How to print with LW-PLA

How to print with LW-PLA

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?

Input variables

For the filament to expand it is necessary to put a certain amount of energy into the filament. The amount of energy a filament can absorb during printing depends on the length of the hot-zone and the time it takes for the filament to pass through the hot-zone. The longer a filament will reside inside the hot-end, the more energy it can absorb which will increase 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.

  1. Print cubes at a set speed in temperatures varying from 200°C up to 280°C
  2. Measure perimeter thickness of each cube, note temperature with highest expansion.
  3. Print cubes with decreasing steps of flow, using temperature found in step 2.
  4. Find the cube at which perimeter thickness equals nozzle size.

Example – Prusa I3 MK2S

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 1. Print cubes at a set speed in temperatures varying from 200°C up to 280°C

 

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.

So when printing on our Prusa MK2s at 25 mm/s we can print accurate model using 250C and using 30% flow rate. Increasing the speed will be possible however we need to make sure the filament can absorb enough energy, so to account for the short residence time of the filament in the hotend, the temperature should be increased in order to keep the expansion of material the same.

Applications

Lightweight printing

Temperature245-260°C
FlowDown to 35%
Print speedUp 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

On the left we printed the same gcode using regular PLA, on the right our colorFabb LW-PLA showing the expanding properties enabling 0.6mm layerheight from a 0.4mm nozzle.

TemperatureUp to 260+°C
Flow50%
Print speed30-50mm/s
Max layerheight with 0.4mm nozzle0.6mm

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.

Showing 14 comments
  • William Pelletier
    Reply

    I would like to congratulate and thank the Colorfabb company for creating this game-changing material. I have purchased four spools of it so far, and have already used up one. LW-PLA has allowed me to design and create the first truly flyable 3D-printed rubber powered airplane. (You can see it in action at https://youtu.be/2k9LypU1OJI, and see my design on Thingiverse at https://www.thingiverse.com/thing:4127098.)
    You would be interested to know that the LW-PLA settings that I have been successfully using are much different than those you describe in your article. First, I have been printing LW-PLA with an 0.3 mm nozzle. My motivation for doing this was to print thinner walls and save as much weight as possible, but I believe that the smaller nozzle facilitates heat transfer to the filament. Also, most of the parts of my airplane were printed in vase mode at a print speed of 20 mm/s. (In my print settings, 20 mm/s is the speed that the vase mode wall was printed at.) At this low speed, combined with the smaller nozzle, I can print walls that are 0.35 mm thick at a nozzle temperature of 210 C at a flow rate of only 35% with my fan running at 50%. This is a full list of the LW-PLA settings that I used to print my rubber-powered airplane:
    (I started with the default ‘Fine’ profile in Cura. The settings listed below are the ones I changed from the ‘Fine’ profile.)

    Layer Height: 0.12 mm
    Initial Layer Height: 0.24 mm
    Line width: 0.3 mm (same as nozzle diameter for most parts; I used 0.4 mm for one part)
    Wall Thickness (for non-spiralized parts): 0.6 mm
    Top/Bottom Thickness: 0.8 mm.
    Infill density: 20%
    Infill Before Walls: Off
    Print temperature: 210 C
    Build Plate Temperature: 60 C (although I have had this as low as 45 C with good results.)
    Flow: 35% (This is for wall flow, outer wall flow, and inner wall flow)
    Top/Bottom Flow, Infill Flow, Skirt/Brim Flow, Initial Layer Flow: 50%
    Retraction: Off (Note: I think this could be left on, but I did not see a need for retraction for any of these parts.)
    Print Speed: 20 mm/s (for ALL print speeds: wall, infill, top/bottom, etc.)
    Travel Speed: 60 mm/s (for all travel moves)
    Print Cooling: On
    Fan Speed: 50%
    Minimum speed: 7 mm/s
    (In addition to these settings, most of the parts were printed with a 6 mm brim.)
    My printer is an Anycubic Kossel Linear Plus delta printer that was equipped with a Titan-clone extruder. The hot end is an e3d clone with a Teflon lined heat break.

    I believe that your LW-PLA is the most innovative filament that I have seen in the last few years. I hope that you never stop making it. I would be interested to see if you can apply this ‘foaming’ technology to other materials such as ABS or HIPS. These materials are even lighter than PLA, and if you could make LW-ABS or LW-HIPS, it would allow those of us who are making flying models to make them even lighter.

  • Yigal Ringart
    Reply

    Good day!
    Can you please advise how to choose the best material for 3d prints for investment casting?
    can you please deliver your preferred material for this application.
    Thank you
    Yigal Ringart
    CEO
    Exact-tec Israel
    Former CR casting

  • Paul
    Reply

    How about some preferred settings for the Ultimaker 2/2+/3 etc?

    • Team colorFabb
      Reply

      Hi Paul, Depends on what your goal is with the material. In general if you want to go for maximum expansion then you’ll be at the higher range of temperatures, 240-245C. THen you can expect printing with a flow multiplier of around 40%-50% for the Ultimaker systems. Don’t print to fast, it’s best to keep all speeds at 40 mm/s (at 0.2mm layerheight), or slower if you need to transfer more thermal energy to increase expansion / foaming.

      Heated bed can be set to 40-60C.

  • ali
    Reply

    Hello,

    I don’t know where to ask my question. Would you please help me?
    We bought colorfabb xt-cf20. With PLA we did not have any problem printing but for carbon fiber we have. which nozzle diameter should be used for 0.2 mm height and 0.4 mm width? We changed temp to 260. I use creality cr-10.

    Thanks

  • David Jeuniaux
    Reply

    Does the filament bridge well at full expansion ?

  • William Pelletier
    Reply

    I have just purchased two rolls of this filament, and I am looking forward to trying it out. I have a few questions about printing with this filament. Should the part cooling fan be on or off when printing with LW-PLA? Also, do you recommend using an enclosure for printing with LW-PLA? And do you have a recommended print bed temperature for this filament? (I am printing on a heated glass bed lined with a thin sheet of PEI.)

    • Sven Hacken - colorFabb team
      Reply

      The part cooling fan should be turned of if the geometry allows it.
      Due too the expanding taking up energy, the fan is not necessary most of the time.

      An enclosure is not necessary.

      Heated bed temperature of regular PLA: 50-60C should be fine.

  • Julien Pevrol
    Reply

    Hello,

    I am an industrial designer in a french company, and i’m really seduced by this product (LW-PLA).
    I would like to know if you could send me the detailed mechanical properties datasheet of this material (especially young modulus; elastic, plastic and breaking limits) ?

    Best regards.

    Julien PEVROL

    • Team colorFabb
      Reply

      We’ll upload an updated technical data sheet soon.

  • Renato
    Reply

    According to the pictures, the surface finish of this filament looks a lot better than regular PLA. It looks like you can hardly identify the layers, can you confirm this?

    • Sven Hacken - colorFabb team
      Reply

      The layers are indeed less visible and it gives a kind of SLS look to the printed parts.

  • Josef Kamir
    Reply

    please give me your LE-PLA safety data sheets
    josef kamir tel Aviv University
    thank you
    israel
    yosikk@gmail.com

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