Fingerprint traceability of sawn products using x-r ay log scanning and sawn timber surface scanning

Traceability in the sawmilling industry is a concep t that could be used to more effectively control th e production process and the utilization of the raw material. The finger print approach is a traceability concept that rests on the idea that every piece of wood is a unique individual with unique pr operties and hence can be identified and separated if a sufficient number of these properties are measured accurately enough. This study was hosted by a sawmill in north ern Sweden and was aimed at making the fingerprint connection betw een logs and the center yield sawn from those logs using length and knot information. The 140 logs involved in the stud y were of Scots pine with top diameters spanning th e range from 153 to 213 millimeters. The center yield sawn from these l ogs was of two dimensions. The smaller logs (153‐18 7 mm) were sawn with a 2 ex pattern to 50 by 100 mm, and the larger logs (174‐213 mm) were sawn to 50 by 125 mm with apattern. The data from the logs were collected at the log so rting station by an industrial one-directional x-ra y log scanner in combination with a 3-D optical scanner. The data fr om the sawn center yield were collected by an indus trial cross-fed surface scanning system situated in the sawmill’s g reen sorting station. Both systems are used in the sawmill's normal continuous production. The results show that over 9 0% of all planks could be matched to the right log, which bespeaks a great potential for further development and reali zation of fingerprint tracing as a tool for process control and process improvement.