One mold, 150 shapes: circular injection molding for the climbing industry
Climbing is all about feel, precision, and connection with nature. Yet most climbing holds are anything but sustainable. They’re made from virgin materials and, at the end of their life cycle, can’t be reused in new climbing applications. In addition, molds are used only 20 to 50 times, which significantly increases the CO₂ footprint of traditional climbing holds - both in material use and in production.
Greenholds set out to change that. Their goal: to develop a fully recyclable climbing hold that performs both technically and athletically. No compromise on grip or durability, but a solution that truly aligns with the values of the climbing sport. Together with ENBI, the team explored how to create a production process capable of making that ambition possible. The answer lay in a modular mold design and a re-engineered injection molding process.
Modular molds for maximum variation
Every climbing hold has its own shape and character. In conventional production, this means a separate mold for every model - costly, labor-intensive, and inflexible. To break through that limitation, ENBI, Greenholds, and Zuyd University of Applied Sciences developed a modular mold concept capable of producing more than 150 different shapes from a single base mold. The modular sections can be swapped or adapted without replacing the entire tool.
This concept combines efficiency with design freedom. It shortens lead times, reduces material usage, and makes sustainable series production feasible in a sport built on variation.
The right texture for real climbing feel
A good grip starts with the right surface texture. Traditionally, climbing holds are cast in silicone molds, creating a natural, rough finish. Injection molding works the opposite way: the process naturally produces smooth surfaces. The challenge was to bring back that characteristic “rock feel” in a process that inherently creates smoothness.
After numerous test series and rounds of feedback from climbers, the ideal balance was found. By applying a rediscovered technique and purposefully optimizing the mold surfaces, we achieved the desired combination of grip and tactile feel. The result: a visually distinctive texture with a natural touch, with injection-molding precision.
Material research for circular performance
In parallel with the mold development, extensive material research was carried out in collaboration with CHILL Labs. The challenge was to create a polymer that is fully recyclable yet offers the strength, elasticity, and grip climbers expect. In a next phase, the team explored how used climbing ropes could serve as raw material for new holds. To make this innovation scalable for industrial production, collaboration with Korrels B.V. ensured the recycled compound was optimized for series manufacturing. Together, these efforts created a circular chain in which used materials are given a second life as climbing equipment.
Three years of collaboration, one shared vision
Developing the sustainable climbing holds was an intensive three-year journey involving Greenholds, ENBI, Zuyd University of Applied Sciences, CHILL Labs and Korrels B.V.. From pre-engineering and material validation to modular mold concepts and surface structuring - every detail was tested, optimized, and documented. The result is a durable, high-performance climbing hold that unites technology, material, and functionality in one scalable production process.
This collaboration demonstrates how technical innovation can make sports more sustainable without compromising performance. What began as an ambitious idea evolved into a concrete production concept where circularity and climbing feel go hand in hand.
The collaboration with ENBI was defined by “thinking in possibilities.” Even when we asked for what seemed impossible according to injection molding rules, ENBI stood by our side with an innovative mindset. Thinking outside the box was more often the rule than the exception. Without the strong partnership with ENBI, we would never have achieved this result. - Geert Voncken, Founder
UNSEEN, YET ESSENTIAL!