Electrically Heated Rollers Are Top Technology Choice

The Thermalon line of electrically heated rollers from American Roller Co., Union Grove, WI, has won the 2000 Technology of the Year Competition sponsored by the Assocation of Industrial Metallizers, Coaters and Laminators (AIMCAL), Fort Mill, SC.

The patented and patent-pending rollers, available in two styles, use electrical resistance to generate heat and transfer the warmth in a uniform and controlled manner. A solid-state control system senses temperature, provides control and power switching, and enables the rollers to interface to existing computerized or PLC machine controls.

Conventional and proprietary heat pipe technology provides temperature uniformity across the roller face within +/-1 deg C, an impressive feat, according to the judges. Designed to replace complex hot oil, water, and steam-heated rollers, the Thermalon line reportedly can compete on a cost/performance basis with induction-heated and other electrically heated rollers.

The Thermalon RC100 incorporates ceramic materials thermally applied a fraction of an inch below the outer surface of a conventional core to form a thin, homogenous heater element, which covers the entire roller face and generates radiant heat. Since heat is generated only on the outside of the roller, that surface is the first area to reach the desired setpoint. The rollers convert 100% of the energy received into heat.

For applications requiring roller temperatures up to 350 deg F continuously, the RC100 roller provides rapid warmup and nearly instantaneous response to process temperature changes, without overshooting the temperature setpoint. This is said to be useful particularly in situations where tight temperature control is needed or for start/stop applications with minimal wasted product.

While the initial investment may be slightly higher than with liquid-heated rollers, the long-term energy savings, improved process control, and reduction in maintenance more than make up for the difference in purchase price, American Roller notes.

For applications in which an external ceramic covering would not be suitable, the Thermalon RI200 roller incorporates internally mounted resistance heaters while providing the same temperature uniformity and control with minimal setpoint overshoot. The RI200 operates to temperatures up to 500 deg F and can accommodate three-phase power as well as a virtually unlimited variety of cover materials, including abrasion-resistant, high polished ceramic, conventional rubber, and high-release formulations.

The Thermalon RI200 roller is well suited for high-pressure laminating, adhesive or web melting, web preheating (upstream of another process such as laminating), heat stretching (film orientation), embossing, calendering, point bonding of nonwovens, and application of heated or hot melt coatings. The total heater power for a given size roller (watt density at the roller surface) can be up to double what an induction-heated system can offer in the same temperature range. For the user, these features mean higher line speeds and superior process control with performance comparable to more expensive induction-heated systems, according to American Roller.

Improved temperature uniformity and control, reliability, heating capacity, and responsiveness of the Thermalon RC100 and RI200 electrically heated rollers enable converters to improve product uniformity and quality, while increasing production rates and reducing scrap. Judges were impressed with the widespread application potential the technology has in the converting industry. "The rollers address many different needs in the industry," they said.

There were also two finalists in the 2000 AIMCAL Technology of the Year competition: Sigma Technologies International Inc., Tucson, AZ, for a patent-pending Atmospheric Plasma Treatment System; and BPS Inc., Hudson, NH, for its HTC Control System for aluminum evaporation in metallizers.

The APT 1000 Atmospheric Plasma Treatment system cleans and activates the surface of moving webs to improve adherence of subsequent printing, coating, laminating, or metallizing and is said to offer several advantages over conventional corona or flame treatment. Use of specialty gases and electrode design enables the plasma system to activate surfaces such as polytetrafluoroethylene, which previously have been difficult or impossible to treat; produces higher and longer lasting treatment levels; and eliminates the need for backside treatment. The plasma process produces better uniformity than corona treatment with less surface damage and ozone formation, according to Sigma. Advantages over flame treatment are said to include elimination of the combustion hazard, a wider range of treatment chemistry, and compatibility with slow-moving substrates.

The HTC Control System for the evaporation boats used in metallizers reportedly provides a more harmonic power feed, which results in a more constant and symmetric power supply. As a result, power is used more efficiently, wetting of the boats is more uniform, pinholes are reduced 60%, and boat life is extended at least 20%, all of which reduce metallizer operating costs.

The 2000 AIMCAL Technology of the Year award winners were recognized on March 16 at the association's awards banquet during its 2000 Winter Management/Marketing Meeting at the Rancho Bernardo Inn, San Diego, CA.

The judging for the competition was moderated by committee chair Steve Sedlak, product manager at Wacker Engineering Ceramics Inc., with judges Dr. Ed Cohen, AIMCAL technical consultant; Debbie Donberg, managing editor, Paper, Film & Foil CONVERTER magazine; Mark Foote, VP, Packaging Partners LLC; John Marcantonio, president and CEO, Singulus Technologies Inc., and Mark Spaulding, editor-in-chief of Converting

Headquartered in Fort Mill, SC, AIMCAL is an international, nonprofit trade association representing converters of metallized, laminated, and coated flexible substrates and their suppliers. Visit AIMCAL at aimcal.org.



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