How to Fix Pillowing in 3D Printing
For many different reasons, 3D printing technology is not without its limitations and problems. Therefore, extreme caution is required for flawless 3D printing results. Identifying the issue as fast as possible is the first step in getting reliable outcomes. After that, it's necessary to address the several causes associated with this issue. Finally, you need to figure out what to do and implement a solution.
When it comes to 3D printing services, the problem of "pillowing" is noticeable after half of the printing process is complete, which is frustrating for many people. In addition to wasting time and energy, this can also lead to resource wastage. Typically, the top layer of a 3D print will cool and cause pillowing.
How Does Pillowing Occur?
You might find that your prints are coming out with a rough, uneven, or holey top layer. This distracting flaw, known as pillowing, only appears at the very end of a print run. Inadequate cooling of the upper layers is the main culprit. The layers will distort around the infill structure below if they don't cool properly, creating a pillow-shaped pattern.
While all filaments and printers are susceptible to pillowing, certain types are more prone than others. The filament is more likely to distort when printing with small layer heights; printers that use 1.75-mm filament are more prone to this problem than those that use 2.85-mm. Furthermore, TPU and other softer filaments are frequently more severely impacted.
What is the Reason Behind 3D Printing Pillowing?
Pillowing is a particularly annoying issue because it appears only during the printing of the top layer, i.e., when the print is always finished. If you want to make sure that all of your hard work doesn't go to waste, you should be aware of the signs of pillowing and how to prevent them. So, what exactly causes pillowing?
1. Top-Layer Distortion
Anyone who has experimented with 3D printing before would recognize warping as the primary cause of pillowing. Where deformation is concerned, it is due to top-layer warping. The top layer's uneven filament distribution is caused by the material's tendency to be pulled around the infill layer immediately below it. When the distortion is severe enough, holes might appear in the upper layer and extend to the lower layer below.
2. Filaments Set to High Temperatures
Printing using high-temperature filaments exacerbates the already noticeable issue of pillowing, which is mostly a warping concern. The two most prevalent filaments that cause issues in this area are nylon and ABS. Warping, which you likely encountered on the first layer of the print, becomes more noticeable due to the drsatic temperature decrease that occurs during the extrusion of these filaments. It's annoying that warping is still an issue when the print is nearly complete. On the other hand, it just means you're more prepared to handle the same problem.
3. Soft Filaments
Pillowing problems are more common with soft filaments, such as TPU, even when printed at lower temperatures. The primary cause of this issue is the top layer's inability to become sufficiently rigid to avoid warping and maintain its shape.
Ways to Prevent Pillowing in 3D Printing
Stopping pillowing requires getting to the bottom of why it happens. To do this, you can either give the top layer something to stand on or speed up the process by which it becomes rigid. Here are a few things you can try if you're still having problems with pillowing.
1. Thicken Up the Top Layer
Increasing the thickness of the top layer improves its mechanical strength. Given the potential for warping due to heat strains, we hope this is sufficient. Making the top layer five or six times thicker than the rest of the project's layers is a decent rule of thumb to follow.
2. Maximize the Use of Infill
The infill structure can also be considered. There are two ways in which this helps. Your prints will often become thicker and more sturdy as you add support for the top layer. As a general rule, infill of at least 25% is required to avoid pillowing. A higher setting is required for the flexible filament.
While this does a decent job of preventing pillowing, increasing the infill percentage has a major drawback. It amplifies the filament input into any print beyond the effect of increasing the top layer thickness. If you're providing this service for profit, you should modify your prices so that you don't get shortchanged.
3. Speed Down the Printing Process
If you want to avoid pillowing, it's best to go slowly at first. To provide the filament additional time to cool down and harden, you can reduce the print speed. As a result, it can bear its own weight and the weight of the layers that come after it with more ease.
Remember that lowering the printing temperature goes hand-in-hand with decreasing the printing speed. We will delve deeper into that topic at a later time.
4. Make Cooling More Efficient
Improving cooling for the top layer of your project is a simple way to avoid pillowing. Warping and buckling are forms of deformation that can occur shortly after this process develops strength and rigidity. Even with the cooling fan turned all the way up to its highest level, pillowing can still happen in certain cases. A simple desk fan might be useful in this kind of situation. If you want your filament to cool down faster, print in a well-ventilated location; outside air can help.
5. Decreasing the Printing Heat
Why bother heating the filament if cooling is the issue? Keeping the top layer of your print at a lower temperature is a good move. It eases the filament's growing stiffness sooner and helps to lower thermal stress during cooling.
Reducing the printing temperature and speed are synonymous, as previously stated. To avoid an extrusion problem, make sure to change both of these values at the same time. Make sure to wait until the top layer has begun printing before doing this. Lowering the printing temperature often results in less adhesion between layers. Having said that, the top layer of a print is no longer where layer adhesion really matters.
6. Increase the Distance Between the Printhead and the Build Plate
One understated way to fix pillowing is to raise the print head's z-offset when printing the top layers. Extruded filament cools more slowly due to heat from the nozzle. Reducing the impact of pillowing can be as simple as lowering it to 0.05 to 0.1 millimeters.
Increasing the z-offset of the print head, similar to adjusting the printing temperature, can reduce layer adhesion. Remember this with every precaution you take- it is not desirable to decrease layer adhesion to an extent where the layers begin to separate.
7. Adjust the Filament Size
If you've already tried the aforementioned solutions and pillowing persists, you might want to try a different filament size. Although this is just a guess, it has been successful in certain cases. The solution to your pillowing problem can be as simple as switching from 1.75 millimeters to 2.85 millimeters. A larger-diameter filament is able to more consistently produce the filament mass required for consistent extrusion, which is why this technology is effective.
When employing a nozzle with a large diameter, the result becomes even more apparent. If you're experiencing problems with pillowing and poor extrusion, this could be a good option to consider.
Best 3D Printing Software
There are many 3D printing software available, but we recommend using SelfCAD. SelfCAD is an easy to use 3D design software that has been designed for both beginners and professionals. It comes with all the necessary tools one needs to create 3D models from scratch, editing files designed in other programs and even prepare them for 3D printing without the need for an additional software.
Some of the tools of SelfCAD includes freehand drawing and sketching for creating designs from scratch. There is also image to 3D model useful for turning your images into 3D models. It also comes with various modification tools that you can use to edit and simplify files designed in other programs, as shown below.
Once you create your 3D models, you can use the in-built online slicer of SelfCAD to slice your designs and generate the G-code to send to your 3D printer. The slicer of SelfCAD is one of the easiest, and it is compatible with most of the common FDM 3D printers. Get to know how it works in the video below.
The software also comes with many resources for learning, like the popular interactive tutorials that you can use to learn how to use the various tools of SelfCAD by actually designing files. There is also SelfCAD academy that has step by courses for 3D modeling and SelfCAD. You also have access to many YouTube videos like the 3D modeling for beginners and 3D modeling 101 playlists.
Optimizing Print Settings to Eliminate Pillowing
Understanding the causes of pillowing is crucial for finding effective solutions, as is the case with many other 3D printing challenges. Since warping is fundamental to the pillowing problem, the standard measures used to avoid warping should also serve to eliminate the problem.
Using a soft filament or printing at high temperatures might cause significant pillowing. Luckily, none of the aforementioned methods need much time or effort to implement. Making a few adjustments to your printer's preferences is all it takes. If the top layer gets too hot, you might have to bring a desk fan to your 3D printer just to keep it from overheating. Not only are they all doable, but you can maximize your results by combining two or even three of them.
Enjoy powerful modeling, rendering, and 3D printing tools without the steep learning curve.
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