UNIVERSITY PARK, Pa. — From the top of Penn State's indoor rock climbing wall, climbers can enjoy views of Beaver Stadium, Rothrock State Forest and even a sunset over Happy Valley.

From the ground, Colin Geary and Nelson DiBiase, biorenewable systems majors in Penn State’s College of Agricultural Sciences, saw something different: a sport inspired by nature, using a wall’s worth of plastic.

Geary, of Birdsboro, and DiBiase, of Normalville, both worked as managers at Penn State’s indoor climbing wall in the Intramural Building. The two students discussed their desire to pursue a capstone experience and were eager to combine their passion for rock climbing and sustainability — which is when they decided to create a fully biobased climbing hold.

Rediscovering the process

Penn State’s climbing wall, like most indoor gyms, utilizes a plywood base to create a 40-foot structure that emulates an outdoor rock face. Along this wall, specific climbing routes are created using petroleum-based climbing holds of varying shapes and textures. These holds imitate the details found on an outdoor rock face that climbers use to ascend walls.

“They made a fascinating case: The users of these products, the climbers, are very much in tune with the environment and preserving it,” said Jeffrey Catchmark, professor of agricultural and biological engineering. “They want to be a part of nature, but because of their enthusiasm for that, all of these unsustainable products are being produced.”

Drawing from his specialization in sustainable materials, Catchmark served as an adviser to Geary and DiBiase for their project.

Unlike similar majors such as biological engineering, the biorenewable systems program, introduced in 2013, does not yet offer a capstone course, which is an opportunity for students to address a real-life design project. While faculty are designing such a course for the major, Geary and DiBiase sought out such an experience through an independent study during their senior spring semester.

Over one semester, Geary and DiBiase designed several climbing holds of various materials and successfully created a prototype of a fully compostable climbing hold. They began by learning the process through which climbing holds are created, drawing practices from companies such as Kilter Grips.

To create a climbing hold, the shape must first be designed, typically using petroleum-based shipping foam, and then a mold is cast using silicon. Unfortunately, these materials are neither compostable nor recyclable.

“It’s not just what the hold is made of that we were trying to research, but the whole process that we were trying to rediscover,” said DiBiase.

Their first step to innovating the process was to recreate the shaping method. Instead of sanding down plastic foam for each individual hold shape, the students utilized reusable shaping clay.

“Instead of throwing away objects, we could reuse the same clay to shape each hold and cast it,” DiBiase explained.

Committing to sustainability

The next step was to innovate a replacement for the plastic material of the holds. Their first instinct was wood, which is used in some gyms and is typically much cheaper to produce. However, wooden holds are restrictive in terms of shape and texture. In addition, wooden holds are made of plywood and utilize layers of glue, which did not meet their standard for sustainability.

Instead of using wood for the entire hold, Geary and DiBiase considered creating a hybrid hold using a wooden base and another material that could bind to the wood. Following the lead of many other companies, the students created a prototype using EcoPoxy, a high-percentage biobased type of epoxy resin.

Like the materials used in traditional climbing holds, EcoPoxy is a two-part resin, which is why Geary and DiBiase anticipated its success. After they poured the mold and let the EcoPoxy cure for 72 hours, the students had made their first prototype.

Although EcoPoxy is biobased, it is not fully compostable because it is composed of, at most, 70% biobased materials. The alternative to EcoPoxy was PLA, a corn-derived polylactic acid — one of the very few fully biodegradable plastics. The problem with PLA is that it is much more difficult to use than a material such as EcoPoxy.

“They encountered a problem that a lot of companies and organizations that want to be sustainable have, which is they found options that are easy to implement, but not as sustainable,” Catchmark said. “Then there are sustainable options, but they are harder. They had to decide whether to take the easy way out and have a half-compostable, half-sustainable mold, or to make the effort to go all the way.”

As the students moved forward with PLA, they began to have doubts.

“PLA requires heating in order to take the shape of the silicon mold used,” Geary said. “This worked on our small-scale test, but when we tried this full scale, the silicon mold melted.”

Demonstrating the principle

Catchmark noted that although the temperature required for PLA holds melted the silicon mold, “it demonstrated the principle that you could take PLA and make a mold out of it. All they would need is a little bit of time.”

Geary and DiBiase’s findings offer the possibility of a fully compostable climbing hold. Their project was aimed at aligning scientific and business practices with the ethics of sustainability, the trademark characteristic of the biorenewable systems program in the College of Agricultural Sciences.

Both Geary and DiBiase graduated in May. DiBiase will attend Chatham University to pursue a master of business administration and master of sustainability dual degree this fall. Geary recently began his position as an inside sales representative at Bluelinx Holdings, a wholesale distributor of building and industrial products.

“Entrepreneurship isn’t about starting companies — it’s a state of mind where you see endless possibilities,” Catchmark said. “It’s in people who are ready to cut down barriers and do something no one’s done before. It’s a characteristic, and they’ve got it.”