Investigation of using Typha latifolia fibers to enhance polyurethane foam’s sound absorption properties.
Linjala, Juha Mikael (2021)
Linjala, Juha Mikael
2021
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-202105107950
https://urn.fi/URN:NBN:fi:amk-202105107950
Tiivistelmä
This study focused on measuring the sound absorption property of Typha latifolia fibers, and to investigate its use on enhancing polyurethanes’ sound absorption properties. Typha latifolia (Broadleaf Cattail) is a common perennial marsh, which has been used in many applications. In Germany, Typha latifolia’s insulation and acoustic capabilities have been titled as revolutionary in wall panel technology. Polyurethanes are one of the most versatile materials in the world. One of the applications where polyurethanes are being used, is sound insulation. Finding a way to lower the use of polyurethanes and replacing them with a greener alternative, which could potentially have the same sound absorption qualities, is always an attractive study subject. The fibers were extracted from Typha latifolia leaves by retting. The retting was done in a 100-degree water-sodium hydroxide-solution (98 % H2O, 2 % NaOH). Half of the fibers were separated by hand, and the other half was separated by using a carding tool. Hand separation kept the fibers longer and thicker compared to fibers that were separated with a carding tool. The sound absorption measurement was executed only for Typha latifolia fibers due to budget and schedule reasons. The sound absorption property of Typha latifolia fibers was good. The good result can be explained by material’s porous, wool-like structure. Part of the fiber’s environment friendliness is its biodegradability. Fiber’s biodegradability was investigated by placing the fibers into a com-poster for four weeks. The experiment was done in winter circumstances, and despite of challenging conditions, it was proven that the fibers will decompose just in four weeks. Closed-cell MDI-polyurethane foam, provided by Kevra Oy, was used in this study. Polyurethane’s cell structure was modified to be more porous, by using a water blow-method, which improved material’s sound absorption property. Adding Typha latifolia fibers to a non-modified polyurethane did not open the cells of polyurethane, which meant that composite’s sound absorption property stayed poor. Water-blown polyurethane’s structure was ideal for sound absorption purposes. It was challenging to create a homogeneous mix from Typha latifolia fibers and water-blown polyurethane, and the enhancing effect of Typha latifolia fibers to material’s sound absorption property was left as questionable. Typha latifolia fibers stood out from other natural fibers with their capability to create a strong bond with polyurethane. Next logical step would be to investigate if Typha latifolia fibers are suitable for making a textile.