Silicone 40A Resin is a pure silicone without added monomer or acrylate, which combines the material properties of cast silicone with the benefits of 3D printing. Printing with Silicone 40A Resin eliminates the need for tooling and labor-intensive casting processes, enabling you to produce custom silicone parts with isotropic properties and complex geometries that aren’t possible with casting or molding.

Silicone 40A Resin is a cost and time-effective solution for fabricating functional prototypes, validation units, tooling, and small batches of silicone parts. This wide range of applications means that you may need to use a variety of techniques when printing with Silicone 40A Resin. As you become more proficient, consider adding these advanced techniques to your workflow.

When you generate supports with the Auto-Generate All or One-Click Print features in PreForm, PreForm often adds supports to vertical or steep surfaces to ensure that your models are fully and robustly supported. If your models have thick walls, internal trussing, or otherwise solid geometric support (e.g., a cylinder), many of these touchpoints can be removed without causing a print failure. Use PreForm’s manual support editing options to remove touchpoints from a model.

Internal supports are any supports with both ends touching the model, instead of one end connecting to the raft. They can be useful when securing overhangs and other hard-to-reach minima, but are hard to remove and can disrupt the intended functionality of your printed parts. If internal supports are making your printed parts difficult to post-process or use, reorient your models in PreForm to reduce or eliminate the need for internal supports.

If your models cannot be oriented to avoid internal supports, consider disabling internal supports when automatically generating supports or adding supports manually. If you’ve already placed support touchpoints, use PreForm’s manual support editing options to remove touchpoints from a model.

Orienting and supporting a model often comes with tradeoffs. A common example is between cups and overhangs. "Cups" refer to hollow volumes or cavities in a model. Air becomes trapped between the part and the resin tank as the build platform lowers, and the resulting suction applies forces to the part. An overhang is any part of a model that extends outward and is not supported by the previously-printed layers. If your model has cups, tilting the model to eliminate the suction effect often leads to more overhanging features.

Normally, best practice would be to orient the model to avoid cupping and add touchpoints to fully support the resulting overhang. However, for Silicone 40A Resin, this recommendation is reversed: orient your models with cupping rather than causing overhangs farther away from the build platform. Silicone 40A Resin is able to handle cupping well due to its high tear strength and elongation at break but overhangs can shift while printing, leading to delamination.