Robinia pseudoacacia sawn timber drying method

Abstract

The invention discloses a robinia pseudoacacia sawn timber drying method, relating to the technical field of wood processing. The robinia pseudoacacia sawn timber is stacked before being dried. The drying method comprises the following steps: a. in a pre-heating treatment stage, the dry ball temperature is controlled to be 55-65 DEG C, the dry-wet ball temperature difference is controlled to be 1-2 DEG C and the treatment time is controlled to be 3-8 hours; b, in a drying stage, the moisture content is controlled to be over 30%, the dry ball temperature is 50-60 DEG C, and the dry-wet ball temperature difference is 2-3 DEG C; a humidity-regulating treatment stage is implemented when the moisture content reaches 8-12% after drying in a staging manner, wherein the dry ball temperature is controlled to be 75-85 DEG C, the dry-wet ball temperature difference is controlled to be 3-5 DEG C, and the treatment time is controlled to be 6-12 hours; d, in a cooling stage, the sawn timber is cooled within a temperature which is higher than an outdoor temperature by 20 DEG C, and the dry-wet ball temperature difference is kept within 6-10 DEG C. According to the drying method, the dried robinia pseudoacacia sawn timber which is uniform in moisture distribution, small in residual drying stress, cannot easily deform and crack in later process and use is obtained.

Description

technical field [0001] The invention relates to the technical field of wood processing, in particular to a drying method for sawn timber of locust locust. Background technique [0002] Black locust has the advantages of fast growth, strong adaptability, and salt-alkali tolerance. It is one of the important fast-growing tree species in my country. It is a common tree species for water and soil conservation, windbreak and sand fixation, soil improvement and surrounding greening in North and Northwest China. It is mainly distributed in Hebei and Henan. , Shandong, Shanxi, Shaanxi and other provinces and cities, the planting area of ​​black locust in my country is about 10 million hm 2 above. Robinia pseudoacacia has a high air-dry density, hard wood, beautiful texture, and good wear resistance. The heartwood has good durability, moisture resistance, and corrosion resistance; The pass rate is low, only about 75-80%. The low yield and poor benefit of Robinia pseudoacacia during...

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Problems solved by technology

[0003] The existing domestic forestry industry standard LY / T1068-2012 "Sawwood Kiln Drying Process Regulations" contains relevant content on the drying process of Robinia locust, but the process in this regulation is to use the original natural forest wood, and the drying conditions are more severe, which will cause As a result, the sawn timber of Robinia pseudoacacia has serious defects such as cracking and deformation during the drying process, and the qualified rate is low, so enterprises dare not use it; most of the processes currently used in enterprises are drying processes in the range of 40-60 degrees, and the drying time is long. In the early stage of drying at low temperature and high humidity, it is very easy to cause mildew on the sawn timber and reduce the material quality, and the residual drying stress of the sawn timber after drying by the enterprise process is large, which will easily cause defects such as cracking and deformation of the material or products during reprocessing, and reduce the quality of the material. The yield rate and product qualification rate seriously affect the benefits and production efficiency of enterprises, so that the use of locust wood in furniture, flooring and other wood products is still an uncommon wood type

The research on the drying of black locust wood mainly focused on the drying research on black locust logs in the 1990s, such as Gao Jianmin’s “Study on the drying characteristics of black locust logs” [Forest Industry, 1994, 21(2): 5-7] , "A Preliminary Study on the Drying Process of Small-diameter Logs" [Wood Industry, 1994, 8(1): 26-29], Zhang Yunling and Zhou Chuandong's "Little-diameter Wood Drying Benchmark" [Henan Science and Technology, 1996, (10): 11], Zhang Yunling " Robinia locust wooden mosaic production technology”; and the drying of black locust cross-section thin slices, such as Wang Liyu’s “Microwave drying technology of Robinia locust small-diameter wood round and oblique slices” [Journal of Beijing Forestry University, 1998, 20(5): 103-107], domestic There is a report on the drying characteristics of Robinia pseudoacacia using the Baidu method [Zhang Zhenzhen, Huang Saibei, Song Shifeng, etc. Drying characteristics of Robinia pseudoacacia small-diameter timber, China Timber, 2011, (6): 28-30], but the research on the drying of Robinia pseudoacacia sawn timber and There is no report on the application. This technology aims to provide technical support for the large-scale application of black locust wood and the manufacture of high value-added solid wood products of black locust

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