Beam extrusion optimization
As an addition to the recent researches, I am also working on extrusion of beams.
I will research PP and HDPE on 3 different temperatures and 3 different speeds to see what works the most efficient.
With all the samples I will do a deflection test to see if these setting changes the stiffness and quality of the beams.
The extruder runs with a gearbox slowing down the motor with a factor 10. At 50 Hertz, the motor turns 1380 RPM. So the extruder runs at 138 RPM.
I will run the extrusion on 15, 30 and 50 Hertz which results in 41.4, 82.8 rpm and 138 rpm
The temperatures I will use are: 160-170, 180-190, 200-210 for PP and 140-150, 160-170, 180-190 for HDPE
Each test will take 1 hour: resulting in 3*3*2=18 hours of testing.
The tube is use is 2 meters long and 50X50 mm with 4 mm walls.
After many beams extruded I have some new data. All the beams were extruded with the extruder from the picture. And I used metal tubes which I mentioned in the start of the topic. While extruding I put a small wooden block in the tube (loosely fitting) to create a bit of counter pressure, resulting in smoother beams.
I updated the spreadsheet with my findings.
I did also stiffness estimations of all the beams finding higher speed gives more pressure which gives higher density of the beams which gives higher stiffness (E modulus)
Together with the visual qualities I figured that the most ideal settings for the extrusion are:
Temperature: 180 barrel and 190 nozzle
speed: 50 hz-138rpm
Gives an E modulus around 1.0 GPa
Temperature: 160 barrel and 170 nozzle
speed: 50 hz-138rpm
Gives an E modulus around 0.7 GPa
I was running low on material, (yes even in the PP headquarter). So, I did use a recycled PP from the industry. This material got less fluid while heated than the PP shreds I did shred myself. This can result in some variations in my research. How ever, the advised speed and temperature do still count for the extruder I used in the environment I was working
I used this for moment of inertia:
The variations are probably due to my measurement skills, deformation or non-homogeneous beams (although the seem pretty homogeneous)
@timhardex I will but right now it is messy and pretty empty. Will share later that later
@mathijsstroober, you rock ! eventually it’s better to collect this in an google sheet, better suited for follow – ups…
This is fantastic work! I really appreciate the effort that has gone into this!
Will there be any more research done on the remaining types of plastics?
Nice work! Great to have a value for the Young’s modulus. But can you explain how you calculated E from the deflection? I get lost at the moment of inertia.
Also you seem to have different values of E when using different weights, is there some plastic deformation occurring?
could you calculate time required to make per metre or foot of beam for each of the settings
Precious Plastic will probably do further research to see if you can extrude PET.
LDPE beams, would require an extreme amount of plastic bags, something we were not ale to collect in this short amount of time
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