| abstract |
A FILM IS STRETCHED LONGITUDINALLY THEN CROSSWARDS. LONGITUDINAL STRETCH IS PROVIDED BETWEEN ROLLERS HAVING DIFFERENT SPEEDS, AT A RATE OF AT LEAST 10,000 MN, AND UNDER A STRETCH RATIO OF 2.7 TO 3.5. AT A TEMPERATURE T1 OF 45 TO 60C AND IN A TIME TE (3.9-0.053 T (E BASE OF LOG.), THE FILM IS TRANSFERRED TO THE TRANSVERSAL STRETCH WHICH, UP TO A STRETCH RATIO OF 1, 4 IS TAKEN UNDER AN ANGLE TH LESS THAN 6. AT THE BEGINNING AA OF THE CROSS-STRETCHING, THE FILM IS THICKER AT THE EDGE THAN AT THE CENTER 9. DURING THIS STRETCHING, THE TEMPERATURE OF THE SIDE CLAMPING CLAMPS IS LESS THAN T1 AND THE TEMPERATURE OF THE FILM IS GRADUALLY RAISED UP TO 70 TO 100 C. AT THE END OF CC, THE STRETCH RATIO IS 3 TO 5, AND THE AVERAGE RATE HAS BEEN FROM 2000 TO 10000 MN. UNIFORMITY OF STRETCHING AND BALANCING OF PROPERTIES IN BOTH DIRECTIONS. |