Corn to Cup: How Field Corn Becomes Plastic

From Illinois fields to everyday products, corn is helping create a new generation of plant-based plastics. 

What is corn plastic? 

Corn plastic, also known as Polylactic Acid or PLA, is a type of bioplastic made from field corn. Instead of relying on crude oils to create plastic, PLA starts with something grown right here in the Midwest. 

Manufacturers have turned to materials like PLA as they look for ways to reduce their environmental impact while still creating durable single-use products. 

While PLA can also be produced with sugarcane, sugar beet, and other raw materials, corn accounts for over 60% of all PLA production. This is due to its strong global supply, established refining chains, and lower conversion costs. 

Currently, the global PLA market is estimated at $2.01 billion. By 2030, it’s expected that the growing demand for sustainable bio-based plastics will grow this market to $4.51 billion. 

How does corn become a cup? 

PLA production relies on the process of fermentation and can be broken down into 5 easy steps: 

1. Grow and Harvest: Field corn is grown and harvested across Illinois. It contains starches, proteins fibers, and oil. 
2. Separate the Starch: Corn is milled to separate the starch from the rest of the kernel.
3. Starch to Sugar: Enzymes break down the starch into a simple sugar called dextrose. 
4. Fermentation: Last, microbes ferment the sugar into lactic acid, forming solid PLA pellets. 
5. Manufacture Products: PLA resin is molded into products like cups, straws, 3D printing filament, and packaging. 

This relatively simple process creates almost 500 thousand tons of PLA annually. With corn starch representing 60% of that, it’s estimated that 30 million bushels of field corn are used in PLA production every year. 

Why use corn-based plastics? 

PLA has several benefits that make it an appealing alternative to conventional plastic: 

• Made from corn, a renewable resource 
• Emits 68% fewer greenhouse gases 
• Requires 65% less energy to produce 
• Biodegradable and can break down in as little as 90 days with industrial composting 
• Non-toxic fumes when incinerated 
• FDA-approved and food safe 

Where do you see PLA in everyday life? 

PLA is found in cups, cutlery, take-out containers, and a variety of other single-use products. It’s also the most popular filament option for 3-D printed goods. 

If you want to see PLA in action or purchase corn plastic products, here are a few places to look: 

• Good Start Packaging 
• Green Paper Products 
• EcoProducts 
• Manubim -- Custom 3D Printing 
• American Filament -- 3D Printing Filament   

Sources:

• https://www.marketsandmarkets.com/ResearchInsight/polylactic-acid-pla-market.asp 
• https://prismaneconsulting.com/report-details/polylactic-acid-pla-market 
• https://www.credenceresearch.com/report/polylactic-acid-market