Coloring In 3D Printing
Whether you’re the type to print in color or paint your print, giving life to your 3D model can be a challenging task. That’s not to say there aren’t many options available.
Many are already familiar with multicolour (or multi material) 3D printing: the process in which the printer's hot end can either extrude one of the input materials alone, or a mix of two or more input filaments by spreading out the feed speed between extruders.
This allows you to theoretically create any color under the rainbow with a machine that can hold enough filament. The bad news is that in practice the technology isn’t quite ready to make such precise pigment changes without wasting a considerable amount of material while clearing the hot nozzle for the next colour change.
However, there are still ways to achieve these beautiful gradients and life-like textures in 3D printing. Here is an introduction to just a handful of them.
Employing a powder/binder jet process, 3D systems has one of the oldest and well regarded full color 3D printing processes. An inkjet system traverses a flat bed of powder, dropping liquid binder selectively – and the binder is colored in the same way as 2D inkjets. As a result, they can progressively build up a full-color object. However, colors aren't as brilliant as they could be, prints aren't always the best resolution, and clear material isn't viable on their system.
Stratasys brings forward their J750 PolyJet technology. This was the culmination of their PolyJet development, which is a method that combines inkjet photopolymer resin deposition with UV light exposure. Their most recent method consists of seven distinct resins that may be dynamically blended to produce practically any color, including a clear substance. Their color 3D prints are stunning and, in some cases, extremely realistic. One of their only drawbacks is the cost of purchasing and maintaining their system, making it difficult for most businesses to afford.
HP has adapted their powerful Multi Jet Fusion (MJF) technology to generate full color 3D prints, making them one of the newest players to the color 3D printing sector. The voxel-level control provided by MJF is the key to their color capacity. In MJF, an inkjet mechanism can deposit up to eight agents per voxel. These are liquid droplets with a wide range of features. You might have agents that bind the material together, construct support structures, produce electrical conductivity, and, lastly, blend CYMK inking chemicals to create colors. HP's MJF systems can print complete color textures thanks to agents and voxel-level control: color gradients may be modified voxel by voxel, just like is done with pixels on 2D color systems.
Mimaki's process is similar to Stratasys' in that it is based on resin. Mimaki, on the other hand, has a long history of producing large-scale 2D print systems for industry. Their knowledge of color in general has transferred well into their 3D printing method, which boasts of the capacity to properly replicate hues. It works because the Mimaki samples are so lifelike. They could be offering one of the best color prints available to date. While their pricing is actually lower than Stratasys', it remains at levels that may prevent some businesses from affording it long term.
CleanGreen3D's, previously Mcor Technologies, approach is perhaps the most unusual of the bunch, as they use ordinary paper as their raw material. At each paper layer, a sharp CNC-controlled blade slashes the object's edge. After printing, the machine glues each paper sheet together to form an item, which is then released by removing the cut pieces. To create color they use an inkjet technique to pre-print each sheet of paper before sending it in for gluing and cutting. Where the cut is to be made, the inkjet prints a few millimeters of the appropriate color. When you stack the sheets together, you'll obtain a fully colored object. It is not possible to use clear material and the color quality isn't quite as outstanding as the other processes, but the CleanGreen3D system is less expensive, especially true for their material: paper.
Quality, material and functionality are variables to be considered with each of your printing projects. Sometimes you may need to sacrifice one due to your budget. Whatever the case, many coloured prints have pros and cons that should be taken into account.