When an STL file’s 3D model peels in a slicer, it’s typically due to non-manifold geometry or low mesh resolution—both disrupt the slicer’s ability to read continuous surfaces.
- **Non-manifold geometry**: The model has "broken" connections (e.g., overlapping faces, unclosed edges) the slicer can’t interpret. - **Low mesh resolution**: Too few triangles create jagged edges that split during slicing.
Fix it by using your slicer’s built-in repair tool, free software like Meshmixer for non-manifold issues, or re-exporting the STL from CAD with a higher triangle count to smooth the mesh.