Colour Options for 3D Printing

When it comes to finishing of 3D printed parts for either prototypes or manufacture, a small number of coloured materials are available, but most colouring options require treatment at the finishing stage rather than the manufacture stage.

These options include:

• Coloured materials
• Spray painting or by hand
• Dyeing

Each colouring process has its benefits and drawbacks. Yet dyeing of SLA and SLS parts is comparatively rare.

Prototype Projects has now developed its own proprietary method of dying 3D printed parts which it can offer to clients.

Variables in the dyeing process

The main variables in dyeing of SLS parts are the choice of dye material, which is usually acid-based, and the timing of part immersion, colour fixing and cleaning processes.

The temperatures at which the dyeing and fixing are most efficient are also critical as is the  nature of solution stirring or agitation.

When to use dyeing rather than spray painting with SLS parts

Typical SLS parts have complex geometries which may be difficult to colour, largely due to the accessibility of the surface. Where these areas cannot be accessed by paint, the dyeing process will ensure 100% colour coverage.

As SLS parts are typically porous, the dye colour can soak into the surface which means that any scratching is less likely to reveal the base colour.

Finally dyeing is preferable if the size of the part is critically important, as painting will typically add an extra layer of thickness to the surface.

The SLS dyeing process

All dyes are applied to SLS parts as part of the finishing process. All smoothing and blasting is completed before dyeing commences, so that colouring is the final element of the part manufacturing process.

Dyes for all primary colours are readily available: yellow, violet, and red, blue and green for which shades are available. Black is offered as a mixed colour.

All colours can be applied to your SLS part. For colour other than a primary colour, Prototype Projects can mix your colour to achieve the required match.

After production and preliminary finishing, SLS parts are immersed in the heated dye solution which is agitated for a period of hours.

Having been immersed in the dye for the required period, it is removed and washed separately in a cleaning solution to remove excess dye, at which point a levelling solution is added to aid with fixing the colour.

Finish

Lighter or darker shades of colour can be achieved depending on the dye mix and density of material. With SLS parts, the dye colour typically penetrates to a depth of 1mm giving the part a scratch resistant property.

Once the SLS part has completed the washing process, it is removed from the cleaning solution for drying and is ready for delivery once completely dry.

For most parts, no further finishing is required though for parts in black and primary colours a further light blowing over is possible to add density to the colour.

View information on our 3D printing technologies – SLS Rapid Prototyping, SLA Rapid Prototyping and FDM Prototyping.

Find out more

Talk to us about your next prototype project contact us on 01763 249760 or click here to request a quote.