|MCINTYRE, GAVIN - Ecovative Design, Llc|
|BAYER, EBEN - Ecovative Design, Llc|
Submitted to: International Conference on Natural Fibers
Publication Type: Proceedings
Publication Acceptance Date: 7/1/2019
Publication Date: 7/9/2019
Citation: Pelletier, M.G., Holt, G.A., Wanjura, J.D., Mcintyre, G., Bayer, E. 2019. Acoustic evaluation of a mycological bio-composite as a natural fiber alternative to petroleum based closed-cell foam. International Conference on Natural Fibers. 139. https://doi.org/10.1016/j.indcrop.2019.111533.
Interpretive Summary: This research is a follow up to value-added processing of cotton byproducts to produce acoustic panels for sound absorption. This research varies from the previous study in the amount of agricultural waste materials and mycelium used to make the acoustic panels. The previous research looked at using mycelium as a binder in producing acoustic absorbers comprised of 95-97% agricultural biomass with the remainder being mycelium binder. In this study, the amount of biomass and mycelium were switched (95-97% mycelium and 3-5% biomass). Similar to the previous results, the mycelium-based acoustic absorbers performed, overall, better than the conventional fossil-fuel based ceiling tiles, currently in use in most buildings, as well as cork and felt. The best absorption ranges was in the higher frequencies most often encountered in vehicles. The current challenge is increasing production of the material to accommodate commercial applications.
Technical Abstract: This research examines the use of a novel new renewable resource in acoustic absorption applications. The material being tested is an all-natural biopolymer that consists entirely of pure fungal mycelium that is cultured at elevated-temperatures from 30 to 35 C. in an elevated CO2 rich environment which causes the fruiting bodies to be completely suppressed. This new biopolymer provides an alternative to closed cell foams and synthetic honeycombs. The study examines the acoustical absorption properties of this material over the frequency range from 320 Hz to 4 kHz. The results of the study indicate this new class of pure mycelium foams is a sustainable promising bio-based all-natural fiber alternative for acoustic shielding products that can provide a sustainable alternative to traditional acoustic absorbers that are most commonly constructed with petroleum-based glues and synthetic fibers.