Process and apparatus for manufacturing continuous sealed postal or

Abstract

A process and apparatus for forming a continuous assembly of sealed envelopes having upper and lower sections and comprising at least one insert of the type used as a postal mailer or the like. The process comprises providing continuous upper and lower sheets each comprising transverse weakening lines defining discrete upper and lower sections adapted to be separated along each of the lines, consecutive weakening lines being separated by a substantially constant spacing E1; providing a continuous intermediate sheet comprising transverse weakening lines defining intermediate discrete sheet sections having a width less than the width of the upper and lower sections, consecutive weakening lines being spaced by a substantially constant spacing E2, E2 being less than E1; passing the upper and lower continuous sheets along discrete paths and through drive rollers at the inlet of a sealing station at a velocity V1 equal to the tangential velocity of the drive rollers and passing the continuous intermediate sheet along a path and towards the drive rollers at a velocity velocity V2 less than V1 wherein V2/V1 substantially equals E2/E1. The continuous intermediate sheet is separated to form discrete intermediate sheet sections along each of the weakening lines of the continuous intermediate sheet during passage through a separation station positioned ahead of the drive rollers whereby each of the intermediate sheet sections is positioned between the upper and lower continuous sheets to form the continuous assembly as it enters the drive rollers. The assembly is subsequently sealed.