Dimensional changes of waterlogged archaeological hardwoods pre-treated with aqueous mixtures of lactitol/trehalose and mannitol/trehalose before freeze-drying

The article presents research on changes in the dimensions of waterlogged archaeological oak and beech wood pre-treated with aqueous solutions of either a mixture of lactitol and trehalose or a mixture of mannitol and trehalose, and then vacuum freeze-dried or dried with the use of the conventional air-drying method. Uptake of impregnants, shrinkage and moisture content in wood after freeze-drying, and changes in dimensions and moisture content in all modified and dried wood samples after its seasoning in the air at relative humidity 50% and temperature of 18 °C were determined. It was shown that even at a low uptake of lactitol/trehalose or mannitol/trehalose mixture and vacuum freeze-drying, a considerable reduction in the shrinkage of the wood under research could be obtained.