Musical Acoustics Lab at the Violin Museum of Cremona, DEIB-Politecnico di Milano, Cremona Campus, Cremona, Italy.
Arvedi Laboratory of non-Invasive Diagnostics, CISRiC, University of Pavia, Via Bell'Aspa 3, 26100, Cremona, Italy.
Sci Rep. 2022 Aug 3;12(1):13335. doi: 10.1038/s41598-022-17596-z.
It is commonly believed that violins sound differently when finished. However, if the role of varnishes on the vibrational properties of these musical instruments is well-established, how the first components of the complete wood finish impact on the final result is still unclear. According to tradition, the priming process consists of two distinct stages, called pre-treatment and sizing. The literature reports some recipes used by old Cremonese luthiers as primers, mainly based on alkaline aqueous solutions and protein-based glues. In this manuscript, we analyze the impact of these treatments on the mechanical properties of the material. The combination of two pre-treatments and three sizes is considered on nine different plates. We compare the vibrational properties before and after the application and assess the effects of the different primers, also supported by finite element modeling. The main outcome is that the combination of particular treatments on the violin surface before varnishing leads to changes not only to the wood appearance, but also to its vibrational properties. Indeed pre-treatments, often considered negligible in terms of vibrational changes, enhance the penetration of the size into the wood structure and strengthen the impact of the latter on the final rigidity of the material along the longitudinal and radial directions.
人们普遍认为，小提琴在完成后会发出不同的声音。然而，如果说清漆对这些乐器的振动特性的影响已经得到很好的证实，那么木材初始涂层对最终结果的影响仍不清楚。根据传统，底漆工艺由两个不同的阶段组成，称为预处理和上浆。文献中报道了一些旧的克雷莫纳制琴师使用的底漆配方，主要基于碱性水溶液和蛋白质基胶水。在本文中，我们分析了这些处理方法对材料机械性能的影响。在九块不同的板上考虑了两种预处理和三种上浆的组合。我们比较了应用前后的振动特性，并通过有限元建模评估了不同底漆的影响。主要结果是，在涂清漆之前，小提琴表面的特定处理组合不仅会改变木材的外观，还会改变其振动特性。事实上，预处理通常被认为对振动变化影响不大，但它可以增强上浆对木材结构的渗透，并增强后者对材料纵向和径向最终刚性的影响。
