Footwear has been a craft around for centuries. Beginning by handcrafted shoes, to the first shoe stitching machine invented by Lyman Blake in 1856. Manufacturing in the footwear industry has continued to expand and improve.
As in many other industries, 3D printing began as a prototyping tool. Silvia Fado, CEO and Head Footwear designer, explains that 3D printing in the shoe industry has mainly been “prototyping to show to the customers the volume before spending money in mold making, which is very time and cost-effective.”
The footwear industry is massive (in 2018 over $106 billion globally was generated from footwear alone) where a variety of materials and products are made in men, women, and children’s sizes. Shoes can even be specialized for use such as athletic shoes, cleats, snowboard boots, to dress shoes and more– there are shoes for every occasion and need.
While a majority of brands in the industry are using traditional methods, sportswear companies like Adidas, Nike, Under Armor, and Reebok are jumping into the growing process of 3D printing.
Adidas and 3D Printing
The front runner of using 3D printing in the industry is Adidas. Currently, they are one of the few brands bringing 3D printing technology to mass production. The brand is the only one to date that has managed to ramp up production of 3D printed shoes despite 3D printing going in and out of the market for years.
In 2015 Adidas teamed up with Parley for the Oceans to create a recycled 3D printed sneaker concept. The design consisted of an upper made from “ocean plastic content” and a 3D printed midsole made from recycled polyester and fishing nets.
Adidas has released 3D printed soles since late 2016. The Adidas FutureCraft Runnerfeatured a mix of mesh and knit over a 3D printed sole. The shoe developed on the Speedfactory concept that allowed shoes to be made in a matter of hours, instead of months.
The AlphaEdge 4D, released in November 2018, has a unique mint green sole that is produced with Carbon technology. The $300 shoe is Adidas’ most ambitious sole to date.
“What started out as a conceptual FUTURECRAFT innovation, has not only allowed us to completely re-think our manufacturing processes but to create a data-driven experience that breaks new ground in performance capability and comfort,” said Klaus Rolshoven, Director of Future Design at Adidas.
Adidas uses Carbon’s Digital Light Synthesis (DLS) technology (a type of layerless photopolymerization). Carbon’s process uses a digital light project, oxygen-permeable optics, and programmable liquid resins to create their high-performance and durable polymeric products. As an industry leader, Adidas is using the DLS process and sport-science expertise to create custom shoes that provide each customer with a unique and ultimate performance.
Having produced over 100,000 pairs of shoes with the 3D printed technology, Adidas has confirmed they have enough printers to make one million pairs of their 3D printed sneakers in the coming years.
GQ wrote in 2016, leading up to the 2016 FutureCraft Runner release, that “In a few years, Adidas hopes that one will be able to walk into a store, get your foot scanned, and exist with a custom pair of sneakers that have been 3D printed for your specific needs.”
“We have a really aggressive plan to scale this,” stated James Carnes, Vice President of Strategy Creation at Adidas, last year. He continues; “We are scaling a production. The plan will put us as the (world’s) biggest producer of 3D printed products.”
Adidas is clearly leading the market in the 3D printing aspects at the moment. However, as big as Adidas is and how hard they are pushing the technology they have yet to send out a fully 3D printed shoe. And there are very few doing so at the moment.
Nike’s Just Doing It
Nike was among the first companies to use 3D printing for high-performance product development. The brand used the technology for quick iterations of functional parts.
Highest profile project Nike produced was Vapor Laser Talon. This shoe was the first 3D printed football cleats designed to provide optimal traction on turns and help athletes maintain their “drive stance” longer. This project didn’t make it into production however it was followed by the Nike Vapor High Agility cleat.
3D printing allowed the Nike team to test, iterate, and create shapes not possible with the traditional manufacturing process, helping push the limits of innovation faster.
Currently, Nike is experimenting with the labour-intensive production of uppers. The Nike Flyprint is the first 3D printed textile upper in performance footwear. The combination of Nike Hyperfuse, Flywire, and Flyknit are meant to achieve an unimaginable performance solution.
The process to print the Flyprint uppers begins by using captured athlete data that is computed to affirm the ideal composition of materials. This information is used to produce the textile that will be used which can be specific to athlete or function if needed.
The Flyprint uppers are produced through solid deposit modelling (SDM). In this process a TPU filament is unwound from a coil, melted, and laid down in layers.
The benefit that 3D textiles have created is the increased dynamism made possible by adding interconnection between warp and weft. The nature of the Flyprint textile allows it to be fused together unlike traditional knit and woven textile that creates a frictional resistance between interlaced sections. This allows the Flyprint material to have a greater potential for precision-turned containment along with being lighter and more breathable than previous textiles used by Nike.
Design time has increased, allowing prototyping to be 16-times quicker than previous manufacturing methods. 3D printing also allows rapid iteration allowing testing and revision cycle times are being trimmed significantly. The Flyprint material can also be adjusted locally, keeping the global construction preserved.
The Flyprint textile can also be seamlessly bonded to Flyknit yarn thermally eliminating the need for glue or stitching. This allows Flyprint to provide the greatest benefit to the athlete in the shortest amount of time.
The Flyprint uppers are designed for the world’s fastest distance runners to run their fastest. The first articulation of the shoe is the Nike Zoom Vaporfly Elite Flyprint shoe, created for Eliud Kipchoge and is driven by his feedback. Following the 2017 Berlin Marathon and rapid-fire prototyping, the latest upper improves the Vaporfly Elite and makes it11g lighter than Kipchoge’s original pair.