Based on our previous background on material identification and troubleshooting of PTFE conductors in hot runner scenarios, the low-pass filtering effect of the distributed capacitance of hot runner conductors is a key issue affecting temperature control accuracy:
Core Principle: The parasitic distributed capacitance formed between the PTFE conductor core and the metal shielding layer/hot runner shell, together with the conductor's own resistance, constitutes an RC low-pass filter circuit, filtering out high-frequency components in the temperature control signal.
Actual Hazards: This effect can cause lag in temperature control signal transmission, leading to deviations between the sampled temperature value and the actual hot runner temperature, resulting in localized overheating, and even thermal shock cracking of the hot runner.
Causes: Inferior PTFE conductors containing recycled materials have an abnormally high dielectric constant, which significantly amplifies the distributed capacitance, exacerbating the low-pass filtering effect, and is a common hidden cause of inaccurate hot runner temperature control.
Alternative solution: Use virgin PTFE wire with low dielectric constant to shorten the signal transmission distance, effectively reduce distributed capacitance, weaken the low-pass filtering effect, and ensure real-time accuracy of temperature control signals.
