Easily applicable protocol to formulate inks for extrusion-based 3D printing

Abstract

3D printing is a disruptive technology that is a key driver of the new industrial revolution. Among the various 3D printing methods, direct-ink-writing (DIW) takes a viscous ink material, extrudes it through a nozzle, and deposits it layer-by-layer to create 3D objects. DIW is a versatile method that can print ceramics, polymers, metals, living cells, etc. Yet, the ink formulation is critical for the success of printing. One major challenge to operate the transition to Industry 4.0 is to educate laypersons on 3D printing, without the need to master physics and chemistry. In this paper, we propose a protocol to familiarize laypersons with ink formulation for DIW. Using this protocol, a clay-based ink was optimized and the best ink composition containing 48 wt% clay and 2.4 wt% bamboo fibers was used for printing. The experimental set-ups and details used in the work are easily available, cheap, sustainable, and safe, enabling its implementation in various settings from classrooms to workshops, without the need for specialized equipment.

Rheology and Printability of a Porcelain Clay Paste for DIW 3D Printing of Ceramics with Complex Geometric Structures

“…During the DIW 3D printing process, the properties of the precursor (ink, slurry, or paste) are the most crucial for printing performance. For current printing inks, the corresponding printed samples have low molding accuracy, high firing shrinkage, and low strength, limiting the application scope of this technology in the porcelain field. , However, for the high solid loading paste suitable for manufacturing porcelain, it is a complex and challenging issue to design the porcelain clay paste with an appropriate rheology threshold before printing, avoiding the occurrence of clogs and slumping during printing and retaining its shape after printing . For this issue, some scholars have reported relative findings, such as clay formulation, modifier type and content, − surface modification, − printing parameters, − and solids volume fraction, which are controlled to improve the rheological behavior of the precursor, achieve good printability and physical properties, and prepare high-precision 3D printing samples.…”