Introduction

xCE Black is a tough-rigid photo-polymer that can be used to print end-use plastic parts and injection molding tools in relatively quick time. It has high flexural strength and exhibits long term environmental stability making it ideal for printing long lasting parts for applications in automotive industry and electronics.  

Storage Requirements

Optimal storage temperature for xCE Black is between 8°C - 21°C. If the conditions are outside of these margins, it could result in loss of material properties. In general, store in original container away from direct sunlight in a cool, dry, and well-ventilated area. Prior to use, shake the container vigorously as contents may have separated.

Printing Tips

The default print settings for xCE Black are reliable for medium sized constant wall thickness parts printed between 30-60° from horizontal.

Due to the low viscosity and the high green strength, xCE Black is a good candidate for printing intricate designs with fine features and thin wall sections. Recommended minimum wall thickness for xCE Black is 0.5mm, but with vertical orientation and no sudden change in cross-sectional area, you can achieve a wall thickness as low as 0.3mm. Do keep in mind that all important features of the part(s) should be facing the membrane during printing for best possible surface finish.

xCE Black has a heat deflection temperature of 87°C (@0.45MPa) and therefore is a good candidate for tooling applications. Molding parts should ideally be designed/oriented in a self-supporting manner and be printed with the molding surfaces facing the membrane for smooth surface finish and high dimensional accuracy. Minimize shrink induced surface defects and resin cost by targeting constant-thickness mold designs using ~10mm thick walls and ribs. Or consider hollowing with lattice fill if redesign is not an option.

Example bottle mold – Part oriented at ~40-45° to be self supported around the molding surface + to avoid cupping related surface defects. Cone supports were used around the edges to ensure solid build plate adhesion.

Support separation is observed from time to time on medium to large size parts printed with xCE Black. This is a result of peel forces acting on the rigid support structures causing the support tips to break off from the parts’ surface. In addition to making the supports strength “strong”, users can increase the Contact penetration (+0.1mm), decrease the Unit cell size (-1.0mm), and increase the Minimum distance to part (+1.0mm) to minimize support separation. Use of cones around the edges of the part is recommended for any large part (+100 ml of resin) to ensure build platform adhesion and higher print success.

Default support settings for xCE Black. Users can increase Contact penetration (+0.1mm), decrease Unit cell size (-1mm), and increase Minimum distance to part (+1mm) to minimize support separation.

Post Process Tips

Validated Workflows (based on 4mm tensile coupons)

If parts are printed directly on the build platform, the slots on the platform will be imprinted on the down-facing skin and will require sanding to remove the stripe-like pattern. In general, xCE Black supports can be easily removed and supported areas can be sanded off to get a nice clean surface finish. If you are dealing with thin wall parts, it is recommended to post-cure the parts with supports still attached so that the amount of deforming/warping can be controlled. When there is a large supported area, the most complete washing and curing can be achieved with supports removed.

Washing

• xCE Black parts should be put through 2 xClean baths (dirty and clean) for 10-2 mins each. Parts can then be rinsed off in water or IPA as the final bath.
• Make sure the parts are completely dry before post-curing them in the xCure unit.

Curing

• 60min with UV only in the xCURE is recommended.
• Post cure parts with supports still attached so that they will hold their shapes + minimize deformation during post-curing (parts <2mm wall thickness).
• Heated curing and extended cure time may help improve cure depth on thick parts (>4mm wall thickness).

Updated January 06, 2023 18:17