Layer separation is a problem not only related to eddy currents and ABS. If I have to be honest, I have repeatedly exaggerated with the remedies indicated in the article to increase the adhesion of the print to the plate.
With the result of having prints literally glued to the plate and when it came to applying a certain force to detach the object I found myself with the print in half, simply because the weak point was the adhesion between the layers and not the adhesion to the plate For this reason, while striving to bring the adhesion to the plate to the minimum necessary I also tried to strengthen the adhesion between the layers, and I report here the conclusions.
Layer Separation: Temperature
We must first of all talk about temperature, even if we must distinguish PLA (and derivatives) and ABS (and similar).
Layer Separation: Remedy for PLA
For PLA the only operation we can do is to increase the temperature of the extruder a few degrees. Even just ten degrees can change greatly the mechanical strength of the print. I have personally noticed that the increase in temperature of even many degrees of the PLA does not compromise its appearance, and solidifies its mechanical strength, always on condition that it does not detect the problems of stringing that at a certain point may occur.
Layer Separation: Remedy for ABS
For ABS the matter is a bit more complicated. With this material you have to be rather careful because the separation of the layers can be done autonomously and there is no need for any mechanical force. In addition to the temperature of the nozzle, which must be kept constant throughout the press we must also worry about the temperature of the object itself.
The ABS expands with the heat and withdraws cooling, for this reason we must cool the object in the sweetest possible way. Not only does the heated plate allow the ABS to adhere to the printing plate, but the diffused heat, better if in a printer with a closed chamber, does not allow the object to cool quickly and keeps it intact.
A final recommendation in this regard is: Beware of draughts! A single small draught that suddenly lowers the temperature of the object can have devastating consequences for the press and reduce it as in the picture!
Layer Separation: Non-proportioned layer to the nozzle out hole
A much rarer reason, and one that comes exclusively from human error, is to set the layer layer too high.
Can it happen that the haste pushes us to want to print quickly and what better way to increase the layer? This is not always a good idea, especially if you don’t respect the 4/5 rule. In essence, this rule says that the maximum layer that can be set is equal to 4/5 of the nozzle diameter.
To give some practical examples we can say that if you use the nozzle with a diameter of 0.5 mm the highest height of the layer that can be set is 0.4 mm. For the 0.4 mm nozzle size it is 3.2 mm and so on. If we wanted to print a 0.5 mm layer with a 0.4 mm nozzle we would immediately notice that the melted material would not be properly coated on the previous layer. So it would not adhere properly and would crumble to the touch.