Greenwood Taylor E, Hatch Serah E, Colton Mark B, Thomson Scott L
Department of Mechanical Engineering, Brigham Young University, Provo, UT, 84602, USA.
Addit Manuf. 2021 Jan;37. doi: 10.1016/j.addma.2020.101681. Epub 2020 Oct 31.
Embedded 3D printing processes involve extruding ink within a support matrix that supports the ink throughout printing and curing. In once class of embedded 3D printing, which we refer to as " embedded 3D printing," curable inks are printed, cured, then removed from the uncured support matrix. Removable embedded 3D printing is advantageous because low-viscosity inks can be patterned in freeform geometries which may not be feasible to create via casting and other printing processes. When printing solid-infill geometries, however, uncured support matrix becomes trapped within the prints, which may be undesirable. This study builds on previous work by formulating a support matrix for removable embedded 3D printing that cures when mixed with the printed silicone ink to solve the problem of trapped, uncured support matrix within solid-infill prints. Printed specimens are shown to have a nearly isotropic elastic modulus in directions perpendicular and parallel to the printed layers, and a decreased modulus and increased elongation at break compared to specimens cast from the ink. The rheological properties of the support matrix are reported. The capabilities of the printer and support matrix are demonstrated by printing a variety of geometries from four UV and addition-cure silicone inks. Shapes printed with these inks range by nearly two orders of magnitude in stiffness and have failure strains between approximately 50 and 250%, suggesting a wide range of potential applications for this printing process.
嵌入式3D打印工艺涉及在支撑基质中挤出油墨，该支撑基质在整个打印和固化过程中支撑油墨。在一类我们称为“嵌入式3D打印”的嵌入式3D打印中，可固化油墨被打印、固化，然后从未固化的支撑基质中移除。可移除嵌入式3D打印具有优势，因为低粘度油墨可以被加工成自由形状的几何结构，而通过铸造和其他打印工艺可能无法实现这种结构。然而，在打印实心填充几何结构时，未固化的支撑基质会被困在打印物中，这可能是不理想的。本研究基于之前的工作，为可移除嵌入式3D打印制定了一种支撑基质，当与打印的有机硅油墨混合时，该支撑基质会固化，以解决实心填充打印物中被困的未固化支撑基质的问题。结果表明，打印的试样在垂直和平行于打印层的方向上具有几乎各向同性的弹性模量，并且与由油墨浇铸而成的试样相比，模量降低，断裂伸长率增加。报告了支撑基质的流变特性。通过使用四种紫外线固化和加成固化的有机硅油墨打印各种几何结构，展示了打印机和支撑基质的能力。用这些油墨打印的形状在刚度上相差近两个数量级，断裂应变在大约50%到250%之间，这表明该打印工艺具有广泛的潜在应用。
