Film alignment and tension, Film alignment, Film tension – GBC 44DT User Manual

Page 31: Testing the web, 44dt, Operating instructions

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Page 6-15

Operating Instructions

44DT

F

ILM

A

LIGNMENT

AND

T

ENSION

F

ILM

A

LIGNMENT

The top and bottom supply rolls must be aligned
as closely as possible. Misalignment can cause
adhesives to be deposited on the rollers.

To align the supply rolls:

Use a ruler to measure the distance between the
left edge of the roll to the side frame.

Measure the distance between the right side of
the roll to the side frame.

Shift the roll side to side to ensue that the two
measurements are equal.

F

ILM

T

ENSION

Proper film tension, known as brake tension, is the
minimum amount required to eliminate wrinkles in the
finished item. Tension adjustments are not necessary
if you are using 1.5 or 3 mil (38 or 75 mic) film unless
the lamination is curling up or down. Generally, 5 and
10 mil (125 and 250 mic) films require more tension.
As the film roll becomes smaller, tension increases,
thus the adjustment needs to be loosened. Film
tension should be checked occasionally to assure
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.

1.

2.

3.

Fig. 6-29. Tension Adjustment Knobs.

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.

Testing the Web

After webbing the machine, it is important that the
films run straight and evenly.

To test the web:

Set the roller pressure handle to an appropriate
position.

Press the

RUN button and run approximately

6 in. (10 cm) of laminate.

Press the

STOP button.

Visually inspect the top and bottom films where
they enter the nip. The films should be tight
against the rollers at both ends. If they are not,
use the tension adjustment knobs to tighten the
loose supply film brake and run another test.

Ensure that the release liner take-up is keeping
the liner tight against the idler bar. If it is loose,
use the tension adjustment knob to increase the
tension.

RUN test materials before laminating good
materials.

1.

2.

3.

4.

5.

6.

Tension Adjustment

Knobs

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