Patent ID: 7455804

Claim:
A process for forming a three-dimensional article in sequential cross-sectional layers in accordance with a model of the article, the process comprising the steps of: defining a layer of powder material; applying a liquid reagent to the powder layer in a pattern corresponding to a respective cross-sectional layer of the model; and repeating these steps to form successive layers; wherein the powder comprises a first reactive component selected from an organic or organometallic polymer, oligomer or monomer and the liquid reagent includes a second active component comprising an oxetane, the second active component causing a polymerization reaction to take place in said layer by chemically reacting with said first reactive component within the powder to form a new chemical component, and thereby to form substantially void-free regions in the article where the liquid reagent has been applied to the powder material and wherein the article which is formed has a tensile strength of greater than about 25 MPa.