Liquid impregnation into dry wood using a roller-pressing method, 2: Effect of specimen size and processing variables on amount of water impregnation
2004
Adachi, K. (Tokyo Univ. (Japan)) | Inoue, M. | Kawai, S.
Knot-free flat sawn sugi (Cryptomeria japonica D. Don) lumber prepared with moisture content of 12% and various dimensions was impregnated with liquid by using a roller press under the following processing variables : compression degree, soaking lime, feed speed, and cyclic loading. The amount of water impregnated and changes in bending properties due to under-liquid roller pressing were investigated. The results are summarized as follows : 1) For specimens less than 500 mm in length or less than 6 mm in thickness, the amount of impregnated water increased in inverse proportion to thickness and length of the specimens. Bending properties decreased in inverse proportion to specimen size. 2) The rate of increase of the amount of impregnated water increased with the degree of compression. 3) Change of feed speed in the range from 1 to 12 m/minute did not affect the amount of impregnated water and the bending properties, 4) The amount of impregnated water increased by cyclic compression. The bending properties of 8 mm-thickness decreased with increasing number of 60% -compression cycles. The condition of strength reduction by cyclic compression was paralleled by high frequency of occurrence of longitudinal splits and surface checks.
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