OSB (Oriented Strand Board) is a type of panel for construction, obtained by gluing and compressing irregular wood chips.Invented in 1963, it is widely used today to make the construction of buildings and homes cheaper, easier and more flexible.OSB is the acronym for Oriented Strand Board, which can be translated into Italian as a panel of oriented flakes.OSBs are also known as flakeboard (slat board), sterling board or aspenite.It is a type of composite wood similar to chipboard, formed by adding adhesives and then compressing layers of wood chips oriented in specific directions.It was invented in 1963 in California by Armin Elmendorf.The OSB panels have a characteristic rough and variegated surface in which the individual wood chips superimposed and glued to each other are clearly visible, from the standard size of about 2.5 cm x 15 cm.They are available in various sizes, types and thicknesses.Oriented Strand Boards have excellent mechanical properties;this makes them particularly suitable for construction applications to withstand even quite high loads.Today they have become more popular than plywood panels, accounting for 66% of the structural panel market.The most common uses concern siding, which is the outermost protective layer of walls, floors and roofs.For application on external walls, the panels are available with a pre-laminated layer that reflects thermal radiation and reduces heat transfer;this makes installation easier and more immediate and increases the energy efficiency of the building envelope, making it possible to use these panels also in green building.Some types of OSB are also used in the production of low-cost furniture.Small variations in the manufacturing process of a panel can also considerably change its thickness, size, strength and stiffness.Oriented Strand Boards have no cavities or voids inside, and can be waterproofed through additional external layers.The final product has similar properties to plywood, but is more uniform and cheaper.Breaking tests have shown that OSBs can withstand higher loads than chipboard and plywood panels.This is why, especially in North America, they have supplanted the other types of structural panels.OSBs do not have a continuous grain like natural wood;they have an axis along which they have greater strength and stiffness.This stronger direction can be deduced from the direction of the surface wood chips.They share the ease of cutting, manufacturing and installation with other types of wood panels.Oriented Strain Boards are produced as large tangles of various layers of thin rectangular wooden strips crossed, compressed and glued with wax and synthetic adhesive resins.Usually a panel of this type is made up of 95% wood chips and 5% wax and resin.Different types of adhesive resins can be used: urea-formaldehyde for OSB type 1, non-structural and non-waterproof, mainly used for the production of furniture or interior coverings;glues based on isocyanates or diphenylmethno-diisocyanate inside with melamine-urea-formaldehyde or phenolic-type resins on the surface for OSB type 2 panels for exteriors, structural and water-resistant on the surface;Phenolic resins throughout the panel for OSB type 3 and 4, structural and totally waterproof, usable in very humid outdoor environments.The layers are created by cutting the wood into strips which are sieved and then oriented on strips or wire.The tangle is produced on an assembly line.The wooden strips of the outer layers are aligned with the resistant axis of the panel, while those of the inner layers are perpendicular.The number of layers is determined in part by the thickness of the panel but is also limited by the capacity of the manufacturing plant's machinery.The thickness of the individual layers can also vary to give a different thickness to the finished panel;usually 10 layers form a panel, so from 15 mm layers you get a 15 cm thick panel.The tangle is then placed in a thermal press to compress the flakes and unite them through the thermal activation of the resin with which the strips have been coated.Finally the tangle is cut into individual panels of the desired size.The largest producer of OSB is Canada, which in 2005 produced over 10 million square meters of panels;Canada exports most of the panels produced in the USA.In Europe, the largest producer is Romania, which exports many panels to Ukraine and Russia.The reckless use of Oriented Strand Boards in very humid environments in Canada has led to the leaky condo crisis (literally the crisis of condominiums leaking water): insufficient waterproofing has led to water infiltration in many Canadian buildings;the cost of rebuilding these buildings is estimated to be $ 4 billion.The resins used in the production of OSB emit toxic volatile organic compounds such as formaldehyde.Urea-formaldehyde is toxic and cannot be used inside buildings.Phenolic resins are much less dangerous from this point of view.The latest generation OSBs use isocyanate resins that do not contain formaldehyde and are not volatile after thermal compression.Some manufacturers treat wood chips with borates that are toxic for termites and other wood-attacking insects, mold and fungus, but not for mammals.Your email address will not be published.Required fields are marked *This site uses Akismet to reduce spam.Find out how your data is processed.Always stay updated with us!By subscribing to the newsletter you consent to the processing of personal data pursuant to law n.196/2003.For more information, click hereOver 2000 users have already subscribed to our newsletter.Always stay updated with us.By subscribing to the newsletter you consent to the processing of personal data and I accept the Privacy Policy.Copyright © 2022, different, All rights reserved.