Oriented structural straw board

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Oriented structural straw board (OSSB) is an engineered board that is made by splitting straw and formed by adding formaldehyde-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, Canada (today AITF)[1] which identified the straw strand manufacturing technology using formaldehyde-free (p-MDI) adhesives.

Uses[edit]

OSSB can replace wood oriented strand board (OSB) and particle board in structural and non-structural applications, such as interior and exterior walls for house construction, furniture and interior decoration.[2] [3] 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[edit]

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.[4] 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.

Production[edit]

One producer of OSSB on a commercial scale is Novofibre Panel Board Holding China, Ltd., located in Yangling, Shaanxi province in China. Currently, their factory has a 60,000-cubic-metre (2,120,000 cu ft; 78,500 cu yd) yearly capacity.

Properties[edit]

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.[5] The resin used to manufacture OSSB is p-MDI, which does not emit volatile organic compounds (VOCs) and is formaldehyde-free.[6] The raw material can be treated by various borate compounds, which are toxic to termites, beetles, molds, and fungi, but not to mammals in applied doses.[7]

Types[edit]

OSSB boards are available in thicknesses varying from 3–30 mm (0.12–1.18 inches) in different densities. Novofibre Panel Board Holding China, Ltd., manufactures 3 standard products:

  1. OSSB1 - General purpose boards for construction and interior decoration.
  2. OSSB 3 - Load-bearing boards for use in construction with high strength stability needs.
  3. OSSB DECO–multipurpose boards with a unique elegant texture, which is especially suitable for decoration.
  4. OSSB panels can be produced in a range of finished products for acoustic, floor or home applications keeping the natural straw surface appearance.

See also[edit]

References[edit]

  1. ^ "Oriented split Straw Board - A New Era in Building Products". Builddwelllibrary.org. Retrieved 2015-10-25.
  2. ^ "Performance of Zinc Borate-Treated Oriented Structural Straw Board against Mold Fungi, Decay Fungi, and Termites - A Preliminary Trial" (PDF). Ncsu.edu. Retrieved 2015-10-25.
  3. ^ "Utilization of Wheat Straw as a Building Material——Oriented Structural Straw Board in a Housing System-《China Wood Industry》2010年03期". En.cnki.com.cn. Retrieved 2015-10-25.
  4. ^ Wasylciw, Wayne (2001). "Oriented Split Straw Board – A New Era In Building Products". American Society of Agricultural and Biological Engineers Annual Meeting. doi:10.13031/2013.4213. Retrieved 19 September 2017.
  5. ^ "ARC Celebrates OSSB "Wheatboard" in China". Albertatechfutures.ca. 2009-10-29. Retrieved 2015-10-25.
  6. ^ "MDI – a simple equation for OSB production? - Wood Based Panels". Wbpionline.com. Retrieved 2015-10-25.
  7. ^ "Performance Of Zinc Borate-Treated Oriented Structural Straw Board Against Mold Fungi, Decay Fungi, And Termites – A Preliminary Trial | Han | Bioresources". Ojs.cnr.ncsu.edu. Retrieved 2015-10-25.