Programmable color filament (thermochromic)

Description

Multi-color 3d printing is hard
Imagine the possibilities for 3d printing multi-color objects using a stock 3d printer with no hardware modifications whatsoever. This might seem like a pipe dream but we are here today to explore this exciting development.

Today's options for multi-color printing require many modifications to machine hardware and software. Multiple print-heads / tool changes, manual human spool swaps or automated filament splicing machines are currently required to produce multi-color 3d printed objects.

The method and material explored here allows for software controlled color changes with stock 3d printers requiring no hardware modifications.

More info can be found here
https://www.autodrop3d.com/programmable-filament.html

Details

How it works?

There are some thermochromatic materials that allow for the color to be set in a stable way allowing for a persistent change in color after the material is heated beyond a particular set point. An example of this property can be seen in erasable pen products. Erasable pens use heat generated by friction to make the ink transparent. To make the ink visible again all one has to do is freeze the paper and the color will be restored to the ink.

The thermochromatic materials we are using have two temperatures that trigger a color change. One is below freezing and the other is within the printable temperature of the particular plastic being used. This makes it possible to print the material and selectively change the color of portions of the print just by changing the temperature of the hot end.

Intellectual property disclosure.

A provisional patent has been created for this to prevent other larger entities from locking down the IP. We are seeking a filament manufacturer to work with and try to bring this to market.

Project Logs

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Proof of concept material produced with the help of ProtoPasta
mmiscool • 09/19/2021 at 04:13 • 0 comments

We worked with protopasta to get a test run of the material made and tested. We were using a low temp PCL plastic to produce the filament. This stuff is really sticky.
This first batch did not have the high contrast we were after but that is just a matter of increasing the amount of the thermochromatic additive
Watch Joel's video to see some of the difficulty and the first successful print with the crazy stuff.
You can see where the print tempature was changed. When this was printed the bottom layers were printed at the higher temperature turning the pigment "off" and the raised bat symbol was printed at a lower temp that would melt the plastic but not deactivate the pigment.
Look at these sexy action shots of the filament extruder at protopasta. It was weird for them to run the machine at such a low temperature so there was a bit of a learning curve and had to run the extrusion much slower than there normal PLA based materials.
Spooling up all that sweet sweet thermochromatic filament while checking the diameter.