Formation of laminated packaging blanks

• US 3,987,711 A
• Filed: 04/09/1975
• Issued: 10/26/1976
• Est. Priority Date: 04/10/1972
• Status: Expired due to Term

• Current Assignee: Thiele Engineering Company
• Original Assignee: Paxall, Inc.
• Inventors: Silver, Stanley Milton
• Primary Examiner(s): Coan, James F.
• Application Number:
  US05/566,417
• Time in Patent Office: 566 Days
• Field of Search: 93/36.01, 93/36 R, 93/36.6, 93/36 M, 229/14 BA, 229/14 BL, 229/14 B, 229/14 R, 156/252, 156/324
• US Class Current: 493/110
• CPC Class Codes: B65D 5/563 Laminated linings; Coatings
• CPC Class Codes: Y10T 156/1056 Perforating lamina

Abstract

Laminated blanks for forming moisture-resistant packages are produced from a substrate, such as cardboard. A continuous web of substrate is perforated and fold lines formed. Perforated regions are stripped therefrom prior to laminating with moisture-resistant heat-sealable sheeting using a heat-weakenable laminating material. Thereafter, a multitude of rows of individual blanks are profiled by die-cutting the laminated web. The blanks have unsupported sheeting regions disposed along an edge portion of the substrate which provide membranes or webs that are adapted for sealing to another portion of the laminated sheeting to form a continuous barrier that may be used to prevent wicking in an erected package.

Claims

1. A method for forming and sealing a moisture-resistant package using a foldable blank made of a fibrous material substrate laminated by a heat-weakenable laminant to moisture-resistant sheeting, the blank having at least one unsupported sheeting portion along at least one free edge of said blank, wherein the method includes the steps of folding said blank so that said unsupported portion lies adjacent another region of said sheeting, applying heat and pressure directly to said unsupported portion while it is in contact with said other sheeting region to seal it thereto while simultaneously melting the laminant by which said other sheeting region is adhered to said substrate and detaching same therefrom, and folding and sealing said detached substrate to complete the formation of a part of the package.

2. A method in accordance with claim 1 wherein said package is generally tubular in form and said unsupported portion forms part of an end closure of the package.

3. A method in accordance with claim 2 wherein said sheeting portion is disposed interiorly of said substrate and wherein said detached substrate is joined by adhesive to another region of said substrate to complete the end closure.

4. A method of forming blanks, each of which comprises a unitary substrate adhered by weakenable laminating material to an essentially overall layer of heat-sealable material, and each of which may be folded to adapt it for use in the forming and sealing of moisture-resistant packaging, wherein the improvement comprises

providing a continuous web of fibrous material substrate having a longitudinal grain direction and having sufficient width to provide parallel longitudinal rows of blanks,

removing selected areas of said web to provide openings which register with at least one sealing region in respect to each individual blank and imparting fold lines to said substrate web to define at least four serially connected body panels plus end closure means,

thereafter using a heat-weakenable laminating material having a melting temperature between about 140°

and about 190°

F. to laminate a continuous web of a moisture-resistant sheeting over one surface of said substrate web including said openings, said sheeting being heat-sealable at a temperature above the melting temperature of said laminating material,

thereafter profiling individual blanks to separate them from adjacent blanks in the same row and in adjacent rows by severing the combined substrate-sheeting lamination along paths which cut the sheeting at at least some of said openings, whereby individual blanks are formed each having at least one unsupported sheeting portion at an edge location along the profile thereof, which unsupported sheeting portion constitutes a part of said end closure means,

forming said blank into a tubular configuration with said sheeting disposed interiorly of said substrate,

applying heat directly to said unsupported portion to heat-seal said unsupported portion to the sheeting of another part of said end closure means to form a sealed connection while detaching said other sheeting part from its corresponding substrate part by melting the laminating material at this location, and

completing the end closure by folding and sealing said detached part of said substrate.

5. A method of forming side-seamed carton blanks, each of which blanks comprises a unitary substrate adhered by weakenable laminating material to an essentially overall layer of heat-sealable material and each of which blanks has fold lines imparted thereto to define four serially connected body panels for forming a tubular body plus a side-seaming flap hinged along the side edges of said body panel at one lateral edge of the blank plus end closure means, wherein the improvement comprises

providing a continuous web of fibrous material substrate having a longitudinal grain direction and having sufficient width to provide parallel longitudinal rows of blanks,

removing selected areas of said web to provide openings in respect of each individual blank which register with at least said end closure means and the side edge of said body panel at the opposite lateral edge of said blank,

using a heat-weakenable laminating material having a melting temperature between about 140°

and about 190°

F. to laminate a continuous web of a moisture-resistant sheeting over one surface of said substrate web including said openings, said sheeting being heat-sealable at a temperature above melting temperature of said laminating material,

thereafter profiling individual blanks to separate them from adjacent blanks in the same row and in adjacent rows by severing the combined substrate-sheeting lamination along paths which cut the sheeting at at least some of said openings and both along and across the grain direction of said continuous substrate web,

folding said blank upon itself along said fold lines so that said sheeting is disposed on the exterior surface of said blank in overwrapped configuration, with said side-seaming flap disposed interiorly of said body panel at said opposite lateral edge, and

applying heat directly to said unsupported portion of said body panel while it is in surface contact with said side-seaming flap so as to heat-seal said unsupported sheeting portion to the sheeting portion of said side-seaming flap.

6. The method of claim 5 wherein said side-seaming flap has a lateral width greater than the width of said unsupported portion and wherein prior to said heat-sealing an adhesive is applied so as to create an adhesive bond between the undersurface of said fibrous material substrate and said side-seaming flap along a zone adjacent said unsupported portion.