Patent attributes
The invention provides a roll assembly including a pair of cylindrical rolls that are positioned in an opposing cooperating relation for receiving a sheet material therebetween. A plurality of projections on at least one of the rolls extending radially outward from a surface thereof and a plurality of corresponding recesses is provided on the other roll. The projections and corresponding recesses are positioned and arranged on the rolls for contacting and engaging a sheet passing between the pair of rolls. The projections each include an outermost surface portion that is positioned for contacting a discrete portion of the sheet and for entering a corresponding recess on the opposite roll. When rolls rotate about their axes, the projections engage the discrete portion of the sheet material which results in the discrete portion entering the recesses with the projections so as to stretch the sheet in multiple directions.
