Occlusion-based model weighting for volumetric additive manufacturing around inserts

Additive manufacturing is used to add polymer material around pre-existing inserts in many patient-specific and case-specific applications. Tomographic Volumetric Additive Manufacturing (VAM) technology is a suitable process for printing around inserts. Here, a weighting method for print models in VAM is proposed based on occlusion of light when printing around inserts. Benchmarks with various insert occlusions are assessed, different projection computation algorithms are evaluated and the negative effects of voxelisation of inserts are discussed. A new metric is proposed for assessment of print quality and the utility of different projection computation algorithms, and the effect of weighting is evaluated using this metric and previous dose distribution metrics. The use of the weighting method generally improves print quality metrics when printing around inserts and increases in-part voxels’ doses compared to out-of-part voxels. Where elimination of error is possible, this method can reduce the number of optimisation iterations required to eliminate error.