W&WP March 2003
Industry Makes Strides in Dust Collection Efficiency
Wood products factories are cleaner than ever on balance, but there is always room for improvement.
By Jo-Ann Kaiser
Implementing and maintaining an efficient dust collection system is important for a variety of reasons ranging from finished product quality through plant safety.
During the early 1990s, woodworking companies momentarily faced the added challenge of complying with an air quality standard implemented by the Occupational Safety and Health Administration geared toward protecting woodworkers from wood dust's perceived harmful effects. The standard, which was soon overturned by the Appellate Court, had required companies to limit emissions of wood dust to 5 milligrams per cubic meter for hardwoods and softwoods, with a separate standard of 2.5mg3 set for western red cedar.
Wood dust is back in the headlines because of a December 2002 decision by the National Toxicology Program to list it as a "known human carcinogen." Because OSHA nominated the listing, there is strong reason to believe that it is just a matter of time before the government workplace agency renews its efforts to create a national wood dust standard.
According to a handful of dust collection representatives interviewed by Wood & Wood Products, the woodworking industry as a whole made big improvements to its dust collection systems throughout the 1990s. Yet, there remain companies that lag behind the movement, including those that add new equipment without giving adequate consideration to upgrading their dust collection abilities.
The 1990s: A Decade of Progress
Jeffrey Hill, general manager for Oneida Air Systems Inc. of Syracuse, NY, says the 1990s represented a time of progress. "We dealt with two main types of customers in that time period - those who never had central dust collection and got started with it and those who had inadequate dust collection and replaced what they had with a properly designed system. For either of these customers the progress was great and they are now enjoying the many advantages that good dust collection brings to their organizations."
Mike Althouse, industry manager for Mac Equipment of Sabetha, KS, says he sees dust collection being applied to more processes than in the past. "We also see a big shift to the use of fabric filtration rather than cyclones. I think fabric filtration is more effective and emits less particulate into the atmosphere."
In addition to the development of more efficient filter media, Althouse says improvements have been made in ductwork and hood designs. "The machines that create the dust are better designed to capture the dust they create."
Riccardo Azzoni, president of Atlantic Machinery Corp. of New Milford, CT, also talks about progress he has witnessed since the '90s. He adds that much more improvement is warranted. "There are still a lot of companies - mostly small to medium sized - with inadequate dust collection in their plants. I attribute that to two factors. Some people have a hard time spending money on a non-revenue producing expense. In their minds dust collection doesn't give them a return on investment the way a machine that improves production or provides a better finish will."
Azzoni says the second factor is that some woodworkers are confused about how to go about tailoring the ideal dust collection system for their needs. "They don't always know which questions to ask to solve their problems. Typically they ask for a dust collector by number of bags or horsepower without knowing if it applies to their facility."
Azzoni said he determines the type of dust collection system a particular wood products manufacturer needs by asking a variety of question, beginning with how many machines it has and how many machines it will have running at any one given time.
"If people have 10 machines, they seldom have all of them running at once. It doesn't take as big of a dust collector to run six or seven machines as it will to run 10 and this is an area where people can save money," Azzoni says. "I also ask questions about the size of the dust hoods on the machines and the distances between the machines and dust collectors so we can figure out the static pressure. This helps tell us what size horsepower motor to put on the dust collector to be efficient.
"By getting our customers to answer these types of questions, we can eventually get the information we need to design a dust collection system that will best suit its operation," he adds.
Petra Meinke, senior marketing product manager for Donaldson Torit of Minneapolis, MN, says that during the 1990s, an increasingly large number of wood products manufacturers bought dust collectors.
"This is the actual improvement," Meinke says. "In addition, there is much higher emphasis on optimal hood design to better capture wood dust and on proper ductwork design. Collector, filters, hoods and ductwork must be engineered together for optimum results."
Curt Corum, sales manager for Air Handling Systems of Woodbridge, CT, credits companies' willingness to protect their employees' health for the substantial progress in dust control. In addition, Corum says, customers who have purchased automated equipment, such as CNC routers, large moulders and double-end tenoners, have had to adjust dust collection material for the new machinery.
"We are seeing sophisticated machinery being installed in small shops with two to three people," Corum says. "The new machinery has led dust collection manufacturers to do the best job possible."
Otto Seeman, president of Murphy-Rodgers Inc., of Huntington Park, CA, also notes the impact of technology on dust collection requirements.
"We've seen woodworking shops installing larger, high-speed CNC machinery over the past decade," Seeman says. "These machines create an enormous amount of airborne dust. These new high-speed machines can also trap the dust and waste particles internally, which can damage the machinery if the dust and materials are not exhausted and collected properly. In the '90s shops became more aware of the need for efficient dust collection systems that matched the speed and efficiency of the new CNC equipment so we added new products that fit our customers' needs."
Among the products developed by Murphy-Rogers and other dust collection specialists were cost-effective external and internal air cleaning systems that fit into small spaces, including shops with low ceilings. Dust collectors that recirculated heated air back into the building were also developed in response to increases in energy and heating costs, Seeman says.
"We heard from our customers that labor costs were a problem and we created machinery that required less maintenance," he adds.
'A Time of Learning'
"People had to revise to keep pace with the sophisticated machinery," Kraemer says. "They needed more speed and cleaner air exhaustion and they needed to be sure to tailor the system to their plant. If they were running 24 hours a day, they couldn't expect a system designed for a nine- to 10-hour workday to fit their needs. They (wood manufacturers) learned a lot and so did we."
Ray Wakefield, president of Aget Mfg. of Adrian, MI, describes his company as a niche supplier.
"We supply to small companies and school woodshops. There's been quite a change in this area too, mainly because the schools had removed woodshops from the curriculum for a while in favor of things like computer education. We are seeing a big return to tech classes in high school in addition to computer training. Schools and small shops have learned they needed to spend money to do the job correctly," Wakefield says.
Noise a Factor to Some
"First of all, high-quality internal return self-contained dust collectors became more readily available at increasingly competitive prices, thus allowing our customers to purchase efficient, well-made dust collectors that could be installed in the woodworking shop," Hafey says. "They generate high CFM capacity, are space efficient and have enough board storage capacity to be a useful and justifiable purchase."
Hafey adds that the issue of decibel levels created by unitary dust collectors and neighbors' sensitivity to central collectors' noise have become serious concerns to wood products companies, especially for those in the small to mid-range.
"Noise has become a major issue in today's urban woodworking environment. The technology to lower noise is now available and is being sought after by companies whose dust collectors are located near machine operators and woodworkers." Hafey adds that despite the fact that quieter dust collection systems cost more, they represent about half of her company's sales.
'Known Human Carcinogen'
"The addition of wood dust to the listing certainly will motivate companies towards better dust collection," Hill says. "Any time a reputable third-party can provide concrete information that shows people they are endangering their health, you will get some results. With this and other recent health studies, consumers are realizing that wood dust is more than just a nuisance that needs to be cleaned up. We have already observed a response with customers asking how they can help minimize their employees' risk of exposure."
The National Toxicology Program's decision could lead wood products companies to take a closer look at the efficiency of their systems, especially in terms of controlling fine dust particulates, Hafey says.
Azzoni adds that it will motivate companies to upgrade their systems to more adequately address the efficiency of their dust collection systems. "It will put pressure on the owners of companies from within the company itself When employees read about it they will request that their work environment is improved. I think this type of clear ruling will make a big change in peoples' attitudes," he says.
Meinke says the biggest impact of the NTP ruling is that it will help educate the industry about the associated risks of breathing wood dust.
"We can only hope this type of education will motivate more companies to reduce dust emissions in the future. What we are currently seeing in the woodworking industry somewhat deviates from this thought process. While many of our customers make worker safety their number one priority, the reduction of dust emissions in woodworking plants is to a larger degree driven by the increasing sophistication and computerization of woodworking tools," Meinke adds.
Corum says the good thing about the ruling is that it will "open people's eyes to the fact that wood dust poses a serious threat. Dealing with wood dust properly is no longer going to be an optional thing."
According to Althouse, most companies are serious about addressing the health and safety concerns of their employees. "If a company is exhausting air outdoors, this situation is probably not as important as if they are returning filtered air to the manufacturing area. The higher efficiencies of filtration systems and sophisticated monitoring systems are also better because they let manufacturers know immediately if they have a problem so they can fix it."
Kraemer says addressing this problem is a great way for an employer to show he cares for his employees. "We have known about the dangers of wood dust for a long time. It's very encouraging that the problem has been formally addressed. This is good for the industry," she says.
Room for Improvement
"Major improvements have been made in the area of dust collection, but a lot of little, sometimes minor changes can be made that will add up to significant improvements," Althouse says. "Some filtration media can reduce outlet emissions by up to four times versus the standard polyester bag. This is fairly easy to do. Switching to the more efficient media in the equipment can result in efficiencies increasing from 99.9 percent to 99.999 percent with a fairly modest investment in capital."
Hill says he thinks woodworking companies need to "take a more proactive approach to dust collection. For too many companies, dust collection is an afterthought. "The more aggressive equipment making its way into small woodworking shops needs more attention paid to dust collection so that dust exposure is minimized."
Speaking particularly about smaller shops, Hafey says, "Areas to be addressed include supplying appropriate CFM suction capacity to equipment collecting dust from all machines in the woodworking shop and reducing decibel levels to the mid to low 70s. Also, companies need to reduce airborne particles to a minimum safe level for a healthy, clean dust-free woodworking environment."
Corum frequently encounters two scenarios that could stand improvement. "Conventional dust collection for woodworking machinery like table saws and planers feature round outlet collars and hooks with pipes that bring the dust to the dust collector.
"Another area has the high velocity vacuum hooked to a dozen or 16 machines and the dust collector. A plant can have a nice elaborate system for their sophisticated machinery, but still leave a serious void with hand held or bench-top machines with small orifices. The two don't overlap. If you try to fit hand-held equipment and bench top equipment to hook to a system designed for the large machine, it's like trying to drink a milkshake with a cocktail straw. I tell people they have to take a second or third step to get the job of dust collection done correctly.
"After they address the two different types of machinery, adding conventional collection plus high velocity vacuums, I also like to see them install ceiling suspended air cleaners," Corum continues.
Plants also need to pay attention to the types of filters they uses. "Better filters make the difference. Some of the machinery emits such fine dust that if the filter isn't designed to catch it, you return 2 to 3 percent of the dust back into the air," Corum adds.
According to Kraemer, most large companies are addressing dust collection issues, but she sees a need for improvement in smaller shops - those with less than 20 employees, where money may be an issue.
"Even if money is tight, this is not an area to shortchange efforts," Kraemer says. "I see problems with shops not having enough filter area. Sanders especially need more filter area. It's critical to have the right filter area for the kind and amount of dust you produce. To begin with, shop owners have to be honest about all the various machinery they have. Dust collection systems can't do the job when shop owners underreport the number of machines and types of machines running. We stress good communication here between the designer of a system and the owner of the shop."
Azzoni says the use of cartridge filters can help in the collection of fine dust. "This is still a big problem area. A normal bag is rated for 3 to 7 microns, meaning that smaller dust gets blown through the bag but cartridge filters have a much tighter grid and the filtration can be as much as 10 times better than a standard bag. There was a lot of resistance in the beginning to this technology. People didn't want to spend the money for cartridge filters because they didn't see the advantage. But we see that as a growing trend.
"With the bigger, outdoor systems, cartridge filters have been around for a long time but there was nothing available for the mid range or smaller inside dust collectors for people who couldn't go outside," Azzoni adds. "This has proven to be a winning situation to have cartridge filters available because it's the only way to capture the very fine dust efficiently."
Azzoni adds that fine dust particulates generated from things like sanding, CNC routers and solid surface fabrication represent areas that need the most improvement. He thinks that cartridge filters can do an excellent job in controlling dust in these areas.
Meinke sees the need for at least three areas of improvement. "We need to continue to improve worker health and safety because wood dust has been linked to cancer of the nasal cavity, lungs, gastrointestinal tract, and Hodgkin's disease as well as to bronchitis, asthma, and emphysema. This, unfortunately, is not just a matter of telling shop owners to install the proper dust collection equipment, it also requires a cultural change, a break of habits, if you will, for many woodworkers themselves. Continued education of the risks is key to success here.
"Also, we need to better protect today's more sophisticated woodworking equipment," Meinke says. "Computerized tools don't work well in dusty environments and can negatively impact productivity and profits. There is a perception that dust collection equipment is expensive, but operating a woodworking plant without it can be devastating to the bottom line in more than one way."
Meinke concludes that the wood products industry is beginning to use many other materials besides wood and this includes composites, resins, plastics, laminates, and solid surface materials to name a few.
"These types of materials generate much smaller, finer particulates which further supports the need for making a safe workplace and protecting the machinery. The new materials and manufacturing techniques also require more sophisticated dust collection technology. It is critical that we continue to educate the industry of its many risks," Meinke adds.
Seeman says he knows of many companies who have invested thousands of dollars in new woodworking equipment but their production line broke down because wood particles and excessive dust clogged their machinery, causing internal damage. "This happened because the shops neglected to spend a little more on an efficient dust collection system that would have protected their machines." He says he hopes to improve manufacturing by convincing his customers to select the right system for their operations.
Wakefield adds that the most important hurdle in dust collection is convincing a client to "do the job right." "It's going to cost more to do things right, but it's very worth the money," he says.
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