1 Topic by wahada (edited by wahada 2014-11-19 21:51:58)

  • wahada
  • Member
  • Offline
  • Registered: 2014-02-03
  • Posts: 60

Topic: Acetal Filament Extrusion

Hi All,

I extruded some acetal filament today with some success. First of all I want to make clear that I am doing this for use in injection molding and do not intend to use this acetal for 3D printing.  I bought a few pounds of acetal pellets from an eBay seller who stated that they were for injection molding. I tried to get more information from him on the pellets after the purchase but I got no response. I made some guitar picks from the natural resin pellets and they came out very nice.
Today I added 5% Blue Pearlescent dry pigment to the pellets and mixed well by shaking and turning the container.
I started out extruding at 185 degrees and the filament was very porous due to decomposition and gassing of the acetal polymer.  I gradually backed the temperature down to 168 degrees and the gassing of the acetal stopped. The shape of the filament is a very odd pear-shape as you can see in the photo. I used the 3mm nozzle and the filament at the widest point is about 2.50 mm to 2.6 mm wide. The Filawinder wound it on the reel  just fine. I think that the air blowing from the cooling fan is causing the odd shape. It almost looks like the filament flattened out and folding in on itself as there is a hole in the center.
I stopped the cooling fan at one point and the filament really stretched out terribly. Maybe try to go even lower with the temperature next run? In spite of the odd shape it pelletized well and the color seemed very evenly dispersed. The pellets are very usable and I will try to make some picks from them tomorrow.

https://truck.it/p/_B0dRBB3KL
https://truck.it/p/ZDZP2nNJUh

Post's attachments

Blue acetal filament.jpg 285.53 kb, file has never been downloaded. 

Blue Acetal Pellets.jpg
Blue Acetal Pellets.jpg 398.04 kb, file has never been downloaded. 

You don't have the permssions to download the attachments of this post.

2 Reply by fredaxe

  • fredaxe
  • Member
  • Offline
  • From: SOUTH OF FRANCE
  • Registered: 2014-01-20
  • Posts: 111

Re: Acetal Filament Extrusion

hi  wahada
nice try
what 's pigment  do you use ? link ?
thx
fredaxe

3 Reply by wahada

  • wahada
  • Member
  • Offline
  • Registered: 2014-02-03
  • Posts: 60

Re: Acetal Filament Extrusion

Hello fredaxe !

The dry pigment is from eBay, here is the link:

http://www.ebay.com/itm/Brilliant-Blue- … mp;vxp=mtr

The picks do not have that "pearlescent" finish which I expected but the color is OK. Maybe the flat pearl flakes got ground up in the filastruder to a smaller size? Or the milky white acetal resin mutes the pearl sheen? I don't know.
I am just happy that I was able to extrude and pelletize the acetal successfully. I am going to try some " Glow-in-the-Dark" pigment powder next. I will post those results.

Post's attachments

Blue Acetal Guitar Picks.JPG
Blue Acetal Guitar Picks.JPG 2.11 mb, file has never been downloaded. 

Brilliant Blue Pearl Pigment.JPG 512.42 kb, file has never been downloaded. 

You don't have the permssions to download the attachments of this post.

4 Reply by Ggalisky

  • Ggalisky
  • Ggalisky
  • Member
  • Offline
  • From: California
  • Registered: 2014-05-21
  • Posts: 487

Re: Acetal Filament Extrusion

Really cool! Keep us posted up about your ventures with the Glow in the dark pigments.

Ulitmaker 2, a few repraps, Custom Big FFF 3D printer with heated chamber.

My Blog http://ggalisky.weebly.com/
My Youtube https://www.youtube.com/channel/UCXShYo … aDUpebDAOw

5 Reply by AndersE (edited by AndersE 2014-11-24 20:24:41)

  • AndersE
  • Member
  • Offline
  • From: Sweden
  • Registered: 2014-07-20
  • Posts: 83

Re: Acetal Filament Extrusion

I think this is the same pearls that are for spraying cars. Paintwithpearl.com has all these different pearls, chameleons, flakes etc..

I tried this a while ago in ABS. But you have to have a lot of powder mixed in to really get any color or effect.
Remember that when used in carpaint you spray a thin layer on top of the base color to get the effect, so all pigment is concentrated in a thin layer on top.
Mixing with pellets and extruding you mix INTO the plastic. So very little is seen on the outside of the filament.

Also, a blue pearlescent should be ontop of preferrably a white base not blue to get that shimmering effect.

wahada wrote:

Hello fredaxe !

The dry pigment is from eBay, here is the link:

http://www.ebay.com/itm/Brilliant-Blue- … mp;vxp=mtr

The picks do not have that "pearlescent" finish which I expected but the color is OK. Maybe the flat pearl flakes got ground up in the filastruder to a smaller size? Or the milky white acetal resin mutes the pearl sheen? I don't know.
I am just happy that I was able to extrude and pelletize the acetal successfully. I am going to try some " Glow-in-the-Dark" pigment powder next. I will post those results.

6 Reply by wahada

  • wahada
  • Member
  • Offline
  • Registered: 2014-02-03
  • Posts: 60

Re: Acetal Filament Extrusion

Thanks for the info AndersE. Maybe just dusting the inside of the mold before injecting might be better? I will try that sometime. Have you ever tried the Glow-In-The-Dark pigments with ABS or any other resin?

7 Reply by paretz

  • paretz
  • Newbie
  • Offline
  • Registered: 2015-02-18
  • Posts: 3

Re: Acetal Filament Extrusion

I am testing Acetal as well and continue to get the flat ribbon filament, hotter, colder with and without the fan, anyone comes up with a way to control this please let me know!

Also I Injection mold Acetal (Delrin) all the time if you need assistance with your project.
Thanks,
Pete