3D Printing with Bioplastics: Engineering Biodegradable PHA Blends

Jackie Anderson offers a review regarding one of the most critical 3D printing topics today: materials. As innovation continues to grow, so do the options regarding software, hardware, and different types of plastics (along with many other alternatives today).

In ‘Engineering Biodegradable PHA Blends,’ Anderson explores issues with plastic waste, and the need to use more environmentally friendly materials as 3D printing filaments.

While other plastics such as acrylonitrile butadiene styrene (ABS) are often used in 3D printing, bioplastics like polylactic acid (PLA) are popular due to their ability to biodegrade, but still, there are other materials superior in that area; in fact, previous research has shown that thin films of other bioplastics like polyhydroxyalkanoates (PHA) may degrade in as little as 1.2 to 2.4 months. This is promising in eliminating the amount of waste that could emerge from 3D printing discards, with Anderson reminding us that plastics can take ‘hundreds to thousands of years to degrade,’ causing harm to every living creature.

“Plastic is a toxic pollutant that causes damage on a wide scale to many different species and environments, and it is necessary that solutions are found to reduce this impact,” states Anderson.

Bioplastics are used in so many different projects today, from marine applications to medical implants to manufacturing. Produced from vegetables, food by-products, or micro-organisms, bioplastics are preferable to oil-based printing materials, environmentally. They are also conventionally used in making items like packaging, cutlery, straws, and even fishing net.

In using man-made plastics like PLA, biodegradability is a bonus, but printed parts can take years to break down:

“This makes it an undesirable material for products that require high rates of biodegradation,” states Anderson.

PHA is not as well-known overall, and especially not with novice users. This material biodegrades faster but is more expensive, not as accessible for consumers, and Anderson points out that it is often challenging to use on a larger scale. PHA also presents drawbacks in comparison to other bioplastics, offering less strength, less flexibility, and inferior melting properties. It can, however, be beneficial when added to other materials like PLA.

“There are other similar PHA blends that have been designed for similar purposes and have also shown great potential for commercial use, yet more research needs to be done on different PHA blends to expand this potential,” states Anderson.

Algae-based biopolymers, while still considered more of a novel material, are like PHA as they are produced naturally and biodegrade easily. Along with 3D printing materials, algae plastics are also used to make films, cutlery, and plastic bags.

“Algae plastic is just one of the many new bioplastics being developed and researched to help reduce plastic pollution. These products are beginning to be marketed more frequently and will help minimize plastic pollution if used on large scales to replace oil-based plastics,” explains Anderson.

Still, PLA is a favorite within the 3D printing industry, due to accessibility, affordability, efficiency in production, and some semblance of biodegradability:

“If PLA materials were to be discarded into landfills or abandoned in the environment, they would take several years to degrade, causing pollution like that of regular plastics,” states Anderson.

“This is deceiving because companies claim that PLA can degrade in about 40-90 days, but this is not the case if the materials are not in a controlled lab setting (PLA, 2019). PLA can only degrade efficiently in specific industrial composting conditions with temperatures at or above 55-70 degrees.”

Using PHA and PLA to create a composite for greater strength and biodegradability could be a good solution, allowing users the best of both worlds.

“While these bioplastics each have their own negative qualities, they can be blended together in different ratios to form a desirable new plastic with the beneficial qualities of each of them,” concluded Anderson.

“These new blends could be used for a wide range of applications, from food packaging to 3D printing filaments. Bioplastics cannot solve the plastic waste crisis altogether, but they can limit the future pollution caused by plastic use and help reduce the damage that humans have caused.”

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[Source / Images: ‘Engineering Biodegradable PHA Blends’]