Advanced filament is key to 3D printing revolution

Polymaker CEO argues that better filament, and not necessarily better desktop machines, will unlock the disruptive potential of 3D printing.
Written by Greg Nichols, Contributing Writer on

An entrepreneur friend of mine likes to tell the story of the time he met a very rich man. Impressed by the guy's car, clothes, and companion, my friend wanted to know what the man did for a living. The rich man said he sold a product to Wal-Mart. My friend wanted to know what he sold -- clothes, electronics, housewares? The man dismissed all these with a chuckle and a wave. "No one gets rich that way," he said. "You know the boxes Wal-Mart uses to ship all that stuff? I make the glue that holds them together."

I thought about that story the other day during a phone call with Xiaofan Luo, founder of the Chinese company Polymaker, which makes filament for 3D printers.

Luo is an American-educated materials engineer with a PhD in polymers. Back in 2008, he and some fellow grad students were developing a new material that had promising applications in medical devices. The team figured that 3D printing -- then better known by the more general "rapid prototyping" -- would be an easy way for hospitals to manufacture customized one-off devices for patients, so their idea was to create a medical-grade material that was compatible with conventional 3D printers.

To their surprise, they found that none of the companies making 3D printers at the time allowed third-party printing material -- filament -- to be used in their machines.

"That was a big limitation of the technology," says Luo. "To me it was a little bit ridiculous, even. Fundamentally, 3D printing is a new way of processing materials, of converting them into objects. It's similar in that respect to injection molding or extrusion. No one could imagine buying an injection molder or extrusion machine and then being limited to only using the materials the manufacturer provides."

By 2012, with greater competition in 3D printing and a groundswell of designers clamoring for the ability to use multiple platforms in concert when making their prototypes, manufacturers started relaxing their thinking on proprietary filament. Luo started Polymaker in order to address what he saw as a glaring gap in the market.

"The machines are getting very good," says Luo, "but materials are the next big thing."

It's not hard to see his point. Though industrial designers and engineers can now swap filament between most desktop printers, the range of materials available to print with is still very narrow. That's led to severe limitations when it comes to creating objects.

Some of these limitations are related to functionality. Normally, engineers and industrial designers carefully select materials for their unique properties, such as conductivity, strength, or softness. But filament doesn't come in many flavors, so to speak -- at least, not yet. That means designers are working with a very limited palette.

Perhaps the biggest limitation right now, however, is geometry. There's a conception that 3D printers convert any digital design into an object, almost like magic. But there are currently significant constraints when it comes to designs that have overhanging parts. Filament emerges from a printer as a bead of viscous liquid, meaning it tends to distort unless printed on a reasonably flat surface.
A 3D-printed guitar (3D Printing Solutions, Australia)

The workaround has been to use a support material, which provides a temporary structure during printing that can later be removed. But the most common method for supporting a geometrically complex object is to design buttresses using the same printing filament used to make the object. That means the support structure must be cut away from the printed object, which is time consuming and leads to high failure rates. It also means curved surfaces are difficult or impossible to achieve.

There are water soluble support materials, but these tend to be very finicky and quickly absorb water from atmosphere, which renders them useless.

One of Polymaker's newest products, and a good illustration of how advanced filaments may be the missing component that allows 3D printing to finally fulfill its promise of radically altering how goods are manufactured and distributed in the marketplace, is a new kind of support material. The material is printed by the printer and adheres to PBA, a commonly used filament material, but only weakly. Once an object is printed and has hardened, the support can be peeled away easily.

"With PolySupport, what you can finally do is just click a button and print," says Luo. "You know you will get results, and you don't need to tweak models. It also just simply makes a lot of things that were unprintable now printable."

Polymaker now has 48 employees and operations in the U.S., Europe, and China. Earlier this year the company received $3M in Series A funding from Legend Star, the VC arm run by the holding company that owns Lenovo. The glue business may not be sexy, but it's absolutely essential to global commerce. If Luo's vision is on point, the same will soon be said about filament.

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