WATER REPELLENT POWDER DRYING METHOD, PRODUCTION PROCESS AND PRODUCTION APPARATUS

摘要

Half-finished product obtained as a mixture of PTFE powder and water is placed on delivery trays (70) and introduced in production apparatus (10). In the production apparatus (10), vertically arrayed delivery trays (70) are driven so as to sequentially pass through first drying zone (41), second drying zone (42) and heat treatment zone (43). In the first drying zone (41), water contained in the half-finished product is evaporated by microwave heating. In the second drying zone (42), any water remaining in the half-finished product is evaporated by hot water heating. In the heat treatment zone (43), the temperature of the dried PTFE powder is maintained at about 160°C. The half-finished product placed on the delivery trays (70) becomes PTFE powder as a final product by sequential pass through these three zones.