Method of applying at least one web of insulator material to multiple spring assemblies

A method of applying at least one web of insulator material to a plurality of spring assemblies is provided. Each web of insulator material is unwound from a roll, passed along a roller and applied to multiple spring assemblies which are passed between rollers. Each web of insulator material is folded around outermost coil springs along longitudinal edges of the spring assemblies. Side portions of each web of insulator material are glued, welded or otherwise permanently secured to a middle portion of the web of insulator material.