Temperature and Humidity Variation Effect on Process Behavior in Electrohydrodynamic Jet Printing of a Class of Optical Adhesives

Abstract

Electrohydrodynamic jet (e-jet) printing is an emerging additive manufacturing process that utilizes an electric field to eject material from a micro-/nano-scale microcapillary nozzle. Due to its contemporary nature and the complex physics which govern the process, little is known about printing behavior sensitivity with respect to environmental condition variability. The aim of this work is to construct a systematic experimental design to test and evaluate the relationship between two environmental variables, temperature and relative humidity, and key process metrics initiating ejection voltage, printing frequency, and diameter of material ejected. A factorial statistical design of experiments is used to investigate the parameter space. Results are used to identify temperature and humidity ranges that give robust printing regimes for a specific class of optical adhesives. Best-fit curves are determined for several of the input-output relationships, which provide a predictive model for the ink behavior.