Based on our previous discussion of how the distributed capacitance of PTFE conductors in hot runner scenarios causes low-pass filtering effects and affects temperature control accuracy, the following points should be considered when selecting PTFE conductors with low dielectric constants:
Material Identification: Prioritize conductors with 100% pure virgin material and a suspended PTFE insulation layer. The dielectric constant of pure virgin PTFE is stable at around 2.1. Avoid inferior products that are mixed with recycled materials or filled with modified materials, as these will have a significantly higher dielectric constant.
Parameter Verification: Request material testing reports from suppliers to confirm that the dielectric constant of the conductor insulation layer is ≤2.2, and that it has a long-term temperature resistance of ≥260℃ to suit the high-temperature conditions of hot runner systems.
Structure Selection: Prioritize single-core or double-core independent insulation structures without redundant filler layers. Avoid multiple shielding layers being too close to the conductor core, which would increase parasitic distributed capacitance.
Actual testing and verification: Upon arrival, the distributed capacitance per unit length of the conductor was measured using an LCR meter at a frequency of 1kHz. The acceptable value should be ≤100pF/m, and the lower the value, the better the dielectric constant performance.
Through the above steps, low dielectric constant PTFE conductors can be accurately selected, effectively reducing the low-pass filtering effect in hot runner scenarios and ensuring real-time and accurate temperature control signal transmission.
