I. High Heat Resistance and Stability General-Purpose Materials (PP, PE, ABS, PS)
Heating Curve Optimization: Employ a rapid heating rate of 3-4℃/min, allowing 100% full power output throughout the process. Hold at 100℃ for 10 minutes, and hold at the lower limit of the processing temperature for 10 minutes. The total heating time can be reduced to within 45 minutes.
Process Control Optimization: Check the temperature every 20 minutes, ensuring it does not exceed the material's processing upper limit by 10℃. Complete material feeding within 30 minutes of reaching the production temperature to maximize production efficiency.
II. Medium Heat Resistance Engineering Materials (PC, PA6, PA66, PMMA)
Heating Curve Optimization: Employ a heating rate of 2-3℃/min. Rapidly heat to full power before 100℃, then limit power to 80% after 100℃. Hold at 100℃ for 15 minutes, and hold at the lower limit of the processing temperature for 15 minutes. The total heating time should be controlled within 75 minutes. Process Control Optimization: Before heating, ensure materials are fully dry with a moisture content ≤200ppm to avoid hydrolysis and degradation at high temperatures. After reaching the processing range, inspect every 10 minutes, ensuring the temperature does not exceed the recommended processing limit by 5℃.
III. Highly Degradable Sensitive Materials (PVC, POM, PET, TPU)
Heating Curve Optimization: Use a slow heating rate of 1~1.5℃/min, limiting power to 60%~70% throughout the process. Hold at 100℃ for 20 minutes, and at the lower processing limit for 20 minutes, extending the total heating time to over 120 minutes.
Process Control Optimization: After the temperature exceeds the material's safety threshold, inspect every 5 minutes, simultaneously monitoring odor and overflow status to identify early signs of degradation immediately. PVC processing temperature is strictly controlled at 160~180℃. POM must be added within 15 minutes of reaching production temperature. PET moisture content must be ≤50ppm before heating.
IV. Process Optimization for Special Modified Materials
Glass Fiber Reinforced Materials: Heating rate increased by 10% compared to the same substrate, allowing 90% power output throughout the process without additional speed control, balancing efficiency and stability.
High-Filling Materials: Heating rate decreased by 20% compared to the same substrate, extending the holding time in the mid-temperature section to ensure uniform melt temperature within the flow channel and avoid poor filling dispersion.
Optical-Grade Transparent Materials: Heating rate decreased by 30% compared to the same substrate, controlling the temperature difference throughout the flow channel within ±2℃ to prevent poor light transmission and stress marks caused by localized temperature differences.
V. Cross-Scenario Optimization Rules
In high-humidity, rainy environments, all materials undergo an additional 10 minutes of dehumidification and heat preservation at 100℃ to ensure sufficient moisture removal and prevent hydrolytic degradation.
For ultra-large multi-cavity hot runners with 64 cavities or more, the heating rate of all materials is decreased by 30% compared to the corresponding standard value to prevent excessive temperature differences between the inside and outside of the large-mass flow channel plate, which could lead to thermal deformation.
If any signs of degradation appear during the heating process, immediately lower the hot runner temperature to below the material's glass transition temperature, quickly replace the melt in the runner with a special cleaning material, troubleshoot the problem, and then restart the heating process.
