The principle of dry wood
On the premise of guarantee the quality of dry improve the drying speed is the basic principles of dry wood. Drying quality requirement is that they have been dried wood end moisture content and drying uniformity can satisfy the requirement of processing technology; Maintain the integrity of the wood, not occur for process specification does not allow defects, don’t change due to the nature of the wood. Drying rate per unit of time the degree of lumber moisture content is lower. The faster the drying (or the shorter the drying cycle), need drying equipment and investment is less, the lower the cost of drying. All kinds of wood products for the dried wood moisture content requirements in different usage varies, such as instrument, precision instruments cases (7%); Furniture, parquet floor is 8%; Joinery board for 8 ~ 9%; Sports equipment is 10 ~ 12%; Window and door is 12%; Automobile, railway passenger cars is 10 ~ 15%; Railway wagon, building materials is 18%; packing box is 15 ~ 18%. In practice, it is necessary to make appropriate changes in the climate conditions of the products used in the region.
In wood drying process, must change at different drying stages corresponding dry indoor relative humidity, on the basis of the development of relative humidity change procedures or drying. Different tree species, different thickness of the timber has different drying standards, generally fall into two categories, drying time and moisture content of drying. The former stage operation according to time and the latter by the water-cut stage operation, belong to the water-cut stage operation and fluctuation and half wave drying benchmark. Dry benchmark whether the selection of appropriate, has a direct effect on the yield and quality of wood drying.