Custom Technique for Blending Filament Colors in 3D Printing
Scientists at Western University have developed a groundbreaking technique for creating custom colors in 3D printing filament, leveraging the Kubelka-Munk theory and open-source software. This method promises to deliver unique hues unavailable in any commercial filament.
The team began by preparing eight different color samples of 3D print waste and measuring their spectral reflectance properties using a visible-light spectrometer. These findings were fed into SpecOptiBlend, an open-source program that optimizes pigment blends to match target colors. The software prefers subtle color differences perceived by the human eye, relying on the Kubelka-Munk theory, typically used for calculating paint mixtures.
By inputting the spectral data and target color into SpecOptiBlend, the program calculates the optimal blend of waste plastics, which, when extruded into a filament, closely resembles the desired color. Despite its potential, this process may not be imminent for consumer 3D printers, as it requires accurate measurements of the filament's optical properties, obtained through a spectrometer.
To facilitate this method for a broader audience, the researchers propose that filament manufacturers make public the properties of their filaments, allowing consumers to mix filaments to create custom colors.
This technique calls to mind another approach that treats filament like paint to achieve remarkable color effects. Additionally, the team encourages exploration of filament extruders for those interested in attempting this method.
For those interested, here's a step-by-step guide to replicate the process:
- Collect pigments and base clear or white filament resin.
- Measure the reflectance spectra of each pigment, the base resin, and the target color using a spectrophotometer.
- Learn the basics of the Kubelka-Munk theory and calculate the absorbance and scattering coefficients.
- Prepare reflectance spectra files in a format accepted by SpecOptiBlend.
- Use SpecOptiBlend to optimize the pigment ratios for the target color, considering constraints such as minimum and maximum pigment loadings and total pigment concentration.
- Validate the results by creating test filaments, measuring their reflectance, and adjusting the formula for better color consistency.
This open-source software, SpecOptiBlend, can be utilized to create custom colors in 3D printing filament, emulating the Kubelka-Munk theory typically used for paint calculations. This lifestyle-altering technology encourages filament manufacturers to publish the properties of their filaments for consumers to mix them, achieving personally tailored colors in their 3D prints.
