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Is It Possible to Dye or Paint TPU Filament?

TPU filament is a type of printing material that combines flexibility, elasticity, and durability all in one place, and these features make it a suitable and in-demand 3D printing material. Even with these features, you might want TPU filaments to be more versatile by changing the color of the TPU filament to match what you print. That brings up the question, is it possible to dye TPU filament? 

It is possible to dye or paint TPU filament. Like other 3D printing materials, TPU filament can be painted using various types of paint like acrylic and spray paint. You can also get TPU filament in different colors and match it with paint to achieve a unique look.

The rest of this article will explain a few topics related to this question in great detail, including whether or not it is possible to dye or paint TPU filament, how hygroscopic they are and if it makes a difference when looking to dye TPU filament. We will also be looking into how you can dye TPU filament and factors to look out for when dying or painting TPU filament. 

Can You Dye or Paint TPU Filament?

3D printing is becoming more of a real deal in modern-day times. They are a more accessible and better alternative to printing materials in solid forms and shapes than other conventional methods. With the increasing utilization of 3D printing methods, there is the need for even better 3D printing materials to make results even better, one of which is the TPU filament. 

You can dye or paint TPU filament. However, not just any dye or paint is applied to TPU filaments. To be precise, you can use a digital UV dye for TPU filaments. This means with this dye, you can get the desired color, coat, or paint needed for your prospective object. 

Even though not just any paint works for TPU filaments, you can still get a good coat with a wide array of options right within your reach. 

To attain a well coated, dyed, or painted TPU filament, these two would be playing an essential role: 

  • An adhesion promoter 
  • A good primer 

With both, you can have your TPU filament painted with the desired coat with any of the following options: 

  •  Acrylics 
  • Latex-based paints 
  • Spray paints 
  • Enamels 
  • Automotive paints 

While each of these will work out pretty well, you might want to go a bit more into details of each of them and how well they last as a coat for TPU filaments. This is because they work well, but some are better than others. 

For example, if you consider a coat or dye that won’t be peeling off after a while or getting rubbed off at the slightest scratch, then acrylics, latex, and automotive paints are great options. 

To an extent, the method of painting or dying also influences how well the dye sticks to the TPU filament and how long it lasts. Thin paints certainly stay more and look better than thick coats of paint. Thick coats of paint also consume a lot more than is required. 

How To Paint TPU Filament

It is possible to paint or dye TPU filament as we have registered. However, the success of this process depends mainly on the process, and precautions are taken to get the best results. 

There are certain conditions and criteria to be met and precautions to be set in place when planning to dye or paint the TPU material. While this does not stop the material from being dyed or painted, it directly determines the end print quality. 

Here are steps on how to dye TPU filament with digital UV dye: 

  1. Prepare the dye. 
  2. Dip the TPU filament into the dye. 
  3. Take out the TPU filament. 
  4. Soak the TPU filament in alcohol. 

Here are the materials needed when you want to dye TPU filament: 

  • Dye powder 
  • Warm water 
  • Mix container 
  • Sponge 
  • Alcohol 
  • Pincers 
  • Soft cloth 

1. Prepare the Dye

Set aside a container for mix, preferably a transparent container with enough space to take the mixture and filament. Take out your dye powder and dissolve in water, mixing cleanly with a wooden spatula. 

It is advised to use warm water for faster absorption and dissolution. With cold water, the dissolving of powdered dye takes longer. Warm water should be around 40°C (104°F). 

2. Dip the TPU Filament Into the Dye

Once you have confirmed that the dye powder has completely dissolved in the water and there is an apparent saturation, you can go ahead to dip your TPU filament into the dye mix. 

One critical detail to note when looking to get the best result is that the color largely determines the time the filament spends in the dye. It varies from color to color and might require a test run first. Under normal circumstances, 30 minutes in 40°C (104°F) warm water is enough. 

3. Take Out the TPU Filament

After the wait time has been exhausted, you can go ahead to remove the TPU from the dye mix. This process requires extra care and precaution. Remove the TPU with pincers carefully and set it aside in another bowl of water to wash away the excess dye. 

4. Soak the TPU in Alcohol

After removing the TPU from the dye mix: 

  1. Rinse it with water to remove excess dye. 
  2. Soak it in an alcohol solution for about a minute or two. 
  3. After the elapsed time, take the TPU out and leave it to dry.

Is TPU Hygroscopic?

Generally, filaments are highly hygroscopic, which means they can absorb atmospheric moisture. This makes it much harder to paint TPU as it won’t stick to its surface well.

TPU is also hygroscopic since it is a filament itself which means that it can easily absorb moisture, especially under high humidity environments. This feature is both a pro and a con where 3D printing is concerned. 

For one, its ability to absorb moisture from the air in the environment makes it prone to voids and defects in parts when molding or printing. This occurs when TPU is exposed to excess moisture, which weakens the quality of the printed material. 

If you plan to use TPU material for your 3D printing, it is vital to note that its saturation level directly affects its end-product quality. In such cases, it is most advised to properly store the material to avoid over saturation due to exposure to high humid environments. A dry box with silica gel is a great option. 

Conclusion

When dyeing or painting TPU, you should take personal precautions. It includes wearing safety goggles since you will be dealing with dye chemicals. Also, wear gloves and a protective coat during the process.