REUSABLE ENVELOPE WITH PRE-CUT CLOSURE FLAP, METHOD AND MACHINE FOR MANUFATURING SUCH AN ENVELOPE

Abstract

A-reusable envelope made, notably, of a flexible material such as paper. A method for manufacturing the envelope as well as a machine for manufacturing the envelope.

Claims

1. An envelope comprising an opening and a closure flap to close the opening, the closure flap being foldable down on to a first wall of the envelope and comprising on an inner face a first adhesive layer protected by protection means a second adhesive layer protected by protection means and separated from the first adhesive layer by a separation space, the flap being pre-cut by a first and a second weakening line in the separation space characterised by the fact that the protection means consists of a sheet extending over both adhesive layers the sheet comprising a third weakening line aligned with the first weakening line and a fourth weakening line aligned with the second weakening line.

2. The envelope as per claim 1, in which the sheet and the flap are stuck between the weakening lines.

3. The envelope as per claim 1, in which the weakening lines are lines of perforations.

4. The envelope as per claim 1, in which the weakening lines are lines pre-cut in the thickness.

5. The envelope as per claim 1, wherein the envelope comprises a second wall including a second flap extending from and linked to the first wall along outer edges of the first wall.

6. The envelope as per claim 5, in which the first and second walls are linked by gussets extending along the outer edges.

7. The envelope as per claim 1, in which the flap comprises an incision in at least one end of at least one of the weakening lines.

8. A process for manufacturing an envelope as per claim 1, whereby a closure flap is formed in the prolongation of a second wall of the envelope two adhesive layers are placed on the flap parallel to each other and separated by a separation space, wherein the sheet is placed on the two adhesive layers to form the protection means, the sheet and the flap together are weakened to form the first weakening line in the separation space on the flap aligned with a third line of perforations in the sheet , and a second line of perforations in the separation space on flap aligned with a fourth weakening line in the sheet, the weakening lines extending in parallel in the separation space.

9. The process as per claim 8 whereby the envelope is formed from a strip of flexible material on which firstly adhesive layers and the protection sheet are placed, then the strip is closed to form a tube by joining the widths of the strip, then the tube is separated into sections leaving the flap at a first end of the section, each section forming an envelope after the closing of a second end opposite the first end.

10. The process as per claim 9 in which the weakening lines are made after the separation of the tube into sections.

11. The process as per claim 8 whereby the envelope is formed from a strip of flexible material closed to form a tube by joining the widths of the strip, then the tube is separated into sections leaving the flap at a first end of the section, each section forming an envelope after the closing of a second end opposite the first end, and flap on which adhesive layers, protection sheet and weakening lines are placed.

12. A machine for manufacturing an envelope using the process as per claim 8, the machine comprising a tube forming device to form a tube from a strip of flexible material, a separation device to separate a section from the tube at the front of the tube while forming a closure flap at one end of the tube section, the flap extending the section beyond the end of a first wall, the machine being characterised by the fact it comprises placement means for placing two adhesive layers on the strip of material in parallel with each other and separated by a separation space at the level of the closure flap, the placement means being designed to also place a sheet forming protection means on both adhesive layers, the machine also comprising weakening means for making together a first weakening line and a third weakening line respectively on the flap and the sheet aligned and in the separation space of the flap, and together a second weakening line in the separation space of the flap aligned with a fourth line of the sheet, the weakening lines extending in parallel in the separation space.

13. The machine as per claim 12 in which the placement means is situated upstream of the tube formation device.

14. The machine as per claim 12 in which the placement means is situated downstream of the separation device.

15. The machine as per claim 12 in which the weakening means is situated downstream of the tube separation device and of the placement means.

16. The machine as per claim 12, wherein the machine comprises a base formation device to form the envelope with each tube section by closing the front of the tube section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The invention will be better understood and other special features and advantages will be revealed by reading the description below, the description referring to the appended drawings among which:

[0029] FIG. 1 is a perspective view of an envelope conforming to one of the invention's accomplishment modes;

[0030] FIG. 2 gives a view similar to FIG. 1 of the envelope ready to be closed for the first time;

[0031] FIG. 3 gives a view similar to FIG. 1 of the envelope closed for the first time;

[0032] FIG. 4 gives a view similar to FIG. 1 of the envelope being opened;

[0033] FIG. 5 gives a view similar to FIG. 1 of the envelope ready to be closed for the second time;

[0034] FIG. 6 gives a view similar to FIG. 1 of the envelope closed for the second time;

[0035] FIG. 7 gives a schematic view of the envelope manufacturing machine of FIG. 1 as per a first accomplishment mode;

[0036] FIG. 8 gives a schematic view of the envelope manufacturing machine of FIG. 1 as per a second accomplishment mode.

DESCRIPTION OF THE ACCOMPLISHMENTS MODES

[0037] An envelope 1 conforming to the invention's accomplishment mode is shown in FIGS. 1 to 6. The envelope is made of a flexible material such as paper or a woven synthetic material or non-woven textile. Envelope 1 comprises a first wall 11 and a second wall 12 superimposed and linked by gussets 13 extending along the outer edges 110. Envelope 1 comprises a closure flap 14 extending from the second wall 12 and which extends beyond an opening 15 in envelope 1 delimited between walls 11, 12 and gussets 13. Opposite flap 14, envelope 1 comprises a tab 16 extending from the second wall 12, folded on to the first wall 11 and stuck to it to form a base. Envelope 1 can be closed by folding closure flap 14 along a flap line 150 extending along the opening 15 and separating closure flap 14 from the second wall 12, then by turning down flap 14 on to the first wall as detailed below.

[0038] Closure flap 14 comprises on an inner face 140 a first adhesive layer 141 extending in parallel with the line on flap 14 and a second adhesive layer 142 extending in parallel with the line on flap 14 between said line and the first adhesive layer 141. The first and second adhesive layers 141, 142 are separated by a separation space 144. A sheet 17 forming a protection means covers the first adhesive layer 141 and the second adhesive layer 142 to protect them. Sheet 17 is for example made of siliconized paper.

[0039] Flap 14 is pre-cut with a first and second weakening line 181, 182 in the separation space 144, likewise sheet 17 which comprises 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. A third adhesive layer covers the separation space 144 between the weakening lines to stick sheet 17 and flap 14 between them between the weakening lines 181, 182, 183, 184. In the example shown, the weakening lines 181, 182, 183, 184 are lines of perforations. Flap 14 comprises an incision 145 at one end of the first and of the second weakening lines 181, 182.

[0040] When using such an envelope 1, a user inserts a content, not shown, into the envelope 1 through opening 15, then removes the sheet 17 that covers the first adhesive layer 141 by tearing it along the fourth weakening line 184, as shown in FIG. 2, leaving part 17a of the sheet in place. They turn down flap 14 by folding along the line of flap 14 and press the first adhesive layer 141 on to the first wall 11 in order to stick flap 14 to it. Envelope 1 is then closed, as shown in FIG. 3, and can be sent. 41. When they receive envelope 1, the addressee pulls on the entity formed by the part of flap 14 situated between weakening lines 181, 182 and the corresponding part of sheet 17. To do this, they are assisted by the incisions 145 which delimit a tear initiation. The part that is removed forms a strip 146 that separates flap 14 into two parts 14a, 14b, as shown in FIG. 4, one 14a which remains stuck to the first wall 11, and another part 14b which opens and releases opening 15, as shown in FIG. 5.

[0041] Envelope 1 can be re-used by the addressee. To do this, they remove the rest of sheet 17a to release the second adhesive layer 142, fold flap 14 along the line of flap 150 and press the second adhesive layer 142 on to the first wall 11 in order to stick flap part 14b to it, as shown in FIG. 6.

[0042] Alternatively, the weakening lines may be lines pre-cut in the thickness of flap 14 and of sheet 17.

[0043] In order to manufacture an envelope 1 such as described above, a machine, such as outlined in FIG. 7, can be used. Such a machine successively comprises an unwinding device 2 in the unwinding direction to unwind a strip 3 of flexible material such as a roll of paper to unwind it, means of perforation 4 for making perforations transversally on strip 3 of material, means of placement 5, a tube formation device 6 for forming a tube from the strip 3 of material, a separation device 7 for separating a section 3′ from the tube at the front while forming closure flap 14 at the rear end of tube section 3′, weakening means 8 and a base formation device 9 for forming envelope 1 with each tube section 3′ by closing the front of tube section 3′. The envelopes 1 formed are stacked at the output from the base formation device 9.

[0044] The tube formation device 6 is a conventional device and will not be described in greater detail. The separation device 7 comprises a gripping station 71 and a tearing station 72 such as described in document WO 2016/097310 A1. The functioning of this separation device 7 is not described here, except that it makes it possible to deliver to the weakening means 8 tube sections 3′ comprising a tab 16 at the front of section 3′, which will then make it possible to form the base of envelope 1, and flap 14 at the rear of section 3′, the second wall 12 being situated in the lower part. A waste piece, not shown, is extracted from the tube by tearing station 72 and suction means 73 to uncover flap 14.

[0045] The base formation device 9 is a conventional device and will not be described in greater detail. It is used to fold and stick the tab 16 to close the envelope.

[0046] The placement means 5 is designed to place the first, second and third adhesive layer 141, 142, 143 on the strip 3 of material and cover them with sheet 17 at the level of what will become closure flap 14. To do this, sheet 17 arrives continuously, is cut by a cutting station 51 and receives the adhesive layers in a bonding station 52. It is then taken in a transfer station 53 which sucks it on to the surface of a roller 530 and presses on the strip 3 of material to place the sheet 17 and the adhesive layers 141, 142, 143. The face of sheet 17 in contact with adhesive layers 141, 142, 143 is siliconized in such a way that the sheet 17 can then be extracted whereas the adhesive layer 141, 142, 143 remains on the strip 3 of material.

[0047] The weakening means 8 comprises two notched blades 81, 82 protruding from a roller 83 and a counter-roller 84 comprising a soft surface. By gripping the flap 14 of tube section 3′ between the roller 83 and counter-roller 84, the first weakening line 181 and the third weakening line 183 are made respectively on the aligned flap 14 and sheet 17 and in the separation space 144 of flap 14, and the second weakening line 182 is made in the separation space 144 of flap 14 aligned with the fourth weakening line 184 of sheet 17, the weakening lines having the shape of lines of perforations.

[0048] In a second accomplishment mode, the machine, such as shown in FIG. 8, is distinguished from the first accomplishment mode in that the placement means 5′ is situated downstream of the tube separation device 7 and upstream of weakening means 8.

[0049] The invention is not limited to the accomplishment modes that have just been described simply as an example. The envelopes can be made without gussets, that is to say that the first wall and the second wall are connected to each other by a simple fold along the outer edges. The weakening means can be placed between the placement means and the tube formation means.