Erik Larnøy
Forsker
Sammendrag
The study investigated the production process and properties of a new wood-based material called Bioblocks. This sustainable composite is made from medium-density-fibreboard (MDF) residues, citric acid and either sorbitol or hexanediol. The process involves mixing in-water diluted chemicals with the MDF residues and curing the mixture in a laboratory oven to esterify the sorbitol and wood components with citric acid. A design of experiment was used to determine the influence and optima of the different process factors, and an optimised trial further investigated the material properties. The density distribution, compression strength, and TS after 24 h immersion in water according to EN 317 of the Bioblocks were tested. The first trial showed that mainly the amount of water added impacts the product’s properties. The optimised material achieved a sufficient density distribution with an average density of about 420 kg/m3, a compression strength of up to 3.5 N/mm2, and a TS of about 2%. Therefore, Bioblocks are a promising natural material to use waste MDF and substitute fossil, unsustainable materials.
Forfattere
Stephen Amiandamhen Synne Strømmen Ingeborg Olsdatter Ohren Nordraak Andreas Treu Erik LarnøySammendrag
This study investigated the potential of wood particles from Ciol®-treated wood in particleboard production. Ciol® is a renewable formulation from water, citric acid, and sorbitol, which has been commercially developed as a promising alternative for wood modification. Radiata pine wood was impregnated with 60% and 85% concentrations of the Ciol® solution for 150 mins. The impregnated boards were cured and subsequently planned. Particleboards were thereafter produced from the wood shavings using urea formaldehyde (UF) and melamine urea formaldehyde resin (MUF). The boards were produced with or without the use of ammonium nitrate as a hardener. The wood particles and produced boards were characterized via analytical techniques and standard test methods. The effect of Ciol® treatment and its concentration on the properties of the shavings and the particleboards was investigated as well as the effect of the resin type on the panel properties. The use of MUF without the hardener gave the best bending strength of 13 N/mm² and modulus of elasticity of 3187 N/mm². However, there was no significant difference in the results obtained when the hardener was added to MUF resins. Recycling Ciol®-treated wood shavings in particleboard production proved to be a promising approach with MUF resins.
Sammendrag
Phenol-formaldehyde (PF) resins can be impregnated and cured in situ to improve the woods dimensional stability and decay resistance. In search of renewable alternatives, the substitution of phenol by lignin cleavage products (LCP) has been discussed. However, the different chemical nature may affect the performance of the resin against fungal decay, formaldehyde emission, and equilibrium moisture content. In this study, 30 % (w/w) of the phenol in PF resins were substituted by LCP obtained from microwave-assisted pyrolysis. Scots pine sapwood was modified with the resin. The decay resistance against Rhodonia placenta, Gloeophyllum trabeum, and Trametes versicolor was determined. Additionally, effects of specimen organisation within the Petri dish, different substrates, length of leaching, and type of inoculum were studied. Further, the materials water vapor sorption properties and formaldehyde emission were determined. All modifications effectively reduced fungal decay. With 10 % weight percent gain (WPG), initial decay was detected, while 20 % WPG and 30 % WPG provided efficient protection. The substitution of phenol increases the formaldehyde emission. While further reduction in formaldehyde in the resin admixture or formaldehyde scavengers may be required, the method described herein can be used to partly replace fossil-based phenol, while maintaining good fungal resistance.
Divisjon for skog og utmark
Circular use of wood for increased sustainability and innovation (circWOOD)
circWOOD will investigate aspects of wood use in the Norwegian economy, with particular emphasis on the reuse of wood in construction projects, and recycled wood as raw material in today's wood industry.
Divisjon for skog og utmark
Sirkulær bruk av tre for økt bærekraft og innovasjon (CircWOOD)
CircWOOD skal undersøke aspekter ved trebruk i den norske økonomien, med særlig vekt på ombruk av returtre i byggeprosjekter, og returtre som råstoff i dagens treindustri.
