Wide-Ranging Speeds Important In Mill Motor
MRO MagazineIndustry Mining & Resources
T he largest fibreboard plant in North America and the third largest in the world is owned by Plum Creek Timber Company Inc. Plum Creek project engineer, Jack Hinman, faced a tremendous challenge when...
T he largest fibreboard plant in North America and the third largest in the world is owned by Plum Creek Timber Company Inc. Plum Creek project engineer, Jack Hinman, faced a tremendous challenge when he was asked to head up a five-person team to build the new plant and get it operational in less than a year. To accomplish the goal, the team looked for manufacturers that would act as its partner.
Plum Creek operates the second largest private timberland owner in the United States. Its plant is located in the small town of Columbia Falls, MT, not too far from Glacier National Park. Plum Creek’s products include furniture-quality veneer logs, proprietary plywood and specialty lumber.
For years, Plum Creek has held a leadership position in the medium dense fibreboard, or MDF, business. But back in 1999 it decided to expand its capabilities to produce an enhanced product line. In January of 2000 it broke ground and began constructing a new state-of-the-art facility to produce Super-Refined MDF-2, a proprietary engineered wood panel prized by woodworkers for its smooth unblemished surface.
Its US$69 million investment would represent a quantum leap in fibre refining technology, and it selected Reliance as its key motor supplier. Why? With a long history of using Reliance motors, Plum Creek engineers knew they could count on a product that would provide superior performance and reliability. But more importantly, it understood the company now behind the brand, Baldor, would continue to act as its trusted partner.
“It was a very fast track and we had only a limited number of people to work on the project; that’s why we turned to the product and the people we had experience with,” stated Hinman.
“We rely on the company for a lot of support. This Columbia Falls facility has used Reliance motors since 1974, we know the product well, we’ve had good luck with the motors, and that’s why we specified them in the new line.”
The team worked closely with its European OEMs to make sure they understood why Reliance motors needed to be included on the equipment that would be installed in Montana. “Our past successful experience using Reliance motors prompted us to specify Reliance as much as we could,” stated Hinman. “We told our OEMs overseas that we wanted equipment we could replace here, and we wanted something that we had good experience with.”
The centrepiece of the facility is a continuous press designed to specifically produce panels almost paper thin, in a variety of widths and lengths. The process control and refining systems are modelled after technology used in the pulp and paper industry, an exacting manufacturing process that assures a fine-fibred, quality panel.
This is where it uses Reliance 200-hp RPM AC Inverter Duty motors. The press has the capability of making boards from two and a half millimetres up to an inch and a half thick. But the range of speeds required from the motor to produce the different boards is dramatic. To produce the thin material, it needs to run 60 metres per minute, guaranteed throughout the process. The thicker material needs to be run at 10 to 20 metres per minute.
The RPM AC Inverter Duty motor is ideal for this application because it can operate at over 1000:1 constant torque, with special base speeds, and at a wide constant horsepower range. In addition, multiples of these motors can be controlled to operate in a coordinated way.
“It’s critical that the motor provide constant torque at all of the speeds we need for the process,” states Hinman. “The Reliance product is able to perfectly match the correct speed through the entire system, driven from the press as the master all the way to the end.”
Reliability critical to production
This line runs 24 hours a day and produces, on average, 110 ft of board per minute. It’s a highly profitable plant that produces $40 million a year in revenues. Plum Creek sells everything it makes and it doesn’t keep inventory on the floor. That means if the line shuts down for any reason, it loses money at about a rate of $2,000 per hour. In a competitive market with thin margins, a motor failure can cause disaster.
According to John Conner, Plum Creek’s electrician, that’s another reason why it keeps coming back to Reliance motors. “We track downtime with a very sophisticated automated system, so we are always identifying which components are giving us problems,” stated Conner. “Reliability is very critical, we’ve always had a good track record with Reliance motors, and that’s why we are sticking with them.”
Conner views Reliance as a long-term player in the forest industry and a company that is committed to the isolated regions where Plum Creek locates. That’s very important to Conner and other engineers at the plant.
“Who can we call in the middle of the night or on a Sunday afternoon to come help us? There are some folks that will do that, and some folks who aren’t set up to do that,” he adds. “Yes, the products are proven, but it’s the people that are really important. That’s why we keep coming back to Reliance motors.
Baldor’s Reliance RPM AC motor lines are distributed in Canada by RG Speed Control Devices Ltd. For details, visit rgspeed.comor use the reply card number below.
Reader Service Card No. 395
AC Motors Are Compact
The Baldor Reliance RPM AC motors offer compact square laminated steel frames for inverter duty and vector duty applications. They are available from stock in totally enclosed fan-or blower-cooled and drip-proof designs from 3 hp through1,000 hp.
They are designed to handle the most demanding high-performance industrial applications in frame sizes that are up to three times smaller than traditional NEMA or IEC motors.
RPM AC motors feature low-inertia for use on high-response applications and are optimized for use with adjustable speed drives. They offer big power in smaller frame sizes and high efficiency for energy savings.
RG Speed Control Devices Ltd.
Reader Service Card No. 399