公开(公告)号：US3636918A

公开(公告)日：1972-01-25

申请号：US87919369

申请日：1969-11-24

Applicant: PACKAGING CORP AMERICA

Inventor： FISCHER JOHN P ,  KAHLER VERN R

IPC: B26F1/24 ,  B31F1/28 ,  B05C11/12

CPC classification number: B31F1/2822 ,  B26F1/24

Abstract: A method and apparatus are provided for treating one surface of a double-faced corrugated unit, such as fiberboard, so as to render the latter more responsive to vacuum pressures when said unit is as a substrate in combination with a heat-softened film during formation of a skin-pack-type package. In utilizing the instant method only one surface of the unit is perforated and then coated with a suitable material whereby the heat-softened film can be readily responsive to the vacuum pressures exerted on the unit and at the same time become securely bonded to the substrate. The perforating and coating steps are accomplished expeditiously during one pass of the unit through the apparatus.