Researchers Improve Processes for Creating PLA For 3D Printer Filament, Soon to Be ‘Cheaper & Greener’

3D printing with PLA already has a lot going for it with an environmentally-friendly bend and a host of benefits for uses in making. Now, that’s about to improve further–and significantly. Who wouldn’t be glad to hear that the impact will be positive on the wallet–and on Mother Earth?

As a common debate up for grabs and also often a consideration when buying equipment, ABS versus PLA can be a hot topic among 3D printing enthusiasts. Often a number of different factors are going to dictate your material usage, but PLA is well-known for and often more desirable due to its vegetable base. While you can’t take your failed print and throw it in the backyard compost pile with organic matter and last night’s kitchen salad scraps, it is possible to have it composted in commercial venues. Also beneficial due to elimination of warping issues, better printer speeds, lower layer heights, and even a sweeter smell that draws many, PLA is a favorite for many–and especially those who like to recycle. It helps out on the guilt factor a little as we continue to pile the Earth with trash in other ways on a daily basis.

What’s the downside? It’s costly to produce. While that sweet sugar smell might add a tantalizing aroma to the home or workshop, you pay for it. And nothing puts a cramp in the artistic style like a rapidly diminishing budget as product rolls off the printer–not to mention when something fails and has to be thrown out–recycling or not.

Today, some of the downsides of polylactic acid may be about to change. According to researchers at the KU Leuven Centre for Surface Chemistry and Catalysis, they set out to help integrate the wonders of PLA further into the world by finding a way to produce it more simply and cheaply–and really make it waste-free. While this is good news for many of the industries that make use of PLA, it could be a real boon to the 3D printing industry, on all levels.

With the challenge in meeting the number of complex steps in forming and re-forming the thermoplastic that incur higher production costs and cause waste along the way (not often considered in marketing), the researchers found a work-around with a new chemical process that concerns manipulating a mineral known as zeolite.

“First, lactic acid is fed into a reactor and converted into a type of pre-plastic under high temperature and in a vacuum,” Professor Bert Sels explains. “This is an expensive process. The pre-plastic, a low-quality plastic, is then broken down into building blocks for PLA. In other words, you are first producing an inferior plastic before you end up with a high-quality plastic. And even though PLA is considered a green plastic, the various intermediary steps in the production process still require metals and produce waste.”

The researchers have just released their findings in ‘Shape-selective Zeolite Catalysis for Bioplastics Production,’ published in Science. Authored by Michiel Dusselier, Pieter Van Wouwe, Annelies Dewaele, Pierre A. Jacobs, and Bert F. Sels, the bottom line is that the process they’ve discovered could be a real gamer-changer in the 3D printing industry, to assess it from one highly relevant, progressive angle. They fully expect their ideas to have an impact for industry participants who want to overcome the expense of making PLA so that the benefits can be more fully expanded.

“We have applied a petrochemical concept to biomass,”says postdoctoral researcher Michiel Dusselier. “We speed up and guide the chemical process in the reactor with a zeolite as a catalyst. Zeolites are porous minerals. By selecting a specific type on the basis of its pore shape, we were able to convert lactic acid directly into the building blocks for PLA without making the larger by-products that do not fit into the zeolite pores. Our new method has several advantages compared to the traditional technique: we produce more PLA with less waste and without using metals. In addition, the production process is cheaper, because we can skip a step.”

The scientists constructed a general scientific setup to gauge catalytic reactions. The distillation setup, simple but effective, possessed both a condenser and a phase-separator. This facilitated water removal and thus allowed them to perform the required measurements.

 “… it is possible to achieve accurate results for reactive distillation reactions where water needs to be continuously removed at a scale as small as 10 mL of reaction volume. This unit allows to measure reproducible catalyst behavior, solvent and substrate screening, as well as kinetic behavior. Setups scaled-up to 50 mL in volume (slightly modified) were producing identical results,” stated the researchers.

For many industries, PLA is not going to be a major player in replacing petroleum products; however, for the 3D printing industry, this new process in creating the thermoplastic could have a huge effect on the filament industry as manufacturers learn to cut out previous steps that add to the budget and then present extraneous waste issues.

“The KU Leuven patent on our discovery was recently sold to a chemical company that intends to apply the production process on an industrial scale,” states Professor Sels. “Of course, PLA will never fully replace petroleum-based plastics. For one thing, some objects, such as toilet drain pipes, are not meant to be biodegradable. And it is not our intention to promote disposable plastic. But products made of PLA can now become cheaper and greener. Our method is a great example of how the chemical industry and biotechnology can join forces.”

While many new changes and improvements occur within the confines of the 3D printing industry on what seems to be a daily basis, the refinement of these chemical processes is larger than just offering better prices and a purer product for the makers of world, but with the advent of greener, greater affordability, that offers substantially more opportunity for innovation.

What do you think of this discovery regarding PLA? Would greater affordability and an even more eco-friendly image cause you to use it more? Discuss in the Cheaper & Greener 3D Printing PLA Filament forum thread over at 3DPB.com.

Zeolite, the catalyst being used to speed up making PLA