EP1147052A1

EP1147052A1 - Envelope with an adhesive closure and method and device for producing the same

Info

Publication number: EP1147052A1
Application number: EP00903584A
Authority: EP
Inventors: Bert Nolte
Original assignee: Otto Ficker AG
Current assignee: BLESSOF GMBH
Priority date: 1999-01-19
Filing date: 2000-01-18
Publication date: 2001-10-24
Anticipated expiration: 2020-01-18
Also published as: BR0007606A; AU761320B2; CZ20012547A3; ZA200105948B; NO20013458L; ES2253204T3; ATE314269T1; SK10152001A3; HRP20010535A2; AU2542000A; US6732494B1; MXPA01007313A; NZ513438A; DE19901821A1; NO325310B1; DE50011972D1; CZ298416B6; EP1619013A1; EP1147052B1; CA2359099C

Abstract

An envelope (11) consisting of a front side (12) and a rear side (16) which are interconnected by side flaps (19), has a fold-back flap (18) to which a layer of contact adhesive (23) is applied. The adhesive used is a strong contact adhesive which is effective without moistening or activation by any other means. The fold-back flap is laid against the rear side (16) of the envelope for the purposes of transport and storage, an area (22) coated with a parting agent being provided so that the adhesive can be detached before use. The envelope is closed by pressing the otherwise uncoated closing flap (14) onto the adhesive-coated fold-back flap. The adhesive is applied to the fold-back flap (18) by transfer, i.e. the adhesive is applied to the parting agent layer (22) during production and then transferred to the fold-back flap when the latter is redressed.

Description

description

Envelope with adhesive seal and method and device for its manufacture

APPLICATION AREA AND PRIOR ART

Envelopes typically have a front that bears the address or address window, which is followed by a flap on one side and a bottom flap or back that is glued to side flaps that are folded from the front.

There are several systems for closing the envelope after it has been filled:

A rubber coating on the end flap enables closure after it has been moistened. This closure is unsafe because the holding force depends on the degree of moistening and the adhesive also takes a certain amount of time to set, so that when the filling is heavily filled the flap can easily open again before the glue has set.

There are also self-adhesive envelopes with a latex adhesive that is applied to both a rear flap provided on the rear flap and the end flap. This adhesive normally does not adhere to other surfaces, but only to the adhesive layer corresponding to it, so that the closure is achieved by compressing the two similar latex adhesive layers. However, this cohesive adhesive has the disadvantage that it does not close very securely and if necessary, it can also be opened without destruction. Above all, however, it tends to age, so that these so-called SK envelopes, especially under the influence of heat, often lose their closing force completely after a short time.

Pressure-sensitive adhesive envelopes are also used, in which a relatively aggressive adhesive pressure-sensitive adhesive is applied to the end flap. Its adhesive strength is very high, the closure is secure and it is easy to close. The disadvantage, however, is that the pressure sensitive adhesive must be covered by a special siliconized cover strip before use, which must be removed for use. It must then be disposed of, which is disadvantageous. It has become known from DE 43 14 685 A to first apply the pressure-sensitive adhesive to the cover strip and then to glue it onto the closure flap.

From WO 90/11 943 an envelope with adhesive closure has become known in which a pressure sensitive adhesive is applied to the fold-back flap. A part of the back cover to be assigned to this is coated with release agent. In the unused state, the fold-back flap is folded against the release agent layer. After filling the envelope, the fold-back flap is opened and can now be glued to the flap. A disadvantage is that the pressure-sensitive adhesive layer can only cover part of the fold-back flap, because otherwise it would not have to be folded over mechanically. This affects the security of the lock. TASK AND SOLUTION

The object of the invention is to provide an envelope, which includes all types of envelopes, mailing bags, pouches, etc., as well as a method and a device for their production, which use a very effective and aging-resistant adhesive for sealing without any residual products (eg masking tape) and without disadvantages for the shape and usability of the envelope.

This object is achieved by the envelope according to claim 1.

By applying the pressure sensitive adhesive to the separating layer and folding the cover part on which the pressure sensitive adhesive is ultimately to be provided, the pressure sensitive adhesive is then transferred to the cover part not coated with the release agent when it is opened again and is ready for use. The adhesion of the adhesive layer to the non-release agent-coated part (folding flap) is much greater than to the release agent layer. In this way it can be avoided that the pressure sensitive adhesive has to be applied to an area which has to be folded over after its application. This simplifies production, since, for example, a folding roller then only has to have a corresponding recess at the point opposite the area coated with pressure-sensitive adhesive, while the previously uncoated folding flap can be gripped and folded over at any point. It is also possible to provide the fold-back flap largely completely with pressure-sensitive adhesive, especially up to the side edges, in order to increase the security of the closure. This is due to the fact that the pressure sensitive adhesive normally does not require drying. So far the envelopes needed hold-downs on a drying line, for which gaps in the gluing had to be left.

In one embodiment of the invention, the pressure sensitive adhesive is provided only for the fold-back flap. The back of the envelope has a separating layer in the area on which the fold-back flap rests when folded back. The back of the envelope with the separation area provided on it thus covers the adhesive surface of the pressure-sensitive adhesive. It does not interfere with transport or filling. After folding up the

However, the folding flap is free and can be glued to the closing flap that is free of glue.

In another embodiment, the pressure sensitive adhesive can be provided on the closing flap and the separating layer covering it when not in use can be provided on the inside of the envelope, specifically in an area that is exposed by the folded-back folding flap. After the fold-up flap has been folded up, it is glued to the end flap with the adhesive.

The pressure-sensitive adhesives used can be of a conventional type, for example water-based synthetic resin dispersions with adhesive properties with respect to the envelope material used. Hotmelt adhesives can also be used, which are applied at processing temperatures of, for example, 120 ° C to 200 ° C, but have a permanent adhesive effect even at room temperature. It develops a strong adhesive effect without the need for moistening or other activation before gluing. A usable product on an aqueous basis is commercially available under the trade name "Eukalin 5354 Ha", a hot melt under the trade name "Swift H 686/4". The release agent layer, which either as separate coating applied or can already be provided on the material used, may contain, for example, an acrylate resin, silicone acrylate or another silicone compound. The adhesive property is important. Any type of so-called release lacquer can be used, the property of which is based, among other things, on the fact that it closes the pores and therefore does not offer the adhesive a possibility of attack.

Since the pressure sensitive adhesive does not require drying before the envelope is processed, it can be used in the production of the

Envelope the drying section that takes up a large part of the manufacturing machine is eliminated. In order to enable the application of the normal moisture-activatable rubber coating and to keep the drying section short, a very strong scaling or staggering of the envelopes in the machine was previously necessary. This can now be reduced or, under certain circumstances, even completely eliminated.

If the pressure sensitive adhesive is applied to the release agent layer, this occurs before the fold-back flap is folded back. For folding back a folding station is necessary, which is designed so that the envelope does not get stuck on the corresponding folding tools due to its adhesive coating. This can be achieved by a corresponding recess in a folding roller provided in the folding station and / or a release agent coating at this point.

These and further features emerge from the claims and also from the description and the drawings, the individual features being realized individually or in groups in the form of sub-combinations in one embodiment of the invention and in other fields be and can represent advantageous and protectable designs for which protection is claimed here.

The division of the application into individual sections and subheadings does not limit the general validity of the statements made under these.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention is shown in the drawings and is explained in more detail below. The drawings show:

1 to 5 an envelope, seen from the back, in different phases of manufacture or use,

Fig. 6 is a greatly enlarged section along line VI to VI in Fig. 3, but of a variant.

7 is a schematic illustration of a machine for producing the envelope in a side view,

Fig. 8 shows a detail of a folding station for the closure and fold-back flap in a schematic representation, for an envelope according to the

Figures 1 to 3. DESCRIPTION OF THE PREFERRED EMBODIMENTS

1 to 5 show an envelope which is made from a sheet of flat material, preferably paper, by folding and gluing or applying adhesive layers. It is also possible to produce from individual sheets and the materials used can be very different. The envelope 11 shown is an envelope in standard format. In principle, however, it is also possible to produce mailing bags and pouches with and without bottom folds or side folds in the manner to be described.

The envelope 11 has a front side 12 provided for addressing and possibly provided with a viewing window, facing away from the viewer, to which a closure flap 14 is connected by means of a grooved fold line 13. On the opposite side there is a bottom fold 15

Cover back 16 connected, which is folded with its inner surface against the inner surface of the front and extends to just before the fold line 13. A fold-back flap 18 is delimited from it by a fold line 17 which runs parallel to the flap 14 and is dimensioned such that the flap 14 covers it in the closed state of the envelope (FIG. 5), but in the unused state (transport and storage state after) Fig. 3) runs parallel to it.

On the front cover 12 are formed by side folds 20 side flaps 19 which are glued to the side edges of the back cover 16 by two mutually parallel glue seams 21. The adhesive extends from the vicinity of the bottom fold to the fold line 17 of the fold-back flap 18. The area of the rear side adjoining the fold line 17 is provided with a surface with release properties compared to a pressure sensitive adhesive. This area is referred to below as the release agent area 22. It is arranged so that it is the same size or larger than a pressure sensitive area 23 on the fold-back flap. The area of pressure-sensitive adhesive extends almost over the entire width of the fold-back flap and the envelope. The release agent area 22 need only be as wide as the pressure-sensitive adhesive area and positioned so that when the fold-back flap 18 is folded around the fold line 17, the pressure-sensitive adhesive lies exclusively on the release agent area (FIG. 3).

While Fig. 1 shows the envelope before the pressure sensitive adhesive is applied, Fig. 2 shows the envelope shortly before completion, i.e. before folding over the flap 14 and the fold-back flap 18, FIG. 3 shows the finished envelope as it leaves the production machine, is packaged and shipped. The flap 14, which is completely free of adhesive, is folded against an area of the inner surface of the front, while the against

Rear 16 folded fold-back flap 18 covers the PSA area 23 which is brought onto the release agent area 22.

Before using the envelope, i.e. When it is filled, the closure flap 14 is first folded up while the fold-back flap 18 remains in its position according to FIG. 3. This creates a very large and easily accessible filling opening. After filling, the fold-back flap is then also folded up, so that the envelope assumes the position shown in FIG. 4.

This dissolves due to the different ad and

The adhesive layer 23 is separated from the release agent. middle area 22. The pressure sensitive adhesive has thus been transferred to the fold-back flap (FIG. 4). Recesses 27 of the PSA area 23 indicated in FIG. 3 can help here. They form handle recesses for lifting the fold-back flap 18.

After the closure by folding down the closure flap 14 onto the pressure-sensitive adhesive area, which is located on the now folded-back folding flap 18, the envelope is closed (FIG. 5).

The envelope is thus closed by an adhesive and secure, usually non-destructive, adhesive closure that does not have to be freed from the adhesive area beforehand by a separate cover strip. The release agent layer, which can also be referred to as an anti-adhesive layer, can be applied in one or more layers in the form of a lacquer or a different type of coating and does not interfere with the usability or optically since it can be transparent, for example. A particular advantage is that the opened flap, along which the filling material slides, is completely free of glue. It would also be possible to connect the release agent layer to printing the envelope. It is also conceivable that the envelope is made of a material whose outer surface consists of a material that is adhesive with respect to the pressure-sensitive adhesive used, with special measures being used to produce an adhesion between the pressure-sensitive adhesive layer 23 and the corresponding area of the fold-back flap. The inside of the envelope could have a surface without separation properties or this could be created separately in the area of the flap. If, in one variant, the pressure sensitive adhesive is provided on the inside of the closure flap and the release agent covers the opposite area of the inside, then the outside of the envelope can be kept free of release agent, but the closure flap can only be folded outwards after the envelope has been filled, which is less advantageous in use.

The device 30 shown in FIG. 7 for producing the envelopes 11 from a paper web 31 is constructed from the following stations, which are lined up in the manner of a modular system:

A supply roll 33 for the paper web 31 is stored in a roll-off station 32. The web 31 is withdrawn therefrom and passed over a compensation section 34, which, among other things. ensures even web tension. It is also possible to change the roll without stopping the machine. It then runs via a web control station 35, which also carries out a transverse alignment of the web, into a printing station 36, in which printing units 37, which are usually designed as flexographic printing units, are provided for printing on the paper web, for example for the inside of the envelope. In this printing station an order or printing unit 38 is also provided for the application of the release agent area 22.

With the applicator 38, the release agent, for example a so-called release lacquer, is applied, which forms a adhesive surface at the corresponding point, which can be seen, for example, from FIGS. 1 to 3, in which, for example, the paper pores are closed and fibers are covered . In the device 30, this is done on the undivided web, which is therefore not yet tailored to the shape of the subsequent envelope. The release agent layer is then dried by means of a drying device 39, for example using infrared or UV emitters. This is followed in the web running direction 40 by a window cutting station 41, with which the cut-out for an address window may be cut out. In the subsequent window material station 42, transparent window material is fed from a roll 42a and glued or sealed over the window cutout. In the subsequent die cutting station 43, while the web is still connected, the two sides of the web are trimmed in such a way that the edge contour representing the side flaps 19 etc. is created. The various fold lines 13, 15, 17 and 20 are scored simultaneously or in other stations.

In the side flap folding and gumming station 44, which follows the cutting station as closely as possible, the side flaps 19 are folded inwards and provided with two strips 21 of an adhesive which are parallel to one another. In particular at the area adjacent to the fold line 17, the glue strips 21 can also be connected to one another in order to do this

To connect the area particularly effectively. Finally, in the cutting station 45, the material web is cross-cut, i.e. the edge 24 of the recoil flap is separated from the edge 26 of the closure flap. Subsequently, the back or bottom flap 16 is folded around the fold line 15 and glued to the side flaps 19 on each side via the two parallel glue seams 21, but the area of the fold-back flap 18 remains free.

After that, the envelopes are scaled or staggered in the staging station 46. This can have a graduated wheel 47, which is roller-shaped and successively on its surface against the conveying direction has pointing steps or stops that are provided at the desired spacing. Accordingly, this roller can have a sawtooth-like profile, similar to a wheel of a ratchet mechanism. The scaled wheel 47 creates a shingled stream of envelopes 11 in that the incoming envelopes with their leading folded edge 15 due to the arrangement of the scaled wheel and due to the lower peripheral speed of the graduated wheel compared to the incoming envelopes under the leading, already long-refurbished supported envelopes and against the stops, which are designed as steps, run up with the desired spacing that is adjusted to the circumferential speed. A shingled stream of envelopes 11 is produced, which is transported further by a conveying device, for example a belt conveyor. It serves the very high conveying speed of the flow of single envelopes of up to 600 m / min. by overlapping the envelopes. In conventional devices, this was necessary because of the necessary drying of the moisture-activatable glue (rubber coating) or latex glue applied after the staggering, since otherwise the drying section would have become too long and the high conveying speed would have caused problems with the individual envelopes. In addition, the glue was applied continuously with such gumming, ie the staggering left only the area to be gummed from each envelope.

According to the invention, in the subsequent pressure-sensitive adhesive application station, an adhesive application device 49, which works with a rotating roller and is similar to a printing unit, is provided, with which the pressure-sensitive adhesive is applied to the release agent area 22 (cf. FIG. 2). The adhesive effect on the separating layer should be at least so great that the pressure sensitive adhesive adheres to it during processing in the machine. The pressure sensitive area can be so large that it occupies almost the entire fold-back flap 18. This station preferably works with an application roller with one or more individual application segments arranged at a circumferential distance from one another. For a uniform application of adhesive, these can be equipped with a rastered surface, that is to say provided with closely spaced depressions, which is scraped off after the adhesive has been loaded, for example by immersion or transfer from an adhesive-carrying roller. This achieves a particularly uniform and precisely delimited pressure-sensitive adhesive area on the side.

Since no subsequent drying before further processing is necessary for the pressure-sensitive adhesive, the usual drying section to be provided afterwards can therefore be omitted. The staggering of the envelopes in the staggering station also need not be as narrow as is necessary there for the gluing and drying, but is only dependent on the speed at which the application roller of the pressure-sensitive adhesive application station 48 can rotate. In any case, the area to be coated must remain free. Because the drying section is no longer necessary, it is not absolutely necessary, as is otherwise customary in previous machines, to provide a special regulating or aligning station in order to realign the envelopes shifted somewhat from the exact sequence on the drying section. By eliminating the drying section, no hold-downs in the form of belts are necessary, for which gaps in the gluing had to be left. This restricted the complete gluing over almost the entire width of the envelopes, which is possible according to the invention. In a subsequent pull-out station 75, which simultaneously feeds the subsequent fold-back flap folding station 50, the envelopes 11 are separated again.

The individual envelopes 11 then run into the fold-back flap folding station 50. It works according to a scheme which is shown in Fig. 8. The envelope 11 runs with its leading bottom fold edge 15 against a stop 52 provided on an upper folding roller 51, which takes over an alignment function if it becomes necessary. The upper folding roller 51 and the folding roller 53 which rotates underneath in parallel and with the opposite direction of rotation and is somewhat set back in the conveying direction form a gap 54 between them, through which the envelopes run. The folding rollers are provided with suction slits or openings 55, 56, 57 which can be controlled selectively depending on their circumferential position. These are connected to a corresponding suction air source via conventional controls, not shown, of the type of rotary valves. The envelopes arriving on a conveyor or conveyor table 88 are sucked in by the suction openings 55 onto the folding roller 51 at the same time as they start at the stop 52 and are carried in the direction of rotation, which corresponds to the beginning of the conveying direction 40, in the direction of rotation. The suction openings selectively release the envelope in the direction of rotation in good time so that it is caught by a catch pocket 58, which consists of a catch plate 59 directed obliquely upwards and a stop 60 forming the bottom of the pocket. The envelope is stopped in the area of the stop 60 without starting hard, because the suction effect on the lower folding roller 53, which also rotates in the area of the gap 54 in the conveying direction, is activated and the suction slots 57 there capture the closure flap 14 and take it with it the rotation of the folding roller. A series of narrow suction openings or slots 56 are activated in good time and are arranged on the upper folding roller 51 in the edge region of a recess 61.

At the area 23 occupied by the pressure sensitive adhesive (above the release agent area 22) there is a recess 68 in the upper folding roller 51, which may optionally have a release agent layer 62 made of polytetrafluoroethylene (PTFE) at its base. The fold-back flap 18 is gripped by folding surfaces 69, 70 which have suction openings 56, 56a. The surfaces 69, 70, which lie in the area of an approximately triangular recess 61 which can be seen in detail in FIG. 8, are designed in such a way that the fold-back flap is sucked in by the suction opening 56 at a flatter angle in its area adjacent to the fold line 17. Then when the envelope 11 with the fold line 13 comes close to the fold gap 63 due to the rotation of the folding rollers, then the suction air at the suction slot 56 is switched off and instead that at the suction gap 56a, which belongs to the surface 70, is switched on. A simultaneous connection could also be made. This surface is placed at a larger angle with respect to the tangent to the folding roller 51.

Since the folding-back flap 18 unfolds very quickly at the high working speed, it can buckle or bend due to dynamic forces and, supported by the suction effect of the openings 56a, can rest against the surface 70. When pulling the envelope off the top

Folding roller 51 then starts the refolding flap from surface 69, so to speak "peeled off" after the vacuum is switched off and, if necessary, actively broken down. As a result, when the fold-back flap 18 is folded over, a harmonious and gentle transfer into the individual folding positions will take place. This enables high working speeds with great reliability. A curve between the surfaces 69, 70 or one overall curved surface could possibly improve this effect.

When the vacuum is switched off, the openings and channels carrying the suction air are usually ventilated via the described valves or rotary slide valves in order to release the vacuum. To accelerate this process, instead of passive ventilation, an active one can be provided, in that compressed air is supplied via the valves which effect the ventilation. Although this has already been proposed for the rejection of cutting waste, it is unusual in the case of folding rollers because active rejection of the fold-back flap is undesirable per se. The active ventilation should therefore be limited to a level that causes rapid detachment.

When the folding rollers 51, 53 are rotated synchronously, the flap 14 is folded over on the folding line 13 and the fold-back flap 18 over the folding line 17, and the entire envelope is drawn into a folding gap 63 between the lower folding roller 53 and a take-off roller 64. The closure flap 14 and the fold-back flap 18 are correspondingly applied to the locations of the envelope which can be seen in FIG. 3, the pressure-sensitive adhesive region 23 resting on the release agent region 22 being applied and pressed onto the hitherto uncoated fold-up flap 18. The pressure which causes the adhesive transfer from the separating layer to the fold-back flap is either applied in the device or only during packaging or in the packaging.

The double-line gluing of the side flaps over the two side flap two parallel glue seams 21 and a particularly fast setting adhesive ensure a particularly safe gluing and also that the glue has set despite the high conveying speed when the Envelope reached the folding station. As a result of this and due to the three-layer envelope structure in this area (front, back and side flap) together with the glue in between between the bottom fold 15 and the fold line 17, this area is relatively stiff, so that the fold-back flap can be folded along the fold line 17 without any problems. Above all, it is avoided that the adhesive closure between the side flaps and the back of the envelope is torn open by the folding over of the fold-back flap. Furthermore, these two parallel glue seams make it possible to carry out a glue covering a relatively large area without applying so much glue that it is pressed out to the side or in the direction of the fold-back flap.

In the subsequent depositing station 65, the flow of the envelopes is deposited on a conveyor 67 by means of a depositing drum 66 (fan wheel) and passed on to the packaging.

Depending on the type and configuration of the envelopes, 30 stations of this type can be provided for the individual processing to be carried out, or in some cases stations can be exchanged for others or omitted. Another sequence is also possible.

FIG. 6 shows an enlarged partial section, in which, in particular, the material thicknesses, in order to be able to be represented, are greatly increased. The release agent layer 22 is applied to a primer layer 22 'which on the one hand prepares the release agent, e.g. by closing the paper pores and, on the other hand, can promote adhesion between the paper and the release agent. You can do this in the following

Fig. 7 described another application in a printing station, depending on the type of primer, with or without a drying or hardening device before the release agent is applied.

FIG. 6 further shows that a rear grip area 27 ', which is adjacent to the edge 24, can be provided on the fold-back flap 18, which is not outside the pressure-sensitive adhesive area 23 and from this by a pre-break line 27' '(scoring, line embossing) or the like.) This strip-shaped grip region 27 'can be easily set up and gripped with the finger in order to be able to pull off and set up the folding flap 18.

The invention thus preferably creates an envelope consisting of a front and a back, which are connected to one another via side flaps, has a fold-back flap to which a layer of pressure-sensitive adhesive is applied. It is a strong-acting, adhesive pressure-sensitive adhesive that is effective without moistening or other activation. The fold-back flap is placed on the back of the envelope for transport and storage, with a release agent-coated area being provided to enable the adhesive to be detached again before use. To close the otherwise uncoated closure flap is pressed onto the adhesive-coated folding flap.

The pressure sensitive adhesive is applied to the fold-back flap by transfer, i.e. the pressure sensitive adhesive is used in the

Production applied to the release agent layer and taken over by the fold-back flap when erecting it.

Claims

Expectations

1. Envelope which has a flap (14) adjoining an envelope front (12) and a fold-back flap (18) which can be folded up from a storage state into a closed state and which in the storage state is folded up to the envelope rear side (16), with a Adhesive closure by means of a pressure sensitive adhesive (23) which, in the stored state, bears against a cover (22) with separation properties formed by surface areas of the envelope, and wherein the fold-back flap (18) is glued to the closure flap (14) in the closed state, characterized in that the pressure sensitive adhesive ( 23), the surface of the pressure-sensitive adhesive area and the separating area (22) are designed to cooperate in such a way that the pressure-sensitive adhesive (23) applied to the separating area (22) has its upper side on the surface of the pressure-sensitive adhesive area (23) of the envelope (11) pressed against it. is glued, the pressure-sensitive adhesive layer in the closed state is detached from the separation area (22) and which is now the Surface of the pressure-sensitive adhesive layer (23) forming the former underside of the pressure-sensitive adhesive layer has pressure-sensitive adhesive properties.

2. Envelope according to claim 1, characterized in that the pressure sensitive adhesive (23) on the fold-back flap (18) is provided and the back of the envelope (6) has at least in a separating area (22), against which the pressure sensitive adhesive area (23) occupied by the pressure sensitive adhesive rests, has the surface with separating properties.

3. Envelope according to claim 1 or 2, characterized in that the surface area with release properties has a release agent layer, which contains in particular acrylate resins, silicone acrylate, other silicone compounds or the like.

4. Envelope according to one of the preceding claims, characterized in that the separating region has two layers applied one above the other, namely a primer layer which forms a primer and a separating agent layer, the adhesion of which to the primer layer is better than to the pressure-sensitive adhesive.

5. Envelope according to one of the preceding claims, characterized in that the pressure sensitive area (23) has on its on the outer edge of the folding flap (18) adjacent edge recesses (27) or a grip zone (27 ') delimiting pre-break (27' ') .

6. Envelope according to one of the preceding claims, characterized in that the pressure sensitive area (23) extends close to the outer edges (20) of the envelope.

7. Envelope according to one of the preceding claims, characterized in that the front and back (12, 16) of the envelope (11) connecting side flaps (19) each have two mutually parallel glue seams (21) sen, which may be connected to each other at at least one end.

8. A method for producing an envelope which has a closing cap (14) adjoining an envelope front side (12) and a fold-back flap (18) which can be folded up from a storage state into a closed state and which folds up to the envelope rear side (16) in the storage state and which has an adhesive closure by means of a pressure sensitive adhesive (23) which, in the stored state, rests with a separation area (22) with separation properties formed on surface areas of the envelope, the fold-back flap (18) being glued to the closure flap (14) in the closed state, characterized in that a surface area of the envelope (11) forming a separating area with a

Provide release agent, this dried or hardened and that the pressure sensitive adhesive (23) is applied to the surface area of the envelope (11) provided with release agent (22) and then a foldable area (18) of the envelope is pressed against the pressure sensitive adhesive (23), whereby the pressure sensitive adhesive becomes detached from the surface provided with release agent after the foldable area has been lifted off.

9. The method according to any one of claims 8, characterized in that the folding over of the fold-back flap (18) and / or the closing flap (14) takes place by means of controlled suction air support, and the termination of the suction effect is accelerated by adding compressed air.

10. The method according to any one of claims 8 or 9, characterized in that the pressure sensitive adhesive (23) is applied to a stream of successive envelopes in regions spaced apart in the conveying direction, the stream optionally with little or no mutual overlap of the envelopes (11 ) runs.

11. The device, in particular for producing the envelope according to one of claims 1 to 7 and / or for carrying out the method according to one of claims 8 to 10, characterized in that it has a release agent application station (36) in the manner of a printing unit (38) for application and optionally a drying device (39) for drying or curing the release agent and that it has a pressure-sensitive adhesive application station (48) which has an application roller with one or more individual application segments arranged at circumferential spacing from one another with possibly rastered the adhesive feed has a doctored surface and / or is arranged for application to an area (22) previously provided with release agent.

12. The apparatus according to claim 11, characterized in that it has a folding station (50) for folding the U flap (18) and optionally the flap (14), the folding station having a folding roller (51) for the

Has a folding flap (18) which has a recess (68) and / or a release agent surface (62) in a region of the envelope (11) provided with pressure sensitive adhesive (23).

13. The apparatus according to claim 12, characterized in that the folding roller (51) has a suction area with suction openings (56, 56a), which lies in the region of a recess (61) of the folding roller (51) and its suction surfaces (69, 70) to the outer edge (24) of the fold-back flap (18) form a larger angle to the tangent to the folding roller (18).

14. The apparatus according to claim 12 or 13, characterized in that the folding stations (50) directly to a pull-out station (75) in which the envelopes (11) are separated, which feeds the folding station (50) directly.

15. The apparatus according to claim 11 to 14, characterized in that the application station (36) is arranged subsequent to a roll for a material web (31) from which the envelopes (11) are made, and optionally the application station (36) Fixing station (39) for drying or curing the release agent, in particular by means of UV lamps, is assigned.

16. The device according to any one of claims 11 to 15, characterized in that it comprises the envelopes (11) between a separating cutting station (45) and the closing and folding flap folding station (50) in the form of an only slightly staggered or unstaggered flow of successive envelopes has promoting conveyor.

17. The device according to one of claims 11 to 16, characterized in that the folding station (50) connects to the pressure-sensitive adhesive application station (48) without an intermediate drying station.

18. Device according to one of claims 11 to 17, characterized in that it has a relay station (46) which has at least one relay roller (47) which cooperates with the leading edge (15) of each envelope (11) and that this Relay roller (47) has stops or steps on its circumference.

19. Device according to one of claims 11 to 18, characterized in that the folding roller (51) has an alignment stop (52) for the bottom edge (15) leading in the conveying direction (40).