Polycarbonate (PC) resin is a high-performance thermoplastic widely used in industries such as electronics, automotive, medical devices, and optical applications due to its exceptional impact resistance, transparency, and thermal stability. Common Drying Equipment: Countinius disc dryer
Polycarbonate (PC) resin is a high-performance thermoplastic widely used in industries such as electronics, automotive, medical devices, and optical applications due to its exceptional impact resistance, transparency, and thermal stability. However, PC resin is hygroscopic, meaning it readily absorbs moisture from the environment. Proper drying of PC resin prior to processing is critical to ensure optimal product quality and performance.
Why Drying is Essential
If undried PC resin is subjected to high-temperature processing (e.g., injection molding or extrusion), trapped moisture can cause hydrolysis, leading to molecular degradation. This results in defects such as splay marks, bubbles, reduced mechanical strength, and compromised optical clarity. Even small amounts of moisture (above 0.02% by weight) can adversely affect the final product.
Recommended Drying Parameters
PC resin typically requires thorough drying at temperatures between 120°C and 135°C for 2–4 hours, depending on the resin grade and initial moisture content. A desiccant dryer or dehumidifying hopper dryer is commonly employed, maintaining a dew point below -40°C to ensure efficient moisture removal. Spread the resin in thin layers or use fluidized bed drying to enhance uniformity.
Common Drying Equipment
Countinius disc dryer:
The material flows through the surface of the drying disc along the index helix, and the material on the small drying disc is moved to the outer edge, and falls to the outer edge of the large drying disc below the outer edge of the large drying disc, and the material on the large drying disc moves inwardly and falls into the next layer of the small drying disc from the middle of the material drop port. The size of the drying discs arranged alternately up and down, the material to flow continuously through the entire dryer. Hollow drying disc into the heating medium, heating medium form of saturated steam, hot water and thermal oil, heating medium from one end of the drying disc into the other end of the export.
Key Considerations
Pre-drying Storage: Store PC resin in sealed containers or moisture-proof bags to minimize moisture absorption.
Avoid Overdrying: Prolonged exposure to high temperatures may degrade the resin. Follow manufacturer guidelines.
Post-drying Handling: Process dried resin immediately or store it in a dry environment to prevent reabsorption of moisture.