Effect of Moderate Thermal Treatment on Properties of Resonance Spruce for Piano Soundboard

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F62156489%3A43410%2F20%3A43918180" target="_blank" >RIV/62156489:43410/20:43918180 - isvavai.cz</a>

Výsledek na webu

<a href="http://www.swst.org/wp/wp-content/uploads/2020/07/SWST-2020-Proceedings-Final-final-final.pdf" target="_blank" >http://www.swst.org/wp/wp-content/uploads/2020/07/SWST-2020-Proceedings-Final-final-final.pdf</a>

DOI - Digital Object Identifier

—

Jazyk výsledku

angličtina

Název v původním jazyce

Effect of Moderate Thermal Treatment on Properties of Resonance Spruce for Piano Soundboard

Popis výsledku v původním jazyce

Thermal modifications of wood could provide perspective way to reduce negative effect of moisture on musical instruments. Resonance spruce (Picea abies L. Karst) used for soundboards is characterized by high sound velocity in longitudinal direction, low internal friction and high specific dynamic modulus of elasticity. The moderate thermal treatment with steam protection can maintain original acoustic properties with significant influence on equilibrium moisture content (EMC) and dimension stability. To test the effect of thermal treatment the 3 groups of specimens (44mm x 450mm x 12mm) of resonance wood selected from piano soundboards manufacturing have been prepared (un-treated, 180oC, 200oC) and conditioned in 20oC and relative humidity steps of 40%, 60% and 80%. The relative weight loss 4.7% and 7% was achieved by modifications at 180oC and 200oC respectively. EMC, longitudinal and bending dynamic modulus of elasticity, logaritmic decrement of damping and acoustic conversion efficiency (ACE) were evaluated in every step of conditioning. The decreasing of EMC by both thermal treatment is significant, the specimen modified at 180oC showed about 36% lower EMC at 60% relative humidity, the treatment by 200oC brought about 42% decreasing of EMC. Both treatments significantly affected EMC but the effect on acoustic properties was not statistically significant, however, the changes for 200oC treated group were more perceptible. Acoustic properties were compared at every step of conditioning too. Dynamic moduli and ACE decreased with higher EMC and the damping increased for control group and both modified groups.

Název v anglickém jazyce

Effect of Moderate Thermal Treatment on Properties of Resonance Spruce for Piano Soundboard

Popis výsledku anglicky

Thermal modifications of wood could provide perspective way to reduce negative effect of moisture on musical instruments. Resonance spruce (Picea abies L. Karst) used for soundboards is characterized by high sound velocity in longitudinal direction, low internal friction and high specific dynamic modulus of elasticity. The moderate thermal treatment with steam protection can maintain original acoustic properties with significant influence on equilibrium moisture content (EMC) and dimension stability. To test the effect of thermal treatment the 3 groups of specimens (44mm x 450mm x 12mm) of resonance wood selected from piano soundboards manufacturing have been prepared (un-treated, 180oC, 200oC) and conditioned in 20oC and relative humidity steps of 40%, 60% and 80%. The relative weight loss 4.7% and 7% was achieved by modifications at 180oC and 200oC respectively. EMC, longitudinal and bending dynamic modulus of elasticity, logaritmic decrement of damping and acoustic conversion efficiency (ACE) were evaluated in every step of conditioning. The decreasing of EMC by both thermal treatment is significant, the specimen modified at 180oC showed about 36% lower EMC at 60% relative humidity, the treatment by 200oC brought about 42% decreasing of EMC. Both treatments significantly affected EMC but the effect on acoustic properties was not statistically significant, however, the changes for 200oC treated group were more perceptible. Acoustic properties were compared at every step of conditioning too. Dynamic moduli and ACE decreased with higher EMC and the damping increased for control group and both modified groups.

Druh

O - Ostatní výsledky

CEP obor

—

OECD FORD obor

20502 - Paper and wood

Projekt

<a href="/cs/project/TH02010978" target="_blank" >TH02010978: Eliminace vlhkostního zatížení hudebního nástroje</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2020

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů