PEI build surface
PEI (Polyetherimide), also known as Ultem, is a reusable "relatively maintenance free" build surface for both ABS (with a Heated Bed) and PLA (hot or cold) requiring no additional adhesives such as glue or tape. PEI is appealing due to its "no-surface-prep" conditions, which make it convenient to work with. Additionally, printing on PEI requires no support rafts as parts adhere directly to the surface with no issue.
More Information can be found: http://kuehlingkuehling.de/2013/04/02/development-roundup-metal-hotends-new-print-surface-rjmp-linear-bearings-watercooling/
How do I use this?
Purchase a sheet of 0.03" - 0.04" thick PEI, thinner can be used but it is more difficult to apply exactly flat to your surface. PEI is easily cut to size by scoring with a hobby knife. Laminate your sheet of PEI using 3M 468MP Adhesive Transfer Tape to a glass/mirror print bed, keeping in mind that 3M 468MP is a very tacky tape that is prone to clumping. The type of glass you choose does not matter as long as you provide even heating of your glass (for example, if using a Mk2A/B heat bed, have your glass cut to 200 mm x 195 mm). The side of the PEI you choose (if your sides are different) does not matter, as it simply changes the appearance of the part underside.
Once you have laminated your sheet of PEI onto your glass, simply re-level your print bed and set your heated bed to 85 C for ABS and print away. Parts should come free from the surface with almost no issue at all. PLA does not require heat, but turning the heated bed up to 45C helps.
Before each print, wipe your PEI surface down with 70-91% Isopropyl alcohol, to ensure that you wipe away any grease or other residues that may have accumulated on the surface. This will help increase your surface adhesion greatly.
And Or Not:
8" x 8" PEI - https://www.amazon.com/dp/B074XK8BWY
10" x 10" PEI - https://www.amazon.com/dp/B074XLCSX7
12" x 12" PEI - https://www.amazon.com/dp/B074XG1NDM
16" x 16" PEI - https://www.amazon.com/dp/B074XKQNKT
http://www.amazon.com/dp/B0013HKZTA/ref=biss_dp_t_asn (0.03" or 0.76mm)
You can also find PEI labeled as Ultem from suppliers such as McMaster-Carr: the 0.040" variety is suitable for printing.
12" square of 468MP adhesive: http://www.digikey.com/product-detail/en/12X12-6-468MP/3M9720-ND/2649265
8" x 8" 3M 468MP Adhesive - https://www.amazon.com/Gizmo-Dorks-Adhesive-Transfer-Sheets/dp/B01HP2C9FE
10" x 10" 3M 468MP Adhesive - https://www.amazon.com/Gizmo-Dorks-Adhesive-Transfer-Sheets/dp/B01JPWSY6A
12" x 12" 3M 468MP Adhesive - https://www.amazon.com/Gizmo-Dorks-Adhesive-Transfer-Sheets/dp/B01HP2CEG8
Cleaning & Maintenance
Use isopropyl alcohol, methyl alcohol, soap, Heptane, Hexane, or Naphtha. Avoid ketones (such as MEK) or strong bases (such as sodium hydroxide).
In other words, PEI can be cleaned through the use of Isopropyl Alcohol, which will theoretically help adhesion should you lose it.
Note that as of the writing of this article (02/05/2015), proper tests have not been carried out to determine the best method of cleaning PEI, the recommendations above are sourced from a brochure for Ultem. Please add cleaning methods that have worked for you.
Known to work: Isopropyl Alcohol (91%) Soap and Water (initial wash after cutting)
I have now printed both ABS and PLA on PEI.
For ABS, I use a J-Head (original) temperature of 240 degrees C, and a heated bed temperature of 100 degrees C. For PLA, I use a J-Head (original) temperature of 195 degrees C, and a heated bed temperature of 60 degrees C.
The process I took to get my PEI to working state was as follows: I laminated a 0.030" thick sheet of PEI onto window glass sourced from Lowe's (to preserve flatness) with 3M 468MP Adhesive Transfer Tape.
Additionally, my PEI had two different sides (one matte and one glossy), it is unknown the difference these sides cause to prints - I have performed approximately 50 prints (as of writing this section 02/16/2015) on the matte side with no ill effects noticed.
Originally, I was advised to start my heated bed out at 80 degrees C, but I was experiencing lifting with longer parts. This led me to continually increase my bed temperatures until I settled on 100 degrees C being my final point. At 90 I was receiving lifting, at 110 parts were nearly impossible to remove, but at 100 the parts adhered as expected.
One thing to note is that before each print, I do a quick wipe down with 91% IPA (and a cotton ball) to eliminate any possible finger residue that could have gotten on the PEI. This seems to help promote adhesion, and as far, there are no visible ill effects to the surface.
I'm using 0.03" (~0.76mm) PEI taped to glass (borosilicate) with adhesive transfer tape. I've only tested with PLA so far. I'll be doing some ABS soon. I haven't needed to use a heated bed for PLA. 70% Isopropyl alcohol cleaning works for about two to three prints. I find keeping a cotton pad with the isopropyl alcohol on it next to the printer is convenient for cleaning after removing the last print.
I've now done a few prints with ABS. I've had no issues with prints lifting with the bed at 70C. I haven't needed a brim with it at 70C either.
JRDM's (jeffdm) Notes
I've managed to build ABS, a couple custom ABS blends with other plastics, PLA, Form Futura flex PLA, PETG and HIPS on PEI. I did the same as quillford above, on borosilicate and plain window glass.
Make sure the build plate is trammed well.
I tend to use 100˚C bed temp for ABS and 60˚C for PLA.
I've seen people recommend using a fine sandpaper to recover adhesion if the above wipes don't help. I haven't needed to do this yet, and I've made hundreds of parts on a single piece of PEI so far. I really like getting away from tapes, sprays, glues and ABS slurry. I don't need brims or contact discs to increase contact patch area. You do want to avoid scratching or the PEI, or else the scratches and damage will be visible on the parts.
I still find it helpful to have an enclosure, I currently use a cardboard box heated to 36-40˚C air environment. Turbulence from exhaust fans still can cause problems. I don't get delamination issues with good nozzle, bed and air temps.
I bought mine from Amazon and it came smooth on both sides. It wasn't that grippy, but after a light sand blast it was perfect. It held quite large ABS parts, and PLA didn't stick too much that it wasn't removable.
About a year later and some heavy use, the adhesion wasn't very good. I cleaned it with some rubbing alcohol and used 800 water-resistant sandpaper on it. (with water, lightly and mostly in the center where I printed the most) The adhesion returned to its original perfect condition.