Method of manufacturing risers for shelving units

摘要

A method of fabricating discrete risers for shelving units includes the step of providing a plurality of openable and closable mold segments arranged end to end along a continuous path, and circulating the plurality of mold segments through multiple revolutions of the continuous path such that the mold segments are closed while traveling along a molding section of the continuous path. A molten stream of plastic is continuously extruded at an upstream end of the molding section and into mold cavities of the closed or closing mold segments. A pressure differential is applied to the mold cavities of the closed mold segments to conform the molten stream of plastic to the mold cavities. A continuous train of interconnected risers is ejected at a downstream end of the molding section. Discrete risers are separated from the continuous train.