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Liu J.,Jiangnan University | Liu J.,Donghua University | Liu J.,National Engineering Research Center for Nonwovens | Bao W.,Wuxi Entry Exit Inspection and Quarantine Bureau | And 3 more authors.
Applied Acoustics | Year: 2014

In this paper, we propose a more general forecasting method to predict the sound absorption coefficients at six central frequencies and the average sound absorption coefficient of a sandwich structure nonwoven absorber. The kernel assumption of the proposed method is that the acoustics property of sandwich structure nonwoven absorber is determined by some easily measured structural parameters, such as thickness, area density, porosity, and pore size of each layer, if the type of the fiber used in nonwoven is given. By holding this assumption in mind, we will use general regression neural network (GRNN) as a prediction model to bridge the gap between the measured structural parameters of each absorber and its sound absorption coefficient. In experiment section, one hundred sandwich structure nonwoven absorbers are particularly designed with ten different types of meltblown polypropylene nonwoven materials and four types of hydroentangled E-glass fiber nonwoven materials firstly. Secondly, four structural parameters, i.e., thickness, area density, porosity, and pore size of each layer are instrumentally measured, which will be used as the inputs of GRNN. Thirdly, the sound absorption coefficients of each absorber are measured with SW477 impedance tube. The sound absorption coefficient at 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz and their average value are used as the outputs of GRNN. Finally, the prediction framework will be carried out after the desired training set selection and spread parameter optimization of GRNN. The prediction results of 20 test samples show the prediction method proposed in this paper is reliable and efficient. © 2013 Elsevier Ltd. All rights reserved. Source

Liu Q.,Jiangnan University | Xu Y.,Jiangnan University | Zhang H.,Jiangnan University | Li Y.,Wuxi Entry Exit Inspection and Quarantine Bureau | Deng B.,Jiangnan University
Polymer (Korea) | Year: 2014

The polypropylene/polyamide elastomer (PP/PAE) blends were prepared by melt mixing. PP and PAE in PP/PAE were immiscible completely. The size of PAE domains was large and the clear gap in the interface between PP and PAE existed, which did not meet the conditions enhancing toughness of polymers by elastomer. Therefore, maleic anhydride grafted polypropylene (MP) was used to improve the miscibility between PP and PAE. The miscibility between PP and PAE was improved and the size of dispersed phase PAE decreased by introducing MP. The crystallization of PP became easier by introducing PAE as a nucleating agent. With the increase of PAE content, the melt-crystallization temperatures of PP components in PP/PAE/MP blends increased gradually. The melt-crystallization of the polytetramethylene oxide segment of PAE component in PP/PAE blends were hampered by PP component. In addition, PAE can enhance significantly the toughness of PP, and the tensile strength and modulus did not decrease. Source

Xiang Q.,Donghua University | Lv Z.-J.,Donghua University | Yang J.-G.,Donghua University | Yin X.-G.,Wuxi Entry Exit Inspection and Quarantine Bureau
Applied Mechanics and Materials | Year: 2011

Due to absence of an integral mathematical model, quality control in spinning process has been hard problem for a long time. Rough sets theory (RST) is a methodology that effectively deals with the problems with inexact, uncertain or vague knowledge in a complex information system. Considering a mass of data from spinning process and inspection, as well as the variety of knowledge and experience from domain experts, an RST-based intelligent control model for spinning process is presented in this paper. In order to analyze the yarn strength when the characteristics of fibers are given, a rule extraction method based on RST is researched. The logical rules extracted from the decision table indicate that the initial strength of fibers is a key factor influencing on the yarn strength. At the same time, the different values combination of the final reduced attributes also obviously influence on the yarn strength in different degree when the certain nominal yarn is being processed. Therefore, RST method can be taken into account for spinners to choose suitable fiber materials in order to ensure the quality and reduce cost. © (2011) Trans Tech Publications. Source

Liu Q.,Shaoxing University | Zhang H.,Jiangnan University | Zhu M.,Wuxi Entry Exit Inspection and Quarantine Bureau | Dong Z.,Donghua University | And 10 more authors.
Fibers and Polymers | Year: 2013

The PLA/PAE blends with four different weight ratios were prepared by melt mixing. PLA and PAE in PLA/PAE blends were almost immiscible while the weak interaction between PLA and PAE existed. The sub-micrometer PAE domains were dispersed in PLA matrix uniformly. The physical aging of PLA could be inhibited by introducing PAE. For PLA/PAE, the structure formed by physical aging at room temperature induced the accelerated crystallization of PLA during heating. However, for neat PLA, the structure formed by physical aging had a negligible effect on the crystallization of PLA during heating. The isothermal crystallization kinetics of neat PLA and PLA/PAE were analyzed by Avrami theory. The values of Avrami exponent were within the range 2.1-3.0. The crystallization rate of PLA was enhanced significantly by addition of PAE. © 2013 The Korean Fiber Society and Springer Science+Business Media Dordrecht. Source

Liu Q.,Jiangnan University | Zhang H.,Wuxi Entry Exit Inspection and Quarantine Bureau | Deng B.,Jiangnan University | Zhao X.,Changzhou University
International Journal of Polymer Science | Year: 2014

Poly(3-hydroxybutyrate) [P(3HB)] and poly(3-hydroxybutyrate-co-3- hydroxyvalerate) [P(3HB-co-3HV)] are produced by various microorganisms as an intracellular carbon and energy reserve from agricultural feedstocks such as sugars and plant oils under unbalanced growth conditions. P(3HB) and P(3HB-co-3HV) have attracted the attention of academia and industry because of its biodegradability, biocompatibility, thermoplasticity, and plastic-like properties. This review first introduced the isodimorphism, spherulites, and molecular interaction of P(3HB) and P(3HB-co-3HV). In addition, the effects of 3HV content on the melting temperature and crystallization rate were discussed. Then the drawbacks of P(3HB) and P(3HB-co-3HV) including brittleness, narrow melt processing window, low crystallization rate, slow biodegradation rate in body, and so on were summarized. At last, the preparation, structure, and properties of P(3HB) and P(3HB-co-3HV) fiber were introduced. © 2014 Qingsheng Liu et al. Source

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