What are the drying recommendations for Eastman Provista™ copolymer?
Drying Eastman Provista™ copolymer properly is critical to the success of the extrusion process. Make sure that the resin is appropriately dried before starting to extrude. • Type of dryer: automatic, desiccant. • Air dryness: dew point –40°C (–40°F) or lower. • Air temperature: maximum 65°C (150°F) at the hopper inlet. • Circulation: 0.060 m3/min of air per kg/h [(1.0 ft3/min of air per lb/h)] of plastic to be dried and not less than 6 m3/min (100 ft3/min) per unit. • Monitors: (a) hopper inlet thermometer, (b) dew point monitor. • Hopper size: 6–10 times the hourly poundage to be dried. (Hold-up capacity depends on maximum expected incoming pellet moisture content.) • Make sure your production rate is not faster than the amount of material that can be dried within 4 hours. • Hopper shape: For good air and pellet flow, a tall, slender hopper should be used versus a short, large diameter design. • Target moisture level: 0.04% or less.
