Quite often people face problem which consists in drying of oak timber. The fact is that the oak badly gives in to drying process. On this material external and internal cracks can easily be formed. Especially great difficulties arise when drying green oak timber humidity over 25%.
1. Extremely it is not recommended to dry oak which was sawn recently. It is the safest to make drying of thin materials which have humidity from 40% and below. In modern dryer units there are programmable devices which allow to support certain dependence of climate in the camera from humidity of the dried-up material.
2. The climate in the ordinary drying chamber is defined by temperature and gradient of drying. Also the climate can be defined by temperature of the "dry" and "wet" thermometer. Everything depends on what device management the dryer has. Programs are usually used the identical or having similarities.
3. In the program of drying it is possible to allocate several phases. Two phases from them are taken away under drying. In the first phase the drying from initial humidity to 26-30% is carried out. There is it at rather low temperature and gradient. Throughout all phase these indicators remain invariable. In the second phase material dries from humidity of 26-30% and to final. Process is carried out at the increased temperature and gradient. Most often it is followed by growth of gradient by the end of drying. Also there are cases when with growth of gradient grows as well temperatures.
4. It is not so simple to dry oak. The fact is that there is wide spacing of humidity on all surfaces of green material. For this reason it is necessary to expose correctly moisture sensors on which management of drying will be conducted. The controller of the dryer according to average indications of moisture sensors will carry out switching from the first stage to the second. Switching makes when the humidity is 26-28%. In this case the probability of cracking of part of material which humidity exceeds the specified value is very high.