I. Core Process Optimization Based on Material Thermal Stability
High Heat-Resistant and Stable General-Purpose Materials (PP, PE, ABS, PS): Utilize a rapid heating rate of 3-4℃/min, allowing 100% full power output throughout the process to maximize heating time.
Hold to 100℃ for 10 minutes, then hold at the lower processing temperature for 10 minutes, keeping the total heating time under 45 minutes.
Check the temperature every 20 minutes, ensuring it does not exceed the material's recommended processing upper limit by 10℃. Complete material feeding within 30 minutes of reaching the production temperature.
Medium Heat-Resistant Engineering Materials (PC, PA6, PA66, PMMA): Utilize a heating rate of 2-3℃/min, rapidly heating at full power until 100℃, then limiting power to 80% after 100℃ to avoid temperature overshoot and fluctuations.
Hold to 100℃ for 15 minutes, then hold at the lower processing temperature for 15 minutes, keeping the total heating time under 75 minutes.
Before heating, ensure the material is fully dry, with a moisture content ≤200ppm to avoid hydrolysis and degradation at high temperatures. After reaching the processing range, inspect the material every 10 minutes.
For highly biodegradable materials (PVC, POM, PET, TPU): Use a slow heating rate of 1~1.5℃/min, limiting power to 60%~70% throughout the process. Rapid heating is prohibited.
Hold the material at 100℃ for 20 minutes, then at the lower processing temperature for another 20 minutes, extending the total heating time to over 120 minutes.
Once the temperature exceeds the material's safety threshold, inspect the material every 5 minutes, simultaneously monitoring odor and spillage to identify early signs of degradation.
II. Targeted Optimization Based on Material Specific Properties
Glass fiber reinforced materials: The heating rate is 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: The heating rate is reduced by 20% compared to the same substrate, and the holding time in the mid-temperature section is extended to ensure uniform melt temperature within the runner and avoid poor filling dispersion.
Optical-grade transparent materials: The heating rate is reduced by 30% compared to the same substrate, and the temperature difference throughout the runner is controlled within ±2℃ to avoid poor light transmission and stress marks caused by localized temperature differences.
III. Cross-scenario linkage 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 reduced by 30% compared to the corresponding standard value to avoid excessive temperature differences between the inside and outside of the large-mass runner plate, which could lead to thermal deformation.
If any signs of degradation appear during the heating process, the hot runner temperature is immediately reduced to below the material's glass transition temperature. The melt within the runner is quickly replaced with a specialized cleaning agent. The fault is identified before resuming heating.
