Method for strengthening the spine region of a file formed from a single blank

摘要

The blank (2) for such files consists of paper, thin card, plastic film or the like and is divided in one piece into a front cover (3), a spine (7) and a rear cover (4) by two folded joints (5 and 6). The spine region comprises the actual spine (7), which is approximately 20 mm wide, the folded joints (5 and 6) and an edge strip of the front/rear cover adjoining each folded joint. During handling, the spine region is greatly stressed by holding and is intended to be reinforced by adhesive strip applications (8). To reinforce the spine (7), the blank (2) is guided with the inner side upwards through a device with two heads (9 and 11) arranged one behind the other. Each head (9 or 11) has a number of nozzles (10) next to one another. Both heads (9 or 11) are offset laterally in relation to one another by the spraying width of a nozzle so that a number of adhesive strips (8) is applied according to the spine width, which then run into one another. In this connection, the adhesive, e.g. glue, liquid plastic or the like, is dried behind the ongoing application by the air of a blower, by infrared rays or the like.