Critical Considerations for Clean Room ConveyorsTuesday, September 13, 2011
What to look for – and avoid – in specifying a conveyor for your clean room
Selecting and installing a conveyor system in your clean room can dramatically improve your productivity. Therefore, understanding your needs and recognizing the attributes of the conveyor systems you are considering is imperative.
When analyzing a clean room conveyor solution, you should consider initial cost, total cost of ownership, maintenance needs, noise levels, energy consumption, flexibility and clean room classification.
Total Cost of Ownership
An important step in evaluating the purchase of a clean room conveyor system is determining the total cost of ownership. A total cost of ownership investigation takes the purchase beyond the initial capital investment and installation. Questions to be considered during the investigation should include: How will energy costs affect the long-term return on investment? What are the preventative maintenance requirements? How often and at what cost will the belt need to be replaced? What is the expected lifespan of the equipment?
Answering these questions will help you evaluate the best conveyor choice for the long-term.
Initial cost of the conveyor may or may not be indicated by the clean room classification rating received for the conveyor system. Look for a “standard” conveyor that meets your clean room environment needs with the least or no additional cost to the conveyor. Reconfigurable modular conveyors offer a Federal Standard 209D Class 1 (ISO Class 3) rating at a standard conveyor price.
How flexible is the conveyor in length, configuration and the addition of accessories? In industries where production needs can suddenly change, or where sudden innovation is common, a conveyor with flexibility such as the ability to be reconfigured like Lego® building blocks, helps manufacturers employ rapid and proactive methods to meet the demands of new developments and manufacturing changes. Reconfigurable conveyors offer the flexibility of easily changing length and angle configurations. Modular conveyors also allow for easy adaption of clean room accessories and components such as HEPA filters, tunnel enclosures, ionizers and hermetically sealed entry/exit gates.
Clean Room Classification
The most critical requirement for a conveyor in a clean room environment is, of course, its clean room classification. Conveyors rated to a class 100,000 are readily available, but for processes requiring true contamination control, class 100,000 is well out of range. Indeed, a truly sensitive process will require a vastly stricter specification (down to class 1 in some cases), while other processes in the same facility require only class 100 or 1,000. Your range of clean room requirements should be considered when making your conveyor purchase. Why purchase a class 1,000 conveyor when you can purchase a class 1 conveyor -- for virtually the same price -- that will meet all of your clean room conveying needs? Another aspect of conveyor specification to consider is technological changes that may require an upgrade in the clean environment rating. Therefore, it may be advisable to specify a conveyor with a higher cleanliness class such as a modular conveyor with a Federal Standard 209D Class 1 rating.
Noise can be a contaminant in the clean room. Although maximum permissible exposure limit for noise set by OSHA is 90 dBA, a range of 50 to 60 dBA is actually considered comfortable. There are no conveyors that can be run in complete silence. With all the working and moving parts that most conveyor processes involve, noise is inevitable. But, the level of noise produced by conveyors runs the gamut and can exceed 70 dBA. Therefore, when it comes to noise levels, remember that there are quiet conveyor systems available, such as modular conveyors that operate below 50 dBA.
Maintenance and Upkeep
Another consideration relates to the maintenance and upkeep required by each conveyor system being considered. How often, how easy and what is required to maintain and keep the conveyor clean? Modular conveyors use a FDA approved modular plastic link style belting and brushless DC motors. Plastic link style belting is self-lubricating, requires no maintenance, and is easy to clean and repair. Positive sprocket drive and tracking with the plastic link style belting eliminates slippage and edge damage doing away with the need for belt replacement. Brushless DC motors include maintenance free gearboxes that are grease packed, require no lubrication, and eliminate the potential of leaking oil.
No matter the requirements of the particular conveyor, most conveyor manufacturers use the same large horsepower motor on all of the conveyors they manufacture. Based on each application, modular conveyors utilize the most energy efficient motors, which range from 1/30 HP to 1 HP. Lowering the kilowatts used not only saves money, but reduces the carbon emissions during the making of electricity. Savings can be seen with electric power consumption all day long, year after year. These energy efficient motors are brushless DC motors that meet clean room standards by not emitting carbon like comparable brushed motors.
Taking the time to choose the right conveyor for clean room conveying offers numerous advantages for manufacturers. Modular conveyors provide a clean room classification that meets most requirements, offers increased conveyor flexibility and reduced total cost of ownership at standard conveyor prices.
Jill Batka, President
Dynamic Conveyor Corporation