Better Packages Section 3
Sealing with Gummed Tape
22
PROPER TAPE MOISTENING:
Dispense a piece of tape and examine the adhesive surface. The tape should:
• Be evenly wet
• Have no dry spots
• Have no spots where water is running off the surface.
Rub the wet adhesive with your finger.
• The adhesive should have an “oily” feel and consistency.
• You should be able to move the adhesive underneath your finger.
When you rub two wet adhesive surfaces of the tape together against each other, you should see
“strings” of adhesive stretching between the two surfaces as you pull them apart, looking much like taffy
as it is pulled.
If the tape is too wet or watery, it:
• Will not set fast enough
• May slip slightly over the surface of the carton, causing a “loose” seal
If the tape is not wet enough, it:
• May be tacky or sticky like pressure sensitive tape, but not “oily” like properly
moistened tape.
• Is too dry to properly activate the adhesive which will prevent a permanent bond from forming (because
the adhesive cannot penetrate the corrugate fibers).
• May too easily pull off the carton during handling and transportation.
ADJUSTING THE AMOUNT OF WATER APPLIED TO THE TAPE:
• Adjust the height of the water bottle:
- Higher to apply more water
- Lower to apply less water
• Never use any dispenser for water-activated tape without a water bottle.
• Do not add water to the water bottle “whenever it looks low”. This will always:
- Cause overwetting when the tank is first filled
- Cause underwetting when it needs to be refilled
SETTING HEATER CONTROLS:
In most situations, the application of heat is helpful for reactivation of the adhesive. Different tape
manufacturers use different adhesive formulas. Some require more or less heat than others.
You should experiment with different heat settings to optimize adhesive performance for the tape you are
using and the conditions under which you are operating. Carton sealing done in a cold meat packing plant
will certainly require a higher temperature setting than will carton sealing done in a tropical plant nursery.
As a general rule, the strength of the adhesive bond will increase as the temperature setting of the heater is
increased up to some optimum point. Too much heat:
• May cause the tape to dry too quickly before the glue has properly set.
• Can cause the tape to curl and become difficult to work with.
• In extreme cases, can cause delamination of the tape, causing the tape to fail.
See Section 2, “Adjusting the Setting on the Heater Assembly”.
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