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Article
Publication date: 23 July 2018

Wenbin Li, Weilin Xu and Xin Wang

Clothing is subject to a dynamic thermal transport process in its routine service in which the apparel and human body together with environment interact with each other…

Abstract

Purpose

Clothing is subject to a dynamic thermal transport process in its routine service in which the apparel and human body together with environment interact with each other. Understanding of the thermal transfer in this case should take the variations of human body and environment together with clothing attributes into consideration. The paper aims to discuss these issues.

Design/methodology/approach

Based on the purpose-built dynamic thermal and moisture tester, this study focuses on the thermal transfer of fabrics in different rotational motions. The energy consumption and power of the simulated human skin, the temperature and the thermal retention rate were monitored in the process of rotation of the testing platform with gradually increased rotating speed.

Findings

It has been found that the thermal transfer of a rotating fabric is greatly affected by the rotating speed, the angle of the fabric toward the moving direction and the attributes of the fabric such as its thickness, layers, structure and its fiber composition.

Practical implications

This study will benefit the understanding of the dynamic thermal interaction of human with the environment, and the designing of clothing with excellent thermal comfort.

Originality/value

This work reveals the dynamic thermal transfer of fabrics in rotational motions. It provides a platform to study the dynamic thermal behavior of clothing in daily use.

Details

International Journal of Clothing Science and Technology, vol. 30 no. 4
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 1 November 2008

Xin Wang, Weilin Xu, Weigang Cui, Wenbin Li and Xungai Wang

Fibers based regenerated protein draw much attention for recycling discarded protein resources and can produce biodegradable and environmental friendly polymers. In this…

Abstract

Fibers based regenerated protein draw much attention for recycling discarded protein resources and can produce biodegradable and environmental friendly polymers. In this study, superfine wool powder is blended with polypropylene (PP) to produce wool powder/PP blend film through extrusion and hot-pressing. Hydrogen peroxide is used to bleach the black colored surface of the blend films. The effects of peroxide concentration, bleaching time and powder content on the final whiteness and mechanical properties of the blend films are investigated.

The bleached films are dyed with acid red dyes and the dyed color is evaluated using a Computer Color Matching System. Color characters of dyed films, such as L*, a*, b*, ΔE*ab, C*ab and K/S values are measured and analyzed. The study not only reuses discarded wool resources into organic powder, widens the application of superfine wool powder on polymers, but also improves the dyeing properties of PP through the addition of protein content.

Details

Research Journal of Textile and Apparel, vol. 12 no. 4
Type: Research Article
ISSN: 1560-6074

Keywords

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Article
Publication date: 1 May 2008

Weigang Cui, Xin Liu, Xiaolin Shen, Xuqiang Peng and Weilin Xu

In this paper, silk powder around 1.5 micrometer average in size was developed and its dyeing property was compared with normal silk fiber. The results show that silk…

Abstract

In this paper, silk powder around 1.5 micrometer average in size was developed and its dyeing property was compared with normal silk fiber. The results show that silk powder has a very high dye uptake property and can be dyed at room temperature; it can also be used to improve the dyeing property of some materials when it acts as a kind of additive agent. The K/S value of silk fiber is higher than that of silk powder. Their K/S value of silk fiber and silk superfine powder are influenced largely by the dye concentration. The WXRD diffraction curves showed that the crystallinity of silk powder is lower than that of silk fiber. FTIR spectra of silk powder showed that the intensity peak of CH2-antisymmetrical stretching vibration largely decreased, and the peak of C=O symmetrical stretching vibration of amid bond moved to the high wave-number. TG patterns of samples showed that water (moisture) could be easily removed from the powder when the temperature was over 70°C, and the initial decomposition temperature of silk powder increased from 262.5°C to 277.5°C. Moreover, the silk powder showed higher residue than that of silk fiber at 600°C.

Details

Research Journal of Textile and Apparel, vol. 12 no. 2
Type: Research Article
ISSN: 1560-6074

Keywords

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Article
Publication date: 2 October 2009

Weigang Cui, Xin Wang, Wenbin Li and Weilin Xu

The purpose of this paper is to present a dynamic analysis on the thermal and electrical properties of fabrics under wet conditions.

Abstract

Purpose

The purpose of this paper is to present a dynamic analysis on the thermal and electrical properties of fabrics under wet conditions.

Design/methodology/approach

A purpose‐built apparatus is applied to test the thermal and electrical properties of textiles in moisture absorption and liberation process. Relation between temperature and resistance of a cotton/polyester double‐layer fabric is also analysed.

Findings

The surface temperature of textiles shows three different stages in the process. The electrical resistance is linearly related to the reciprocal of the moisture regain of fabrics. In the moisture absorption and liberation process, surface temperature of cotton layer is higher than that of polyester layer. And the electrical resistance of cotton layer decreases more quickly than that of polyester layer. The electrical resistance changes earlier than surface temperature in the moisture‐liberation process.

Practical implications

The paper is helpful in not only the designing of sportswear, but also the devising of moisture‐testing apparatus.

Originality/value

A dynamic testing method is applied to characterize the thermal and electrical properties of textiles.

Details

International Journal of Clothing Science and Technology, vol. 21 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 11 November 2013

Wenbin Li, Peiqing Jiang, Xin Wang, GaoWen Li and Weilin Xu

In this study, a novel dynamic testing method was established to measure the moisture variation of fabric surface during the process of moisture liberation in simulated…

Abstract

Purpose

In this study, a novel dynamic testing method was established to measure the moisture variation of fabric surface during the process of moisture liberation in simulated windy condition. The paper aims to discuss these issues

Design/methodology/approach

In this method, the samples were rotating during the test process so as to simulate the external windy environment. Effects of simulated wind speed, moisture regains and fabric materials on the surface moisture of fabric were investigated.

Findings

Experimental results showed that the surface moisture presented a trapezoidal moisture liberation curve, it increased at first, then kept stable for a while, and decreased finally with the increase of time. It took longer time for the fabric to complete the liberation process when the moisture regain of the fabric increased or the simulated wind speed decreased. The fiber materials of the fabric affected the time for the moisture liberation process under a specific windy condition.

Practical implications

This study will benefit the designing and development of clothing such as sportswear.

Originality/value

A dynamic testing method was proposed to characterize the surface humidity of textiles under simulated windy conditions.

Details

International Journal of Clothing Science and Technology, vol. 25 no. 6
Type: Research Article
ISSN: 0955-6222

Keywords

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Article
Publication date: 19 September 2018

Weilin Yang, Wentao Zhang, Dezhi Xu and Wenxu Yan

Robotic arm control is challenging due to the intrinsic nonlinearity. Proportional-integral-derivative (PID) controllers prevail in many robotic arm applications. However…

Abstract

Purpose

Robotic arm control is challenging due to the intrinsic nonlinearity. Proportional-integral-derivative (PID) controllers prevail in many robotic arm applications. However, it is usually nontrivial to tune the parameters in a PID controller. This paper aims to propose a model-based control strategy of robotic arms.

Design/methodology/approach

A Takagi–Sugeno (T-S) fuzzy model, which is capable of approximating nonlinear systems, is used to describe the dynamics of a robotic arm. Model predictive control (MPC) based on the T-S fuzzy model is considered, which optimizes system performance with respect to a user-defined cost function.

Findings

The control gains are optimized online according to the real-time system state. Furthermore, the proposed method takes into account the input constraints. Simulations demonstrate the effectiveness of the fuzzy MPC approach. It is shown that asymptotic stability is achieved for the closed-loop control system.

Originality/value

The T-S fuzzy model is discussed in the modeling of robotic arm dynamics. Fuzzy MPC is used for robotic arm control, which can optimize the transient performance with respect to a user-defined criteria.

Details

Assembly Automation, vol. 38 no. 5
Type: Research Article
ISSN: 0144-5154

Keywords

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Article
Publication date: 6 September 2018

Fakhrodin Lalegani, Mohammad Reza Saffarian, Ahmadreza Moradi and Ebrahim Tavousi

According to very small dimensions of the microchannels, producing a microchannel with smooth surfaces is approximately impossible. The surface roughness can have a…

Abstract

Purpose

According to very small dimensions of the microchannels, producing a microchannel with smooth surfaces is approximately impossible. The surface roughness can have a specific effect on microchannel performances. This paper aims to investigate the changes in friction and pressure drop in the microchannels by considering the different roughness elements on microchannel wall and changes in elementary geometry and flow conditions. Results show a significant effect of roughness on the pressure drop and friction.

Design/methodology/approach

Two-dimensional fluid flow in the rough microchannels is analyzed using FLUENT. Microchannels have a height of 50 µm. Water at room temperature (25°C) has been used as working fluid. The Reynolds numbers are considered in laminar flow range and from 50 to 300.

Findings

The results show that the value of friction factor reduces nonlinearly with an increase in Reynolds number. But, the pressure drops and the Poiseuille number in the microchannels increase with an increase in Reynolds number. The values of the pressure drop and the friction factor increase by increasing the height and size of the roughness elements, but these values reduce with an increase in the distance of roughness elements.

Originality/value

The roughness elements types in this research are rectangular, trapezoidal, elliptical, triangular and complex (composed of multiple types of roughness elements). The effects of the Reynolds number, roughness height, roughness distance and roughness size on the pressure drop and friction in the rough microchannels are investigated and discussed. Furthermore, differences between the effects of five types of roughness elements are identified.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 28 no. 7
Type: Research Article
ISSN: 0961-5539

Keywords

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