The Latest and Greatest
Scanning and optimization technology is constantly changing as companies develop new software and hardware.
by Treena Hein
"Fifteen to twenty years ago, we saw the first scanning and optimization systems that could control the mechanical positioning equipment to maximize log value," says Francis Fournier, Eastern manager of lumber manufacturing at Canadian forest research institute FPInnovations. "Maximizing what to take from each log was the first 'level' this technology provided as well as identifying significant defects. Now it's going beyond this to identifying fine defects and wood attributes (moisture content, mechanical resistance) at the start of the value chain."
This creation of better scanning and optimization technology to be used at the start of the value chain evolved from a drastic change in the forest products industry. "For the past 20 to 30 years, we've manufactured products and tried to sell those products," observes Fournier. "Now lumber producers are more and more client-oriented. They work backward to produce products that exactly meet these needs in terms of quality and adding value."
While 'scanning and op' technology may be expensive to replace - and operations in Western Canada may have more opportunities to upgrade because of recent booming sales to Asia - the latest versions of scanning and optimization technology allow for quicker payback than ever. All new scanning technology reflects the fact that the more points that are measured along the log, the greater the cost. More expensive optimization equipment is more specific - detecting slight coloration changes that indicate shake, rot and cracks and more - and may also take into account what orders have been placed (or are usually placed). The most advanced and expensive equipment will also measure on the fly, because processing speed is everything in safeguarding profits. Fournier notes that more accuracy and consistency is also desired. Eventually, it's predicted that "intelligent" sawmill-planer mill operations will be developed, where all scanners are tied together and decisions are based on integrated feedback from all points.
In the following article, we take a look at some of the new sawmill advancements, and in the next issue, we will look at planer mills.
Inside the Sawmill
Conifex uses a variety of scanning and op technology brands and is in the midst of upgrading in some areas. At their Fort St. James, B.C. sawmill, they use a Porter op system for log-bucking. "It has plenty of flexibility and a good user interface," says Ron Mohr, corporate quality control. "The headrig has a very old op system and we have no plans to upgrade this as we'll eventually replace the whole line." The small log canter/quad has also has Porter op and the large log canter/quad uses Nelson Bros. "We're very close-coupled and didn't have room for a full doublelength in-feed," says Mohr. "It's not the most flexible system and unfortunately we have to rely on the operators for manual rotation of the logs, but it does a very good job considering the restrictions it has to work with." The edgers and trimmers use USNR/Newnes op, which Mohr says works very well and will soon receive upgrades. At their MacKenzie, B.C. sawmill, they have no bucking optimization as they use a cut-to-length log delivery system. The small log Profiling- Curve Sawing Canter uses Comact op, which Mohr says has been doing a great job, and the large canter/quad uses very old Porter op which will be upgraded soon. The edger and trimmer use USNR/ Newnes optimization, which also work very well.
"On each production line in the Mackenzie sawmill we use Si-Cam real-time size control, a new system for us that has already shown benefits," says Mohr. "This system provides us with uniformity of manufacture, improving product quality, customer satisfaction and increased grade recovery." There are alarms which notify mill personnel immediately when a sawline is cutting out of its control limits. "We can react immediately, reducing the number of mis-manufactured pieces," Mohr notes. "Traditionally, we relied on operators to notice any mis-manufacture in the plant. However, a large volume of lumber can be produced prior to any operators getting a close look at the lumber. Also, at production speeds, the operators don't always get a really close look, so potentially we could produce lumber slightly out of our control limits for some time before it's caught." He notes that while they do have 'size control' personnel who manually measure pieces from each sawline, it can be quite some time before they get back to check the same sawline again.
New Developments
It was about eight years ago that scanning and optimization companies started putting effort into planning mills because most of the sawing process was already optimized, notes Francois Gigučre. "In the planer mills, humans were still needed since grading is one of the most important parts in the process," says Gigučre, a wood process optimization specialist with Prologic+. "Since then, we've seen new automatic grading systems installed in planer mills equipped with HD vision cameras and scattered laser for 3-D profiling. Prologic+ has brought part of this technology to the sawmill process."
Gigučre says there are many benefits to using their 3-D and Trueshape linear scanners. "Prologic+ scanners can detect many defects that were long ignored at primary breakdown," he notes. "These defects are log cracks, bark and surface knots." Some of the company's linear log scanners are also equipped with vision. "For example, log cracks can be detected across the length of the log and provide a new rotation considering this," Gigučre says. "This provides new ways to obtain extra profit." Their scanning system differs from others on many points, he explains, but the main one is the customization they can achieve with their software, providing exactly what the customer needs.
Sales of JoeScan's JS-20X3 scanner have taken off in the past year, with 146 units sold in the past 12 months," says JoeScan President Joey Nelson. "The JS-20X3 is designed for snapshot scanning systems with lasers on six-inch spacings," he says. "This doubles the scan density from the previous 12-inch model, while maintaining the Ethernetbased interface common to all JoeScan scanners." He adds that sawmills are finding the increased scanning density is a big benefit for carriage head-rigs, and other short-infeed log systems.
Comact's GradExpert optimizers can now scan log ends to help find the best cutting patterns, says Stéphane Desjardins, optimization operations manager. Comact is also working on technology which can detect cracks along the logs by scanning whole logs. "Splits, blue stain, pith, heart wood, sap wood, and knots are now identified and taken into account when the log is optimized," he notes. "In addition to log-end scanning, cant scanning and grading is offered as well. It uses visual defect detection to get the best productivity from your cant processing." Comact's board edger and trimmer optimizers are now offered with vision (commercialized as TrimExpert tm and EdgExpert tm), and every system performs in softwoods and hardwoods."
From USNR comes their Precision Geometric Log Rotation (PGLR) system, a real-time rotation verification and correction system that works on dual, quad roll or donut log-turners, enabling users to convert a manual system to a semi-automatic system or a semi-automatic system to a fully-automated precision log-turning system. It uses the same standard TriCam scan zone that the MillExpert log-turner uses, says senior marketing associate Colleen Schonheiter. Sawmill optimization situated upstream or downstream of the turning rolls actively monitor and correct positioning during and after the turn. The precision geometric log rotation system simultaneously verifies the accuracy of the autorotation system and automatically makes any necessary corrective turns.
Autolog now offers colour vision transverse trimmer and edger optimizers for sawmills. "Geometrical profiling (3-D) and colour vision (2-D) are combined in the same sensor," says Sales Manager Gabriel Payant. The 3-D geometric scanner consists of one single bar-coded laser system and 2-D scanning is achieved with two colour CCD cameras with LED lighting. Length resolution of the scanner is 1/4-in. (no light curtain required). The sensors are mounted at 45 degrees with the wood flow to measure all four sides of the boards, and this also reduces cleaning requirements. The 2-D vision detects knots, splits, shakes, bark, stain, grub holes and more. Payant says the software is based on the Autolog Prograder linear planer optimizer and offers the same features and advantages: powerful analysis of optimized solutions, SQL data base, simulation package, extensive reporting, user-friendly interface - and the same computer technology: industrialgrade servers with dual power supplies and hot-swappable hard drives housed in an environment-controlled cabinet.
MPM Engineering has developed a new log grading system called TrueGradeŠ that combines high-density 3-D geometric data with advanced surface image data to produce a true surface representation of the wood. "This system measures standard geometric log features including diameter, taper, sweep, flare, cat face, broken ends, etc., says sales and marketing manager Dick Komori, "but also provides positive identification of bark, knot whorls, individual knot sizing and classification by considering how the laser reflects on the wood's surface." It can be applied to log merchandizing and sorting, optimized log rotation, primary log breakdown and cant optimization. TrueGradeŠ system can detect sap pockets, rot, heartwood/ sapwood boundary, pith, metal, stones, knots and knot volume, cracks, density, and structural strength. Internal images are overlaid with the high-density geometric laser scan data, producing a full external and internal 3-D image. MPM is also developing a universal interface that can accept data streams from third-party vision systems (such as a CT scanner) for internal defect detection.
SOFTAC Systems Ltd. has been supplying sawmill and planer mill optimization systems for softwood and hardwood for over 25 years. "In addition to providing accurate, dependable laser scanning systems, SOFTAC offers expanded software programs for inventory management control, extensive lumber tally reporting and lineal grade scanning for planer mills," says president Ian Bowman. "Manufacturing our own line of scanner heads allows us to provide continual support and service on all system hardware including PLC systems and Sorter Controls." Bowman sees the future needs of both sawmills and planer mills including customized systems to meet global demands for specific products and real-time inventory control. "We also see a need for mills to replace expensive manual handling tasks with more efficient automated grading and sorting systems," he adds.
Having successfully graded dimension lumber at continuous planer production speeds of 3,800 feet/minute, Lucidyne Technologies Inc. is looking for an opportunity to take the same technologies to the sawmill edger and trimmer. "We offer both a lineal and a transverse scanning system," notes Bill Briskey, director of marketing & sales, "the former being aimed at more difficult fibre challenges and the later designed to identify a smaller set of fibre characteristics. Identifying shake, knots, and decay early in the life of a board can make a huge value impact for a mill by better directing its edging, trimming, and drying phases."
Nelson Bros Engineering designs scanning and optimization for every machine center in the sawmill, from a basic lineal board edger to a state of the art log processor with auto-rotation, says spokesperson Jeff Nelson. "Nelson Bros offers free telephone and online support for the life of the system," he notes. "Furthermore, Nelson Bros, products have straightforward software and the fewest parts for easy maintenance and lasting recovery improvement."
Salem Equipment Inc. has developed infeed systems that support most scanning system suppliers, systems that take the best advantage of available technology," says sales manager Dave Butler. "Salem's feed systems and machine centers allow for 'snapshot scanning' for instance, in cases where mill space does not exist for traditional lineal or transverse scanning applications," he says. "Salem also optimizes production rates by using scanning data to control feed speeds."
With a 35-year history in the sawmill industry, LMI Technologies has developed a line of 3-D sensors for all areas of the sawmill. In addition to very high density 3-D profiles, their DynaVision chroma+scan 33xx transverse board scanners allow customers to choose integrated full colour images with 1 mm x 0.5 mm resolution to detect surface defects, or a scatter laser to detect knots, surface defects and grain angles. "What differentiates the DynaVision chroma+scan 33xx is the options it provides, along with high speed and high quality of data," says VP of Marketing Barry Dashner. "Combining multiple functions in a single sensor ensures data integrity while reducing costs with installation and maintenance."
LMI's DynaVision chroma+scan 20x5 lineal high-speed log scanners provides 360? 3-D profiles with laser scatter detection available to measure surface characteristics including knots and cracks. "Dual cameras, one on each side of the laser line, ensure that there is no missing data due to defects occlusions such as knots on the log surface or conveyor flights that cause data dropout with single camera scanners," notes Dashner. "Our DynaVision chroma+scan 2400 family of scanners for carriages add the ability to select laser lines every 6" or 12" at a scan rate of 120 Hz, which supports scanning both the front and back of the log on the carriage." This provides very high density 3-D profiles down to 1/2" along the log, front and back, resulting in higher recovery.
Watch for our July/August 2011 issue for information on scanning and optimization in the planer mill.
