Novel Solvent-based Polyimide Ink for 3D Printing Technology

Materials and processes for space applications raise several challenges, including low mass requirement, small production series, and very high performances. Additive manufacturing (AM, also known as 3D printing) is well-suited for space applications: it is adaptive to very small series, applicable to a wide variety of materials, allows for complex geometries, short lead time, and minimal material waste. Space applications may include RF hardware, antennas, solar panels, lightweight structures, joint elements, and electronics housing. However, before AM can be widely used in space programs, multiple challenges should first be resolved, including development of space-qualified materials.

PolyJet 3D printers jet layers of multiple liquid photopolymers onto a tray, which are then cured by UV light. Yet, the requirements from ink materials are numerous and challenging. The ink should have suitable properties for jetting and printing, such as low viscosity, high solid content, fast curing, specific surface tension, environmental friendly, chemical compatibility with printer materials, and more. The printed material intended for space application should have also properties which make it durable to the space environment.

Polyimides (PIs) are very attractive polymers in space applications due to the superior properties they possess, including high thermal stability, excellent mechanical properties, wear resistance, radiation resistance, chemical stability, low dielectric constant, and good adhesion strength. However, PIs are not available in Polyjet technology so far.

This work presents the development of a new solvent-based PI-like ink. The developed ink is an environmental friendly solution with high solid content and low viscosity at jetting temperature. For the first time, PI-like 3D objects were printed using Stratasys 3D printer (Connex 500). The printed PI was characterized in terms of mechanical, thermal, chemical and electrical properties.

Its durability to the space environment was confirmed by demonstrating very low outgassing, ionizing radiation resistance, low dielectric constant and high thermal stability.