Method of forming foam moldings having varied density regions

A process for the production of a molding having a mean density of from 0.015 to 0.100 g/cm.sup.3 and having at least two different regions whose densities differ by from 0.005 to 0.030 g/cm.sup.3, the transition zone between the different density regions having a thickness of not more than 25 mm, which process comprises introducing polyolefin foam particles having substantially the same density into individual chambers of a mold divided into at least two chambers by removable dividing walls, said chambers being filled at different pressures or applying different degrees of compression to the particles after the chambers have been filled, thereby providing regions of different density, removing the divided walls, and heating the particles by passing steam or hot air into the mold so that they soften, expand and weld to one another.