Which Performance Plastic Materials are Recyclable?
Many performance plastic materials are recyclable, and advancements in recycling technology have made it easier to process them. Over the last 50 years, plastic disposal has grown significantly, but since the mid-1990s, recycling has become more advanced with new technologies and increased awareness. Curbside containers and designated recycling stations have vastly improved disposal methods, leading to plastics being reused more often, saving money, energy, and helping the environment. This shift reduces litter and promotes a sustainable approach to plastic materials.
Some of the main plastics which can be recyclable are:
Polyester or PET carries the number 1 symbol. This plastic is primarily used for soft drink bottles. It is the easiest to recycle plastic and can be reground and reused time and time again.
The plastic with the number 2 symbol on it is HDPE which is a plastic primarily used for grocery bags, milk jugs and laundry detergent bottles.
PVC has the number 3 symbol and is used for pipes, fences and non-food containers.
LDPE is number 4 and is used for tubing, caps, rings and shrink wrap (coffee can lids).
Polypropylene has the number 5 symbol and its uses are for automotive parts, food containers and dishware.
Polystyrene is number 6 and is used for food containers and cups (including Styrofoam).
7 is other material such as Acrylic, fiberglass and Polycarbonate. These plastics are used for lenses, glasses and shields.
ABS is the number 9 symbol and is used in automotive, model building and molded parts.
What are the challenges in plastic recycling, including the role of the resin identification system and non-recyclable thermosets?
The biggest problem with performance plastic material recycling is that it needs to be meticulously sorted, which is why the resin identification coding system was implemented in 1988 to improve efficiency. Many schools and organizations work to collect and recycle materials, including plastics and aluminum cans, contributing to these efforts. The resin identification system, where the number helps name the plastic, has greatly improved how plastics are handled and sorted. However, some plastics, known as thermosets, cannot be recycled because they cannot return to their original form due to their chemical makeup and often contain additives or fillers. Phenolic, an early example, is used for electrical and mechanical purposes. Unlike thermoplastics which can be formed and returned to their original shape, thermosets decompose before melting when heated. These thermoset materials often replace more expensive alternatives, lasting significantly longer and reducing natural resource usage and carbon footprint, as seen with Nylon bushings replacing bronze in ships, offering dramatic savings.
There are, however, some plastics that cannot be recycled. These plastics are called thermosets, which are plastics that cannot return to their original form. The best example of this type of plastic is Phenolic which was the first commercially available plastic back in 1907, and was originally called Bakelite. It is primarily used for electrical and mechanical purposes. Unlike thermoplastics which can be formed and returned to their original shape, thermosets cannot due to their chemical makeup and they frequently have additives or fillers. Thermosets form above the melting temperature so when they are heated, the decomposition temperature is reached before the melt point.
Many of these thermoset materials replace other, much more expensive materials, and generally out last the former material by as much as 20 times. In practice, these material reduce the usage of natural resources and the ‘carbon footprint’ used to produce the items. One such material is the Nylon bushings used in large ships. The Nylon replaces a large Bronze bushing that used to be replaced once a year, and required the ship be put into dry dock to remove and replace the bushing. The new Nylon bushings out perform the bronze, and will last over 12 times longer. Dramatic savings in materials, casting new bronze bushing and the loss of sailing time of these ships.
How have recycling improvements impacted performance plastic materials, including reprocessed grades?
Recycling improvements over the last 30 years have made the process much more efficient for performance plastic materials. These advancements have led to better care in preventing litter and more accessible recycling programs. Plastics manufacturers frequently reuse and recycle materials during production, resulting in many performance plastic materials being available as ‘reprocessed’ or ‘commercial grade’ materials. This means they contain a percentage of material that has been processed before, unlike ‘virgin resin’ which is material sent through manufacturing for the first time. Any subsequent processing leads to the material being referred to as reprocessed. For more information on plastic recycling, you can find resources here or contact us at 866-832-9315 for specific material questions.
Want more information on the recycling of plastics, click here for recycling information. You may also contact us if you have a specific material question at: 866-832-9315, we are happy to assist.
