This article was originally published in ABRN on November 6, 2015 by Andrea Iacucci Ostini.
Two infrared drying technologies—gas catalytic and electric—both offer benefits, challenges to shops
The exciting story of infrared (IR) drying technology for collision repair began more than 3 decades ago in Europe. The North American chapter for the latest IR technology is just beginning. Though IR drying technology has been around since the 1940’s, its modern day version was born in Italy in the late 1980’s at a time when Italian collision repair shops were losing money on nearly every repair.
As they say, necessity is the mother of invention and Italian repair shops needed to drastically eliminate hours from their repair process or they would not survive. So, Italian manufacturers borrowed successful IR drying technology from the paper and printing industry and adapted it for use in collision repair shops. IR reduced the drying time for both the prep and the paint phases of the repair by 75%-90%, which not only allowed Italian repair shops to survive, but begin to thrive.
The first IR curing for collision repair utilized electric technology developed by a Swedish manufacturer. Bellini brought it to the Italian market in 1989. Bellini’s success with electric IR led other equipment manufacturers to work on a gas catalytic option for the collision repair industry. Gas was and continues to be cheaper than electricity in Italy. Also, gas catalytic equipment was already being used extensively for heating, so it was a “quick win” for these companies to develop it for drying auto repairs. With electric IR curing technology winning far greater collision repair shop use in Italy, the gas catalytic manufacturers turned to promoting their IR technology in other countries. The incredible time and cost savings from accelerating the drying process for collision repair helped both electric and gas catalytic IR technology grow throughout Europe.
Use of IR technology has just started growing in North America. Up to now, there has been a lot more written about gas catalytic IR drying systems than electric IR curing systems. Why? Many machines are of Italian design due to the history mentioned earlier and most use gas catalytic as an energy source. However, gas catalytic is not the only IR technology available. Electric IR technology is available and delivers some nice advantages, thanks to careful refinement of its solution over a longer time in-market.
IR Drying Technology Transforming Collision Repair
Let’s start with a review of the overall advantages of IR drying technology, whether gas catalytic or electric. It’s important to note that IR technology will continue to grow in the North American collision repair industry because of its economic advantages. In most cases, repair shops that install the technology realize substantial gains in paint shop throughput due to highly reduced cycle times. The throughput gains, energy cost savings and quality improvements of IR technology are making it a must-have for the highly competitive repair industry.
With IR technology, drying time for both the prep and paint phases of repair can be reduced by hours, which frees up valuable skilled technicians to accomplish additional repairs. Plus, IR energy costs are a fraction of the energy costs to run a conventional system. These savings come from being able to concentrate the drying energy on just the panels needing repair and from the ability of the technology to dry both fillers and coatings much quicker.
With IR technology, there is no need to add expensive accelerators to speed dry time. The exceptionally fast drying time from IR technology allows for high quality results that reduce the need for rework. Additionally, some control systems on the IR units are advanced and precise, yet easy to operate. This also helps reduce rework and increase productivity. Though not inexpensive, the IR drying systems’ investment is quickly paid back due to the increased paint shop throughput and incremental cost saves. In our experience with REVO installations, repair shops have seen paint shop throughput increases up to 80% with paybacks in less than one year.
Production of IR Heat Waves and Cure
As summarized above, both gas catalytic and electric IR systems generate faster cycle times and incremental cost savings, but the two types of equipment generate IR heat differently.
In very simple terms, natural gas powered IR technology relies on the flow of natural gas to a catalytic ceramic plate, where the gas is forced through small holes that break the bonds in the natural gas molecules. Once oxygen is added, the transformed natural gas molecules generate heat. IR heat from the natural gas catalytic reaction is mostly medium wave, with some long wave, as pointed out on the figure below. The wavelength is important to the cure of filler, primer and paint. With medium wave energy, each layer of coating must be cured individually. The waves heat the top layer of the coating to dry it first.
Electric IR technology is generated by sending electrical current to a tungsten filament, which then produces mostly short wave energy. In fact, lab tests done on the REVO product line indicates that 80%of energy emitted is short wave. Electric IR energy has a mix of some medium waves as well. The short wave IR energy from an electric source is able to penetrate multiple layers of coatings to heat the substrate beneath. The heated substrate then helps cure the coating from the inside out. The medium waves help cure the top layer. The mix of waves allow for up to 3 coats to be cured with one pass of the electric IR curing technology. Tests and daily shop use of REVO demonstrate that it consistently cures primer, sealer and paint with just one pass. In fact, the electric technology works so well that the sealer layer is not required. Elimination of sealer is a game-changing step for North America. We expect it to take some time, but repair shops should begin to eliminate the sealer as they experience the benefits of using electric IR curing technology.
Preparation and Temperature
One of biggest differences between gas catalytic drying and electric IR curing equipment is that the gas must be preheated to 200°F to start the chemical reaction that generates the heat. Since preheating takes about 10 minutes, it is common for collision repair shops to keep the unit on all day despite the additional costs and the potential safety hazard for workers. If preheated, a gas catalytic machine takes about a minute to get up to drying temperature. Electric units take just a fraction of a second. Reaching full bulb temperature almost instantly means that electric IR units are immediately ready to cure the repair and can be turned on only when needed and then turned off. With electric IR, cool down is very quick, so it is safe to touch the machine shortly after shut-down.
Another preparation difference between gas catalytic drying and electric IR curing technology is how the product data sheet is used. For proper drying with a gas catalytic unit, alterations must be made to the directions on the data sheet from the coating manufacturer. Workers must be trained to look for the mixing and/or application changes required by the gas catalytic equipment supplier. Electric IR units do not require changes to the coating manufacturer’s directions. The product data sheets can be used as written.
Temperature consistency and intensity also vary by IR technology. Since natural gas is heavier than air, it tends to drop to the bottom of catalytic plates. Offsetting this drop, the gas flow is directed to the center of the plate and once the catalytic reaction occurs, the heat naturally rises. These inconsistencies can vary the drying over the area of repair. Operators must be trained to compensate for these differences in drying. In addition, gas pressure impacts the catalytic reaction that controls the temperature. Adjusting gas pressure can be difficult, so controlling the temperature is more difficult. Temperature is very important, of course, for proper drying. Gas catalytic IR heats the air around the plate, effectively raising the temperature beyond the area where the heat is directed. The heat variability and high temperature beyond the drying area mean plastic components near the repair site such as side mirrors, trim and handles must be specially masked off to prevent damage. The special masking materials and the labor involved add cost to the repair.
Electric IR energy coming from a bulb stays right where the bulb is located, leading to more consistent heat. Consistency also comes from controlling the temperature; control on an electric unit is easy and very precise. Electric bulbs can be easily adjusted to emit heat from 0 to 100% of capability. Since electric IR technology generates mostly short waves and short waves efficiently heat the substrate, operating temperature can remain lower. This lower temperature will not damage plastic components, so special masking is not necessary when using electric IR drying.
Cycle Time Savings and Throughput Increases
Both IR options do an excellent job of helping to reduce cycle time and significantly increase paint shop throughput. Gas catalytic differences vs. electric for cycle time are driven by how the drying takes place and how the equipment operates. As mentioned earlier, natural gas fueled machinery dries a repair one coat at a time, which means that the equipment must make multiple passes over the same area to get most coatings dry. Electric technology, with its short wave energy, cures from the inside out, so one pass is enough to heat the substrate and complete the cure.
Energy costs are affected by both the amount used and the cost of the fuel. In the electricity fueled IR units, all of the heat energy transfers directly to the substrate to be used in the curing process. With gas catalytic systems, some of the heat is lost in the air, as described earlier. Thus, electric IR units are more energy efficient. Additionally, the gas-burning device often operates all day while the electric IR system is off until needed. As a result the total amount of energy consumed in a day is frequently greater with the gas-powered system. Even if the gas-powered system is turned off between jobs, a preheating time of 10 minutes is required to bring the unit to drying temperature.
Also of note, electricity is a renewable resource. Further, if electricity is produced by solar panels, it can be an exceptionally low cost to the user. As a natural resource, natural gas is subject to much more instability in price over time. The US Government graph below illustrates the complexity and long-term variability of natural gas costs. As seen in the electricity graph, while electricity has gone up in cost, the pattern of cost increases is both consistent and predictable over many years. Government controls over electricity have a lot to do with the consistency and relatively flat progression of cost over time.
Versatility, Maintenance and Service
Whether powered by natural gas or electricity, IR units are easy to use and come in a variety of shapes and sizes to match the drying need. For example, REVO offers four systems: half arch, compact, economy and handheld units for technicians to cure just about any coating anywhere in the shop. Though both IR technologies are versatile, there are some differences for the operators of gas catalytic vs. electric IR. With the gas catalytic machines, care must be taken when the machine is preheating or kept on all day because the ceramic plates are hot and heat the air around them. The warmer environment in the area-of-use and the hot equipment may impact worker comfort and safety. Once the gas catalytic unit is turned off, the plates remain hot for about 15 minutes, so workers must use extreme caution moving the unit. Electric IR technology does not warm the air significantly and is cool to the touch soon after turn-off.
Maintenance also presents several differences. Natural gas technology must be carefully cleaned by an expert several times per year to keep it in peak running condition. Overspray near the unit can leave paint or other coatings on the ceramic plates and should be removed by a service expert. The small holes that create the catalytic reaction must be kept open for proper operation. Over time, natural wear and tear of the ceramic plates occurs because natural gas is corrosive. Eventually the ceramic plates must be replaced, which is costly. Manufacturers suggest replacement of the equipment after approximately 12 to 15 years. In Europe, yearly safety inspection of gas valves and pipes is mandatory.
For electric IR curing equipment, maintenance is also very important. A service expert should inspect the equipment twice per year. Overspray can be easily cleaned off bulbs by shop technicians. Like other electric equipment, bulbs must be replaced periodically after an average life of 12,000 hours. With REVO systems, we suggest that the equipment should last between 15 and 20 years.
This Tale is Just Beginning
IR drying technology is just starting its growth trajectory in North America. It will grow rapidly because of its outstanding economic advantages. As you consider the investment for your shop, make sure you evaluate both gas catalytic and electric technologies. Equally important, be sure to ask about maintenance and service in your area before you make a decision. Though the investment in either gas catalytic or electric IR equipment is sizeable, payback is fast and the benefits exciting. Without changing your shop footprint, you could increase your paint shop throughput by up to 80% by installing IR technology today.