Development and feasibility analysis of concept 3D printer using TPR

Sammanfattning: The overall project objective was to investigate the feasibility of using thermoplastic rubber (TPR) pellet in combination with the fused deposit modeling technique to create 3D objects. The commercially available pseudo-rubber printers available today uses photosensitive binders or laser sintering in the build process. These are however both expensive and exhibits poor mechanical strength and performance making them unsuitable for production of real life application parts. There are currently no 3D printers available that are capable of printing full strength TPR parts at a reasonable cost. One can imagine that such a printer could be applied in a range of areas such as medical applications, orthotics, packaging, toys etc. To investigate the feasibility of such a printer a printhead was manufactured and tted onto a low cost UP! printer frame with some slight modications in order to make them compatible. Different rubber grades was then tested and evaluated based on quality, consistency and mechanical properties. Prototypes was then produced to see how the process handles larger builds. Results shows that printed parts exhibit good dimensional accuracy and capable of producing parts with roughly about 33-80% the strength of injection molded reference pieces depending on the rubber grade used. More work is however needed both on the hardware and software side. A software needs to be more or less modied and optimized to comply with the properties of TPR for stronger and more consistent prints. The hardware of the printhead and frame also needs to be overlooked and redesigned in order for more complex features such as overhangs, thin walled and high detail features to be made.