Rotational molding materials & finishes

I’ve been working on a furniture project lately, and, because things like low production volume, durability and ease of production/assembly are high up on my list of design considerations, I’ve been looking at rotomolding as an option. While these are by no means high end pieces they can’t feel cheap or childish, and my head instantly goes toward things like my old Little Tikes Cozy Coupe: fine for an outdoor toy, but a little less refined than what I’m trying to achieve. Is there the option for something similar to what you would get from an in-mold film on an injected part? What else has anyone had success with? Thanks for the help.


Is there also the possibility of something that is more foam-like than hard plastic? I’m also considering compression-molded EVA or something similar.

Try RIM, reaction injection molding. It injects a urethane foam. Painting is usually the final finish. Low runs. Tools are typically aluminum but since the injection pressure is so low, they can be made of Ren-Shape.

Thanks, iab

This material been around for a while. Nyrim, a nylon infused RIM material, great characteristic. AP-NYLON® Additives - L. Brüggemann GmbH & Co. KG

Rotocasting might fit the bill. I have never found any in mold decorations for these processes as the pressure is so low and the surfaces generally quite curved.

Pretty sure this is rotomolded PU foam, although it may be a subset of rotomolding. I made one in a tangential manufacturing survey class. Don’t know how those guys scored the old mold to the original nerf turbo football! Must have been because they were so awesome, they needed a new mold b/c the old one wore out…

We’ve used molded-in graphics on rotomolded parts. Due to the size of some of these pieces, rotomolding is really the only option outside fabricating the whole thing. Sometimes graphics are applied by printing onto a film which is placed in the mold cavity and then the plastic is melted around it. We’re not talking full coverage though, more like a decal.

Tools are typically aluminum but since the injection pressure is so low, they can be made of Ren-Shape.

No Way!!! I didn’t know that! Wouldn’t have guessed it could handle the psi/temp range.

… now you say, “Way!” :wink:

Thanks iab, that might come in handy, of I ever get my sideproject off the ground!