Two Shot Molding / Over Molding

This process can be difficult to master. Metro Rapid Prototyping has the experienced technicians available for this task and does two-shot molding, or over-molding, on a routine basis. Most combinations of urethane materials can be combined to meet your two shot 3D part needs.

The basic process involves two (2) stereolithography models; one (1) being of the completed assembly and one (1) being of the rigid, or base, portion of the assembly. A silicone, or RTV, mold is created for both models. At this point, the selected urethane material can be injection in the 'base' mold to obtain the rigid, or main, portion of the complete assembly.

Once the 'base' portion is cured, it is placed in the 'assembly' mold. At this point in the 'assembly' mold, the only cavity, or pocket, left is for the second urethane material. It will then be injected with the second material and placed to cure. Typically, the material being used to over-mold the base material is of a softer durometer.