Once technicians load the clear polymer rolls into high-vacuum metallizing chambers, the transformation into a reflective mirror begins. The chamber drops to pressures below 10⁻⁴ torr to eliminate ambient air molecules that could interfere with the coating.
Inside the metallizer, reels of 99.99% pure aluminum wire touch ceramic evaporation boats heated to approximately 1,400°C. The aluminum instantly vaporizes, turning into an upward-surging cloud of gaseous metal atoms. The PET film unspools across chilled rollers at speeds exceeding 1,500 feet per minute, allowing the aluminum vapor to condense directly onto the plastic.
This deposition layer measures only 20 to 50 nanometers in thickness. Despite its extreme thinness, it yields near-total optical reflectivity, turning transparent film into an impenetrable silver mirror.
