Method and apparatus for applying coupon strips to paper bags

A method of applying a coupon strip to the inside of the front panel of a four-sided self-opening paper grocery bag having a front panel, a back panel, inwardly-folded opposite side panels joining the front and back panels, and a bottom panel closing the front, back and side panels, comprising:

• conveying a continuous web of bag paper in the longitudinal direction thereof;
• providing a continuous strip of coupons, the width of the strip being sized to a width less than the spacing between the inwardly-folded side panels of the bag when the bag is folded flat;
• perforating the strip of coupons along a margin thereof, thus defining a margin portion and a detachable coupon portion, the width of the strip being further sized so that at least the detachable coupon portion is not overlapped by the ends of the side panels when the side panels are folded inwardly to form the bottom panel for the bag;
• conveying the continuous strip of coupons longitudinally of the web of bag paper along one side thereof at a position spaced centrally of the longitudinal margins of the web of bag paper;
• applying glue longitudinally solely to the margin portion of the strip of coupons on the side of the strip facing the web of bag paper;
• pressing the margin portion and the coupon portion of the strip of coupons against the web of bag paper to adhere the margin portion to said one side of the web of bag paper prior to forming the web into a tube;
• after adhering the margin portion of the strip of coupons to said one side of the web, continuously turning longitudinal margins of the web of bag paper with the strip of coupons adhered thereto toward said one side of the web to form the web into a tube and enclose the strip of coupons therein;
• periodically cutting a portion of the web transversely to define a top of a first bag and a bottom of a second bag and to cut the strip of coupons into an elongated segment;
• folding portions of the longitudinal margins of the bag inwardly to form inwardly-folded side panels of the bag;
• and
• folding the bottom of the bag to close the same.