canfor-new south makes curves with gen-II gang
canfor-new south makes curves with gen-II gang
“ Recovery in yield as well as value has a great importance . Good optimization is critical to reducing the amount of wane and producing higher value lumber with minimal loss in yield .”
The test of time has proven the benefits of curve sawing , producing straighter , stronger , longer lumber . Curve sawing and USNR ’ s GEN-II gang has reshaped the industry .
It is well known that technology can have a major impact on a mill ’ s efficiency and ability to be profitable . Canfor-New South , Conway , SC chose to upgrade its gang system from straight sawing to curve sawing to take advantage of the benefits that curve sawing affords , including the ability to buck logs to longer lengths , improve recovery and produce straighter and stronger lumber .
General Manager Tim Papa and his team were looking to improve the mill ’ s performance with systems that offer higher throughput , improved recovery and more flexibility for the future . The team reviewed other “ wiggle box ” gangs on the market , and selected the GEN-II gang for several reasons . They toured other mills , observed the GEN-II in operation and liked what they saw in terms of quality , performance and value for the investment . They also had confidence in the USNR team from several past successful projects . Canfor-New South now has three USNR curve sawing gangs in operation at various sites .
The team decided to go with a lineal scanning configuration because it worked well with their plans for the layout of the mill , allowed the capability to have a single operator for both log and cant breakdown , and offered an additional 1-2 % recovery over transverse scanning .
Tim and his team wanted to invest in curve sawing technology because of the substantial improvement in yield it offered . Looking to the future , Tim knew that newer systems also offer greater flexibility to accommodate technology advancements . The lineal system requires less maintenance and is less labor intensive than the transverse configuration . The GEN-II gang is more powerful than its predecessor at Conway , offering higher throughput which alleviated the bottleneck that developed when the mill ’ s sharp chain system was installed .
GEN-II features
The GEN-II gang is the latest generation from the curve sawing revolution that re-shaped the industry in the 1990s . The design of the GEN-II features the skewing and slewing CNC saw module . This allows the saw cluster to move side-to-side ( slew ) and pivot ( skew ) to match the curve of the cant . Chipping heads located ahead of the saws develop the face on the side boards .
The Conway machine is a double arbor configuration with two sawing zones for 10 saws in each zone . It processes cants up to 12 ” thick x 24 ” wide x 20 ’ long . The infeed and outfeed sections use heavy , driven feed rolls and chain beds to stabilize the cant during processing . A clamshell opening and moving saw box create easy access for maintenance and saw changes . The GEN-II design offers large chip heads to allow greater chipping depth with less lateral forces than the earlier model . The GEN-II also allows shorter cant gaps , higher piece counts and quieter operation . The Conway gang was not outfitted with profilers , so the lumber is discharged onto a sorting station where boards with wane can be dropped out and routed to the edger .
Optimization
The optimization software enhances the benefits of curve sawing , and allows the mill to match its products to ever-changing market requirements . The system ’ s path generator software allows compound curve evaluation with control of the cant curvature to ensure smooth lumber flow through downstream equipment . Cut logic for edging and trimming is considered in the solution and supports extensive simulations on saved or simultaneous scan data . The standard SQL interface allows integration into a centralized mill management system . The PLC system and interface is A-B ControlLogix which offers fast processing time , short cant gaps and easy troubleshooting .
Staying competitive
When asked what it takes to run a successful mill operation through the tough times , Tim made the following observations . “ Log costs are a big issue , accounting for 60-65 % of the cost of producing lumber . This means the raw resource is like gold , and recovery in yield as well as value has a great importance . Lumber buyers are conscious of the appearance of the product . Good optimization is critical to reducing the amount of wane and producing higher value lumber with minimal loss in yield .” Smart managers like Tim Papa and his team are looking to technology to help them stay competitive .
ISSUE 3 - 2013 | Millwide INSIDER 19