Remoistering of the wood before planing : a method for improved quality

It is beneficial if the machining of wooden products is done at a moisture content equal to the climate the product is meant to be used in. For indoor products in central heated houses such moisture content is about 5-10%. For planing this is often a too low moisture content showing an increased risk of poor surface quality due to severe torn grain. Contrary to this too high moisture content will result in a fuzzy grain surface and problems with swelling and shrinkage of the product. The roughness of a machined wooden surface is affected by a number of different parameters like cutting tool geometry, machine settings and wood structure. The latter is the hardest to control since the surface quality is a result of the local combination of density, grain direction and moisture content. The larger the variation in wood features the more difficult it is to find a combination of tools and machine settings that will give a high surface quality.This study showed that by wetting the surface before machining, in this case planing, the average surface quality could be increased. No time dependences could be shown, wetting short before planing did show as good improvements as wetting treatment for 30 minutes or more.The study was based on a total of 120 test surfaces of Scots pine (Pinus silvestris L.). In order to maximize the variation in grain angle and density variations the test surfaces contained both clear wood as well as green knots.<p>Godkänd; 2015; 20150625 (micohm)