Prints and Samples
#3DBenchy, the 3D Print Benchmark model
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Think of it like the whole suction cup on a plate concept.
It is very hard to pull a suction cup off a plate perpendicular to the plate. But if you slide the cup along the plate, it is easier to break the vacuum. The same principle applies here. The PDMS layer gives some flex to the FEP layer, so it will pop off easier than if the FEP was directly applied to the acrylic. My iBox Nano peels via almost a direct pull method from the FEP/glass plate and it is very violent, resulting in separation from the plate if you do not have enough of a foundation covering the build plate and it can't print fine, thin detail without breakage.
See printers that use a sliding motion to release (B9Creator, Autodesk Ember) for what is believed to be the least 'abusive' peel method.