Cast Urethane Parts

Cast Urethane Parts are excellent for  low-volume manufacturing, marketing samples, pre-production runs, and test prototypes.  A great feature of Cast Urethane parts is the ability to over-mold a different material to an existing part. 

The Cast Urethane Process

First SLA rapid prototype master pattern is made. A Machined and/or fabricated master patterns can also be used for tighter tolerances. The model is inspected for accuracy then the “appearance” surfaces are bead blasted, sanded smooth, and a primer coat is applied to achieve the surface finish required to meet your application requirements. If the parts are to be polished or cast in clear resin then the surface will be polished to a gloss finish in preparation for making the silicone rubber mold.

Next the mold is created. The silicone rubber uses a room temperature vulcanization process typically referred to as RTV. The part is carefully scrutinized by one of our technicians to determine the best molding setup to achieve the highest quality urethane casting reproduction. Parting lines are selected to assure best location thus avoiding flash on appearance surfaces. Rubber mold runners, gates, sprues and vents are located in areas to optimize mold fill, isolate and minimize air bubbles to non-critical areas, and optimize appearance surface quality.

The SLA rapid prototype master is set-up on a parting block to make a two (or many) part mold or suspended in a frame to make a one-part cut mold. Silicone is poured around the SLA master pattern to create the mold. After the silicone is fully cured after about 1 day, the master pattern is removed and the mold is reassembled, whereupon the  material is poured into the mold to create the cast urethane part.