New Edger and Upgraded Trimmer Are Paired with INOVEC WaneMaster and TrimMaster Optimizing Packages
CLARKSVILLE, Tenn. — Whitson Lumber Company is a hardwood grade mill with an 86-year history in the forest products industry. The company has seen an incredible amount of change in its operations and in the industry.
In order to thrive throughout the years, Whitson Lumber has continually adjusted its approach to milling to ensure that it can provide its customers with quality products efficiently and cost-effectively, according to general manager Mike Nesmith. This year the company made improvements to its mill, mainly through upgrading the edger and trimmer operations. Whitson Lumber invested in a new edger, refurbished and modernized its existing trimmer, and installed INOVEC optimization technology on both. The improvements resulted in a significant increase in both product volume and quality, said Mike.
Whitson Lumber is a third-generation, family-owned business that was founded in Nashville in 1914. The company opened a second mill in Clarksville, some 45 miles north near the Kentucky state line, in the late 1950s. It operated the two sawmills for more than 40 years until a decision was made three years ago to consolidate milling operations into one highly modernized facility to be located in Clarksville.
The mill saws the whole variety of hardwoods available at the heart of the nation’s hardwood belt. The primary species are red oak, poplar and white oak. The company produces random width and random length grade lumber for the furniture manufacturing businesses in the region, and 4×6 center cants are sold to pallet companies.
Three procurement foresters are responsible for keeping the mill supplied with logs. Whitson Lumber reaches out as much as 120 miles for fiber, although most of the supply comes from within 75 miles. About 40-50% of the mill’s raw material comes from standing timber purchased for harvest and the rest comes mainly from logs bought from local contractors. Whitson Lumber owns a limited amount of forest land from which it harvests some trees.
Logs are unloaded utilizing a Komatsu and CAT log lifts and are scaled. The results of the scaling are entered into a hand-held computer. Each log is tagged so that it can be tracked through the mill, and production records are kept on each log. The data collected is used to fine tune the mill’s operations on an almost minute by minute basis.
Logs are sorted by species, then placed in inventory until they are scheduled for milling. Processing begins when the log is debarked on an HMC rosser-head debarker. The log then is conveyed to a 7-foot, Salem head rig and carriage for primary breakdown and then a 7-foot Salem line bar resaw with a cant turning station. Secondary breakdown is accomplished with a Salem thin-kerf gang saw, and the material goes to the edger and trimmer.
Whitson Lumber invested in a new Timber Machine Technologies edger. It was coupled with INOVEC’s WaneMaster hardwood edger optimizer package.
The company also turned to Timber Machine Technologies to upgrade its trimmer. The refurbished, modernized trimmer was paired with INOVEC’s TrimMaster hardwood trimmer optimization package.
Residual wood fiber is marketed one of several ways or used by Whitson Lumber for its own operations. Ninety percent of the sawdust is sold to the pulp market. Trimmings and bark are processed in a Precision chipper, and the bark is sold for mulch. Some wood material is used to fuel Whitson Lumber’s dry kilns.
While the milling processes at Whitson Lumber’s mill are pretty similar to other hardwood sawmills, the company pays extraordinary attention to its manufacturing operations, as evidenced by its most recent investments to improve edging and trimming.
The improvements were part of a comprehensive plan to maintain the company’s competitive position. The plan began to unfold three years ago with the decision to consolidate production at Clarksville. “We began to modernize with some goals in mind,” said Mike. “We wanted to bring our production capacity into the 24 million board feet per year range. And in order to compete in today’s markets, we thought we had to do that with as little resource as possible. We were facing timber prices that were going higher and higher while, at the same time, margins were shrinking.
“In order to compete,” he continued, “we decided we had to be able to squeeze the most yield possible out of each log. We wanted to begin to convert more raw material into lumber rather than into chips. It only makes sense. If you are getting $16 per ton for chips and $150 to $200 per ton for lumber, any additional lumber production you can get out of the same log is a better opportunity to make a reasonable profit on your operation. You can only do that with a modern mill.”
In modernizing the mill, Whitson Lumber made modifications in three major areas of its operations. On the mechanical side, new or refurbished equipment, such as the edger and trimmer, was added so that logs could be processed to the exacting tolerances required in order to recover the maximum amount of fiber for lumber production. To ‘tell’ the machines and the operators how and where to saw for the best results, optimization packages were installed to increase utilization and provide consistent quality. Lastly, the mill began to use Statistical Process Control in order to measure moment-by-moment how efficiently the mill is running; Statistical Process Control also helps the company to make incremental changes to increase productivity.
The machinery supplied by such companies as West Salem, Timber Machine Technologies and others provide high production milling within the narrowest tolerances.
Whitson is using optimization technology to maximize yield and — of equal or greater importance — to increase control over quality. The INOVEC WaneMaster, installed on the company’s edger, for example, allows mill management to determine what cutting rules to use based on market demand, lumber value, and other parameters. After mill management sets the values that it wants maximized, the WaneMaster program examines each flitch it receives and develops an edging solution to achieve the most value from that flitch, based on the rules set by managers. “This gives us close control over the quality of the product,” Mike said. Similar improvements are achieved in trimming using the INOVEC TrimMaster package.
The Statistical Process Control system was developed and installed in the Whitson Lumber mill in partnership with the University of Tennessee, which is using the mill to help develop a finely tuned methodology for controlling milling processes. Because each log is tracked throughout the entire breakdown process, the system keeps and monitors an up-to-date record of where a log has gone and what it produced. The data is then analyzed and compared with standards that are based on previous production levels of similar logs. The analysis can detect even small variations from expected outputs — variations so small that the cause can be pinpointed and corrected before it begins to substantially impact production. If a blade needs sharpening or a bearing is beginning to wear excessively, for example, the impact will be detected and the problem can be corrected early, before major reductions in production begin to occur. Similarly, corrective actions can be tried and found to be effective or wanting using Statistical Process Control.
The combination of optimization technology, Statistical Process Control, and new and upgraded equipment has resulted in noticeable reductions in overall target size variations in finished products. The mill has recorded improvements of 30/1000 of an inch in standard deviation. As Mike noted, an improvement of 30/1000 of an inch can reduce by 3% the raw material required for a certain output, so the mill can reduce raw material costs significantly while at the same time maintaining desired production levels.
Exact measurement of production improvements in a mill utilizing optimization technology is subjective as much as objective, said Mike. He was reluctant, therefore, to pinpoint a particular percentage of improvement as a result of the mill’s new optimization technology. However, one measure of the application’s successful performance is quite clear. “Our chip production really tells the story of the improvements we’ve seen,” he said, “especially since we’ve added the edger and trimmer optimization. What we have seen is approximately one load of chips disappear per day with the new equipment, and what that means is one load of chips is now going into lumber.”
The new INOVEC optimization technology has exceeded the goals set by Whitson Lumber. “We projected a very rapid pay-back and it has met our projections,” said Mike. “We believe the pay-back for our operation, based on the production we’re seeing, is going to be less than three years.”
Asked what advice he could pass on to others about selecting and utilizing optimization technology, Mike suggested that anyone considering upgrading a mill should visit other mills with optimization and talk with those who are responsible for it. Mill owners or managers need to examine their operations and understand what their goals are, he said. Then go out and see what kind of equipment is available and how it can be integrated to achieve those goals. It is also important that the mill has adequate output to justify the investment, he added.
As can be seen by its modernization program, Whitson Lumber Company has found that carefully planned adjustment to change leads to success. The company has seen two major industrial revolutions during its history. When the company was first established, America was in the middle of a shift from horse power to machine power. Today, the nation is learning how to integrate the computer revolution into industrial operations. In making the adjustments necessary to benefit from revolutionary technology, progressive companies like Whitson Lumber assure they will continue to survive, thrive, and participate in the new opportunities to serve the customer that another century will bring.
