LOCTITE? ECI 8120 E&C

Loctite ECI 8120 is a specialised, carbon-filled, thermoplastic ink designed for the creation of self-regulating, low-voltage heating elements (< 50 V). Utilising Positive Temperature Coefficient (PTC) technology, it allows the ink to act as its own thermostat. As the material heats up and its electrical resistance increases sharply, naturally limiting the current flow and maintaining a steady-state temperature without the need for external control devices or sensors. This makes it a premier choice for smart heating applications on flexible substrates like PET, PEN, and polyimide.

In its undried state, ECI 8120 is a black paste with a solids content of 46% and a viscosity of 29,000 mPa.s. It is engineered for high-precision screen printing, featuring a thixotropic index of 6.9 to ensure stable dot and line definition. For optimal electrical performance, the ink should be dried for 10 minutes at 140°C using forced air or infrared systems. It is supplied ready-to-use but can be diluted with up to 10% butyl glycol acetate if adjustments are needed for specific screen meshes (typically 54 to 61 mesh/cm).

Once dried, the material reaches a self-regulation temperature of approximately 105°C and boasts a high PTC ratio of 15, providing a clear and well-defined thermal cut-off. It exhibits excellent adhesion (5B grade) to polyester foils and is fully compatible with silver busbar inks like Loctite ECI 1010. To ensure long-term environmental stability and electrical insulation, the printed elements are often protected with a layer of UV-curable dielectric, such as Loctite EDAG PF-455B, which shields the carbon matrix from moisture and physical wear.