Enhancing Thermal Insulation of building components through Custom Nozzle Design for Tubular 3D Printing
Channel: General ideas and needs in the field of additive manufacturing
Large-scale 3DP is constantly increasing in popularity as a commonly spread fabrication method in a wide variety of fields. However, in the field of architecture, the direct application of off-the-shelf large-scale pellet extrusion systems lacks efficiency regarding print time, material consumption, and therefore costs. These downsides are caused by the solid section of the bead used in off-the-shelf material extrusion (ME). This also results in the printing speed being limited by the slow cool-down rate of the thick extruded plastic.
At the chair of Digital Building Technologies (DBT) at ETH zürich, a novel approach to large-scale 3DP has been developed and patented, consisting of tubular extrusion 3DP (Matthias Leschok, 2023). This fabrication method allows for material savings between 50-80% and faster print speeds (from 3 to 8 times). Research so far focused on the process development of HC3DP, proving the aforementioned benefits in comparison to off-the-shelf ME.
HC3DP allows for fabricating bespoke, lightweight, time and cost-effective large-scale elements, achieving extrudate layer heights (LH) between 15mm to 30mm (5 to 10 times higher LH in comparison with off-the-shelf ME). The LH of the bead mainly depends on the nozzle size and the inner air pressure applied to inflate it while printing. Currently, only a prototypical fabrication setup exists with a basic circular crown nozzle. Improvements in the design of the extrusion method, specifically the nozzle, will directly advance the production of highly customized mono-material performative architectural elements. These elements could potentially utilize recycled feedstock, thereby enhancing circularity in manufacturing.
Through the support of IBAM Innobooster, our project aims to adapt and refine the extrusion system for building-scale applications, focusing on enhancing thermal insulation capabilities. We propose to investigate two key aspects of HC3DP nozzle extrusion technology:
1. Outer Geometries: We will investigate a set of bespoke, non-circular nozzle geometries for their printability. Specifically, we aim to assess how these geometries influence facade-related performance metrics, such as layer bonding and overall structural integrity.
2. Internal Geometry: Furthermore, our research will focus on the design and customization of internal nozzle geometries to potentially improve thermal insulation and structural performance.
The project will be structured into three phases:
Phase 1: Design and Fabrication of Bespoke Nozzles
Collaborating with our industry partner, SAEKI, we will design and fabricate a range of bespoke aluminum 3DP nozzles tailored to our project’s objectives.
Phase 2: Nozzle Testing and Extrudate Behavior Analysis
Each bespoke nozzle will undergo rigorous testing with HC3DP technology to evaluate printability and the behavior of the extrudate. This phase will provide valuable insights into the performance characteristics of different nozzle geometries and their suitability for building-scale applications.
Phase 3: Insulation Performance Testing at ETH
In collaboration with ETH, we will assess the insulation performance of HC3DP elements. Comparative analysis will be conducted between our prototypes and equivalent industry products, such as polycarbonate panels, to benchmark performance and validate the efficacy of our approach.
The project aims to advance HC3DP technology for building-scale applications, with a specific focus on enhancing thermal insulation capabilities, enabled through advancements in the fabrication setup. Through collaboration with industry partners and academic institutions, we seek to drive innovation in sustainable construction practices and contribute to the development of energy-efficient building solutions, implementing the novel field of nozzle design and customization, complementing big-scale HC3DP.
