New compact dryers from Conair (Cranberry Township, PA) that can be mounted on the feed throat of a molding machine or extruder provide the same performance as larger desiccant-wheel dryers, making them advantageous when small quantities of expensive engineering resins are processed. Suppliers serving the medical device industry and other sectors where engineering resins are commonly used will benefit.

Reportedly the smallest wheel-type dryers on the market, the MicroWheel devices are designed as an alternative to compressed-air dryers and small twin-tower units.

"When it was introduced nearly 10 years ago, the Conair Carousel Plus wheel dryer was revolutionary in its ability to hold rock-steady temperatures and dew points, while reducing energy consumption, speeding startup, and reducing maintenance requirements," says Jamie Jamison, Drying Product Manager. "However, even the smallest units were too big for machine mounting and had fairly large throughput minimums, so processors had no alternative but to use other, less-efficient drying technologies."

The new small Conair dryers are offered in two basic models: the MW1 and the MW2. Each model is available with several different hopper capacities.

MW1 units can support hopper capacities of 0.2, 0.5, and 1.0 cu ft (5.7, 14.2, and 28.5 L). Including the hopper, they range in height from 19.5 to 27.7 in. (495 to 704 mm), and the largest unit weighs just 106 lb (48 kg).

The larger MW2 dryer is available for 1.0 and 1.5 cu ft (28.5 and 42.5 L) hoppers, measure 27.7 and 38.5 in. (704 and 978 mm) in height, and the largest unit weighs 144 lb (65 kg).

The speed-controlled blower and controller make it possible to fine-tune drying parameters to achieve perfectly dried material with a minimum of energy input and little chance of over- or under-drying.

The control comes preprogrammed with 30 different recipes for various resins. The user simply identifies the material being dried along with the expected throughput, and the control automatically adjusts temperature and airflow to match resin-supplier guidelines for effective drying. In addition, 20 user-defined recipes can be stored.

Other standard control features include a material protection management system, which automatically reduces process air temperatures when return-air temperatures exceed the set point, and real-time energy consumption monitor.

Standard stainless-steel hopper liners are fully insulated, with a protective aluminum outer shell.

A stainless-steel machine-throat adapter, with resin-discharge port and purging compound input bypass port, is available as an option.