Film Converter Switches from Arc to Fusion UV Curing Equipment
Significantly Improves Reliability and Slashes Maintenance Costs
Dunmore Corporation (Bristol, PA) is a global manufacturer of metallized, coated, and laminated films. Their products include high performance and durable print media, security films and tapes, plus many specialized engineered films for a wide variety of applications such as aerospace, renewable energy, graphics and surfacing films. They operate three 9001:2000 ISO Certified manufacturing facilities, two in the US and one in Germany. Since Dunmore runs a variety of different products, each line typically has both thermal and UV curing capabilities. Some 15 years ago Dunmore retrofitted the UV curing onto their existing thermal lines to produce high performance scratch resistant coatings with lower solvent emissions.
At the Bristol, PA plant a 74-inch wide production line had a ten-year old arc lamp system that over the years was requiring more and more maintenance. “It got to the point where major repairs were needed before each production run,” commented Paul Sullivan, Director of Engineering. So the decision was made in 2007 to replace the UV curing equipment. Another line in the plant has two rows of Fusion UV F300S curing systems that have been operating on the line for fifteen years. Based on Dunmore’s experience with this system and its reliability, they decided to consider Fusion UV equipment to replace the old arc lamp system.
A major concern was heat management because the polyester films running on this production line can easily deform if exposed to temperatures above 150°F. The existing arc lamp system had a complicated arrangement of water-cooled reflectors and shutters, a secondary dichroic reflector and a chill bed in an effort to reduce substrate temperatures.
To make sure the Fusion UV system could cure the coating while maintaining low substrate temperatures, Dunmore used a F600S system with dichroic reflectors from Fusion UV’s stock of demonstration equipment and ran trials on their pilot coating line. Dunmore was able to make comparisons between the two-row F300S system they had and the F600S by taking radiometry and temperature measurements. The testing proved that the coating could be cured with no heat distortion of the polyester film substrate using one row of F600S systems.
Following the pilot coater testing, Dunmore worked closely with Fusion UV’s Custom Engineering group to specify the UV curing system for the existing line. The new system has one row of VPS/I600 UV curing systems mounted in an MLS light shield, with dichroic reflectors and H bulbs, plus a chill bed. The variable power was chosen to allow reduced UV power at slower line speeds. The line typically runs at 100 to 300 feet/minute with one limiting factor being the application of the UV coating. So the variable power capability provides more flexibility in operations.
The new Fusion UV equipment was installed in November of 2007. Because the old arc lamp system failed dramatically just prior to receiving shipment of the Fusion UV equipment, the decision was made to completely remove the old equipment instead of leaving it as a back-up to the new. The single row of Fusion UV lamps took up about half the space the two-row arc lamp system had.
The arc lamp system failure also put added pressure on getting the new system operational as production orders needed to be run. Dunmore installed everything themselves except for the cooling air ductwork and blowers. It turned out this was a fortunate decision given the tight timeframe to get the system up and running. Fusion UV assisted with start-up and training of the operators and maintenance employees at Dunmore. Then Dunmore requalified production parameters with the Fusion UV equipment and started running production in December.
When asked if he is seeing the maintenance savings he expected, Paul says, “Definitely yes. The arc lamp system was a custom, one-off design that simply wasn’t well designed mechanically.” Because the arc lamp system used water, in addition to air, to cool the shutter and lamp, this meant water could leak above the substrate and even into the electronics of the UV system itself, which it did on occasion causing major problems. The Fusion UV system uses only air to cool the lamps while the chill bed located below the substrate is cooled with water.
Maintenance personnel have also seen that they don’t have to clean bulbs and reflectors so often. The old arc lamp system pulled air up into the shutter, bulb, and reflector. This caused dirt and coating material to deposit onto the lamp components. Paul says they had a regular cleaning schedule in place. But with the Fusion UV system cooling air is pushed down through the lamps so less dirt deposits onto the bulb and reflector, and there is no shutter needed since the lamps can turn on and off so quickly. This has significantly reduced the lamp cleaning intervals.
Paul commented, “The Fusion UV systems are running great with no heat issues and Fusion has been very responsive to our needs. We sent our maintenance employees to Fusion’s one-day maintenance and troubleshooting course. In addition, after running the line for a few months, we decided to change how the system is controlled. Following discussions with Fusion UV’s engineers, we decided a software change would allow us to automate the operation of the UV curing equipment, simplifying the operator’s job.”
For more information about Dunmore visit www.dunmore.com.