Rise flow when printing petg
It is not for all 3d printers, and not for all stl files, only when it is neccessary in need, rise the flow up to 120-150% on control panel.
We get used to printing pla, since pla is hard, easily inject for extruder , but petg is not .
Especially when you print infill, the moving is faster but flow slower, rise flow is needed.
In extreme cases, for example, when the processing temperature is as high as 250 ℃, the PLA molecular chain will be broken and dispersed into countless small molecules, from more than a dozen or hundreds of thousands of molecules to thousands, hundreds or only dozens, and the small molecules become independent small units, which are similar to liquid water from a macroscopic point of view.
In the process of processing, when PETG is coated on the screw surface, when the temperature is raised to 300 ℃, or higher, PETG does not flow out like water, but still adheres to the screw surface.
Why is PLA so popular in 3D printing industry, not only because it comes from lactic acid, from natural materials, but most importantly, it is very suitable for 3D printing. As mentioned above, PLA will flow out like liquid water when heated. It has very good fluidity under heating condition. When 3D printing, it is easier to flow out from the small nozzle and fill every detail of the model.
It is also because the fluidity of PETG at high temperature does not tend to be liquid water. In many cases, we use 3D printing PETG, which is always in under extrusion state.
We found that when printing the shells, the under extrusion state seems not to be a problem, but when printing the filling area with fast moving speed, the under extrusion is very obvious. See the photos below :
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