1,064,612. Making envelopes. R. WINKLER and K. DœNNEBIER. Aug. 13, 1965 [Aug. 20, 1964], No. 34682/65. Heading B5D. The side 21, 22, bottom 6 and closure 7 flaps, Fig. 1, of an envelope blank are made by trimming marginal portions 8 from a blank 3 cut from a moving web 1, the speed of the blanks being greater than that of the web in order to produce a separation D between the blanks. Fold lines 10, 15 are then made and adhesive applied at 26 and 30 to a side 22 and bottom 6 flaps, before the blank is folded into an envelope. In one embodiment, the direction of motion of the blanks, relative to the blanks, is changed through 90 degrees, after the transverse score lines 10 have been made, and before the score lines 15 are made, so that these latter score lines are also made transversely. Alternatively, the blanks themselves may be rotated through 90 degrees, at station (11SP1/SP), Fig. 4 (not shown). One or more windows 17, cut in the blank at station 16 by a suitable rotary cutter, are then covered by a transparent foil 19 at station 18. After glue stripes 30, 31 have been applied to the bottom and closure flaps, and the bottom flap has been folded down (stations 28, 29), the blank passes through a drying zone T. The closure flap 7, is then closed and the envelopes stacked. A self-sealing envelope may be produced, Fig. 2 (not shown), by applying latex based stripes (34, 35) on the closure flap (7a) and at a corresponding position (35) on the envelope body. The bottom flap is closed by applying a stripe (39SP1/SP) of dextrin or other suitable gum. The envelope then passes through a drying zone (TSP1/SP) and is stacked with its closure flap open. To produce an envelope with a bottom closure such that it can be opened and reclosed, stripes (36, 37), Fig. 3 (not shown), of suitable adhesive are made on the bottom flap (6b) and in a corresponding position on the envelope body. The open-ended blank is then passed through the drying zone (TSP11/SP) after which the bottom and closure flaps are closed, the bottom flap (6b) adhering to the envelope body.
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