Ultraviolet coatings today are being qualified and implemented in a variety of industries and applications. The true benefit to implementing UV is bona fide economic savings and return on investment (ROI). Understanding these true costs of each area is critical to your ROI and, with UV, you get one better—return on the environment (ROI+E). This is described as faster, smaller, and cleaner.
Faster: Line speed, coating cure, and coating optimization.
Smaller: Floor space, work-in process, energy consumption, maintenance costs, capital equipment cost, and quality costs.
Cleaner: Zero VOCs/no HAPs/NVPs, reduced reporting, and improved health and safety. Following are some sample customer applications for UV coating on metal substrates (see Figs. 1–5).
The main question: Does the project have an acceptable economic ROI? In order to best answer this question, a detailed economic analysis needs to completed. The following analysis was conducted on conversion from 35% solvent-based liquid coating to UV 100% solids-based liquid coating. The application illustrated entails a black UV coating on a hydraulic cylinder (see Fig. 6 and Table 1).
Table 1: Black UV Coating on Hydraulic Cylinder| Substrate | Metal |
| Application | Rotary bell atomizer |
| Technical | High temperature will cause cylinder failure |
| Economics | Elimination of IR oven; elimination of work-in-progress; improved quality and less waste; and ability to reclaim and reuse coating |
Economic Review and Analysis
Faster Production Capabilities
Currently, the solvent-based production line speed is maximized at 10 feet per minute, limited mainly due to the size of the customer’s existing thermal oven system (see Table 2). With a well-designed UV-based coating system, 15 feet per minute can be attained, which equates to a net increase in production of 50%.
Table 2: Comparison of Production Capabilities | Parts | 18-inch centers |
| Current line speed | 10 ft/min
(6.6 parts/min) |
| UV coating line speed | 15 ft/min
(10 parts/min) |
| Additional parts/min | 3.4 |
| Minutes per shift | 480 |
| Two shifts | 2 × 480 ×3.4 parts = 3,264 parts per 2-shift period |
| 220 production days | 220 × 3,264 parts = 718,080 additional production units possible |
Faster Coating Cure
In the near future, the hydraulic cylinder will be redesigned with a new seal that will not tolerate any heat exposure. A customer’s existing thermal system exposes the hydraulic cylinder to 400°F for six minutes, which would cause irreparable damage to the part. The UV system would protect the part against excessive heat exposure, with maximum heat exposure being around 120°F. This is mainly due to the fact that the UV curing system will cure/dry the paint in under two seconds.
Faster Coating, Faster Coating Optimization (100% solids vs. 35% solids solvent)
A customer is currently purchasing a solvent-based formulation at 35% solids for $27 per gallon. The new UV coating is 100% solids and is priced at $75 per gallon. Comparing apples-to-apples: for 35% solids solvent, coverage equals 1,604 ft2 at 1 mil × 0.35 = 561.4 ft2. So, one gallon of solvent-based coating gives you 561.4 ft2 of coverage at 1 mil. To equal 100% solids UV coating coverage of 1,604 ft2 at 1 mil: coverage at 1 mil: 1,604 ft2/561.4 = 2.857—meaning you would need 2.857 gallons of 35% solids solvent to equal one gallon of 100% solids UV coating.
Real Cost of Coverage (1,604 ft2 at 1 mil)
Real cost of solvent-based coating: 2.857 gallons × $24 = $77.14. UV 100% solids coating: $75 per gallon. Overall, UV 100% solids coating has a lower cost per gallon by $2.14.
Faster Coating Optimization (reclaim)
Solvent-based coating technology does not allow for reclaiming any coating that is not applied directly to the part. UV is different; you can reclaim 100% solids UV coatings and reintroduce them back into the system after filtering. Reclaiming 100% solids UV coatings allows the spray system to achieve an efficiency of 95% overall (see Table 3). For this application, it allows the customer to reclaim an estimated six gallons per shift.
Table 3: Efficiency of Reclamation| Two shifts | 2 × 6 gal × $75/gal = $900 per 2-shift period |
| 220 production days | 220 × $900 = $198,000 paint coating savings |
Only 100% solids UV coatings can offer this additional benefit of reclaiming coating and reaching an efficiency of 95% (see Fig. 7)
Smaller Floor Space Requirements
The UV system will provide a much smaller footprint on the manufacturing floor. The UV footprint is 550 ft2 versus a thermal oven footprint of 2,300 ft2. The UV-based coating system offers 72% less physical floor space versus the solvent-based coating system. This represents a significant cost savings for the customer.
Smaller Work-in-process
The work-in-process has associated costs because it ties up capital. The larger your work-in-process inventory, the larger your quality risk. The UV process basically eliminates your coating WIP. With the implementation of UV, the customer will reduce WIP by an estimated 450 units.
Less Energy Consumption
The UV process offers the opportunity to reduce energy consumption by a great margin (see Table 4). In the example provided in Figure 9, the UV system provides the customer in excess of $27,000 in annual savings.
Table 4: Energy Savings with UV Process| Current electrical and gas costs per hour | $10.78 |
| UV light/equipment electrical costs per hour | $3.07 |
| Overall cost savings per hour | $7.71 |
220 production days
(2 shifts at 8 hours each) | $27,139 in annual energy savings |
Less Capital, Smaller Capital Equipment Costs
UV systems typically cost less than oven-based curing technology and typically require shorter conveyors, less material handling, and fewer mechanics overall. In the case of this customer, the thermal oven system was purchased several years ago. The new UV curing system must be utilized due to a redesigned part.
Smaller Quality Costs
With UV technology, quality problems are immediately noticed and addressed. With the current thermal coating system, you must wait until the product has been fully dried. Once you find a problem, you have a thermal oven full of scrap product, which dramatically increases your product scrap costs.
Cleaner: Zero VOCs, no HAPs, and no NVPs.
One-hundred percent solids UV systems typically have zero VOCs, no HAPs and no N-vinyl pyrrolidones (NVPs). Solvent coating systems typically contain a variety of these pollutants and need to be specifically managed on site at the customer’s location.
Reduced Reporting
Solvent systems typically require specific internal controls. One-hundred percent solids UV offers the benefit of eliminating any VOCs and the associated reporting that can be required by local and state regulatory authorities. Elimination of any VOC scrubbers will also provide significant cost savings.
Improved Health and Safety
With 100% solids UV systems, the customer can eliminate health and safety issues typically associated with solvent-borne coating systems. However, sound safety practices still need to be followed when using UV coatings. Again, this can be assessed by measuring worker time away from work, compensation claims, and external environmental impacts.
It is critical that a complete cost analysis is completed before any coating technology is selected. UV coating technology offers a great deal of advantages that typically will show return on investment for your application, plus provide excellent environmental benefits.
About the Authors
David Hagood is president of Finishing Technology Solutions, LLC (Vermilion, Ohio), a finishing consulting and systems integration company specializing in the design and integration of automated UV-curable coating and curing systems. He has been involved in the finishing industry for nearly 30 years and has worked for companies that manufacture finishing application equipment and UV cure equipment. With those companies, he focused on design and sales of automated, engineered finishing systems.
Michael Kelly is president and CEO of Allied PhotoChemical, Inc., Kimball, Mich. He has held a variety of management positions, such as managing director Europe/Middle East/Africa; president/Italia Operations for Wonderware Corp.; and sales manager at McNaughton-McKay Electric. Kelly received a masters of finance degree from Walsh College, a masters in management from Central Michigan University, and holds a bachelor of science degree in industrial engineering from Iowa State University.