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.
Patents. A contaminated article is subjected to vapor degreasing operations wherein the vapor degreasing solvent comprises a blend consisting essentially of perchlorethylene and trichlorethylene, wherein in the preferred embodiment, the perchlorethylene comprises about 81 volume percent of the degreasing solvent,...he solvent blend extends the normal life of perchlorethylene degreasing solvents alone, or in combination with stabilizers and the like, or, alternatively, allows the utilization of trichlorethylene at temperatures higher than those that would normally cause pyrolysis.