Warping - Mass Loss

mass loss warping parts curling or bowing during secondary curing mass loss warping how to identify mass loss warping can be diagnosed as follows thin walled parts curling edges bowing ends parts with varying thickness misshapen, bowing edges mass loss warping is the most common type of warping, and is typically the reason for warping reference also warping print stress docid\ npu8fpie0xcq7t9gms0hr and warping solvent docid 0nvo8yolxreg1jpql0rra for less common types of warping that can occur under very specific circumstances cause differing wall thicknesses solution print preparation or part design cause differing wall thicknesses solution print preparation or part design cause differing wall thicknesses solution print preparation or part design cause inconclusive troubleshooting it is recommended that you review all the possible solutions before taking action to ensure you are pursuing the best course of action if the best course of action is not apparent, try the troubleshooting options in the order listed refer part defects for more tips process, material, and hardware checks if any of these conditions apply to your print, take the corrective action and reprint to see if the problem is resolved drying ensure parts have been fully dried after washing with solvent wait at least 3 5 minutes at a bare minimum, even if you can't see any surface wetness try drying parts longer up to the resin's cure start time reference materials overview baking adjust baking method to apply even heat around the part bake flat surfaces on a raised mesh hang parts and/or use a baking fixture to hold parts in place during the bake pack parts in salt fnote only select resins are compatible with salt packing reference materials overview or more information reference thermal curing docid 7ne6rgdaszpapohh5qozm for more information baking print preparation or part design adjustments the following solutions will address print or part related causes of the defects choose among the suggested actions below and select the best approach for your application usually only one type of adjustment is needed design redesign part thicken walls of your part to reduce mass loss reference dls design guidelines for guidelines per resin the example on the upper left is printed at 1 0 mm thick, below the recommended unsupported thickness for rpu 70 resin loss of mass, relative to surface area is high, and the loss of mass occurs randomly throughout the part leading to the curling you see here the version on the lower left is 2 5 mm thick, the recommendation for rpu 70, which is correctly flat match wall thicknesses to mitigate differential shrinkage or if unable, make changes in thickness as similar and gradual as possible the example on the upper right has a thin walled honeycomb pattern in the center and a thicker frame around the exterior the thin honeycomb loses mass more quickly than the thicker frame, which pulls in the edges to produce the bowing you see here the version on the lower right adjusts the frame to be thinner, more closely matching the honeycomb dimensions, which keeps the edges straight design if problems persist, please reach out to carbon support explanation & causes explanation warping is the manifestation of mass loss, which is a form of shrinkage mass loss is a natural and expected side effect of the thermal curing process, but it leads to warping when that mass loss occurs unevenly uneven mass loss can occur for a few reasons parts not fully dry after solvent washing uneven exposure to heat thin walls differing wall thicknesses reference dls printer dynamics for more information about shrinkage in dls production causes post processing how the part is handled in post processing is causing the defect post processing root issue problem why defect presents drying wet parts parts must be fully dried after washing per protocol if solvent has not completely evaporated from the part prior to baking, mass loss could be uneven secondary thermal curing (baking) uneven exposure to heat monomers escaping the part will take the easiest path when some surfaces become hot more quickly than others, such as surfaces sitting directly on the baking tray, the molecular structure will change more quickly making it harder for monomers to escape therefore monomers will take the easier path out of surfaces that are still getting hotter, such as those openly exposed print preparation or part design how the part is oriented , supported , or designed is causing the defect print preparation or part design cause root issue problem why defect presents design thin walls thin walls have more surface areas exposed for unlinked monomers to escape design differing wall thicknesses thinner walls will lose more monomers than thicker ones, which can distort the intended shape of the part