tough PLA: too strong buildplate adhesion

[aag 6]

I am printing Tough PLA models with a VERY large base, sometimes occupying the entire buildplate. And they adhere extremely strongly to the plate. Adhesion is a good thing, but this is clearly too much. What is the best practice for getting a Tough PLA model off the plate without resorting to ice picks etc.?

 

[Dim3nsioneer 557]

Simply use a thin layer of glue stick. It gives you a very well defined adhesion.

[Smithy 1,144]

 

[aag 6]

OK thanks, I will move back to the UHU sticks which I had abandoned earlier. Has anybody tried to make "diluted UHU"? I was thinking of something like a 1:1 UHU in water, which could be easier and faster to homogeneously apply to the glass, perhaps with a large brush...

[Smithy 1,144]

No, but if you don't use too much water it could work. It is the same if you dissolve PVA in water and use this for adhesion, which works also very well.

 

For ToughPLA I used glue stick only and do not distribute it with a wet tissue. If the glue layer is thicker the part comes off better. 

 

I think the problem with too much adhesion of TPLA depends hardly on the size and shape of the model. My model was not so big but had a big support structure at the bottom and it was always hard to get these models off. But I got the best result with glue only.

 

And ofc, let the glass cool down really long and if you have the possibility to put it in a freezer or if you have a "cold/freeze spray" (hope this is the correct English name) then if helps also that the part pops off.

[aag 6]

Might a printed single-layer PVA raft be equally effective in getting easier release from the plate?

[Smithy 1,144]

Yes, that could help a lot, I haven't tried it. And in the worst case, you could just put some water around your part and wait until it dissolves.

[Dim3nsioneer 557]

You wait forever until a single layer of PVA dissolves below a flat surface. I tried it once with a small area and waited more than a day although the water in the box was in motion. If you do it, put the glass in the freezer first, take the print away and then dissolve it. Having said this, you can also put the glass into the freezer with the Tough PLA printed directly on it. 😉

[aag 6]

Thanks but too late; I did that already... 😱. It also added some 2 hours to the printing process. Probably not a great idea...

[Smithy 1,144]

But maybe you get it off easier due the PVA raft - before dissolving, so it is still worth the try.

[Framar 38]

I have good result spraying 3Dlac on the glass. The prints detached easily once cooled.

[geert_2 557]

Maybe you could try the "salt method" on a small test piece?

 

Or even better, on the same buildplate, print this test model multiple times using different methods. With a marker, draw lines on the glass, and use a different method in each area:

- none at all

- salt method

- glue stick

- dilluted wood glue

- PVA-layer

- 3D-LAC (spray on tissue and wipe with that, so you don't cover the whole glass)

- hairspray

- other...?

 

The "salt method" works by first cleaning the glass thoroughly, then clean again with warm tap water only. And then wipe with a tissue moistened with *salt water*. Gently, always gently, keep wiping while it dries into an almost invisible mist of salt. It should look like a clean wine-glass that hasn't been used for a year: it is still clean, but you see a very faint haze on it.

 

For next prints, you can just re-wipe the glass with the tissue with salt water. No need to take the glass out of the printer and clean it again. I haven't taken out and cleaned mine in a year.

 

For regular PLA, this gives a very good bonding when hot, but absolutely no bonding when cold. However, it is not optimal for narrow, vertical models like lantern poles: the salt can not absorb shocks and then it tends to come lose. But for long, low, flat and 100% filled models like mine it works very well: I have printed many hundreds of my typical models now without problems.

 

But I don't know if works for tough PLA? So make sure you stay with the printer. And please let us know, I would welcome feedback.

 

Photo of my typical models (regular PLA, 100% filled): the front one is freshly printed. The back one has been sitting in a laboratory oven at ca. 70°C for a couple of hours, to try the effect: this gives an idea of the build-in material stresses that a bonding needs to withstand while printing.

 

[kfsone 5]

My solution was just to reduce the first layer height and width. TPLAs inherent adhesion is good enough without needing to crush it against the plate. Also results in a more consistent glossy finish.

 

No curling, no elephants foot. The line width may not even need reducing but I found it made the gloss a little less shiny-polished, and for the piece I'm printing that was a better look.

 

The other thing you might consider: if you have one of the newer build plates, the side of the plate with the heat sticker on it has better adhesion. Flipping the build plate with give you slightly less adhesion, but again, TPLA is already good.

 

 

[aag 6]

Thank you, very useful! In the meantime I have bought a whole box of Uhu sticks, the large ones (40g each). It takes <10 seconds to spread a layer of Uhu all over the plate. The results are satisfactory thus far.

I tried the PVA raft method, and it is excruciatingly slow. It adds 1 hr to the printing and several hrs to the releasing with water. I do not recommend it. 

[arverbo 0]

@kfsone thanks for the tip. The print comes loose more easely with these settings.