Extruding PP from recycled plastic from ocean
I am extruding PP plastic we got from a company gathering plastic from the ocean. I do not have a datasheet or any other material information. Does anyone have experience with extruding PP? What are good temperature to use?
I was trying it for 2 days with temperatures around 170-180 degrees, but I can't manage to fine tune it to have a consistent thickness.
HDPE from the same company was working very nice.
Thank you for any advice
Great Idea. Love to know more about where and how the company is collecting.
It looks like the filament is coming out with a "like" drawn or pulled effect. So it looks like the crsytalisam of the plastic is not homogeneous.
I was having the same issues with HDPE the other day with Contaminated materials, that I think had other plastics in the shred and not only HDPE. So I would double check if it is only PP. (I have no idea how to check that).
https://en.wikipedia.org/wiki/Polypropylene Note the comments on "thermal properties". It looks like you're temps are in the right range.
Just some thoughts, Adrian
@adrian Thank you for your reply!
Can you please tell me your temps for HDPE?
Currently I am using H1 - 170
H2 - 175
H3 - 180
H4 - 185
But yes, I think you are correct. Plastic is contaminated, even if I just look at the pellets, I can see stripes which I am not sure are just from different color...
I would very much like to extrude filament even though it might be mixture, do you think its possible? It might not be pure PP.
This is the company we are collaborating with: https://www.ogoori.eco/
For 2mm Rpm 5, H 4- 165, 3-170, 2- 170, 1- 165. Fan at 30% for HDPE.
But if you have seen my other posts, I am still planning to play with the Temps. But it works so far.
What is your reason for the low RPM?
You could also try to sort out a few handfuls of pallets from the "striped" ones to the solid green, then only use only one colour to extrude X meters then put in the other colour and see if it has any effects.
I meant to ask, are you making this for use in a 3D printer?
Thank you for your temperatures!
I forgot to write, yes, I am extruding 1,75 mm for 3d printing.
I was lowering rpm because wheels next to the thickness sensor were squeezing it too much = it wasn't cooling down fast enough. When I lowered rpm, it started to work.
It's really good idea with sorting out. But for 3D printing you need very good quality. Today I started mixing 50% of raw PLA granules from 3Devo and 50% of recycled PP, and it's working like charm! Results are a bit transparent from PLA, and it's not purely recycled material, but it's working. I am running it on:
rpm 3.0 H1 170, H2 175, H3 180, H4 170, fan 100%
Thank you both very much for participating in this discussion 😊
It is always a pleasure to see two friendly users that share a common goal and help each other.
I will do my best to contribute here.
First, I can say that this guide applies to PP in the same way it does to HDPE.
There might be several issues in your case :
- ovality due to crystallization (see article above). This complementary article (not PP-specific) can help
- incomplete melting
- bad texture
- contamination. Difficult to say, given the color of the base pellets. Running a DSC characterization test would be interesting, but you perhaps do not have access to that technology ?
- the grade is perhaps just not compatible with this extrusion process. One of the criteria is explained here in a simplified way. Do you have a Technical Datasheet ?
- non-optimal settings. Most of our articles explain how certain issues are connected to settings adjustments. Unfortunately, most of it comes down to just testing different parameters and trying to observe trends. I can help you with that if you send me a datalog and more pictures/videos 😉 For PP, in general, the thermal window is 160-210°C, and the RPM window is 2.0-6.0. The fancooling depends on your room temperature
I know this can be quite overwhelming. Your material is very tricky, but I am sure we can isolate, understand the issues one by one. If you keep me up to date with your results, I will help you analyze the experiments.
Please let me know if anything is unclear