Rapid Prototyping involved creating a working model of various parts of the system at a very early stage, after a relatively short investigation. The method used in building it is usually quite informal, the most important factor being the speed with which the model is provided.
There are water-and solvent-based -- also called oil-based -- polyurethane varnishes. Water-based polyurethanes are more environmentally friendly and safer to use than solvent-based, but they are not as resistant to wear and tear as solvent-based products.
Some slow coalescents (e.g., Texanol) will remain in acrylic coating films for many weeks or longer. Acrylic/urethane polymers based on DESIGNED DIFFUSION Resin Technology provide a novel mechanism for the faster release of volatile materials, such as coalescents and co-solvents, from the drying film.ome slow coalescents (e.g., Texanol) will remain in acrylic coating films for many weeks or longer. Acrylic/urethane polymers based on DESIGNED DIFFUSION Resin Technology provide a novel mechanism for the faster release of volatile materials, such as coalescents and co-solvents, from the drying film.