As urban densification is leading to a steady growth of multi-family and mixed-use buildings, the need for high performance and cost-competitive sound insulation materials is increasing.
In addition, recent revisions in U.S. and Canadian standards for energy efficiency in buildings show a strong and growing demand for rigid insulation materials and occupants are increasingly demanding improved sound insulation made from more environmentally friendly products.
With that in mind, FPInnovations' Advanced Industrial Biomaterials group initiated a project aimed at assessing wood fibre insulation boards and building materials using cellulose filaments (CF) as an additive for enhanced insulation properties. The production of wet process wood fibre insulation board is a highly competitive domain where each company is looking to reduce costs by maximizing the properties of their board while potentially lowering density. As is the case with papermaking, where the high specific surface area of CF enhances the paper strength by increasing the number of fibre-fibre contact points in the sheet, a similar reinforcement mechanism by CF takes place in wood fibre boards.
Initial laboratory trials performed by FPInnovations have proven the potential of adding CF in wet process low-density fibreboard with respect to improved panel strength, lower panel density and higher thermal resistance. To confirm the commercial viability of CF, an industrial trial took place in a Canadian mill producing wood fibre insulation board—the trial involved adding CF during a typical grade production. The resulting boards showed improvements in tensile strength of up to 18%, flexural strength of up to 29%, compressive strength at 10% deformation of up to 59% and internal bond strength of up to 134%. In the trial, the ease of application and impact on machine runnability were also tested, while allowing the board density to increase by up to 11%. This initial trial was a first step towards the production of a lower density board product at equivalent strength; further adjustments to equipment and operation will be required for application at plant scale.
In the future, CF application may allow mill production of insulation boards having lower density and higher thermal resistance with equivalent strength. Further development is still required for analyzing the potential market and assessing the long-term influence of CF on machine runnability, however results have been promising so far.
FPInnovations is a not-for-profit world leader that specializes in the creation of scientific solutions in support of the Canadian forest sector's global competitiveness and responds to the priority needs of its industry members and government partners.