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7. When starting the machine to begin lamination, let at least 10 inches of film go
through the rollers before inserting the items to be laminated. This takes out slack in
the film and removes the cooler strip of film that forms just in front of the nip when
the laminator is hot but film is not being advanced. This also removes any areas of
film with excess adhesive that may have pooled just beneath the shoes.
Examine the film coming out the back of the machine. If bubbles or wrinkles appear
in the film, this means there is not enough tension to draw the film tight and smooth
over the heat shoes. Turn the tension control knobs clockwise to increase the
tension.
If the film is stretching and gets narrower as it goes across the shoes, supply roll
tension is too high, and the temperature setting may also be too high for that film.
Film that is 1.5 mils thick requires very little tension.
REMEMBER TO TURN BOTH THE TOP AND BOTTOM TENSION CONTROL
KNOBS THE SAME AMOUNT TO KEEP TENSION THE SAME ON TOP AND
BOTTOM ROLLS. If the film curls up or down after it leaves the machine, read the
above section on supply roll tension again and readjust the supply roll tension on
both rolls.
If the tension appears balanced but you notice waves or ripples toward the center of
the web of film as it comes out the back, the temperature may be too high or the
lamination speed may be too high for that film. This type of wave in the film is called
a "heat wrinkle." Heat wrinkles are formed when the film has not cooled enough
before coming out the back of the machine. For the best results, the film should be
cooled below melt temperature while it is pulled tight and perfectly flat between the
laminating rollers and the pull rollers. If it gets out the back of the machine while still
at or above melt temperature, heat wrinkles can form. The major reason for fans
on a laminator is to cool the film, not to cool the machine.
8. Another reason the film needs to cooled is so it can be trimmed cleanly by the
slitters. If the film is too hot when the slitters are in use, the trimmed edge will be
messy because of liquid adhesive hardening on the trimmed edges of the web.
Adhesive will also build up on the knives and prevent them from trimming neatly.
To align the slitters blades to a particular job, start by positioning one or both guides
to feed the work at the center of the web. Most operators find that they can get the
most accurate sheet alignment by using only the left feed guide. Feed a test sheet
from the job into the laminator and stop it when it is between the rollers.
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