
While companies in arenas ranging from jewelry to aerospace are now familiar with using 3D printing to fabricate parts and other objects, “3D printing textiles is a newer concept,” says Jack Forman, doctoral student at the Center for Bits and Atoms of the Tangible Media Group, Massachusetts Institute of Technology (MIT) in Cambridge, Mass.
“I certainly believe that there’s a future, but it takes some grappling with the realities of what 3D printers are currently capable of, which is constantly changing; what materials they can currently print with, which, again, is constantly an expanding library; and then what these specific textiles are designed for,” Forman says.

Stratasys has been using its PolyJet™ inkjet-based technology and 3D printers since 1998 to create products from prototypes to end products in multiple market sectors.
Zehavit Reisin, senior vice president of consumer solutions for materials business at Stratasys’ Rehovot, Israel, headquarters, says, “We thought, ‘OK, we’ve got this technology working for more than 25 years. What if we print directly on fabric?’” Instead of printing multiple layers of resins on a tray to create an object, Stratasys’ 3DFashion™ technology creates a mechanical adhesion between the printed polymers and the fabric fibers. The company prints on a variety of textiles, including denim, lace, net, wool and suede. The PolyJet machines print resins in cyan, magenta, yellow, black, white and translucent, allowing programming for a full color range. Tier-one suppliers to luxury fashion brands are already using Stratasys’ technology for 3D printing on items such as luxury handbags and shoes.

Applications
The current end user for 3D fashion products, Forman says, is a customer of those haute couture brands, based on high production costs. 3D printing, Reisin says, serves this segment’s business needs. “Fashion and luxury goods are probably the second-most wasteful market in the world, after oil and gas, and the need to minimize the waste is screaming out from every top brand we talk to,” she says.
As opposed to new luxury goods, with the development of a special tray that allows the ability to print directly onto a garment, the TechStyle™ D2G solution, Reisin says Stratasys can also offer a second life to existing garments. “You can come to a shop with your pair of jeans that you’ve had it with and give it a second life by decoration,” she says.
Or, says Forman, 3D printing can be used to expand or contract a structure without requiring the printing of an entire garment. He has 3D-printed a pleated, expandable pocket that he ironed onto a T-shirt. “It doesn’t require us to solve everything related to ‘Does this look and feel like a T-shirt?’ but it still allows us to augment with some interesting structures,” Forman says.

Pros and cons
Forman’s DefeXtiles 3D-printed fabric was a happy accident during an MIT course he was taking called “How to Make Anything.” While experimenting with a traditional 3D printer, he set it up to under-extrude polymer filament. When he removed his work from the printer and started stretching and bending it, “I realized that these are very interesting, fabric-like materials,” he says.
He also realized that rather than printing flat, directly onto the print bed, his technique of printing vertically allowed for curved, pleated and origami-like 3D-printed textiles. “I was using just traditional PLA [polylactic acid], which is traditionally a rigid material. But just by printing very thin structures, you’re able to turn what’s traditionally rigid material into something that’s very flexible and even stretchable, [which] almost has some elastic-like behaviors,” Forman says.

However, most 3D-printed textiles are still on the stiffer side, Forman says. The nature of 3D printing—layer by layer deposition of a filament—introduces small crack-like spaces with each layer. While the textiles can bend and form in some dimensions, stiff material such as PLA eventually will separate due to stress fractures from folding. Thermoplastic polyurethane is fully crushable but slow to print and more flexible than needed, Forman says.
“I think a way forward to get something that is soft, conformable, durable, is to find some hybrid, like an elastomer and a PLA material” that achieves both fast print speeds and durability, he says. In the meantime, Forman says, durability is an issue for 3D-printed fabrics. Washability is a concern, as hot water can immediately affect materials like PLA.
To comply with fashion industry standards and expectations, Reisin says, Stratasys developed dedicated VeroEco™ Flex acrylic-based photopolymer resins that are semi-flexible and less rigid, to provide a better feel and aesthetic.

Different responses from different fabrics
Textile machinery manufacturer Karl Mayer, headquartered in Obertshausen, Germany, has developed a 3D-printing desk with an integrated camera for positioning, which can scale the print area up from 1 by 2 meters (39 by 79 inches) to 138 inches. Using multiple printing heads within that area allows printing in more than one color. A moving belt produces free transport of the textiles for inline production at approximately 25–35 meters (82–115 feet) per hour.
Some of the challenges, says Michael Kieren, product manager of new textile technologies at Karl Mayer, come directly from the textiles themselves. Although precise positioning of the camera is important for printing patterns such as designs into jacquard or branding into various fabrics or flower designs created in lace, “The textile has its own life. It does whatever it wants to do,” he says.

Kieren says this might manifest in flexible fabrics with staining on the inside, curling at the edges, or patterned fabrics having a mismatch between right and left sides due to shrinkage or different runs in yarn. “This makes it very complicated,” he says. Experiments with printing directly on unfinished gray fabric yielded the knowledge that for elastic fabrics where it’s necessary to control the stretch, it’s better to use the inline printing option. “All other applications, it’s better that we use this printing desk as a roll-to-roll machine,” he says.
Different fabrics and different dyes also experience adhesion differently. In his company’s experience, he says 3D materials adhere better to other textiles than to polyester.
Karl Mayer, Kieren says, is developing a database to share its learnings, such as strategies for printing designs, proper distance between the printing nozzle and the textile, and determining viscosity of the extrusion.

The possibilities
When it comes to applications, Stratasys originally chose to focus its textile 3D printing efforts on clothing, bags, accessories and footwear, but the tech could be applied to theater costumes and more. Karl Mayer’s brand partners, Kieren says, have suggested things like using 3D printing to cover the portions of athletic garments that contain electronic sensors, to protect them from the deleterious effects of saltwater in sweat.
Embedding sensors into textiles via 3D printing has potential applications in the biomedical field, Forman says, suggesting that an external neuro-electrode apparatus could be replaced with a soft beanie hat, for example. He also thinks sensors embedded into clothing could change human/computer interaction, allowing things like rejecting a phone call or silencing a message through physical interaction.

Kieren says Karl Mayer has experimented with 4D printing golf shirts that give biofeedback meant to condition an athlete into repeating a particular swing and follow-through. The company has accomplished this by pre-stretching an elastic material into a particular tension, 3D printing on it and then printing into another dimension when the print is stiff. The stiffness or compression embedded into the fabric causes an athlete to meet resistance when trying to move in the wrong direction. It would also be possible, Kieren says, to develop a garment such as a jacket that would react to changes in heart rate and breathing.

Stratasys is using 3DFashion to provide shoulder-, neck- and hand-protection wearables for police and military markets as well as to move into other arenas. It remains heavily invested in fashion, where its 3D printing can be used for decorative applications such as two-sided designs and lenticular effects. The company also has integrated 3DFashion with other technologies by developing a TechStyle™ Fabric Alignment Station that allows accurate coordination between 2D patterns or embroidery and 3D designs.
Automotive interiors are another use case where 3D printing can integrate branding into the textiles. A potential for integrating functionality within automotive interiors, Kieren says, would be 3D-printing a silicon element into an original equipment manufacturer’s logo or creating an area where a smartphone could be situated, remain stationary and charge better within the vehicle.

“I believe that in the next years—and definitely with the recently released innovations that enable printing on a wide range of fabrics—we will see a ramp-up and shift from one-off products and small capsules to more than thousands of units of production,” Reisin says.
Karl Mayer currently is seeking potential manufacturing partners for the use of its printing head. As the company initiates trials, including determining the optimal printing materials for an application, products are likely three to five years away, Kieren says.

As for 3D printing of textiles themselves, that’s still mostly oriented toward a prototyping audience, with broader applications likely “a few more years out,” Forman says.
And the big picture of 3D printing in textiles? “I think this technology is unlimited,” Kieren says. “I think we are currently in the beginning of this application.”
Joanna Werch Takes is a writer and editor based in Minnesota.