Réh Roman, Igaz Rastislav, Krišťák Ľuboš, Ružiak Ivan, Gajtanska Milada, Božíková Monika, Kučerka Martin
Faculty of Wood Sciences and Technology, Technical University in Zvolen, 96001 Zvolen, Slovakia.
Faculty of Engineering, Slovak University of Agriculture in Nitra, 94976 Nitra, Slovakia.
Materials (Basel). 2019 Apr 20;12(8):1298. doi: 10.3390/ma12081298.
The results of research into utilizing grinded beech bark in order to substitute commonly used fillers in urea formaldehyde (UF) adhesive mixtures to bond plywood are presented in the present study. Four test groups of plywood with various adhesive mixtures were manufactured under laboratory conditions and used for experimentation. Plywood made using the same technology, with the common filler (technical flour), was used as a reference material. Three different concentrations of grinded beech bark were used. The thermal conductivity of the fillers used, viscosity and its time dependence, homogeneity and the dispersion performance of fillers were evaluated in the analysis of adhesive mixture. The time necessary for heating up the material during the pressing process was a further tested parameter. The produced plywood was analyzed in terms of its modulus of elasticity, bending strength, perpendicular tensile strength and free formaldehyde emissions. Following the research results, beech bark can be characterized as an ecologically friendly alternative to technical flour, shortening the time of pressing by up to 27%. At the same time, in terms of the statistics, the mechanical properties and stability of the material changed insignificantly, and the formaldehyde emissions reduced significantly, by up to 74%. The utilization of bark was in compliance with long-term sustainability, resulting in a decrease in the environmental impact of waste generated during the wood processing.
本研究展示了利用磨碎的山毛榉树皮替代脲醛（UF）胶粘剂混合物中常用填料以粘结胶合板的研究结果。在实验室条件下制造了四组使用不同胶粘剂混合物的胶合板并用于实验。使用相同工艺、添加普通填料（工业面粉）制成的胶合板用作参考材料。使用了三种不同浓度的磨碎山毛榉树皮。在胶粘剂混合物分析中评估了所用填料的热导率、粘度及其时间依赖性、填料的均匀性和分散性能。压制过程中材料升温所需时间是另一个测试参数。对生产出的胶合板进行了弹性模量、抗弯强度、垂直抗拉强度和游离甲醛释放量分析。根据研究结果，山毛榉树皮可被视为工业面粉的生态友好替代品，可将压制时间缩短多达27%。同时，从统计数据来看，材料的机械性能和稳定性变化不显著，而甲醛释放量显著降低，多达74%。树皮的利用符合长期可持续性，减少了木材加工过程中产生的废物对环境的影响。
