Panel other wood-based materials

Wood-based panels sueh as partieleboard, MDF and OSB eaeh represent a solution to a particular market demand, often for a produet that ean be handled like wood but without the limitations of that material. The ability to make panels in a range of sizes and thicknesses, with uniform, predietable properties tailored to partieular applieations has been a major faetor in the signifieant growth of these materials. Eaeh of these panel types uses a raw material that is either a waste stream from other wood processing operations, or is wood that is unsuitable for other uses. There is thus a ready source of raw material. In addition the proeesses have demonstrated an ability to use a range of raw materials, both in form, and in different wood speeies, extending this use to inelude reeyeled wood from urban waste streams and to agricultural residues. 

Phenol-formaldehyde resins are among the most important polymeric adhesives used in the wood based composite panel manufacturing industries [1]. Phenolic resins are prepared by the reaction of phenol or any substituted phenol with formaldehyde or other aldehydes, in the presence of acidic or basic catalyst. The price of phenol depends on the oil price and is likely to ever increase due to shortage of fossil resources. Hence, several lignin substitute products based on renewable materials derived from annual plants such as flax [2, 3] or kenaf [4], agricultural waste such as sugar cane bagasse [5] and wheat straw [6] or by-products from the... 

There are two basic categories of acceptance standards performance standards and product specifications. Performance standards focus on the ability of a material, component or assembly to resist the loads or environmental effects of its intended application. Product specifications focus on aspects of material quality, which may affect strength, appearance and durability. In some instances it may be possible to use existing standards directly with newly developed products and materials in other cases it may be necessary to modify existing standards or develop new standards to assure equitable evaluation. Consensus committees comprising producer, consumer, and user groups develop performance standards, which are used to evaluate the engineering performance of wood-based panels, such as hardboard, MDF and particleboard. This standard was used because no standard exists for the evaluation of woodfibre-plastic panel materials. 

Even with only the three monomers melamine, formaldehyde, and urea, a variety of different types of resins exists which can fulfill nearly all requirements given in the wood-based panels industry. This field of application involves the production of wood-based panels like particleboards, medium density fiberboard (MDF), oriented strand board (OSB), plywood, blockboards, and others. In rare cases the resins and panels are also used in the fnrnitnre industry. According to the raw materials used, various types of melamine resins are possible ... 

An area that has seen a lot of interest is in the use of waste rubber to produce sound insulation materials. Zhao and co-workers [68] have investigated the properties of waste tyre rubber/wood composites for sound insulation applications. They used a four-microphone method to measure and compare the sound transmission losses of three different composite panels the waste tyre/wood material, a commercial wooden floorboard, and a commercial wood-based particle board. The waste tyre rubber/wood product was manufactured in the laboratory with commercial urea-formaldehyde and a PU adhesive. The results obtained indicated that the sound insulation properties of the waste rubber/wood material were better than the other two products. Also, its insulation properties were significantly affected by the amount of rubber crumb and the amount of PU adhesive used, the performance improving as the quantity of both ingredients was increased. In the case of the PU adhesive, this was due to the formation of more complete rubber-adhesive interfaces within the material. 

In the construction industries, UPE-based FRP has been replacing aluminium, stainless steel and wood because of its low cost, and ease of cleaning and working. The examples for such applications are solar panels, wall liners, automobile components, liners for truck trailers and railroad cars. UPE-FRP products are used to make sanitary ware as replacements for conventional materials such as porcelainised cast iron due to their obvious advantages of lower cost and easier installation. The other related applications are bath tubs, showers, toilets and sinks. 

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