The Wonderful World of Color (Mixing)
When audiences saw The Wizard of Oz in 1939, it was the first time most of them had seen a live-action film in color. Previously, some filmmakers hand-colored frames of film in post-production, but when Dorothy steps out of her house into the magical land of Oz, audiences are treated to about 80 minutes of film using the Technicolor process that captures color while filming. In the same way, Carbon is opening the door to the wonderful world of colored elastomers with EPU 46.
With the release of EPU 46, designers can stop thinking in black and white and achieve their product dreams in full color instead. Before EPU 46, most elastomeric materials were available only in black and maybe one or two other colors. To achieve other colors, parts had to be painted, dyed, or coated after printing, adding another step to the production process. Using pigments, EPU 46 can be tinted to the desired color before printing, saving time and providing color throughout the part, not just on the surface.
Carbon identified the recipes for the 14 colors shown in Figure 2. Each of these colors has a specific formula that dictates how much of each pigment is required as a percentage of EPU 46 Color Base Part A used.
Dreaming of a color not in Figure 2? It may take a little experimenting, but you can mix the tint bases to make your dream color a reality. The options are infinite because all colors are achieved through combinations of pigments added to EPU 46 Part A.
How to Mix Colors
While mixing color into Carbon’s resins is new, the equipment and process are the same as Carbon’s existing production resin mixing process. Carbon introduced and validated bulk mixing options when it started shipping more bulk resin sizes, including 5-L cans. Bulk resin packaging is not only more sustainable because less plastic packaging is used, it is also much more affordable per liter. With certain resins, customers can achieve savings of up to 63% by switching from cartridges to large-format bulk packaging.
Because EPU 46 is available only in bulk, ranging from 5-L to 950-L volumes, the production mixing process is required.
Equipment and Materials Needed (All Mixer Types)
To achieve a uniform color, use a vortex mixer, overhead mixer, or planetary mixer.
- EPU 46 Color Base Part A
- Mixer (vortex, overhead, or planetary)
- Mixing container (based on mixing method)
- Color pigments
Measure out the EPU 46 Color Base Part A, plug that amount into the color formula to determine how much dye is needed, then add that amount using a pipette.
Put the container in the vortex mixer and adjust the counterbalance based on the weight of the container. Start by mixing for 16 minutes and check to see if the resin is uniform in color.
The overhead mixer should include a blade and be attached to a stand to hold the mixer and enable height adjustment. Measure out the EPU 46 Color Base Part A and plug that amount into the color formula to determine how much pigment is needed. Add that amount using a pipette.
Clamp the container to attach it to the stand of the mixer. Set the mixing blade in the container at about ⅓ the height of the resin, then turn it on and adjust the speed so there is a healthy, stable vortex. Start the mixer on low and add speed until you find the balance. Start by mixing for 1.5 hours and check to see if the resin is uniform in color. The time needed to adequately mix depends on how much resin you are mixing and the size of the container.
Measure out the EPU 46 Color Base Part A in a centrifugal mixer cup, plug that amount into the color formula to determine how much dye is needed, then add that amount using a pipette.
Put the container in the planetary mixer and adjust the counterbalance based on the weight of the container. Start by mixing for 10 minutes at 2,000 rpm, then check to see if the resin is uniform in color. Using a clear container makes it easy to check underneath to see if there is a section that is not colored.
Mixing Parts A and B for Printing
Once you mix your pigment with the EPU 46 Color Base Part A, it will be stable for months, so you can prepare a bigger batch of EPU 46 Part A and save it to use as needed over time.
When you are getting ready to print, mix your colored part A with part B, as with other dual cure resins, using the same general procedure for mixing outlined in the preceding sections. From here, the printing process is the same as other dual cure resins.
While this process describes mixing color specifically, the same production mixing equipment and workflow can be used with all of Carbon’s dual-cure materials, unlocking cost savings and sustainability.
No additional post-processing is required to get the desired color, just like the film for The Wizard of Oz.
Differentiate with Color
Now that color is within reach for so many products, there are endless possibilities to apply it. Generate a bicycle saddle with your branded color so everyone watching a race knows it’s yours. Print midsoles in various colors to give your customers the choice to pick a shoe with their favorite color. Easily differentiate similar products by printing them in different colors. Allow customers to choose the color of their printed insoles. No matter the product, color opens up a wonderful world of customization. Just mix in the color and you’re ready to go.