Why does delamination occur in 3D printing?
"Delamination, or the separation of layers, usually occurs as a result of poor adhesion. In addition to between the first layer and the build platform, poor adhesion can also occur between all other layers during 3D printing. This is what we call delamination."
"Layer separation can lead to serious defects in the model you are printing. This problem arises due to several reasons, including too low temperatures, overheating, high layer height, and others."
In the following lines, you will understand the different reasons for experiencing delamination and how to prevent it.
How to prevent layering in 8 easy steps?
1. Clean the heater.
"After prolonged use, your heater may become dirty or even clogged. Partial or complete clogging would lead to serious difficulties in extrusion. In particular, the reduction of extruded material may weaken the bond between layers, causing issues such as layer separation."
Periodic cleaning of the heater will prevent such clogging. This is done by heating the hot end to the usual temperature at which you print and removing all accumulated deposits.
Meanwhile, clean the nozzle using a metal pin or needle.
This step is recommended as a preventive measure, even if you are not yet observing layering in the patterns you are printing.
2. Reduce the speed of the 3D printer.
Reducing the printing speed is a common solution for a number of issues, including delamination. This gives the heater more time to melt the filament and for the individual layers to fuse together.
When adjusting, reduce the printing speed in increments of about 5-10 millimeters per second, depending on the 3D printing material you are using, until you reduce it to about 50% of the initial value.
"In case there is still stratification, the problem is likely hidden elsewhere."
3. Increase the temperature of the heater.
The increase in the temperature of the hot end should enhance the extrusion of the model you are printing.
When the temperature of the heater is too low, the filament does not have enough time to melt. This causes issues such as insufficient extrusion.
Keep in mind that the temperature of the hot end affects how well the individual layers bond during and after the 3D printing process. A higher nozzle temperature results in stronger parts.
"Also, the hotter nozzle produces a greater flow of filaments. This additional material increases the bond between the layers."
"To improve the stability of the bond between the individual layers and to prevent delamination, initially try to increase your temperature by about 10°C. If the problem persists, continue to raise your nozzle temperature in increments of 5 degrees."
Do this until the problem disappears, until you reach the temperature capability of your printer, or until you exceed the temperature range of FDM filament.
4. Increase the flow rate.
The flow rate determines how quickly the extruder feeds the filament into the hot end. Increasing this speed in the 3D slicer is another possible solution to the problem.
"Before you do this, however, make sure you have correctly set up the E-steps of your 3D printer, as flow and E-steps go hand in hand."
As the flow rate increases, the amount of strands pushed through the nozzle also increases. As we mentioned earlier, more extruded material means more opportunities for layer bonding.
"In case you decide to take this step, do it in increments of 5% until the problem disappears. However, if you start to experience excessive oozing, then the flow rate is not the cause of the layering of the models you are printing."
5. Adjust the cooling of the parts.
Just as excessive airflow can cause distortion of the first layer of parts, excessive cooling can separate the layers of the model. If the layers cool too quickly, the bond between them weakens, which can lead to delamination.
To resolve this issue, reduce the fan speed for partial cooling in increments of 10%. Do this until the problem disappears or other printing errors occur.
Don't be afraid to reduce to 0%, especially when working with cooling-sensitive materials like ABS(Acrylonitrile butadiene styrene). Using a fan when working with PETG(Polyethylene terephthalate glycol) can also lead to poor adhesion.
The airflow is primarily produced by the partial cooling fan of your printer. However, it can also come from unintended drafts.
To determine if this is the cause of delamination, print a test piece at a low fan speed while keeping your printer in a controlled environment, such as a closed room, to block airflow. If you do not see layer separation, then it is excessive cooling that is causing delamination in the models you are printing. In that case, it is advisable to build or purchase an enclosure for your printer.
6. Reduce the height of the layers of the 3D model.
Layer height represents the distance upward along the Z-axis at which the print head moves before starting to build a new layer. It is defined in relation to the diameter of the nozzle. A commonly used layer height for a 0.4mm diameter nozzle is 0.2mm.
The smaller the layer height, the more details your 3D printer can build. Accordingly, the larger this value, the stronger the 3D models will be.
If the layer height is set too high, the individual layers will not be close enough to bond effectively, which may potentially cause delamination. If you are using a standard 0.4mm nozzle with a layer height above 0.2mm, try to reduce the height to that value.
"If there is still layering, reduce the height a little more. But if you reach a height of 0.16mm and there is still no result, you need to try one of the other steps."
7. Change or dry the thread.
When exposed to moisture, FDM filaments usually lose their quality. This happens because the material degrades and as a result, it becomes more difficult to print. More hygroscopic materials, such as TPU (Thermoplastic polyurethane), go through this process faster than others.
If the filament you are using is wet, try printing with a different filament before finishing your project.
Using dry filament can help prevent delamination as well as other quality-related issues. You can do this by using new filament or drying your current one. Once you dry your filament, store it in an airtight container to prevent moisture from entering. For this purpose, it is easiest and most convenient to use a special dry FDM filament box from Creality.
8. Use a wider nozzle.
"If none of the steps taken so far have helped to address the issue of separation between the layers, using a nozzle with a wider diameter may do the trick."
"The diameter of the nozzle can also affect the adhesion between layers. In many cases, the larger the diameter of the nozzle, the better the adhesion."
A nozzle with a larger diameter will result in wider lines of melted filament, increasing the surface area for the next layer to bond to. Accordingly, if you increase the layer height, there will also be fewer opportunities for delamination, as fewer layers will be needed to create the given part.
Typically, most 3D printers use a nozzle with a diameter of 0.4mm. Using a 0.5 or 0.6mm nozzle can prevent layer separation. However, before moving on to this step, try one of the aforementioned methods to address the issue. This way, you would avoid a potentially unnecessary purchase of a larger nozzle.
"If you decide to increase the diameter of your nozzle, don't forget to adjust the temperature and flow rate to compensate for the increase in extrusion."
