Patent ID: 8162529
Filing Date: 2012-04-24
Classification: B28C

Abstract:
1. A rotary concrete mixing drum comprising: a first helical wall element having a first ramp formation and a second helical wall element having a second ramp formation, the second helical wall element joined to the first helical wall element along a helical seam with the first and second ramp formations disposed adjacent to the seam, the first helical wall element and the second helical wall element forming a substantially continuous common wall having an interior surface circumferentially extending about a longitudinal axis to form an interior of the drum; the interior surface at least partially provided by a polymer infused with a slip agent; wherein the polymer includes polyurethane, and the slip agent is a polytetraflourethylene powder configured to be held firmly in place so as not to substantially migrate within the polymer and having a weight percentage of at least 2% and no greater than 5% of the infused polymer along the surface, or a polyalpha olefin fluid having a branched structure configured so as not to significantly migrate within the polymer and having a weight percentage of at least 2% and no greater than 5% of the infused polymer along the surface.