Post-Processing Techniques for SLS Printed Parts

While SLS parts can often be used as-printed, post-processing unlocks additional possibilities for enhanced appearance, improved properties, and specialized functionality.

Depowdering Basics

Initial Removal

After build completion and cooling, carefully remove parts from the powder cake using appropriate tools. Work systematically to avoid damaging delicate features.

Compressed Air Cleaning

Use compressed air (30-60 PSI) to remove loose powder from surfaces and internal cavities. Work in a ventilated area or powder booth to contain airborne particles.

Bead Blasting

For thorough powder removal from complex geometries, use fine glass bead blasting (60-100 mesh) at low pressure. This also provides light surface texturing.

Surface Finishing

Tumbling

Vibratory tumbling with ceramic or plastic media smooths surfaces and removes loose particles. Process times vary from 2-24 hours based on desired finish.

Sanding

For critical surfaces, progressive wet sanding from 320 to 1200 grit achieves smooth finishes. Work systematically to maintain part dimensions.

Vapor Smoothing

Chemical vapor smoothing dissolves surface roughness, creating glass-like finishes on PA materials. Professional service bureaus offer this specialized process.

Dyeing & Coloring

Immersion Dyeing

PA12 and PA11 readily accept dye through hot water immersion (80-100°C). Acid dyes provide vibrant, permanent colors with excellent lightfastness.

Dye Process

Clean parts thoroughly, prepare dye bath to manufacturer specifications, immerse parts for 15-45 minutes, rinse thoroughly, and air dry completely.

Color Options

Standard dye colors include black, red, blue, green, yellow, and orange. Custom colors are possible through dye mixing.

Coatings & Sealing

Spray Primers

Automotive primers provide excellent base coats for painting. Multiple light coats build uniform coverage without obscuring details.

Paint Application

After priming, any standard paint system works. Two-part urethanes provide excellent durability for functional parts.

Secondary Operations

Tapping & Threading

SLS parts accept taps and thread-forming operations easily. Pre-drill holes slightly undersized for optimal thread engagement.

Heat Set Inserts

Brass heat-set inserts provide durable threaded connections. Use insertion tools at appropriate temperatures to avoid melting surrounding material.

Conclusion

Post-processing transforms SLS parts from functional prototypes to production-quality components. SinterX parts respond well to all standard finishing techniques.