Making Futures Journal
New Tools for Ceramic Extrusion: Developing Craft Experiments into Industrial Applications
The Use of Digital Design and Fabrication technologies in Ceramic Production
Initial Craft-based Experiments with Ceramic Extrusion and 3D Printed Dies
The dies were fabricated on low-cost MakerBot 3D printers which work via the Fused Deposition Modelling (FDM) principle through the use plastic filament as the build medium. For the dies in these initial experiments ABS plastic filament was employed. The initial results were not encouraging with the dies consistently being crushed by the extrusion pressure. In this regard it is relevant to note that FDM 3D printing typically creates parts that consists of a solid skin but have an interior that is printed with a loose three-dimensional mesh, known as infill. This infill typically only constitutes 10-30% of the volume of the interior space of the parts. The reason for this approach is to minimise printing time and also to reduce material use – and consequently the cost of the parts. FDM 3D printed parts are very rarely printed with a solid infill due to excessive printing times such an approach would result in. However, the 3D printing approach with the sparse infill seemed to be just part of the course for the dies to fail.
The layered nature of 3D printing parts also seemed to course inherent structural weaknesses in the dies in term of de-lamination of the horizontal layers. Particular the supporting beams, known as bridges, which holds the central core of the die in place seemed particularly woundable in this aspect. In response to this challenge a hybrid approach was adapted where 3D printed parts were combined with metal inserted for the bridge components. The dies were specifically designed with slots to incorporate not only bars but also holes for bolts and plates to prevent the die from de-laminating along the 3D printed layers. This approach proved to be successful in alleviating the structural failures.
To aid the design iteration process the authors developed a parametric script in Grasshopper, the visual programming environment within the Rhino 3D CAD software. This Grasshopper script (which is commonly known as a definition) enabled the author to iterate the design of particular elements of the die while other parts would update automatically.
Another term which the author proposes as a result of these the creative experiments is: Jugstrusion(s). The author presents this as description of the particular concept of creating ceramic jugs via the extrusion process, the full description is presented below in figure 7:
Innovation Opportunities for Extrusion in Architectural Ceramic Production
Developing a Low-Cost Hydraulic Clay extruder
The frame of the system was constructed with parts from the Unistrut system (mostly from university shelving surplus). Throughout the development and construction of the extrusion system an approach of direct construction without prior design plans or detailed drawings was employed. This methodology is closely associated with development methodologies employed in maker and hacker communities, which can be seen reflected in statements such as the ‘Cult of Done’ (Pettis 2016). Arguably, craft practice can be characterised by similar approaches, where ‘trial and error’ based experimentation is typical the basis for the development of new ideas. This type of methodology has the capacity to enable a rabid progression of a concept, particularly if reconfigurable systems are employed. In this particular case the use of the Unistrut system enabled corrections of errors and iterative improvements to be easily implemented through the repositioning of parts.
Further development of the parametric scrip for creating extrusion dies
In parallel with the development of the ram extruder system, improvements to the grasshopper script to create extrusion dies were also carried out to enable the software tool to perform in relation to architectural/industrial applications. One objective in this development was to develop the scrip to a stage where users with little CAD expertise could create the 3D die design files. A key aspect in this regard was to enable automated generations of the 3D geometries purely from numerical input. This objective was successfully achieved with the script now having the capacity of generating designs from number sliders that can determines all the key aspects of the die design. The script also has the facility to automatically generate multiple, separate elements of the die.
Initial test of hydraulic ram extruding system and new generations 3D printed dies
The initial test of the ram extruder and 3D printed dies from the improved Grasshopper scrip was carried out in February 2020. The ram extruder system was still lacking refinement and tuning, but still showed very significant potential in the tests. Extrusion pressures in excess of 40 bars was employed, which is more than the pressure levels that are commonly use in industrial brick making (usually around 20-30 bars). The Unistrut frame construction has so far shown no sign of stress deformations. Equally, the 3D printed dies tested with the system have also performed well with no breakages experienced. Two different diameter tubes were tested with the system, both with a fine polygon outer to facilite facets in the extruded shape that enabled the researchers with visual evidence of any distortion or twisting in the extruded test shapes. The production of straight extrusions was assisted by the use of pieces of upholstery foam in combination with a roller table to alleviate possible distortion of soft extruded shapes.
Further work to implement knowledge from research in industrial contexts
While the impact of the coronavirus has meant that further practical tests with system has temporarily been suspended, a clear vision of creating impact with the research in industrial contexts remain. The motivation for this effort is driven by an ambition to prove that knowledge initially developed in creative craft practice situations, can have real potential for providing innovation in different sectors or scale of productions – in this case, the architectural ceramic industry. However, transferring knowledge between different sectors requires carefully consideration so that contributions have a genuine value in the new context. This research is being developed with project partners that are leading global companies, including: Arup (engineering, architecture), Sibelco (clay and raw materials), Wienerberger (brick and architectural ceramics products) and Centre for Window and Cladding Technology (CWCT) - building industry organisation for ensuring standards, construction guide lines and safety.