Loss of micro-features is a frequent issue in vat photopolymerization printing where small details disappear or merge during the printing process. The defect typically affects thin walls, sharp edges and intricate surface patterns.
Although often attributed to printer resolution limits, the phenomenon is usually related to curing behaviour and optical propagation within the resin.
Physical causes of micro-feature loss
Excessive cure depth
When the cure depth of the resin exceeds the intended layer thickness, polymerization spreads beyond the designed geometry. As a result, adjacent structures may merge or small voids may close.
Optical diffusion
Light scattering and optical diffusion may cause the projected image to expand laterally inside the resin, blurring fine structures.
Overexposure
Exposure times that are too long increase the degree of polymerization beyond the intended boundaries, reducing feature resolution.
Typical visual symptoms
- micro-channels closing during printing
- loss of thin walls
- rounded micro-edges
- small holes disappearing
Typical corrective strategies
- reduce exposure time
- decrease layer thickness
- improve optical attenuation in the resin
- optimize part orientation
Engineering perspective
Micro-feature reproduction depends on the balance between printer optical resolution, exposure calibration and resin photopolymerization kinetics.
For a broader classification of defect morphologies see the 3Dresyns® Photopolymer Printing Failure Atlas .