BPE

Step 1

Printing

The chamber and the print bed are heated and brought to temperature before the start of the printing process. The bound metal powder filament is brittle at room temperature so also needs to be warmed in the chamber before loading. The material filament is then extruded and melted as it passes through the print head and forms the object layer by layer. Both the object and any required supports are produced in the same bound metal powder filament until the print is complete.

Step 2

Debinding (Washing out additives from previous processes)

Parts are then placed in a proprietary circulating bath containing an environmentally sustainable solvent with a high evaporation rate. This breaks down the polymer binder material throughout the entire part. Parts are then transferred to an air drying bin to clear all of the solvent. At the end of the drying process the part is in "green-part" form which is still held together by the residual polymer binder.

Step 3

Sintering

Green parts are then transferred to a furnace for around 24 hours where the sintering transforms it from a lightly bound metal powder into a full metal part. The early stage of this process burns out the remaining polymer, then the metal part shrinks to its final design size. Once sintering is complete the furnace switches off and the parts cool inside until safe to remove. The sinter shrinkage rate needs to be compensated for in the original CAD design.

Step 4

Support Removal

Manual Removal Supports are often breakaway types and can be manually removed before or after sintering. Soluble Support Removal Some systems use soluble supports (e.g., in the green state) that dissolve in a chemical bath. Manual Cleaning Note: Supports are easiest to remove in the green state (pre-debinding) to avoid damaging the fragile or fully sintered part.

Step 5

Surface Finishing

Sanding / Polishing Applicable after sintering to improve surface finish and remove small imperfections; parts are often rougher than laser-based metal AM. Chemical Smoothing / Coating Electropolishing or chemical etching is possible for some metals post-sintering. Painting / Priming Rare, but can be done for cosmetic or corrosion resistance. Gloss / Matte Control Controlled via polishing or coatings; parts are typically matte or slightly textured as-sintered.

Step 6

Curing / Heat Treatment

UV / Thermal Curing Non-applicable Annealing / Stress Relief Sintering is the key process: Debinding removes polymer matrix. High-temperature sintering densifies the part, typically in a controlled atmosphere furnace. Additional heat treatments (e.g., quenching, tempering) may be applied based on material and application

Step 7

Assembly and Functional Finishing

Gluing or Bonding Can be used for hybrid assemblies, but welding is often more appropriate. Drilling / Tapping / CNC Very common; secondary machining improves tolerance, surface finish, or adds functional features. Inserts / Fasteners Threaded inserts and fasteners can be added after sintering, or threads may be machined directly.

Step 8

Special Treatments

Infiltration / Sealing Non-applicable in most cases; sintering results in high-density metal, though not always 100% dense. Functional Coatings Can include anodizing (aluminum), passivation (stainless steel), or wear-resistant coatings. Post-print Functionalisation May include heat treatment, HIP (hot isostatic pressing), or machining to meet end-use specifications.