Table of Content

10 May 2023, Volume 31 Issue 3

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Structure optimization of traditional SK type and new static mixers

CHEN Xifeng, CHEN Ye

2023, 31(3):  1-11. 

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In order to improve the synthetic quality of polyacrylonitrile fibers, starting from improving the mixing uniformity of the three-strand material of synthetic polyacrylonitrile, the numerical calculation method of multiphase flow field is carried out by using CFD technology, the influence of component structure parameters and component quantity of SK type static mixer on the uniformity of the three-strand material premix in the mixer tube is discussed, and the corresponding pressure drop changes are analyzed. The results show that when the width of the mixing element is D=110 mm, the aspect ratio is L/D=1, and the component torsional angle is α=270°, the mixing efficiency is the highest. And the new static mixer is numerically simulated based on the optimized mixing element parameters, with the purpose of achieving ideal mixing uniformity, and the total length of the new mixer when meeting the requirements is about 1/2 of the length of the traditional SK static mixer. The mixing efficiency of the new static mixer is greatly improved compared to that of the traditional SK static mixer, but the pressure drop loss is also large.

Design of the secondary fractal spiral spinning needle and its influence on the electric field strength

LIU Yanbo, ZHOU Cong, HAO Ming, HU Xiaodong, YANG Bo

2023, 31(3):  12-20. 

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The electrospinning technology is a method to stretch polymer fluids for fabricating nanofibers with diameters of tens to thousands of nanometers under the electrostatic field force, which is simple, widely applicable, and the most promising in the industrialization of nanofibers. At present, the preparation of large-scale electrospun nanofibers includes needle type and needleless type. Compared with the needle electrospinning technology, the needleless electrospinning technology has the advantages of zero needle clogging problem, easy cleaning and significantly higher production efficiency. However, the current needleless electrospinning technology used for the industrial preparation of nanofibers requires a high spinning voltage, which may break down the air, resulting in  great safety hazards, high energy consumption, wide diameter distribution and poor quality of the fibers. The fractal spiral has a self-similarity characteristic, which can improve the uniformity of the field strength of the spinning electrode based on the spiral curve in the fractal structure. The multi-spinning site characteristics of the fractal curve can improve the electric field strength and production efficiency of the electrode, so as to save energy and improve the fiber quality. Firstly, we start with the cylindrical spiral, and obtain the parametric equation of quadratic fractal spiral through space coordinate transformation, establishing the mathematical model of quadratic fractal spirals. Then, the mechanical model of the spinning unit of the fractal spinning needle is established by using the quadratic fractal spiral parameter equation, and multiple spinning units are combined to form an array of spinning needle. Finally, we change the following variables in turn while keeping other variables constant: primary radius, primary pitch, secondary radius, number of secondary disturbing turns and wire radius. By using finite element analysis software, the field strength of the spiral spinning needle with quadratic fractal structure is analyzed and the optimal structure is obtained. It is found that the electric field strength and CV value increase with the increase of the primary radius. The increase of the primary pitch can increase the electric field strength but decrease the CV value. The increase of the secondary radius, the number of secondary perturbations turns and the radius of the wire can lead to a decrease in the field strength value and has few effects on the CV value. Combined with the actual situation, the optimal parameters of fractal structure are determined as follows: primary radius of 80 mm, primary pitch of 60 mm, secondary radius of 10 mm, number of secondary disturbance turns of 40 and wire radius of 0.2 mm. The average electric field strength is 31.8 kV/cm and the CV value of the field strength is 7.53%. The results show that the structure of the spinning needle can effectively reduce the voltage required for spinning, and the energy consumption is low. Moreover, the uniform field intensity will make the electrospun nanofibers evenly distributed, which is of significance to be referred for the actual industrial production of nanofibers.

Design and analysis of automatic grabbing device for cocoons without end  in supplier of correct end cocoons#br#

YANG Xiaolong, LI Sheng, JIANG Wenbin

2023, 31(3):  21-26. 

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In order to solve the problem that there are cocoons without end in supplier of correct end cocoons during silk reeling and that the cocoons without end are grabbed manually, an automatic grabbing device for cocoons without end in supplier of correct end cocoons is designed. The transmission part transmits the power to the supplier of correct end cocoons and the transverse sliding rail mechanism through two transmission routes by the deceleration motor. The motion characteristics of the slider-crank mechanism and the linear differential doubling mechanism of gear and rack contained in the transverse sliding rail mechanism are analyzed in detail, and the optimal grabbing node is determined by calculation. Finally, the end-grabbing mechanism is introduced, and the time rhythm of laying the cocoons without end and reset of the device is planned. The analysis shows that the structure of the automatic grabbing device for cocoons without end in supplier of correct end cocoons is reasonable and feasible, which provides a new idea for the treatment of cocoons without end in supplier of correct end cocoons.

Topology optimization design and fatigue analysis of the warp tension regulating mechanism

ZHAO Quanpenga, b, YANG Jianchenga, b, c, LIU Yanzhea, b, HUANG Ziwena, b

2023, 31(3):  27-35. 

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In order to improve the dynamic compensation ability of the warp tension regulating mechanism and to meet the needs of high-speed weaving of three-dimensional spacer rapier loom, the variable stiffness pneumatic tendons which can absorb stress were introduced as the prime mover. A new type of warp tension regulating mechanism was designed, and its static characteristics and the first six natural frequencies were obtained by static and modal analysis with finite element technique. Then the topology of the mechanism was optimized by the variable density method, and the structure was optimized in SW according to the obtained results. The simulation results show that the weight loss is 13.32%, and the static and dynamic properties of the mechanism, such as stress, strain, and natural frequency, are greatly improved after topology optimization. Moreover, the fatigue life of the mechanism can reach 17.91 years, which meets the need of loom service life. At last, a comparative experiment was carried out on a series of VSI sample looms to analyze the tension sampling curves before and after the optimization. It is found that the tension fluctuation is more stable after the optimization and the dynamic characteristics of the mechanism are effectively improved after the topology optimization.

Morphological structure regulation mechanism of the chenille yarn and its spinning process design

LIN Wei, XUE Yuan, JIN Shulan, LUO Jun, LIU Qunhao

2023, 31(3):  36-44. 

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The morphological and structural parameters of the chenille yarn include the linear density of the chenille yarn, the arrangement density of the decorative yarn, the diameter of the chenille yarn and the twist of the chenille yarn. In order to explore the regulation mechanism of the chenille yarn′s morphological structure, the linear speed of the former roller, the winding speed of the decorative yarn and the width of the spacer were taken as design parameters. Based on the chenille spinning machine, the spinning technology was studied to change the arrangement density and the width of chenille yarn ornaments, and to realize the control of chenille yarn shape structure. The chenille yarn of different specifications is designed and spun. The results show that by changing the linear speed of the front roller and the winding speed of the decorative yarn, the arrangement density of the decorative yarn can be continuously changed when the same chenille yarn is spun, showing different morphological structures. Among them, when the linear speed of the front roller is changed, the arrangement density ratio of the decorative yarn in the same chenille yarn can reach up to 3.3 times, and when the winding speed of the decorative yarn is changed, the arrangement density ratio of the decorative yarn in the same chenille yarn can reach 4 times. By changing the width of the spacer, chenille yarns of different diameters and widths can be spun. The regulation mechanism of chenille yarn's morphological and structural parameters was studied, and the spinning process of chenille yarn was broadened to improve the market competitiveness of chenille products.

Development and application of spinning scheduling information system based on the order

JIN Haiweia, DAI Ninga, b, SHEN Chunya, SHI Weimina, HU Xudonga

2023, 31(3):  45-52. 

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 In view of the current pain point including complex and diverse processing procedures in spinning workshops, blocking information exchange between production departments, insufficient delivery capacity of orders on schedule, and unreasonable allocation of human and material resources, this paper, taking the actual production workshop of the enterprise as the object, carries out the production scheduling process design and production order analysis based on the analysis of the production status. Meanwhile, the micro-service architecture is used to design a reasonable spinning and production scheduling information system. The application results show that the system provides a scientific and efficient management mode for order-oriented production planning and workshop operation execution, and ensures the normal production progress and on-time delivery of yarn orders, thus laying a foundation for the subsequent informatization development of enterprises.

Construction of the workshop model of the wrapping and texturing integrated machine based on digital twin

SUN Changmina, SHEN Chunya, HU Xudonga, DAI Ninga, b

2023, 31(3):  53-62. 

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China is a big textile country. Although the textile industry is an important pillar industry in China and has achieved rapid growth after decades of reform and opening up, backward technology is still an urgent problem to be solved. At present, most of the digital workshops in the textile industry only display the real-time production data of the workshops, and cannot realize the real-time visual monitoring and remote operation and maintenance of the workshops. This kind of workshop has the problems of incomplete information interaction and low degree of visualization, and also produces the “black box” operation, which leads to the insufficient monitoring of the execution information of the underlying workshop by the management personnel. With the emergence of the digital twin technology, the precise real-time mapping of physical entities is realized by constructing a multi-dimensional high-fidelity twin model, which provides an effective solution for the digitization and intelligence of the workshop.
In order to promote the intelligentization and digitization of the traditional wrapping and texturing integrated machine workshop, we study the construction method of the wrapping and texturing integrated machine workshop model based on digital twin. Starting from the digital twin system architecture, we construct the twin model from the four angles of the wrapping and texturing integrated machine, human, yarn and environment. We construct the twin model in three steps. Firstly, we construct the model according to the three dimensions of geometry, physics and production behavior. Secondly, we collect the workshop data. Finally, we map the data accurately to the model in real time. We establish the tree structure chain that binds the geometric relationship and assembly relationship of the model from the geometric dimension, achieve a realistic effect by setting the physical properties and motion state of the object from the physical dimension, and mainly describe the activities of the elastic clad yarn produced by the wrapping and texturing integrated machine from the production behavior dimension. The mapping is mainly divided into position mapping and production behavior mapping. The position mapping changes the object coordinates at the next moment through the coordinate transformation matrix and the object coordinates at the previous moment. The production behavior mapping first defines the correlation matrix according to the processing time and the fact whether the process event is triggered, then determines whether a fault or an abnormal event occurs, and performs integrated analysis according to the classification of event results. Finally, the decision results are fed back to the workshop personnel through the GUI panel and the workshop indicator to achieve the virtual and real linkage. In this paper, the digital twin technology is used to establish the twin workshop model. Compared with the traditional model, it obtains the physical entity data in real time and evolves with the physical entity in real time, so that it is consistent with the physical entity in the whole life cycle of the product. With the wrapping and texturing integrated machine workshop of an enterprise as an example, the effectiveness of the twin model construction method is verified, and the workshop visualization ability, virtual and real interaction ability and production efficiency are improved. 
In this paper, the architecture, construction method and mapping mechanism of the twin model of the workshop are studied, and the virtual simulation of the workshop and the collection and storage of virtual and real data are realized. In the future, the intelligent algorithm will be further studied for fault diagnosis, quality prediction, intelligent decision-making and optimization of production process.


Effects of the elastic linkage on the front dead center position of the parallel beating-up mechanism

LIU Yanzhea, b, c, YANG Jianchenga, b, c, HUANG Ziwena, b, c, ZHAO Quanpeng, LIU Jian

2023, 31(3):  63-69. 

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The double-rapier loom is a kind of weaving machine that is mainly used for weaving spacer fabrics. The research on double-layer rapier looms in China started in the middle and late 1980s. The domestic double-rapier looms have been restricted by the limited technical level, the low reliability of the equipment, and the low speed. The general weaving efficiency is only 80-85 weft/min, and the industrial production has not been realized. The relevant foreign products can reach 180 weft/min. Therefore, it is of great significance to study the dynamic characteristics of the beating-up mechanism for speeding up the high-speed process of domestic spacer double-rapier looms.
With the increase of the loom speed, the connecting rod components in the parallel beating-up mechanism with a conjugate cam and four connecting rods will deform more under the action of the inertial load, resulting in deviation between the reed front dead center position and the ideal position, and affecting the beating-up accuracy. To solve this problem, we adopted the method of combining virtual simulation and experiment to study the mechanism. First, we discretized the link components that are regarded as elastomers based on ANSYS software, and jointly used ADAMS software to establish the rigid flexible coupling dynamic model of the parallel beating-up mechanism under the flexible link. The model was simulated every 20 r/min as a data point within the range of 80-300 r/min of the cam speed, modal analysis of the driven link mechanism was carried out, and the influence of different cam speeds on the reed front dead center position was investigated. Then, nodular cast iron, cast aluminum, medium carbon structural steel and alloy structural steel were selected as the connecting rod materials. At the same speed, the mechanism model was simulated to explore the influence of different materials of the elastic connecting rod on the dead center position of reed. At the same time, the experimental platform was built, and the laser displacement sensor was used to measure the deviation between the actual front dead center position and the theoretical position of the reed under different cam speeds, so as to verify the conclusions of the simulation on the impact of the cam speed on the reed front dead center position. The results show that there is overswing phenomenon in the process of the reed beating-up, and the reed dynamic response of the rigid flexible coupling model under the condition of elastic linkage can better reflect the real motion of the beating-up mechanism. The simulation and experimental results show that the overall trend of reed front dead center position deviation is consistent with the change of cam speed. It can be seen that the influence of cam speed on reed front dead center position is nonlinear, and the reed front dead center position is stable and the deviation value is small when the cam speed is within 180 r/min. Based on the simulation analysis, it is concluded that the selection of materials with greater stiffness than elastic connecting rod components is helpful to reduce the reed front dead center position deviation.
The research results have a certain guiding significance for the actual engineering practice, and provide a reference for the design and optimization of high-speed conjugate cams and four-bar parallel beating-up mechanisms.


Prediction of loom warp-out time based on LSTM recurrent neural network

XU Kaixina, DAI Ninga, b, RU Xina, HU Xudonga

2023, 31(3):  70-80. 

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Due to the different production conditions and impact parameters, looms have great differences in the actual weaving efficiency and loom warp-out times from each other. Aiming to solve the problem that the deviation between the theoretical calculation value and the actual value of loom warp-out time is too large when calculating it by using the pre-set static parameters of planned production, a loom warp-out time prediction method based on LSTM (Long Short Term Memory)  recurrent neural network is proposed. Based on the analysis of the factors affecting the loom warp-out time from three aspects: the warp and weft stop of the loom, the working efficiency of personnel and the variety of cloth processed, a data set of loom production with time series characteristics is constructed. The prediction of the model in the whole life cycle of the weaving axis is dynamically adjusted by setting the time schedule coefficient, and the performance of the model is optimized from the two aspects of loss degree and training time. Finally, eight groups of experimental data are used to verify the reliability of the model. The experimental results show that when it is 30 hours to 6 hours before the warp-out time of machine prediction, the average error range between the predicted value of the model and the actual value is 0.84 h to 1.52 h, which meets the requirements of actual production.

Production scheduling model of garment sewing workshop with learning and forgetting effects#br#

DONG Pingjun, YU Jian’an

2023, 31(3):  81-91. 

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 With the deep integration of cutting-edge technologies, such as Internet of Things, artificial intelligence and 5G and manufacturing, the fourth industrial revolution, represented by intelligent manufacturing, is taking place. There is no exceptions of traditionally labor-intensive textile and garment industry, in which most value chain sections such as spinning and weaving are undergoing or have undergone profound changes. Nevertheless, in the sewing link of garment manufacturing and production, on the one hand, most manufacturers are forced by market demand to increasingly turn to the production mode of small batch and short delivery cycle; on the other hand, the sewing link itself involves many processes and changes quickly. In the foreseeable future, it is difficult for automatic machines to meet this highly flexible production environment, and manual density will remain an important feature of garment sewing production. At the same time, China's textile and garment industry is in a period of transfer and change, with rising labor costs and high turnover of front-line production employees, resulting in more complexity and uncertainty. In order to adapt to the general trend of manufacturing transformation and upgrading, and adapt to the complexity of garment sewing production, it is one of the potential directions to study a new management scheduling method that takes into account workers' cognitive and learning differences.
We proposed a hybrid flow batch scheduling model including employees' learning and forgetting effects for garment sewing workshops. We used minimizing makespan and minimizing idle mean square error as the objective function, and selected the non-dominated genetic algorithm as the solution tool, aiming to realize "worker-process-station" fine-grained scheduling optimization. According to the model, we carried out an algorithm simulation experiment on a real garment factory data, selected the appropriate batch size as the experimental parameter, and compared two kinds of scheduling optimization models with and without learning and forgetting effects. The simulation results show that model considering the learning and forgetting effects is more suitable for the production environment under heterogeneous scenarios of workers than not considering, which verifies the effectiveness of the model and algorithm.
We introduce the worker learning and forgetting factor matrix to optimize scheduling design for increasingly uncertain production environment. As for how to reasonably determine each worker's learning and forgetting factors,  we can consider using the real-time big data of the MES system, ERP system and the Internet of Things system of the garment factory in the next step to build a dynamic model to fit and calculate factors such as the learning and forgetting rate of "employee-process-station", so as to achieve a real-time dynamic executable scheduling scheme


Preparation and properties of AgNWs-PVDF air-jet- electrospinning microfiber

Xiong Tiantian, Li Lijun, Zou Hantao, Nie Fushan

2023, 31(3):  92-101. 

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In order to improve the spinning rate and fiber strength of electrospinning, AgNWs-PVDF nanofiber membranes were prepared by coaxial electrospinning needle combined with high-speed airflow assisted electrospinning.The microstructure, filtration, strength and antibacterial properties of nanofibers were studied by SEM, permeability, filtration, mechanical properties, antibacterial properties, porosity and pore size distribution.The results showed that after adding AgNWs, the average diameter of 0.5% AgNWs-PVDF air-jet-electrospinning nanofiber membranes was the lowest, up to 73.85 nm, while the average pore size and breaking elongation of the nanofiber membranes decreased. The 1% AgNWs-PVDF air-jet-electrospinning membrane had the strongest breaking strength, reaching 6.52 MPa. With the increase of the AgNWs content, the hydrophilicity of the air-jet-electrospinning membrane increased, the air permeability decreased, and the filtration efficiency increased.The 2% 
AgNWs-PVDF air-jet-electrospinning fiber membrane had the best antibacterial effect, and the diameters of the inhibition zone against Escherichia coli and Staphylococcus aureus were 26.23 mm and 26.89 mm, respectively.


Application of photocatalytic titanium dioxide fibers in carbon dioxide reduction

YANG Ting, ZHANG Yeke, ZHOU Wenlong, LIU Yuqing

2023, 31(3):  102-112. 

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Titanium dioxide (TiO2) is an important inorganic material with stable chemical properties, low toxicity and biocompatibility. In particular, its photochemical properties have played a good catalytic effect in hydrogen evolution, wastewater degradation and waste gas treatment. In recent years, with the increase of carbon emissions, the application of TiO2-based photocatalytic materials in CO2 reduction has been widely studied. Compared with nanoparticles, TiO2 materials with nanofiber structure stand out due to their efficient photogenerated electron-hole separation behavior and excellent catalytic stability. Therefore, the exploration of the forming process and material compounding of TiO2 is constantly advancing its carbon reduction efficiency to the expected industrial application.
TiO2 can be designed as a nanofiber structure, which extends the reaction path of photogenerated electrons by virtue of its closely connected interworking structure, so as to improve the rapid recombination of electron holes in nanoparticles. Hydrothermal method is a common method to prepare nanofibers from inorganic metals, and TiO2 nanofibers with different crystal forms and special structures can be produced by adjusting the heating time and temperature during the reaction. Electric field can stretch the spinning solution fluid in the electrospinning method. TiO2 nanofibers can be prepared with larger length with the help of easily removed polymer spinning carrier. Likewise, different catalytic aids can be doped in the TiO2 structure. Nanofibers with smaller diameter can be grown on mesoporous carriers by vapor phase growth method, and the catalyst is uniformly dispersed. In addition, supercritical synthesis, anodic oxidation and laser ablation can be used to prepare TiO2 nanofibers.
The wide band gap of TiO2 makes it have a short absorption wavelength, which makes it difficult to use sunlight efficiently. In order to further improve the photocatalytic performance, compounding or doping on TiO2 nanofibers (heterojunction) can reduce the band gap width and improve the photon absorption rate while ensuring the catalytic efficiency. Common metal doping materials include gold, platinum, copper, etc., and the doping of non-metallic elements such as carbon, nitrogen and sulfur also helps to increase the light absorption wavelength of TiO2.
In summary, the photocatalytic effect of TiO2 with nanofiber structure in CO2 reduction has been widely studied. The analysis of its catalytic mechanism often focuses on the transformation of TiO2 crystal form, the rate of photogenerated electron movement and the movement effect of various particles. However, the application of TiO2 nanofibers in carbon reduction is still in the laboratory stage. How to comprehensively design a structure to use in the industrialized waste gas treatment process is still one of the problems that researchers need to solve. At present, the widely used electrospinning technology can design multiple elements into the microstructure of TiO2-based photocatalytic materials. Combined with the flexibility and integration of nanofibers, the catalytic efficiency of CO2 reduction can be further improved from both material and structure.


Preparation and properties of zinc oxide antibacterial polyester

ZHANG Rui, LI Yuanyuan, ZHOU Panfei, ZHANG Shunhua

2023, 31(3):  113-120. 

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With the development of economy and the improvement of living standards, people have more and more requirements on the functionality of textiles, and the concept of health and safety has become a common understanding. Polyethylene terephthalate (PET) has good spunability and mechanical properties, and is widely used in household textile, medical textile, industrial textile and other fields. Therefore, more and polyester has been paid to the antibacterial function of polyester.
 For the more convenient and effective one-step preparation of antibacterial modified polyester with better dispersion effect of antibacterial agent, nano-zno was selected as the antibacterial agent in this paper, and nano-zno was dispersed in ethylene glycol (EG) solution to make ZnO-EG dispersion solution. Then the monomer purified terephthalic acid (PTA), EG and ZnO-EG dispersion were esterified and condensed by in situ polymerization to obtain antimicrobial modified polyester. The polymerization process of antibacterial modified polyester was analyzed, and the particle size distribution of ZnO-EG dispersion was characterized by laser particle size analyzer. The slice morphology and melting point of the antibacterial modified polyester were analyzed by polarizing microscope and DSC, and the color value, characteristic viscosity, carboxyl terminal content, diethylene glycol content and antibacterial properties of the antibacterial modified polyester were determined. The results show that the particle size of the nano-zno dispersion prepared by wet grinding is obviously smaller than that prepared by magnetic stirring, and with the increase of the wet grinding time, the particle size of the dispersion decreases first and then increases. When the ZnO mass fraction of the antibacterial polyester is 0.5% and the intrinsic viscosity is 0.687 dL/g, the nano-zno antibacterial agents do not agglomerate in the polyester and form agglomerative particles, which are uniformly dispersed in the polyester slices. With the addition of nano-zno antibacterial agents, the color value of the antibacterial polyester tends to bright yellow-green, and the melting point moves to high temperature. The antibacterial polyester has obvious antibacterial effect on Escherichia coli, Staphylococcus aureus and Candida albicans, with the inhibition rates being 92%, 99% and 78%, respectively.
In this paper, antibacterial modified polyester is prepared by in-situ polymerization, and the particle size distribution of ZnO-EG dispersion and the polymerization process of antibacterial modified polyester are studied, which provides a new idea for the optimization of synthesis process of antibacterial modified polyester. The quality of the antibacterial modified polyester is analyzed, which provides some reference for the future application in the field of plastic fibers.


Preparation and properties of SBS/CNTs elastic conductive composite fiber

LI Dongliang, LIU Huiying, LI Lele, SUN Baojie, JIANG Liang, ZHOU Yanfen, CHEN Shaojuan, MA Jianwei

2023, 31(3):  121-127. 

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In recent years, with the progress of science and technology, wearable electronic products have been used more and more in portable medical monitoring devices, electronic skin, portable electronic devices and other fields. Strain sensors, as the core components of intelligent wearable devices, have received extensive attention. Traditional strain sensors based on metal and semiconductor materials have poor extensibility and unstable conductivity, which limits their use in the intelligent wearable field. Conductive polymer composite fiber, with the advantages of being easy to bend, can be attached to skin, and can be braided, so its application in strain sensors has been rapidly developed.
In order to prepare flexible strain sensors with good tensile property, the SBS/CNTs elastic conductive composite fiber was prepared by wet spinning, using polystyrene butadiene styrene triblock thermoplastic elastomer (SBS) with good tensile property as the matrix and carbon nanotubes (CNTs) with high conductivity, good mechanical properties and flexibility as the conductive filler. The influence of the mass ratio of CNTs with two different aspect ratios on the morphology, mechanical properties, electrical conductivity and tensile resistance response of SBS/CNTs elastic conductive composite fibers were studied. The results showed that the cross section of SBS/CNTs elastic conductive composite fiber was bean-shaped, and porous structure appeared near the fiber center due to solvent exchange during wet spinning. When the ratio of long CNTs (10~30 µm) to short CNTs (0.5~2.0 µm) was 4:1, the conductivity of SBS/CNTs elastic conductive composite fiber was the highest (0.04065 S/m). The maximum inductive strain of the strain sensor based on this fiber was 70.2%, and it had good sensitivity and stability. The strain sensor based on SBS/CNTs elastic conductive composite fiber showed good response behavior in monitoring various human body activities including the knee, wrist, finger and elbow.
Although the conductive polymer composite fiber based strain sensor has more excellent tensile properties, there are still some problems to be solved. For example, carbon nanotubes and other nano sized conductive fillers are easy to agglomerate in the polymer matrix. How to improve their dispersion by surface modification or adding compatibilizers, and how to improve their interfacial bonding with the polymer matrix are problems to be solved. In addition, the performance of the fiber is affected not only by the material performance, but also by the spinning process parameters. Through the optimization of the spinning process, it is expected to prepare conductive composite fibers with better performance. The solution of these problems will better promote the practical application of flexible strain sensors.


Preparation and properties of medical stone/polylactic acid blends for the fabrication of melt-blown nonwoven

LIU Peng, YU Bin, SUN Hui, YANG Xiaodong

2023, 31(3):  128-136. 

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In order to explore the structure and processibility of medical stone/polylactic acid blends of melt-blown nonwoven, the methyltriethoxysilane (MTES) was first used to modify the surface of medical stone (MS) for the improvement of the interfacial interaction between MS and polylactic acid (PLA). Then MS was mixed with PLA by the melt blending method. The cross-section morphology, crystal structure, thermal stability and mechanical properties of the blends were characterized and analyzed. The results showed that MTES-MS had good interfacial compatibility with PLA matrix. The addition of MTES-MS had little effect on the glass transition temperature and crystallization structure of PLA. However, compared with pure PLA, the crystallinity and thermal stability of MTES-MS/PLA blends increased. With the increasing of the content of MTES-MS, under the same temperature condition, the melt flow rate (MFR) of the blends decreased and the fluidity became worse, but still met the spinnability requirements of melt-blown processing. The longitudinal tensile strength and elongation at break of MTES-MS/ PLA first increased and then decreased when MTES-MS was added. When the content of MTES-MS was 7%, the mechanical properties of the blends were optimal. Compared with pure PLA, the longitudinal tensile strength of the blends increased by 76.17% and the longitudinal elongation at break increased by 70.79%.

Influence of particle size of hollow silica on thermal conductivity and softness of polyacrylonitrile fiber membranes

ZHOU Chengliang, SI Yinsong, FU Yaqin

2023, 31(3):  137-144. 

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In order to explore the influence of the particle size of hollow silica (SiO2) in the thermal insulation filler on the thermal conductivity and softness of the fiber membrane prepared by electrospinning, hollow SiO2 microspheres with different particle sizes were designed and prepared. Polyacrylonitrile (PAN) fiber membranes were filled with hollow SiO2 to prepare hollow SiO2 microspheres/polyacrylonitrile (PAN) composite fiber membranes by uniaxial electrospinning. Scanning electron microscope, transmission electron microscope, thermal constant analyzer and other instruments were used to observe, test and analyze the morphology of hollow SiO2 microspheres, the morphology, thermal conductivity and softness of composite fiber membranes. The results show that the self-made hollow SiO2 microspheres have uniform particle size and regular morphology, and there is good dispersibility in the fibers. Besides, adding a small amount of hollow SiO2 microspheres can significantly improve the thermal insulation performance of the composite fiber membrane. Therefore, reducing the particle size is beneficial to increase the thermal insulation performance of the composite fiber membrane. Compared with the thermal conductivity of the pure polyacrylonitrile fiber membrane of 0.0480 W/(m·K), the thermal conductivity of the composite fiber membrane filled with 130 nm hollow SiO2 microspheres is 0.0359 W/(m·K), which is reduced by 25%. And the hollow SiO2 microspheres have a small particle size, which can make the composite fiber membrane maintain higher flexibility.

Preparation of polyvinyl alcohol/sodium alginate drug-loaded composite hydrogel and its antibacterial properties

2023, 31(3):  145-157. 

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In recent years, people have paid increasing attention to wound healing, and medical dressings have developed rapidly. Wound dressings can act as a skin protective barrier to prevent wound infection, quickly absorb wound exudate, and guide human tissue regeneration. The ideal dressing material should not only absorb the excess exudation of the wound, but also keep the wound in a proper moist state, effectively avoid the dry necrosis of the wound tissue and prevent secondary infection. Hydrogels, which are a hydrophilic cross-linked polymer network, can maintain a large amount of water by expansion, and perfectly mimic the natural structure of the tissue microenvironment. Due to its porous structure, biodegradability, growth factor incorporation ability and controlled release ability, it is a promising dressing material. In particular, hydrogels can be loaded with antimicrobial materials such as antibiotics, nanoparticles, and natural products to avoid contact with external bacteria and to effectively prevent cross-infection and improve the healing process.
From the perspective of biosafety and anti-infection, we use polyvinyl alcohol (PVA) and sodium alginate (SA) as raw materials to prepare a PVA/SA composite hydrogel with semi-interpenetrating network structure (SIPN) by a green and simple method, namely cyclic freezing-thawing method, to improve the biological characteristics of PVA and the brittleness of SA, and use it as a carrier to better carry Vancomycin hydrochloride (VAN), aiming to achieve a new composite material with excellent biocompatibility, good mechanical properties and antibacterial effect. The morphology and structure were characterized by scanning electron microscope (SEM), infrared spectrometer (FT-IR) and X-ray powder diffractometer (XRD). The swelling degrees, porosities and mechanical properties of PVA/SA@VAN drug-loaded composite hydrogels were analyzed, and their antibacterial properties were explored. The results showed that the PVA/SA@VAN drug-loaded composite hydrogels all showed a three-dimensional porous structure, with uniform pore distribution and a porosity of more than 80%. They swelled rapidly in phosphate buffer solution without dissolution, and the swelling degree could reach 1338%. They had strong water absorption and swelling ability and good mechanical properties. Antibacterial experiments showed that the PVA/SA@VAN drug-loaded composite hydrogel had significant antibacterial effect on Staphylococcus aureus. The results of this study provide a basis for the application of drug-loaded composite hydrogels in wound dressings.
At present, the demand for antibacterial wound dressings that control infection and prevent microbial invasion by releasing fungicides is gradually increasing. The antibacterial composite hydrogel wound dressing prepared in this paper can be used as a short-term dressing candidate for acute wounds. The research results can provide reference for the research of hydrogel wound dressings.


Effects of activating oiling agents and oiling technology on the properties of polyester high strength fibers

SHI Qiang, SHI Jiaoxue, ZHENG Xiong, ZHANG Xuzhen

2023, 31(3):  155-162. 

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The activated polyester industrial yarn is a new type of industrial yarn. It can form good adhesion with rubber, PVC and other polymer matrices due to the reactive activating oiling agent attached to its surface. The original composite molding process of "spinning oiling-predipping-RFL dipping-rubber compounding" can be simplified into "activated oiling-RFL dipping-rubber compounding" because of the activated filaments. This technology can prepare polyester fabric reinforced composites with light weight, deformability, high strength, high modulus and good dimensional stability, which can be widely used in automotive industry, construction engineering and other fields.
Activating oil agents play an important role in the preparation of activated polyester industrial yarns. As an important auxiliary agent to endow surface activity of polyester industrial yarns, the activating oiling agent is usually dynamically oiled through nozzles or tankers after fiber preparation. When the activating oil agent contains a humidity sensitive group, it is generally necessary to dry the oiled fibers in order to prevent excess water molecules from interfering the activation reaction after the unsealing section of the activating oiling agent. At present, there is little research on the influence of the activating oiling agent and drying treatment on the original properties of polyester industrial yarns. For this reason, three kinds of common polyester industrial yarns (general high strength GHT, high modulus low shrinkage HMLS and high strength ultra-low shrinkage SLS) were chosen as the raw materials. The yarns were treated with activating oil agents, and dried at room temperature or 75 ℃. The effects of activating oil agents and drying conditions on the linear density, mechanical properties, thermal shrinkage properties, sonic orientation and crystallinity of polyester industrial yarns were thus investigated. The experimental results show that the linear density and crystallinity of the three polyester industrial yarns increase slightly after drying treatment, while the mechanical properties, thermal shrinkage properties, sonic orientation factor and sonic modulus all decrease, especially for the Young's modulus of HMLS. After oiling treatment, the linear density of the three yarns increases, but the breaking strength, Young's modulus and thermal shrinkage decrease, and the elongation at break and crystallinity have little change. The sonic orientation factor and sonic modulus of GHT and HMLS are higher after oil treatment. Compared with the other two yarns, SLS after being oiled and dried at 75 ℃ has less mechanical strength and modulus loss, greater reduction in thermal shrinkage ratio, better dimensional stability, and higher crystallinity, which indicates that SLS is more suitable for activation modification among polyester industrial yarns.
In this paper, the effects of activating oil agents and different drying conditions on the performance of GHT, HMLS and SLS polyester industrial yarns provide a new idea for the selection of polyester industrial yarns and the activation of polyester industrial yarn treatment process, and also provide a reference for the subsequent application of enhanced composite materials for polyester industrial yarns. 


Effects of activating oil and activating conditions on the interfacial adhesion of polyester industrial yarn /rubber

SHI Qiang, REN Chunying, SHI Jiaoxue, ZHENG Xiong, ZHANG Xuzhen

2023, 31(3):  163-171. 

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In recent years, the demand for tires in China is increasing rapidly, in which radial tires are the main product. HMLS polyester industrial yarns have obvious advantages as the frame material of tire due to low cost, small elongation deformation, good dimensional stability, high modulus and low thermal shrinkage. However, the modulus and polarity of the HMLS polyester industrial yarn and rubber have great difference, leading to low interface adhesion, and a peeling failure. Therefore, it becomes an important research direction to enhance the bonding performance of the interface between the polyester industrial yarn and rubber.
    In this paper, based on the existing conventional methods of preparing polyester cords by dipping polyester industrial yarns, the one-step dipping method is improved to make its performance close to that of the product by two-step dipping. In the two-step dipping method, resorcinol formaldehyde latex (RFL) is used to pretreat polyester industrial yarns and then compounded with rubber to achieve a high interface adhesion. While in the one-dip method, the yarn can be oiled with an activated oil agent during spinning, and RFL and rubber matrix compounding can be carried out without pre-treatment of polyester industrial yarns. Compared with the two-dip method, the one-dip method has the advantages of short process, energy saving and consumption reduction, but the bonding strength between the polyester industrial yarn and rubber is lower. In this paper, the blocked isocyanate is added to the activated oil agent and then oil is applied during spinning. The polyester industrial yarn is dipped in the one-dip method, and then compounded with rubber. During the subsequent vulcanization of rubber, the blocked isocyanate component is simultaneously activated by thermal effect to realize the interface reinforcement between the fiber and rubber. The effect of emulsion mass fraction of activating oil, amount of blocked isocyanate and activation technology on the interfacial adhesion between the polyester industrial yarn and rubber were systematically studied. The results show that, the adhesion fastness of RFL on the surface of the polyester industrial yarn increases at first and then decreases with the increase of emulsion mass fraction of activating oil. The maximum H-pull force of the polyester industrial yarn/rubber reaches its maximum value at an emulsion mass fraction of activating oil of 5%. With the increase of the blocked isocyanate content, the adhesion fastness of RFL on the surface of the polyester industrial yarn, the H-pull force and peeling strength of polyester industrial yarn/rubber increase at first and then decrease, and the maximum values are recorded at a blocked isocyanate content of 2%. With the increase of activation temperature or activation time, the H-pull force of polyester industrial yarn/rubber firstly increases and then decreases, and reaches the peak value at 140 ℃ or 2 h. The H-pull force of polyester industrial yarn/rubber treated with activating oil (containing isocyanate) is 21.1N, almost twice of the force for the similar samples obtained via the general one-dip method, and significantly reducing the difference with that of the two-dip treated samples (H-pull force 27 N). Compared with the similar commercial products, the H-pull force of polyester industrial yarn/rubber and the dimensional stability of polyester cord treated with activating oil containing isocyanates are significantly improved.
Based on the one-dip method, the polyester industrial yarn is modified with activating oil (containing isocyanate) and contributes the adhesion between the polyester industrial yarn and rubber without affecting its dimensional stability. This study provides a new idea for the modification of polyester industrial yarns for cords, and also provides a reference for the modification of other tire frame materials.


Preparation of β-cyclodextrin porous materials and their adsorption of methylene blue in simulated dyeing wastewater

HAO Xing , CHEN Yihang , LI Ni , MA Mingbo , LIU Yinli , ,

2023, 31(3):  172-181. 

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As an important basic force of people's livelihood industry and a pillar industry of national economic development, China's textile industry has made remarkable development achievements. However, the environmental problems caused by the discharge of printing and dyeing wastewater cannot be ignored. According to incomplete statistics, the water consumption of one ton of textiles in China is 100～200 tons, and the large amount of wastewater discharge increases the difficulty of water treatment. In order to remove the pollutants with complex composition in printing and dyeing wastewater, the common printing and dyeing wastewater treatment methods including the physical method, the chemical method and the biological method are adopted. Among them, the adsorption method in the physical method is simple in operation, low in cost and energy consumption, and causes no secondary pollution. It can not only effectively decolorize, but can also adsorb heavy metal ions, remove substances that are not easily degraded chemically and biologically in water. In addition, most of the adsorption process is reversible, which can make the adsorption material be recycled through the desorption process. It is especially suitable for the treatment of printing and dyeing wastewater with increasingly complex components and has broad application prospects.
However, the pollutant removal performance of traditional adsorption materials is difficult to meet the requirements of printing and dyeing wastewater treatment, and the recycling performance is poor and the energy consumption is large. β-cyclodextrin is a cyclic oligosaccharide composed of glucose molecules linked by α-1,4 glycosidic bonds and is naturally non-toxic, cheap and easy to obtain, and biocompatible. It has a large number of hydroxyl groups on the outside, which can be modified by a variety of functional groups to obtain β -cyclodextrin derivatives. The internal special cavity structure can envelope a variety of organic/inorganic pollutant molecules. In the synthesis and application of β-cyclodextrin-based adsorption materials, it is often necessary to modify or graft β-CD to prepare water-insoluble β-CD-based adsorption materials and enhance their application effect. At present, there are mainly two types of β-CD crosslinked polymer adsorption materials and chemically immobilized β-CD-based adsorption materials.
In this paper, β-cyclodextrin (β-CD), methacrylic anhydride (MA) and sodium p-styrene sulfonate (SS) were used as raw materials to prepare the crosslinked polymer S-M-β-CD containing sulfonic acid group (SO3H) by dehydration condensation reaction and carbon-carbon double bond addition reaction. The microstructure characteristics of S-M-β-CD were studied. The adsorption mechanism of S-M-β-CD for methylene blue (MB) was analyzed. It is concluded that S-M-β-CD is a spherical block structure with rough, porous and uneven surface, and contains a large number of mesopores and trace micropores, which are helpful for the adsorption of pollutant MB. S-M-β-CD can still maintain 98.15 % adsorption rate for MB after seven cycles of desorption-adsorption, indicating that it has excellent adsorption-desorption properties. When the pH of MB solution is 9, the adsorption effect of S-M-β-CD on MB is the best, and the adsorption rate is close to 99.00 %. The adsorption process of MB by S-M-β-CD is more in line with the pseudo-second-order kinetic model and Langmuir isothermal adsorption model, that is, the adsorption process is monolayer adsorption dominated by chemical adsorption and synergistic effect of physical adsorption.
It has been more than 120 years since Villiers discovered cyclodextrin. β-CD has been widely sought after by researchers for its special spatial structure. Nowadays, the synthesis and development of adsorption materials based on β-cyclodextrin have attracted more and more researchers' attention. Based on the systematic study of S-M-β-CD adsorption materials, we hope to provide feasible research ideas and methods for the development and application of new adsorption materials with low cost and high efficiency.


Synthesis of tristyrylphenol polyoxyethylene ether phosphate and its dispersing property for dyes

LI Jianhao, XIONG Chunxian, ZHANG Yunju, YU Jianhua, SUN Yangyang, XU Yueping, LIU Chenghai

2023, 31(3):  182-187. 

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Liquid disperse dyes have become a research hotspot in recent years because they are able to meet the requirements of automation of printing and dyeing, batching systems, as well as energy saving in production. However, the liquid disperses dyes with a low dosage of dispersant are easy to be coarse and even coagulated and precipitated. In the process of immersion dyeing, the dispersion stability at high temperatures is poor, and the dye precipitates out, which leads to a problem of uneven dyeing and poor reproducibility. So, the dispersant is the key to preparing high-performance liquid to disperse dyes.
    The tristyrenylphenol polyoxyethylene ether (TSPOE-n) was esterified with phosphorus pentoxide, and hydrolyzed to obtain the tristyrenylphenol polyoxyethylene ether phosphate (TSPOEP-n; n=13, 16, 20 and 29), which was used as a dispersant for the liquidation of disperse dyes. The chemical structure of the dispersant was characterized by the infrared spectrum. The effect of ethylene oxide (EO) number in TSPOEP-n on the storage stability of liquid dispersed dyes was investigated by particle size analyzer, and the dyeing properties of liquid and powder disperse dyes were compared.
    The liquid disperse dyes prepared by dispersant TSPOEP-n (n=13, 16, 20 and 29) with EO numbers were all nanoscale and the average particle size was 175~215 nm. The PDI was about 0.2, and the absolute value of Zeta potential was greater than 25 mV. After 100 days of storage, when the EO number was 13, 16, 20, and 29, the dispersed dye particle size increased by 35.3, 20.2, 34.4, and 58.8 nm, respectively. Disperse dyes' particle size and distribution tended to be stable. And the average particle size was less than 350 nm, which could meet the dyeing requirements. After the dispersed dyes were heat treated at a high temperature (130 ℃) and filtered by double-layer filter paper, there were a small number of dye particles on the filter paper and the dye filtration time (stage)/residue rating (stage) reached C/3 or above. When the dye mass fraction was 1%~5%, the unevenness of the fabric dyed by liquid disperse dye was slightly higher than that of the sample dyed by powder dye. In addition, with the increase in the amount of the liquid dye, the unevenness decreased while the dye evenness improved significantly. On the other hand, When the dye mass fraction was greater than 2% and the dyeing unevenness value was less than 0.05, which indicated good dyeing evenness. Also, the COD of the residual liquid of liquid disperse dye was about 35.7% lower than that of powder dye.  
    The tristyrenylphenol polyoxyethylene ether phosphate (TSPOEP-n) obtained from the esterification and hydrolysis of phosphorus pentoxide was used as the dispersant for the grinding and fluidization of dispersed blue 79. The results show that when n values were 13, 16, 20, and 29, the dispersant prepared has high dispersion and the stability efficiency for dye particles is significant. The average particle size of the four liquid disperse dyes is less than 215 nm. During normal temperature storage, the particle size of liquid disperse dyes tends to be stable at about 100 days, and the dyes have good high-temperature dispersion stability. When TSPOEP-16 is used as a dispersant, the particle size increase of dyes stored at room temperature is only 20.2 nm, and the dye uptake is significantly higher than that of powder disperse dyes. The COD of the dye residue after dyeing is reduced by 35.7% compared with that of powder dyes.


reparation of organic pigment waterborne dispersion system and investigation to its dyeing properties on cotton fabrics

SONG Jialia, LI Yunjinga, HAO Longyuna, b, c

2023, 31(3):  188-193. 

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In this study, nonionic surfactant NP-10 and cellulase were used to prepare a stable organic pigment waterborne dispersion system, whose dyeability on cationically modified cotton fabrics was studied. The UV absorption spectrum revealed that NP-10 and cellulase were associated in solution by hydrophobic interaction. The stability test showed that cellulase could improve the stability of pigment dispersion. The particle size test showed that cellulase helped to reduce the particle size of pigment. The potential test indicated that the addition of cellulase could increase the zeta potential of pigment particles. The color depth test showed that the addition of cellulase could help to improve the dyeing depth, and the maximum dyeing depth could be obtained under the condition of pH 4.

Preparation of polyurethane foam coated fabric and its sound insulation properties

2023, 31(3):  194-202. 

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 In recent years, coating finishing has become one of the important methods of functional finishing of textile materials. Coating finishing is to evenly coat the surface of the fabric with a layer of polymer compounds that can form a film, so as to change the performance and style of the fabric and improve the added value of the textile. At present, among many coating materials, water-based coating materials stand out because of their environmental protection. Specifically, waterborne polyurethane (PU) coating is a high-quality coating material with high tensile strength, good elasticity and amphiphilicity. It can be used in foaming preparation process, and the foam coated fabric is widely used. For example, soft foam is used as the padding of vehicles, rooms and clothing, and hard foam is used as heat insulation, sound absorption, packaging, insulation and low foaming synthetic wood. Therefore, it is feasible to finish the fabric with foaming coating to make it obtain a relatively soft structure and improve its sound insulation performance.
In order to develop a multi-functional wall fabric with sound insulation and noise reduction, the warp knitted polyester fabric was waterproofed by padding process to obtain a certain hydrophobicity and the polyurethane (PU) foam coating was used for waterproofing functional finishing of base fabric. The effects of different preparation process parameters on the peeling fastness and sound insulation performance of the coated fabrics were explored, and the application advantages of PU foam coated fabrics as wall covering fabrics were analyzed. The results show that when the dosage of PU in the coating slurry formulation is 100 g, the mica powder is 30 g, and the thermally expandable microspheres are 2 g, the baking temperature is 170 °C, the baking time is 60 s, and the knife distance is 0.58 mm, the PU foamed coating fabric is prepared, the peeling fastness of PU foaming coating fabric is 17 N, the average sound insulation amount could reach 26 dB, and the coating peeling fastness and sound insulation performance reach the best.
In the future, wall cloth will gradually replace wallpaper, and consumers have more and more requirements for the performance of wall cloth, such as waterproof, insect control, environmental protection, sound absorption and other versatility. At the same time, consumers are more looking forward to the safety of decoration, anti-fouling and easy scrubbing, antibacterial and mildew resistance, and the diversification of colors and patterns of wall cloth. In conclusion, this kind of waterproof, soundproof and noise reduction multifunctional coated fabric has a broad application prospect in the wall covering market.


Preparation of boron nitride/polyurethane fabric coating and its cooling performance

ZHANG Jun, LI Yutao, CHEN Xiaolong, YANG Lei, , SHEN Yifeng, , JIANG Fang, ,

2023, 31(3):  203-211. 

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With the continuous improvement of people's living standards, people's demand for clothing has undergone a more diversified transformation. The diversity of consumption makes the market put forward more requirements for the functionality of fabrics. At present, some consumers are more concerned about the softness, wrinkle resistance, and windproof or waterproof performance of clothing, while others are more concerned about the breathable perspiration, cool, and anti-ultraviolet ability of clothing. With the aggravation of global warming, summer extreme temperatures and duration continue to increase, and more and more people realize the importance of fabric heat dissipation ability. Up to now, most of the methods used to improve the heat dissipation capacity of fabrics are to change the fabric structure, increase the heat dissipation porosity, and obtain functional fabrics by adding cool fibers prepared by thermally conductive materials or constructing thermally conductive coating by the grafting load to increase the surface thermal conductivity. However, the former tends to lose the mechanical properties of the fabric due to the increase of voids and has the defects of high energy consumption, high cost, long process, and low efficiency in the spinning process. Therefore, more and more attention would be paid to improving the thermal conductivity of fabrics by grafting loading.
In order to effectively improve the cooling performance of the fabric, the thermally conductive coating constructed by boron nitride (BN)/polyurethane (PU) was studied to improve the cooling effect of cotton fabrics. Starting from the two-dimensional layered thermally conductive material BN, firstly, functionalized BN (FBN) was prepared with ultrasonic stripping as the thermally conductive filler of the functional coating. Then, the cotton fabric was grafted with a silane coupling agent to obtain the modified cotton fabric with abundant hydrogen bonds and active groups on the surface, which is convenient for the effective adhesion of subsequent coatings. Finally, the aqueous PU (WPU) was used as the polymer substrate supported by the coating, and a certain amount of FBN and WPU was configured into the required functional coating dispersions in a certain proportion. The FBN/WPU functional coating was successfully loaded on the modified cotton fabric by the method of one dipping and one rolling and hot setting. In this paper, the thermal conductivity filler FBN was successfully attached to the fabric surface by the efficient combination of the active groups rich in silane coupling agents and WPU. Compared with the functional thermal conductivity fiber, the research method in this paper greatly reduced the production cost. It was found that when the ratio of silane coupling agent to water to ethanol was 1:1:3 and the FBN mass fraction was 15%, the final thermal conductivity of cool fabrics was increased by 811% compared with cotton fabrics. In addition, the coolness coefficient of the fabric was tested. The coolness coefficient of the fabric finished by functional coatings reached 0.220 J/(cm2·s), which met the national standard of China.
The diversified demand requires the market to make more changes to cope with the future environment. We believe that, with the increasing demand for cool fabrics, how to improve the cooling performance of fabrics and maintain the comfort of the body feeling will attract more and more people's attention. The research results can provide a reference for the design and development of functional fabrics.


Research progress of cellulose electrospinning and its derived nanofibers in biomedicine applications

YANG Haizhen, WEI Sujie, MA Chuang, ZHOU Zelin, WANG Mengjia, FU Yuan

2023, 31(3):  212-224. 

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 Cellulose is a macromolecular polysaccharide composed of glucose, which has good biocompatibility, degradability and compatibility with other substances; Cellulose derivatives are the products of cellulose esterification or etherification, which make up for the limitations of the physical and chemical properties of cellulose, and can better meet the different needs of the medical field after modification. Therefore, cellulose and its derived nanofibers have good application prospects in tissue engineering scaffolds, wound dressings, drug delivery/delivery, antibacterial and medical devices.
Cellulose is a rich renewable resource, which can inhibit the growth of saprophytic bacteria, cholic acid and anaerobic bacteria, reduce the cholesterol content in the blood, reduce the deposition of cholesterol on the blood vessel wall, and prevent arteriosclerosis. However, due to the strong hydrogen bond network between cellulose molecular chains and highly crystalline aggregation structure, it is difficult to process cellulose, and other materials are also difficult to adsorb on cellulose. With the development of electrospinning technology, the treatment steps of cellulose have been simplified, and its position in the medical field has also been improved.
Nanocellulose can be matched with human skeleton, which improves the mechanical properties of the derivative antibacterial film and makes it have good antibacterial activity against Staphylococcus aureus and Escherichia coli. In the simulated cell solution, it is highly similar to the extracellular matrix, and there is no rejection in the human body. Due to its low toxicity and excellent degradability, cellulose derivatives can control the drug delivery rate and deliver drugs to target cells in drug carriers. In recent years, nano cellulose has made great progress in the field of human motion monitoring. The research shows that three-dimensional nano cellulose in the form of aerogel can be used as a medical wearable human monitoring system to simulate the characteristics of human skin for comprehensive monitoring of the human body.
The research of cellulose electrospinning and its derived nanofibers is an effective way to strengthen the short board in the biomedical field. Studies confirm that electrospun cellulose nanofibers are smaller than cells in diameter and can simulate the structure and biological function of natural extracellular matrix. How to functionalize cellulose in the biomedical field has become a research hotspot.
At present, natural polymer materials are widely used in the field of biomedicine, and cellulose, as an important part of them, has great application potential. It is a research hotspot in the field of biomedicine to functionalize inanimate materials and transform them into living tissue materials to reduce the rejection of materials in the human body. Cellulose has unique advantages due to its good biocompatibility and high controllability. However, due to the hydrogen bond network structure of cellulose itself, it is difficult to dissolve cellulose. How to dissolve cellulose efficiently has been the focus of research. Therefore, it is necessary to conduct more in-depth research on the dissolution mechanism, develop a clean and efficient cellulose dissolution technology, and form cellulose derived materials through electrospinning reconstruction or blend with other materials to improve the application of cellulose nanofibers in the biomedical field.


Research progress on the relationship between composition structure and mechanical properties of waterborne polyurethane and its dyeing properties

HAN Yulan, SONG Bing, LI Chunlin, DU Yuanyuan, NIU Jiarong

2023, 31(3):  225-236. 

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Compared with traditional solvent based polyurethane, waterborne polyurethane (WPU) has greatly reduced the use of organic solvents, which can effectively reduce environmental pollution, and is attracting more and more attention. However, the introduction of hydrophilic groups in WPU will affect its mechanical properties and limit the scope of use of WPU products. In this paper, the relationship between the composition, structure and mechanical properties of WPU was described, and the research status of WPU dyeing was introduced and summarized, in order to provide reference for the development of waterborne polyurethane microfiber leather.

Research progress of carbon fiber high-temperature resistant sizing agent

WANG Nanaa, HUANG Liqiana, XU Jinyunb, ZHOU Cuna,

2023, 31(3):  237-250. 

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In the preparation process of carbon fiber, sizing is an indispensable process, its function is to form a uniform layer of organic polymer thin layer on the surface of carbon fiber, protect the surface activity of carbon fiber, enhance the wettability, reactivity, adhesion of carbon fiber surface, etc., which is conducive to improving the bonding performance between fiber and resin matrix, and enhancing the comprehensive performance of composite products. The sizing agent is generally composed of polymer resin as the main body, with various surfactants and additives. Mainly divided into three categories: solvent-based sizing agent, emulsion-type sizing agent and water-soluble sizing agent, water-soluble sizing agent has become the mainstream of carbon fiber and its composite material research and development because of its storage stability, good safety and low environmental pollution.
In recent years, China's carbon fiber industry has shown explosive development, and the development and application of polymer-based carbon fiber composites in frontier fields such as aerospace, high-speed rail, new energy vehicles and fuel cells have developed rapidly, which has put forward higher requirements for the development of high-performance carbon fiber composites. The decomposition temperature of conventional sizing agent is about 200 °C, which is easy to thermally decompose under the conditions of high-temperature processing and molding process of high-temperature resistant and high-performance resin, resulting in local defects in the interface layer of the material and affecting the overall performance of the composite material. In order not to affect the high temperature resistance of the composite material, it is necessary to develop a high temperature resistant sizing agent that matches the high temperature resistance of the resin matrix.
Based on the relevant literature in recent years, it can be seen that the high temperature resistance of the sizing agent is mainly achieved by the high temperature resistance of the main resin of the film former, physical and chemical modification such as blending and copolymerization, or the performance optimization of the hybrid and sizing agent formula of nanomaterials. In this paper, the research progress of high-temperature resistant carbon fiber sizing agents in recent years is reviewed, and the traditional thermosetting resins and rapidly developing high-temperature thermoplastic resins and their modified products are classified and summarized as various types of sizing agents with their modified products as the main components, focusing on their modification methods, especially water-based modification methods, and analyzing the application properties of various sizing agents, such as water solubility, high temperature resistance, surface properties and its influence on the mechanical properties of composite materials. From the perspective of industrial application, it is proposed that in addition to the research on hot spot properties and preparation methods, carbon fiber sizing should also pay attention to the research on the overall application of sizing agent, such as the stability, wettability, particle size distribution of sizing emulsion, the surface interface properties and overall mechanical properties of carbon fiber and composite materials after sizing. Finally, according to the development status of carbon fiber sizing agent and the performance requirements of advanced high temperature resistant resin-based carbon fiber composites, the development of high temperature resistant waterborne carbon fiber sizing agent is prospected.


Review of commonly used antibacterial finishing agents for textiles

LU Jiayu, CAI Guoqiang, GAO Zongchun, SONG Jiangxiao, ZHANG Yan, QI dongming,

2023, 31(3):  251-262. 

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Textiles are widely used in many fields, such as clothing, domestic decoration and industrial use. They not only provide a place for the grouth and reproduction of various microorganisms, but also become an important transmission route of some infectious diseases due to their reusable characteristics. In recent years, considering the complex and severe global environmental epidemic and the frequent occurrence of various infectious diseases, the use of antibacterial agents on textiles is an important way to improve their antibacterial and bacteriological properties and cut off or slow down the spread of pathogens. Therefore, the functional characteristics and development trend of various antibacterial agents commonly used in textiles have attracted much attention.
This paper firstly introduces the inorganic, organic and natural antibacterial agents which are widely used in textiles. And the types, characteristics, mechanism of action and antibacterial effect of these compounds are described respectively. Inorganic antibacterial agents are the most widely used antibacterial agents. Nano silver and nano gold as typical antibacterial agents of metal nanoparticles, have high surface energy. They generally destroy the cell structure of bacteria or affect their metabolism by acting with the cell membrane of bacteria. Although they have good antibacterial effects, they are easy to agglomerate and leach from the textile. The antibacterial effect of metal oxides, such as titanium dioxide, zinc oxide and magnesium oxide, is next only to that of metal nanoparticles. There are three main antibacterial mechanisms, such as active oxygen generation through photocatalysis, metal ion action and cell mechanical damage. Carbon nanomaterials have also been studied in the field of antibacterial. It is believed that graphene, carbon nanotubes and graphene oxide can cause physical damage to bacterial cell membrane or cell distortion through contact and interaction with bacteria by their physical structure and excellent mechanical strength, and thus producing antibacterial effects. Organic antibacterial agent is the earliest applied antibacterial agent . They are much easier to prepare and possess a broad spectrum of antibacterial properties, mainly including quaternary ammonium salts, halide amines, triclosan and so on. They kill the bacteria mainly through the chemical bond force, such as electrostatic attraction, van der Waals force, hydrogen bond and so on. Halide amines are considered to be the most effective organic antibacterial agents, which can be cyclically sterilized by artificial chlorination. Although organic antimicrobials have broad-spectrum antibacterial properties, they may be toxic to the environment and human cells. Natural antibacterial agents such as curcumin, chitosan, plant polysaccharides,possess biocompatibility and biodegradability. And they have been paid more and more attention in the antibacterial finishing of textiles, one of the most familiar is chitosan. The amino group on chitosan makes it carry a positive charge, which can be combined with the electrostatic interaction between the bacterial cell membrane and change the permeability of the cell membrane, resulting in cytoplasmic outflow and cell death. But at present, the overall efficiency of natural antibacterial agents is not effectively enough, and the range of use is relatively not extensive. In this paper, two methods of antibacterial finishing of textiles are summarized. One is to prepare antibacterial fiber by directly adding antibacterial agent to spinning liquid seed in the spinning process. The second is the functional finishing method using antibacterial agent on the fabric surface; At last, the paper summarizes three methods of testing textile properties, such as bacteriostatic zone method, absorption method and oscillation method.
At present, problems such as low antibacterial efficiency, poor antibacterial spectrum and insufficient durability need to be solved by antimicrobial agents in textile finishing. At the same time, the problem of poor sensitivity after finishing by antibacterial agents can not be ignored. With the upgrading of  use demand and the enhancement of safety and environmental protection awareness, the construction of durable and effective antibacterial coating on textile surface, and study of antibacterial agent type, structure and textile compound antibacterial effect, interface performance and wear evaluation, have become important development directions of antibacterial textile research in the future.


 Review on fabric dry electrode for long time continuous and stable EMG monitoring on human skin

SHI Junminga, b, MENG Fenye , HU Jiyonga, b

2023, 31(3):  263-273. 

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Electromyography (EMG) is an important pathological information of muscle-nerve diseases, and its long-term continuous and stable monitoring is critical for application in diagnosis. We firstly reviewed the electrode types and working principle of EMG monitoring, and then specifically outlined the current fabric dry electrode technology for long time continuous stable electromyographic monitoring in terms of fabric structure and manufacturing techniques, performance characterization and evaluation technique, and the integration technology into clothing. After summarizing the existing technical limitations and the futuristic trend, we point out that improving the strain stability and perspiration corrosion resistance of fabric dry electrodes is the current technology that needs to be broken through.

Research progress of functional magnetic resonance imaging in brain perception induced by fabric stimulation

ZHAI Shunaa, LOU Lina, b, c, WANG Qicaid, YUAN Jiea, b

2023, 31(3):  274-284. 

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At present, the brain perception mechanism in the field of fabric comfort is not clear, and the existing characterization technology of fabric comfort has not been quantified. Functional magnetic resonance imaging technology has shown good technical advantages in the field of fabric stimulation brain perception representation with its high spatial resolution, which is of great significance for exploring the brain perception mechanism of fabric comfort. 
By exploring the changes between stimulation signals and brain activation signals, fMRI technology can effectively and accurately identify the relevant brain regions under fabric stimulation, and complete the brain in situ perception representation of fabric comfort. This paper reviews the research status of brain perception of fabric stimulation based on fMRI technology from three fields of tactile stimulation, visual stimulation, and visual-tactile cross-stimulation. Among them, the somatosensory cortex, motor cortex and ventral visual cortex are the relevant response brain regions for tactile stimulation, visual stimulation and visual-tactile cross-stimulation. The characteristic indicators are mainly activation intensity and activation proportion.
At present, the study of brain perception of fabric stimulation based on fMRI technology has become a popular research topic. It has been confirmed that the activation point coordinates, activation intensity, activation proportion, functional connectivity and other information of relevant brain regions under fabric stimulation can effectively represent the brain perception of fabric stimulation, which provides great potential for in situ representation of fabric stimulation.
Based on the principle of brain perception representation of fMRI technology, this paper summarizes the research status of brain perception of fMRI technology in fabric slight touch stimulation, contact pressure stimulation, visual stimulation, visual-tactile cross-stimulation. It is concluded that SI, SII and motor cortex in the somatosensory cortex are related to slight touch stimulation and contact pressure stimulation of fabrics. Among them, SI is related to smoothness and softness, and SI, SII and motor cortex are related to roughness, adhesion and itching. On the right side, SII is the fabric comfortable pressure perception brain area, SI and amygdala are the fabric uncomfortable pressure perception brain area, while amygdala is the fabric compression pressure perception brain area. The changes of functional connectivity between SI and SII are related to the duration of stress stimulation. The ventral visual cortex brain network is not only a relevant brain area for the perception of fabric visual stimuli, but also a multi-sensory representation brain area for material properties. The fusiform gyrus is not only sensitive to material category perception, but also related to visual short-term memory. In the future fabric stimulation process based on fMRI technology, it is important to master and control or eliminate interference factors for fabric comfort representation research. However, in the field of thermal and wet stimulation of fabrics, the brain mechanism of short-term memory of fabric properties, the flow process and effective connection of characteristic activated brain regions, and the dynamic adaptation and regulation mechanism of brain regions under long-term stimulation need to be further explored.