3D printing using thermoplastic polyurethane (TPU) can offer you flexibility, durability, and abrasion resistance in any end-product that you choose to design. Although it is a very popular printing material due to its practical features, many users hesitate to use it because they don’t use a cooling fan in their workspace. But do you actually need cooling when working with TPU filament?
TPU filament needs cooling, but only when you’re printing at high speeds or a temperature higher than 482°F (250°C). Fans are not always necessary, and even when in use, a setting below 50% is enough to keep your material cool and adequately printable.
In the following sections, I will explore when and why your TPU filament needs cooling and the ideal temperature you should use when using TPU. I’ll also cover whether you’ll need ventilation when printing with TPU and other hardware requirements you may have.
When Does TPU Filament Need Cooling?
Whether or not you’ll need cooling fans when 3D printing with TPU filament depends heavily on the settings you’ll be using and the specific brand of TPU material.
TPU filament needs cooling when printing at higher temperatures and speeds, at which point you will need to use a part cooling fan. However, if you opt to print at slower speeds and your nozzle has a lower temperature, using fans would make no notable difference in the print quality.
If you choose to use a cooling fan when 3D printing, a 30-40% setting is adequate for most situations. You need to cool the TPU filament when printing at higher temperatures because cooling will help harden the material.
This means that the following layer will have a solid, supportive foundation to layer on. If the TPU gets too soft, your print won’t have enough structural integrity, and the whole process will become messier and less effective. Fans would also be ideal when printing bridges with TPU filament.
Likewise, if you’re printing at higher speeds, the material will have less time to cool, resulting in the same undesirable situation that I described above. Going slower is almost always advisable for general print quality and durability when it comes to speed. So, if possible, try to take your time with the printing process.
On the other hand, if your nozzle has an adequately low temperature and you’re printing at a lower speed, using fans will make little to no difference to the process. This means that it is entirely possible to work with TPU even if you don’t own cooling fans – you just will have to be a bit more careful when it comes to the print’s settings.
Not only can cooling fans be ineffective, but in some cases, they can also negatively affect the final object. When using stronger settings, there is a possibility that the fans can cause warping and distortion in the TPU layers. The added air pressure can also dry out the material and make it brittle and less durable.
Unnecessary cooling fans can disrupt the adhesion process as well. TPU filament often requires more time for the adhesion between layers to set due to its flexible nature. This means that, when used unnecessarily, cooling fans can harm the printing process.
So, before you decide on whether or not to use cooling fans in your next TPU printing project, consider your temperature and speed settings, the quality of ventilation, environment temperature, etc.
Making the right decision regarding the usage and the strength of cooling fans can significantly distinguish between a successful and a failed print. When it comes to 3D printing, this difference can be pretty costly and time-consuming.
What Is the Ideal Printing Temperature for TPU?
The ideal printing temperature for TPU hovers around 437°F-482°F (225°C-250°C). The right temperature depends on external conditions, your ventilation system, and the type of 3D printer you’re working with.
When choosing a temperature, you should keep in mind that, while opting for higher temperatures can allow the filament to flow more easily and melt faster and more smoothly, it may also hinder your print’s structural integrity. So, try to play around with the temperature setting to decide which level works best with your specific conditions.
Does TPU Filament Need Ventilation?
Ventilation is always necessary when printing with TPU filament. A well-ventilated area is a must when 3D printing, as most materials (including TPU) can release toxic fumes when they come in contact with other elements. These fumes can be harmful when inhaled regularly.
The chances are that you will not suffer any serious damage when 3D printing once or twice in an enclosed area. Having said that, regularly inhaling small doses of toxic fumes can be a health hazard, so try to err on the side of safety. Whenever possible, try to print in a well-aerated space and make several air changes throughout the process, ideally even multiple per hour.
Other Hardware Requirements
To get the best possible results when 3D printing with TPU, you will need to consider many more factors aside from fan usage.
When it comes to speed, TPU requires a slower process. Depending on the printer model and material brand, the ideal printing speed can fall anywhere between 15-30 mm/s (0.59-1.18 inches). While a setting this slow may seem like overkill, in reality, it is essential in getting high-quality and detailed parts and prints.
The best retraction settings for TPU require a distance that falls within the range of 0.5-2 mm (0.01-0.07 inch) while requiring a retraction speed of 10-20 mm/s (0.39-0.78 inch). Lower retraction settings are ideal for working with a soft and flexible material, such as TPU.
Direct Drive is most commonly recommended when it comes to the ideal type of extruder you can use for TPU filaments.
Another important requirement you should consider is the print bed’s temperature settings. TPU tends to deliver the best results with a heated print bed at around 104°F-140°F (40°C-60°C).
You won’t always need cooling fans to produce a detailed, high-quality part when using TPU filaments to 3D print objects. Cooling is only necessary when printing on higher temperature and speed settings. Otherwise, using fans when not required can be inconsequential at best and damaging at worst.
This is why speed, temperature, and other crucial factors (like ventilation, retraction settings, external conditions, and so on) should all be considered before you decide how you should use a TPU filament on your print.
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I started 3D printing since 2013 and have learned a lot since then. Because of this I want to share my knowledge of what I have learned in the past years with the community. Currently I own 2 Bambulab X1 Carbon, Prusa SL1S and a Prusa MK3S+. Hope you learn something from my blog after my years of experience in 3D printing.