We all know, parts should stick to the build platform when finished in bottom-up SLA/DLP/LCD 3D printer.
When there are no parts or just fragmentary ones on the build platform, we need to check your issues before restarting. Sticking to the Vat surface is one of the most common printing problems in bottom-up SLA/DLP/LCD 3D printing.
In order to solve sticking problem, we need to understand what factors will lead to parts sticking to the vat.
The first thing to make sure is that in slicing software, the parts are going to be attached to the build platform and not suspended. You need to pay attention to some models that may be suspended in some positions which are likely to cause the problem of sticking to the FEP.
In some slicing software, the surface will appear green when the bottom is attached, and there will be no colour change for any parts not touching the build plate.
In addition, the build platform needs to be precisely levelled and the contact with the FEP film should not be too loose or too tight as it may lead to sticking or other printing problems.
Also if the build platform is not cleaned properly there could be oil or other impurities on it, also if the build platform is worn or damaged this could lead to the reduction of the adhesion resulting in failed prints.
Bottom Exposure Time
The bottom exposure time is recommended to be at least 8-12 times the normal exposure time. Only in this way can any possible gaps between the build platform and the FEP vat be fully cured so that the first layer is firmly attached to the build platform. If the bottom/raft can't stick to the build platform, you need to increase the bottom exposure time. Generally, the longer the bottom layer is exposed, the more firmly the bottom/raft sticks to the build platform.
Lifting speed refers to the lifting speed of the build platform from the vat which can also be referred to as the peel speed. If the lifting speed is too fast, the part may be pulled down to the FEP vat due to the peel force/separation force.
If the Fep is worn or too loose or even too tight, it may affect the peel force, resulting in the sticking problem.
3D Part Itself
The editing of the part itself, such as improper placement of the angle, hollowing, punching, etc. may result in excessive peel force/separation force, which may also lead to sticking.