Kain Günther, Tudor Eugenia Mariana, Barbu Marius-Catalin
Forest Products Technology and Timber Construction Department, Salzburg University of Applied Sciences, Markt 136a, 5431 Kuchl, Austria.
Higher Technical College Hallstatt, Lahnstraße 69, 4830 Hallstatt, Austria.
Polymers (Basel). 2020 Sep 19;12(9):2140. doi: 10.3390/polym12092140.
Tree bark is a byproduct of the timber industry which accrues in large amounts, because approximately 10% of the volume a log is bark. Bark is used primarily for low-value applications such as fuel or as a soil covering material in agriculture. Within the present study, thermal insulation panels made from larch, pine, spruce, fir and oak tree bark with different resins (urea formaldehyde, melamine formaldehyde, Quebracho, Mimosa) as a binder are discussed. Also, the properties of panels made from larch bark mixed with industrial popcorn are investigated. The physical-mechanical properties of the panels, which are dependent on panel density, bark species, resin type, resin content and particle size, are analyzed. The bark species has a minor effect on the mechanical characteristics of the panels, while the compression ratio is important for the panel strength, and hence, barks with lower bulk density are preferable. Under laboratory conditions, panels made with green tannin resins proved to have adequate properties for practical use. The addition of popcorn is a means to lower the panel density, but the water absorption of such panels is comparably high. The bark type has a minor effect on the thermal conductivity of the panels; rather, this parameter is predominantly affected by the panel density.
树皮是木材工业的一种副产品，其产量很大，因为一根原木大约10% 的体积是树皮。树皮主要用于低价值用途，如燃料或作为农业中的土壤覆盖材料。在本研究中，讨论了以落叶松、松树、云杉、冷杉和橡树树皮为原料，用不同树脂（脲醛、三聚氰胺甲醛、坚木、含羞草）作为粘合剂制成的保温板。此外，还研究了由落叶松树皮与工业爆米花混合制成的板材的性能。分析了板材的物理力学性能，这些性能取决于板材密度、树皮种类、树脂类型、树脂含量和颗粒大小。树皮种类对板材的机械特性影响较小，而压缩比对于板材强度很重要，因此，堆积密度较低的树皮更可取。在实验室条件下，用绿色单宁树脂制成的板材被证明具有足够的实际使用性能。添加爆米花是降低板材密度的一种方法，但这类板材的吸水率相对较高。树皮类型对板材的热导率影响较小；相反，这个参数主要受板材密度的影响。
