Oriented structural straw board (OSSB) is an engineered board that is made by splitting straw and formed by adding

formaldehyde Formaldehyde ( , ) (systematic name methanal) is a naturally occurring organic compound with the formula and structure . The pure compound is a pungent, colourless gas that polymerises spontaneously into paraformaldehyde (refer to section ...

-free adhesives and then hot compressing layers of straw in specific orientations. Research and development for OSSB panels began in the mid 1980s and was spearheaded by the

Alberta Research Council Alberta Innovates (AI) is an Alberta government provincial corporation whose appointed Board of Directors is accountable to the Minister of Jobs, Economy and Innovation and is responsible for promoting innovation in the province. AI was created ...

, Canada (today AITF), which identified the straw strand manufacturing technology using formaldehyde-free (p-MDI) adhesives.

Uses

OSSB can replace wood

oriented strand board Oriented strand board (OSB) is a type of engineered wood similar to particle board, formed by adding adhesives and then compressing layers of wood strands (flakes) in specific orientations. It was invented by Armin Elmendorf in California in 1963 ...

(OSB) and

particle board Particle board, also known as chipboard or low-density fiberboard, is an engineered wood product manufactured from wood chips and a synthetic resin or other suitable binder, which is pressed and extruded. Particle board is often confused with ...

in structural and non-structural applications, such as interior and exterior walls for house construction, furniture and interior decoration. OSSB panels are formaldehyde-free, they are also used for applications where air quality is a concern, such as kindergartens, hospitals, bedrooms, and hotels.

Manufacturing

OSSB panel manufacturing starts with careful selection of straw fibres, which are then cut, cleaned, split and dried. Splitting straws allows resin to coat what would otherwise be the inside of a hollow straw. Producing split straw of sufficient length was the key technical innovation making OSSBs possible. OSSB is thus sometimes referred to as oriented split straw board. Formaldehyde free resin is added to the straw and the fibres are oriented for strength and appearance, and shaped into a mat through directional mat forming. The mat is then pressed between heated belts, water is vaporized, transferring heat into the straw. The heat cures the adhesive and causes a series of physical and chemical changes to the pressurized raw materials, which harden the final product.

Properties

OSSB panels have high structural strength, load bearing and stability in both directions, as well as superior workability and excellent nail holding properties on all sides. Water permeability treated OSSB panels are more water resistant than treated traditional wood panel boards because they have no internal gaps or voids. OSSB panels are also highly earthquake resistant. The resin used to manufacture OSSB is p-MDI, which does not emit

volatile organic compounds Volatile organic compounds (VOCs) are organic compounds that have a high vapour pressure at room temperature. High vapor pressure correlates with a low boiling point, which relates to the number of the sample's molecules in the surrounding air, a t ...

(VOCs) and is formaldehyde-free. The raw material can be treated by various

borate A borate is any of several boron oxyanions, negative ions consisting of boron and oxygen, such as orthoborate , metaborate , or tetraborate ; or any salt with such anions, such as sodium metaborate, and disodium tetraborate . The name also re ...

compounds, which are toxic to termites, beetles, molds, and fungi, but not to mammals in applied doses.

References

{{Reflist Composite materials

Uses

Manufacturing

Properties

See also

References