Novel Additive Manufacturing of Tooling with Micro and Nanostructured Surfaces

L.W. Sit, M. Kumbhani, J.A. Genera, J. Shearer, J. Mead, C. Barry
University of Massachusetts Lowell, US

Keywords: additive manufacturing


Tooling with micro and nanostructured surfaces is employed for high-rate fabrication of products using injection molding, hot embossing, and related processes. Current subtractive (machining, lithography) and additive (prototyping) methods for manufacturing tooling are expensive and have significant limitations. So, a new technique was investigated for the rapid fabrication of tooling inserts with microfeatures. Green steel microscale patterns were printed onto steel substrates as a single layer using a 2D dispensing system and then sintered to produce the tooling. The resultant feature dimensions were measured using contact profilometry. For this method, the paste formulation (binder, particle size and loading, and solvent) and printing conditions (e.g., speed and pressure) were evaluated for their effects on feature dimensions, uniformity and smoothness. These results were correlated with paste viscosity. Moreover, this novel survived 5000 injection molding cycles without damage to the features.