Collaboration Advancing Sustainable Acoustics: Testing innovative acoustic insulation made from sheep’s wool

To de-risk the market entry of LAMDA (an environmentally circular, wool-based rigid acoustic insulation product) this project partnered Wull Technologies with the University of Sheffield to address the bottleneck of slow, costly physical testing. Through the development and application of a predictive acoustic model, an accelerated route to commercialisation for sustainable construction materials has been unlocked.

Background and context

The UK’s built environment faces an urgent need to decarbonise. Imminent regulations, including mandates by the Future Homes Standard for up to 80% reduction in carbon emissions, are placing pressure on the construction industry to rapidly reduce their environmental impact. Concurrently, increasing urban density and the architectural shift towards lightweight construction materials have heightened the demand for effective acoustic insulation.

Despite these shifts, the £220 million UK acoustic insulation market remains dominated by energy‑intensive mineral wool and high‑carbon petrochemical foams. These incumbent products rely heavily on fossil fuels, possess high embodied carbon, and present significant recycling and end‑of‑life challenges.

To address this, Wull Technologies developed LAMDA, a fully recyclable, rigid acoustic insulation panel manufactured from natural and recycled British sheep wool. Unlike conventional soft-roll wool, LAMDA’s rigid structure enables use in wider applications such as baffles and wall panels in the built environment, as well as in thermal protective packaging and growth media. This material innovation embodies circularity principles, providing high value application for coarse sheep wool, currently viewed as a waste by-product by farmers.

While such sustainable alternatives present clear benefits, they face a severe commercialisation bottleneck due to the high costs and protracted timelines associated with traditional physical testing. In the acoustics sector specifically, product development requires bespoke physical prototyping and compliance testing to comprehensive standards. With a single ISO test iteration typically costing more than £6,500 over a 10-to-18-week timescale, this presents a critical barrier to entry for an SME prior to scale-up.

To de-risk this process, adoption of numerical simulation, predictive modelling and laboratory characterisation requiring small material specimens is essential to reduce the burdens of early-stage product development. However, some existing porous-media acoustic models cannot accurately simulate the complex, anisotropic architecture of wool fibres within a rigid panel format so that careful model selection and refinement are required.

About the Project

Led by Wull Technologies, in collaboration with the University of Sheffield and The Henry Royce Institute (Royce), this project set to develop a validated acoustic model tailored to this novel bio-based material system. The model can also predict the in-situ performance of the new material accelerating product commercialisation in line with the housing sector’s demand.

Project Details and Results

The project was executed through a highly collaborative project between Wull Technologies and the University of Sheffield, interlinking measuring, modelling, and manufacturing in a rapid optimisation cycle. The project was divided into three interconnected work streams:

Materials Characterisation

Characterisation techniques used included Dynamic Vapour Sorption (DVS) and mercury intrusion porosimetry (MIP) facilities at Royce at Sheffield, to map the internal architecture of the panels and moisture response, Dynamic Mechanical Thermal Analysis (DMTA) X-ray micro-computed tomography (Micro-CT) to assess structural integrity and pore topology, and upgraded impedance-tube testing, to capture the material’s complex acoustic wave propagation and absorption behaviours.

Findings confirmed that the proprietary manufacturing process successfully compacts the fibres while retaining a highly effective acoustic porous network, with the hollow fibres providing dual acoustic and thermal insulation, as well as efficient moisture regulation.

Simulation and Prediction

Based on the captured empirical data a predictive digital tool was developed. In doing so, a validated digital twin of the LAMDA panel was proven to accurately mirror real‑world testing. This breakthrough capability allows Wull Technologies to virtually predict and optimise product performance for different client applications (eg different wall build-ups), avoiding the traditional arduous route of costly trial and error.

As an initial test case, a transmission loss simulation was run to assess the material’s performance within standard external wall build‑ups. The virtual simulations enabled proof that a single layer of LAMDA material offers acoustic performance comparable to a double‑layer plasterboard system with empty cavities, establishing its acoustic competitiveness against established commercial insulation products.

Process Optimisation and Scale‑Up

Having gained material performance insight, Wull Technologies was able to progress with confidence to manufacturing process optimisation and pilot-stage scale-up, leveraging high-bay facilities at the Graphene Engineering Innovation Centre (GEIC).

Batches of LAMDA, derived from natural sheep wool and recycled wool feedstocks, were fabricated and tested for comparison of their respective microstructures, porosities, and acoustic behaviours. Results demonstrated that both products could be effectively processed into high‑performing rigid acoustic panels, illustrating viable integration of a circular supply chain.

With this validation, production was progressed from small laboratory prototypes to full commercial panel dimensions. This successfully transitioned LAMDA from a laboratory concept to a commercially viable, competitive product, capable of meeting the urgent demands of the built environment.

Impact & Next Steps

Royce’s provision of both targeted public funding and advanced materials testing infrastructure delivered the foundational empirical evidence required to bridge microscopic materials science with macro scale acoustic engineering. For an SME such as Wull Technologies, this support has been critical to de‑risking complex research, development, and certification pathways, projected to cut overall development time and validation costs by up to 70%. In doing so, the necessary assurance has been gained to secure the financial runway for continued scale-up.

Providing this valorised pathway to offcut wool could also realise significant economic benefits to agricultural communities. With farmers often paying more than £1 to shear each sheep, yet receiving only 15–30 pence per fleece, transforming what is currently viewed as waste product into profitable supply has the potential to provide a sustainable revenue stream for rural farms.

Further social benefits could be achieved through the proven effective acoustic absorption of the LAMDA material, contributing to healthier and more resilient living environments.

With the aid of the advanced modelling developed through this project, the initial focus for Wull Technologies is to establish LAMDA as a performance-credible and certifiable acoustic material to address this market need in the built environment sector. Longer-term, the accelerated product development cycle will seek to enable further sectors to be explored for high performance, sustainable wool insulation.