Oriented strand board

There is a hybrid product available which has a veneer back, a layer of PF-coated wood particles, core veneer cross-ply, another layer of wood particles, and a top veneer. This assembly is pressed into a panel, trimmed to size, and sold into the stmctural-use panel market where it competes with plywood and oriented strand board. 

Economic Aspects. The stmctural plywood industry now has (ca 1997) about 105 operating mills, representing a significant decrease over the past several years. Production in 1994 was about 17.4 x 10 m (2), also representing a marked decrease over previous years. This decrease is a result of several factors, two of the most important being a decrease in availabiHty of suitable veneer logs, especially in the western states, and competition from the newer oriented strand board stmctural panel industries. 

Wood FIa.ke Boards. This category covers a range of products depending on the size and orientation of the wood flakes used. The earliest product was made in the 1950s using low density wood species, such as aspen and pine, with the flakes bonded together with phenoHc resins. Today there are two types of flake board, waferboard and oriented strand board (OSB). 

Several large applications for one-component moisture-cure urethane adhesives are available. Polymeric MDI is an exceptional binder for wood products, such as oriented strand board and particleboard. One-component urethane windshield adhesives are used almost exclusively in both the OEM and automotive aftermarket. One-part urethane adhesives are used to assemble the sidewalls for recreational vehicles (RV s), manufactured housing, and mobile homes. In construction applications, one-part urethanes are used to bond metal doors, hardwood flooring, panels, and partitions. 

In a study of acetylation of loblolly pine oriented strand board (OSB) flakes, it was found that reactivity of the wood increased in proportion to the juvenile wood content, when moving from the base to the top of the tree (Hon and Bangi, 1996). However, no difference in reactivity was found in moving from the core to the outer shell (i.e. radially). Rowell and Plackett (1988) found no difference in the reactivity of the heartwood and... 

The principle uses of the zinc borate Zn[B304(0H)3] are as a polymer additive and preservative for wood composites, such as oriented strand board (OSB). As a polymer additive it functions as a fire retardant synergist and modifier of electrical and optical properties. Its function as a fire retardant additive is discussed further below. A substantial amount of Zn[B304(0H)3] is used to improve the tracking index, which is an important performance criterion for polymers, such as polyamides (nylon) and polybutyl teraphtha-lates (PBT), used in electrical applications. 

Oriented strand board (OSB) is obtained from wood chips. The orientation is designed to simulate the characteristics of a wood panel, with limited swelling and higher resistance in the fibre direction. Chips are orientated by air with a blowing machine. These panels are commonly used on building sites, and they often make part of the walls in houses, especially in the United States. If no orientation is given, the panel is called waferboard. 

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