Reusable envelope with pre-cut closure flap, method and machine for manufaturing such an envelope
An envelope comprises a closure flap ( 14 ) for closing and opening ( 15 ) by folding over a first wall ( 11 ) of the envelope ( 1 ) and comprises, on an inner face ( 140 ), a first adhesive layer ( 141 ) protected by protection means ( 17 ) formed by a sheet, a second adhesive layer ( 142 ) protected by the protection means ( 17 ) and separated from the first adhesive layer ( 141 ) by a separation space ( 144 ), the flap ( 14 ) being pre-cut by a first and a second weakening line ( 181, 182 ) in the separation space ( 144 ), the sheet extending over the two adhesive layers ( 141, 142 ) and comprising a third weakening line ( 183 ) aligned with the first weakening line ( 181 ) and a fourth weakening line ( 184 ) aligned with the second weakening line ( 182 ). Method and machine for manufacturing such an envelope.
1 . A method for manufacturing an envelope, the method comprising:
forming a closure flap in a wall of the envelope;
placing two adhesive layers on the closure flap that extend parallel to each other and are separated from each other by a separation space;
placing a sheet on the two adhesive layers to form a protection means;
forming a first weakening line in the separation space on the closure flap and a third weakening line in the sheet, wherein the first weakening line and the third weakening line are formed together such that the first weakening line is aligned with the third weakening line;
forming a second weakening line in the separation space on the closure flap and a fourth weakening line in the sheet, wherein the second weakening line and the fourth weakening line are formed together such that the second weakening line is aligned with the fourth weakening line; and
wherein the first weakening line and the fourth weakening line are spaced apart and extend parallel to each other in the separation space.
2 . The method according to claim 1 , further comprising:
forming the envelope from a strip of flexible material on which the adhesive layers and the sheet are placed;
closing the strip to form a tube by joining widths of the strip; and
separating the tube into a plurality of sections leaving the closure flap at a first end of each section of the plurality of sections, wherein each section forms an envelope after closing of a second end of each section opposite the first end of each section.
3 . The method according to claim 2 , wherein the weakening lines are formed after separating the tube into the plurality of sections.
4 . The method according to claim 1 , further comprising:
forming the envelope from a strip of flexible material which closed to form a tube by joining widths of the strip; and
separating the tube into a plurality of sections leaving the closure flap at a first end of each section, wherein each section in the plurality of sections forms an envelope after closing of a second end of each section opposite the first end of each section; and
wherein the adhesive layers and the sheet are placed and the weakening lines are formed after separating the tube into the plurality of sections.