Abstract: The present invention relates to a method of preparing a polymer for rotational molding, and a polymer prepared by said method. The method of the invention comprises grinding a polymer to produce ground polymer particles of a size suitable for rotational molding, heating the ground polymer to a temperature below its melting point, contacting the ground polymer with a peroxide, which may be mixed with an initiator, at a temperature below the activation temperature of the peroxide, and drying and cooling the ground polymer to a free-flowing powder. The method of the invention produces a polymer particle having a size suitable for rotational molding and which has a peroxide curing agent and, if desired, an initiator absorbed therein.

Abstract: A method of making a carpet underlay is provided wherein the underlay is comprised of a sponge rubber body having a load-carrying surface defined by a plurality of cooperating closed-area coplanar portions which define the major part of the area of a plan view of such body.

Abstract: A carpet underlay and an apparatus for and method of making same is provided wherein the carpet underlay is comprised of a sponge rubber body having a load-carrying surface defined by a plurality of cooperating closed-area coplanar portions which define the major part of the area of a plan view of such body.