Improving the performance of wood products
One of Scion's focusses is modifying the properties of a wide range of woods to expand the applications and places where wood products can be used.
Materials science, engineering and technology
Biological processes influence the chemical composition and structure of wood and affect properties such as strength, stiffness and how wood interacts water.
Understanding these interactions allows us to use chemistry, biology and physics to alter material properties and design materials with new performances and behaviours.
Drying, thermal, chemical and other treatments can improve the stability, durability, structural performance and appearance of wood, expanding the applications and markets for wood products.
Drying wood using heat
Drying reduces the moisture content of wood to prevent distortion, shrinkage or other problems during use. Controlled kiln or oven drying allows wood processors to increase throughput and have better control over the final moisture content, improving product quality and value. Scion has more than 50 years of experience working with manufacturers to develop drying techniques for radiata pine.
Read about our expertise in softwood drying [pdf]
Heating timber to 160-260°C in the absence of oxygen (torrefaction) causes permanent changes in the chemical composition of wood that improve timber durability and performance. We are investigating the changes that occur to understand how they affect timber properties and to optimise torrefaction conditions.
We are working on the thermal modification of radiata pine, eucalyptus and other species including tōtara.
Dewatering or supercritical CO2 extraction
Carbon dioxide behaves as a gas and a fluid under supercritical conditions and can be used to extract water and other compounds from wood cells. The dewatering process does not affect the final wood quality. The dewatered wood can undergo further chemical modifications to produce high value wood products.
Scion’s supercritical CO2 dewatering pilot plant produces dewatered material for both research and to assist those who wish to use technology to develop and evaluate prototype products.
Modifying wood chemically
Chemicals that penetrate wood can bind to reactive portions of the cell walls. In some cases, the introduced chemical can polymerise in situ. Chemical modification can greatly improve dimensional stability, resistance to decay and pests and change wood colour, allowing wood to be used in a wide range of applications.
We concentrate on understanding what is happening in wood cells, developing processes to remove water, introduce chemicals and get them to stay in the wood cells, as well as characterising the resultant timbers.
Increasing wood resistance to decay and insects: wood preservation
Bio-based wood preservatives and carrier systems are alternatives to chemical wood preservatives such as copper chrome arsenic (CCA), which is restricted in certain export markets and unacceptable to many consumers. We are identifying and testing natural compounds with positive anti-fungal properties to achieve H3 hazard protection for wood used in window and exterior door joinery.Listen to Tripti Singh talking about bio-based timber preservative (RadioNZ)
Novel research by our wood preservation team led to treatments for partially degraded framing in "leaky buildings" that alleviated the necessity of fully replacing wood when carrying out repairs.
Industry standard and testing protocols
Scion is a member of New Zealand Timber Preservation Council and Scion staff consult on New Zealand and international standards for the chemical preservation of timber and for timber used in building.
We offer testing services for timber treatment plants, timber compliance consultants and building suppliers including accelerated testing procedures for above ground preservative systems.We also develop new testing protocols for New Zealand and Australian industry standards.
Read about Scion’s graveyard where wood and other materials are exposed to the elements long-term.
A commercial timber preservative testing service is provided by Scion's Veritec laboratory.
Specialty wood products
New manufacturing options for eucalypts, Douglas-fir, cypresses, other exotic and indigenous species are being investigated.
The Specialty Wood Products Partnership (SWPP) is a seven year partnership supported by the Ministry for Business Innovation and Employment (MBIE) and the forestry industry via the Forest Grower Levy Trust.
Read about how government and industry plan to work together to tackle the challenges of geographic spread, small scale and processing to transform the timber from variety of species into high value products.
Processing options for non-durable eucalypts, Douglas-fir, and cypresses
Shrinkage and internal checking can be reduced in hard-to-dry species using a supercritical carbon dioxide pre-treatment before kiln drying. This technology can also be applied to indigenous species including tōtara and beech.
Tōtara, kauri and other species have the potential to provide multiple benefits to New Zealand. As part of supporting industry based around indigenous trees we are developing a better understanding of tōtara wood density and durability and comparing the properties of kauri from different provenances.