Water Repellency/Proof/Vapor Permeability Characteristics of Coated and Laminated Breathable Fabrics for Outdoor Clothing

This study examined the water repellency (WR), waterproof, and water vapor permeability (WVP) characteristics of twelve types of laminated and coated woven fabrics for outdoor clothing. These characteristics were compared with the fabric structural parameters, such as cover factor, thickness, and weight, and surface modification (finishing) factors, such as coating, laminating, and Teflon treatments. In addition, an eco-friendly process for surface modification was proposed followed by a summary. Superior waterproof-breathable characteristics with 100% water-repellency were achieved in specimen 3 in group A by treatment with a hydrophilic laminated finish using nylon woven fabric with a cover factor between 0.7 and 0.9 in a 2.5-layered fabric, which was the best specimen with waterproof-breathable characteristics. A high WVP in the coated and laminated fabrics was observed in the fabrics with a low weave density coefficient (WDC) and low thickness per unit weight of the fabric, whereas superior water repellency and waterproof characteristics were observed in the high-cover-factor (WDC) fabric with appropriate fabric thickness. The determination coefficient (R2) from regression analysis between the WVP and fabric structural parameters indicated a higher contribution of the fabric structural parameters than surface modification factors, such as coating and laminating to the WVP in the coated and laminated fabrics. Furthermore, the cover factor was the most important factor influencing the WVP of the waterproof-breathable fabrics. Of twelve coated and laminated fabrics, the laminated nylon and nylon/cotton composite fabrics showed superior WVP with high WR and waterproof characteristics. Accordingly, based on the WR, waterproof, and WVP characteristics of the coated and laminated breathable fabrics, the laminating method, as an eco-friendly process, is recommended to obtain better waterproof-breathable fabrics.

Improving the ultraviolet protection factor of textiles through mechanical surface modification using calendering

The textile modification technique of calendering was used to change the cover factor of wearable textiles in order to improve the ultraviolet protection factor and decrease the amount of ultraviolet radiation transmitted through the fabric. Using optical microscopy and ultraviolet spectrophotometry, the quantifiable changes that occurred after repeated passes through the calender were measured. It was found that after one pass the uncovered area decreased by a factor of two and the ultraviolet protection factor increased by 200%. The thickness and air permeability of treated fabric decreased with repeated calendering. The bending stiffness remained nearly unchanged, and thus the mechanical properties were not altered substantially by the fabric compression.

Case Study of Load Matching and Energy Cost for Net-Zero Energy Houses in Korea

Over the past 20 years, net-zero energy house (NZEH) construction costs have steadily decreased because of many reasons, such as technical progress, energy-saving design obligations, and dramatic cost reductions in renewable energy systems, especially solar power systems. Currently, the costs of NZEH are estimated to be about 5% higher than similar-sized houses. These additional costs are mainly for installing PV systems, which can be offset by energy saving costs. This study assessed energy performance and load matching through remote monitoring systems, and energy costs were analyzed for two-family houses. The two houses were all-electric houses and different in both size and location. A 6 kWp grid-connected PV system and 16 kW air source heat pump for space heating and domestic hot water were equally implemented. After data analysis, 100% of the energies were supplied through the PV system for 3 years, thus achieving net-zero energy. According to the Korean residential electricity tariff system, the annual electricity charges were, on average, between USD 105.1 and USD 121.4 after adding demand charges and value-added tax for import electricity charges. The energy cost reduction rate, compared to the same house without a PV system, was about 95%, and the simple payback period of the 6 kW PV system in NZEH was about 6 years. In addition, the annual load cover factor and supply cover factor as load-match indices between electricity generation and the load were in a range of 0.39–0.49 and 0.37–0.42, respectively.

Modelling of Consumption Shares for Small Wind Energy Prosumers

This article describes a simulation of energy distribution in an average household where electricity is produced with a small wind generator or purchased from the public electricity grid. Numerical experiments conducted within an average of five minutes were performed using annual production and consumption graphs. Virtual storage devices, a water tank and a battery were used to buffer energy inside the household. The energy required for non-shiftable consumption and hot water consumption were taken directly from the utility grid. Surplus energy remaining from wind generator production after providing for consumption and storage needs were redirected there. A cover factor was used as a measure of the efficiency of energy distribution. One of the aims of the article was to determine by simulations the change of the cover factor in a virtually designed situation where the expected energy output of the wind generator was known in advance over one to three hours. The results found that for the configuration of the proposed nanogrid option, the positive results were readily achieved when the expected wind generator production was known an hour ahead. Then, the cover factor increased from 0.593 to 0.645. The side result of using projected/expected production is an increase in asymmetrical energy exchanges bilaterally between nanogrid and utility grid in favour of grid sales. Another finding was that the cover factor depended on the wind generator's production intensity but less on the intensity of consumption within the household.It is hoped/expected that future research will address the prediction of output using mathematical methods.

Use of Extended Cover Factor Theory in UV Protection of Woven Fabric

The paper presents an extension of existed cover factor theory more suitable for the evaluation of light penetration through a net woven fabrics structure. It also introduces a new simplified model of predicting the ultraviolet (UV) protective properties of woven fabrics assuming that the coefficient of reflection (KR), transmission (KT), and absorption (KA) of constitutive yarns are known. Since usually they are not, the procedure of preparation of simulation of proper woven fabric samples without interlacing and with known constructional parameters is also presented. The procedure finishes with a fast and cheap detection of missed coefficient for any type of yarns. There are differences between theoretical and measured results, which are not particularly significant in regard to the purpose and demands of investigation.

Qualitative and quantitative evaluation of text printed with flexography on woven labels

Even though textile labels are not often the subject of research, their quality must not be neglected. Printed typographic elements (i.e. letters and texts) must be visible regardless of textile ribbons and typeface or type size to be printed. Thus, the aim of the research was to qualitatively and quantitatively analyze and evaluate the text printed with flexography in two different typefaces (Helvetica and Verdana) in three different type sizes (4, 6 and 8 point) on five textile ribbons made of polyester and polyester/cotton mixture in two different weaves (plain and satin). The results of our research showed that the quality of printed letters is influenced by the properties of textile ribbons as well as by the chosen typographic features. When textile ribbons were composed of polyester filaments, the quality of prints was better than in the case of the mixed composition with cotton fibers. The coating and previously dyed textile ribbons had a positive influence on the quality of printed letters. The typeface Verdana gave more distinct and contrasted printed letters than Helvetica. The quality of printed letters (measured by the cover factor) decreased with the reduced type size; letters (and text) in a smaller type size (4 point) were hence, depending on the properties of textile ribbons, less visible.

MODELING OF WATER EROSION IN A SUB-BASIN IN RIO GRANDE DO SUL USING THE RUSLE MODEL

The intense use of farming land has caused many consequences to the environment, among them, water erosion. The scale study of river basins through modeling allows the identification and estimation of soil losses, aiming at the conservationist planning of the site. The objective of this work was to predict soil loss in the Micaela sub-basin, with an area of ??37 km2 located in the municipality of Pelotas, Rio Grande do Sul. For the prediction of soil loss, the Revised Universal Soil Loss Equation (RUSLE) was used. Erosivity was obtained from data from the literature and erodibility was estimated by means of the inherent soil attributes and the topographic factor calculated according to the accumulated flow and declivity in each pixel. For the cover factor, data from the literature were used, according to use recommendation and existing soil cover. The study area shows a strong erosivity, which ranged from 8,045 to 8,833 MJ mm ha-1 h-1 year-1. The Argissolos occupy 81.31% of the sub-basin and present high erodibility, varying from 0.0369 to 0.0422 Mg ha h ha-1 MJ-1 mm -1. The sites with the largest vegetation cover were those with the lowest soil losses. However, in more than 36% of the area, the soil losses are above the tolerable therehsold, indicating that they are more prone to degradation and, therefore, the systems of land use and adopted management should be reviewed.

Effects of Micro-Braiding and Co-Wrapping Techniques on Characteristics of Flax/Polypropylene-Based Hybrid Yarn: A Comparative Study

Micro-braiding and co-wrapping techniques have been developed over a few decades and have made important contributions to biocomposites development. In this present study, a set of flax/polypropylene (PP) micro-braided and co-wrapped yarns was developed by varying different PP parameters (PP braiding angles and PP wrapping turns, respectively) to get different flax/PP mass ratios. The effects on textile and mechanical characteristics were studied thoroughly at the yarn scale, both dry- and thermo-state tensile tests were carried out, and tensile properties were compared before and after the braiding process to study the braidabilities. It was observed that PP braiding angles of micro-braided yarn influenced the frictional damage on surface treatment agent of flax roving, the cohesive effect between PP filaments/flax roving, and the PP cover factor; PP wrapping turns of co-wrapped yarn had a strong impact on the flax roving damage and the PP coverage, which further influenced the characteristics. Micro-braided yarn and co-wrapped yarn with the same flax/PP mass ratio were compared to evaluate the two different hybrid yarn production techniques; it was proven that micro-braided yarn presented better performance.

Study on pilling performance of polyester-cotton blended woven fabrics

Aiming at the classic problem of pilling of polyester-cotton blended woven fabrics, pilling grades were evaluated by image analysis method to study the effects of yarn twist, spinning method, warp, and weft density, fabric cover factor and fabric singeing on pilling performance. The length and density distribution of fabric hairiness was studied by Nano measurer software. The respective roles of polyester and cotton fibers were studied by using scanning electron microscope and quantitative chemical analysis method. The experimental results showed that the factors for the best anti-pilling fabric are that yarn twist is 950 N/m, the spinning method is siro-compact spinning, warp density is 394 N/10cm, weft density is 265 N/10cm, fabric cover factor is 103.9%, and fabric should be singed. Cotton hairiness is fractured, which is wrapped by polyester hairiness to form pills. The frequency distribution of hairiness is approximately given by Gauss distribution. Mass ratio of polyester and cotton hairiness is nearly 66%/34%.