A Wearable Pressure Sensor Based on Ionogel/Textile for Human Motion Monitoring

Yu Dong,Qiujin Li,Zhiqi Zhao,Jixian Gong,Zheng Li,Jianfei Zhang 한국섬유공학회 2022 Fibers and polymers Vol.23 No.8

The growth of flexible sensors has always been challenging since the sensing behavior, mechanic performance andfatigue resistance remain to be improved. In this paper, a wearable pressure sensor with fast response and high sensitivitybased on ionogel/textile is fabricated. The ionogel is a double-network (DN) structure composed of polydimethylacrylamide(PDMAAm) skeleton and silica particles, carrying ionic liquids (ILs), which serves as a piezoresistive device. Byimpregnating and polymerization with the ionogel-prepolymer solution, a conventional cotton knitted fabric is converted intoa conductive and piezoresistive composite. The fabric serves as a ductile supporting matrix for the ionogel, supplementing thepiezoresistive contribution of the brittle silica network. This ionogel/textile composite has a high sensitivity (S=86.90 kPa-1)and durability, continuously outputting stable electric signal during monitoring the motion states of different joints in humanbody. Through the impregnation-polymerization approach, the selected areas toward to the specific joints positions inclothing can be fabricated into piezoresistive devices. The incorporation of textile improves the stress loading and sensingbehavior of the ionogel to work steadily under the sole of the foot for gait monitoring. This ionogel/textile device provides apotential formula of wearable sensors, stepping toward the burgeoning diversified-technologies assisted intelligence system.

Accuracy of the Different Calculation Methods of Specific Edge Load

LIU Huan,DONG Jixian,LUO Chong,DUAN Chuanwu,GUO Xiya,QI Kai,QIAO Lijie,ZHAO Zhiming 한국펄프·종이공학회 2020 펄프.종이기술 Vol.52 No.5

Heat Transfer Characteristics in Horizontal Rectangular Channel of Multi-Channel Cylinder Dryer

Lijie Qiao,Jixian Dong,Zhuozhi Yang,Sha Wang,Huan Liu,Bo Wang,Lingbo Kong 한국펄프·종이공학회 2020 펄프.종이기술 Vol.52 No.3

Effect of Combined Refining Plates with Different Bar Angles on Paper Properties during Mixed Pulp Refining

( Xiya Guo ),( Jixian Dong ),( Huan Liu ),( Chuanwu Duan ),( Ruifan Yang ),( Kai Qi ) 한국목재공학회 2020 목재공학 Vol.48 No.5

Pulp refining is the major way to alter the properties of fibers and formed paper. Different combinations of the bar profile of the rotor and stator during low consistency refining processes directly affect the properties of the paper. In this study, a mixture of softwood and hardwood pulp was refined by varying the bar angle of the stator while that of the rotor is fixed at 0°. The pulp samples were collected at different refining times. Then, the pulp and paper properties, such as beating degree, fiber external fibrillation, and tensile and tear indexes were measured to explore the effects of the combined refining plates at different bar angles on paper properties. The results of the experiment show that the combined refining plate of 0° and 5° recorded the most significant improvement in the pulp beating degree and fiber external fibrillation. This consequently increased the fiber bonding area, which in turn, improved both the tensile and the tear indexes of the paper. Also, the influence of the combined refining plates with a larger bar angle on the paper properties was weaker compared to that of smaller angles. This study not only provides ideas for the bar profile design but also improves the optimal selection of refining plates.

Parametric Design and Performance Characteristic of Isometric Curved Bar Plate Based on SEL and SSL

Huan Liu,Jixian Dong,Chuanwu Duan,Ruifan Yang,Xiya Guo,Bo Wang,Kai Qi,Lijie Qiao,Sha Wang 한국펄프·종이공학회 2019 펄프.종이기술 Vol.51 No.5

Curved bar plate is common used in the pulp refining, but its design method is rather vague due it complex shape. A design method of isometric curved bar plate using two main parameters, the starting point and bar angle of central curve, was proposed in this paper and the calculation of characterization parameters of specific edge load (SEL) and specific surface load (SSL) was described. Isometric curved bar plates designed by two methods, one with fixed starting point and various bar angles and another with fixed bar angle and various starting points, were analyzed by characterization parameters of SEL and SSL. It would be expected to design isometric curved bar plate by the first method and the SEL would be a useful refining intensity to measure it in actual refining, however, the refining characteristics of different isometric curved bar plates should be further studied. The study on the design of isometric curved bar plate would be conductive to the research of curved bar plate and rapid design of it.

Thermodynamic Analysis on Heat Recovery System of Hermetic Gas Hood for Paper Machine

Yan Yan,Dong Jixian 한국펄프·종이공학회 2020 펄프.종이기술 Vol.52 No.2

The working condition of hot air exchange system dramatically affects the operational status of the paper machine dryer, energy saving efficiency and paper quality of dryer section. After analyzing the heat recovery method and energy-saving effect of the closed air hood, it is found that the current process is limited by the design of the heat exchanger and the control system, and usually the preheated fresh air in the first-stage heat recovery device only recovers the sensible heat in the exhaust air of the air hood. Therefore, the common heat recovery process has been adjusted in this paper. The fresh air is firstly heated by latent heat with relatively low temperature in the exhaust gas, and then the sensible heat with relatively high temperature in the exhaust gas is recovered. The energy saving effect is calculated through an example. The calculation results show that this process can save about 20% energy compared with the original process.

Study on Fiber Cutting Performance of Isometric Straight Bar Plate with Different Bar Angle

Huan Liu,Jixian Dong,Xiya Guo,Chong Luo,Xiaohui Tian,Xiaojun Jiang,Sha Wang,Ruifan Yang,Chuanwu Duan,Bo Wang,Kai Qi 한국펄프·종이공학회 2019 펄프.종이기술 Vol.51 No.5

The refining plate is a direct-acting component of refiners in pulping, and the bar profile of it have a major impact on fiber cutting, which affects the paper forming and strength of the formed paper. In this paper, the fiber average length, the fiber length distribution, the original fiber cutting rate and adjacent fiber cutting rate of samples collected in different refining time are used to analyze the fiber cutting mechanism of the isometric straight bar refining plates with different bar angles. The results show that the fiber cutting performance of plates gradually decreases and the limit fiber cutting length of the plate increases with the increase of the bar angle which is opposite to the conclusion predicted by specific edge load (SEL). However, the fiber cutting action of plates is gradually weakened until the average fiber length is reduced to the limit cutting length of plates. Meanwhile, the cutting mechanism of the straight bar plates with different bar angles is different. The larger bar angle of plate, the lower fiber cutting rate and the adjacent cutting rate of which is basically kept constant during refining, while the adjacent cutting rate of smaller bar angle plate on fibers gradually decreases with refining and finally remains constant. The study on the cutting performance of different bar angle plates has positive significance for the selection and design of refining plates for different pulping process.

Refining Characteristics of Hardwood Pulp Using Straight- and Curved-bar Plates: A Time Series Study

Huan Liu,Jixian Dong,Xiaojun Jiang,Chong Luo,Xiaohui Tian,Ruifang Yang,Litao Zhang,Bo Wang,Yan Yan 한국펄프·종이공학회 2019 펄프.종이기술 Vol.51 No.5

There are obvious differences in the refining characteristics of plates with straight bars compared to curved bar plates having the same bar parameters during refining. The objective of this research is to explore the difference in the refining characteristics of the straight bar and curved bar plates on experimental and theoretical studies. The bar angle of the curved bar plate is defined, and the two plates are used in the refining of bleached sulphate eucalyptus pulp (BSEP). Samples at different refining times were collected, and the properties of the fibers, pulp, and paper were detected and analyzed. It was found that the curved bar and straight bar plates have a similar influence on the pulp SR freeness. However, the curved bar plate effectively retained the fiber length, which means that its fiber cutting effect is weaker than that of the straight bar plate. Meanwhile, the fiber external fibrillation of the samples refined by the curved bar plate was better than that of the samples refined by the straight bar, which showed a higher tensile and tear index of the formed paper. Through the theoretical analysis of refining intensity via characterization of the parameter bar edge length (BEL), the specific edge load (SEL) of the curved bar plate was lower, and the refining characteristics predicted by the refining intensity were similar to the results from the experiments conducted in this paper.

Design a Laboratory Rotating Test Bench for the Multi-Channel Dryer Experiment

Sha Wang,Jixian Dong,Changke Tan,Bo Wang,Lijie Qiao,Huan Liu 한국펄프·종이공학회 2019 펄프.종이기술 Vol.51 No.5

The dryer of paper machine has problem in discharging condensate water. When the dryer rotates at a high speed, the condensate water that is not discharged in time will form a water ring, resulting in low drying efficiency and high energy consumption. Thus, based on the multi-channel dryer proposed by others, a series of experiments was carried out on multi-channel dryer under static condition. However, due to the fact that the research condition of condensation and heat transfer of multi-channel dryer is not exactly the same as the actual working condition, the multi-channel dryer has not been introduced to the market. To address the above problems, this paper presented a rotating test bench which can better simulate the actual working condition of dryer and expounded the working principle of the test bench, as well as the design and calculation of rotary device of the test bench. Finite element analysis software was used to analyze the stress on the dryer channel. In order to avoid resonance problems, modal numerical analysis was conducted on the test bench, which provided experimental conditions for the further study of multi-channel dryer.

Effect of Pulp Properties on the Power Consumption in Low Consistency Refining

( Huan Liu ),( Jixian Dong ),( Kai Qi ),( Xiya Guo ),( Ying Yan ),( Lijie Qiao ),( Chuanwu Duan ),( Zhiming Zhao ) 한국목재공학회 2020 목재공학 Vol.48 No.6

The power consumption in the low consistency (LC) refining is an important indicator for the optimal control of the process and it is composed of the net power and the no-load power. The refining efficiency and process characterization of LC refining are directly affected by power consumption. In this paper, the effect of pulp consistency and average fiber length on the power consumption and refining efficiency were studied through the LC refining trials conducted by an experimental disc refiner. It is found that the curve of power-gap clearance can be divided into constant power section, power reduction section, and power increase section. And the no-load power and the adjustable domain of loading applied by the refining plates will increase as the increase of pulp consistency, while the increase of net power is larger than that of no-load power which makes the increasing of refining efficiency. Meanwhile, the adjustable domain of loading applied by the refining plates can be slightly improved by increasing the average fiber length, but its effect on the no-load power in the LC refining process can be neglected. The study of power consumption in LC refining is of positive significance for the proper selection of pulp properties in LC refining, in-depth exploration of refining mechanism, and energy consumption reduction in refining.