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4-2 Adhesives

4-2.1 General

Adhesives include glue, paste, cement, mucilage, cold emulsion, and thermal plastic. An adhesive used to close a container is adequate if, when the container is opened, at least a 50-percent fiber tear occurs on the surface to which the adhesive is applied. An adhesive used on tapes or box flaps must remain serviceable in temperatures from -20° to 160° Fahrenheit.

4-2.2 Box Flaps

For box flaps, the adhesive should cover at least 50 percent of the box flaps and be applied no more than 1/4 inch from the box flap ends.

Alternatively, four strips of hot-melt adhesive may be used on each part of the box flap where the outer flap lies over the inner flap, but only if the strips have the following characteristics:

• Are 3/16 inch wide each (after compression).

• Are no more than 1-1/2 inches apart (with the first strip no more than 1/2 inch from the center seam).

• Extend to the full width of the inner flap (unless hot-melt adhesive is applied to 25 percent of the area where the outer flap lies over the inner flap).