“Total sales of the LPD dryer now exceed 1,400 units and are increasing at the rate of 30 units per month,” said B. Patrick Smith, vice president of marketing and sales. “We fully expect that the new enhancements of this revolutionary dryer will lead to even faster growth.”
Smith summarized the benefits for users as follows:

• Faster and more uniform heating. “By redesigning the airflow circuit within the drying canister, we have increased the speed of a system that already had been yielding properly dried resin in one-sixth of the time required with a conventional desiccant dryer,” Smith said. “In addition, the drying process is more uniform throughout the resin batch than is possible with a desiccant dryer, maintaining the consistency of the resin fed to the processing machine and reducing the likelihood of defects due to overexposure of the polymer to heat.”
   
• Increased throughput for high-heat resins. Maguire has stepped up the pre-heating capability of the LPD dryer from 300 °F (150 °C) to 365 °F (185 °C), thereby shortening drying time for materials ranging from PET to polysulfone, polyethersulfone, and polyetherimide.
   
• Easier purging of pellets in conveyor lines. New software provides for purging of conveyor lines from the dryer to the processing machine, removing residual pellets that could otherwise regain moisture.
   
• Easier deployment as a central dryer. A new manifold system provides conveyance to multiple processing lines.
    
• Easier adjustment to ambient conditions. Since vacuum pressure varies widely from one region to another (being much lower at high altitudes than at sea level, for example), the pressure in the LPD dryer must be adjusted accordingly. A new vacuum calibration capability built into the controller software replaces a manual task with an automated one.
    
• More user-friendly controller interface. A new two-line, 40-character vacuum fluorescent display (VFD) provides detailed messaging and can be set to deliver text in English, Czech, Dutch, French, German, Italian, and Spanish.
    
• Faster material changes. Two new features reduce the time between color or product changeovers: an easy-access surge hopper and a built-in drain chute for emptying resin canisters. The latter feature is particularly valuable with large-capacity dryers.
   
• Instant validation of dryer operation. Maguire has placed a window at the top of the canister, through which a sensor can detect the presence of resin at that level inside. This new system enables the operator to become aware of a loader malfunction and prevents overfill.

“Compared with hot air and desiccant dryers, the LPD vacuum dryer requires only 20% of the energy and one-sixth of the time to properly pre-dry resin,” said Smith. “We anticipate that by providing these and other benefits, the LPD dryer will change the way the industry dries resin.”

The LPD dryer differs radically from conventional hot-air and desiccant dryers in two ways: 1) instead of flowing hot, dry air over the pellets to slowly draw the moisture out, the patented LPD dryer uses vacuum to reduce the boiling point of water, quickly turn the moisture into water vapor, and literally pull the water vapor from within the pellets; and 2) the LPD dryer carries out heating and vacuum drying simultaneously in separate stations, making possible small batches while in effect transforming a batch process into a continuous one that keeps pace with the processing machine.

MAGUIRE PRODUCTS, INC., headquartered in Aston, Pennsylvania, U.S.A., is the world’s largest supplier of gravimetric blenders and liquid color pumps and also manufactures loading systems, granulators, dryers, auger feeders, and related equipment and software. Its customers include injection, blow, and rotational molders, extrusion processors, and compounders. Founded in 1977, Maguire operates five manufacturing facilities in Aston and Smithfield, Rhode Island, U.S.A. The company maintains a network of distributors in the Americas and overseas and has two sales and service subsidiaries: Maguire Europe, which supports customers throughout Europe and operates a distribution center in Tamworth, Staffordshire, United Kingdom; and Singapore-based Maguire Asia, serves customers throughout South Asia and the Pacific Rim. Visit the Maguire Products web site: www.maguire.com.