Bio-based polyamide modified raw material composition for improving hairiness distribution on surface of bunchy yarn

Abstract

The invention relates to the technical field of bio-based polyamide modification, and discloses a bio-based polyamide modified raw material composition for improving the surface hairiness distribution of bunchy yarn, which comprises the following components in percentage by mass: 2.5-6.0% of bio-based polyamide 1010 resin, 0.5-2.0% of maleic anhydride grafted castor oil polyether with the weight-average molecular weight of 3500-5500g / mol, 0.5-2.0% of maleic anhydride grafted castor oil polyether with the weight-average molecular weight of 3,500-5,500 g / mol, 0.5-2.0% of maleic anhydride grafted castor oil polyether with the weight-average molecular weight of 3,500-5,500 g / mol, the functional components are driven to migrate to a surface layer and generate interface secondary bonding by utilizing reaction activity and temperature drop rate coupling among the components and a temperature drop rate difference generated corresponding to an axial variable cross section of the slub yarn, and a thickness heterogeneous interface layer is spontaneously constructed at slubs and details; the technical contradiction that a homogeneous modified material cannot be matched with a non-uniform thermal field is solved, and the physical integrity of the fiber surface is improved.

Description

Technical Field

[0001] This invention relates to a bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn, belonging to the field of bio-based polyamide modification technology. Background Technology

[0002] The diameter of the current slub yarn fiber changes periodically with its length, resulting in a twist gradient during the twisting process. The twist is low in the slub section with a larger diameter, and the fiber binding force is weak.

[0003] While conventional methods of increasing viscosity or oil content improve fiber adhesion in low-twist areas, they also cause charge accumulation in high-twist fine areas. This charge accumulation leads to fluctuations in the coefficient of dynamic friction, inducing fiber ends to extend towards the surface. Conventional homogeneous modification schemes ignore the crystallization kinetics and stress relaxation fluctuations of the melt during the variable cross-section cooling process, resulting in the material's inability to sense differences in the axial thermal field and causing performance imbalances. For example, Chinese invention patent CN1904168B discloses a method for producing intertwisted slub yarn, which uses a servo motor to control the speed of the middle and back rollers, combining the intertwisting effect of two identical rovings to improve strength and suppress hairiness. This type of technology improves the mechanical properties of the weak-twist area in terms of macroscopic physical structure, which is essentially an external mechanical compensation. It ignores the crystallization kinetics and stress relaxation endogenous fluctuations of the modified melt during the variable cross-section cooling process, resulting in the material's inability to sense and match the microenvironmental differences in the axial thermal field.

[0004] Therefore, the technical problem to be solved by this invention is how to provide a modified composition with a thermal hysteresis dynamic anchoring mechanism that spontaneously generates an asymmetric interface structure in the non-uniform thermal process of slub yarn, and solve the problem that traditional solutions cannot match the cooling differences of variable cross sections, resulting in insufficient hair suppression at the slub joint. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: a bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn, comprising:

[0006] Component B, by weight percentage, is 2.5% to 6.0%, and Component B is bio-based polyamide 1010 resin;

[0007] 0.5% to 2.0% of component C, which is maleic anhydride-grafted castor oil polyether;

[0008] And the balance of component A, which is a bio-based polyamide 56 resin with a relative viscosity of 2.4 to 2.8;

[0009] Among them, the weight-average molecular weight of component C is 3500 g / mol to 5500 g / mol, and the maleic anhydride grafting rate of component C is 0.8% to 1.5%;

[0010] The melting point of component B is 15 degrees lower than that of component A. Up to 25 ;

[0011] The composition was extruded via a co-rotating twin-screw extruder at 260°C. Up to 275 The melt reaction extrusion is carried out within the temperature range, so that component C and the terminal amino group of component A undergo a coupling reaction to generate a polyamide 56 block product containing castor oil polyether branches.

[0012] During the spinning and cooling process, the composition corresponds to a temperature drop rate difference of 25% to 40% caused by the difference in axial diameter of the slub yarn. The polyamide 56 block product migrates to the fiber surface and undergoes interfacial bonding with the component β. The thickness of the interfacial layer formed at the slub of the slub yarn is 150 nm to 300 nm, and the thickness of the interfacial layer formed at the details of the slub yarn is 30 nm to 50 nm.

[0013] Preferably, component B has a melting point of 200°C. Up to 205 Component B at 230 The melt index under a load of 2.16 kg is 15 g / 10 min to 25 g / 10 min; the terminal amino content of component A is 45 mol / t to 55 mol / t; and the composition is suitable for use at a cooling rate of 1000 °C. The thickness of the interface layer formed under conditions of / s is similar to that formed at a temperature drop rate of 2000. The ratio of the thickness of the interface layer formed under the condition of / s is 3 to 10.

[0014] Preferably, the composition satisfies the following viscosity matching rule: ,in, This refers to the viscosity ratio, with values ​​ranging from 1.05 to 1.20. For the composition at 260 Apparent viscosity under a shear rate of 1000 / s; Let be the apparent viscosity of component A under the same test conditions.

[0015] Preferably, component C is in 100 The kinematic viscosity is 400 mm² / s to 600 mm² / s; the castor oil polyether segment in component propylene contains 20 to 40 repeating ethylene oxide units.

[0016] Preferably, the composition is prepared by the following steps: Step 1, components A, B and C are respectively heated at 105 °C. Up to 115 The components are vacuum dried for 8 to 12 hours until the moisture content of each component is below 200 ppm. In step two, the dried components A, B, and C are fed into a high-speed mixer for dry mixing, so that component C coats the surface of component A. In step three, the mixed raw materials are added to a co-rotating twin-screw extruder and extruded at 260°C. Up to 275 The mixture is then subjected to a melt reaction and extrusion.

[0017] Preferably, in step three, the screw length-to-diameter ratio of the co-rotating twin-screw extruder is 44:1, the screw speed is set to 300 rpm to 500 rpm, and the residence time of the melt in the reaction zone of the twin-screw extruder is 30 seconds to 50 seconds.

[0018] Preferably, component A contains 0.05% to 0.15% by mass of a terminal amino modifier, wherein the terminal amino modifier is terephthalic acid, used to control the molar ratio of the terminal amino group of component A to the maleic anhydride group of component C to be between 1:0.8 and 1:1.2.

[0019] Preferably, component C has a comb-like structure, and its branches are castor oil polyether segments with oleophilic properties, which are used to provide internal lubrication in the molten state and reduce the interfacial tension between component B and component A.

[0020] Preferably, the composition exhibits the following surface tension characteristics at different temperature cooling rates: the composition at a temperature cooling rate of 1000°C... The surface tension at / s is greater than that at a temperature decreasing rate of 2000. The surface tension is 15% to 25% lower at / s.

[0021] Preferably, the composition is used to manufacture bio-based polyamide fibers.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. In improving the surface hair distribution of slub yarn, the composition utilizes the coupling of the reaction activation energy between components and the temperature drop rate to achieve spontaneous matching of the interface modification layer thickness with the axial change of fiber diameter. In the slub section with a larger diameter, the internal thermal hysteresis effect of the material prolongs the residence time of the functionalized components in the reaction temperature zone, driving the surface layer of the components to complete high-density chemical pinning, forming a highly cohesive flexible protective layer, and inhibiting hair escape in low-twist areas. In the fine parts with extremely rapid temperature drop, the interface reaction terminates rapidly with the sudden drop in temperature, maintaining an ultra-thin lubricating layer.

[0024] 2. The low surface energy migration characteristics of component B and the multi-site anchoring effect of component C produce spatial synergistic gains. Component C is pre-coupled with the matrix during the melt reaction extrusion process, and the intermediate generated plays a synergistic guiding role in the spinning process, driving component B to enrich towards the fiber surface. Component C forms a comb-like structure through a specific weight-average molecular weight, locking the enriched lubricating phase on the matrix surface and forming a heterogeneous interface structure with thermomechanical process memory effect. Physical migration and chemical bonding are deeply coupled, avoiding the shedding or disordered distribution of conventional lubricating components under high-speed friction conditions, and improving the physical integrity of the fiber surface.

[0025] 3. The composition constructs a chemical pinning network on the fiber surface. Based on the viscoelastic response characteristics of the interface layer, it undergoes a high shear stress process such as high-speed steel ring friction. The interface layer dissipates stress energy through the sliding of flexible long branched molecular chains, avoiding local tearing of polyamide molecular chains caused by dry friction. The interface layer stress relief mechanism cuts off the physical path of the fiber end extending to the surface, so that the fiber exhibits a surface-like self-closing protective function, ensuring the clarity of the opening and the stability of the process in the subsequent weaving of slub yarn. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the preparation process and interface mechanism of the modified nanocellulose-reinforced slub yarn of the present invention.

[0027] Figure 2 This is a comparative graph showing the correlation between the evolution of interface layer thickness and the coefficient of variation of hair under different component ratios of the present invention.

[0028] Figure 3 This is a fishbone diagram illustrating the key technical elements of raw materials, processes, and structures for improving the surface hair distribution of slub yarn in this invention. Detailed Implementation

[0029] The present invention will be described below through specific embodiments. It should be understood that the following embodiments are for explanation and illustration, and not for limiting the scope of protection of the present invention.

[0030] This invention provides a bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn. By coupling the reactivity between components with the rate of temperature drop, and utilizing the thermal hysteresis difference generated by the axial cross-section change during the spinning process of slub yarn, the functional components are driven to migrate to the fiber surface and undergo interfacial anchoring, thereby constructing a heterogeneous interfacial layer of varying thickness at the slub and fine areas. The composition includes components... Components and components Components For relative viscosity at to Bio-based polyamides within the range Resin, its mass percentage is to As a matrix component that builds fiber strength, the component Bio-based polyamides were selected. Resin, its mass percentage is to And components Melting point ratio of components Low melting point to Components Maleic anhydride-grafted castor oil polyether was used, with a mass percentage of [missing information]. to Weight-average molecular weight for g / mol to g / mol, its maleic anhydride grafting rate to During the preparation stage, the components are... Components With components Placed to Vacuum drying at temperature Hours to Hours, so that the moisture content of each component decreases to Below ppm, the dried raw materials are fed into a high-speed mixer, where... Mixing at rpm minutes, make the components Uniformly coated on the components On the surface of the slice, the mixture is added to the slice with an aspect ratio of In a co-rotating twin-screw extruder, to Melt reaction extrusion within a temperature range; within this temperature window, the components... maleic anhydride groups and components The terminal amino groups undergo pre-coupling to generate polyamides containing castor oil polyether branches. Block products.

[0031] The composition corresponds to the difference in axial diameter of the slub yarn during the fiber spinning and cooling process. to The temperature drop rate difference is significant. In the bamboo joint area, the fiber diameter is larger and the cooling rate is slower, resulting in a longer residence time of the material above the reaction temperature. At this point, the components... Secondary chemical bonding is completed at the interface layer, forming a flexible interface layer that allows the migrated components to pass through. Locked in the surface, the resulting interface layer has a thickness of nm to nm, in the finer details where the cooling rate is faster, the interfacial reaction terminates as the temperature decreases, and the resulting interfacial layer thickness is [missing value]. nm to nm; the properties of this composition satisfy the following viscosity matching rule: ,in The viscosity ratio is [value missing]. to ; For the composition in shear rate Apparent viscosity under the given conditions; Components Apparent viscosity under the same test conditions; for adjusting the components The content of terminal amino groups, the percentage by mass in the matrix is to Terephthalic acid is used as a terminal amino modifier to modify the components. terminal amino groups and components The molar ratio of maleic anhydride groups is controlled at to Within the range, components It has a comb-like structure, and its branches are contained to Castor oil polyether segments of repeating ethylene oxide units are used to provide lubrication and reduce component density. With components The interfacial tension between them, this interfacial modulation mechanism allows the composition to operate at a temperature drop rate of... The surface tension at / s is greater than that at a temperature drop rate of . Low surface tension at / s to Transmission electron microscopy was used to characterize the cross-sectional morphology of the fiber samples. The embedded fiber sections were stained with 2% phosphotungstic acid at room temperature. The polyether segments in the component propylene formed a complex with phosphotungstic acid, exhibiting high contrast under electron beam. The grayscale distribution curve of the image was extracted to define the interface boundary. The edge of the interface layer was defined as the position extending from the outermost edge of the fiber inwards to where the grayscale value decays to 110% of the matrix background value. The thickness of the interface layer at the bamboo joint was calculated. Interface layer thickness at details , The thickness of the interface layer at the bamboo joint. The thickness of the interface layer at the details.

[0032] To ensure that the composition can stably form a thickness at different ambient temperatures. nm to A nm-level interface layer is added to eliminate process deviations caused by fluctuations in cooling airflow, located below the spinning spinneret outlet. An infrared temperature distribution sensor is installed at point m to monitor the axial temperature gradient of the molten stream leaving the spinneret in real time. Using the controller according to the components mass percentage Establish side blowing speed An adaptive compensation model is used to ensure that wind speeds satisfy the following proportional relationship: ,in The side-blowing wind speed is expressed in m / s. This is the thermal conductivity correction factor, whose value was determined in the offline calibration experiment. ; This represents the measured temperature gradient, in units of... / m; The diameter of the bamboo node is measured in meters (m). The diameter of the detailed part is in meters. Under this specification, when the ambient temperature is... When fluctuations occur within a certain range, the effective response process at the bamboo joint is adjusted by regulating the frequency of the side-blowing motor. Locked in s to Within the s-range; during the spinning process debugging, an infrared temperature distribution sensor was installed 0.5m below the spinneret outlet to obtain the temperature distribution gradient of the melt stream. The sensor has a frame rate of at least 2000Hz and a performance better than 0.1. Sensitivity and output signal are processed by the control module to drive the inverter of the side blowing system and adjust the side blowing speed. According to the formula Set the initial wind speed for the production batch. For temperature distribution gradient, This refers to the side-blowing wind speed. The value is a thermal conductivity correction factor of 0.045. The diameter of the bamboo node. To control the diameter of the detailed parts, the bamboo joint is kept above the reaction temperature window for a specific duration by adjusting the closed-loop control. Locked in the range of 1.8s to 2.2s, The residence time is used to induce component C to complete a predetermined ratio of chemical bonding on the fiber surface.

[0033] Example 1: In this example, the spinning speed is... m / min bio-based polyamide In the processing environment of slub yarn, alternating changes in the axial cross-sectional area of ​​the fibers cause a lack of twist distribution in the larger diameter slub sections. This leads to the single fibers in these sections escaping outwards due to weak binding force, forming long fuzz. Simultaneously, the smaller diameter finer sections experience surface pressure buildup due to high twist, inducing static electricity. In this situation, the composition of the present invention utilizes the temperature drop rate at the slub sections... The thermal hysteresis effect generated by / s results in a mass percentage of . Components , Components as well as Components The mixed system in The above effective reaction process is prolonged, driving the component Migrate to the surface and by components Anchored at the fiber interface to create a thickness A flexible skin layer of nm.

[0034] While the cooling rate is In the detailed areas of / s, the interface reaction terminates as the temperature decreases, maintaining the interface layer thickness at / s. nm, utilizing this non-axisymmetric interface structure to offset the mechanical constraint differences caused by the twist gradient, and to maintain the viscosity ratio over the entire yarn length. Constant The level, viscosity ratio Satisfy the formula ,in Viscosity ratio For the composition in and shear rate Apparent viscosity under certain conditions Components Under the same conditions, the apparent viscosity ultimately dissipates high-speed frictional stress through the interface structure and inhibits the germination of hairs in the low twist region.

[0035] Example 2: This example is constructed on a melt spinning experimental line equipped with an online variable cross-section drafting control system, and has a length-to-diameter ratio of... The co-rotating twin-screw reactive extruder and the rotary drum vacuum drying equipment were tested in an environment below the spinning spinneret. A side-blowing disturbance source with Gaussian white noise distribution is installed at point m, and its signal-to-noise ratio is set to [value missing]. dB is used to simulate turbulent conditions in an industrial workshop, with data acquisition originating from a sampling frequency of [frequency missing]. A Hz online laser feather detector with a measurement resolution of mm and the measurement range covers mm to The feather length in mm was used to simulate the periodic diameter changes in bamboo nodes and detailed areas by adjusting the draft ratio. Double The switching frequency between multiples, and the consideration in setting the sampling period, is to balance data real-time performance with processor computational load. When the diameter of the monitored fiber changes abruptly at a frequency of... At Hz, to capture instantaneous changes in feather distribution, the sampling period is set to the reciprocal of its corresponding frequency. times ms, the logical anchoring of experimental parameters lies in using to The drying temperature reduces the moisture content to a minimum. Below ppm.

[0036] During the preparation of the test samples, the components were dry-mixed and melt-extruded according to the standardized operating procedures described in the aforementioned specific embodiments, and the temperature of the feeding zone of the twin-screw extruder was set to [temperature value missing]. The temperature of the melting zone is The temperature of the reaction zone is to The residence time of the melt in the reaction zone is locked by adjusting the screw speed. s, making the components maleic anhydride groups and components The terminal amino groups complete the interfacial pre-coupling, and the resulting slices are processed on the above-mentioned spinning experimental line, maintaining the slub joint. The temperature drop rate of / s is maintained in detail. The temperature drop rate per second is determined by adjusting the amount of terephthalic acid added to the components. The content of terminal amino groups is stable at mol / t, to maintain the reaction molar ratio at Near the chemical equilibrium point, Table 1 records the physical parameters of the compositions and the coefficient of variation of yarn hairiness under different component ratios. Comparative data.

[0037] Table 1: Examples of Composition Performance Validation Results

[0038]

[0039] Referring to the data in Table 1, control group 1 was used as the pure component. The matrix, in the absence of interface regulation mechanisms, has a feathering variation coefficient of _____. This indicates that the feathers systematically aggregate at the bamboo nodes, while control group 2, although it introduced components... However, it lacks a component that serves as an anchoring module. This results in the interface layer thickness being only [missing information]. nm, components Unable to adhere stably at the interface and prone to loss in shear fields, test groups 1 to 3 correspond to the above-mentioned component range, with viscosity ratios... Stable at to Within the range, viscosity ratio Satisfy the formula ,in Viscosity ratio For the composition in and shear rate Apparent viscosity under certain conditions Components Apparent viscosity under the same conditions, and the interfacial layer thickness at the bamboo joint varies with the composition. The content increases in a gradient, proving that the thermal hysteresis effect successfully drives the directional migration and chemical pinning of functional components. Content exceeding The upper limit is as shown in group 1 (out of range), viscosity ratio Rise to This deterioration is accompanied by a rebound in the coefficient of variation of the feathering, which stems from the formation of localized gel points caused by excessive cross-linking, thereby disrupting the continuous slip properties of the interfacial layer. Meanwhile, in the component... In group 2, which is below the lower limit, the insufficient concentration of the migrating phase prevents the formation of a dense cortex sufficient to cover the ends of single fibers on the surface, resulting in a decrease in the effect of inhibiting hair growth.

[0040] Example 3: This example combines Figures 1 to 3 A description of a bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn, such as... Figure 1 As shown, the input end includes three parallel raw material modules: modified nanocellulose (MNC) as a reinforcing phase and structure regulator to build an internal network and reduce hairiness; a bio-based polyamide matrix as the main component to provide basic mechanical properties and fiber-forming properties; and a combination of functional additives containing chain extenders, antioxidants, and lubricants to optimize interfacial bonding and processing rheology. The above raw materials converge into the melt blending and spinning process, which is defined as the process of uniformly mixing the components and forming them into yarn. The resulting interfacial synergistic mechanism is manifested as the physical / chemical bonding between the MNC and the matrix. This mechanism improves the interfacial strength while inhibiting the propagation of microcracks. The final output product is a slub yarn with improved hairiness distribution and more uniform surface hairiness distribution.

[0041] like Figure 2As shown, this composite chart uses the left vertical axis to indicate the interface layer thickness in nm and the right vertical axis to indicate the hairiness coefficient of variation in %. The horizontal axis includes seven sample categories: control group 1, control group 2, experimental group 1, experimental group 2, experimental group 3, out-of-range group 1, and out-of-range group 2. The bar chart corresponds to the interface layer thickness at the slub joint as shown in the legend, and the line chart corresponds to the total yarn hairiness coefficient of variation as shown in the legend. Among them, the interface layer thickness of control group 1 is close to 0 and the hairiness coefficient of variation is the highest. As the interface layer thickness of experimental groups 1 to 3 gradually increases from 150 nm to the 300 nm range, the corresponding hairiness coefficient of variation shows a decreasing trend. Although out-of-range group 1 has the largest interface layer thickness, the hairiness coefficient of variation rebounds. Out-of-range group 2 shows a lower interface layer thickness and a higher hairiness coefficient of variation. Figure 3 As shown, this fishbone diagram aims to improve the surface hair distribution of slub yarn. Its main branch connects four main branches: raw material component system, reaction molding process, thermodynamic mechanism, and interfacial structure characteristics. The raw material component system branch lists bio-based polyamide 56 resin component A as the matrix and high-viscosity component, bio-based polyamide 1010 component B as the low-melting-point migrating phase, and maleic anhydride-grafted castor oil polyether component C with a comb-like structure for interfacial anchoring. The reaction molding process branch includes a terminal amino coupling reaction to generate polyether-branched block products at a temperature of 260°C. Up to 275 Furthermore, the melt reaction extrusion with a residence time of 30 to 50 seconds and the vacuum drying process to reduce the moisture content to less than 200 ppm, in the thermodynamic mechanism branch, cover the axial thermal hysteresis effect driven by the temperature drop rate difference at the bamboo joint, the directional migration of low surface energy component B to the surface enrichment, and the interfacial chemical pinning of component C to construct a flexible anchoring network. In the interfacial structure characteristics branch, the temperature drop rate of 1000 is described in detail. The surface tension gradient features with a surface tension reduction of 15% to 25% at / s, a viscosity ratio matching rule R with a value range of 1.05 to 1.20 to stabilize rheological properties, and a heterogeneous interface layer with a thickness of 150 nm to 300 nm at the bamboo joints and a thickness of 30 nm to 50 nm at the details.

[0042] Example 4: When the fiber axial hair undulation frequency is greater than Hz and spinning speed is at When operating at m / min, the composition is determined by the interface calibration procedure. The amount of additive was determined and the distribution of the interfacial anchoring structure was verified. The components were determined by perchloric acid titration. That is, bio-based polyamide The content of terminal amino groups in the resin The obtained measurement value mol / t, where the molar ratio of terminal amino groups to maleic anhydride groups is Under the conditions, the components were calculated. mass percentage in the composition for Online infrared spectroscopy monitoring was used in the screw reactive extrusion section. cm The characteristic peak of maleic anhydride cm The intensity of the characteristic peak of the amide bond and the conversion rate; when this conversion rate reaches... At that time, components With components Complete the interface pre-coupling.

[0043] To verify the driving mechanism of the non-uniform thermal field on the interface layer thickness, a liquid nitrogen quenching device was used to capture the temperature drop rate during the spinning process. The rate of melt flow and temperature drop at the bamboo joint is / s. The melt at the detailed part of the liquid nitrogen fracture was observed using a scanning electron microscope. At the bamboo-like joint, due to the effective reaction time... Extension, components With components A thickness of [thickness value missing] is formed at the phase interface. The transition layer, with a diameter of nm, exhibits an interwoven network structure, and its grayscale value lies between that of the two phases, indicating the composition... Guided chemical pinning networks will bind components Locked in the fiber surface layer, while in the detailed areas, the measured thickness of the interface layer is... The nm value and clear phase interface morphology indicate that the rapid cooling process inhibits the depth of chemical bonding; the axial heterogeneous interface distribution ensures that the composition meets the viscosity ratio requirements. for Performance constraints: ,in Viscosity ratio; For the composition in shear rate The apparent viscosity under the given conditions, the measured value is Pa·s; Components Under the same conditions, the measured viscosity is... Pa·s, when Less than At that time, the interfacial bonding strength at the bamboo node was lower than the peeling stress generated by the high-speed airflow, resulting in a high number of long hairs. per m, and when Greater than At that time, melt fracture causes an increase in surface roughness, which in turn causes the coefficient of friction to change from... Rise to And induces electrostatic accumulation in details, by increasing the viscosity ratio Controlled to Within the working window, the thickness of the flexible skin layer at the composition interface is matched with the axial mechanical strength of the fiber, and the coefficient of variation of the full yarn hairiness is... Stable at the following.

[0044] Example 5: In bio-based polyamide Resin is a component The initial relative viscosity fluctuation range is positive and negative. In the processing environment, in order to maximize the effective residence time within the reaction zone... In s to Within the dynamic window of s and to compensate for differences in equipment shear heat, a screw speed calibration process based on tracer particles is adopted, with an aspect ratio of s. In a co-rotating twin-screw extruder, tracer particles are added and the screw speed is set. exist rpm to The residence time was determined by measuring the actual melt flow curves at each speed, which varied in a stepwise manner between rpm. With rotational speed The corresponding model between them, based on the components The frequency of the feeding motor is adjusted based on the melt pressure sensor reading, so that the melt mass flow rate is related to the current rotation speed. Matching, thereby controlling the average residence time during the reactive extrusion process within s.

[0045] When the system processes a diameter of the above parameters, mm of bio-based polyamide When making slub yarn, the slub joints are utilized. s thermal hysteresis time-driven mass percentage Components Induced components at the interface Targeted enrichment occurs, and the composition is obtained through sampling and measurement. And the shear rate is Apparent viscosity under certain conditions for Pa·s, the composition was measured Apparent viscosity under the same conditions for Pa·s, the obtained viscosity ratio for The viscosity matching relationship satisfies the following mathematical formula: ,in The viscosity ratio is [value missing]. ; For the composition in shear rate Apparent viscosity under the given conditions, in Pa·s; Components The apparent viscosity, expressed in Pa·s, under the same test conditions, results in a thickness of... The interface layer at the bamboo joint has a thickness of nm. The interface layer at the nm level forms an axially asymmetric structure, which compensates for the lack of single-fiber binding force in the low-twist region, thus reducing the hairiness variation coefficient across the entire yarn length. Stable at The level.

[0046] Example 6: Under the condition that the melt flow field distribution in the distribution chamber shifts due to the replacement of the spinning assembly, in order to determine the residence time distribution under different shear processes and determine the composition... The interface reactivity was determined using a system calibration procedure based on the tracer response function, at an aspect ratio of [missing information]. Instantaneous injection at the feed end of a co-rotating twin-screw extruder g carbon black tracer particles are used to capture the concentration evolution signal of the tracer particles using an online photoelectric sensor installed at the head of the machine. The residence time distribution function is calculated based on the obtained concentration distribution curve. and average length of stay ,in, Let be the concentration distribution function. The variable is time, measured in seconds, when the screw speed... exist rpm to When adjusting the speed in a stepped manner within the rpm range, the relationship between residence time and speed is generated by fitting the data using the least squares method. This allows for adjustments to the speed to mitigate fluctuations in mass flow rate. The control deviation is limited to positive and negative Within s, make the components Maleic anhydride groups on the molecular chain and components The degree of interfacial branching of the terminal amino groups reached The design baseline value.

[0047] When the system faces fiber diameters of... mm to When producing slub yarn varieties with periodic jumps between mm, in order to determine the driving effect of the temperature drop rate gradient on the interface layer thickness and eliminate physical defects in the forming process, a cooling process preset procedure based on an unsteady-state thermal conduction model is executed. Infrared sensors are used to monitor the temperature evolution of the fiber surface after leaving the spinneret, and the thermal hysteresis time of each section is calculated according to the following heat transfer formula: ,in The time lag is expressed in seconds (s). The density of the composition is expressed in kg / m³. ; Specific heat capacity, expressed in J / (kg•K); The diameter is the fiber diameter, in meters (m). Melting temperature, in units of ; The temperature of the cooling air is expressed in units of . ; The critical temperature of the reaction, in units of... ; The surface heat transfer coefficient is expressed in W / (m²). ·K), the diameter is calculated to be mm bamboo joint corresponding to for s, and the diameter is mm details correspond for s, this The kinetic window difference drives the components A thickness of [thickness] is constructed at the bamboo joint area. The interface layer is nm thick, while maintaining the details. The interface layer thickness of nm makes the viscosity ratio across the entire yarn length range... Deviation less than And maintain the coefficient of variation of feathers exist The level.

[0048] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn, characterized in that, include: Component B, by weight percentage, is 2.5% to 6.0%, and Component B is bio-based polyamide 1010 resin; 0.5% to 2.0% of component C, which is maleic anhydride-grafted castor oil polyether; And the balance of component A, which is a bio-based polyamide 56 resin with a relative viscosity of 2.4 to 2.8; Among them, the weight-average molecular weight of component C is 3500 g / mol to 5500 g / mol, and the maleic anhydride grafting rate of component C is 0.8% to 1.5%; The melting point of component B is 15 degrees lower than that of component A. Up to 25 ; The composition was extruded via a co-rotating twin-screw extruder at 260°C. Up to 275 The melt reaction extrusion is carried out within the temperature range, so that component C and the terminal amino group of component A undergo a coupling reaction to generate a polyamide 56 block product containing castor oil polyether branches. During the spinning and cooling process, the composition corresponds to a temperature drop rate difference of 25% to 40% caused by the difference in axial diameter of the slub yarn. The polyamide 56 block product migrates to the fiber surface and undergoes interfacial bonding with the component β. The thickness of the interfacial layer formed at the slub of the slub yarn is 150 nm to 300 nm, and the thickness of the interfacial layer formed at the details of the slub yarn is 30 nm to 50 nm.

2. The bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn according to claim 1, characterized in that, The melting point of component B is 200°C. Up to 205 Component B at 230 The melt index under a load of 2.16 kg is 15 g / 10 min to 25 g / 10 min; the terminal amino content of component A is 45 mol / t to 55 mol / t; and the composition is suitable for use at a cooling rate of 1000 °C. The thickness of the interface layer formed under conditions of / s is similar to that formed at a temperature drop rate of 2000. The ratio of the thickness of the interface layer formed under the condition of / s is 3 to 10.

3. The bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn according to claim 1, characterized in that, The composition satisfies the following viscosity matching rule: ,in, This refers to the viscosity ratio, with values ​​ranging from 1.05 to 1.

20. For the composition at 260 Apparent viscosity under a shear rate of 1000 / s; Let be the apparent viscosity of component A under the same test conditions.

4. The bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn according to claim 1, characterized in that, Component C at 100 The kinematic viscosity is 400 mm² / s to 600 mm² / s; the castor oil polyether segment in component propylene contains 20 to 40 repeating ethylene oxide units.

5. The bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn according to claim 1, characterized in that, The composition is prepared by the following steps: Step 1, components A, B and C are respectively heated at 105 °C. Up to 115 The components are vacuum dried for 8 to 12 hours until the moisture content of each component is below 200 ppm. In step two, the dried components A, B, and C are fed into a high-speed mixer for dry mixing, so that component C coats the surface of component A. In step three, the mixed raw materials are added to a co-rotating twin-screw extruder and extruded at 260°C. Up to 275 The mixture is then subjected to a melt reaction and extrusion.

6. The bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn according to claim 5, characterized in that, In step three, the screw length-to-diameter ratio of the co-rotating twin-screw extruder is 44:1, the screw speed is set to 300 rpm to 500 rpm, and the residence time of the melt in the reaction zone of the twin-screw extruder is 30 seconds to 50 seconds.

7. The bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn according to claim 1, characterized in that, Component A contains 0.05% to 0.15% by mass of a terminal amino modifier, which is terephthalic acid, used to control the molar ratio of the terminal amino group of component A to the maleic anhydride group of component C at 1:0.8 to 1:1.

2.

8. The bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn according to claim 1, characterized in that, Component C has a comb-like structure, and its branches are castor oil polyether segments with oleophilic properties, which are used to provide internal lubrication in the molten state and reduce the interfacial tension between component B and component A.

9. The bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn according to claim 1, characterized in that, The composition exhibits the following surface tension characteristics at different temperature drop rates: The composition at a temperature drop rate of 1000... The surface tension at / s is greater than that at a temperature decreasing rate of 2000. The surface tension is 15% to 25% lower at / s.

10. The bio-based polyamide modified raw material composition for improving the surface hair distribution of slub yarn according to claim 1, characterized in that, The composition is used to manufacture bio-based polyamide fibers.

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