US 6,919,111 B2Granted

Coated paperboards and paperboard containers having improved tactile and bulk insulation properties

AssigneeFort James Corporation

InventorsDean P. Swoboda, Anthony J. Swiontek, Timothy P. Hartjes, Kenneth J. Shanton, Erland R. Sandstrom

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Abstract

An improved paperboard has been bulk enhanced by retaining a substantial portion of bulk-enhanced additives including expandable microspheres in a suitable distribution within the paperboard. The cellulosic paperboard web has an overall fiber weight (w) of at least 40 lbs. per 3000 square feet and, at a fiber density of 3, 4.5, 6.5, 7, 8.3, and 9 pounds per 3000 square foot ream at a fiberboard thickness of 0.001 inches, has a GM Taber stiffness of at least about 0.00246 w2.63 grams-centimeter/fiber mat density1.63, and a GM tensile stiffness of at least about 615+13.18 w pounds per inch. The high retention of the bulk enhancing additives is believed to result from the incorporation of suitable retention aids. The resulting paperboard has better GM Taber stiffness values and GM tensile stiffness than prior art paperboards. The paperboard also has increased strain to failure and is able to be formed into suitable paperboard containers without loss of integrity. The resulting containers have increased hold times when they contain hot or cold food or drink.

Claims63

Dependent claims

A cellulosic multi-ply paperboard comprising:

(a) predominately cellulosic fibers;
(b) bulk and porosity enhancing additive interspersed with said cellulosic fibers in a controlled distribution throughout the thickness of said paperboard;
and
(c) size press applied binder coating, optionally including a pigment adjacent both surfaces of the paperboard and penetrating into the board to a controlled extent;
the overall fiber weight “w” of the paperboard being at least about 40 lbs. per 3000 square foot ream
(i) the distribution of the bulk and porosity enhancing additive throughout the thickness of the paperboard, and
(ii) the penetration of the size press applied pigment into the board, both being controlled to simultaneously produce at a fiber mat density of 3, 4.5. 6.5, 7, 8.3, and 9 pounds per 3000 square foot ream at a fiberboard thickness of 0.001 inches;
and
(A) a GM Taber stiffness of at least about 0.00246 w2.63 grams-centimeter/fiber mat density1.63;
and
(B) at a fiber mat density of about 3 to about 9 pounds per 3000 square foot ream and fiberboard thickness of 0.001 inches, a GM tensile strength of at least about 615+13.18 w pounds per inch.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/236,347Filed 6 Sep 2002 · continuation in part
Priority: 26 Feb 1997
Published: US 2003/0152724 A114 Aug 2003
Granted: 19 Jul 2005
Term ends: Not estimatedThe source records don’t support an estimate.

Classification23 codes

B65D 65/42
Packaging materials of special type or form: applications of coated or impregnated materials
B65D 81/3446
For packaging foodstuffs or other articles intended to be cooked or heated within the package: specially adapted to be heated by microwaves
B65D 81/3823
Rigid container being in the form of a box, tray or like container: formed of different materials, e.g. laminated or foam filling between walls
B65D 81/3874
Drinking cups or like containers: formed of different materials, e.g. laminated or foam filling between walls

Family

Application08/806,947Parent of this continuation-in-part · filed 26 Feb 1997
Application09/018,563Parent of this continuation-in-part · filed 4 Feb 1998
US 2003/0152724 A1Pre-grant publication · published 14 Aug 2003
US 2004/0197500 A9Pre-grant publication · published 14 Aug 2003
US 6,740,373 B1Parent of this continuation-in-part
US 6,919,111 B2This patent

From the US filing history. Foreign family members aren’t listed.