Project Overview

As global temperatures continue to rise due to anthropogenic carbon emissions, the building sector remains a major contributor to the poly crisis as both a source of energy-related emissions and a primary driver of legacy extractive practices. While policies and certification programs have made strides in improving energy efficiency, reliance on carbon-intensive foam insulation and petroleum-derived synthetic building materials persists. This research presents a novel approach to decarbonizing the built environment by developing wool-biocomposite panels as exterior retrofit insulative cladding, leveraging waste wool as a sustainable alternative to conventional insulation materials.
This research introduces an upcycled wool bio-composite panel that capitalizes on the existing waste stream in wool production, where only a certain quality and grade of wool fibers enter the textile process chain. According to literature, at the production stage, only about 25% of the wool produced in Europe, and 5% in Italy in particular, is considered usable in the textile industry. In manufacturing, 10-15% of wool ends up as waste. In addition, the demand in the textile market is being overtaken by synthetic fibers, leading to an increase in surplus wool. While the potential of wool as an insulative material has been used for centuries and is well documented, scalability and durability concerns have hindered its widespread application.

Building off previous findings that indicate interior retrofitting of building insulations lacks reasonable CO2e and cost payback, this work introduces a novel biocomposite panel that aims to overcome these limitations by providing an exterior, retrofittable insulation panel that is a durable, structurally stable, and moisture-resistant alternative to traditional insulation.
The proposed retrofittable cladding system utilizes a novel “GHOO” (Grey Hydro Oxide Output) keratin-based biopolymer extracted from waste wool. This process involves alkaline treatment and mechanical energy to extract keratin-rich gel. The extracted keratin gel is then crosslinked with an organic acid and combined with residual wool fibers before being heat-pressed into rigid panels. This method eliminates petrochemical additives, resulting in a biocomposite with mechanical properties comparable to medium-density fiberboard. Further, depending on the composition of the GHOO polymer matrix, the residual wool fibers retain the natural ability to trap air through their kinks and bends, enhancing thermal performance, while the GHOO polymer matrix ensures mechanical stability and weather resistance.

Project Team

Jonathan Grinham
Leonard Palmer
Donald Oloruntobo
Jack Alvarenga

Collaborators

American Woolen Company
Tom Schroeder, NC State University

Mechanical performance is demonstrated using ASTMD790 three-point bending testing. Results show that the wool biocomposite exhibits mechanical strength equivalent to wood medium-density fiberboard. A full life cycle analysis evaluates the merits of transforming an underutilized agricultural byproduct into a high-performance and retrofittable building material, including the potential for biogenic carbon storage associated with intelligent regenerative sheep management in the Northeast United States. These novel upcycled wool bio-composite panels offer a viable pathway for reducing reliance on petrochemical-based insulation using a durable, structurally stable, and moisture-resistant retrofittable insulation panel that offers a regenerative design solution across the entire lifecycle ecology of a prevalent waste stream, wool.