The Ransburg PPS 2001 electrostatic spray system, compared to earlier systems, is said to supply more material per bell with greater consistency. This can permit line speeds to be increased without quality loss.
Installing a finishing system can be a costly proposition. Besides considerable capital expenditures, it may take a lot of floor space and, when replacing an older system, temporarily disrupt production.
One major refrigerator maker reportedly used its ITW Ransburg (Toledo, OH, U.S.) liquid finishing system for 30 years. The company eventually replaced it with a new Ransburg system to handle newer finishing materials and the company's growing production. At the other extreme, some companies have partly or completely gotten out of finishing by using pre-coated coils or contracting for pre-coated blanks.
For those companies that do their own finishing, keeping an eye on the material and technology advances and production options can pay off. For instance, one maker of storage products changed to automated powder equipment that allowed spraying of wire shelves in a four-across configuration, rather than back to back. The new system, from ITW Gema (Indianapolis, IN, U.S.), has higher first pass transfer efficiency, more efficient electrostatic control to allow for better weld coverage, and more uniform delivery control at reduced powder flow rates. Average powder savings were 32 percent in the first 3 months.
Many appliance companies have switched to powder coating. This technology continues to evolve as an economical alternative. Powders offer a wide range of colors and textures, and can often be applied more efficiently and at a lower cost than alternatives.
Solvent reduction is one advantage of powder coating use, but some other coatings also do well. BASF Coatings (Munster, Germany) has introduced the Cathoguard 500C electrocoat system, which is lead-free and has a solvent content of less than 1 percent. The material is said to provide good corrosion protection in cavities and along edges. During application, the main advantages are reportedly good flow and a high first-run success rate.
For high-volume spray-on finishing, automation usually makes sense. While robots are unnecessary in most volume finishing applications, there are cases when they can supplement the work of simpler automation. "For instance, one company uses a robot to cut in and reinforce corners in ovens, using porcelain enamel powder," observes Mike Dilday, Fanuc Robotics (Toledo, OH, U.S.). "This improves film consistency and the cavity appearance. A robot can minimize the need for manual reinforcement, which can be slower and less precise."
It behooves appliance companies to have an open channel to coating suppliers. They can be a conduit for advantageous materials developments. For information on how Whirlpool benefited through a supplier's one-coat white electrocoat system development, "One Coat Covers All".
The same type of connection is valuable with metals suppliers. In enameling steels, for instance, Charlie Summers, technical service manager at steel service center Mapes & Sprowl Steel Ltd. (Elk Grove Village, IL, U.S.), says that choices are limited to three grades of steel, and there are only four North American producers. "But if you have issues with a given product, such as with ductility or breakage, or enameling aesthetics, we can look at the trade offs and use our knowledge to make recommendations," he says. "Even though we are just one link in the chain - we don't produce the steel, the enamel, the furnaces, and so on - we keep in touch with the other links. That way what we recommend is not at cross purposes with what the OEM is doing.
In the equipment area, vendors can help with anything from a partial upgrade to a complete replacement. Following is information on how an HVAC appliance company and an evaporative cooler maker achieved a cleaner spraying environment and more consistent powder finishes with a new system, and how changing spray guns helped a plumbing appliance company.
Materials & Equipment
37 - Out
With The Old?
38 - Don't
Starve Your Spray Gun for Air!
39 - One
Coat Covers All
40 - Spray
Gun Change Enhances Vitreous China
42 - Essick