Printing in engineering-grade polymers does require a bit of extra care - to ensure the strongest part possible, we recommend the following procedures.
PEEK and PEI are moisture-sensitive materials. It is vital to keep the filaments away from moisture before and during printing. PEI is more sensitive to moisture than PEEK.
Prior to printing, it is necessary to keep residual moisture of filaments to below 0.02% to prevent foamy extrudate due to high vapor pressure caused by trace of moisture at high printing temperature. An air circulating oven can be used to dry filaments before printing. Drying temperature and time for PEEK is 150℃/3 hours or 120℃/5 hours. Meanwhile, drying temperature and time for PEI is 150℃/4 to 6 hours. PEI Is more sensitive to moisture. Please ensure several bags of desiccant are placed inside the filament chamber when printing. Store PEEK and PEI filaments in sealed bag with desiccant after printing. If the filament is sufficiently dry, the extrudate should be transparent and without bubbles.
For PEEK and PEI printing, use the frosted side of the glass plate. Special PVP glue stick is desired for glass plate gluing. Correctly applying the glue is important to ensure good adhesion of your print to the glass plate. The following steps are recommended for gluing:
Cleaning. Clean the glass surface with water, and wipe to dry；
Gluing, grinding and heating. Evenly apply 2 to 4 layers of glue on the glass plate. It’s only necessary to apply glue to the print area. Place the glass plate on build plate for heating at 100℃ for 3 to 5 minutes. Then, remove the glass from chamber for cool down to room temperature. Grind the glass surface with a blade to evenly flatten the glue surface;
Repeat the above steps one or two times;
The treated glass plate is now ready for printing.
After printing, remove the print and clean the glass plate with water.
For optimal results, it is recommended that you always preheat the build plate and chamber temperatures to 160℃ and 90℃ (temp for printing) respectively for at least 30 minutes before bed leveling or printing.
Once your 3D print is completed, it must be removed from the build plate while it's temperature is still high. Removing a print after it has cooled may cause the glass plate to break because the print may shrink more rapidly than the glass plate.