津波等で被災した文書等の救済法としてのスクウェルチ・ドライイング法の検討

摘要

When paper documents are affected by water damage, such as flood and tsunami, it is thought that some microorganisms grow rapidly and cause biological deterioration. As a way to restore wet paper documents, there are some approaches such as air-drying and freeze-drying. In the present study, the squelch-drying technique using books experimentally immersed in salt water was examined to assess the applicability of this method to wet paper documents affected by tsunami. The squelch-drying technique used in this study consisted of the following three steps: 1. cutting polyester sheets and newspaper according to the size of books; 2. wrapping each book with a layer of polyester sheet and some newspaper, and putting it into a plastic bag; 3. sealing the bag with a heat-sealer using a vacuum pump or a vacuum cleaner. As a result, the squelch-drying technique could significantly reduce crinkles and wavy state of the paper of the books, which is often observed with air-dried books. Furthermore, this technique is expected to reduce the residual salts of seawater from the books. However, this technique requires considerable time and labor because it is necessary to repeat the above steps until the books are dry. Also in case of saltwater-soaked documents, longer time is required to reduce the weight of the documents, compared to the cases of documents soaked in distilled water. Nevertheless, squelch-drying technique can provide a promising way to rescue wet documents where no refrigerator or freeze-drying machine is available at the time of disaster.%スタウェルチ・ドライイング法は，本の大きさに合わせて新聞紙を切り，新聞紙を定期的に 取り替えるなど手間と人手を必要とする。しかし，風乾と比較して，本全体からゆっくりと脱 水するために，処理後の紙の波打ちを防ぐことができる。新聞紙を取り替えるタイミングや量 を工夫することにより，処理期間を短くすることもできる。 また，何よりも冷凍庫，真空凍結乾燥機などがなくても処理ができるため，処理の選択肢を 広げる点で大きな意味がある。