Process and apparatus for making heat-sealed articles

An integrated process for making an inflatable heat-sealed article, comprising the steps of:

• (A) extruding a first flat film and a second flat film;
• (B) cooling the first flat film and the second flat film so that the first and second flat films will not fuse to one another upon contact with each other;
• (C) contacting the first flat film with the second flat film;
• and
• (D) heating selected portions of at least one of the first and second flat films to a temperature above a fusion temperature, so that the first and second flat films are heat sealed to one another at a selected area, with the selected area providing a heat seal pattern that provides inflatable chambers between the first flat film and the second flat film, the heating being carried out by bringing the first and second flat films into overlying contact with each other with the first flat film contacting a substantially cylindrical outer surface of a heated sealing roller and with at least the first flat film partially wrapped around the outer surface, the outer surface comprising a first surface portion defining a configuration corresponding to the heat seal pattern and formed of a first material having a first thermal conductivity, and a second surface portion formed of a second material having a second thermal conductivity lower than the first thermal conductivity such that only areas of the films in contact with the first surface portion are heat sealed together, unsealed areas of the films remaining where the first flat film contacts the second surface portion, the first and second surface portions being substantially flush with each other at the outer surface, the second surface portion preventing tenting of the films in the unsealed areas.

An integrated process for making an inflatable heat-sealed article, comprising the steps of:

• (A) extruding a tubular film having an outside surface and an inside surface;
• (B) cooling the tubular film to a temperature low enough that the inside surface of the tubular film is cool enough not to adhere to itself;
• (C) placing the tubular film into a lay-flat configuration having a first lay-flat side and a second lay-flat side, so that a first inside lay-flat surface of the first lay-flat side of the tubular film is in contact with a second inside lay-flat surface of the second lay-flat side of the tubular film;
• and
• (D) heat sealing selected portions of the first lay-flat side of the tubular film to the second lay-flat side of the tubular film, the heat sealing being carried out to provide a pattern of sealed and unsealed areas with the unsealed areas providing inflatable chambers between the first lay-flat side of the tubular film and the second lay-flat side of the tubular film, the heat sealing comprising contacting the tubular film with a heated sealing roller having a substantially cylindrical outer surface, the outer surface comprising a first surface portion defining a configuration corresponding to the heat seal pattern and formed of a first material having a first thermal conductivity and a second surface portion formed of a second material having a second thermal conductivity lower than the first thermal conductivity such that only areas of the first and second lay-flat sides of the tubular film in contact with the first surface portion are heat sealed together, unsealed areas of the lay-flat sides of the tubular film remaining where the lay-flat sides contact the second surface portion, the first and second surface portions being substantially flush with each other at the outer surface, the second surface portion preventing tenting of the lay-flat sides of the tubular film in the unsealed areas.