Paperboards having improved bending stiffness and method for making same

摘要

Paperboards having improved MD and CD bending stiffness by including a paperboard binder coalescing agent to cause starch paperboard binder to coat at least some of the paperboard fibers. Also a method for preparing these improved bending stiffness paperboards by combining with an untreated paperboard fiber stream a treated paperboard fiber stream where at least some/at least a portion of the paperboard fibers are coated with a starch paperboard binder due to the coalescing action of a paperboard binder coalescing agent.

主权项

1. An article comprising a ply of paperboard comprising:
paperboard fibers which comprise at least about 50% by weight hardwood fibers; a starch paperboard binder, and a paperboard binder coalescing agent in an amount sufficient to cause the starch paperboard binder to coat at least a portion of the paperboard fibers; the paperboard having:
a caliper of from about 12 to about 18 points;a basis weight in the range of from about 140 to about 200 lbs/3000 ft2;a MD bending stiffness equal to or greater than a first curve defined by the equation:
y1=0.5297x2.2095, wherein x is the caliper of the paperboard and y1 is the MD bending stiffness in Taber Stiffness Units; anda CD bending stiffness equal to or greater than a second curve defined by the equation:
y2=0.2188x2.2681, wherein x is the caliper of the paperboard and y2 is the CD bending stiffness in Taber Stiffness Units.