Novatec Inc. is building three infrared rotary drum dryers, machines the Baltimore company said are the largest IRDs ever built — they dry and crystallize up to 4,600 pounds of PET an hour.
Novatec officials declined to identify the customers. But Mark Haynie, sales manager for dryer products, said all three IRDs are going into PET sheet for thermoforming.
Two of the dryers are going to one customer; the third one is for a second customer. The IRD can prepare moisture-laden PET regrind into usable material.
Haynie said extrusion to make PET packaging, using thin sheet and film, remains one of the bright spots in the plastics industry, even in the economic downturn. Carpet makers are switching to polyester fiber, much of it from recycled PET, because of the cost of nylon fibers, he said.
The IRD is used for PET flake and post-industrial and post-consumer regrind.
Novatec said it is getting lots of customer requests to use its small laboratory-sized IRD, housed at the company's drying technology center. ``This is a one-of-a-kind technology and only Novatec builds it in the U.S.,'' said Conrad Bessemer, president and chief executive officer.
For conventional PET processing operations, Novatec said, the crystallizer can stand up to 23 feet high, which often requires modifications to a factory's floor and roof. The material spends about an hour in the crystallizer before being moved to a conventional resin dryer, where it can spend another four or five hours of drying time.
The IRD process takes about one hour. Infrared rays travel directly into the PET particles without heating the surrounding air. Because the heat is very efficient, the IRD cuts energy costs by up to 65 percent, compared with a conventional desiccant system, according to Novatec.
Company officials explained the process during an interview at the plant in late October.
In the IRD, the PET flake tumbles through a rotating stainless-steel drum, moving past a series of variable-intensity, infrared lamps mounted in the middle of the drum. A series of internal deflectors enhances the tumbling action, ensuring that every surface of the flake is exposed to the infrared heat. A continuous internal helix inside the drum moves the PET forward under the lamps.
The set of infrared lamps is suspended on a carriage on wheels, so it can be removed easily from the drum.
The IRD crystallizes and dries in one operation. Between eight and 15 minutes later, the material exits the IRD with a moisture content of about 100 parts per million. That moisture content is further dried, to 50 ppm, as the resin passes from the IRD through a buffer hopper, which is connected to a desiccant wheel dryer.
The two conventional dryers each are sized for about one-quarter of the total throughput rate of the infrared rotary drum dryer.
Novatec has a licensing agreement for the IRD with Stricker IRD Patent GbR in Vormwald, Germany, and UPM Holdings Ltd. of Berks, England. Novatec introduced the IRD at NPE 2006, by showing a dryer built by UPM.
Haynie said Novatec has been selling about one IRD a month.
Dryers use a large amount of energy in a factory. Higher energy costs are making processors more open to new technologies like infrared heat, said John Gillette, Novatec's vice president of engineering.
``Reducing energy costs is one of the few manufacturing costs over which they have some control,'' Gillette said. ``Processors are basically stuck with rising material costs [and] labor costs, and equipment costs certainly aren't coming down, so reducing energy costs has become a big issue.''
