Impregnation of timber e.g. with insecticide or fungicide - by drying in a high frequency field, application of vacuum, treatment with impregnating agent, and application of pressure

摘要

The mechanically pre-treated timber is subjected to a preliminary drying, preferably in air, and is then further dried in a high-frequency field. Residual moisture and air or gas present in the timber are removed by vacuum drying. While maintaining the vacuum, the dried and de-gassed timber is completely washed with an impregnating agent and then the capillary pores and the solid substances of the timber are penetrated by the impregnating agent by rapid application of pressure, the impregnating agent being subsequently solidified. Protection of timber against the influences of moisture, insects, fungi etc. The process can also be used to improve electrical insulating properties, e.g. in the prodn. of electrically non-conductive railway sleepers. Process ensures that impregnation is complete, but the drying process is gradual, so that the splits do not appear in the timber.