| abstract |
IN APPARATUS FOR EFFECTING MICRO-LENGTH STRETCHING OF WEBS OF MATERIAL TRANSVERSELY OF THE LENGTH OF SAID WEBS COMPRISING AT LEAST ONE PAIR OF CYLINDRICAL ROLLS, EACH OF SAID ROLLS HAVING A SERIES OF CIRCUMFERENTIALLY EXTENDING AXIALLY SPACED GROOVES AND LANDS, MEANS MOUNTING SAID ROLLS IN PARALLEL INTERMESHING RELATION SO THAT THE LANDS OF ONE ROLL EXTENDS INTO THE GROOVES OF THE OTHER ROLL IN SPACED RELATION THERETO, ADJUSTABLE MEANS FOR MOVING THE ROLLS RADIALLY RELATIVE TO ONE ANOTHER TO ESTABLISH THE DESIRED AMOUNT OF EXTENSION OF THE LANDS INTO THE GROOVES OF THE ROLLS, MEANS GRIPPING LONGITUDINALLY EXTENDING SPACED PARALLEL ZONES OF SAID WEB AS THE WEB MOVES BETWEEN THE NIP OF THE ROLLS, AND MEANS FOR ROTATING SAID ROLLS AT A PREDETERMINED ANGULAR RATE IN A DIRECTION TO ADVANCED THE WEB THROUGH THE NIP OF THE ROLLS TO MAINTAIN A MINIMUM TENSION ON THE WEB IN A LONGITUDINAL DIRECTION, THE DISTANCE BETWEEN ADJACENT LANDS OF EACH OF SAID ROLLS BEING NO GREATER THAN 1/10 THE WIDTH OF THE WEB AND SAID LANDS AND GROOVES BEING IN PREDETERMINED INTERMESHING RELATION TO PROVIDE FOR A SUBSTANTIALLY UNIFORM ELONGATION OF THE WEB IN A WIDTHWISE DIRECTION OF AT LEAST 30% OF THE BREAKING ELONGATION OF THE WEB MATERIAL. |