CJP

Step 1

Printing

The gypsum powder material is spread in a thin layer across the build platform by the re-coater. Then colour binding agent is selectively jetted from inkjet print heads following the contours of the slice file, causing the core to bond the part's cross section. The build platform then lowers by the preset layer height to allow every subsequent layer to be spread and printed with each layer bonding to the previous one beneath it, resulting in a full-colour three-dimensional model.

Step 2

Support Removal

Manual Removal No solid supports; unbound powder acts as self-supporting medium. Soluble Support Removal Non-applicable Manual Cleaning Note: Excess powder is removed using a brush, air blower, or vacuum; parts are fragile and must be handled with care during cleaning.

Step 3

Surface Finishing

Sanding / Polishing Not typically done; parts are too brittle for mechanical abrasion. Chemical Smoothing / Coating Infiltrants like cyanoacrylate (superglue) or epoxy are applied to strengthen and protect surfaces. Painting / Priming Rarely needed due to full-color capability, but possible for repair or added effects. Gloss / Matte Control Controlled by the type of infiltrant used (e.g., glossy epoxy vs. matte CA glue.)

Step 4

Curing / Heat Treatment

UV / Thermal Curing Non-applicable. Annealing / Stress Relief Non-applicable.

Step 5

Assembly and Functional Finishing

Gluing or Bonding Common when assembling multipart models; CA glue or epoxy recommended. Drilling / Tapping / CNC Not advised; material is too brittle. Inserts / Fasteners Non-applicable; parts are not intended for mechanical assembly.

Step 6

Special Treatments

Infiltration / Sealing Essential. Infiltration with CA glue, epoxy, or wax provides strength and protects colour intensity. Functional Coatings Optional clear coat (glossy or matte) can add protection or enhance appearance. Post-print Functionalisation Some users add felt bases, nameplates, or mounting hardware for presentation purposes.

Step 7

Design Notes

Due to the unbound Gypsum material being 100% re-usable, CJP is most cost-effective when parts are designed hollow. For objects that need to have a continuous outside surface, a powder escape hole can be designed with a corresponding plug that can be inserted post-printing and hardening. Objects produced in CJP are intrinsically fragile and hollowing only makes them more so. It can be beneficial to fill internal voids by pouring resins into cavities before sealing with the printed plug. This makes hollowed objects more robust but will add weight. Be aware that the colour binder is only applied to the outside surface of the object, therefore any abrasion of the surface will quickly remove the colour and reveal the clear bound gypsum beneath.