On the frontline – SCANNING & OPTIMISATION
Accuracy, yield leap ahead for BC mill
For all sawmills today, the focus on limiting waste and getting the most out of each log is very much in the
forefront of the mill manager’s mind. At Carrier Lumber’s British Columbia operation,
USNR has been paramount in helping the owners achieve their motto: making every log count
an unprecedented market slump. Carrier Lumber’s Tabor mill at Prince George, British Columbia is in the heart of the beetle-killed region, and though times have been challenging, the company has continued to reinvest to remain as competitive as possible. Two new log breakdown lines were its latest pursuits, both equipped with smart technology to help achieve the greatest value and recovery possible from its logs.
M
Carrier history Carrier Lumber dates back to the early 1950s. It was founded by William Kordyban Sr and is still privately owned. In 1976, the company built on its current location and today it consists of a two line dimension sawmill, planer mill, dry sheds, a wood yard, and dry kilns.
The mill has continually upgraded equipment to enable it to maintain its reputation for producing high quality lumber, with output in the range of 220 million board feet/y and yielding 1x4 through 2x12 in 2.5 m (8 ft) to 6 m (20 ft) lengths of J-grade, Stud, 2&Btr, #3 and Economy. Logs are obtained through the mill’s timber licenses supplemented with private wood. The mill processes SPF logs with a 100 mm (4 in) top up to a 600 mm (24 in) butt.
any mills in British Columbia are persevering despite a devastating pine beetle epidemic followed by
Carrier Lumber’s mill in Prince
George, BC, features two log lines both of which use the PGLR turn correction system
Partnering Carrier Lumber has long advocated the ‘chip -n- saw’ style of log breakdown. The Tabor mill’s layout included two ‘chip-n-saw’ lines, one for small and another for larger logs. Several years ago the decision was made to purchase a new small log line. USNR’s vertical shape sawing (VSS) small log processor was the successful candidate for processing logs with smaller than a (10 in) butt, and was installed in mid-2008. Concurrently USNR was developing a new process for log turn verification, and Carrier agreed the Tabor mill should be a beta test site for the new process, dubbed Precision Geometric Log Rotation (PGLR), on its new small log line.
PGLR on small log line On the VSS line, geometric Smart TriCam sensors scan the log before it enters the infeed section to measure it and determine its position. The slewing and skewing infeed positions the log for the turn, then it is scanned again while being turned. During the turn, the PGLR’s Smart TriCam sensors are scanning the log continually and feeding the measurement data to the optimiser to instruct the PLC to correct the turn as the log proceeds through the turners. The log continues to be scanned until it is finally released by the turners. There is a full scan zone directly after the quad-roll log turner that confirms the log’s
FEBRUARY/MARCH 2012 | International Forest Industries 21
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