The Science of 3D Print-Knit Clothing
3D Print-Knit is a form of 3D Printing specifically for fabrics that is similar in process to the 3D printing that has grown in popularity over the last decade. It’s a digitally controlled additive manufacturing technique that enables rapid prototyping, small runs, and on-demand manufacturing. With the rise of various 3D printing technologies that have revolutionized the development of hard goods, we’ve been working with similar opportunities for printing “soft goods” like clothing. At Ministry of Supply, the union of printing and clothing came to life three years ago when Shima Seiki, the world’s leader in digitally-controlled knit manufacturing approached us with new manufacturing techniques that present impressive advancements over traditional clothing production.
Nimble Design
One of the biggest benefits of 3D printing is the ability to rapid prototype. Reducing the gap between design and product limits the opportunity for errors and reduces time spent sampling. Traditional prototyping is a messy, slow process. It involves a constant back and forth of physical goods between designer and manufacturer and long lead times. 3D printing, on the other hand, allows for a 3D model on a computer to become a wearable garment in a matter of hours, rather than weeks. This process allowed us to bring the designs for 3D Print-Knit Sweater Dress from sketch to production in just over a month.
Knitting Robots
When most of us think of 3D Printing, we picture MakerBots creating small plastic objects. In fact, 3D Printing is an umbrella concept. Under that umbrella is 3D Print-Knit, made possible by the Shima Seiki Mach2XS machine. Unlike a MakerBot, which can sit on a desk, this 3,000-pound computerized flatbed knitting machine is literally a piece of heavy machinery. It works by robotically manipulating over 4,000 needles, and allows us to create an entire garment in one piece.
Each 1/15th-inch needle creates a knot in a strand of yarn. These knots act like pixels on a computer monitor. Instead of brightness and color on a screen, the Shima Seiki system controls each knot’s color, material, and tension. Unlike 3D printed hard goods, which are weakest at the intersection between layers, 3D Print-Knit is incredibly strong between layers because each row of knots is physically intertwined with the layers before and after it. This interface results in strong, unified products. The upshot? 3D Print-Knit can be used for manufacturing durable consumer-ready products, not just prototypes.
Material Benefits
Rapid Prototype to Manufacturing: The primary benefit of 3D Print-Knit is that we can design a garment, print a prototype and fit it, all in a day. We have found that product quality correlates with number of prototypes because every iteration is an opportunity for improvement.
Zero Waste: Because 3D Print-Knit is an additive manufacturing process, it uses only the material that is needed and minimal support material compared to traditional cut & sew. In turn, it saves about 35% of material that would otherwise be scrapped.
Durability: Seams are the most common failure point for a garment, and the reduction of seams and linking, in many cases to zero increases the durability of the garment.
Garments with no Restrictions
With 3D Print-Knit, we initially focused on building blazers, sweaters, and dresses that can all move without restrictive seams. We challenged ourselves and the technology to create a blazer - a garment that requires significantly more structure than a sweater.
Structured Knit: We iterated over 10 different knit constructions before landing on a “links-links” technique (German for “left-left,” and named for the machine settings). Links-links is known for providing a high-density knit, with good resilience and high stretch in all directions. It gives the blazer the ability to have structure and body more similar to a blazer than a sweater.
Resilient Warmth: We use a blend of 72% viscose-rayon (a polymer derived from wood pulp) and 28% PBT (polybutylene terephthalate) which is a type of polyester known for its stretch and resilience. It works like elastane, except it doesn’t break down as easily - especially when exposed to chlorine. The viscose gives an extremely soft wool-like handfeel and matte aesthetic. These two combined, create resilient warmth that “feels like wearing a hug.”
3D Articulation and Ventilation: 3D Print-Knit enables us to create a garment with varied 3D structure, including articulated shoulders and elbows through a rib knit that enables stretch and a natural posture. Targeted ventilation through selectively placed pointelle stitches allows airflow in the underarm. One of our favorite structures is the skipping of a column of knots under tension at the lapel to constantly cause it to naturally fold wash after wash.
