How are Nurdles Made?

Nurdles are used in the production of a wide variety of products, from plastic grocery bags to plastic car parts. Their tiny pellet shape allows them to be shipped in bulk to companies all across the globe. Small size is also beneficial during the manufacturing process, as nurdles will melt evenly before being molded into common plastic products. But how is each individual nurdle made?

The production of nurdles starts with the extraction of either oil or natural gas from the earth. Once extracted, both crude oil and natural gas are shipped to factories, where they will undergo a refinement process. At the factory, natural gas is separated into methane and ethane. Crude oil is boiled and sent to a furnace, where it is separated into different groups of chemicals. One of those groups is Naphtha, which contains both ethane and propene.

Next, a process called cracking will occur. Before ethane and propene can be used to create plastic, they must first be broken down from their original state into smaller units. Steam cracking is one way to do this. At a cracker plant, both high pressure and heat are used to break molecular bonds, creating smaller molecules (monomers). Ethane is turned into ethylene and propene becomes propylene. A process called polymerization is next, where long, repeating chains known as polymers are created from these individual monomers. It is during this stage that ethylene becomes polyethylene and propylene becomes polypropylene. You may recognize these names, as nurdles found along the Gulf Coast are typically made of either polyethylene or polypropylene.

Finally, these products make their way to a chamber where antioxidants and stabilizers can be added. Using an extruder machine, long strings of plastic are created and then chopped into smaller pellet pieces, or nurdles. These nurdles are then sent to manufacturers, where the production of consumer plastic products begins.


About the author: Lisa Scobel is a graduate student at the University of Wisconsin-Madison where she is pursuing a master’s in Environmental Conservation. A native of the Gulf Coast, Lisa is devoted to protecting coastal ecosystems and is passionate about reducing plastic pollution. Currently, Lisa is focused on expanding Nurdle Patrol by generating new partnerships and promoting data collection efforts.