Tracing thermal treatment in wood using RFID

In order to detect previous thermal handling and treatment in sawn wood and wood packaging materials, radio frequency technology can be used. Wood pieces in which thermal sensor were embedded, were cured in 56 o C temperature for 30 minutes and then were laid for a period in external conditions. Thermal treatment process and any other information saved in the implanted microchip was possible to be recalled, using radiofrequency technology. Respectively, wood specimens with embedded temperature sensors were cured simulating a wood drying program for one week period. All information regarding the course of temperature was possible to be regained using radiofrequency technology. The specific technology seems suitable to contribute in tracing thermal treatment that has been applied in sawn timber and wood packaging materials. 1 Introduction In wood conversion process the application of high temperatures is necessary, a lot of times. Thus, in a lot of procedures such as wood drying, unreeling, decorative veneers production, wood bending, wood covering using thermoplastic glues, etc. temperatures much higher than those of the environment are applied. These temperatures are associated either to physical properties (e.g. wood moisture content drop, advancing of wood elasticity) or to chemical procedures (e.g. glue curing). As wood is a thermal insulating material, heat transmission delays and in wood core can’t always be obtained the same temperatures, compared to those of the surface. So, the main goal for which wood is heated maybe not be achieved and for this reason temperature monitoring in solid wood core or in wood panels core is many times imposed, not only for laboratory processes but also for ascertaining industrial processes. The particular question (warming up to specific temperatures) is quite crucial during thermal treatment of wood that is intended to be used for wood packaging material or during thermal treatment of ready wood packaging material. The spread of the nematode Bursaphelenchus xylophilus in conifer forests has imposed internationally urgent measures to be taken, for the sterilization of lumber. In this case temperatures over 56 o C are needed in the core of wooden pieces with the larger cross sections, for a period at least 30’ (FAO, 2002). In most of the cases, lumber that has been kiln dried is assumed that covers the requirements of FAO’s International Standard ISPM 15 but this depends on drying method, as there are drying methods where lower temperatures are applied (e.g. dehumidification). It depends also on the initial