Compression package wrapping apparatus and method

Abstract

A package wrapping apparatus and method compresses a package of napkins or a similarly soft bulked product during the wrapping operation to provide a tight wrapped package which does not become loose with settling. An air activated expandable elevator plate allows the bottom of the napkin package to be completely supported during the wrapping operation, and contracts to allow the plate to be lowered between front and rear underfolders. This allows the napkin stack to undergo a greater degree of compression without defects, since folding or curling of the napkin edges over the elevator plate is avoided. An air activated movable top compression plate applies variable downloading against the top of the package. As the elevator plate is raised, the package presses against the top compression plate and is thereby compressed. The top compression plate is then withdrawn to a position corresponding to the desired finished package height, and a sliding transfer operation of the package to a heat seal device is performed. This transfer operation is completed before the compressed package has recovered to the desired package height. In this manner, downward pressure on the package during the transfer operation is greatly reduced. As a result, the napkins and the wrap are much less likely to be displaced from their proper positions prior to the heat seal, and occurrences of defective packages are reduced. The air activated expandable elevator plate and top compression plate assemblies of the invention are simple in construction and may be readily retrofitted to existing wrapping machines.