Eco Innovation

Strides in Sustainability

Saucony / Triumph RFG (Run for Good) In addition to its corn-powered PWRUN BIO+ midsole made with 55 percent Susterra, the Triumph RFG features plant-based dyes in the upper and an 80 percent natural rubber outsole that is engineered to offer the same level of performance as a synthetic sole. (Susterra is made with “dent” corn, a product used primarily in industrial applications. The product is known technically as “1, 3 Propanediol (PDO),” an organic corn-based colorless viscous liquid miscible with water.)

There is no shortage of creativity in the footwear world these days, especially when it comes to new materials and digitalization methods. Eco-alternative textiles and components along with cutting edge design techniques are exciting areas to watch in the coming seasons as footwear companies continue to extend the range of styles that prioritize sustainability without sacrificing functionality and comfort. Performance brands are stepping up efforts to eliminate the use of PFAS (forever chemicals) and taking a forward-thinking approach to the use of bio-based fabrications. The latest looks also are directional in terms of design as suppliers increasingly turn to 3D and other next-gen techniques for ideation and product creation. Hurdles remain, but there’s no doubt that circular shoe solutions are on the fast track.  

A Sticky Situation

Finding adequate eco-conscious replacements for footwear components is difficult, with glue often cited as the biggest challenge. Currently the eco-friendly glue landscape is heavily focused on water-based polyurethane glues, that, unlike solvent-based glues, are low-VOC, reduce the use of hazardous chemicals, are non-flammable, and use water as the activator.

OrthoLite recently introduced its patented Fiber-Fusion Technology that eliminates the need for glue, mechanically bonding Electrostatic Discharge (ESD) conductive copper fibers into the OrthoLite X35 base layer. The company notes that the new technology goes beyond existing ESD protection for traditional insoles. The proprietary top-cover system features in OrthoLite’s new ESD Shield insole.

Bio-based hot melt adhesive is another eco-friendly glue emerging. This type of adhesive uses renewable raw materials such as corn, potatoes, tapioca, and certain vegetable oils as a percentage of the adhesive recipe, explains  Rob Falken, VP of Innovation for OrthoLite, adding that hot-melt adhesives are solid at room temperature but become molten when heated, allowing them to bond materials as they cool and solidify. “It is still early days in the mass commercialization of a synthetic eco-friendly glue that can withstand the rigors of footwear manufacturing such as water resistance, exposure to high heat, and long-term use coupled with bending and flexing,” states Falken.

Corn-Powered Cushioning

Saucony’s most sustainable shoe to date, the Triumph RFG, launches with a unique midsole material called Susterra, a branded, regeneratively grown, corn-based product. “It’s the first example we’re aware of where this percentage of bio-based content (55 percent) is used in the midsole of an athletic shoe,” says John Hurban, VP global marketing/sales, CovationBIO PDO. “We believe runners and fitness enthusiasts will benefit from increased high-performance shoe flexibility, comfort and durability. This shoe sizes up against the competition and goes the distance to have a lighter environmental footprint.”  The Triumph is part of Saucony’s sustainability push to have 90 percent of its products contain organic, recycled or renewable materials by 2025, with 100 percent by 2030.

Design Directions

BOA uses innovative tools across both its Performance Fit Lab and within the Partner Product Innovation & Development department from a range of 3D technologies, for fit, function and prototyping to the latest in Machine Learning/AI. “We use machine learning to digest vast amounts of data and fit patterns to our data to see if it backs up our hypotheses,” explains Dan Feeney, senior director of Partner Product Innovation & Development. “For example, we have motion capture data from each time an athlete touches our force plates. This data allows us to ‘parameterize’ movement (or fully describe it) where we know which movements are better than others. We used machine learning models to quantify which aspects of fit drive better performance.”

Here’s a handful of new styles kickin’ it when it comes to sustainability:

Merrell / Scrap

Scrap is a limited run footwear collection crafted from excess materials not used in production and includes three styles. Each shoe upper features leftover scraps that are uniquely placed, cut, and stitched onto the footwear. The Scrap line was released in September in honor of Zero Waste Week, an international campaign.

Scarpa / Spin Planet

The new Spin Planet, part of the company’s Planet range, has an upper constructed from 100 percent recycled fibers, while the EVA midsole contains 45 percent recycled material and the rubber outsole 30 percent. Scarpa describes the Spin Planet as its most eco-friendly long-distance trail-running shoe ever.

Decathlon / 3D printed performance shoe

A collaborative effort between French sports retailer Decathlon, U.S. printing technologies developer HP, and Italian knitting machinery maker Lonati, “reshapes” the sustainable footwear landscape through improved customization, repairability, localized production, and simpler end of life recycling.

Oboz / Cottonwood

The Cottonwood is Oboz’s most eco-friendly footwear to date. Designed with done-in-a-day hiking adventures in mind, the versatile shoes are PFAS-free, with over 20 percent of the material (by weight) derived from environmentally preferred materials. Also notable is the brand’s recently received B Corp status.