At colorFabb material development never stops. We’re starting the 2019 with a fascinating new material, first of its kind in FFF 3D printing materials.
We’re proud to announce, colorFabb LW-PLA. This filament uses an active foaming technology which is triggered by temperature. At it’s peak the filament will expand nearly 3x it’s volume, meaning users can decrease flow by 65% to obtain lightweight parts, or use the expanding properties to speed up print time by using big layer heights or single extra thick perimeters.
colorFabb LW-PLA is available in two colors, natural and black. The foaming also gives printed parts a rough matte surface finish, which makes parts look very appealing.
HOW DOES IT WORK?HOW DOES IT WORK?
This material is based on our unique PLA/PHA recipe which means that it will print very similar to our other PLA/PHA materials. We’re sure most will be able to dial in settings in no time, but we still thought a write-up on print settings is interesting to share. If you have great tips or slicer settings please share! email@example.com
Assuming nozzle size and layerheight are fixed, our main input variables are Temperature, speed and flow to determine the amount of expansion.Assuming nozzle size and layerheight are fixed, our main input variables are Temperature, speed and flow to determine the amount of expansion.
HOW TO DETERMINE THE EXPANSION OF THE FILAMENT
If you want to print lightweight parts which are dimensonally accurate, it’s important to first determine the possible expansion of the material. This can be done by printing single perimeter test cubes without top and bottom layers. We use the following 4 step process to determine the maximum expansion at a certain speed, temperature and flow.
PRINT CUBES AT A SET SPEED IN TEMPERATURES VARYING FROM 200°C UP TO 280°C
MEASURE PERIMETER THICKNESS OF EACH CUBE, NOTE TEMPERATURE WITH HIGHEST EXPANSION.
PRINT CUBES WITH DECREASING STEPS OF FLOW, USING TEMPERATURE FOUND IN STEP 2.
FIND THE CUBE AT WHICH PERIMETER THICKNESS EQUALS NOZZLE SIZE.
Normally we don’t like to do post processing of any of our prints, they should look awesome straight of the printer. For bronzeFill we’re happy to make an exception, since it will elevate your models to another level when polished. Here we’ll document the various methods of post processing the 3d prints. We’re a little out of our depths here so we’ve been seeking help from the active community of makers.
First what you want to do is sand your model with a fairly rough grit of sand paper, something like 220-240 should work nicely. BronzeFill is much easier to sand down then regular PLA, so depending on your model this shouldn’t take too long. By increasing the grit of the sand paper the model will get smoother everytime, exposing the bronze particles at the surface, but it will still look matte and dull.
2. Steel wool
This tip came in from Paul Braddock, a talented character modelling artist and active member of the Ultimaker community. He used steel wool to polish the surface which will start exposing the bronze particles even more. We’ve tried this method with a fairly fine grade of steel wool and were impressed how shiny it already got!
3. Making it Shiny!
Now that the layers are sand down and the bronze particles are already shining a bit on top of the surface it’s ready for the next step. Now this is were it becomes really interesting, since there are so many methods of making bronze shiny. We used a copper polish which gave nice results. It was applied with a dry towel making small circular movements and applying light pressure, then we used another side of the towel to get rit of all the polishing paste.
Apart from polishing the material to make it more shiny one can also apply products to create a patina look. We haven’t been able to try this personally but Paul Braddock did. This is what he was able to create with an antigue Patina, it looks stunning.
Down to 35%
Up to 40mm/s
Lightweight printing can be done by using the settings determined in the paragraph above. Keep in mind that if the flow is decreased to low values the hot-end might clog due to the filament expanding before exiting the nozzle.
LARGER LAYER HEIGHTS
Up to 260+°C
Max layerheight with 0.4mm nozzle
Due to the expanding behavior of the material it is possible to 3D print with larger layer heights the nozzle itself, this means short build times for quick draft models.
The infamous torture test by Make, printed on the Ultimaker Original. Slight stringing which might be solved with a adjusted retraction settings.
EXAMPLE – PRUSA I3 MK2S
STEP 1. PRINT CUBES AT A SET SPEED IN TEMPERATURES VARYING FROM 200°C UP TO 280°C
Print speed – 25mm/s Part cooling – 0% Printing temperature – 200°C to 280°C in steps of 10°C. Layer height – 0.2mm Nozzle diameter – 0.4mm
STEP 2. MEASURE PERIMETER THICKNESS OF EACH CUBE, NOTE TEMPERATURE WITH HIGHEST EXPANSION.
Cube at 200C – no expansion of material.
Cube printed at 250C – perimeter measured at 1.05mm, which yields a 260% increase of perimeter thickness. Between 240-250C the expansion of the filament was highest.
STEP 3. PRINT CUBES WITH DECREASING STEPS OF FLOW, USING TEMPERATURE FOUND IN STEP 2 (IN OUR CASE 250C).
STEP 4. THE CUBE WITH THE PERIMETER THAT EQUALS THE NOZZLE DIAMETER IS THE LOWEST USABLE FLOW. EXPECT FLOWS AROUND 35-50%.
In our case we found the cube with 30% flow to be equal to the nozzle size.