文献类型：期刊文献

英文题名：Water uptake of radiata pine wood after microwave and superheated steam treatments: sapwood vs. heartwood

作者：Cao, Huimin[1,2] Huang, Saisai[1] Yin, Fangyu[1] Gao, Yufa[1] Liao, Xiaomei[1] Yi, Songlin[2] Zhou, Yongdong[1]

第一作者：Cao, Huimin

通信作者：Zhou, YD[1]

机构：[1]Chinese Acad Forestry, Res Inst Wood Ind, Beijing 100091, Peoples R China;[2]Beijing Forestry Univ, Coll Mat Sci & Technol, Beijing 100083, Peoples R China

年份：2023

外文期刊名：EUROPEAN JOURNAL OF WOOD AND WOOD PRODUCTS

收录：;EI(收录号：20235115234315);Scopus(收录号：2-s2.0-85179703688);WOS:【SCI-EXPANDED(收录号:WOS:001129151400001)】；

基金：The authors would like to acknowledge Fundamental Research Funds of CAF (No. CAFYBB2021QA003) and the Nature Science Foundation of China (No. 31890772) for funding. The authors also thank Han Cui from shiyanjia lab for support of automatic mercury porosimeter test (www.Shiyanjia.com).

语种：英文

外文关键词：Canals - Dyeing - Electric discharges - Hydraulic structures - Water treatment - Wood products

摘要：Resin canals and ray cells in pine wood connect the interior to the exterior. The blockage of resin canals and ray cells by the resin, directly determines the water uptake of the wood. However, research on water uptake by resinous wood is lacking. Hence, this study aimed to explain how microwave (MW) or superheated steam (SS) treatment improves wood water uptake from the perspective of resin content (RC). Therefore, radiata pine sapwood and heartwood were treated with MW, SS, or microwave-superheated steam (MS) for different times. The results showed that MW and SS treatments expelled the internal resin of radiata pine. Owing to the low RC and high moisture content (MC) of sapwood, the effect of the MW treatment on the RC of radiata sapwood was insignificant. Heartwood has a markedly higher RC and lower MC than sapwood; therefore, MW treatment can drive part of the resin to migrate out of the wood. With increasing SS treatment time, the RC of the sapwood and heartwood decreased to varying degrees; however, the core layer resin could not be completely removed. In addition, MW treatment can accelerate the degreasing process as it discharges some part of the resin and opens some parts of the resin canals. Moreover, MS treatment can increase the porosity of sapwood and heartwood due to the expulsion of resin. MS treatment had no significant effect on sapwood water uptake; however, it increased that of heartwood by more than three times. The dye solution enters the wood through the open resin canals or ray cells and communicates with the axial resin canals. Therefore, the water uptake of heartwood is mainly related to the resin content and the blockage of the resin canals by the resin determines the entry of the dye solution to the interior of the wood.