Ed and I have been building with PCL, which is easy to work with and produces OK results. But Vik has been having lots of success with PLA. It looks as if we can get a supply of 3mm PLA filament (details follow), so should we switch to PLA as the recommended RepRap polymer (not to exclude others, of course)? Being both bio-sourced and bio-degradable it has good green credentials too (cue comments about world grain prices and biofuels... No. We all know that argument. So let's not rehearse it here.) Technical pros and antis? https://reprap.org/forum/read.php?70,10542,10542#msg-10542 Sun, 19 Apr 2026 23:29:33 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?70,10542,11991#msg-11991 https://reprap.org/forum/read.php?70,10542,11991#msg-11991 Forrest Higgs Plastic Extruder Working Group Wed, 14 May 2008 22:53:21 -0400 https://reprap.org/forum/read.php?70,10542,11987#msg-11987 https://reprap.org/forum/read.php?70,10542,11987#msg-11987
Vik :v)]]> VikOlliver Plastic Extruder Working Group Wed, 14 May 2008 21:42:00 -0400 https://reprap.org/forum/read.php?70,10542,11974#msg-11974 https://reprap.org/forum/read.php?70,10542,11974#msg-11974 Well Plastic Extruder Working Group Wed, 14 May 2008 15:46:22 -0400 https://reprap.org/forum/read.php?70,10542,11973#msg-11973 https://reprap.org/forum/read.php?70,10542,11973#msg-11973 Well Plastic Extruder Working Group Wed, 14 May 2008 15:45:32 -0400 https://reprap.org/forum/read.php?70,10542,10910#msg-10910 https://reprap.org/forum/read.php?70,10542,10910#msg-10910
i think you're right - good adhesion is a temperature vs. fluidity-theme.

When the surface of the outputted tray cools down (with smaller diameters faster then with thicker trays) or you set it down on a cold surface, the (cooled down) skin or thermal shock would prevent a proper fusing ...

Viktor]]> VDX Plastic Extruder Working Group Thu, 10 Apr 2008 03:46:07 -0400 https://reprap.org/forum/read.php?70,10542,10904#msg-10904 https://reprap.org/forum/read.php?70,10542,10904#msg-10904
PLA is much more runny and sticky, and fuses so completely I can't imaging being able to break that apart.]]> nophead Plastic Extruder Working Group Wed, 09 Apr 2008 16:21:16 -0400 https://reprap.org/forum/read.php?70,10542,10903#msg-10903 https://reprap.org/forum/read.php?70,10542,10903#msg-10903 redskinsjbs Plastic Extruder Working Group Wed, 09 Apr 2008 16:11:55 -0400 https://reprap.org/forum/read.php?70,10542,10900#msg-10900 https://reprap.org/forum/read.php?70,10542,10900#msg-10900
Bruce]]> brucew Plastic Extruder Working Group Wed, 09 Apr 2008 13:37:52 -0400 https://reprap.org/forum/read.php?70,10542,10899#msg-10899 https://reprap.org/forum/read.php?70,10542,10899#msg-10899
Demented]]> Demented Chihuahua Plastic Extruder Working Group Wed, 09 Apr 2008 12:10:54 -0400 https://reprap.org/forum/read.php?70,10542,10897#msg-10897 https://reprap.org/forum/read.php?70,10542,10897#msg-10897
You can make objects with PLA, HDPE and ABS with a sparse fill and they are still strong, which is good because it saves plastic, speeds up the build and seems to reduce warping. PCL is not really strong enough for that.

Stringing is a bit worse with PLA I think, ABS is best in this respect.

If you need anything high temperature or slippery then HDPE is good if you can tolerate more warping, but it stretches the extruder temperature wise.

ABS is pretty good as well, it handles higher temperatures than PLA but inter-layer adhesion is not as good. That may be beneficial for using it as its own support material though.]]> nophead Plastic Extruder Working Group Wed, 09 Apr 2008 08:54:29 -0400 https://reprap.org/forum/read.php?70,10542,10767#msg-10767 https://reprap.org/forum/read.php?70,10542,10767#msg-10767
Do you ave a sacrificial pasta machine to fill with hot-melt glue?

Vik :v)]]> VikOlliver Plastic Extruder Working Group Thu, 03 Apr 2008 17:50:16 -0400 https://reprap.org/forum/read.php?70,10542,10758#msg-10758 https://reprap.org/forum/read.php?70,10542,10758#msg-10758 [users.adelphia.net]

Speaking of PLA, the local grocery stores have just now started to sell food in containers made of it. So if anyone wants to try some PLA extrusion tests, try your local grocery store.

On filament extrusion, instead of extruding a round filament, why not extrude a flat sheet through something like a heated pasta roller. This might yield a more uniform bubble free filament than could be achieved with a round extrusion. Only problem is that it might require some modification to the extruder.]]> Gene Hacker Plastic Extruder Working Group Thu, 03 Apr 2008 11:46:01 -0400 https://reprap.org/forum/read.php?70,10542,10707#msg-10707 https://reprap.org/forum/read.php?70,10542,10707#msg-10707
They have a number of different 3mm filaments on offer. A current price list is available at [www.carrgroup.co.nz]]]> reece.arnott Plastic Extruder Working Group Mon, 31 Mar 2008 01:31:09 -0400 https://reprap.org/forum/read.php?70,10542,10686#msg-10686 https://reprap.org/forum/read.php?70,10542,10686#msg-10686
Vik :v)]]> VikOlliver Plastic Extruder Working Group Sat, 29 Mar 2008 17:27:45 -0400 https://reprap.org/forum/read.php?70,10542,10680#msg-10680 https://reprap.org/forum/read.php?70,10542,10680#msg-10680
Those UK prices make my hair stand on end. ::o

It's not hard to understand why Adrian wants a granule-fed extruder when you look at them. I'd feel the same way.]]> Forrest Higgs Plastic Extruder Working Group Sat, 29 Mar 2008 11:58:18 -0400 https://reprap.org/forum/read.php?70,10542,10672#msg-10672 https://reprap.org/forum/read.php?70,10542,10672#msg-10672
Not that the price of welding rod is very good compared to raw plastic. My 5KG of HDPE was about ]]> nophead Plastic Extruder Working Group Sat, 29 Mar 2008 05:46:48 -0400 https://reprap.org/forum/read.php?70,10542,10669#msg-10669 https://reprap.org/forum/read.php?70,10542,10669#msg-10669
The biggest problem with PCL is the cost of doing a second run due to minimum quantities.

If the demand was there then the price would fall at least by 50% but you would need to be talking tonnes not kg, usual commercial supply & demand dilemma.]]> Ian Adkins Plastic Extruder Working Group Sat, 29 Mar 2008 05:31:26 -0400 https://reprap.org/forum/read.php?70,10542,10659#msg-10659 https://reprap.org/forum/read.php?70,10542,10659#msg-10659 Forrest Higgs Plastic Extruder Working Group Fri, 28 Mar 2008 21:54:53 -0400 https://reprap.org/forum/read.php?70,10542,10655#msg-10655 https://reprap.org/forum/read.php?70,10542,10655#msg-10655
So do you know of a supplier in the US?]]> redskinsjbs Plastic Extruder Working Group Fri, 28 Mar 2008 19:06:39 -0400 https://reprap.org/forum/read.php?70,10542,10650#msg-10650 https://reprap.org/forum/read.php?70,10542,10650#msg-10650 Forrest Higgs Plastic Extruder Working Group Fri, 28 Mar 2008 15:29:06 -0400 https://reprap.org/forum/read.php?70,10542,10649#msg-10649 https://reprap.org/forum/read.php?70,10542,10649#msg-10649 redskinsjbs Plastic Extruder Working Group Fri, 28 Mar 2008 14:24:52 -0400 https://reprap.org/forum/read.php?70,10542,10648#msg-10648 https://reprap.org/forum/read.php?70,10542,10648#msg-10648
I'm pretty much against mounting a granule extruder on a reprap because it would weigh too much and require too much beef in the positioning system to move it around at reasonable speeds.

Sorry to disappoint.]]> Forrest Higgs Plastic Extruder Working Group Fri, 28 Mar 2008 14:18:05 -0400 https://reprap.org/forum/read.php?70,10542,10647#msg-10647 https://reprap.org/forum/read.php?70,10542,10647#msg-10647
I read your blog and I swear you are a genius. Those pellets are so mush easier to find than the filament. One thing I would like to mention is that I think if you reduce the extrusion barrel length from 8mm downwards, the diameter of the filament will be less predictable. This isn't from and experience, it just seems like the longer the plastic is in the barrel, the more it will want to stay in that shape. Maybe you could do some tests when you get this thing up and running. If it works, I'll guarantee you that i will be the first to build a second one.]]> redskinsjbs Plastic Extruder Working Group Fri, 28 Mar 2008 14:11:40 -0400 https://reprap.org/forum/read.php?70,10542,10646#msg-10646 https://reprap.org/forum/read.php?70,10542,10646#msg-10646
[3dreplicators.com]]]> Forrest Higgs Plastic Extruder Working Group Fri, 28 Mar 2008 13:33:18 -0400 https://reprap.org/forum/read.php?70,10542,10637#msg-10637 https://reprap.org/forum/read.php?70,10542,10637#msg-10637 nophead Plastic Extruder Working Group Fri, 28 Mar 2008 04:52:13 -0400 https://reprap.org/forum/read.php?70,10542,10634#msg-10634 https://reprap.org/forum/read.php?70,10542,10634#msg-10634 Ian Adkins Plastic Extruder Working Group Fri, 28 Mar 2008 03:33:16 -0400 https://reprap.org/forum/read.php?70,10542,10630#msg-10630 https://reprap.org/forum/read.php?70,10542,10630#msg-10630 redskinsjbs Plastic Extruder Working Group Thu, 27 Mar 2008 21:08:01 -0400 https://reprap.org/forum/read.php?70,10542,10627#msg-10627 https://reprap.org/forum/read.php?70,10542,10627#msg-10627 Adrian Bowyer Plastic Extruder Working Group Thu, 27 Mar 2008 19:22:14 -0400 https://reprap.org/forum/read.php?70,10542,10625#msg-10625 https://reprap.org/forum/read.php?70,10542,10625#msg-10625 redskinsjbs Plastic Extruder Working Group Thu, 27 Mar 2008 19:10:54 -0400 https://reprap.org/forum/read.php?70,10542,10623#msg-10623 https://reprap.org/forum/read.php?70,10542,10623#msg-10623 Ian Adkins Plastic Extruder Working Group Thu, 27 Mar 2008 18:57:04 -0400