Fire Technology

, Volume 54, Issue 6, pp 1585–1608 | Cite as

Smouldering Combustion in Loose-Fill Wood Fibre Thermal Insulation: An Experimental Study

  • Anne Steen-HansenEmail author
  • Ragni Fjellgaard Mikalsen
  • Ulla Eidissen Jensen


A bench-scale experimental setup has been used to study the conditions necessary for smouldering ignition in four types of loose-fill wood fibre thermal insulation, and to study the development of the smouldering process. The products varied with regard to wood species, grain size and fire retardant chemical additives. The test material was placed in an insulated open top container and heated from below. Temperatures within the sample and mass loss were measured during the tests. Both the fibre size and the level of added fire retardant seem to influence the smouldering ignition. Two different types of smouldering were identified in this study. Materials undergoing smouldering Type 1 obtained maximum temperatures in the range 380°C to 440°C and a total mass loss of 40 wt% to 50 wt%. Materials undergoing smouldering Type 2 obtained maximum temperatures in the range 660°C to 700°C and a total mass loss of 80 wt% to 90 wt%. This implies that Type 2 smouldering involves secondary char oxidation, which represents a risk for transition to flaming combustion and thereby a considerable fire hazard. This has been an exploratory project and the results must therefore be considered as indicative. The findings may, however, have implications for fire safety in the practical use of loose-fill wood fibre insulation in buildings, and further experimental studies should be performed with this in mind to obtain more knowledge about the topic.


Fire Safety Smouldering combustion Wood fibre Loose-fill thermal insulation 



The authors want to thank the project management of the EMRIS (Emerging Risks from Smoldering Fires) project sincerely for the financial and scientific support for the project presented here. The EMRIS project is supported by the Research Council of Norway, Project 238329. The elemental and proximate analysis of the fuel given in Table 1 was provided by the group of Prof. Ulrich Krause at the Department of Process Safety and Environmental Engineering at Otto von Guericke University Magdeburg, Germany.


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  1. 1.RISE Fire Research TrondheimTillerNorway
  2. 2.Western Norway University of Applied Sciences (HVL)HaugesundNorway
  3. 3.Otto von Guericke University MagdeburgMagdeburgGermany
  4. 4.Norwegian University of Science and Technology (NTNU)TrondheimNorway

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