Slit-sheet-paper expansion systems and methods using friction brush(es) and/or other friction member(s)

An expansion system for expanding expandable slit sheet paper, comprising:

• a roll of expandable slit sheet paper, said expandable slit sheet paper having an array of slits that expand into open cells upon pulling in a lengthwise direction;
• a friction brush for applying friction along a lateral side of said expandable slit sheet paper;
• said friction brush having a plurality of elongated bristles or fibers, said friction brush having a length configured to extend across a width of said roll of expandable slit sheet paper;
• a planar surface opposing said friction brush such that distal ends of said elongated bristles or fibers contact a first side of the expandable slit sheet paper unrolled from said roll of expandable slit sheet paper and a second side of the expandable slit sheet paper opposite to said first side of the expandable slit sheet paper contacts and presses against said planar surface due to pressure applied by said friction brush;
• and
• whereby when said expandable slit sheet paper unrolled from said roll of expandable slit sheet paper is pulled between said friction brush and said planar surface, said expandable slit sheet paper is expanded into open cells.