PHA: colorFabb’s Fully Biodegradable Alternative to PLA and PETG for 3D Printing

By on January 30th, 2024 in interview, news

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Ruud Rouleaux examining a vase 3D printed in PHA material [Source: colorFabb]

Here’s everything you need to know about an up-and-coming 3D print material that’s entirely sustainable: PHA.

We spoke with Ruud Rouleaux of colorFabb, which has been doing considerable research on this unusual material. PHA is said to print very well, and yet be entirely biodegradable. That’s a critical factor as the world begins to recognize the massive microplastic pollution problem.

Fabbaloo: Your company, colorFabb, produces filament in PHA material, which has some interesting features we’d like to explore. What exactly is PHA? Is it a fossil-derived material?

Ruud Rouleaux: PHA is a relatively unknown natural material, and we’d like to change that. In essence it’s a natural occurring polyester, which is even present in one’s body.

The short description would be: Polyhydroxyalkanoates or PHAs are polyesters produced in nature by numerous microorganisms, including through bacterial fermentation of sugars or lipids.

PHA chemistry [Source: colorFabb]

When produced by bacteria they serve as both a source of energy and as a carbon store. In laymen’s terms, the fat of micro-organisms, which can be extracted as a powder, in this case a polymer, or to be more specific a polyester.

PHA is a family of polyester building blocks, that can be combined to achieve specific mechanical and thermal properties.

Fabbaloo: I’ve heard that PHA addresses a number of long-term safety concerns, particularly around biodegradability and lack of microplastic pollution. Could you explain how this is accomplished?

Ruud Rouleaux: Indeed, PHA is readily biodegradable in many environments including soil and marine environments, as it is a nutrient that micro-organisms can digest (as a carbon foodsource).

Also, smaller parts (labelled microplastics or nanoplastics) will be digested by micro-organisms in due time, instead of lingering as pollutants like petrochemical microplastics.

PHA decomposition in seawater [Source: colorFabb]

The picture above clearly shows how micro-organisms slowly have consumed a tensile bar in seawater (outside>in).

Fabbaloo: Does the decomposition actually work in practice? What happens to discarded PHA prints in typical landfill scenarios?

Ruud Rouleaux: Bacteria use PHA as food. The process can be explained (simplified); Bacteria will nest and multiply on the surface(s) of the product and segregate enzymes that dissolve PHA in such a manner that the bacteria can digest it. This happens layer by layer (surface erosion).

Depending on variables like temperature, moisture, concentration of micro-organisms this happens at various speeds. In garden compost, landfill or industrial compost this will happen rather fast (weeks <> months).

PHA decomposition [Source: colorFabb]

Our friend Stephan Hermann from CNC Kitchen did some working comparing PHA (allPHA by colorFabb) with PLA grades in his garden composter, demonstrating the rapid degradation of PHA in practical conditions (weeks).

Fabbaloo: Is there a danger of prints decomposing prematurely, perhaps when you are still using them?

Ruud Rouleaux: Not really, you need continuous exposure to micro-organisms in humid conditions to start the degradation. If used in a dry environment PHA will not start to decompose pre-maturely.

Fabbaloo: How well does PHA print? Does it warp? What strength can it offer? Could you compare it to PLA and PETG as a commonly used 3D print material?

Ruud Rouleaux: PHA is a semi-crystalline material, which means compared to PLA or PETG there will be more volumetric shrinkage and thus a tendency to show warpage. However, an advantage is that the crystallization process is rather slow and with the correct degree of cooling very well controllable / manageable.

PHA strength analysis [Source: colorFabb]

The big benefit of PHA formulations is that they can mimic of broad range of mechanical properties matching both PLA and PETG but also offer flexible and tough variants, while maintaining a HDT well above PLA and matching PETG.

Fabbaloo: Often new materials have quite constrained options for colors and other features. What scope of PHA products does colorFabb currently offer? Do you offer fiber-reinforced versions?

Ruud Rouleaux: Colors are available, however, to keep things simple we offered black, white and natural now. Natural colors and fiber reinforced grades have been developed, to be released in due time after more wider market acceptance.

Fabbaloo: Is PHA expensive? Is there a price premium? Would the price be lower if more 3D printer operators used PHA?

Ruud Rouleaux: PHA as a raw material is roughly twice the price of PLA. We aim to keep the filament pricing close to premium PLA to bridge the gap.

Decorative 3D printed item made in PHA [Source: colorFabb]

Since PHA is not a commodity yet, with only few producers worldwide, pricing would be lower if we’d see more producers scaling up over the next years. Luckily, the signs are good that this will be the case, since various markets have started to adapt to new legislations, pushing PHA to become more mainstream and thus allowing beneficial pricing.

Fabbaloo: What do you think would it take to convert individuals to switch from PLA/PETG to PHA?

Ruud Rouleaux: First of all: Creating awareness is key. Tell the story, explain the Why / How / What. This is my personal mission. It has taken PLA several years to grow into its current benchmark status in Desktop DIY 3D Printing. I assume PHA can follow the same path.

Raising attention and understanding sustainability in 3D Printing is subject to many trade-offs. In most cases end-of-life is not considered. Produce > Use > Discard, but what happens after that?

PHA will not be a long term polluter, it’s part of a natural cycle can be recycled, re-used, or composted.

Fabbaloo: What would it take to convert the desktop 3D printing industry as a whole to switch from mostly PLA/PETG to mostly PHA?

Ruud Rouleaux: It’s our aim to provide a drop-in PHA filament for various synthetic of petrochemical counterparts, with at least the same printability. In practice this will mean finding the sweet spot between hardware / software and the 3D Printing material.

PHA vases 3D printed on Bambu Lab equipment [Source: colorFabb]

Recently we have been running various formulation on Bambu Lab printers, producing very satisfying results in terms of printability, but also appealing surface appearance and fantastic haptics.

For now, we’ll need to support 3D Printing enthusiasts with their customer journey when they start working with PHA. Customers who appreciate the materials characteristics and make conscious choices.

In short; work with first adapters, allowing a broader introduction of PHA in the 3D Printing landscape.

Fabbaloo: What has driven you and colorFabb to produce this eco-friendly material?

Ruud Rouleaux: Material innovation is in our DNA. ColorFabb is not a producer of bulk filaments and mainstream materials only. Already in our start-up phase in 2010, PHA was one of the first ingredients used to produce a tough PLA filament, which we still produce today.

The questions from our customer for more circular materials have led to further push the envelope of what we did before. Especially during the last 3 years, new PHA producers have started producing different PHA building blocks, allowing improved processability and functionality. Here we strive to accomplish our position as a 3D Printing pioneering company and thrive forward.

Furthermore, the public awareness regarding plastics pollution and over-consumption keeps growing daily. LOHAS customers (Lifestyles of Health and Sustainability), are typically the first to question the status quo and adapt.

Fabbaloo: Finally, are you working on any secret PHA formulations that we may see in the future?

Ruud Rouleaux: We’ve been working on various new developments and have developed 300+ formulation for vary applications, some of them can be used in 3D Printing as well. Since we can mimic most properties it’s up to the various value streams for these properties should look like. On short term, softer, more elastic PHA grades are an obvious choice.

Via colorFabb

By Kerry Stevenson

Kerry Stevenson, aka "General Fabb" has written over 8,000 stories on 3D printing at Fabbaloo since he launched the venture in 2007, with an intention to promote and grow the incredible technology of 3D printing across the world. So far, it seems to be working!

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