Moldjet

Step 1

Printing

The Moldjet process involves the parts passing through six stages or machine stations to produce the final near net shape parts in either metal or ceramic. Station one is where the mould is formed, the wax-like mould material being precisely jetted via piezoelectric print heads onto the build plate in the form of the cross section of the negative build space at the first layer. Station two is where the selected metal or ceramic paste material is forced into all of the cavities of the first build layer. Once this is complete, a blade moves across the top surface to wipe away any excess material. Station three is where the metal or ceramic paste material is rapidly dried and hardened by hot air within a vacuum. Station four is where an optical inspection takes place using AI real time image analysis which if followed by any autocorrection or layer removal if required. Station five is where a high-resolution camera conducts real-time AI-driven inspection of each layer. If any defect is found, that layer is milled away and re-processed. At this point the build returns to stations one through to four until each of the entire build layers has been completed. At the end of which one is left with a completed build tray (surrounding mould form with dried material parts embedded within.) Station six is where once the build is complete, the parts are removed from the machine. The wax-like mold material is then chemically dissolved (demolded) in a solvent bath, leaving behind solid green parts. These parts are then typically sintered to achieve their final density and strength.

Step 2

Support Removal

Manual Removal: Non-applicable; MoldJet eliminates the need for support structures during printing. Soluble Support Removal: Non-applicable. Manual Cleaning Note: The wax mould is removed automatically before sintering, leaving a freestanding green part; light cleaning may be done before sintering to ensure surface quality.

Step 3

Surface Finishing

Sanding / Polishing: Common after sintering, especially for functional or aesthetic applications. Chemical Smoothing / Coating: Electropolishing, passivation, or acid etching may be used depending on alloy and part requirements. Painting / Priming: Applied if required for aesthetics or corrosion protection. Gloss / Matte Control: Naturally good surface finish (better than binder jetting); final finish determined by coatings or polishing.

Step 4

Curing / Heat Treatment

UV / Thermal Curing: Non-applicable during printing. Annealing / Stress Relief: Standard practice: Debinding: Polymer binder is removed from the green part. Sintering: Metal powder is fused into a dense part in a high-temperature furnace. Additional heat treatments (e.g., tempering, hardening) may follow depending on material.

Step 5

Assembly and Functional Finishing

Gluing or Bonding: Occasionally used for hybrid assemblies or aesthetic parts. Drilling / Tapping / CNC: Common post-sintering, especially to improve tolerances or add mechanical features. Inserts / Fasteners: Threaded inserts or machined threads are frequently added to support functional assembly.

Step 6

Special Treatments

Infiltration / Sealing: Optional, if further densification or sealing is needed; however, sintered parts are typically dense enough without infiltration. Functional Coatings: May include nickel plating, anodising, or anti-corrosion coatings, depending on the metal. Post-print Functionalisation: Parts can be machined, joined, coated, or assembled with other components just like traditionally manufactured metal parts.