OSB boards are boards made up of wood chips oriented in 3 layers interspersed and glued with polyurethane and MUPF resins (Melamina Urea Fenol Formol). The preparation of the chips separately for the different layers of the board and its special geometry (with lengths up to 150 mm), as well as a perfect orientation of such chips in the layers of the board, provide exceptional technical characteristics and a pleasant aesthetic look.
This type of boards is an evolution of the plywood boards, where instead of joining several sheets or sheets of wood, what is joined are several layers formed by chips or wood chips, oriented in the same direction. As in the counterchap, each layer follows a perpendicular orientation to the previous layer, so that a material with a more homogeneous behavior is obtained against dilations or efforts in different directions.
The chips usually have sizes from 80 mm to 150 mm, and are combined with various agglomerants, using pressure and high temperatures.
The most used agglomerants are phenolic resins, polyurethane resins, and different adhesives based on urea, formol or melamine.
It is also possible to incorporate additives to improve the board's performance, whether to increase fire resistance, humidity, or insect attack.
The boards have thicknesses between 6 and 28 mm, and dimensions around 2 meters. Its density is variable, but generally similar to that of light woods, around 650 kg/m3. Its insulation, soundproofing and resistance properties are similar to those of "natural" wood, although the addition of resins and additives usually confer slightly improved characteristics. In addition, thanks to the manufacturing process, flaws are eliminated in the form of knots, slices, veins or holes that can present untreated wood, so for normative purposes, the OSB boards (as well as all wood products) obtain better results.
According to the treatments and additives to which they are subjected, the guided chip boards are classified into 4 groups:
* OSB/1 for interior
* OSB/2 for dry environment
* OSB/3 for structure in wet environment
* OSB/4 high-performance structure
