I familiar with making polyurethane parts by pouring into a simple cavity and then curing in an oven.
My question is. Is it possible to injection mold PU parts? Is generally cheaper than injection molded plastic parts?
Thanks
Jeremy
injecion mold PU yes. Cheaper no.
Reaction injection mold exclusively uses PU and is alot less expensive.
I’d like to qualify pier’s answer by saying that PU can be used in lower cost, low volume applications. Reaction Injection Molding (RIM) uses PU and be molded in lower cost molds than what would be required in traditional injection molding because of the lower pressures and less cooling required. Having said that, polyurethanes are a tricky family of materials to use and it really depends on what you need out of the material.
RIM PU can be used for prototypes, but that’s more commony referred to casting although there is some blurring of the lines there. RIM has a more production connotation than castings…
Anyway, PU is often chosen for its material properties and fiinishing methods, but it’s rarely a good one-to-one replacement for traditional thermoplastics. Check out the Bayer Polyuretahnes web site for more information.