Search results

1 – 10 of over 7000
Article
Publication date: 23 August 2018

Zimin Jin, Lei Lei, Haitao Meng, Li Gao and Yuxiu Yan

The purpose of this paper is to measure the thermal and moisture resistance of the knitted upper fabrics with the foot model, which provided basis for designing and producing…

Abstract

Purpose

The purpose of this paper is to measure the thermal and moisture resistance of the knitted upper fabrics with the foot model, which provided basis for designing and producing sports shoes with thermal-moisture comfort.

Design/methodology/approach

In this paper, different yarn materials and fabric stitches were selected as the changing factors. The three kinds of yarn materials and the three kinds of fabric stitches were combined to design and weave eight pieces of knitted upper fabrics. Human sweating was simulated by the thermal-moisture comfort foot model, and then tested the thermal and moisture resistance of eight pieces of fabrics in different parts of the foot. Finally, the relationship between yarn material, fabric stitch, and the thermal and moisture resistance in different parts of the foot was analyzed by data.

Findings

The composition of the yarn material and fabric stitch has certain effect on the thermal-moisture comfort in different sections of the foot. When the yarn material of the four parts of the lateral arch, medial arch, ankle and heel is composed of 31.1tex moisture wicking polyester/33.3tex spandex coated yarn, the yarn material of the instep and toes is composed of 31.1tex ordinary polyester/33.3tex spandex coated yarn, and all parts of fabric stitch choose single-sided loop transfer stitch, the knitted sports shoes have the best thermal-moisture comfort.

Originality/value

The study used the thermal-moisture comfort foot model to simulate the human body metabolism and sweating system. Through the quantitative analyze of the thermal and moisture resistance of knitted upper fabrics to provide basis for the producers to design and product knitted sports shoes with good thermal-moisture comfort.

Details

International Journal of Clothing Science and Technology, vol. 30 no. 5
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 11 May 2012

Owen Thomas, Martin Wickham and Chris Hunt

The purpose of this paper is to present work on the incorporation of capacitors into printed circuit boards (PCB) as a method to measure moisture content and follow moisture

Abstract

Purpose

The purpose of this paper is to present work on the incorporation of capacitors into printed circuit boards (PCB) as a method to measure moisture content and follow moisture diffusion under ground planes.

Design/methodology/approach

PCBs were manufactured of FR‐4 incorporating different arrangements and sizes of capacitors formed between the tracks on adjacent layers of the PCB. The boards were placed in an 85°C and 85 per cent relative humidity (RH) environment to absorb moisture before baking at temperatures of 80, 110 or 125°C with the capacitance periodically measured. The effect of ground planes with different densities of plated and non‐plated through holes (PTH) has been studied by placing capacitors between ground planes.

Findings

Parallel plate capacitors embedded within a PCB showed a 10 per cent capacitance increase going from a dry state to being saturated with moisture in an 85°C and 85 per cent RH environment. The slow ingression of moisture under the capacitance planes meant that the measured capacitance change did not reflect the moisture content of the remainder of the board well. Capacitor plates with slots for the moisture to penetrate were also investigated, with the increase in capacitance found to show good correlation with the increase in board mass. In investigating moisture under ground planes, either by decreasing the hole density or by plating the holes, the time for moisture to diffuse out of the board was found to increase due to the lower exposed area on the PCB.

Originality/value

The paper illustrates a method that can be applied to PCB manufacturing to assess the moisture content of a board prior to reflow.

Details

Circuit World, vol. 38 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 25 May 2010

June Mitsuhashi and J.J. Morrell

Wetting wood plastic composites (WPCs) prior to testing can be challenging because of the inherent water repellency of the plastic. The purpose of this paper is to explore the use…

313

Abstract

Purpose

Wetting wood plastic composites (WPCs) prior to testing can be challenging because of the inherent water repellency of the plastic. The purpose of this paper is to explore the use of heating and wetting to accelerate moisture uptake on two WPCs.

Design/methodology/approach

Full size samples of the two WPCs were immersed in water at various temperatures or heated in an autoclave. Samples were removed periodically and dissected to determine the moisture profile by oven drying and weighing.

Findings

Moisture uptake is accelerated by heating, but the effect is mainly confined to the outer 5 mm of the samples. Moisture levels deeper in the samples are largely unaffected.

Research limitations/implications

Moisture uptake can be enhanced by heating, but the inability to increase moisture levels deeper in the wood suggests that tests assessing the role of moisture on WPC properties should use thinner specimens to ensure that moisture is well distributed in the materials.

Practical implications

The results suggest the need for a re‐evaluation of test methodologies for WPCs where moisture uptake is an integral part of the procedures to more closely align the methods to the WPC/moisture behaviour.

Originality/value

This paper will help researchers develop better methods for assessing the role of moisture in WPC behaviour.

Details

Pigment & Resin Technology, vol. 39 no. 3
Type: Research Article
ISSN: 0369-9420

Keywords

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 windy…

1236

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

Article
Publication date: 18 March 2024

Li Liu, Chunhua Zhang, Ping Hu, Sheng Liu and Zhiwen Chen

This paper aims to investigate the moisture diffusion behavior in a system-in-package module systematically by moisture-thermalmechanical-coupled finite element modeling with…

Abstract

Purpose

This paper aims to investigate the moisture diffusion behavior in a system-in-package module systematically by moisture-thermalmechanical-coupled finite element modeling with different structure parameters under increasingly harsh environment.

Design/methodology/approach

A finite element model for a system-in-package module was built with moisture-thermal-mechanical-coupled effects to study the subsequences of hygrothermal conditions.

Findings

It was found in this paper that the moisture diffusion path was mainly dominated by hygrothermal conditions, though structure parameters can affect the moisture distribution. At lower temperatures (30°C~85°C), the direction of moisture diffusion was from the periphery to the center of the module, which was commonly found in simulations and literatures. However, at relatively higher temperatures (125°C~220°C), the diffusion was from printed circuit board (PCB) to EMC due to the concentration gradient from PCB to EMC across the EMC/PCB interface. It was also found that there exists a critical thickness for EMC and PCB during the moisture diffusion. When the thickness of EMC or PCB increased to a certain value, the diffusion of moisture reached a stable state, and the concentration on the die surface in the packaging module hardly changed. A quantified correlation between the moisture diffusion coefficient and the critical thickness was then proposed for structure parameter optimization in the design of system-in-package module.

Originality/value

The different moisture diffusion behaviors at low and high temperatures have seldom been reported before. This work can facilitate the understanding of moisture diffusion within a package and offer some methods about minimizing its effect by design optimization.

Details

Soldering & Surface Mount Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 3 August 2023

Zuraihana Bachok, Aizat Abas, Hehgeraj A/L Raja Gobal, Norwahida Yusoff, Mohamad Riduwan Ramli, Mohamad Fikri Mohd Sharif, Fakhrozi Che Ani and Muhamed Abdul Fatah Muhamed Mukhtar

This study aims to investigate crack propagation in a moisture-preconditioned soft-termination multi-layer ceramic capacitor (MLCC) during thermal reflow process.

Abstract

Purpose

This study aims to investigate crack propagation in a moisture-preconditioned soft-termination multi-layer ceramic capacitor (MLCC) during thermal reflow process.

Design/methodology/approach

Experimental and extended finite element method (X-FEM) numerical analyses were used to analyse the soft-termination MLCC during thermal reflow. A cross-sectional field emission scanning electron microscope image of an actual MLCC’s crack was used to validate the accuracy of the simulation results generated in the study.

Findings

At 270°C, micro-voids between the copper-electrode and copper-epoxy layers absorbed 284.2 mm/mg3 of moisture, which generated 6.29 MPa of vapour pressure and caused a crack to propagate. Moisture that rapidly vaporises during reflow can cause stresses that exceed the adhesive/substrate interface’s adhesion strength of 6 MPa. Higher vapour pressure reduces crack development resistance. Thus, the maximum crack propagation between the copper-electrode and copper-epoxy layers at high reflow temperature was 0.077 mm. The numerical model was well-validated, as the maximum crack propagation discrepancy was 2.6%.

Practical implications

This research holds significant implications for the industry by providing valuable insights into the moisture-induced crack propagation mechanisms in soft-termination MLCCs during the reflow process. The findings can be used to optimise the design, manufacturing and assembly processes, ultimately leading to enhanced product quality, improved performance and increased reliability in various electronic applications. Moreover, while the study focused on a specific type of soft-termination MLCC in the reflow process, the methodologies and principles used in this research can be extended to other types of MLCC packages. The fundamental understanding gained from this study can be extrapolated to similar structures, enabling manufacturers to implement effective strategies for crack reduction across a wider range of MLCC applications.

Originality/value

The moisture-induced crack propagation in the soft-termination MLCC during thermal reflow process has not been reported to date. X-FEM numerical analysis on crack propagation have never been researched on the soft-termination MLCC.

Details

Soldering & Surface Mount Technology, vol. 35 no. 5
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 6 November 2017

Guanhui Wang, Lin Xiao, Tiantian Nan, Jin Jia, Haiying Xiao and Dongxing Zhang

This study aimed to investigate the collective effects of bending load and hygrothermal aging on glass fibre-reinforced plastics (GFRP) due to the fact that stress and water…

Abstract

Purpose

This study aimed to investigate the collective effects of bending load and hygrothermal aging on glass fibre-reinforced plastics (GFRP) due to the fact that stress and water absorption is inevitable during GFRP applications.

Design/methodology/approach

The water boiling method was used to study the moisture absorption, desorption behaviour and evaluate the performance of GFRP laminates under loading in this article. The moisture diffusion of laminates is characterized in three aging conditions (25°C, 45°C and 65°C water), along with three levels of bending load coefficients (0, 0.3 and 0.6). The moisture diffusion coefficients are determined through the curve fitting method of the experimental data of the initial process, based on the Fickian diffusion model. Moreover, the laminates’ performance is further discussed after adequate environmental aging and loading.

Findings

It was found that moisture absorption is promoted by the presence of bending load and boiling during this study. The absorption diffusion coefficient and moisture equilibrium content of the specimens increased with an increasing loading ratio and temperature. The bending strength of the laminate varied according to a contrary trend. Furthermore, the desorbed moisture content is found to be much higher after higher levels of bending load because it is harder to desorb the moisture in the interfaces and micro cracks.

Research limitations/implications

Collective effects of bending load and hygrothermal aging promote the absorption and result in accelerating property degradation of GFRP. It is significant to focus on these effects on the failure of GFRP.

Originality/value

A novel unit was designed to simulate the various loading acted on containers in this work.

Details

Pigment & Resin Technology, vol. 46 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 31 May 2022

Samridhi Garg, Monica Puri Sikka and Vinay Kumar Midha

Perspiration and heat are produced by the body and must be eliminated to maintain a stable body temperature. Sweat, heat and air must pass through the fabric to be comfortable…

Abstract

Purpose

Perspiration and heat are produced by the body and must be eliminated to maintain a stable body temperature. Sweat, heat and air must pass through the fabric to be comfortable. The cloth absorbs sweat and then releases it, allowing the body to chill down. By capillary action, moisture is driven away from fabric pores or sucked out of yarns. Convectional air movement improves sweat drainage, which may aid in body temperature reduction. Clothing reduces the skin's ability to transport heat and moisture to the outside. Excessive moisture makes clothing stick to the skin, whereas excessive heat induces heat stress, making the user uncomfortable. Wet heat loss is significantly more difficult to understand than dry heat loss. The purpose of this study is to provided a good compilation of complete information on wet thermal comfort of textile and technological elements to be consider while constructing protective apparel.

Design/methodology/approach

This paper aims to critically review studies on the thermal comfort of textiles in wet conditions and assess the results to guide future research.

Findings

Several recent studies focused on wet textiles' impact on comfort. Moisture reduces the fabric's thermal insulation value while also altering its moisture characteristics. Moisture and heat conductivity were linked. Sweat and other factors impact fabric comfort. So, while evaluating a fabric's comfort, consider both external and inside moisture.

Originality/value

The systematic literature review in this research focuses on wet thermal comfort and technological elements to consider while constructing protective apparel.

Details

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

Keywords

Open Access
Article
Publication date: 14 June 2019

Jesus David Gomez Diaz, Alejandro I. Monterroso, Patricia Ruiz, Lizeth M. Lechuga, Ana Cecilia Conde Álvarez and Carlos Asensio

This study aims to present the climate change effect on soil moisture regimes in Mexico in a global 1.5°C warming scenario.

1359

Abstract

Purpose

This study aims to present the climate change effect on soil moisture regimes in Mexico in a global 1.5°C warming scenario.

Design/methodology/approach

The soil moisture regimes were determined using the Newhall simulation model with the database of mean monthly precipitation and temperature at a scale of 1: 250,000 for the current scenario and with the climate change scenarios associated with a mean global temperature increase of 1.5°C, considering two Representative Concentration Pathways, 4.5 and 8.5 W/m2 and three general models of atmospheric circulation, namely, GFDL, HADGEM and MPI. The different vegetation types of the country were related to the soil moisture regimes for current conditions and for climate change.

Findings

According to the HADGEM and MPI models, almost the entire country is predicted to undergo a considerable increase in soil moisture deficit, and part of the areas of each moisture regime will shift to the next drier regime. The GFDL model also predicts this trend but at smaller proportions.

Originality/value

The changes in soil moisture at the regional scale that reveal the impacts of climate change and indicate where these changes will occur are important elements of the knowledge concerning the vulnerability of soils to climate change. New cartography is available in Mexico.

Details

International Journal of Climate Change Strategies and Management, vol. 11 no. 4
Type: Research Article
ISSN: 1756-8692

Keywords

Article
Publication date: 12 June 2018

T. Karthik, R. Murugan and Pandurangan Senthilkumar

Clothing must also assist the body’s thermal control function under changing physical loads in such a way that the body’s thermal and moisture management is balanced, and a…

Abstract

Purpose

Clothing must also assist the body’s thermal control function under changing physical loads in such a way that the body’s thermal and moisture management is balanced, and a microclimate is created next to the skin. One of the factors which affect moisture transport in a fabric is a fibre type. Hence, the purpose of this paper is to blend the natural hollow and low density fibre, milkweed, with cotton fibre at different proportions and to analyse and compare the influence of milkweed blend proportion on moisture management properties of rotor yarn fabrics with 100 per cent cotton fabric.

Design/methodology/approach

In the present study, cotton/milkweed blended rotor yarns were produced by using S-4 cotton variety and milkweed fibres in three different blend proportions such as cotton/milkweed 80/20, 60/40 and 40/60 along with 100 per cent cotton yarn with yarn count of 20 Ne. The single jersey knitted fabrics were produced with similar constructional parameters and then the fabrics were then scoured, bleached and neutralised as per the standard procedure. The fabrics have been analysed for its various moisture management properties using moisture management tester (MMT) and are statistically analysed.

Findings

The results indicate that, all the C/M blended fabrics have been classified as “moisture management fabric” and 100 per cent cotton fabric has been classified as “Fast absorbing and Quick Drying Fabric”. The overall moisture management capacity of C/M 40/60 fabric is excellent and could be used for summer, active and summer wear applications. One-way ANOVA analysis carried out at 95 per cent confidence level showed that the results are statistically significant. The pair-wise strength and association between various moisture management indices was analysed using Pearson correlation coefficient and observed that OWTC and OMMC was found to be positively and linearly related to each other.

Originality/value

The authors are confident that the cotton/milkweed blended yarns can be used as an inner wear and sportswear applications owing to the higher moisture regain and hollowness of milkweed fibre combined with the low packing density of C/M blended yarns which leads to overall improvement in moisture management properties of fabrics.

Details

International Journal of Clothing Science and Technology, vol. 30 no. 3
Type: Research Article
ISSN: 0955-6222

Keywords

1 – 10 of over 7000