LOG CONDITIONING BEFORE MECHANICAL DEBARKING

摘要

High powered lasers are used to score the bark (28) on logs (26) before they are mechanically debarked. Typical of the lasers employed are multi-kilowatt CO2 industrial lasers. A high powered laser beam (20) is brought to a focus just above the surface of the bark (28) on the log (26). A jet of compressed air is blown co-axially with the beam and facilitates the beam's formation of a narrow slot in the surface of the bark. Logs are advanced and rotated by a plurality of parallel augers (42) extending across the base of a trough (40). The lasers are positioned in a gap beneath and in between sets of augers. The beam's focus may be adjustable with respect to the bark's surface. The motion of the log with respect to a laser head produces a spiral cut along the surface of the log which slices the long fibers in the bark.