scholarly journals Water vapour permeability of wood – remarks on cup method procedure and measured data of spruce wood

2021 ◽  
Vol 2069 (1) ◽  
pp. 012009
Author(s):  
Jan Richter ◽  
Kamil Staněk
Keyword(s):  
Water Vapour ◽  
Measurement Method ◽  
Transverse Direction ◽  
Measured Data ◽  
Water Vapour Permeability ◽  
Wide Spread ◽  
Vapour Permeability ◽  
Laboratory Error ◽  
Spruce Wood ◽  
Measurement And Evaluation

Abstract Although the water vapour permeability of wood has been determined many times, there can be found a wide spread of values even related to only one wood specie and its single anatomical direction. This spread can possibly be attributed to the measurement method itself, since the cup method often shows high inter-laboratory error. However, even if the measurement and evaluation processes are well performed and under control, there were found several factors that can still highly affect the resulting value – up to ca. 70 %. These factors are neither mentioned in standards, nor were found in other sources. This paper theoretically describes those factors and their possible impact to the final value of water vapour permeability. Paper also presents one particular measurement scheme and obtained data from four cup tests performed on spruce wood in transverse direction.

Using Control Chart to Detect Abnormal Changes in the Permeability

2013 ◽  
Vol 779-780 ◽  
pp. 319-322
Author(s):  
Ming Hung Shu ◽  
Jui Chan Huang ◽  
Thanh Lam Nguyen ◽  
Bi Min Hsu
Keyword(s):  
Water Vapour ◽  
Average Run Length ◽  
Stable Process ◽  
Critical Factor ◽  
Water Vapour Permeability ◽  
Control Signal ◽  
Process Mean ◽  
Vapour Permeability ◽  
Practical Applications ◽  
Printing Papers

Water-vapour permeability is a critical factor of writing/ printing papers in most of practical applications; but how to monitor the manufacturing process to keep the key characteristic of the paper in control is still understudied. Therefore, in this paper, in order to monitor the water-vapour permeability of writing/ printing papers, MaxGWMA chart is first suggested due to its best effectiveness in terms of average run length performance and its high capability of detecting small shifts in the process mean and variability as well as identifying the source and the direction of an out-of-control signal. By using MaxGWMA chart, assignable causes of any out-of-control signal should be deeply examined so as to have proper corrective actions undertaken to either eliminate them from the process or reduce the variability induced by them to make the papers consistently manufactured under a stable process.

scholarly journals Hygrothermal simulation of building performance: data for Scottish masonry materials

2021 ◽  
Vol 54 (4) ◽  
Author(s):  
P. F. G. Banfill
Keyword(s):  
Thermal Conductivity ◽  
Water Vapour ◽  
Material Properties ◽  
Simulation Software ◽  
Water Vapour Permeability ◽  
High Porosity ◽  
Water Absorption Coefficient ◽  
Vapour Permeability ◽  
Hygrothermal Simulation ◽  
Current Production

AbstractRetrofitting thermal insulation to solid masonry walls alters their hygrothermal behaviour, which can be modelled by hygrothermal simulation software. However, such software needs values of key material properties to ensure satisfactory results and until now data has not been available for Scottish masonry buildings. This work aims to contribute to a Scotland-specific dataset of material properties for use by designers working on such buildings. Thermal conductivity, water vapour permeability, sorptivity, water absorption coefficient, hygroscopic sorption, density and porosity were all determined experimentally for selected historic and contemporary masonry materials. Within the range of materials tested three groups of materials properties emerge. Natural hydraulic lime mortars, hot-mixed quicklime mortar and earth mortar all show comparatively low density, high porosity, low thermal conductivity, high water vapour permeability and variable but generally high hygroscopic sorption. Craigleith, Hailes and Giffnock sandstones, no longer available but obtained from conservation works on historic buildings, and Locharbriggs and Hazeldean sandstones, obtained from current production, all show intermediate values of these properties. Crathes granodiorite and Scottish whinstone (from current production) show high density, low porosity, high thermal conductivity, low water vapour permeability and low hygroscopic sorption. It is shown that these materials are all relevant to Scottish buildings constructed in traditional masonry and this paper presents the first comprehensive set of hygrothermal property data for them.

Effect of resin hydrophilicity on water-vapour permeability of dental adhesive films

2005 ◽  
Vol 113 (5) ◽  
pp. 436-442 ◽  
Author(s):  
Nigel M. King ◽  
Noriko Hiraishi ◽  
Cynthia K. Y. Yiu ◽  
Edna L. Pashley ◽  
Robert J. Loushine ◽  
...  
Keyword(s):  
Water Vapour ◽  
Water Vapour Permeability ◽  
Vapour Permeability ◽  
Dental Adhesive
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