Mechanical and molecular recycling—Some things are just better together

Historically, “made with recycled content,” refers to materials and products made from mechanical recycling and also known as traditional recycling. Mechanical recycling typically processes two types of widely recycled plastics—PET and HDPE. These are the plastics marked with Resin Identification Code (RIC) 1 or 2—products like clear single-use water bottles, clear gallon milk jugs, etc. The mechanical recycling process includes collecting waste plastic from recycling bins, delivering to a recycling center, cleaning, chopping, then remelting and forming plastic pellets that will be used to make other products.

Mechanical recycling is a very effective, environmentally friendly process that should be used whenever possible.

However, mechanical recycling is generally unable to process the other five types of plastic—items like fast food containers, colored plastic bottles, plastic eyeglass frames, etc. These items have RICs 3 through 7 and typically end up in landfills or incinerators.

Mechanical recycling is useful, but it has limitations:

  • Requires clean sources of materials
  • Materials can only be mechanically recycled a finite number of times due to degradation, often resulting in reduced performance in key properties.
  • There are seven different types of plastics produced; mechanical recycling can only process two.
  • Many products made with recycled content eventually end up in the landfill due to downcycling. For example, a water-bottle cap can be recycled into a lipstick container. That lipstick container, if recycled, can be made into a pen; and the pen, if recycled, can be made into shoelace tips. At this point, the shoelace tips can’t be recycled again and often will end up in a landfill once the shoelaces are done being used.

Plastic recycling today

Mechanical recycling is designed to delay plastic from going to the landfill, but alone it is not enough. We need a solution to create products that improve our quality of life and keep them in use longer.

Through Eastman’s Advanced Circular Recycling technologies, also known as molecular recycling, we are creating value from waste. These technologies break down waste into its molecular building blocks so it can be reused over and over again—creating an infinite life span for materials that were previously destined to be discarded. It provides a powerful new tool in the fight against material waste, enabling us to reimagine and revolutionize materials.

Mechanical recycling

At Eastman, we are utilizing two different types of molecular recycling technologies—carbon renewal technology and polyester renew technology.

Carbon renewal technology (CRT) uses a broad mixture of plastic waste—in some instances items as diverse as mixed plastics, textiles, and carpet—and uses them as a material source. Then, that mixture of waste is converted back to small molecules and chemical building blocks that are used to make a broad range of new consumer products.

Polyester renewal technology (PRT) takes polyester plastics, such as soft drink bottles, carpet, or even polyester-based clothing, and unzips them back to their basic monomers. These monomers are then sent through a polymerization process to make final products.

Differences

Mechanical and molecular recycling are two very different approaches to recycling with clearly different benefits. We believe mechanical recycling should be leveraged whenever possible, as it is the most efficient and environmentally friendly recycling process in the materials space. However, we firmly believe it will be challenging to meet sustainability goals with mechanical recycling alone. More importantly, we can’t stop at these goals. We must pursue a 100% circular solution, and we must do it as economically as possible.

Advancing material technologies and circular solutions is central to Eastman’s commitment to deliver change right now.