Ancient Sunlu PLA+ yellow (WHL #90)
After all that Geeetech bashing, here’s something for you, Sunlu fanbois! Sunlu PLA+ yellow!
Dammit, spoiled the results already…
Okay, here’s the deal: That stuff was given to me by a colleague who told me this is the worst printer filament he has ever laid eyes on. It’s stringing a gram of material for every gram of material printed. And I said: OK… (challenge accepted!)
The very same guy also gave me one of those half-kg spools of TPU quite a while ago and said it’s difficult to print and doesn’t look all that nice. This was easily fixed by just taking out all the moisture from the filament, since he kept it in the original bag that was cut open. Humidity goes in, bad prints come out. TPU might be a bit more hygroscopic or susceptible to lower levels of moisture than PLA or PETG, but his TPU is absolutely fine when dry.
The green PLA+ however..not so much. It does print fine on simple geometric shapes:
That all looks fine and dandy, until the print actually requires some movements with no extrusion (it’s a Raspberry case from somewhere off the interwebs, just as a test). Here’s some gyroid infill and one line of movement already pops out:
And then this happened.
And this.
Good Lord, what a POS…
This was the filament as I got it. I dried it, it got better, but it didn’t really lose all that much weight. Temp towers and retraction towers after a week:
So I checked the other options, since I do believe that Sunlu offers proper, usable filament:
* Could it be fake? I’ve never seen the green box before on any of my Sunlu purchases.
* Could it be old, as in degraded? It’s some PLA in steroids, after all, and PLA is biodegradeable.
“sunlu fake” yields a couple pages on the Googles and one guy on reddit had the same question with terrible PLA (non-plus I think) filament that he got for cheap. When digging deeper on the other question, it turned out that this (likely?) isn’t fake, this box has been used by Sunlu a long time ago. Which also answers the other question: Yup, it’s old. The Sunlu rep said “this item make from Fartory over 20 month” (yes, fartory), so with that conversation taking place on December 1st, that’s at least April 2021. He or she didn’t want to answer how to read the batch number from the supplied photo of box and reel, so I had a quick look at my embarrassingly large collection of new, active or fully used spools of Sunlu filament:
0119104011Z, 01105011: TPU black
0130012172Z, 15102051: PLA+ yellow
0812305261Z, 103002A: PETG white
0812305261Z, 103002A: PETG white (and another duplicate!)
0812305261Z, 103002A: PETG white (duplicate!)
0921306121A, 18101010A: PLA grey
0924305212Z, 03102001A: PLA+ black
1109305241Z, 03122001A: PLA+ silk black
1115305242Z, 03122063A: PLA+ silk red copper
1316304131A, 0110502B: TPU white
1725304231A, 10302A: PETG white
1741304192A, 13102A: PLA white matte
1838304202A, 13101A: PLA black matte
1928307222A, 10123067A: PLA marble
The second list entry is from the yellow PLA+, but I cannot really see any obvious datecode. Sure, it does have a “21” in it, but in other spools, that ranges from 40 to 72. The “20” in the other code also probably doesn’t stand for 2020, since that code varies in length and I think is more of a product code than a real serial number. Speaking of “serial”: It’s clearly not a unique number when three kg of PETG white have the exact same label on them. Yes, it should be the absolute same stuff, not a different tint and composition like recently seen on the Geeetech PETG, but tracing the individual roll isn’t possible with that information, they can probably only narrow it down to a day or a shift.
The first entry, the black TPU, could also be a tad older. All the other rolls however were purchased in the second half of 2023 via AliExpress frome one of the official Sunlu shops, so I would assume they’re not old stock.
Can someone shed some light on their batch numbers? I’ve marked a position in bold font that could be a month of production, as it only ever varies from 04 to 12, but that’s pure speculation and I’m still missing the more important information on the production year. Good old conditional formatting yields this:
Well, maybe the fifth column is the last digit of the year, so 2023 for most of them and 2021/2020 for the older rolls? But that doesn’t fully match up with the “over 20 month” statement – it would be 36 months at that point (yes, 36 is indeed over 20, but why understate the age of a problematic roll date when a customer is already asking about bad/fake/aged filament?)
Let’s purchase some new rolls in early 2024 and hope a “401” appears somewhere…!
As for that filament: It’s fully dry and it still strings like mad for anything with delicate contours. So I’ll just use it for simple shapes, like a block that protects my Y endstop on the printer when it’s tilted on the back and the entire gantry sits on top of that microswitch, or this lovely cylinder that’s just a mechanical adapter for winding up wire onto the slightly wider Geeetech spools – the original cordless drill adapter was measured from Sunlu ones 
The cylinder itself, printed in vase mode, is perfect – but look at the stringy mess it made from the purge line on the left, and after completion from the last position on the cylinder to the resting spot at X0/Y0…
Any other vendors with terrible filament that wanna get featured? 
