Bucktown Polymers, a polymer development firm based in Chicago, Ill., is offering a new UV curable resin for 3D printers called ROR (Rinse Out Resin). It remains water soluble after curing.

ROR's intended application is investment casting. Traditionally, a resin or wax model is 3D printed, then a mould is formed around the model. Heat is applied to the mould in a step known as the burnout phase and the model is melted out of the mould, leaving a negative where liquid metal can be poured to create a metal version of the original model. This technique is commonly used in jewelry and precision instrument manufacturing.

The idea behind ROR is that it can eliminate the potential pitfalls of the burnout phase, such as leftover ash and polymer expansion. With ROR, instead of heating the mould to melt the resin, the mould is soaked in hot water, which dissolves the Rinse Out Resin, leaving the negative that would normally have been created during the burnout phase. Converting the burnout phase to a rinsing phase is said to cut 8 to 12 hours from the casting process.

ROR is fast curing, rapid dissolving and zero VOC. Compatible with SLA and DLP printers, it cures under light up to Violet 420nm. The water soluble material can be formulated for use with other additive manufacturing technologies such as inkjet and powder-based systems.

ROR is one of an entire line of resins offered by Bucktown Polymers. Other exotics include resins that are bio-compatible, electrically conductive, thermally conductive, scented, and thermochromic (change color with temperature).