How PVC is Recycled

The sheer amount of additives used in the production of PVC inhibits most large-scale, post-consumer recycling. PVC also inadvertently interferes with the recycling of other plastics when commingled, due to its unique chemical makeup.

More than 7 billion pounds of PVC are thrown away in the U.S., and only 18 million pounds – barely one-quarter of 1 percent – is recycled.

The relatively new mechanical recycling process known as Vinyloop® technology, developed by Solvay Research & Technology, allows the complete separation of PVC material from the non-PVC materials that are often combined with it, such as:

• Polyester fibers
• Glass fibers
• Natural textiles
• Polyurethane foam
• Metals
• Rubber

The Vinyloop Process

1. Pretreatment: The PVC is physically prepared to be reverted back into a raw material. These steps include cleaning or washing, material size reduction by cutting, grinding or milling and a homogenization step.
2. Dissolution: The waste is combined with a selective solvent in a closed reactor that releases the PVC compound matrix. Additives and other materials are either dissolved or remain suspended in the liquid.
3. Separation: Depending upon the insoluble materials, techniques such as centrifuging, decanting and cycloning are used for separation. Following the separation step, the secondary materials are washed with solvent to further remove any remaining dissolved PVC compound.
4. Precipitation: Steam is injected to completely evaporate the solvent. The PVC compound formulation is recovered as liquid slurry. The PVC resin precipitates into microgranules.
5. Drying: The slurry from the precipitation, which is a mixture of process water and regenerated PVC compound, is dried and the process water is treated before discharge. The regenerated PVC compound is now ready for use and is packed to await shipment. The solvent used in the process is contained in a closed loop. More than 99.9 percent of the solvent is recovered and separated from the process water, using condensation and density separation.

The production of each component needed for virgin PVC manufacturing consumes more natural resources, uses more energy, creates more air and water pollution and, overall, has a greater environmental effect than the Vinyloop operation itself. Additionally, the end product of the Vinyloop process is of the same quality.