Meaning
Reclaimed thermoplastic resins recovered from municipal recycling streams undergo sorting and washing to prepare them for re-processing. Using post consumer polyethylene terephthalate reduces the environmental impact of plastic manufacturing by substituting virgin resin with recycled material. This reclaimed polymer is commonly sourced from used beverage bottles and thermoformed packaging.
Process Stability
Thermal degradation history and residual moisture content affect the melt viscosity of recycled polymers. When processing post consumer polyethylene terephthalate, the presence of contaminants can cause hydrolytic degradation during extrusion. This degradation lowers the intrinsic viscosity of the melt, making it difficult to maintain consistent part weight.
Pre-drying the resin to extremely low moisture levels is essential to preserve mechanical strength.
Polymer Contamination
Foreign materials such as adhesives, paper labels and alternative plastics reduce the clarity of recycled products. In the production of high-quality products, even trace amounts of polyvinyl chloride in post consumer polyethylene terephthalate cause acid generation that degrades the polymer chains. These impurities lead to black specks, yellowing and reduced tensile strength in the finished bottles.
Advanced optical sorting is required to ensure high purity. Minimizing these contaminants allows molders to use higher percentages of recycled material in high-visibility consumer products.
Economic Consequence
Fluctuations in the supply and price of virgin resin dictate the demand for recycled alternatives. While post consumer polyethylene terephthalate offers cost savings under high oil prices, the cost of collection and purification can make it more expensive than virgin material. Using this recycled resin is therefore driven by sustainability mandates as well as raw material economics.
