Microwave drying process for synthetic polymers

摘要

Volatile polar vehicles such as water or organic solvents, are removed from nonpolar materials by passing said material through at least one pneumatic conveyor resonating cavity operating at a microwave frequency of about 600 to about 50,000 MHZ. For example, a polymer such as polyvinyl chloride may be dried by conveying the polymer through said pneumatic conveyor operating at a frequency of 915 MHZ for a time sufficient to reduce the volatiles content to about 5 wt. % and subsequently conveying the partially dried material through a second pneumatic conveyor resonating cavity operating at a microwave frequency of 2450 MHZ for a time sufficient to reduce the polar vehicle content to below 0.5 wt. %.