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No.64 (2017/12) >

 
Title :芭蕉布生産工程における木灰汁の果たす役割 : 大宜味村喜如嘉を事例にして
Title alternative :The role of Wood Lye in the Bashofu Cloth Production Process : A Case Study of Kijoka, Ohgimi Village, Okinawa, Japan
Authors :渦岡, 梓
仲間, 勇栄
陳, 碧霞
Authors alternative :Uzuoka, Azusa
Nakama, Yuei
Chen, Bixia
Issue Date :28-Dec-2017
Abstract :This study surveys the features of wood lye, which has played a key role in the production of Bashofu, a traditional textile nationally designated by Japan as an Important Intangible Cultural Property. This textile is made only in Okinawa, using fibers obtained from the stem of the Musa liukiuensis banana. The majority of the experimental samples for this study were collected from wood lye that was actually used to cook banana fibers at Kijoka Bashofu Kaikan, a local facility in Okinawa aimed at training the next generation of Bashofu-makers and serving as a public education center focused on traditional textile-making techniques. The pH of the wood lye from the Bashofu Kaikan facility varied from 11.5 to 12.5; however, the specific gravity was quite low, mostly ranging from0 to 0.4 degrees Baume. The experimental samples that we prepared, including second-time reuse of wood lye, a higher specific gravity of >1.0 degrees Baume. However, as the number of times of wood lye reuse increased, the specific gravity, as measured by the Baume scale, decreased. The quality of the wood lye declined as a result of a decrease in K, which is the major active component of the wood lye. Similar to the effect of increased wood lye reuse, the additional input of new wood lye to the reused lye led to an overall decline of lye quality. However, it should be noted that the Specific gravity as an indicator of lye quality is inappropriate for evaluating the reused wood lye because the ingredients released from the banana fiber during the cooking process also change the specific gravity. Using a method recorded in the historical document “Nantou Zatsuwa” (South Island Everyday Dialogue), we prepared lye from straw ash and obtained better-quality lye with higher pH and Specific gravity. Consequently, our study revealed that good-quality lye should have an appropriate Specific gravity ranging from 1.5 to 2.0. We adopted Specific gravity as an indicator of lye quality because it is related to the K value. Wood lye, which has a high K level that makes it alkaline, also has many components that can react with banana fiber. In order to obtain wood lye of good quality, it is vital to reduce the number of wood lye reuse cycles and to apply the indicators of pH value and Specific gravity when no new wood lye is added to the reused material. To that end, more wood ash is needed for efficient Bashofu fiber production. However, presently in Okinawa, it is difficult to obtain wood ash in such large quantities. Therefore, other means of obtaining wood ash should be considered to meet the larger demand. To maintain the quality of Bashofu cloth, good-quality wood lye is necessary. Thus, in the future, to improve the wood lye quality and effectively extract the lye, it will be necessary to explore the differences in the features of wood lye produced from different species of trees. Above all, ensuring a stable supply of wood ash is a challenge.
Type Local :紀要論文
ISSN :0370-4246
Publisher :琉球大学農学部
URI :http://hdl.handle.net/20.500.12000/40908
Citation :琉球大学農学部学術報告 = THE SCIENCE BULLETIN OF THE FACULTY OF AGRICULTURE UNIVERSITY OF THE RYUKYUS no.64 p.13 -27
Appears in Collections:No.64 (2017/12)

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