A freshly printed part is a starting point, not a finished product. Post-processing transforms layer lines into smooth surfaces, removes support witness marks, improves mechanical properties, and in some cases fundamentally changes what the part can do. Layer X runs every major post-processing workflow in-house, and this guide explains what each one achieves.
Mechanical Finishing: Sanding and Bead Blasting
Hand sanding (80–2000 grit progression) is the baseline for FDM surface improvement. It is time-consuming but achieves any surface finish the customer needs. For SLS nylon, glass-bead blasting uniformly compresses the granular surface and removes loose powder, leaving a consistent matte finish suitable for direct paint adhesion without priming. DMLS metal parts are bead-blasted as standard to remove partially fused powder and achieve Ra ≤3.2 µm.
Vapour Smoothing (ABS and ASA)
Acetone vapour dissolves the outer 20–50 µm of ABS and ASA surfaces, flow-filling layer valleys and producing near-injection-moulded surface quality (Ra ≤0.8 µm) in 20 minutes. The process also improves inter-layer bonding by reflowing the surface polymer, increasing impact strength by 10–25%. Layer X uses a closed-loop vapour chamber with condensation recovery — safe and consistent.
The trade-off: vapour smoothing slightly rounds sharp edges and reduces dimensional accuracy by 0.05–0.15 mm. Annotate any critical dimensions that must hold post-smoothing.
Epoxy Sealing
XTC-3D and similar epoxy coatings seal FDM and SLS surfaces against moisture, fuels, and gases. The two-part coat adds 0.3–0.5 mm per side, significantly improves surface hardness, and provides a neutral base for paint. It is mandatory for any fluid-handling FDM part and strongly recommended for outdoor applications.
Annealing (PETG, Nylon, ASA)
Controlled heat treatment at 80–120 °C for 1–4 hours relieves internal stresses introduced during FDM extrusion. Annealed PETG parts show 15–20% improvement in impact resistance and reduced creep under sustained load. Annealed nylon densifies slightly — account for 0.3–0.5% linear shrinkage when designing annealed parts.
Surface Dyeing (SLS Nylon)
SLS nylon accepts reactive dyes at boiling temperatures. The dye penetrates 0.3–0.5 mm into the surface, producing colour that will not chip or peel. RAL colour matching is achievable to within ΔE ≤3. This is the standard finish for consumer product components and medical device housings where colour coding is required.
Metal Plating (FDM and SLA)
Copper, nickel, or chrome electroplating of 3D printed plastic parts — via electroless copper seeding followed by electrolytic build-up — produces conductive, metallic-looking parts at a fraction of machined metal cost. Popular for RF shielding enclosures, architectural hardware mock-ups, and consumer electronics models.
HIP (Hot Isostatic Pressing) for DMLS Metal
Hot Isostatic Pressing applies heat and isostatic pressure simultaneously to close residual porosity in DMLS parts, improving fatigue life by up to 40% and elongation at break by 30%. Layer X partners with a certified HIP facility in Pune. Required for fracture-critical aerospace structures and any DMLS part subject to fatigue loading. Add 10–14 days to lead time.
Requesting Post-Processing
All post-processing is selectable in the Layer X quote form. Describe the finish required (surface roughness Ra, colour, coating) and the critical dimensions that must be held post-process. Our engineers will recommend the workflow and add the cost to your quote within 24 hours.