Transparent plastic is nothing new. However, 3D prints are usually opaque or–at best–translucent. [Thomas Sanladerer] wanted to print something really transparent. He noticed that Colorfabb had an article about printing transparent pieces with their HT filament. [Thomas] wanted to try doing the same thing with standard (and cheaper) PETG, which is chemically similar to the HT. Did he succeed? Watch the video below and find out.
You can get lots of clear plastic filament, but the process of printing layers makes the transparency turn cloudy, apparently mostly due to the small gaps between the layers. The idea with the HT filament is to overextrude at a high enough temperature that the layers can fuse together.
[Thomas] wanted to create some clear parts and diffusers for lamps. The diffusers print using vase mode and the lamps he creates when them look great even without clear diffusers.
His first experiments involved layer height and extrusion rates. He tried to determine what was making things better and worse and modifying his technique based on that. There were also some post-processing steps he tried.
If you want to see what the Colorfabb HT parts made by someone other than Colorfabb look like, check out the second video below from [3D Printing Professor]. The prints he is making don’t look very clear until he does some post processing. Even after the post processing, it isn’t going to fool anyone into thinking it is glass-clear. However, the parts that Colorfabb shows on their blog post about the material do look amazing. Between the overextrusion used to prevent gaps and the post processing steps, [3D Printing Professor] warns that it won’t be easy to get parts with precise dimensions using this technique.
There are 3D printing filaments out there with a lot of interesting properties. Whether it’s the sanded-down MDF feel you get from Laywood, the stretchy and squishy but somehow indestructible feel of Ninjaflex, or just regular ‘ol PLA, there’s a filament out there for just about any use. Even optically clear printed objects. Yes, you can now do some post-processing on printed parts to make T-glase crystal clear.
The big advance allowing translucent parts to be made clear is a new product from Smooth-On that’s meant to be a protective and smoothing coating for 3D printed objects. With PLA, ABS, and powder printed parts, this coating turns objects shiny and smooth. Strangely – and I don’t think anyone planned this – it also has the same index of refraction as T-glase. This means coating an object printed with T-glase will render the layers invisible, smooth out the tiny bumps in the print, and turn a single-walled object clear.
There is a special technique to making clear objects with T-glase. The walls of the print must be a single layer. You’ll also want a perfect layer height on your print – you’re looking for cylindrical layers, not a nozzle that squirts out to the side.
The coating for the pictures above was applied on a makeshift lathe built out of an electric drill and a sanding pad. This gave the coating a nice, even layer until it dried. After a few tests, it was determined lenses could be printed with this technique. It might not be good enough for 3D printed eyeglasses, but it’s more than sufficient for creating windows for a model, portholes for an underwater ROV, or anything else where you want nothing but light inside an enclosure.