Лако-красочные материалы — производство

Low-test animal glues, both bone and hide, were used extensively in gummed tape man­ufacture. Animal glues have been displaced to a considerable extent by dextrins and starches. They are still used as an additive to dextrins and starches to improve adhesive properties, and also alone or with dextrins for specialty paper or cloth tapes. Animal glues possess a high, aggressive tack, good open time and set properties, permanent bond, and excellent machinability. Properties are frequently modified as to tack, open time, set, and wettability by the addition of modifiers such as wetting agents, plasticizers, and gel depres­sants, in addition to dextrins.

The gumming adhesive is generally prepared at 50% concentration and applied at a dry adhesive deposit of about 25% on the basis weight of the paper or cloth backing. The adhesive is applied to the backing by roller applicator at 140 to l45°F and either passed over drying rolls or through a tunnel dryer. It is stored in rolls for subsequent slitting, printing, and cutting into standard rolls for use.