Constança Carvalho, Daniel Alves, Andrew Knight and Luis Vicente
Eduardo Luiz Longui, Iris Brémaud, Francides Gomes da Silva Júnior, Daniel Romeu Lombardi and Edenise Segala Alves
In this paper we investigate the influence of extractives, lignin and holocellulose contents on performance index (PI) of seven woods used or tested for violin bows. Woods with higher values of this index (PI = √MOE/ρ, where MOE is modulus of elasticity and ρ is density) have a higher bending stiffness at a given mass, which can be related to bow wood quality. Extractive content was negatively correlated with PI in Caesalpinia echinata, Handroanthus sp. and Astronium lecointei. In C. echinata holocellulose was positively correlated with PI. These results need to be further explored with more samples and by testing additional wood properties. Although the chemical constituents could provide an indication of quality, it is not possible to establish appropriate woods for bows solely by examining their chemical constituents.
Eduardo Luiz Longui, Takashi Yojo, Daniel Romeu Lombardi and Edenise Segala Alves
While the wood Caesalpinia echinata (pernambuco wood) is traditionally used in the manufacture of bows for string instruments, wood of other genera such as Handroanthus (syn. Tabebuia) and Manilkara are also used in bow making, but still on a very small scale. This study aims to evaluate the anatomical, chemical, physical, mechanical, and acoustic characteristics of these two latter woods, establishing their potential for bow making. Length, frequency of vessel elements and rays, and the higher percentage of fibers influence the density, modulus of elasticity, modulus of rupture, and the speed of sound propagation, whereas the content of lignin influence the sticks’ stiffness. It appears that Handroanthus bows can provide quality equivalent to that of pernambuco wood. Despite its appropriate heartwood color and texture, Manilkara provides bows of inferior quality.