Extrusion of LDPE/HDPE

Share you advice here:
LDPE/ HDPE?
What model extruder are you using?
Extruder aperture size?
What temperatures are you using?
Filament extruded per minute?
Filament diameter variation?
Any other advice?

KarlS wrote:Share you advice here:
LDPE/ HDPE?
What model extruder are you using?
Extruder aperture size?
What temperatures are you using?
Filament extruded per minute?
Filament diameter variation?
Any other advice?  

Hi Karl,

In Thomastown, we use a Filastruder. We typically operate it with a nozzle of 2.5-3mm, to reduce the pressure in the system, preventing back flow and clogging of the augur, where it will solidify and is too far from the heating element to melt, requiring a disassembly and therefore a long clean. The size of the nozzle is less important, compared to the rotational speed of the winder, as a fast speed will make it thinner, and a slower speed will make it thicker.

The temperature is dependent on what material you are putting through the Fildastruder, but we have found that LDPE extrudes well at 140-150 degrees Celcius, wheras HDPE extrudes well at 180-190 degrees Celcius.

I cannot say exactly how much we can produce per minute, but we can comfortably produce a full roll of filament every day.

The diameter variation we can get ranges from 1.6-1.8mm. We have been working on reducing the variance and are currently trialing a new system which we believe will have positive results.

My advice to you would be to frequently monitor the filament production process, and adjust the speed of the winder frequently to try and produce as much filament as possible. When experimenting with temperatures, keep in mind the location of the thermocouple near the nozzle, and the temperature around the walls of the heating element may be higher. Therefore, research what the burning point of the plastic is, and give yourself considerable room to compensate for this circumstance.

Also, keep in mind that every different type of bottle-cap will have a different characteristic. For instance, two different HDPE bottle-caps will have different material properties. When making filament, try not to make it comprised of different types of bottle-caps. Separate the HDPE caps based on the sources, and granulate and extrude them separately.

Granulate the bottlecaps and try and keep the particle size consistent, so that you can get an even melt.

Keep in mind, the filastruder can only produce results which are so good, and therefore you will have to do a lot of tinkering and modification to it. Hopefully in the future, we may be able to produce filament on industry grade equipment in the near future.

Hi Adolph L,

On the Filastruder we have in Maryborough, we have only on/off switch as a control for the auger.
I wasn't aware of any auger speed control setting.
Can you tell me how to adjust the auger speed on the Filastruder?

I was talking about the winder, not the filastruder.

We don't have a winder at Maryborough, can you get some one to send us one?

based on your figures your filament production estimate is:

meters per Day 330
meters per hour 8 41.25
meters per minute 60 0.6875
meters per second 60 0.011458333
centimeters per second 1.145833333


I didn't think it was so difficult to measure ~1 cm per second, I thought the winder would have output info like that.

The winder is just a motor which turns a wheel, the faster you make it spin, the more it stretches the fillament and thins it out, alternatively, the slower you let it spin, the thicker the fillament.

How did you go with the HDPE filament manufacture .? I need to be able to 3D print approx A4 size sheets around 4 mm thick with holes in them . The LDPE is too soft so need stiffer compond. Was it difficult to print with the HDPE ,as compared to PLA. ?