Bulk enhanced paperboard and shaped products made therefrom
First Claim
1. A cellulosic multi-ply paperboard comprising:
- (a) predominantly 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./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 coating 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 inch respectively;
(A) a GM Taber stiffness of at least about 0.00716 w2.63 grams-centimeter/fiber mat density1.63 pounds per 3000 square foot ream at a fiberboard thickness of 0.001 inch; and
(B) at a fiber mat density of about 3 to 9 pounds per 3000 square foot ream at a fiberboard thickness of 0.001 inch, a GM tensile stiffness of at least 1890+24.2 w pounds per inch.
4 Assignments
0 Petitions
Accused Products
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./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 inch respectively, has a GM Taber stiffness of at least about 0.00716 w2.63 grams-centimeter/fiber mat density1.63 pounds per 3000 square foot ream at a fiberboard thickness of 0.001 inch, and a GM tensile stiffness of at least about 1890+24.2 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.
-
Citations
69 Claims
-
1. A cellulosic multi-ply paperboard comprising:
-
(a) predominantly 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./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 coating 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 inch respectively;
(A) a GM Taber stiffness of at least about 0.00716 w2.63 grams-centimeter/fiber mat density1.63 pounds per 3000 square foot ream at a fiberboard thickness of 0.001 inch; and
(B) at a fiber mat density of about 3 to 9 pounds per 3000 square foot ream at a fiberboard thickness of 0.001 inch, a GM tensile stiffness of at least 1890+24.2 w pounds per inch. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69)
-
Specification