Лако-красочные материалы — производство

In unsewn binding, adhesives are needed not only for the bonding ofthe back, but also for gluing the side of the cover to fix it on the first page (side glues). To this end, either dispersion adhesives or hot melts can be employed. Dispersion adhesives used for side gluing are commonly based on plasticized polyvinyl acetate homopolymers or EVA copolymers. Hot melts are especially suitable for heavy covers and are based on EVA copolymers or synthetic thermoplastic rubbers mixed with resins and oils.

The adhesives are applied via rollers or nozzles to the book block (Figure 8.42).

These products have a very high hot ‘tack’ — that is, a high initial adhesion which ensures a safe pick-up and bonding of heavy covers. As graphical products are increasingly sophistically designed, conventional adhesive systems are causing more and more problems in side gluing and pasting of endpapers due to weak bonding, oil migration, and so on. Reactive polyurethane hot melts are better suited here and provide safer results. Contacting or noncontacting application to the book block or cover is possible via slot die or round nozzle.