Declared value for the thermal conductivity coefficient of insulation corkboard

Abstract

This study presents the results of a set of tests for the determination of the thermal conductivity coefficient of samples extracted from boards of Insulation Corkboard (ICB) withdrawn from the usual production of the seven portuguese factories. These tests were carried out as a part of an interlaboratorial study integrated in the standardization program for cork of the sub-comission 4 of The National Technical Committee of Standardization (CT 16), in which participated the Cork Technological Centre (CTCOR), the National Laboratory of Civil Enginneering (LNEC) and the National Institute of Engineering and Industrial Technology (INETI). The purpose of this study aimed to contribute to the definition of the "declared value" of this thermal property to be included in the future European Standard (EN) specifying the characteristics of ICB for thermal insulating of buildings which is in preparation in the 88 Th Technical Committee of The European Committee of Standardization CEN/TC-88 (CEN 1995). In view of the results, the declared value of thermal conductivity proposed was 0.045 W/m. °C.

Experimental and finite element analysis of the impact response of agglomerated cork and its intraply hybrid flax/basalt sandwich structures

“…The huge influence of moisture can be explained considering that water is characterized by a thermal conductivity of 0.6 w/mK which is of one order of magnitude higher than cork and PVC foam ones. Similar findings were presented by Matias et al [164] and by Limam et al [165], who carried out their tests on black agglomerated cork considering the water content of the sample. The resistance value of insulation, R-value, is a parameter strictly interconnected to thermal conductivity and permits to define how well an insulating material can resist heat flow.…”

The Potential of Agglomerated Cork for Sandwich Structures: A Systematic Investigation of Physical, Thermal, and Mechanical Properties

“…For all materials, a decrease in thermal conductivity was registered for dried samples, and this can be ascribed to the fact that water has a thermal conductivity (0.6 W/mK) higher than cork and PVC by one order of magnitude. Similar results were obtained by Limam et al [15], who performed their tests on black agglomerated cork taking into account the sample water content, and by Matias et al [23].…”

Thermal Conductivity of Papua New Guinea Balsa Wood Measured using the Needle Probe Procedure

“…By comparison, the axial and tangential/radial direction has the highest mean TC of 0.0665 W/mK, which may be due to fibril alignment, air pockets, glue interference, and/or poor lamination between lumber, as evident in the end-grain sample results. Cha et al (2012) Insulation corkboard 0.045 Matias et al (1997) Plaster board 0.111 Cha et al (2012) Plywood 0.118 Cha et al (2012) Table 7 is a list of published TC values of various materials. Expanded polystyrene has the lowest TC value, making it a highly desirable insulation material.…”

“…The TC of insulation materials is affected by its density, porosity, moisture content, mean temperature difference, grain direction, and extractives content (Bootle 1983;Abdou and Budaiwi 2005;Yapici et al 2011). Matias et al (1997) further claimed that TC test results differ from lab to lab. Cai and Garrahan (2006) identified the TC of wood below 0 °C increases with moisture content, due to the presence of ice.…”