Vacuum dryers have moulding machines in operation in the new medical cell of Mack Molding

"As the provider of the medical market, it is important to maximize the uptime of the machine for products that require frequent changes of resin and tools", said Revane. "Some of the products of our customers should occur in small batches of 100 pieces or less, and in a multitude of colors." "With a dryer LPD on each press, the resin to the next job is dry and ready for use at the time that the new tool is installed."

The key to the versatility of the LPD dryer is that it has a cycle of drying much shorter and a smaller batch size than conventional dryers for drying agent, according to Mark Hamilton's Hamilton Plastics Equipment, LLC and Maguire sales representative. "The LPD system dried resin in just one-sixth of the time required with conventional dryers: literally 40 minutes or less, rather than the four hours needed with a drying agent system", said Hamilton. "And because the LPD dryer has a mechanism of advance of three stations that supplies resin processing machine while another batch is drying, it is possible to work with small batch sizes and still maintain an ongoing process."

When Hamilton spoke for the first time with Mack Molding on the dryers Maguire, Tom Revane was skeptical. "Mark convinced us to use a dryer as proof." Our first test was with a resin of polycarbonate with a content of initial humidity of 0.24 per cent. After 25 minutes in the dryer, moisture slipped to 0.03 per cent. "When many more tests have shown that the LPD dryer worked quickly and uniform, we ask a machine for each of the presses of our medical cell."

Mack Molding is a pioneer in the processing of plastics was founded in 1920 and is currently a molder to order, manufacturer of metals, and manufacturer contractor of full service with annual sales exceeding USD $270 million. The company has plants in seven locations in EE UU., operates 28 to 4,000 tons injection moulding machines and employs 1,800 people. Mack offers services of design, engineering, manufacture of prototypes and manufacture complete. In 2007, Mack Molding was named the plastics processor of the year by the specialized publication Plastics News.

In November 2007, Mack had launched the new cell of medical in Arlington, Vermont, moulding as last step to realize a strategic decision in 2000 to expand the participation of the company in the medical market, according to Carl Bickford, Manager of the central plant. The completely closed cell uses a positive differential pressure and fine particulate filters to provide a protective barrier for the moulding of medical products. Its own staff of operation and technical resources has and operates 24 hours a day.

Resins processed on a regular basis in the cell of medical molding are polycarbonate, poliarilamida, polifenilensulfona, ABS; Nylon with load of glass, polypropylene and elastomers thermoplastics; formulations both optically transparent and opaque are processed. Because some of these materials are especially difficult to dry properly, the speed and efficiency of drying of the LPD system and the small size of their lots of drying are particularly advantageous with Revane. "No to worry about the cumulative drying time and the degradation of the polymer", he said.

In addition to the speed of drying and a small lot size, another benefit that mentioned Maguire for the LPD dryer is a substantial reduction in energy consumption, up from 80 per cent on the former agent secant dryers used today. Although the dryers for drying agent pass hot and dry air on the granules or pellets to slowly remove moisture and then use a drying agent to adsorb the moisture, the LPD dryer uses a vacuum to reduce the boiling point of waterbecome water vapor humidity quickly and literally pulling the vapor of water inside of the pellets. The need of the desiccant is removed and with it the cost of regenerate it, which adds to the cost of energy from conventional dryers.