Mamoňová Miroslava, Ciglian Dávid, Reinprecht Ladislav
Department of Wood Science, Faculty of Wood Sciences and Technology, Technical University in Zvolen, T. G. Masaryka 24, 960 01 Zvolen, Slovakia.
Department of Wood Technology, Faculty of Wood Sciences and Technology, Technical University in Zvolen, T. G. Masaryka 24, 960 01 Zvolen, Slovakia.
Materials (Basel). 2022 Sep 16;15(18):6440. doi: 10.3390/ma15186440.
This study deals with the scanning electron microscopy (SEM) analyses of the phase interfaces in the glued joints between Norway spruce wood elements thermally modified at 160, 180, 200, and 220 °C/4 h and polyurethane (PUR) and polyvinyl acetate (PVAc) glues with the aim of evaluating various anatomical influences of wood on the quality of joints. Due to cracked regions created in the surface of spruce wood at severe thermal modifications, the penetration depth of glues doubled from 140 to 241 μm for PUR glue, and from 100 to 200 μm for PVAc glue. The thickness of glue lines in joints was apparently higher for PVAc glue, mainly in earlywood regions; however, in joints from thermally modified (TM) woods it increased more apparently for PUR glue from 16.6 to 44.4 μm, probably in connection with formation of micro-bubbles in its structure. The SEM analyses corresponded well with the previous knowledge about lower shear strength of glued joints formed from the more intensively TM spruce elements and mentioned types of glues.
本研究对在160、180、200和220°C/4小时进行热改性的挪威云杉木构件与聚氨酯（PUR）和聚醋酸乙烯酯（PVAc）胶水之间的胶合接头中的相界面进行了扫描电子显微镜（SEM）分析，目的是评估木材的各种解剖结构对接头质量的影响。由于在严重热改性的云杉木表面形成了裂纹区域，PUR胶水的渗透深度从140μm增加到241μm，PVAc胶水的渗透深度从100μm增加到200μm，增加了一倍。PVAc胶水在接头中胶层的厚度明显更高，主要在早材区域；然而，在热改性（TM）木材制成的接头中，PUR胶水的胶层厚度从16.6μm增加到44.4μm更为明显，这可能与其结构中形成微气泡有关。SEM分析与先前关于由改性程度更高的TM云杉木构件和上述类型胶水形成的胶合接头抗剪强度较低的认识非常吻合。
