640t – Installation and Operating Instructions
Film Alignment and Tension
Film Alignment
The top and bottom supply rolls must be aligned as closely as possible. Misalignment can cause adhesives to stick to the rollers.
Measure here
Fig. 6-18. Measuring Points on a Typical Laminator..
To align the supply rolls:
1.Use a ruler to measure the distance between the left edge of the roll to the side frame.
2.Measure the distance between the right side of the roll to the side frame.
3.Shift the roll side to side to ensure that the two measurements are equal.
Film Tension
Proper film tension, known as brake tension, is the minimum amount required to eliminate wrinkles in the finished item. As the film roll becomes smaller, tension increases, thus the adjustment needs
to be loosened. Film tension should be checked occasionally to ensure that the adjustment is correct.
The film should be taut with no gaps between the film and pressure rollers. A properly adjusted roll of film should not require excessive force to turn by hand. Film tension should be enough to introduce a minor amount of drag as the film unrolls. Insufficient tension causes wrinkles, while too much tension causes stretching (necking). Uneven tension between the top and bottom rolls create curl. Too much upper tension creates upward curl. Too much lower tension bottom causes downward curl.
Fig. 6-19. Tension Adjustment Knobs and Motor.
The machine is equipped with external tension knobs located on the left side. Turning the knobs clockwise increases the tension while counterclockwise decreases the tension.
Refer to “Tension Controls” on page
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