A 1-Meter-Cube FDM Printer Just Made a Class A Acoustic Panel, Slowly

Large-Format 3D Printing Meets Acoustic Design

The acoustic panel was printed on Kentstrapper’s Mille, a machine with a 1,000 x 1,000 x 1,000 mm build volume. The design process involved parametric modeling using Rhinoceros and Grasshopper, allowing for precise adjustments to the panel’s geometry. The panel’s profile is sinusoidal, with perforations of varying diameter, which were optimized for acoustic performance rather than aesthetic appeal. This approach highlights the potential of 3D printing to create complex, function-driven designs that traditional manufacturing methods may struggle to achieve.

The panel’s acoustic performance was tested in a reverberation chamber at Z-Lab, following the ISO 354 standard. The results showed a weighted sound absorption coefficient (αw) of 0.90, which qualifies the panel as Class A under ISO 11654. This level of performance is significant, as it indicates the panel can effectively absorb sound across a range of frequencies. The design also incorporated a mineral wool layer behind the printed structure, which works in conjunction with the geometry to enhance sound absorption. This hybrid approach combines the benefits of both traditional and additive manufacturing techniques.

The REVERSING project, funded by the Tuscany Region, aims to develop sustainable retrofit solutions for existing buildings. Kentstrapper’s contribution to the project is an interior acoustic panel designed for use in classrooms and offices. The panel’s sinusoidal shape and variable perforation pattern were developed in collaboration with the University of Florence’s team, ensuring that the design met both acoustic and printability requirements. The project also includes other partners, such as Polistamp and Santelli Vetri, who are responsible for different components of the facade system.

The Role of Geometry in Sound Absorption

The production of the acoustic panel required eight individual components, each printed on the Mille with a 0.8 mm nozzle. Each component took approximately 56 hours to print, resulting in a total of 448 hours of machine time. The material used was PETG, with each component weighing around 2.5 kg. The slow printing speed was necessary to maintain the stability of the panel’s wavy surface during the process. This highlights the trade-off between precision and speed in large-format 3D printing, especially when complex geometries are involved.

The acoustic panel was tested against a standard mineral wool panel, and the results showed a significant improvement in sound absorption. At 500 Hz, the panel reduced reverberation time by 41%, and at 1,000 Hz, the reduction was 45%. It also improved the Speech Transmission Index (STI), a measure of how well speech is understood in a space, from 0.47 to 0.52. These results demonstrate the potential of 3D-printed acoustic panels to enhance the acoustic environment in educational and office settings.

The research findings were published in two academic papers: “Designing Sound with Geometry: A Hybrid 3D-Printed Acoustic Panel” in AM Perspectives and a second paper in TECHNE, the University of Florence’s architectural technology journal. These publications provide a detailed analysis of the panel’s design, testing, and performance. The research also highlights the role of parametric design in optimizing acoustic performance, showing how 3D printing can be used to create tailored solutions for specific environments.

Testing and Validation of the Acoustic Panel

The REVERSING project is part of a broader initiative to improve the energy efficiency of existing buildings. By using prefabricated, dry-assembled facade systems, the project aims to reduce the environmental impact of building retrofits. Kentstrapper’s acoustic panel is one of four key components in this system, designed to enhance the acoustic comfort of interior spaces. The project’s focus on sustainability and performance aligns with current trends in the construction industry, where energy efficiency and occupant well-being are increasingly important.

The collaboration between Kentstrapper and the University of Florence involved close coordination between the design and manufacturing teams. The parametric model was developed using Rhinoceros and Grasshopper, allowing for real-time adjustments based on acoustic simulations. This iterative process ensured that the final design met both functional and technical requirements. The involvement of Luciano Cantini, co-founder of Kentstrapper, in the development of the FDM process further underscores the importance of industry-academia partnerships in advancing additive manufacturing applications.

Collaboration in the REVERSING Research Project

The use of 3D printing in architectural acoustics represents a shift from traditional methods that rely on mass and porosity for sound absorption. Instead, this project demonstrates how geometry and material properties can be combined to achieve high-performance acoustic solutions. The panel’s design is not just a technical achievement but also a demonstration of how 3D printing can be used to create customized, high-value components for the construction industry. This could open new possibilities for future applications in both residential and commercial settings.

The results of this project have implications beyond the REVERSING initiative. They suggest that large-format 3D printing can be used to create complex, function-driven components that are not easily achievable through conventional manufacturing. The ability to print intricate geometries with precise control over material distribution could lead to new innovations in acoustic design and building materials. This project also highlights the potential for 3D printing to contribute to sustainable construction practices by reducing waste and enabling more efficient use of resources.

As the construction industry continues to explore new technologies, the integration of 3D printing into architectural design and manufacturing processes is becoming more prominent. This project demonstrates how additive manufacturing can be used to create high-performance, customized components that meet specific functional requirements. The success of the acoustic panel in achieving Class A sound absorption marks a significant milestone in the application of 3D printing to architectural acoustics, paving the way for future developments in this field.