Why Dyeing Beats Spray Painting
When prototypes require color, painting is often the default choice. However, paint adds 50-100 microns of thickness (ruining tight tolerances) and chips off under everyday scratching to reveal the raw white or grey plastic underneath.
Because Selective Laser Sintered (SLS) Nylon is naturally porous, it can be dyed directly. Specialized acid and disperse dyes penetrate 0.2 to 0.5 mm into the polymer matrix, resulting in a scratch-proof, vibrant finish with zero dimensional growth.
The Industrial Dyeing Recipe
- Pre-Cleaning: Thoroughly bead-blast the part to remove all residual unbound PA12 powder. Sonic-wash in warm water with mild detergent to remove oils and finger grease.
- Temperature Control: Heat the dye solution to 60-70 °C. Heating softens the nylon surface slightly, opening polymer chains to absorb pigment molecules.
- Soak Time: Submerge for 30 to 45 minutes with continuous gentle circulation to ensure uniform color depth across interior pockets.
- Rinse & Fix: Transfer to cold water bath to close polymer pores, followed by a UV-stabilizer wash to prevent color fading under sunlight.
A dyed SLS nylon part looks and feels like an injection molded component, ready for retail investor presentations and trade shows.
