PTFE is a polymer material made from tetrafluoroethylene, commonly known as the "king of plastics." Its molecular structure resembles a "carbon chain wrapped in fluorine atoms"-each carbon atom is symmetrically connected to two fluorine atoms, completely encasing the carbon chain and forming an "inert shell."
A "capillary" is one form of this material: typically with a diameter between 0.1 and 5 millimeters and a thin wall thickness (0.05-1 millimeter), resembling a fine tube. This shape allows it to pass flexibly through narrow spaces while maintaining excellent mechanical strength.