Study on ink flow of silicone rubber for direct ink writing

Abstract

Direct ink writing of soft materials is a very promising technology in 3D printing, and the rheological properties of inks are crucial for successful printing.In this paper, the effect of the rheological properties on the printing process of silicone rubber inks is studied to lay a foundation for the configurations of 3D printing process parameters. Also, the shape retention of the printing filaments is studied to provide a basis for the viscosity deployment of the inks. In addition, by studying the die swell ratio of nano-silica-reinforced silicone rubber inks at normal printing speed, it is found that the die-swell ratio is proportional to the ink's relaxation time. Finally, the influence of the configuration of the short-nozzle on the die swell is investigated, and the concave nozzle has a smaller extrusion swelling effect than the convex nozzle and the conical nozzle, providing new ideas for the adjustment of the filament diameter.

3D direct-write printing of water soluble micromoulds for high-resolution rapid prototyping

“…It should be noted that the extruded filament did show die swelling effect after exiting the nozzle [42] . Additionally filament wetting may reduce the final dried up height of the extruded filament on the substrate.…”

A Heating-Assisted Direct Ink Writing Method for Preparation of PDMS Cellular Structure with High Manufacturing Fidelity

“…Figure 3 b,c shows the mesh division results and boundary condition settings, respectively. According to the literature [ 21 ], the Herschel–Bulkley model was chosen for the viscosity and shear rate model in the simulation. The parameter settings are shown in Table 1 .…”

Bioinspired toughening of soft elastomer via embedded three‐dimensional printing

“…25 Printing silicone elastomers by DIW is more challenging because the elastomer precursor is not thixotropic; it is difficult to hold the shape after extrusion. 26 In addition, the curing of the precursors requires a prolonged time, which could lead to further deformation or even collapse of the printed structure. Lewis's group developed an embedded DIW method that involved extruding viscoelastic inks within a support bath, allowing free-form fabrication of complex architectures.…”

“…Printing silicone elastomers by DIW is more challenging because the elastomer precursor is not thixotropic; it is difficult to hold the shape after extrusion 26 . In addition, the curing of the precursors requires a prolonged time, which could lead to further deformation or even collapse of the printed structure.…”