Dimensional Evaluation of Additive Manufactured Polymer Extrusion Dies Produced by Continuous Liquid Interface Production

In profile polymer extrusion, the die is one of the critical element of the process and it allows to produce kilometers of extrudates with very complex cross-sections at high production rates. However, the design phase of a die usually results to be a time-consuming and cost-intensive phase of the manufacturing process chain. Moreover, tight dimensional tolerances and accurate surface finish are extremely important attributes for the proper functioning of the extrusion products.
In the delopment phase of new extrudate products, Additive Manufacturing (AM) has the potential to be an appropriate technology for the manufacturing of extrusion polymer dies in order to shorten lead time and pilot production costs. Continuous Liquid Interface Production (CLIP) is a recently developed photopolymer-based AM technology and it has been selected for facing these challenges.
In this study, polymer AM dies have been produced in CE221, a photo-resin with high thermo-mechanical properties with Continuous Liquid Interface Production (CLIP). The polymer dies were tested on an industrial production line and proved to be able to withstand the demanding process conditions, yielding up to 300 m of extruded product. The capability of the newly established process manufacturing chain was demonstrated to be comparable with the conventional process chain based on machining of tool steel dies in terms of surface finish and dimensional accuracy.
The material selection for the die manufacturing was vital to prove this new concept and no tool failure occurred during the production. Manufacturing accurate tools is indeed necessary in order to meet the demanding quality requirements and this is another challenge that has to be fullfilled. A dimensional metrology study on selected features of the AM fabricated dies was performed. The analysis highlighted the most relevant issues that must be taken into account and managed before a successfull integration of the AM technology in the extrusion process chain can be realized.