A and pre-networker B have identical structures and dimensions. Pre-networker A is a vertical plate with a uniform cross-section and horizontally arranged airflow nozzles. A certain cross-section of pre-networker A passes through these nozzles; this cross-section is an Archimedean spiral with a polar angle of 450°, an Archimedean helix coefficient of 2 mm / °, and a polar diameter of 2 mm when the polar angle is 0°. The airflow nozzles are located at a position on the Archimedean spiral with a polar angle of 180°, facing the center of the Archimedean spiral. The airflow nozzles are circular orifices with a diameter of 1.3 mm, located vertically in the middle of pre-networker A. The length of pre-networker A is 25 mm vertically.

[0093] The guide hooks at the inlet and outlet of the pre-networker A are grooved guide hooks, which consist of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle A within the bottom area of ​​the U-shaped guide hook. The wire bundle A passes through the bottom area of ​​the upper grooved guide hook, the center of the pre-networker A, and the bottom area of ​​the lower grooved guide hook from top to bottom. In the vertical direction, the distance between the guide hooks at the inlet and outlet of the pre-networker A and the pre-networker A is 15mm. The angle α between the wire bundle A and the vertical direction at the upper grooved guide hook is 8°. The angle β between the wire bundle A and the vertical direction at the lower grooved guide hook is 8°.

[0094] The guide hooks at the inlet and outlet of the pre-networker B are grooved guide hooks, which consist of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle B within the bottom area of ​​the U-shaped guide hook. The wire bundle B passes from top to bottom through the bottom area of ​​the upper grooved guide hook, the center of the pre-networker B, and the bottom area of ​​the lower grooved guide hook. In the vertical direction, the distance between the guide hooks at the inlet and outlet of the pre-networker B and the pre-networker B is 15mm. The angle γ between the wire bundle B and the vertical direction at the upper grooved guide hook is 8°. The angle δ between the wire bundle B and the vertical direction at the lower grooved guide hook is 8°.

[0095] Each of the airflow nozzles of the pre-networker A and pre-networker B at each spinning station is connected to a branch pipe, and all the branch pipes are connected to the same main pipe. An automatic pressure regulating valve is installed on the air inlet end of the main pipe.

[0096] The first guide roller section A and the first guide roller section B are two length segments of the first guide roller. Both are cylindrical structures and coaxial. The diameter of the first guide roller section A is 94 mm and the diameter of the first guide roller section B is 110 mm. The circumferential surface roughness of the first guide roller is uniform and is set to 1.4 μm.

[0097] The first hot roller section A and the first hot roller section B are two length sections of the first hot roller. Both are cylindrical structures and coaxial. The diameter of the first hot roller section A is 190 mm and the diameter of the first hot roller section B is 220 mm. The circumferential surface of the first hot roller is divided into two parts symmetrically distributed along the central axis of the first hot roller. The roughness of one part is 0.13 μm and the roughness of the other part is 1.4 μm.

[0098] The second hot roller section A and the second hot roller section B are two length sections of the second hot roller. Both are cylindrical structures and coaxial. The diameter of the second hot roller section A is 190 mm and the diameter of the second hot roller section B is 220 mm. The circumferential surface of the second hot roller is divided into two parts symmetrically distributed along the central axis of the second hot roller. The roughness of one part is 0.13 μm and the roughness of the other part is 1.4 μm.

[0099] The third hot roller has a cylindrical structure and a diameter of 220 mm. The surface roughness of the third hot roller is uniform and is 0.33 μm.

[0100] The fourth hot roller has a cylindrical structure and a diameter of 220 mm. The surface roughness of the fourth hot roller is uniform and is 0.33 μm.

[0101] Both filament bundle A and filament bundle B have 0.5 turns of winding on the first to fourth hot rollers;

[0102] Both the second and third guide rollers are cylindrical structures with a diameter of 110 mm and a uniform circumferential surface roughness of 1.4 μm.

[0103] The second oiling device is an integrated oil nozzle, while the first oiling device is an oil nozzle. The first oiling device uses crude oil for oiling, with an oiling rate of 0.45%. The second oiling device uses an oil agent with a concentration of 20wt%, with an oiling rate of 0.55%. The linear speed of the first guide roller section B is 1690 m / min, the temperature of the first hot roller is 52℃, and the linear speed of the first hot roller section B is 1700 m / min. The temperature of the second hot roller is 52℃, and the linear speed of the second hot roller section B is 1800 m / min. The temperature of the third hot roller is 102℃, and the linear speed of the third hot roller is 3200 m / min. The temperature of the fourth hot roller is 102℃, and the linear speed of the fourth hot roller is 3200 m / min. The linear speed of the second guide roller is 3220 m / min. The air pressure of the main network device is 0.4 MPa, the linear speed of the third guide roller is 3250 m / min, and the winding speed of the winding device is 3200 m / min.

[0104] The final snowflake-shaped bamboo filaments had a strip unevenness CV value of 24.6%, a bamboo node density of 42 nodes / meter, a breaking elongation of 86.9%, a breaking strength of 3.42 cN / dtex, a boiling water shrinkage rate of 34.1%, a filament downgrading rate of 0.05%, a breakage count of 6.8 times / 18 positions·24 hours, and a network density deviation of 3 nodes / meter (the standard network density value is 23 nodes / meter).

[0105] Example 3

[0106] A method for preparing snowflake-shaped bamboo joint fibers, the specific steps of which are as follows:

[0107] (1) Prepare fiber bundle A and fiber bundle B;

[0108] The preparation process of filament A is as follows: a matting agent (titanium dioxide) is added to PET melt with an intrinsic viscosity of 0.632 dL / g (PET is obtained by esterification and polycondensation reaction of PTA and EG, and the content of PTA in the reaction raw materials is 71 wt%). After that, it is sprayed out from the spinneret hole (circular cross-section) and cooled and shaped to obtain filament A with a specification of 65 dtex / 24f (the content of matting agent in the filament is 0.22 wt%).

[0109] The preparation process of filament bundle B is the same as that of filament bundle A;

[0110] (2) Preparation of snowflake-shaped bamboo strands;

[0111] Fiber bundle A is sequentially passed through pre-networker A, first guide roller A section, first hot roller A section, second hot roller A section, third hot roller, fourth hot roller, second oiling device and second guide roller. Fiber bundle B is sequentially passed through first oiling device, pre-networker B, first guide roller B section, first hot roller B section, second hot roller B section, third hot roller, fourth hot roller, second oiling device and second guide roller. Fiber bundles A and B are then simultaneously fed into the main networker for stranding, and then wound by the winding device via the third guide roller to obtain snowflake-shaped bamboo-joint filaments.

[0112] Both pre-networker A and pre-networker B have an air pressure of 0.35 MPa. Pre-networker A and pre-networker B have identical structures and dimensions. Pre-networker A is a vertical plate with a uniform cross-section and horizontally arranged airflow nozzles. A certain cross-section of pre-networker A passes through these nozzles. This cross-section is an Archimedean spiral with a polar angle of 420°, an Archimedean helix coefficient of 1.8 mm / °, and a polar diameter of 1.8 mm when the polar angle is 0°. The airflow nozzles are located at a position on the Archimedean spiral with a polar angle of 180°, facing the center of the Archimedean spiral. The airflow nozzles are circular orifices with a diameter of 1.2 mm, located vertically in the middle of pre-networker A. The length of pre-networker A in the vertical direction is 27 mm.

[0113] The guide hooks at the inlet and outlet of the pre-networker A are grooved guide hooks, which consist of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle A within the bottom area of ​​the U-shaped guide hook. The wire bundle A passes through the bottom area of ​​the upper grooved guide hook, the center of the pre-networker A, and the bottom area of ​​the lower grooved guide hook from top to bottom. In the vertical direction, the distance between the guide hooks at the inlet and outlet of the pre-networker A and the pre-networker A is 17mm. At the upper grooved guide hook, the angle α between the wire bundle A and the vertical direction is 9°. At the lower grooved guide hook, the angle β between the wire bundle A and the vertical direction is 9°.

[0114] The guide hooks at the inlet and outlet of the pre-networker B are grooved guide hooks, which consist of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle B within the bottom area of ​​the U-shaped guide hook. The wire bundle B passes through the bottom area of ​​the upper grooved guide hook, the center of the pre-networker B, and the bottom area of ​​the lower grooved guide hook from top to bottom. In the vertical direction, the distance between the guide hooks at the inlet and outlet of the pre-networker B and the pre-networker B is 17mm. The angle γ between the wire bundle B and the vertical direction at the upper grooved guide hook is 9°. The angle δ between the wire bundle B and the vertical direction at the lower grooved guide hook is 9°.

[0115] Each of the airflow nozzles of the pre-networker A and pre-networker B at each spinning station is connected to a branch pipe, and all the branch pipes are connected to the same main pipe. An automatic pressure regulating valve is installed on the air inlet end of the main pipe.

[0116] The first guide roller A section and the first guide roller B section are two length sections of the first guide roller. Both are cylindrical structures and coaxial. The diameter of the first guide roller A section is 97.35 mm, and the diameter of the first guide roller B section is 110 mm. The circumferential surface roughness of the first guide roller is uniform and is set to 1.5 μm.

[0117] The first hot roller section A and the first hot roller section B are two length sections of the first hot roller. Both are cylindrical structures and coaxial. The diameter of the first hot roller section A is 195 mm and the diameter of the first hot roller section B is 220 mm. The circumferential surface of the first hot roller is divided into two parts symmetrically distributed along the central axis of the first hot roller. The roughness of one part is 0.15 μm and the roughness of the other part is 1.5 μm.

[0118] The second hot roller section A and the second hot roller section B are two length sections of the second hot roller. Both are cylindrical structures and coaxial. The diameter of the second hot roller section A is 195 mm and the diameter of the second hot roller section B is 220 mm. The circumferential surface of the second hot roller is divided into two parts symmetrically distributed along the central axis of the second hot roller. The roughness of one part is 0.15 μm and the roughness of the other part is 1.5 μm.

[0119] The third hot roller has a cylindrical structure and a diameter of 220 mm. The surface roughness of the third hot roller is uniform and is 0.35 μm.

[0120] The fourth hot roller has a cylindrical structure and a diameter of 220 mm. The surface roughness of the fourth hot roller is uniform and is 0.35 μm.

[0121] Both filament bundle A and filament bundle B have 0.5 turns of winding on the first to fourth hot rollers;

[0122] Both the second and third guide rollers are cylindrical structures with a diameter of 110 mm and a uniform circumferential surface roughness of 1.5 μm.

[0123] The second oiling device is an integrated oil nozzle, while the first oiling device is an oil nozzle. The first oiling device uses crude oil for oiling, with an oiling rate of 0.5%. The second oiling device uses an oil agent with a concentration of 20.3 wt%, with an oiling rate of 0.58%. The linear speed of the first guide roller section B is 1690 m / min, the temperature of the first hot roller is 54℃, the linear speed of the first hot roller section B is 1700 m / min, the temperature of the second hot roller is 54℃, the linear speed of the second hot roller section B is 1800 m / min, the temperature of the third hot roller is 104℃, the linear speed of the third hot roller is 3200 m / min, the temperature of the fourth hot roller is 104℃, the linear speed of the fourth hot roller is 3200 m / min, the linear speed of the second guide roller is 3220 m / min, the air pressure of the main network device is 0.41 MPa, the linear speed of the third guide roller is 3250 m / min, and the winding speed of the winding device is 3250 m / min.

[0124] The final snowflake-shaped bamboo filaments had a strip unevenness CV value of 25.1%, a bamboo node density of 43 nodes / meter, a breaking elongation of 87.3%, a breaking strength of 3.39 cN / dtex, a boiling water shrinkage rate of 34.6%, a filament downgrading rate of 0.04%, a breakage count of 6.4 times / 18 positions·24 hours, and a network density deviation of 2 nodes / meter (the standard network density value is 22 nodes / meter).

[0125] Example 4

[0126] A method for preparing snowflake-shaped bamboo joint fibers, the specific steps of which are as follows:

[0127] (1) Prepare fiber bundle A and fiber bundle B;

[0128] The preparation process of filament A is as follows: a matting agent (titanium dioxide) is added to PET melt with an intrinsic viscosity of 0.635 dL / g (PET is obtained by esterification and polycondensation reaction of PTA and EG, and the content of PTA in the reaction raw materials is 70.3 wt%), and then it is sprayed out from the spinneret hole (the cross-section is circular) and cooled and shaped to obtain filament A with a specification of 73 dtex / 24f (the content of matting agent in the filament is 0.23 wt%).

[0129] The preparation process of filament bundle B is the same as that of filament bundle A;

[0130] (2) Preparation of snowflake-shaped bamboo strands;

[0131] Fiber bundle A is sequentially passed through pre-networker A, first guide roller A section, first hot roller A section, second hot roller A section, third hot roller, fourth hot roller, second oiling device and second guide roller. Fiber bundle B is sequentially passed through first oiling device, pre-networker B, first guide roller B section, first hot roller B section, second hot roller B section, third hot roller, fourth hot roller, second oiling device and second guide roller. Fiber bundles A and B are then simultaneously fed into the main networker for stranding, and then wound by the winding device via the third guide roller to obtain snowflake-shaped bamboo-joint filaments.

[0132] Both pre-networker A and pre-networker B have an air pressure of 0.36 MPa. Pre-networker A and pre-networker B have identical structures and dimensions. Pre-networker A is a vertical plate with a uniform cross-section and horizontally arranged airflow nozzles. A certain cross-section of pre-networker A passes through these nozzles; this cross-section is an Archimedean spiral with a polar angle of 400°, an Archimedean helix coefficient of 1.6 mm / °, and a polar diameter of 1.7 mm when the polar angle is 0°. The airflow nozzles are located at a position on the Archimedean spiral with a polar angle of 180°, facing the center of the Archimedean spiral. The airflow nozzles are circular orifices with a diameter of 1.2 mm, located vertically in the middle of pre-networker A. The length of pre-networker A in the vertical direction is 26 mm.

[0133] The guide hooks at the inlet and outlet of the pre-networker A are grooved guide hooks, which consist of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle A within the bottom area of ​​the U-shaped guide hook. The wire bundle A passes through the bottom area of ​​the upper grooved guide hook, the center of the pre-networker A, and the bottom area of ​​the lower grooved guide hook from top to bottom. In the vertical direction, the distance between the guide hooks at the inlet and outlet of the pre-networker A and the pre-networker A is 15mm. At the upper grooved guide hook, the angle α between the wire bundle A and the vertical direction is 10°. At the lower grooved guide hook, the angle β between the wire bundle A and the vertical direction is 10°.

[0134] The guide hooks at the inlet and outlet of the pre-networker B are grooved guide hooks, which consist of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle B within the bottom area of ​​the U-shaped guide hook. The wire bundle B passes from top to bottom through the bottom area of ​​the upper grooved guide hook, the center of the pre-networker B, and the bottom area of ​​the lower grooved guide hook. In the vertical direction, the distance between the guide hooks at the inlet and outlet of the pre-networker B and the pre-networker B is 15mm. The angle γ between the wire bundle B at the upper grooved guide hook and the vertical direction is 10°. The angle δ between the wire bundle B at the lower grooved guide hook and the vertical direction is 10°.

[0135] Each of the airflow nozzles of the pre-networker A and pre-networker B at each spinning station is connected to a branch pipe, and all the branch pipes are connected to the same main pipe. An automatic pressure regulating valve is installed on the air inlet end of the main pipe.

[0136] The first guide roller A section and the first guide roller B section are two length sections of the first guide roller. Both are cylindrical structures and coaxial. The diameter of the first guide roller A section is 100 mm and the diameter of the first guide roller B section is 110 mm. The circumferential surface roughness of the first guide roller is uniform and is set to 1.4 μm.

[0137] The first hot roller section A and the first hot roller section B are two length sections of the first hot roller. Both are cylindrical structures and coaxial. The diameter of the first hot roller section A is 200 mm and the diameter of the first hot roller section B is 220 mm. The circumferential surface of the first hot roller is divided into two parts symmetrically distributed along the central axis of the first hot roller. The roughness of one part is 0.15 μm and the roughness of the other part is 1.4 μm.

[0138] The second hot roller section A and the second hot roller section B are two length sections of the second hot roller. Both are cylindrical structures and coaxial. The diameter of the second hot roller section A is 200 mm and the diameter of the second hot roller section B is 220 mm. The circumferential surface of the second hot roller is divided into two parts symmetrically distributed along the central axis of the second hot roller. The roughness of one part is 0.15 μm and the roughness of the other part is 1.4 μm.

[0139] The third hot roller has a cylindrical structure and a diameter of 220 mm. The surface roughness of the third hot roller is uniform and is 0.35 μm.

[0140] The fourth hot roller has a cylindrical structure and a diameter of 220 mm. The surface roughness of the fourth hot roller is uniform and is 0.35 μm.

[0141] Both filament bundle A and filament bundle B have 0.5 turns of winding on the first to fourth hot rollers;

[0142] Both the second and third guide rollers are cylindrical structures with a diameter of 110 mm and a uniform circumferential surface roughness of 1.4 μm.

[0143] The second oiling device is an integrated oil nozzle, while the first oiling device is an oil nozzle. The first oiling device uses crude oil for oiling, with an oiling rate of 0.48%. The second oiling device uses an oil agent with a concentration of 20.5 wt%, with an oiling rate of 0.6%. The linear speed of the first guide roller section B is 1690 m / min, the temperature of the first hot roller is 55℃, and the linear speed of the first hot roller section B is 1700 m / min. The temperature of the second hot roller is 55℃, and the linear speed of the second hot roller section B is 1800 m / min. The temperature of the third hot roller is 105℃, and the linear speed of the third hot roller is 3200 m / min. The temperature of the fourth hot roller is 105℃, and the linear speed of the fourth hot roller is 3200 m / min. The linear speed of the second guide roller is 3220 m / min. The air pressure of the main network device is 0.42 MPa, the linear speed of the third guide roller is 3250 m / min, and the winding speed of the winding device is 3275 m / min.

[0144] The final snowflake-shaped bamboo filaments had a strip unevenness CV value of 26.3%, a bamboo node density of 45 nodes / meter, a breaking elongation of 88.5%, a breaking strength of 3.35 cN / dtex, a boiling water shrinkage rate of 34.3%, a filament downgrading rate of 0.06%, a breakage count of 5.7 times / 18 positions·24 hours, and a network density deviation of 3 nodes / meter (the standard network density value is 23 nodes / meter).

[0145] Example 5

[0146] A method for preparing snowflake-shaped bamboo filaments differs from Example 1 only in that the polar angle of the Archimedes spiral is 350°.

[0147] The final snowflake-shaped bamboo filaments had a strip unevenness CV value of 21.9%, a bamboo node density of 37 nodes / meter, a breaking elongation of 86.1%, a breaking strength of 3.45 cN / dtex, a boiling water shrinkage rate of 33.5%, a filament downgrading rate of 0.07%, a breakage count of 8.0 times / 18 positions·24 hours, and a network density deviation of 3 nodes / meter.

[0148] Compared with Example 1, Example 5 shows a decrease in the uniformity CV value and bamboo density of snowflake-shaped bamboo strands, and an increase in the rate of fuzzy filament degradation and the number of breakages. This is because when the polar angle of the Archimedes spiral is 350°, the larger network air pressure is discharged from the pre-networker earlier, resulting in a decrease in network density, which in turn leads to a decrease in bamboo density and uniformity CV value. At the same time, the early discharge of air pressure causes the air pressure in the inner chamber of the pre-networker to be unstable, and the filament bundles are more likely to rub against the edge of the pre-networker, resulting in an increase in fuzzy filaments and the number of breakages.

[0149] Example 6

[0150] The method for preparing snowflake-shaped bamboo filaments differs from Example 2 only in that the polar angle of the Archimedes spiral is 460°.

[0151] The final snowflake-shaped bamboo filaments had a strip unevenness CV value of 23.8%, a bamboo node density of 41 nodes / meter, a breaking elongation of 87.1%, a breaking strength of 3.40 cN / dtex, a boiling water shrinkage rate of 34.0%, a filament downgrading rate of 0.07%, a breakage count of 7.9 times / 18 positions·24 hours, and a network density deviation of 3 nodes / meter.

[0152] Compared with Example 2, Example 6 shows an increase in the rate of filament degradation and the number of breakages in the snowflake-shaped bamboo joint filaments. This is because when the polar angle of the Archimedes spiral is 460°, a large network air pressure cannot be discharged from the pre-networker in time, causing airflow turbulence in the pre-networker, which in turn increases the number of filaments and breakages.

[0153] Example 7

[0154] A method for preparing snowflake-shaped bamboo filaments differs from Example 1 only in that: in pre-networker A and pre-networker B, the airflow nozzle is located at a position with a polar angle of 170° on the Archimedean spiral.

[0155] The final snowflake-shaped bamboo filaments had a strip unevenness CV value of 21.3%, a bamboo node density of 36 nodes / meter, a breaking elongation of 86.2%, a breaking strength of 3.49 cN / dtex, a boiling water shrinkage rate of 33.8%, a filament downgrading rate of 0.07%, a breakage count of 8.1 times / 18 positions·24 hours, and a network density deviation of 3 nodes / meter.

[0156] Compared with Example 1, Example 7 shows a decrease in the uniformity (CV) of the snowflake-shaped bamboo strands and a decrease in bamboo strand density, while an increase in the rate of downgrading of fuzz and the number of breakages. This is because when the airflow nozzle is located at an extreme angle of 170°, the airflow from the pre-networking device blows directly into another spiral channel inside the pre-networking device after being blown onto the strands, causing unstable air pressure in the inner chamber of the pre-networking device, which reduces the density of bamboo strands and uniformity of the strands. At the same time, the turbulent air pressure causes the strands to easily rub against the edge of the pre-networking device, exacerbating the fuzz and breakage phenomena.

[0157] Example 8

[0158] A method for preparing snowflake-shaped bamboo-joint filaments differs from Example 1 only in that the guide hooks at the inlet and outlet of pre-networker A and pre-networker B are both U-shaped guide hooks.

[0159] The final snowflake-shaped bamboo filaments had a strip unevenness CV value of 23.2%, a bamboo node density of 39 nodes / meter, a breaking elongation of 86.1%, a breaking strength of 3.49 cN / dtex, a boiling water shrinkage rate of 33.9%, a filament downgrading rate of 0.09%, a breakage count of 8.1 times / 18 positions·24 hours, and a network density deviation of 5 nodes / meter.

[0160] Compared with Example 1, Example 8 shows an increase in the rate of fuzz reduction, number of breakages, and network deviation of the snowflake-shaped bamboo joint filaments. This is because the angle of filament bundle A before and after pre-networker A is large, and the angle of filament bundle B before and after pre-networker B is also large. The use of U-shaped guide hooks will cause filament bundles A and B to be unable to be locked in the middle position of pre-networker A and pre-networker B respectively under the high pre-network air pressure, resulting in inconsistent force points and uneven network points. At the same time, due to the inconsistent force points, filament bundles A and B are more likely to rub against the edges of pre-networker A and pre-networker B, which in turn leads to an increase in fuzz and breakages.

[0161] Example 9

[0162] A method for preparing snowflake-shaped bamboo joint fibers differs from Example 1 only in that: both pre-networker A and pre-networker B are replaced with the pre-networker from patent application CN109594137A (cross-section as shown in Figure 1). Figure 2 (as shown in a).

[0163] The resulting snowflake-shaped bamboo filaments had a strip unevenness CV value of 23.7%, a bamboo node density of 41 nodes / meter, a breaking elongation of 86.1%, a breaking strength of 3.42 cN / dtex, a boiling water shrinkage rate of 32.4%, a filament downgrading rate of 0.13%, a breakage count of 8.9 times / 18 positions·24 hours, and a network density deviation of 6 nodes / meter.

[0164] Compared with Example 1, Example 9 shows an increase in the rate of fuzz reduction, number of breakages, and network deviation of snowflake-shaped bamboo joint filaments. This is because, under higher pre-networking air pressure, the spiral airflow cannot be discharged in an orderly manner using the existing pre-networking device, resulting in turbulent air pressure in the inner chamber of the pre-networking device and significant shaking of the filament bundle, leading to uneven network points. Filament bundle A was not oiled before pre-networking, lacking oil protection, and is prone to fuzz and breakage under the impact of high-pressure airflow. The existing pre-networking device has obstructed airflow discharge, increasing friction between the filament bundle and the pre-networking device, which exacerbates fuzz formation.

Claims

1. A method for preparing snowflake-shaped bamboo joint fibers, characterized in that, Fiber bundles A and B are simultaneously fed into the main networker for stranding, and then wound by the winding device via the third guide roller. Before being fed into the main networker, the filament bundle A passes through the pre-networker A, the first guide roller A section, the first hot roller A section, the second hot roller A section, the third hot roller, the fourth hot roller, the second oiling device, and the second guide roller in sequence. Before being fed into the main networker, the filament bundle B passes through the first oiling device, the pre-networker B, the first guide roller section B, the first hot roller section B, the second hot roller section B, the third hot roller, the fourth hot roller, the second oiling device, and the second guide roller in sequence. The first guide roller section A and the first guide roller section B are two length segments of the first guide roller. Both are cylindrical structures and coaxial. The diameter of the first guide roller section B is 1.1-1.2 times the diameter of the first guide roller section A. The circumferential surface roughness of the first guide roller is uniform, with a value range of 1.3-1.5μm. The first hot roller section A and the first hot roller section B are two length segments of the first hot roller. Both are cylindrical structures and coaxial. The diameter of the first hot roller section B is 1.1-1.2 times the diameter of the first hot roller section A. The circumferential surface of the first hot roller is divided into two parts symmetrically distributed along the central axis of the first hot roller. The roughness of one part is 0.1-0.15μm, and the roughness of the other part is 1.3-1.5μm. The second hot roller section A and the second hot roller section B are two length segments of the second hot roller. Both are cylindrical structures and coaxial. The diameter of the second hot roller section B is 1.1-1.2 times the diameter of the second hot roller section A. The circumferential surface of the second hot roller is divided into two parts symmetrically distributed along the central axis of the second hot roller. The roughness of one part is 0.1-0.15μm, and the roughness of the other part is 1.3-1.5μm. The surface roughness of the third hot roller is uniform, ranging from 0.30 to 0.35 μm. The surface roughness of the fourth hot roller is uniform, ranging from 0.30 to 0.35 μm. Both filament bundle A and filament bundle B have 0.5 turns of winding on the first to fourth hot rollers; The air pressure of pre-networker A and pre-networker B is 0.34-0.36 MPa; The linear speed of the first guide roller section B is 1690 m / min, the temperature of the first hot roller is 50-55℃, the linear speed of the first hot roller section B is 1700 m / min, the temperature of the second hot roller is 50-55℃, the linear speed of the second hot roller section B is 1800 m / min, the temperature of the third hot roller is 100-105℃, the linear speed of the third hot roller is 3200 m / min, the temperature of the fourth hot roller is 100-105℃, the linear speed of the fourth hot roller is 3200 m / min, the linear speed of the second guide roller is 3220 m / min, the linear speed of the third guide roller is 3250 m / min, and the winding speed of the winding device is 3175-3275 m / min.

2. The method for preparing snowflake-shaped bamboo-joint fibers according to claim 1, characterized in that, The initial oiling device is an oil nozzle; The pre-networker A is a vertical plate with a uniform cross-section and horizontally arranged airflow nozzles. A certain cross-section of the pre-networker A passes through the airflow nozzles. The cross-section is an Archimedean spiral with a polar angle greater than 360° and less than 450°. The airflow nozzles are located at a position with a polar angle of 180° on the Archimedean spiral and face the center of the Archimedean spiral. The structure and dimensions of pre-networker B are the same as those of pre-networker A; The guide hooks at the inlet and outlet of the pre-networker A are grooved guide hooks. The grooved guide hook consists of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle A in the bottom area of ​​the U-shaped guide hook. The filament bundle A passes from top to bottom through the bottom area of ​​the upper grooved guide hook, the center of the pre-networker A, and the bottom area of ​​the lower grooved guide hook. The guide hooks at the inlet and outlet of the pre-networker B are grooved guide hooks. The grooved guide hook consists of a U-shaped guide hook and a limiting block. The U-shaped guide hook is arranged horizontally, and the limiting block is connected to the inner wall of the U-shaped guide hook to limit the wire bundle B in the bottom area of ​​the U-shaped guide hook. The wire bundle B passes from top to bottom through the bottom area of ​​the upper grooved wire guide hook, the center of the pre-networker B, and the bottom area of ​​the lower grooved wire guide hook.

3. The method for preparing snowflake-shaped bamboo-joint fibers according to claim 2, characterized in that, The Archimedean spiral has an Archimedean spiral coefficient of 1-2 mm / ° and a polar diameter of 1.5-2 mm when the polar angle is 0°. The airflow nozzle is a circular orifice with a diameter of 1.1-1.3 mm. In the vertical direction, the airflow nozzle is located in the middle of the pre-networker A. In the vertical direction, the length of the pre-networker A is 23-27 mm.

4. The method for preparing snowflake-shaped bamboo joint fibers according to claim 2, characterized in that, Along the vertical direction, the distance between the guide hook at the inlet and outlet of the pre-networker A and the pre-networker A is 13-17mm; the angle α between the wire bundle A at the upper grooved guide hook and the vertical direction is 5-10°; the angle β between the wire bundle A at the lower grooved guide hook and the vertical direction is 5-10°. Along the vertical direction, the distance between the guide hook at the inlet and outlet of the pre-networker B and the pre-networker B is 13-17mm; the angle γ between the wire bundle B at the upper grooved guide hook and the vertical direction is 5-10°; the angle δ between the wire bundle B at the lower grooved guide hook and the vertical direction is 5-10°.

5. The method for preparing snowflake-shaped bamboo-joint fibers according to claim 2, characterized in that, Each of the airflow nozzles of the pre-networker A and pre-networker B at each spinning station is connected to a branch pipe, and all the branch pipes are connected to the same main pipe, which is equipped with an automatic pressure regulating valve at the air inlet end.

6. The method for preparing snowflake-shaped bamboo joint fibers according to claim 1, characterized in that, The air pressure of the main network unit is 0.38-0.42 MPa.

7. The method for preparing snowflake-shaped bamboo-joint fibers according to claim 6, characterized in that, The second oiling device is an integrated oil nozzle; the first oiling device uses crude oil for oiling, with an oiling rate of 0.4-0.5%; the second oiling device uses an oil agent with a concentration of 19.5-20.5wt% for oiling, with an oiling rate of 0.5-0.6%.

8. The method for preparing snowflake-shaped bamboo joint fibers according to claim 1, characterized in that, Both filament bundle A and filament bundle B contain 0.21-0.23 wt% matting agent, and the specifications of filament bundle A and filament bundle B are 50-73 dtex / 24f.

9. A method for preparing snowflake-shaped bamboo-joint fibers according to any one of claims 1-8, characterized in that, The uniformity (CV) of snowflake-shaped bamboo filaments is 21.3-26.3%, the density of bamboo nodes is 36-45 per meter, the elongation at break is 86-88%, the breaking strength is above 3.2 cN / dtex, the shrinkage rate in boiling water is 30-35%, the downgrading rate of filaments is ≤0.13%, the number of breakages is ≤8.9 times / 18 positions·24 hours, and the network degree deviation is ≤6 per meter.

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