Tips to Avoid Pillowing: Preventing Top-Layer Issues in 3D Printing

Understanding Pillowing in 3D Printing

It’s possible that you’ve seen that the top layer of your prints is turning out uneven, ragged, and full of holes. This noticeable and frustrating flaw is called “pillowing,” and it only shows up toward the end of a print.

This seemingly random phenomenon is caused by actual physics – when the outermost layers of plastic cool at different rates from their base layer, the top layers warp in such a way as to form a pillow-like structure. 

It can affect any type of printer and any type of filament, but some setups are much more likely to be affected than others. When the layer heights are small, for example, the filament is more likely to bend when different parts cool at different speeds. The printer builds that use 1.75-mm filaments tend to be more likely to “pillow” than those that use 2.85-mm filaments. Last but not least, soft filaments like TPU are more likely to pillow because they are more flexible. 

The Solution

Pillowing is one of the many printing issues that can be fixed in a number of different methods. The problem can most effectively be solved by utilizing a variety of these different approaches in conjunction with one another.

• Increase top layers. Pillowing can be a troublesome issue, particularly when creating prints with a top surface that is too thin.  It can easily be solved by simply increasing the top layer in the slicer to anywhere between 6 layers or 6 times the layer height. Doing this will allow for good adhesion between the print and its support material as well as reduce any warping caused by a heat build-up during printing. 
• Adjust cooling. If there is still pillowing, cooling must be improved.  it’s necessary to ensure that the cooling fans are up and running while printing the top layers. If they are active, it’s possible that they are not set optimally to properly cool down the 3D print; in this case, there are a lot of modifications available online so you can create something unique according to your printer model
  • Before you begin any 3D printing project, ensuring that your cooling fans are on is a must. If the fans are not already on, then turning them on should be your first step. Depending on your slicer, you may have the option to turn the fans on. However, if there is not an option available to do so in the slicer, then manually editing the G-code is necessary with the command M106.
• Slow it down.   Reducing the print temperature, slowing down the printing process, and increasing the per cent of infill are all options for diminishing the amount of pillow effect present. You should only use these solutions as a last resort because they can cause more problems such as reduced quality of the surface finish or slower printing times. 

The pillowing is a highly annoying flaw, but if you implement these straightforward fixes, the issue should be resolved without any difficulty.

Ganesh Divte

I am Ganesh Divte. I work as a Quality Assurance Engineer at Dhruvtara WireTech PVT LTD. I have experience in SLS, DMSL, FDM, and SLA additive manufacturing processes. I am very enthusiastic about additive manufacturing and its potential to change the way we manufacture products. I believe that Additive Manufacturing has the potential to revolutionize the manufacturing industry and make it more efficient and sustainable.