Wood dust -- It’s a fact of life. Likewise, dealing with it is a fact of life. In the home it’s a simple, quick task to get done. In the shop, that's a different story -- while it might be worth a laugh to see a maid running from the panel saw to the belt sander, feather duster in hand, it wouldn't be very effective.

So, once the humor of the futility of the feather duster has subsided, what to do? Some let the dust pile up, some try to keep it in check with brooms and shovels. Depending on the size of the operation, one viable option is installing a dust collection system.

Dust collectors are available as single units that attach directly to individual machines, or central systems that, when properly configured, provide coverage for all the machines in the shop.

A dust collection system consists of a collection hood, ductwork, run, rotary airlock or slide gate, primary collector, and secondary collector. On most wood applications the dust collector will serve as both the primary and secondary collector.

Some, although recognizing a dust problem, are hesitant to invest in dust collection because the return isn't immediately apparent. But that doesn't mean it's not a good investment. There are numerous advantages to dust collection.

1. Health

Why buy dust collection? In a word: Lungs.

"Airborne particles will cause lung and throat cancer somewhere down the road if they don't eliminate that stuff," stresses Rosemarie Kraemer, vice president, Kraemer Tool & Manufacturing Co. Ltd.

Bryan Murphy, president, Dust Technology, Inc., echoes the sentiment: "Numerous medical studies have deemed dust a major respiratory hazard. Aside from the ever-looming possibility of lung cancer, many woodworkers are haunted by nagging side effects such as continuous coughing and sneezing attacks, throat phlegm, asthma, and eye irritation."

Curt Corum, sales manager at Air Handling Systems, points out that the health dangers from dust don't cease when the saw is stopped and the chips stop flying. Fine wood dust can stay suspended in the air for hours.

If the immediate and long- term well-being of employees doesn't strike a goodwill chord of concern, the monetary obligations of failed health might be a stronger influence. Negligence can lead to workers compensation claims and even lawsuits.

2. Legal obligations

Beyond workers compensation, other legal ramifications exist as well. "OSHA gets in on it now," explains Ray Wakefield, president, Aget Manufacturing Co. "You have to follow the rules, and that includes dust collection."

It doesn't just stop at OSHA, though. A host of local and national agencies all flex their muscle to some degree regarding keeping shops dust free. "OSHA will come after you, the fire marshall will come after you, and the Labor Department and the Department of the Environment will come after you if you don't have proper dust collection systems in place," says Kraemer.

3. Insurance rates

Not every basis for dust collection involves the threat of negative repercussions. Larry G. Stevenson, national sales manager, Pneumafil Corp., credits installation of dust collectors with lowering insurance rates.

Richard Bass, vice president of Rudolf Bass, says that when insurance companies rate a shop, they are concerned with maintaining safety and preventing fires. Shops that are clean are less susceptible to such hazards, which can lower insurance premiums.

4. Fire hazards

One of the biggest concerns for insurance companies, not to mention shop owners, is the threat of fire.

"Fine dusts are a fire safety concern," comments Jim Kohl, product manager, Torit Products. "Controlling this dust will reduce the risk of fire."

In central dust collector systems, sparks created during machining can travel through the duct work with the dust. A spark detection system extinguishes the spark, via water or some other medium, thus preventing fires. However, even without spark detection, a dust collector can at least minimize fire damage.

Murphy recounts that a customer was using a router when it hit a piece of metal, causing a spark. The spark traveled through the dust collector and into the storage bag off to the side of the shop. The resulting fire triggered a sprinkler nozzle in that isolated section of the building, which extinguished the fire. "Had that not happened," he notes, "the fire might have engaged a sprinkler over the brand new $200,000 router and destroyed it. Instead, it localized the fire to one segregated section of the shop."

The risks don't end with fires, though. Dust suspended in the air also is combustible. While a fire will severely damage a plant, an explosion can destroy it. In his September 1996 FDM article, "How to Prevent Dust Fires," Thomas Frank, chief engineer in the Seattle district office of Factory Mutual Engineering, spells out the recipe for tragedy. All you need is layers of combustible dust, add something as commonplace as a process-initiated spark, and an explosion can occur.

The offshoot of the first explosion will not only rupture expensive equipment, but the pressure wave created will stir more dust into the air. Airborne dust is surrounded by oxygen, the very fuel it needs for combustion. With new fuel abound, a chain reaction of explosions will result. The sec- ond explosion will probably collapse the walls of the facility.

Research conducted by Factory Mutual shows that a particle size of 0.02 inches (500 microns) or less is all it takes for an explosion.

Torit's Kohl notes that the rising popularity of MDF is added reason for adequate dust collection. MDF creates a finer dust than traditional wood materials.

5. Finishing quality

An abundance of dust in the shop also can create problems in the finishing department. A high concentration of wood dust in the air can be drawn into paint booths, creating a defective finish on the product, explains Corum. That either results in rework -- and lost production time -- or lower product quality.

6. Positive image

Clearly your work serves as an indicator of your quality to clients, but so does the atmosphere that work is created in.

Plain and simple, customers like to visit the shop and they will feel your products are better made if you have a clean shop, Kraemer says. However, if they come in and see a sloppy operation, it reflects on the product's image.

"They think if you're sloppy in keeping the shop, you also won’t be too fussy with the product you're selling," she concludes.

"A dirty shop doesn't make money," states Dustvent president Arthur Rosenquest. "You walk into a dirty shop and it isn't only that the shop is dirty -- there are other things wrong in that place. It may be a barometer of what's below, behind, or beneath the surface. The dirtiness on the surface is just the indicator."

7. Employee morale

Beyond the impression a dirty shop gives to customers, it also sends a message to the workers. "Housekeeping is a main item," says Wakefield. "If the area is clean and there are better working conditions, people are happier and more productive."

Joe Hill, president of Joe Hill Co., Inc., says, "I've been in a lot of plants that are really dirty. You know, they're stepping over big piles of sawdust. And those plants tend to have a big turnover with employees."

8. Increased production

Tom Miller, project manager, W.C. Wiedenmann & Son, Inc., explains the hardest part about selling a dust collection system can be that shops typically don't want to allot any portion of their capital budget to something that isn’t revenue-building, at least not in a measurable format. However, he points out that a clean working atmosphere does increase worker productivity.

Ever tried working or driving in the middle of a blizzard, unable to see what's in front of you? That’s how Corum describes working in an environment without dust collection. With vision impaired by clouds of sawdust, making accurate cuts, measurements, or assemblies is difficult and dangerous.

"Uncontrolled dust settles onto workers’ safety glasses," Kohl says. "With effective dust control, workers stop to clean their safety glasses and work areas less often. By reducing the amount of dust in the working environment, workers are free to spend more of their time producing more, higher-quality parts."

9. Equipment maintenance

A key to improved production, beyond the workers themselves, is the machines they are working on. And machines’ performance and longevity are hindered by dust.

"A lot of machinery tends to operate better if the dust is getting carried out of the machine," says Andy Cowan, vice president, Rees-Memphis, Inc. "It just tends to make a longer life for the machine and the tooling. If waste gets left in a machine, that has an effect on the cut."

"Minimizing wood dust through the use of dust collection devices reduces maintenance expenses," adds Kohl. "Bearings and other parts that wear due to the presence of dust must be replaced more often, and to maintain product quality, the equipment must be cleaned often."

Stevenson says that dust collection extends tool life because of the constant removal of wood waste due to a consistent pressure drop across the dust collector. Corum adds that not only does dust collection simply allow cleaner operation of machines, it also prevents defective work. Wood chips laying on boards can create indentations when the material is planed.

10. Custodial cost

Even if a dust collection system isn't in effect, something still has to be done about the sawdust that piles up. As Stevenson points out, up to 60 percent of the raw stock is removed by machining and sanding to obtain a finished product. That adds up to a considerable amount of waste ranging in size from large pieces of wood to submicron particles. And, something has to be done with the waste.

To Otto Seeman of Murphy Rodgers, using a dust collector is the only realistic way to keep a sizable shop at a workable level of cleanliness. "It’s really the only way to get rid of waste unless you sweep it up," he quips. "And, that's kind of ridiculous."

In fact, Cowan sees the issue as a prime selling point for dust collection. As he puts it, anytime there's waste that's generated that you don't have to handle, there's a payback of labor savings.

In the end, it's up to the individual shops to determine if they're generating enough waste to warrant an investment in dust collection, either in portable dust collectors or, if they're generating enough waste, a central system.

However, it's better to make the determination and act on it than to wait to see what happens. As Frank notes, "Smart management doesn't wait for losses to happen, but instead works at strategies that are tailored to the unique needs of a facility."

Buy Right, Buy Smart

You realize your shop is finally at a point where you need to install some form of dust collection. What's the next step?

According to Riccardo Azzoni, Atlantic Machinery Corp., most people investigate dust collectors asking the wrong questions, such as "What's the unit's horsepower?" or "I need a three-bag unit."

"It would be like buying a car based on the number of cylinders, so you get a sports car with two seats, but you have four kids," muses Azzoni. The key, he says, is the cfm requirement.

"If the customer knows the cfm rating that he needs, then he should ask for a dust collector with that cfm," says Azzoni. If you don't know your cfm requirement, you need to provide enough information as to the size of the space, the number of machines that will be served by the unit, the size of the inlets, and how many machines will be running at any given time. From this, the manufacturer should be able to calculate the cfm requirement.

Calculating the cfm requirement for a shop is a basic process. Every woodworking machine that is sold comes from the factory with a cfm requirement. "All you do is add up the cfm requirement for the number of machines that you have and you come up with the overall cfm requirement. It's a cumulative figure," explains Azzoni.

But it's not quite that simple. You also have to make deductions for static pressure. For example, if a shop's overall cfm requirement for all of its machines amounts to 10,000 cfm, and the static pressure "deduction" is 3,000, the company needs to purchase a 13,000 cfm unit to get the 10,000 cfm they require. And, of course, that's a minimum figure. In the case of central systems, it's recommended that customers buy more cfm than is currently needed to accommodate any possible future machinery purchases.

Azzoni says some companies don't account for future expansion, and some don't even buy the minimum they need at the time of purchase. Azzoni says some shops determine their dust collection requirement, and then figure they can get by with maybe 70 percent of that.

"If the machine is designed for a certain cfm requirement and you don't provide it, then some of that dust will stay in that machine. It will affect the accuracy, the workings, and the electrical system of the machine," he warns.

Three Reasons to Invest in Spark Detection

"Spark detection systems have proven to be a very important defense to the fire and explosions that can occur from everyday processes," explains Allen Wagoner, Flamex, Inc. Such systems are generally approved by the professional loss control community as a sensible means to combat fires and prevent the potential for explosions.

There are three primary reasons to consider adding a spark detection system to a central dust collector: safety, lower insurance rates, and legal regulations.

Marshall Lloyd, GreCon, explains that when a spark occurs in a shop that has a central dust collection system, the dust system will transport it right along with the dust the machine generates. "The system will do what it's supposed to do," he explains. "It will evacuate those hazards right into the filter."

Without a prevention system in place, the filter is in jeopardy. With spark detection, the ember is extinguished and fire, explosion, and costly facility and mechanical damage is prevented, as is employee injury. "The main objective is to protect that filter," cites Lloyd. "That's where the money is."

Car owners with antilock brakes, airbags, and car alarms receive discounts to their automotive insurance premiums. Likewise, Lloyd points out that shops equipped with spark detection devices receive favorable insurance rates.

Scott Rowsell, Hansentek, also acknowledges that guidelines for the prevention of fires in dust collector systems is within the jurisdiction of various levels of local authorities and municipalities. Lloyd points to the National Fire Protection Code, NFPA 664. "Basically," he says, "that code recommends the use of spark detection, particularly in applications where you are returning the air back into the building." In some areas the NFPA code has been adopted as law, in other cases it serves as a recommendation.

Of course having a system doesn't help if it isn't maintained properly. NFPA 69 requires that spark detection systems that are in operation be maintained on a weekly basis, while sections of NFPA 72E and 664 outline recommendations and test procedures for proper maintenance.


©1997 Reed Elsevier Business

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