美国明尼苏达大学林学院林产研究所,把低温处理应用于木材干燥,取得良好的效果。其方法:即木材在干燥以前先进行预冻处理,使之完全结冻,然后再进行人工干燥。冷冻剂使用一般的液体氮,其降低温度可达到-320°F。他们就美国红杉和黑核桃两种树种进行了大量的试验。对2.54厘米和5.08厘米厚的板材,其预冻温度以-100°F为宜。对其他树种和不同厚度的板材,其预冻温度也不一样。木材经预冻处理后,即可进行干燥。试验证明, Forest Research Institute of the University of Minnesota, the United States, the low temperature treatment applied to wood drying, and achieved good results. The method: the wood is pre-frozen before drying, so that it is completely frozen, and then dried manually. Refrigerants use general liquid nitrogen, which reduces the temperature up to -320 ° F. They conducted a lot of tests on both American Sequoia and Black Walnut species. For plates 2.54 cm and 5.08 cm thick, the prefreezing temperature should be -100 ° F. For other species and different thickness of the plate, the pre-freezing temperature is not the same. After the wood is pre-frozen, it can be dried. Test proved that,