What low dielectric constant materials can be used for insulation layers?

You are currently required to select low dielectric constant materials for hot runner conductor insulation. Based on our earlier knowledge on maximizing distributed capacitance and lowering low-pass filtering effects in hot runner conductors, the following mainstream materials are appropriate:

Polytetrafluoroethylene(PTFE): Dielectric constant is about 2.0~2.2, high temperature resistance up to 260 ℃, excellent for hot runner high temperature environment, mainstream material often used in this scenario.

Fluorinated Ethylene Propylene(FEP) - dielectric constant about 2.1 - melt extrusion processing - uniform insulation performance - long-term operating temperature up to 200℃ - appropriate for medium and low temperature hot runners

Fuseable Polytetrafluoroethylene (PFA): Dielectric constant about 2.1, good high temperature stability, long-term operating temperature up to 260°C, improved mechanical strength compared to standard PTFE, suited for high load hot runners.

Polyimide (PI) films have a dielectric constant of around 3.1 to 3.5, are super thin, and can survive temperatures above 300 °C. They can serve as an auxiliary insulating layer to lower further the total distributed capacitance.

These materials are effective to reduce parasitic capacitance between conductors and metal casing, to diminish the low-pass filtering effect, and to prevent thermal shock cracking due to lag of the thermal runner temperature control signal.