Papers by Keyword: Moisture Permeability

Abstract: One of the basic measures of energy efficiency in residential buildings is the reduction of heat and coolant pressure, when external structures - walls, ceilings - contain thermal insulation material, as a result of which heat and cold losses are reduced, as a result of air-and moisture permeability. Their number is largely determined by the climatic zone of the building, construction, sources of heat and cold, fuel and electricity prices in this region. In such practice, first of all, attention is paid to the problems of the optimal thickness of the thermal insulator, the installation location, since improper installation in the structure can cause water condensation, which will lead to partial wear of the structure, since the properties of reinforced-concrete layers will deteriorate. This concerns the peculiarities of carrying out thermal insulation works and their necessity both in under construction and in buildings in use. However, even in these conditions, when discussing the thermal effect of thermal insulation on structures, due attention is not paid to individual structures, especially walls, moisture problems. Consideration of insulators with more or less efficient energy and heat engineering characteristics, when it was found that there is a significant difference between their results and effects, aroused particular interest in the study of the problem. This is followed by a study of the influence of the presence of thermal insulation in the structure on the cold load required for cooling, revealed a pattern of cost changes in the case of insulating materials with more or less properties - foam.

Abstract: This article about the moisture permeability test system of fire taking five outer fabric and five kinds of multi-layer fabric. Screening of fire suit multi-layer fabrics system, the water vapor permeability and fabric structure parameters of correlation analysis. The experimental results showed that, 3 # multi-layer fabric system is the best choice of the fire fighting service; Fabric thickness and i the square meter gram weight is inversely proportional to the fabric moisture permeability relationship; For the effect of PTFE membrane laminated fabric to fabric itself can also through the amount of water vapor has certain influence. While ensuring waterproof, Moisture permeability fabric may be appropriate to increase the resistance, in order to protect the user's comfort.

Abstract: In this article, the changes of the polyvinyl chloride (PVC) film properties and its law are analyzed during the ultraviolet and thermal aging. Using accelerated aging methods in laboratory,it was found that the tensile strength by ultraviolet aging fell down, on the contrary, it raised by thermal aging. This result indicate that PVC film was not aged to reduce the tensile strength at 50°C for 120h.We found the air permeability curves rose firstly then to decline, and the moisture permeability of PVC film curves declined by the two aging methods. The effects of the ultraviolet aging on the air and moisture permeability were a marked decrease.

Abstract: Most of UV protection textiles are made of chemical fibers, and a large part of them have poor air permeability and moisture permeability, which influences the wearing comfort. This work blended polyester and linen to produce a new kind of knitted fabric and tested the fabric structures, air permeability, moisture permeability and UV value. Excel and SPSS were used to compare the properties of new knitted fabrics and find out the relationships between the constructional parameters and properties. The results indicated that there are regression equations between constructional parameters and properties and got a new kind of UV protection fabric with good air permeability and moisture permeability.

Abstract: Take liquid phase separation method to prepare polyurethane microporous membrane. In the preparation of microporous membrane process phosphorus add modification flame retardant agent in order to improve the polyurethane flame retardant properties. Experiments prove that the add of flame retardant can increase the flame retardant performance of polyurethane greatly. when phosphorus add quantity of flame retardant agent for 8 % polyurethane microporous membrane flame retardant was the best effect. And microporous membrane other performance also have no obvious effect. Because of flame retardant performance was good, this kind of polyurethane can be widely used in floor synthetic leather, wall paper, decoration, etc.

Abstract: To study the influence of structure parameters on moisture permeability of fabric woven by fine pp fiber with star section, nine fabrics with different structure and tightness had been woven for experiment, and a moisture permeability test with moisture absorbtion method was performed and compared for these fabrics. Some conclusions are obtained: the moisture permeability showed direct correlation with fabric texture and tightness. It will be improved as the the float of weave get longer. Moreover it will decline with the increasing of fabric tightness and showed significant correlation with Polynomial function when the results fitted with it.

Abstract: A kind of SMS composite nonwovens with excellent antistatic property was developed by mixing the polypropylene resin and the antistatic agent. Mechanical property, air permeability, drapability and antistatic property of the products at different antistatic agent content were analysed. The results show that the antistatic property of SMS composite nonwovens was improved significantly by blending antistatic agent, Although the mechanical property, drapability and permeability is deceased slightly.

Abstract: Moisture permeability is an important property of cotton fabrics. Fully understanding of cotton fabric moisture absorption and moisture permeability plays an important role in the further study of the cotton fabric property and development of new cotton fabric. According to 6 kinds of cotton fabrics, the moisture permeability was measured by wet cup moisture absorption method under normal temperature. Such structural parameters have been analyzed as the yarn density, warp and weft density, weight per square meters, thickness, twist, which influenced the moisture permeability of fabrics. By the grey relational analysis, the grey relational sequence of structural parameters have been concluded which affect the moisture permeability of fabrics: thickness>weight per square meters>weft density>weft twist>warp density>wefts yarn density>warp twist>warp yarn density. The results provide theoretical basis for research and designing of textile products and modification of fabrics.

Abstract: Multiphase, segmented polyurethanes with mixed soft segment phase were prepared from 4,4’- diphenylmethane diisocyanate (Pure MDI), polybutylene adipate (glycol) 2000 (PBA2000) and polyethylene glycol 1000 (PEG1000) with 1,4-butanediol (BDO) as the chain extender. Further more, the relationships between domain separation structure, crystallizability of soft segment and moisture permeability, hydrophilic property, phase inversion temperature (PIT) of the polyurethanes were investigated. The studies show that the chemical structure, concentration of hydrophilic soft monomers and the microphase separation degree of the mixed soft segments from hard segment domain have remarkable effects on the application properties of polyurethane.

Abstract: In order to prepare a time decay-resistant electromagnetic shielding (ES) fabric with good handle, moisture permeability and antibacterial properties, Cu, Ag, Ag/Cu and Ag/Cu/Ag films were deposited on PET non-woven by sputtering in screening experiment. Considering the post continues processing, this study focuses on discharge parameters optimum for a limited short time. Relationship was studied between deposited rate and ES effectiveness (ESE) for the four metallic films on various substrates. The metal deposit greatly relays on the chemical nature of the substrate and target metal category. The deposited metal rate on metal is larger than that on PET. In comparison with single metallic film, the dB value of multi-metallic film obtained for same time even for more time remarkably dropped. Therefore, an Ag-coated PET no-woven was finally fabricated as the multi-functional fabric with anti-decay ESE. The multi-functional PET no-woven with good handle obtained for 3min. by optimizing other parameters exhibits higher ESE, good anti-bacterial and moisture permeability.