Heat Transfer Gets More Precise

Published: June 30, 2005, By Deborah Donberg, Associate Managing Editor

Product Focus

Talking to suppliers of heat transfer rolls is a little like listening to the weatherman. They all talk about temperatures quite a lot, but there is one big difference: When these suppliers talk about temperatures, they use precise measurements. And they guarantee them!

Matthew Menges, president of Menges Roller Co. (mengesroller.com), says, "Customers today are looking for a guaranteed Delta T across the face, which is a guaranteed temperature range. Being able to provide a guaranteed plus or minus Delta T is relatively new. You used to be able to get some chilling or heating, but the consistency of the wrap of the internal spiral construction now can be done so that a consistent temperature across the face can be guaranteed. Designs have changed to make this possible."

According to Paul Schulz, president of Webex (webexinc.com), everyone wants to run faster today. "That means you need more precise heat transfer characteristics of the roll to have a uniform temperature profile across the roll base. This becomes more critical at higher speeds. Users need a more precisely engineered roll product than what they’ve had in the past."

Schulz adds, "As people increase their speeds and want to increase their productivity and go wider, the need for an engineered product becomes much more pronounced, as does the need for resources that will model the performance and characteristics of a customer’s web handling process: ‘How big a roll do I need?’ ‘What type of roll do I need?’ We are seeing an increased need for that."

Balancing of the rolls for high speeds has improved, says Menges. "You see two shells, a tube and an inner tube, a more sophisticated design to run in balance with the fluids inside." Menges calls heat transfer rolls a value-added product. "For example, you can chill a web quickly and shorten the length of the line. For some heating applications, you can eliminate an entire oven that might be 15 or 20 feet long. So with this value-added tool, you can often heat or cool in a much more contained area."

As people go to wider webs, especially in the plastic film processing industry, they want uniform caliper when they go through a nipping process, Schulz says. "They want to minimize deflection. Customers trying to dial in their process closer and closer to be more precise, to minimize their downtime, make more and more demands for an engineered product [to do this]."

Looking ahead, Menges sees continuing improvement in heat transfer rollers. "There will be more sophisticated machinery to make the rolls. And who knows what applications will come up in the future? Who would have thought of micro-chips years ago?"

"Customers are getting into smaller and smaller increments of where they want to save money in their process," says Schulz. "That goes for both quality and economics. For example, if I replace a simplistic design of what I have—single wall—and put in much more sophisticated, uniform-temperature-profile roll, it provides a more quality sheet as well as less defects and less waste."

As for the materials of the rolls, however, Menges says they haven’t really changed much, and he doesn’t expect them to. "The rolls are made of steel and aluminum, chrome plated or rubber covered. We haven’t gone to carbon fiber yet, and we probably won’t, because steel simply is a better retainer of heat or cooling."

Schulz agrees. "The rolls usually are made of carbon steel roll, chrome- or nickel-plated. Some have a unique matte finish. But the materials are pretty much the standard over the years. Surface finishes are always changing and evolving as products change, but I don’t see a lot of changes with actual materials. It’s a pretty cost-effective product right now for what you’re getting."

At Tokuden (tokuden.com), heat transfer rolls always are a custom product, says VP Kazu Fujimoto. "Customers want a minimum and maximum temperature, a minimum and maximum nip pressure, an exact roll size and speed, and a specific heating capacity." Designs keep changing, Fujimoto says, including how many induction coils can be provided inside of a roll.

While this niche of the industry is not one in which we are likely to see major changes, it is one in which the precision of the product keeps improving. And that means customers are getting precisely what they want.

For heat transfer new products, see our July New Products.

Restrictions of time and space limit the number of companies, products, and trends that we can discuss in these reports. For additional information, see PFFC’s features and departments each month, consult the June Buyers Guide, and search our online archives.