Thermoplastics are a class of plastic polymer that turn to liquid when heated and re-solidify when cooled, a process made possible by simple bonds between polymers allowing the plastics to be re-melted and remolded repeatedly without losing structural integrity. Ultimately, products made with thermoplastics can be easily recycled without losing their original properties and reused to make new consumer goods. Consumer education is a critical part of ensuring recycling is an effective, efficient practice. Limited public understanding of recycling processes and the reasons as to why plastics are well-suited for reuse and reclamation mean the average consumer is unlikely to identify even the most commonly used and recycled plastics, despite both government and industry action to ensure that plastic products are appropriately recovered and recycled.
Though the technical name thermoplastics may not be familiar, materials like acrylic, nylon, polyvinyl chloride (PVC) and polypropylene are all types of thermoplastics that are used to make highly recyclable plastic bottles, food packaging and even athletic gear. In fact, thermoplastics make up 75% of plastic products worldwide, meaning the majority of global plastics are easily recyclable when provided with an appropriate disposal and processing infrastructure.
Thermoplastic products are made through extrusion—a process that melts plastic pellets into a liquid that is then passed through pipes into product molds, where it cools to take final shape. Post-consumer thermoplastics are easily recycled through the same process. In fact, they can even directly replace virgin plastics in production with little modification due to the simplicity of the process.
Unlike paper, which degrades during the recycling process and can only be recycled six times on average before the fibers are too short to bond into new paper, thermoplastics can be heated, reformed and reused countless times without quality degradation. The simple polymer bonds maintain structural integrity throughout processing, with no loss in quality or limit to reuse.
Additionally, thermoplastic extrusion recycling limits waste compared to metal recycling, which generates excess scrap. By piping liquid plastics into product-specific molds, there is minimal excess or waste, and scrap or pieces stuck in the extrusion tubes are easily processed into new products thanks to the material’s infinite recycling life.
In addition to their recyclability, thermoplastics are also a lightweight, durable material that is heat proof and impact-resistant, making it an ideal material across industries. On top of these benefits, the simplicity of thermoplastic production and ability to re-use product molds also means that thermoplastics are more affordable than alternatives like lumber or glass, and can be produced in higher volumes at a faster rate.
In the automotive industry, thermoplastic polyphenylene sulfide (PPS) has incredible dimensional stability, even compared to other plastics. As PPS retains its shape so well over time, the material is ideal for complex shapes like the components for automotive fuel systems and engine intake covers. Despite the complexity of different models, these parts are easily created in high volume set molds and can retain their shape for years, even in high-heat environments like car engines.
Within the medical industry, thermoplastics like polyvinyl chloride (PVC) are also used in a variety of applications. Rigid PVC is ideal for the creation of custom prosthetic sockets due to their durability. PVC can ensure an exact fit from a limb mold, and the low cost of production means that multiple iterations can be created, tested and modified to ensure a correct and comfortable fit prior to product finalization and use. Another type of PVC, flexible PVC, is frequently used as a safe replacement for rubber in materials like blood donation bags and medical tubing because of its sterility and durability.
Thermoplastics play a crucial role within the clean energy industry. Specifically, critical technologies for the energy transition are being developed with thermoplastics. While wind turbine blades are commonly made from steel, thermoplastic foams and composites are now being used to make lighter, more efficient turbine blades. Not only do lighter blades save resources because they require less fuel to transport than their heavy steel counterparts, but the lower overall weight also reduces drag on the turbines, so less energy is expended when the blades are moving, and more energy is stored for future use.
In March 2022, a Spanish subsidiary of GE Renewable Energy, LM Wind Power, built the world’s largest fully recyclable wind turbine blade from thermoplastic resins. The over 200-foot long, fully recyclable blade is now undergoing testing in Denmark. At the end of its useful life, the blade’s components will be dismantled and recycled into new material compounds for use in future blades. Current wind turbine blades made from fiberglass are not recyclable, creating significant waste that the energy industry is working to address.
Thermoplastics are a critical material across industries. It’s no surprise why this widely adaptable class of plastics is used in so many popular products, and its fully recyclable properties underscore its importance in a circular future.