High-temperature lumber convective treatment method for balancing lumber moisture content

Abstract

The invention relates to a high-temperature wood convective treatment method for balancing lumber moisture content. The adopted technical scheme includes that lumber pieces are bonded and stored for over 72 hours in natural conditions; the naturally dried lumber pieces are piled in layers in a steam lumber drying furnace, stripped cushions are put in parallel on each layer of lumber, the lumber pieces are erected in the middle space of the furnace, the lumber volume takes up 60 percent of the cubage of the steam lumber drying furnace; the furnace is heated and the temperature is kept under 50-55 degrees Celsius to dry the lumber for 48 hours and moisture is discharged once every four hours; the furnace temperature is kept under 60-65 degrees Celsius for 36 hours to dry the lumber and moisture is discharged once every six hours; the furnace temperature is kept under 70-80 degrees Celsius for 24 hours to dry the lumber and moisture is discharged once every eight hours; the steam lumber drying furnace is stopped for 3-5 hours after drying for 10-14 hours; the furnace is cooled down and the temperature of the lumber being taken out of the furnace is controlled. The invention guarantees the moisture content difference between every two lumber pieces within 1 percent and prevents lumber from shrinkage, cave-in, warp, distortion and cracking in a long period; the woodwork produced by the invention has stable quality and long service life.

Description

technical field [0001] The invention relates to the field of wood drying methods, in particular to a method for treating wood with high-temperature gas convection to balance the moisture content of wood. Background technique [0002] With the continuous improvement of wood drying technology, artificial steam drying technology has been widely used. But its shortcoming is that the wood products made of gluing, after a long time of use, are prone to quality problems such as collapse, warping, deformation, cracking, etc., which affect the appearance and performance of the product. The main reasons are: first, the existing artificial steam The moisture content of wood processed by wood drying technology is generally different; the moisture content of wood in the middle part of the drying kiln is 5-10% higher than that of the wood at the top of the drying kiln, and about 10% lower than that at the bottom of the drying kiln. The highest difference is about 20%. Once it is glued an...

AI Technical Summary

Problems solved by technology

But its shortcoming is that the wood products made of gluing, after a long time of use, are prone to quality problems such as collapse, warping, deformation, cracking, etc., which affect the appearance and performance of the product. The main reasons are: first, the existing artificial steam The moisture content of wood processed by wood drying technology is generally different; the moisture content of wood in the middle part of the drying kiln is 5-10% higher than that of the wood at the top of the drying kiln, and about 10% lower than that at the bottom of the drying kiln. The highest difference is about 20%. Once it is glued and used for a long time, when the indoor air humidity is lower than the moisture content value of the wood, the moisture contained in the wood will evaporate, which will cause the wood to shrink and then collapse; Water-based adhesives are generally used for gluing. After gluing, the wood itself absorbs water and dries naturally at room temperature outside the body. Due to the short drying time of wood gluing, it is impossible to avoid the residual moisture in the wood, which will cause the wood fibers to expand and collapse after drying. The third is The difference between the moisture absorption and dry shrinkage coefficients of the warp and string-cut boards of wood is about 3 times each other. Natural growth, due to the different geographical environment of growth, the morning and evening wood and wood fiber density of trees grow differently, and the moisture content and moisture absorption are different in the process of steam drying and gluing. After a long time, the wood shrinks and collapses. warping, deformation