Meaning
Physical recycling process that separates target polymers from mixed plastic waste by dissolving them in a selective solvent and then recovering them as pure resin. Utilizing total dissolution precipitation allows for the recovery of high-purity polymers from multi-layer films or heavily contaminated post-consumer plastic waste. This technology bypasses the limitations of mechanical recycling by removing additives, colorants, and composite layers at the molecular level.
Chemical Mechanism
The mixed plastic is exposed to a hot solvent that selectively dissolves the desired polymer while leaving other plastics and contaminants in solid form. Once separated by filtration, the dissolved polymer is precipitated out of the solution by adding a non-solvent or by cooling. The recovered polymer is then dried and pelletized, yielding a resin with properties close to those of virgin material.
Process Efficiency
Solvent recovery is the primary factor determining the economic viability and environmental impact of this recycling method. Modern plants must recover and reuse more than ninety-nine percent of the solvent to minimize operating costs and prevent emissions. Efficient solvent management ensures that the process remains competitive with the production of virgin resins.
Application Scope
This extraction method is effective for recycling hard-to-process materials such as brominated flame-retardant housings or multi-layer packaging films. The recovered polymer contains minimal residual additives, making it suitable for demanding applications where mechanical regrind cannot be used. This process extends the range of recyclable materials and supports the circular economy.
