Dyeing and Tinting

p/n 33-D211 Rev A

 

Dyeing and Tinting

 

Many customers may desire to add color to their parts. Very small features and printed assemblies can be difficult to paint with traditional methods. Fortunately, the MultiJet materials can be dyed or tinted very easily with off-the-shelf dyes.

The system was designed with three clear materials that all can be easily dyed and which span a wide range of material properties from PC-like, to ABS-like and polypropylene-like. In addition, the EasyClean post processing system is also a great tool for dyeing the parts.

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Printed bearing, threaded screw and mesh assembly

Center, Rigid Clear M2R-CL, M2G-CL Armor and M2G-DUR ProFlex

Outer ring, M2R-CL dyed with 1% concentration (60C and 30min)

 

MJP Dyeing and Tinting Overview

We suggest using synthetic dyes for dyeing MJP parts.  Specifically, we used synthetic Rit DyeMore dyes. These are listed as fabric dyes for materials such as nylon and polyester, but the chemistry works well for MJP acrylate materials. The following are 12 synthetic dyes available from Rit.

These dyes are easily purchased on-line form companies like Amazon or Walmart and can be found at most hobby/craft stores.  

Graphite (black)

Frost Gray (gray)

Chocolate Brown (brown)

Sand Stone (light pink)

Super Pink (bright pink/magenta)

Racing Red (automotive red)

Apricot Orange (automotive amber)

Daffodil Yellow (light yellow)

Peacock Green (blue/green)

Kentucky Sky (light blue)

Sapphire Blue (Blue)

Royal Purple (Purple)

 

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Twelve Synthetic Rit Dyes available from Amazon, Walmart, and fabric and craft stories.

(images from www.ritdye.com)

 

Rit web site also teaches how to mix colors into much larger color spaces.  Hundreds of colors are made through dye mixing.

img 3_dye mixing.jpgRit colors made through dye mixing

 

Colors can also be mixed according to basic color science, examples of which can be found with simple searches from the web.  A trial and error method using small printed parts is suggested.

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Mixing colors examples

 

 

Preparing the 3D Printed Part

There is not much that has to be done to the part aside from following the basic MJP post process. Be sure to remove all the support wax and clean with a solution of Dawn soap followed by a warm water rinse. Surface uniformity can be improved by brushing the surface with a stiff nylon brush. An even higher quality surface with longer shelve life can be achieved by using a dry glass bead blasting after the post process. Use 40 to 90 nominal diameter micron range small glass beads with a 60-80 psi pressure on the entire surface. A water vapor honing process is recommended for higher quality and/or larger volume of parts.

 

 

Heating and Dyeing Equipment

One can use almost any watertight container to dye an MJP part such as a glass, metal or plastic. Heating can be accomplished with a direct contact gas or electric stove, with a microwave or by simply placing the dye containers in an oven. For example, the ProJet finisher can be used for dying MJP parts.

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ProJet Finisher oven is an excellent tool for dyeing MJP parts

 

Make sure the container is compatible with the heating system (i.e., no direct heating on plastic and no metal in a microwave, etc…). After used for dyeing, it is best to keep all of the materials separate from any normal food containers and only use these containers for dyeing. Label things clearly for safety and simplicity.

For normal post processing, the EasyClean system offer convenient, fast, and automatic turnkey removal of support material from plastic and elastomeric parts produced on ProJet MJP 2500 3D printers.

img 6_easyclean.jpg

Fine Wax Remover                 Bulk Wax Remover

MJP EasyClean System

The EasyClean system utilizes two warmer units (bulk wax remover and fine wax remover) that use steam and EZ Rinse-C (and/or common mineral oil) to melt wax supports away, without manual labor. It is intended to operate in a typical office environment, resting on a table, without objectionable noise or odor, and without requiring special ventilation or equipment, only requiring access to a sink. The system can hold a part as large as the full build size and can be left active throughout the day for simple and high-volume post processing of parts. The standard operation of the system can be found on the 3D Systems Infocenter.  While many methods are possible for dyeing, the EasyClean post processing system is an excellent tool for dyeing parts.  For dyeing standard polypropylene tubs, metal pots, or ceramic cups can be heated in the fine wax removal warmer.  Simply fill the 2/3 size stainless steel container with hot tap water up to about 1/3 full. Select containers sizes based on your desired part size and number of colors. Two convenient configurations are to use six smaller 1-liter containers or three larger 2-liter containers. Once the containers are filled with the water and dye solution, they will sink and rest firmly in the warmer. The solution preparation is explained below. Set the warmer to level #4 and cover the warmer with the lid. Level #4 will achieve a temperature of about 60C, which is a good temperature for Dyeing MJP parts.

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EasyClean System with a) 6x 1 liter containers and b) 3x 2 liter containers

 

 

Preparing the Dye Solution

One must figure out how much liquid is needed to completely submerge the part. If possible, we suggest using 1 liter or 2 liter containers as shown above and are readily available at most painting or hardware stores or can be ordered online through numerous vendors including Amazon.com. While some experimentation may be needed for specific effects and colors, we suggest using a 1% or 2% mixture of dye with hot tap water. Start by filling the container with hot tap water (~50-60C) making sure to leave sufficient room for the part to be fully submerged and then add 1% or 2% dye to the container. Finally, add just a drop of liquid soap such as Dawn dishwater soap. The Dawn soap reduces the surface tension of the mixture and keeps bubbles from sticking to the parts. Air bubbles cover the part and do not allow the water and dye mixture to contact the part resulting in undyed regions/spots on the part.

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Light spots created by air bubbles sticking to the part

 

A water and dye mixture example is shown below where 1 liter (1000 ml) of hot tap water mix 10 ml of dye.

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1% Dye Concentration (1-liter hot tap water mixed with 10 ml of dye)

 

Place the dye, water and soap mixture into the appropriate containers leaving room for the part. Let the system stabilize to about 60C. If the system was filled with hot tap water, this will only take a few minutes. If cold water was used, it might take about 1hr for the entire system and dye solutions to reach a steady 60C.  For best results, we suggest setting and measuring the dye solution temperatures to 60C. Higher temperatures can be used, but may cause the part to warp. Lower temperatures can be used, but will take more time to achieve a given color. The dye and soap droplets can be added to either room temperature or hot water.  The dye is mixed easily with the use of a mild stir with a spoon or stir stick. Avoid aggressively stirring the mixture as this will generate bubbles that could stick the part.

 

Dyeing the MJP Part

While these dye mixtures are not aggressive to skin contact and will not tint the skin much with brief contact, they will stain clothes. It is always best practice to use appropriate protective equipment such as gloves. It is best to handle the parts with some type of pliers like those that are traditionally used for food serving.  A strainer can also be used to place and retrieve the parts from the dye solution. Pick up the part with the pliers and place it into the dye solution. Any bubbles will also leave undyed regions on the part. Make sure that the part does not trap any bubbles. Leave the part in the solution for about 15 to 30 minutes. The longer the parts are left in the solution, the more saturated they will become. At 60C, the parts will become completely saturated in about 1-2 hrs. Thinner parts saturate faster than thicker parts. The part should be left in the mixture for as short as time as possible to avoid changing the material properties of the part or causing geometric distortions.

img 12_sample keychains.jpg

Clear

 

White

 

Clear

 

Clear

Clear/White Color Saturation, 60C 30min, 20min, 10min, 5min, 2min

Sapphire Blue, Super Pink, Peacock Green

Royal Purple, Apricot Orange, Racing Red

 

If you have multiple parts in the solution, avoid them touching each other and/or the bottom or sides of the container. The parts will not dye well at any locations of physical contact.

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Light regions caused by parts touching each other or touching the container

 

 

Dyeing Remove, Rinse and Dry the Part

Remove the part using the tongs/pliers and avoiding skin contact. Rinse the part under warm water to clean off any excess dye/water solution. After a good water rinse, rub the water off the part with a dry paper towel. You want to remove as much of the dye/water mixture from the part as possible. Any dye/water liquid you leave on the part will evaporate away and leave a small amount of dye on the surface of the part that could transfer off to your hands or clothes or to other parts in an assembly, etc… Finally, place the parts on a paper towel and let it dry. The dye will stick aggressively to the part and will not come off easily. In addition, as long as you removed all the water/dye solution from the surface of the part and rinsed it well, the part will not tend to mark other parts, clothing or hands…They can be cleaned, rubbed and wiped and the colors will not transfer.

 

MJP Dying/Tinting Tips and Tricks

  • Use more dye (2% vs. 1%) for any of the colors that are lighter in color (like the Daffodil Yellow, Kentucky Sky, Frost Gray and Sand Stone)
  • Use a small drop of Dawn dish soap in each dye solution to eliminate bubbles sticking to the part that cause color uniformity issues.
img 14_blue tag_white dots.png

Light spots from air bubbles sticking to the surface

 

 

  • Do not keep metal strainers in the dye solution for extended periods.  The dye will form precipitates on the metal and will reduce your dye concentration and result in particles in the solution.
  • Do not keep the dye solutions heated for any longer than is needed to dye the parts.  Turn the warmer off nightly.
  • Do not let the parts touch each other or touch the container bottom or side.  This leaves a light area at the point of contact.

 

img 15_light spots.png img 16_light spots.jpg
Light defects from parts 1) touching eachother and 2) resting on the container bottom

 

  • When dyeing a large number of parts, it can be advantageous to periodically mix the parts to avoid any contact defects.
  • You can store the dye for use later, but typically, more dye will be needed each time a batch is reused.  The first time being used, plastic containers will absorb a lot of dye.
  • You can dye parts with just a microwave.  Place the mixed dye and water solution in the container and heat it in the microwave.  Remove the container and place the part into the container.  Repeat as needed for correct color saturation.
  • Some dyes will form small precipitates over time if left standing.  These can sometimes be filtered out using mesh or traditional paper filters.  Sometimes it is better to just remix the solution with new water and dye.  This is particularly bad for orange, gray and black.
  • Thoroughly rinse the parts to remove all the dye from the part.  Any dye left on the surface can transfer off to fingers and/or other parts in an assembly.
  • Rigid white (M2R-WT) can take about twice the time to dye compared to the rigid and engineering clear materials.  It might take 30min to 1 hr to achieve a good color on a white part.

 

 

MJP Dyeing Examples

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Rigid clear (M2R-CL) automotive lenses dyed with standard colors with 1% concentration (60C and 30min).

 

 

img 18_dyed storage containers.jpg

Polypropylene-like storage containers made with M2G-DUR (ProFlex) dyed with standard colors with high saturation 1-2% color concentration (60C and 2hr).

 

 

img 19_dyed keyrings.jpg

Rigid clear (M2R-CL) color keyring with clear coating dyed with standard colors with 1% concentration (60C and 30min).

 

 

img 20_lens dyed clear.jpg

Left: Daffodil Yellow, Center:  Green, Right:  Peacock Green

Green was created with 1% Peacock Green + 3% Daffodil yellow (60C and 30min).

 

 

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Polypropylene-like storage containers made with M2G-DUR (ProFlex) dyed with standard colors by using a mixture of 1-2% concentration (60C and 30min)

 

 

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Darker (tertiary) colors created by mixing standard color dyes with gray.

  • 1st row 1% color concentration (60C and 30min)
  • 2nd row 1.5% color and 0.5% gray concentration (60C and 30min)

  • 3rd row 0.5% color and 1.5% gray concentrations (60C and 30min)

 

 

img 23_Prolex containers.jpg

Polypropylene-like storage containers made with M2G-DUR (ProFlex) dyed with darker colors by using a mixture of 1.5% color concentration and 0.5% gray (60C and 45min).

 

 

img 24_Proflex storage container.pngPolypropylene-like storage containers using entrapped support in the build material for text/graphical marking of the part. Made with M2G-DUR (ProFlex) dyed with dark colors by using a mixture of 1.5% yellow and 0.5% gray (60C and 45min).
 

 

 

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ABS-like injection moldable quadcopter frames made with M2G-CL (Armor) dyed with standard colors with 1-2% color concentration (60C and 1hr).

 

 

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Color assembly created by dyeing the individual parts followed by assembly

Standard colors, 1% concentration, (60C and 30min).

 

 

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Highly complex shells and infill (3D Sprint) part followed by dyeing.

Standard colors, 1% concentration (60C and 1hr).

 

 

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Auto lenses dyed with all 12 of the standard Rit Synthetic dyes followed by clear coating.

Standard colors, 1% concentration (60C and 30min).