Extra cleaning steps and new press technology enable CanFibre to turn urban waste wood into value-added MDF.
By Barrett Kilmer
Outside CanFibre’s new plant in Riverside, CA, a Caterpillar tractor pushes wood scraps into a mammoth pile that threatens to overshadow the nearby mountains. The wood, which would otherwise end up in landfills, will be turned into MDF in the company’s state-of-the-art, $120 million plant.
While recycling the wood will help Southern California landfills reduce their solid waste streams, CanFibre executives hope it will also help increase the company’s revenue stream.
To accomplish this, CanFibre plans to promote its MDF’s “green” pedigree and to emphasize some of the product strengths that company representatives say result from its new pressing technology, such as high fiber quality and moisture-resistance.
Operations manager Larry Tinker says the company and the Southern California region have a shared interest in the project. “There is a demand for MDF and urban areas have a wood supply that they need to deal with.”
CanFibre plans to convert these scraps into more than 78 million square feet (3/4-in. basis) of panel product annually when the operation is fully ramped-up later this year. By the company’s own estimates, using post-consumer wood waste instead of virgin timber will save between 2,000 and 3,000 acres of trees per year.
Clearing the Air
“We are a unique facility for the district. We put out pollution below current measuring equipment’s allowable limits,” he explains. “They have a range of 1 to 10 and we come in at less than 1 so we are considered outside the normal allowable limits.”
Tavoda and others at the plant like to say that the air leaving their plant on a smoggy summer day is actually cleaner than the air taken in, though they admit the claim is perhaps exaggerated.
Environmentally responsible products are growing more and more popular with consumers, according to president and CEO Chris Carl, but he says the products stand on their own merit.
“We have found at trade shows and from talking to people that
The plant was designed so that it would tap into only 10 percent of Los Angeles County’s available waste wood supply. That does not include the surrounding counties, where CanFibre actually gets most of its wood.
“We don’t foresee wood supply as ever being a problem,” says Tavoda.
The Cleaning Process
After the scraps are sent through primary and secondary hogs, the small pieces are separated from the “accepts” by a series of oscillating and vibrating screens. Accepts, which measure 1/4 in. by 1/4 in. by 1 in., are then sent through a series of three overhead magnets and four head-pulling magnets, which remove metal objects from the wood.
The chips are then taken by conveyor to a paddle wheel that keeps them submerged under water. The chips float to the surface and grit, dirt, sand, rocks and other unwanted materials drop out.
“We’ve got two cleaning systems and we’re adding two more,” says Tavoda. “We’ve got magnets and screens and a wash system, and we are going to add a chip-cleaning system and an eddy current. Most plants have magnets to help clean up the stuff or a washing system. Then again, nobody else uses 100% urban waste either.”
Carl agrees with Tavoda’s assessment that CanFibre’s meticulous chip cleaning is one of the things that makes the company unique. He also points out that the wood is “already nicely separated” by the time it reaches the plant.
“The supply we use is not a bunch of garbage and banana peels, it’s pretty good looking wood,” Carl says. “But there is a lot of metal and other stuff in there and we do a huge amount of work to get all that out. We do so much work that we feel we end up with a cleaner fiber than most MDF mills who use virgin wood.”
The Steam Press
“Urban wood is mixed species, which makes it very difficult for a conventional UF resin to perform consistently,” Tinker explains. “With the use of phenol-based resins we are able to use the mixed species, but the phenol needs high temperature to cure.”
CanFibre uses a patented steam press process that is able to achieve the high temperatures necessary to cure the resin.
“The steam injection allows the company to get a very quick cure and a very short press time,” Tinker adds. “While a standard MDF plant may have a cycle time of six to seven minutes, we are able to cure the panels in four.”
The phenol resin and steam-injection press have some other benefits, according to Carl. As a result of the high amount of energy used in the press, the MDF a high quality of fiber that is the same density throughout, he says.
“Most MDF gets over-cured at the outer edges and tends to be quite soft in the center,” Carl says. “The fact that AllGreen is just as hard in the center as it is on the surface means that paint adheres more evenly and tool wear is improved.”
Carl also says that the phenol-based resin improves moisture-resistance levels.
A second plant is currently under construction in Lackawanna, NY, and is scheduled to be up and running in the spring of 2000. CanFibre has also obtained permits to build its first European operation, which will be located in Amsterdam, near European furniture manufacturers.
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