The Basics of Bioplastics

Mar 29, 2018

It’s no secret: Plastics are a major threat to our environment. The United States alone generates over 30 million tons of plastic waste each year, with only 10% of that figure being recycled. The rest is piled into landfills or left to scatter across the globe, where it can take more than 500 years to break down. Every piece of plastic made within the last century is still present somewhere on Earth—and that’s a big problem.

compostable single-use coffee pod

UrthPact produces compostable plastic rings for single-use coffee pods.

The development of biobased plastics, or bioplastics, has provided humanity with a more eco-friendly alternative for the production of packaging and single-use items. The industry is steadily growing; market experts predict global bioplastic production capacity will increase from about 2.05 million tons globally in 2017 to approximately 2.44 million tons in 2022. In theory, bioplastics could replace any disposable item made from plastic, such as cutlery, packaging, and straws.

There is currently a wide range of bioplastic types with specific end-of-life options for each variety. Some biobased plastics can be composted, while others must be recycled. Some are “biodegradable” while others break down almost as slowly as traditional plastics. Understanding which biobased material is best for your product can be confusing. So we’ve put together this guide to help you learn the basics of  bioplastics.

What Are Bioplastics?

By definition, the term bioplastic can be applied to any plastic material that is primarily derived from renewable organic materials, such as corn starch. Other biomass sources include milk, tapioca, and vegetable fats. Unlike conventional plastics—which are made through the distillation and polymerization of non-renewable petroleum reserves—bioplastics present us with ecological advantages that can help reduce pollution of natural ecosystems and shrink our energy footprint.

Types of Bioplastics

When we refer to bioplastics, we’re addressing a large category of biobased polymers with a variety of unique attributes and applications. The list is always expanding as new materials are discovered. The most common bio-based plastics include:

  • Starch-Based Bioplastics: Simple bioplastic derived from corn starch. They are often mixed with biodegradable polyesters.
  • Cellulose-Based Bioplastics: Produced using cellulose esters and cellulose derivatives.
  • Protein-Based Bioplastics: Produced using protein sources such as wheat gluten, casein, and milk.
  • Aliphatic Polyesters: A collection of biobased polyesters including PHB (poly-3-hydroxybutyrate), PHA (polyhydroxyalkanoates), PHV (polyhydroxyvalerate), polyhydroxyhexanoate PHH, PLA (polylactic acid), polyamide 11 (PA11). They are all more or less sensitive to hydrolytic degradation and can be mixed with other compounds.
  • Organic Polyethylene: Polyethylene that has been produced from the fermentation of raw agricultural materials like sugar cane and corn, rather than fossil fuels.

Are All Bioplastics Compostable?

It seems like the answer to this question should be a resounding “Yes!” After all, it would be easy to assume that anything “biobased” is inherently compostable. However, this is simply not the case.

The term biodegrade refers to the process by which microbes break down a material under suitable conditions. Technically speaking, all materials are degradable but we typically only refer to those that degrade within a relatively short period of time (less than a year) as “biodegradable”. Because of this, not all bioplastics are considered biodegradable. In fact, bioplastics fall within a few different categories based on their applicable end-of-life solution.

  • Degradable: All plastics, including traditional petroleum-based plastics, are technically degradable. Given the right amount of time and environmental conditions, they will break down into tiny fragments. However, the materials used to make traditional plastics will never fully return to a “natural” state and will continue to pollute the environment with chemical compounds.
  • Biodegradable: Unfortunately, the term biodegradable has proven to be problematic because it often lacks clear information about the process requirements and timeframe required for biodegradation. In fact, to prevent consumers from being misled, California actually banned the use of the word biodegradable for any plastics sold within the state. Bioplastics that are considered “biodegradable” can be broken down by microorganisms such as bacteria, fungi, and algae into water, carbon dioxide, methane, biomass, and inorganic compounds. For practical purposes, bioplastics that can be completely broken down within a few months are considered biodegradable. Bioplastics that biodegrade more slowly (requiring up to a few years to be broken down) are referred to as “durable.”
  • Compostable: Compostable bioplastics can be broken down by microorganisms into nutrient-rich biomass in as little as three months and leave behind no toxins or residue. Some compostable bioplastics require high temperatures to decompose and must be returned to commercial composting facilities, while others can be composted in home gardens. Polylactic acid (PLA) is a compostable, injection-molded bioplastic that is quickly replacing petroleum-based polymers for the production of food packaging and single-use items because it can be easily composted. PLA also produces 70% fewer greenhouse gases when it degrades in landfills. To be considered compostable, bioplastics must meet the ASTM D6400 standard for compostability.

Where Are Bioplastics Currently Being Used?

Bioplastics might sound like a new-age concept, but in fact they have existed for one hundred years, at least. The Ford Model T, for example,  was produced using parts made from corn oil and soybean oil. As the problems surrounding petroleum-based plastics have become more apparent, bioplastics are more frequently used to make food containers, grocery bags, disposable cutlery, packaging, and more. PLA in particular has been used for a wide array of applications, including plastic films, bottles, medical devices, and shrink wrap. It has also been used for specialized applications in 3D printing. Many major companies—including Coca-Cola, PepsiCo., Heinz, Ford, Mercedes, and Toyota—have adopted bioplastics in their packaging materials.

How Can I Make My Products More Eco-Friendly?

At UrthPact, our goal is to help our customers produce eco-friendly products that won’t contribute to the global plastic problem. We specialize in injection-molded bioplastics, made in the USA, that can be easily composted by consumers. It is our mission to create positive contributions to an upward trend in environmentally friendly product use and waste management.

According to the EPA, the amount of waste diverted from landfills through proper composting methods has quadrupled since 1990. Producing single-use products from compostable bioplastics will bring that number even higher. For example, industrial food composting sites have to diligently screen food debris for petroleum-based plastic cutlery. Compostable cutlery would eliminate this problem. In addition, the production of compostable bioplastics requires one-third of the energy required to make petroleum-based plastics.

Compostable bioplastics have the potential to help solve the environmental issues surrounding our love of single-use plastic products. To find out more about how UrthPact can help you make the change to eco-friendly bioplastics, contact us today.


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