Interested in dying your printed parts black? Follow the simple instructions below to produce beautiful, black parts!
Materials: Rit dyes are widely available in many brick-and-mortar and online stores; they are available in 26 colors which can be combined to create hundreds of custom shades and hues.
Procedure: (a simplified version of the procedure published on the Rit Studio web page):
- Read the precautions on the dye box or bottle to prevent accidental staining of your clothing, furniture or body.
- Soak your printed part in warm water for 1-24 hours.
- Take a sturdy polyethylene food freezer bag and place it in a plastic or glass container for easy handling. Dilute the liquid Rit dye with a very hot water in an approx. 5:1 ratio in a plastic bag and stir it well. Water temperature should be between 60oC and 80oC (140oF-176oF), since the dye diffusion into the nylon is accelerated at higher dye concentrations and temperatures.
- Place a water-presoaked printed part in the bagged solution for 5 to 15 minutes; make sure the part is completely immersed in the liquid. Stir it mildly from time to time to ensure good dye distribution. If the solution cools down significantly, place the bag with a solution and the part (but not those reinforced with carbon fiber!) in a plastic, glass or ceramic cup or container and microwave it for 2-4 minutes (try not to boil the solution!)
- Carefully remove the dyed part from the solution and rinse it for a few minutes in warm water until the excess dye is washed away. Dry the part with a paper towel and let it dry in the air.
Nylon (polyamide) polymers are one of the easiest to dye synthetic polymers. due to their polar, hydrophilic nature and a large concentration of the -NH-CO- (amide) groups.
Thermo-mechanical properties of the 3D printed parts measured by mechanical testing and DMA (Dynamic Mechanical Analysis) were found to change very little, if at all, after dying under the conditions described above. This is because the dye diffuses in only a very thin (0.1-0.2 mm) external layer of the part. This is readily verified by slicing a corner or a protruding part with a razor blade and checking the cross-section under a microscope.
Historical Note - Lacrosse heads are sold white so players can customize them with Dye.
* Polyamides are best treated in acid dyes, that is, dyes using acidified water solutions. There are hundreds of such dyes available in any colors imaginable and many published procedures and recipes to use them.