OSB

OSB may refer to:

Christianity

Osmium borides

Osmium borides are compounds of osmium and boron. Their most remarkable property is potentially high hardness. It is thought that a combination of high electron density of osmium with the strength of boron-osmium covalent bonds will make osmium borides superhard materials. This has not been demonstrated yet. For example, OsB₂ is hard (hardness comparable to that of sapphire), but not superhard.

Synthesis

Osmium borides are produced in vacuum or inert atmosphere to prevent formation of osmium tetroxide, which is a hazardous compound. Synthesis occurs at high temperatures (~1000 °C) from a mixture of MgB₂ and OsCl₃.

Structure

Three osmium borides are known: OsB, Os₂B₃ and OsB₂. The first two have hexagonal structure, similar to that of rhenium diboride. Osmium diboride was first also sought as hexagonal, but its structure was later reassigned to orthorhombic.

References

Oriented strand board

Oriented strand board (OSB), also known as sterling board, sterling OSB, aspenite, and smartply in British English, is an engineered wood particle board formed by adding adhesives and then compressing layers of wood strands (flakes) in specific orientations. It was invented by Armin Elmendorf, California US in 1963 OSB Patent. OSB may have a rough and variegated surface with the individual strips of around 2.5 × 15 cm (1" × 6"), lying unevenly across each other and comes in a variety of types and thicknesses.

Uses

OSB is a material with high mechanical properties that make it particularly suitable for load-bearing applications in construction. The most common uses are as sheathing in walls, flooring, and roof decking. For exterior wall applications, panels are available with a radiant-barrier layer pre-laminated to one side; this eases installation and increases energy performance of the building envelope. OSB also sees some use in furniture production.

Manufacturing

Oriented strand board is manufactured in wide mats from cross-oriented layers of thin, rectangular wooden strips compressed and bonded together with wax and synthetic resin adhesives (95% wood, 5% wax and resin). The resin types typically used include Phenol formaldehyde (PF), melamine fortified Urea Formaldehyde (MUF) or isocyanate (PMDI), all of which are moisture resistant binders. In Europe, it is common to use a combination of binders, typically PMDI would be used in the core and MUF in the face layers and this has the advantage of reducing press cycles whilst imparting a bright appearance to the surface of the panel.