Polyethylene Terephthalate (PET) is a clear, durable, and lightweight thermoplastic polymer. Formed by the polymerization of ethylene glycol and terephthalic acid, PET is valued in packaging for its strength, clarity, and barrier properties against moisture and gas. PET is one of the most widely recycled plastics worldwide, as its molecular structure allows it to be melted and remolded repeatedly. This high recyclability supports a circular economy and reduces reliance on virgin resources.
Identifying PET Products
Consumers can easily identify items made from this polymer by looking for the Resin Identification Code (RIC). This symbol is a triangle of chasing arrows with the number “1” inside, often located on the bottom or side of the container. This code designates the material as Polyethylene Terephthalate, distinguishing it from other plastic types.
The most common household products utilizing PET are beverage containers, including nearly all water bottles, soda bottles, and fruit juice containers. Other applications include peanut butter jars, clear food containers, and cosmetic packaging. PET’s light weight and shatterproof nature, combined with its ability to safely contain food and beverages, make it the preferred material for these everyday items.
Consumer Preparation and Contamination
The journey to a successful recycling outcome begins with the consumer’s preparation of the material at home. The most important step is to empty and quickly rinse the containers to remove any remaining liquid or food residue. Containers do not need to be perfectly clean, but minimizing residue is necessary to prevent contamination of the entire batch of collected plastic.
Contaminants like oils, chemicals, and leftover food reduce the quality of the recycled material and can lead to entire loads being rejected. The general guidance is to leave the cap on the bottle, even though the cap is often made from a different plastic, like polypropylene (PP). Facilities can efficiently separate these different plastic types later. Leaving the cap on also helps the bottle maintain its shape during sorting and baling, which improves processing efficiency.
The Industrial Recycling Steps
Once collected, used PET containers are delivered to a processing facility where mechanical recycling begins. The first stage is automated sorting, where bales of mixed materials are broken apart. Optical scanners differentiate PET from other plastics by color and resin type. This segregation is necessary because mixing different plastic polymers significantly lowers the quality of the final product.
The sorted PET is then shredded into small, uniform pieces known as “flakes” for deep cleaning. These flakes undergo a hot wash treatment, often involving special detergents, to melt away remaining contaminants such as glue, labels, and food residue. After the hot wash, a float/sink process separates the denser PET flakes (which sink) from lighter plastic contaminants like bottle caps (which float).
The purified flakes are then dried before moving to the final stage of melting and pelletizing. The clean PET flakes are melted at high temperatures and extruded into thin strands, which are then cut into small, standardized pellets, known as recycled PET (rPET). These pellets may undergo further decontamination steps, such as solid-state polymerization, to ensure they meet the purity standards required for food-grade applications.
The Uses of Recycled PET
The resulting rPET pellets serve as a direct substitute for virgin plastic in manufacturing new products. One of the highest-value applications is “bottle-to-bottle” recycling, where rPET is used to create new beverage containers, closing the loop on the original product. Many brands incorporate a significant percentage of rPET into their packaging to meet sustainability goals.
Beyond packaging, a substantial portion of rPET is converted into polyester fiber, used to create clothing like fleece jackets, carpets, and upholstery fabrics. Other applications include strapping materials, insulation, and thermoformed packaging for fresh produce. Utilizing rPET instead of new plastic significantly reduces energy consumption, with estimates suggesting a reduction of up to 79% in total energy use for new bottle production.