Experimental Investigations for Statistically Controlled Rapid Moulding Solution of Plastics Using Polyjet Printing

Abstract

Rapid prototyping (RP) has been in evidence for the past twenty years and is being widely used in diverse areas, from the building of aesthetic and functional prototypes to the production of tools and moulds for technological prototypes. The purpose of the present study is to experimentally investigate statistically controlled rapid moulding (RM) solutions for plastic components using polyjet printing (PP). Starting from the identification of component/benchmark, prototypes with three different type of plastic material were prepared, at different orientations. Measurements on the coordinate measuring machine helped in calculating the dimensional tolerances of the components prepared. Some important mechanical properties were also compared to verify the suitability of the components. The study highlighted the best orientation, support material quantity and type of plastic material for the selected component from dimensional accuracy and economic point of view as RM solution for plastic components. Final components prepared are acceptable as per ISO standard UNI EN 20286-I (1995). This process ensures rapid production of statistically controlled pre-series technological prototypes and proof of concept at less production cost and time.

Process capability study of polyjet printing for plastic components

“…Finally, vero white material in horizontal position has been selected for PP, because it provides close value of dimension (that is minimum deviation from the nominal dimension). Further as observed from Table 2, IT grades (for all three plastic materials) achieved in PP process are in machining range [6,7,9] confirming high profileaccuracy.…”

“…In the process of PP, jetting head slide back and forth along the x-axis similar to a line printer, depositing a single super thin layer of photopolymer [5,7]. After building each layer, UV bulbs alongside the jetting bridge emits UV light, for immediately curing and hardening of each layer.…”

“…1 shows schematic of PP process. Two different photopolymer materials are used for building, one for the actual model and another gel like material for supporting [7]. When the build is finished water jet removes the support material, leaving a smooth surface.…”

“…This paper highlights experimental investigations on PP for improving profile-accuracy, surface finish and reducing production cost of plastic components for industrial applications. Final components prepared are acceptable as per ISO standard UNIEN20286-I (1995) and DIN16901 standard [5,6].…”

“…PP is relatively new form of RM [4]. The process of PP was patented in 1994 by Sachs et al under U.S. patent number 005340656 [5]. The PP based on the MIT's (Massachusetts Institute of Technology) ink jet technology in a variety of printer is considered to be one of the most future oriented rapid prototyping (RP) systems [3].…”