Abstract
Multi-jet fusion (MJF) parts are by default electrically insulative, meaning they have high Surface Resistance values (> 10^11 Ohms) and prevent or limit the flow of electrons across their surface or through their volume. However, the carbon black present in the Fusing Agent (FA) is conductive, and, with a sufficient drop concentration, it can create structures with lower electrical resistance and ESD or antistatic properties.
However, surface reistance values not only depend on the FA concentration, but also on the irradiance received by the part. As it is a surface property, it is very much affected by the energy received in the surface of the part. When an excess of energy is applied to the outer layers of the part, this might overheat the white powder in the surroundings, fusing small particles on the surface. This effect, known as blooming, locally reduces the FA concentration, increasing the surface resistance. Nevertheless, if there is a lack of energy to avoid blooming, there might appear part quality issues associated to cold parts, mainly elephant skin. Thus, when designing an ESD printmode in MJF it is crucial to tune the energy irradiance to find the perfect balance between part quality and surface conductivity.
In this article we present an idea to tune the ESD printmode by printing the same level of parts and different fusing irradiances, allowing the customer to balance ESD properties with the desired look and feel.
Creative Commons License
This work is licensed under a Creative Commons Attribution-Share Alike 4.0 License.
Recommended Citation
INC, HP, "Workflow to tune the ESD printmode", Technical Disclosure Commons, (November 17, 2024)
https://www.tdcommons.org/dpubs_series/7542