Conveyor systems and methods

A conveyor system comprising a tilted conveyor belt having an outer conveying surface extending in width from an elevated side edge to a lower side edge and advancing downstream in a direction of belt travel parallel to the elevated and lower side edges, wherein the outer conveying surface is tilted at a tilt angle off horizontal sufficient for non-flat packages, but not flat packages, received on the outer conveying surface to move downward across the width of the tilted conveyor belt and over the lower side edge and wherein the tilted conveyor belt further comprises retention means to prevent flat packages, but not non-flat packages, on the outer conveying surface from sliding on their bottoms across the width of the outer conveying surface of the tilted conveyor belt and over the lower side edge so that the flat packages on the outer conveying surface exit the conveyor belt downstream of the non-flat packages;

• wherein the retention means comprises a high-friction surface forming the outer conveying surface of the titled conveyor belt and presenting enough friction to the bottoms of flat packages to prevent them from sliding over the lower side edge of the titled conveyor belt or wherein the retention means comprises a raised barrier extending along the length of the outer conveying surface to a height sufficient to prevent flat packages from sliding over the lower side edge of the titled conveyor belt.