PET/Fluoropolymer-Based Release Film for Fabricating Self-Standing Coating Film, CPETFPRF

PET-supported fluoropolymer release films (often designated as fluorosilicone or pure fluoro-coated PET liners) represent a highly specialized class of transient carriers engineered for precision roll-to-roll (R2R) or slot-die coating.

Unlike standard silicone-coated liners, which are the industry default for pressure-sensitive adhesives and general packaging, a fluoropolymer-modified release surface is deployed specifically to handle aggressive solvents, high processing temperatures, or components that are strictly intolerant to silicone contamination—such as solid-state battery (ASSB) electrolyte slurries, dry-processed battery electrodes, fuel cell membranes, and multilayer ceramic capacitors (MLCCs).

Standard silicone-coated PET liners rely on a polydimethylsiloxane (PDMS) network. While highly effective for conventional applications, they present severe failure mechanisms when used as a casting substrate for next-generation functional energy materials: (1) Elimination of Silicone Poisoning: In advanced battery manufacturing, if a silicone release liner is not completely cured, free silicone monomers/oligomers will migrate directly into your cast separator or solid-state electrolyte slurry. Microscopic silicone contamination acts as a local electrochemical insulator, preventing proper wetting of the ionic network and causing localized high impedance. Pure fluoropolymer coatings eliminate this risk entirely. (2) Chemical Resistance to Aggressive Casting Solvents: Precision slurries often utilize harsh organic solvents such as N-Methyl-2-pyrrolidone (NMP), toluene, or xylene. These solvents can swell or partially dissolve standard silicone networks, destroying the smooth interface of the release layer. Fluoropolymers possess exceptional chemical inertness and remain entirely unaffected by aggressive solvent matrices. (3) Handling Silicone-Based Formulations: If the functional layer you are coating inherently contains a silicone gel, silicone binder, or silicone pressure-sensitive adhesive, a standard silicone release liner will cause "cure inhibition" or will permanently bond (lock up) with the coating. A fluoropolymer liner provides the necessary surface energy differential to allow a clean, low-effort peel.

References:

1. Y. Zou, et al., The study of PET recyclable polymers as paper coatings, Progress in Organic Coatings, 2007, 60, 127-131
2. Y. Li, et al., Flexible non-adhesive PDMS/PET release film for reducing separation force in bottom-up vat photopolymerization 3D-printing, Applied Surface Science, 2026, 737, 166876