RIM (Reaction in molding) molding is a fast prototyping method which enables the large scale production of pieces of large or medium sizes. To make casts, it is necessary to first create a piece (master model) in stereolithography. The prototype print is thus created in a silicone mold. Polyurethane is injected into the mold at low pressure, using a pistol. Just like with vacuum casting, our prototypists must deburr the resulting products.
ADVANTAGES WITH RIM
Parts made with RIM have an increased resistance to shock and friction.
The pieces have a good surface appearance (close to injected parts).
There is a good polyurethane paints “connection”.
The prototypes are ”good material” (close to plastic injection).
The necessary investment is less than that required for compression or injection.
DISADVANTAGES WITH RIM
The mechanical characteristics (Young module and tensile strength) are weak.
The dimensional stability with temperature is relatively low.
The cost is increased.