Should You Print TPU (Flexible Filament) on a Glass Bed?

Whenever you switch to a new filament for the first time, there are numerous challenges you have to go through to ensure that the filament prints without problems, as every filament has a unique set of properties that cause it to behave entirely differently than the others.

While configuring the print settings on the slicer software make up for the majority of these challenges, staying on top of the physical side of things is also just as vital, with essential factors such as bed adhesion requiring everything to be in order.

Today, we will try to discover how the combination of TPU, also known as flexible filament, and a glass print surface work together, as the compatibility between the filament and the build plate is one of the most vital factors to consider before printing to avoid issues down the road.

So, should you print TPU on a glass bed?

A glass bed is widely considered the best surface for printing TPU (flexible) filament, as the natural strength of adhesion between these two materials is perfectly balanced to the point where you will neither face issues with the TPU not adhering correctly nor have problems with it getting stuck.

Moving forward, we will take a deeper dive into finding out whether it’s feasible to print TPU on a glass bed or not, discuss the strategies we can apply to get TPU to adhere better to a glass bed, and take a look at how we can remove TPU from a glass bed without damaging anything.

Should You Print TPU (Flexible Filament) on a Glass Bed?

Glass build surfaces are perhaps the most common choice in the 3D printing world right now as they play well with PLA for the most part, but as you may predict, this doesn’t mean that the combination of TPU and glass is guaranteed to produce good results.

Printing TPU on a glass bed is perfectly fine, as a glass bed is actually the best surface for TPU to adhere to without creating any problems in either sticking way too firmly or not sticking firmly enough and causing bed adhesion problems.

If you print with TPU filament regularly or are planning to do so, we highly recommend investing in a glass bed for a better experience and higher quality prints, especially if you currently only own a PEI bed, which is entirely unsuitable for printing TPU.

As both borosilicate and tempered glass beds are perfectly suitable for printing TPU, feel free to pick the one that suits you best in terms of use cases and budget.

How to Get TPU to Adhere Better to a Glass Bed?

While you shouldn’t face bed adhesion issues while printing TPU on a glass bed, there are some tips and tricks you can apply to increase the strength of the adhesion for scenarios where you can’t get the plastic to stick to the surface.

Below, we have listed the solutions you can apply to get TPU to adhere better to a glass bed:

  • Clean the glass bed – A glass bed that isn’t clean is highly likely to create adhesion problems, which is why we highly recommend cleaning it with warm soapy water now and then, especially if you are switching between different filament types frequently.
  • Reduce the initial print speed – With an initial print speed value that falls in the range of 25% to 50% of the standard print speed, the 3D printer will have enough time to print the initial layer correctly while also giving the layer enough time to form strong bonds.
  • Increase the initial print temperature – With an initial print temperature value that is 10 to 15 degrees higher than the standard print temperature, the filament will be able to flow smoothly during the printing of the initial layer and adhere firmly to the bed.
  • Increase the initial layer height – A slightly (20-25%) thicker initial layer height will cause the initial layer to contain more plastic, strengthening its bonds with the bed.
  • Increase the bed temperature – An increased bed temperature value will prevent the first layer from cooling down and solidifying before it can form strong bonds with the bed, increasing the force of adhesion.
  • Decrease the cooling fan speed – We can consider decreasingthe fan speed or even entirely shutting off the cooling fan to be common practice during the printing of the first layer, which will give the plastic more time to form strong bonds with the build surface.

As these solutions would apply to pretty much any scenario in 3D printing, regardless of the type of filament and the bed you’re using, you can also feel free to apply them if you aren’t using TPU or if you aren’t printing on a glass bed.

How to Remove TPU from a Glass Bed?

Removing plastic that is stuck to a glass bed is always a tricky process due to the glass being highly susceptible to scratching and even cracking during the removal process, but fortunately, you can avoid these problems by following the correct methodology.

To remove TPU stuck to the glass bed, we would highly recommend using the freezer method, where you insert the glass bed into the freezer in 10-minute intervals and try to gently pull the plastic off the glass bed after each interval.

This process will eventually cause the glass to release the plastic due to contraction, and the model will pop right off the glass without the need to apply any excessive physical force.

While it’s possible to apply different methods, such as scraping the TPU from the glass bed with physical force, we don’t recommend such methods as they are likely to cause damage to both the glass bed and the model you have printed. 

Do You Need a Heated Bed for Printing TPU?

As it’s not possible to find heated beds in every 3D printer, knowing whether the filament you intend to use will print correctly without a heated bed or not is vital to ensure that you don’t face any issues during the printing process.

While we would highly recommend utilizing a heated bed for printing TPU to ensure that you don’t face problems with bed adhesion, it’s also entirely possible to achieve successful prints without a heated bed since TPU is considered a type of filament that is highly unlikely to cause warping issues.

On the other hand, it’s worth noting that as the primary purpose of a heated bed is to ensure that the plastic cools down evenly, the chance of experiencing problems due to the absence of one increases as the bottom area of the model gets larger.

Wrapping Up

Finding the build surface material that plays well with the filament you’re printing can definitely be a challenging task, especially considering that combining the wrong surface and the wrong filament can cause catastrophic results.

To quickly recap, you can indeed print TPU on a glass bed without any issues, and in fact, we can consider a glass bed to be the most suitable option for printing TPU as it provides the perfect environment for TPU to adhere strongly enough not to cause issues, but not too strong to get stuck to the surface.

While rare, in the case you’re facing issues with the combination of TPU and glass, going through your slicer settings and ensuring that everything is in order will most likely solve your problems, as printing TPU on a glass bed should not require any extra measures for success.

Happy printing!