We present a low-temperature, solvent-assisted separation process for the recycling of mixed polymer labels derived from polyethylene terephthalate (PET) bottle waste. By integrating ultrasonic deinking with precision density sorting (targeting 1.15 g/cm3), the method effectively distinguishes amorphous PET (A-PET) from polyvinyl chloride (PVC) and oriented polystyrene (OPS) contaminants without mechanical degradation. Pilot-scale implementation achieved PET recovery rates exceeding 94%, with postsorting PVC levels below 100 ppm. Characterization via Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and elemental analysis confirmed the preservation of core PET properties and the absence of ink-associated heavy metals. The process operates under ambient conditions, with energy consumption measured at 0.45 kWh/kg, which is substantially lower than those of thermal and steam-assisted deinking systems. A preliminary techno-economic assessment indicated a monthly net revenue of NTD 550000, as well as a potential for integration into the existing PET recovery infrastructure. Environmental benefits, including reduced solvent emissions and the elimination of incineration, align with national zero-waste goals and global circular economy objectives. These findings support the deployment of automated label decontamination systems as an enabling technology for high-purity PET recycling.