Methods for determining thermal insulating properties. Tests for thermal conductivity and related properties

2015 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulating ◽  
Insulating Properties

Wrong expectation of superinsulation behavior from largely-expanded nanocellular foams

Nanoscale ◽  
2020 ◽  
Vol 12 (24) ◽  
pp. 13064-13085 ◽  
Author(s):  
Piyapong Buahom ◽  
Chongda Wang ◽  
Mohammed Alshrah ◽  
Guilong Wang ◽  
Pengjian Gong ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Insulation ◽  
Cellular Structure ◽  
Thermal Insulating ◽  
Insulating Properties

This work aims to predict the thermal conductivity of microcellular and nanocellular thermal insulation foams to explore the correlation between the cellular structure and the thermal insulating properties.

Sustainable materials with high insulation capacity obtained from wastes from hemp industry processed by wet-laid

2021 ◽  
pp. 004051752110460
Author(s):  
O Gutierrez-Moscardo ◽  
M Canet ◽  
J Gomez-Caturla ◽  
D Lascano ◽  
E Fages ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Textile Industry ◽  
Areal Density ◽  
Absorption Capacity ◽  
Thermal Insulating ◽  
Viscose Fibers ◽  
Sustainable Materials ◽  
The One ◽  
Insulating Properties

This article reports on the revalorization of hemp waste from the textile industry, focusing on the development of new sustainable materials with high insulating properties. Wet-laid technology was used to manufacture nonwovens with different binding fibers, polylactic acid, and viscose fibers. The characterization of the acoustic insulating capacity was carried out using a Kundt tube, and the thermal insulating performance by measuring the heat transmission resistance ( R) and thermal conductivity ( λ). The results showed that the developed nonwovens have lower thermal conductivity values of about 0.027–0.034 W/(m K), were even lower than those of traditional thermal insulating materials, being the sample with 100 g/m2 of areal density and with a composition of 80% of hemp, 10% of polylactide and 10% of viscose the one with the lowest thermal conductivity (0.027 W/(mK). Their acoustic absorption capacity was around 0.76 at a frequency of 6 kHz, in samples containing high hemp waste (>80 wt%). However, the heterogeneous, discontinuous, and high void density structure that contributes to excellent insulating properties, lead to a decrease in their mechanical properties. This demonstrated that these materials are suitable for substituting traditional materials in insulating applications. Additionally, antifungal tests were carried out. However, hemp nonwovens proved to be inefficient against fungal proliferation.

Synthesis and characterization of geometrically tunable nano-size hollow silicate particles and their dip-coating prepared films for thermal management applications

RSC Advances ◽  
2015 ◽  
Vol 5 (126) ◽  
pp. 104408-104416 ◽  
Author(s):  
Raymond V. Rivera Virtudazo ◽  
Ye Lin ◽  
Rudder T. Wu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Management ◽  
Dip Coating ◽  
Synthesis And Characterization ◽  
Thermal Insulating ◽  
Set Up ◽  
Insulating Properties ◽  
Nano Size ◽  
Xenon Flash

The thermal insulating properties of NHSPs were demonstrated by coating glass with NHSPs. A reduction of approximately 29.9% in thermal conductivity was observed, which was evaluated by a contactless approach using a xenon flash lamp set-up.

Thermal Insulating Alkali-Activated Materials with Lightweight Aggregate

2014 ◽  
Vol 897 ◽  
pp. 69-72 ◽  
Author(s):  
Jana Boháčová ◽  
Stanislav Staněk ◽  
Pavel Mec
Keyword(s):  
Thermal Conductivity ◽  
System Development ◽  
Lightweight Aggregate ◽  
Laboratory Research ◽  
Building Industry ◽  
Low Density ◽  
Practical Application ◽  
Thermal Insulating ◽  
Insulating Properties ◽  
Alkali Activated

The paper deals with laboratory research and development of alkali activated system with thermal insulating properties where low density materials are used. The experiment is focused on strength and heat conductivity of prepared substances. In research five kinds of mixtures were prepared. The values of compressive strength and thermal conductivity of tested admixtures qualitatively correspond to commercially available building material. Results are foundations for next lightweight alkali activated system development and research focused on practical application in building industry.

Determination of Thermal Conductivity on Lightweight Concretes

2016 ◽  
Vol 677 ◽  
pp. 163-168
Author(s):  
Lenka Bodnárová ◽  
Jitka Peterková ◽  
Jiri Zach ◽  
Kateřina Sovová
Keyword(s):  
Thermal Conductivity ◽  
High Temperatures ◽  
Structural Changes ◽  
Lightweight Concrete ◽  
Thermal Insulating ◽  
Coefficient Of Thermal Conductivity ◽  
The Matrix ◽  
Wire Method ◽  
Insulating Properties

A range of testing methods were used to study the potential structural changes as a result of the effects of high temperatures on lightweight types of concrete developed above all for fire resistant structures. One such test for monitoring changes in concrete structures is the non-stationary determination of the coefficient of thermal conductivity using the hot wire method. The matrix structure progressively collapses as a result of the effects of high temperatures on the concrete structure ́s surface because erosion takes place of the matrix and aggregate porous structures. The degradation of the porosity of the concrete results in the deterioration of its thermal insulating properties. This paper assesses the dependence of the thermal conductivity coefficient of lightweight concretes on temperature and determines the potential occurrence of structural changes in the lightweight concrete matrix. The results were verified using other methods to determine the concrete ́s resistance to thermal load.

scholarly journals Thermal Insulating Properties of Straw-Filled Environmentally Friendly Building Materials

2017 ◽  
Vol 13 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Rositsa Petkova-Slipets ◽  
Penka Zlateva
Keyword(s):  
Thermal Conductivity ◽  
Composite Materials ◽  
Energy Efficient ◽  
Building Materials ◽  
Thermal Conductivity Coefficient ◽  
Environmentally Friendly ◽  
Thermal Insulating ◽  
Insulating Properties ◽  
Thermal Physical Properties

AbstractThe paper presents results of a research for determination of a few general thermal-physical properties of environmentally friendly building materials made by clay, sand and straw. The aim of this study is to establish their heat insulating and energy-efficient capacity. All specific measurements were carried out by using the newest generation thermal conductivity analyser Mathis TCi.The results showed that the studied composite materials are good thermal insulators with thermal conductivity less than 0.5 W/m.K, which depends on the straw amount. Even less than 0.5 wt.% straw reflects on the insulating properties by decreasing the thermal conductivity coefficient with nearly 50 %.

scholarly journals Development of Wood-Crete from Hardwood and Softwood Sawdust

2013 ◽  
Vol 7 (1) ◽  
pp. 108-117 ◽  
Author(s):  
Eboziegbe Patrick Aigbomian ◽  
Mizi Fan
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Compressive Strength ◽  
Wood Species ◽  
Strength Properties ◽  
Particle Sizes ◽  
Wood Sawdust ◽  
Thermal Insulating ◽  
Structural Applications ◽  
Insulating Properties

Wood-crete, a new building material has previously been developed from sawdust, inorganic binder and addition of waste paper, finding its use mainly for wall panelling or other non- and semi-structural applications with good thermal insulating properties. In this study, the properties of wood-crete were investigated based on the type of wood sawdust – hardwood (beech and oak) and softwood (pine and cedar). The results showed that (1) the compressive strength of wood-crete was closely related to the wood species, with the compressive strength of 3.93MPa being for hardwood wood-crete compared to 1.37MPa and 0.26MPa of wood-crete from softwood and mixed wood respectively; (2) wood-crete from hardwood sawdust had a higher density than those made from softwood sawdust and mixed wood; (3) particle size had a significant influence on the strength properties and density of wood-crete with wood-crete made from 1mm particle size recording a higher compressive strength and density compared to 2mm and 3mm particle size. The optimum size for wood-crete was dependent on the wood species; (4) thermal conductivity of wood-crete was closely related to the chemical composition of various wood species, with softwood wood-crete having about 20% lower thermal conductivity compared to hardwood wood-crete; (5) a ratio of 1:2 of sawdust to binder was found advisable for the production of wood-crete for various wood species and particle sizes investigated. The compressive strength of wood-crete made from sawdust of both softwood and hardwood was similar to or higher than that of hempcrete, indicating their suitability for wall panelling or other non- and semi-structural applications. The results of this study provide an important foundation for choosing what wood species, particle sizes and combinations of sawdust to be used for the production of wood-crete.

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