I just finished recoating 3 tanks and was looking to buy some more Sylgard, and got some serious sticker shock.
Sylgard 184 price have more than doubled in the past year. Back in December 2017, I bought a 0.5Kg kit from Krayden, for $45 + shipping. Today, that same kit is $145. Granted that the $45 price I paid was because it was on sale from about $60. But todays price left me speechless.
So I started looking around for better pricing. Ellsworth seems to be the cheapest around for Sylgard. Even the other brands have gone way up. I remember ML solar selling for about $25 for a 1/2 Kg, it’s now up to about $55-60, and QSil 216 is about $50-60.
Has anyone else notice this price increase? What could be the reason?
Just looking at getting into re coating my resin trays. Big issue is what is used to clean them totally before applying the silicone PDMS layer?
Probably the reason is that everyone involved in 3DP started to re-coat their tanks. The demand exploses so do the prices. Market laws.
I doubt that’s it.
Sylgard and other silicone encapsulants like it are used in the Solar cell industry to encapsulate the solar cell and make it waterproof, while maintaining the clarity. The use for PDMS recoating accounts for a very small percentage of the total consumption.
There might be better articles describing the global silicone chemical supply crunch in 2018, but this one was easy to find: https://www.gep.com/mind/blog/silicone-prices-surge-globally-as-supply-dwindles-what-does-the-future-hold
For the Form 1, there is no way to totally clean the tank, namely the sides, becuase it’s made from acrylic and alcohol would deteriorate and crack the acrylic.
I put the tray in a sink that has water and Dawn dishwashing liquid, and that does the job on resin that is still liquid, the stuff that’s caked on the sides a dry, there’s not removing that.
But the important thing is the clear window, and the trick is to NOT remove the old PDMS, until you cleaned and dried the rest of the tank. When you remove the old PDMS, the window underneath is already clean and dry and doesn’t need to be touched. Just pour your Sylgard mix.
Thank you for this. I had no idea.
Sounds good but the resin has gone under the PDMS layer so it has to be removed in order to clean the resin tray totally. Otherwise I’d be pouring a new PDMS layer on to a dirty window. I’ll try water and Magic 7 as that should do it.
Try FEP film instead of silicone.
You can buy rolls and sheets of it, with adhesive.
It’s a nightmare to apply, but should last you a fair bit longer than PDMS, as long as you apply it in a way the resin can’t seep under it and eat away the adhesive.
That’s what i used way way back in form1 era, on a homebrewed SLA printer.
Now that PDMS prices are up, might be a more cost effective alternative?
Do the LT trays use FEP films?
Hasn’t been confirmed by Formlabs but yeah, probably. Looks like it anyway.
What is a commercial name or brand for FEP material?
Also, on the resin seep under the FEP layer. Why not run a bead of Silicone glue around the edges to seal them?
This is what I’m doing with any new trays from Formlabs as de lamination of the PDMS layer has ruined a number of my resin trays. The Silicone Glue helps stop that.
Yeah, LT tanks look like FEP, although that was never officially confirmed.
Commercial name for FEP is Teflon film.
Nice trick with the silicone glue, got to try that, as i had a bunch of tanks go bad like that too recently.
As a sidenote, i also had a bunch of platforms pop out the corks on the sides (i assume from IPA seeping in, and the temperature differential when the platform gets dunked into warm resin) and ended up sealing them with silicone beads.
I’ve been using both a Form 1+ and now 2 Form 2 units with multiple build plates and have never had one with any of the issues mentioned by others. Only problem I’ve had in the past were gouges in the build plate from the resin welding to the surface. That’s past and the ALW’s resin pops of nice and clean.
On the FEP, where do you find the adhesive kind and what thickness should be used.
Yes, the silicone glue (GE brand) works great and I feel that will solve a lot of the problems with the new resin trays from Formlabs de-laminating.
I’ll chime in on some of these subjects:
Build platform. I bought an extra one at the time I got my first printer. Never had to use it . The original still works just like it did in the beginning. I don’t really clean mine in the true sense. Once I pop the model off, I simply use a paper towel to clean it, and put it back in the printer. I don’t use cleaners, IPA, or anything like it.
Damaged PDMS & Silicone glue. I don’t see how IPA can find it’s way under the PDMS, since you’re not supposed to use IPA to clean the tank. Gluing the edges back to the sides of the tray, might sound like a good idea, provided you throw away the tray and don’t plan to recoat it. Because you’ll never be able to get the original PDMS and the glue off.
FEP film. I purchased one of those CNC Aluminum trays with replaceable FEP, and I just couldn’t make it work at all. The resin just sticks to the film and doesn’t release. I even bought a new roll of FEP film from FlexVat, which is designed for this specific job. No luck what soever. I tried lowering and raising the platform from fully touching the film to nearly 1mm spacing. Needless to say, the tray in now sitting in a closet. Maybe some day I’ll figure out how to put a glass piece in there.
Since I’m still using my Form 1+, and FormLabs has graciously seen to it that trays are no longer available, I have to recoat. However, in the mean time I found that the Peopoly Moai printer tray is identical to the Form 1+ tray, so I bought a couple (they’re only $35.00 each). I’m now waiting for them to be shipped from Asia.
I’ve Had a close look at the base of the LT tanks and the FEP layer ( if it is FEP) is about 1 mm thick, but is tightly bonded to the acrylic base of the tank. So the chances of relining these tanks seems to be slim.
It’s a thin sheet backed by 1mm foam which is attached to the tray itself. You can make this yourself but need the right tooling as FEP has a difficulty sticking to anything, even with the right glue.
Following is a reply to my question on FEP to Kevin Chen of ALW resin suppiers.
FEP vs. PDMS
FEP film, that is what LT resin tray is (FEP film on top of PDMS). FEP is DuPont Teflon film, FEP is more chemical & heat resistant than PDMS. However, when it comes to “release” PDMS is better than FEP, meaning it takes less peel force to detach the printed layer form PDMS than FEP. With better “release”, PDMS gives the Form2 an edge on fine print detail over FEP film printers. Because FEP requires greater peel force to release, the fine details get deformed or detached, possibly resulting in fail prints.
From2 Resin Tray
After the printer is properly leveled, most of the time when you swap out resin trays for color change or resin type, Z axis calibration is not required. This is because:
- Trays have standard bottom thickness: PDMS + clear acrylic window
- Form 2 is equiped with pressure sensor to compensate for the thickness fault tolorance
- FL recommend to print with base-raft & supports (some time you will notice the base-raft is thicker from one printer than other)
However, when the tray bottome thickness is out of the set tolorance range, manual recalibration of Z hight is required.
FEP film in From2 Tray
One can not directly glue the FEP film on to the acrylic window without PDMS film because of the hight difference would be out of tolorance range that the Form2 is desinged for. Putting the FEP film on PDMS is “tricky” because both materials are designed for none-stick surface. Achieving a solid bonding of FEP and PDMS is timing, when the PDMS is not in liquid form and mixed solution is clear of tiny air bubbles, lay down the FEP quickly without any bubbles traping in between and without deforming the PDMS (is it still soft to touch) then cure the PDMS fully. Due to this difficult process, FL had a long delay on the LT Resin Tray moreover many defective LT Resin Trays did performing as FL had hoped for. During printing, when laser hits the resin, the chemical reaction would quickly heat up to hundres of degrees to solidify. Any tiny air bubbles traped in PDMS or in-between would quickly expand and causes delimination. Not all deliminations are caused by chemical reactions, rather it is a physical air bubble expansion pushing agaist the PDMS.
FEP self-adhesive sheets
From our experience, the self-adhesive sheet would face the challenges of:
- High temperature during print
- PDMS’s non-stick nature
- Possibility of trapped air bubbles
FEP film use in other printers
Most of the FEP film printers do not glue the film to any backing. The Film is tentions around all edges, like a trampolien/drum so it is flexible. This even tention and flexibility is important to enable the pressure sensor to auto calibrate the Z hight evenly.
“FEP” Film is made by Teflon, as well as several other manufacturers
(For example: https://www.films.saint-gobain.com/products/chemfilm/fep-films/fep-fg or https://www.polyflon.co.uk/products/fluoropolymer-film/fep-film/)
Fluorinated Ethylene Propylene is the full name for the material. Its correct that it has slightly greater print adhesion than PDMS, however its UV transmission over a period of printing time is significantly better than PDMS. It does not suffer the same degree of “clouding” as PDMS after exposure to UV. PDMS deteriorates quickly after exposure to UV and reduces the accuracy of a part by the diffusion caused by the clouding. FEP on the other hand is normally good for several hundred prints with no visible damage from the UV.
The biggest challenge is keeping it under tension AND supported during the print. Which is not easy with the current FORM 2 tank design. Dont forget that if using an adhesive with FEP film that has two issues - adherence and UV transmission, the two do not go hand in hand