Expanded foam Process

Hi Core77,

im developing an insulated body which is insulated by a rigid PU foam cavity. The problem is, I would like to use the foam’s rough finish as an aesthetic component. The foam we use ends up some shade of yellow. does anyone know how to vary the color when expanding the foam? or is the only option to paint it.

Alternatively if you know of any pre colored liquid foam products that would be handy. Ive seen PU foam in all colors so I don’t see why this should be a problem, im guessing if one add some sort of coloring agent in the mixing process one can achieve this effect?


Check the Smooth-On site. I got tons of stuff from there in school.

One of the base components in the PU mixture can be pigmented in some form or a third pigment loaded stream added to the AB mixture. The usual color is black for a lot of components. I visited a factory making ATM facades years ago, and have assumed since that all were made with RIM PU foam, colored material surface finish, gray. PU solid material is easily colored, the foamed stuff should be similar. The issue will be with consistency however, the swirling of the foam and the size of the part can have changes in density, and that may affect the color of the skin.

Some auto body panels have been made from pigmented RIM foam with a class A finish.

You can get pigment for polyurethane casting from Freeman, FMSC - Freeman Color Tints

And you can get 2-part polyurethane foam from Special Effects, http://www.fxsupply.com/poly/poly.html

Although I have never done it, I can’t image why you couldn’t take the pigment from Freeman and add it to the B side (Polyol) of the Special Effects foam kit.