EP1147052B1 - Envelope with an adhesive closure and method and device for producing the same - Google Patents

Abstract

The envelope (11) comprises a closure flap (14) and a rear flap (18) which is provided with an adhesive layer (23). The rear flap is pivotable into a closure position from its folded storage position on an envelope surface (22) treated with a separation agent. Independent claims are also included for: (i) A method for producing the envelope. The method involves treatment of a part of the envelope rear surface with a separation agent; and (ii) apparatus for producing the envelope comprising a station for application and drying of the separation agent.

Description

AREA OF APPLICATION AND PRIOR ART

Envelopes usually have an address or one Address window bearing front, to which one-sided a flap connects, and on the other side a bottom flap or back, with side flaps glued, which are folded from the front.

To close the envelope after it has been filled There are several systems:

A gumming of the final flap allows for their Moistening a closure. This closure is uncertain because the holding force depends on the degree of moistening and the Glue also requires some time for setting, so that with heavy filling, the flap pops up easily, before the glue has set.

There are also self-adhesive envelopes with a latex adhesive, on both on a provided on the back folding flap as well as the final flap is applied. This Adhesive usually does not adhere to other surfaces, but rather only on the corresponding adhesive layer, so that the Closure by squeezing the two similar Latex adhesive layers takes place. This cohesive glue has but the disadvantage that it does not close very safe and if necessary, it can also be opened non-destructively. Above all, it tends he is aging, so that these so-called SK envelopes, in particular under heat often after a short time their Losing clamping force altogether.

There are also pressure-sensitive adhesive envelopes in use, in which the final flap is a relatively aggressive adhesive is applied. Its adhesive power is very high, the closure is safe and it is easy to lock. The disadvantage However, it is that the pressure-sensitive adhesive before use through a special, siliconized cover strip must be covered, which must be deducted for use. He must be disposed of afterwards, which is disadvantageous. That's it become known from DE 43 14 685 A, the pressure sensitive adhesive first Apply to the cover strip and then this on the Stick on the flap.

From WO 90/11 943 an envelope with adhesive closure is known become, with which a pressure-sensitive adhesive on the fold-back flap is applied. A part of the envelope back to be assigned to this one is coated with release agent. In the unused Condition is thus the fold-back flap against the release agent layer worked. After filling the envelope, the Fold-back flap unfolded and can now with the Glued shut flap. A disadvantage is that the pressure-sensitive adhesive layer only a part of the Rückfaltklappe otherwise they can not be folded over by machine would. This affects the security of the closure.

TASK AND SOLUTION

The object of the invention is an envelope, including all types of Envelopes, mailers, pouches etc. are understood as well as a To provide a method and a device for its manufacture, which is suitable for closing the use of a very effective and aging resistant Adhesives without residual products (e.g., cover strips) and without disadvantages for the shape and usability of the envelope.

This object is achieved by the envelope according to claims 1 and 2 and by the method according to claim 9 and the device according to Claim 12 solved.

By applying the pressure sensitive adhesive (i.e., the pressure sensitive adhesive layer) to the release liner and overfolding of the cover part on which the pressure-sensitive adhesive is finally provided should be the pressure-sensitive adhesive then when re-opening this area transferred to the non-release-coated envelope part and is operational. The adhesion of the adhesive layer to the non release-coated Part (fold-back) is much larger than at the release agent layer. In this way it can be avoided that the pressure-sensitive adhesive an area must be applied, which folded over after its application must become. This facilitates the production, for example a folding roller then only a corresponding recess at the site must have, which is opposite to the area coated with pressure-sensitive adhesive, while the hitherto uncoated folding flap at any point can be grasped and folded over. It is also possible to use the fold-back flap largely completely provided with pressure-sensitive adhesive, especially until close to the side edges to increase the lock security. To contributes to the fact that the pressure-sensitive adhesive does not normally dry needed. So far needed the envelopes on a dry stretch hold down, be left for the gaps in the gluing had.

In one embodiment of the invention, the pressure-sensitive adhesive is only intended for the fold-back. The envelope back has a release layer in the area where the fold-back flap in the folded-back state rests. Thus, covers the Umschlagrückseite with its intended separation area the adhesive surface of the pressure-sensitive adhesive. He does not bother when Transport still at the filling. After folding up the It is, however, free and can be folded with glue glued free closing flap.

In another embodiment, the pressure sensitive adhesive on the Be provided in the final flap and him in the unused Condition-covering release layer on the inside of the envelope be provided, in an area covered by the turned down foldback flap is exposed. After this Hitting the fold-back flap will do this with the pressure-sensitive adhesive glued on the final flap.

The pressure-sensitive adhesives used can be conventional, for example Synthetic resin dispersions on an aqueous basis with adhesive properties to the cover material used. Hotmelts can also be used which are processed at processing temperatures of e.g. 120 ° C to 200 ° C, but a permanent adhesive effect even at room temperature. He is developing a strong Adhesive effect without moistening or other activation would be necessary before bonding. A usable product Aqueous based is under the trade name "Eukalin 5354 ha "in the trade, a hotmelt under the trade name "Swift H 686/4". The release agent layer, either as applied separate coating or even on the used material can be provided, for example an acrylate resin, silicone acrylate or another Silicone compound included. Important is the dehäsive property. It can be any kind of so-called release varnish be used, their property among other things due to the fact that it closes the pores and thus the pressure-sensitive adhesive no chance to attack.

As the pressure sensitive adhesive before further processing of the envelope No drying needed, can be used in the production of Envelope which is a big part of the manufacturing machine engaging dry track omitted. To the application to allow the normal moisture activatable gum and to keep the dry stretch short, was previously one very strong scaling or staggering of the envelopes in the Machine necessary. This can now be reduced or under some circumstances completely eliminated.

When the pressure-sensitive adhesive is applied to the release agent layer This happens before the foldback flap folds back. For folding back a folding station is necessary, which is formed is that the envelope due to its pressure-sensitive adhesive coating not on the appropriate folding tools Keeps hanging. By a corresponding recess on an in the folding station provided folding roller and / or a release agent coating At this point this can be achieved become.

These and other features are excluded from the claims also from the description and the drawings, wherein the individual features in each case alone or to several in the form of subcombinations in one embodiment of the invention and realized in other fields could be.

The subdivision of the application into individual sections as well between-headings restricts those made under them Statements not in their generality.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 bis 5

einen Briefumschlag, von der Rückseite her gesehen, in verschiedenen Phasen der Herstellung bzw. Nutzung,

Fig. 6

einen stark vergrößerten Schnitt nach Linie VI bis VI in Fig. 3, jedoch von einer variante,

Fig. 7

die schematische Darstellung einer Maschine zur Herstellung des Briefumschlags in Seitenansicht,

Fig. 8

ein Detail einer Faltstation für die Verschluß- und Rückfaltklappe in schematischer Darstellung, für einen Umschlag nach den Figuren 1 bis 3.

An embodiment of the invention is illustrated in the drawings and will be explained in more detail below. In the drawings show:

Fig. 1 to 5

an envelope, seen from the back, in different stages of manufacture or use,

Fig. 6

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

Fig. 7

the schematic representation of a machine for the production of the envelope in side view,

Fig. 8

a detail of a folding station for the closure and folding back flap in a schematic representation, for an envelope according to the figures 1 to 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figs. 1 to 5 show an envelope, which consists of a Web of flat material, preferably paper, by folding and Bonding or application of adhesive layers is made. It is also a production of single sheets possible and the used materials can be very different. Of the illustrated envelope 11 is an envelope in the standard format. Basically, however, is the production of mailing bags and bags with and without bottom fold or gussets possible in the manner to be described.

The envelope 11 has an intended for addressing and possibly provided with a viewing window, facing away from the viewer Front 12, to which by means of a grooved Fold line 13 a closure flap 14 connects. On the opposite side is a Bodenfalz 15 a Envelope back 16 connected with its inner surface folded against the inner surface of the front and up just before the fold line 13 is enough. From her is through one Fold line 17 delimited a fold-back flap 18 which is parallel to the flap 14 extends and is dimensioned so that the Closure flap 14 in the closed state of the envelope (Figure 5) covers it, but in the unused state (transport and storage condition of FIG. 3) in parallel beside her runs.

To the front cover 12 are by Seitenfalze 20th Side flaps 19 integrally formed with the side edges of the Envelope back 16 by two parallel glue seams 21 are glued. The bonding ranges from the vicinity the bottom fold to the fold line 17 of the fold-back flap 18th

The adjacent to the fold line 17 region of the back is with a surface having release properties opposite one Provided adhesive. This area will be referred to as Release agent area 22 referred to. He is so arranged it is equal to or larger than a pressure-sensitive adhesive area 23 on the fold-back flap. The pressure sensitive adhesive area is almost enough across the entire width of the fold-back flap and the envelope. The release agent area 22 only needs as wide as the Adhesive area and be positioned so that in the folding the fold-back flap 18 about the fold line 17 of the Pressure-sensitive adhesive lies exclusively on the release agent area (Fig. 3).

While Fig. 1 the envelope before the application of the Pressure-sensitive adhesive 23 'shows, Fig. 2 short the envelope. before the Completion, i. before folding the flap 14th and the fold-back flap 18, Fig. 3 shows the finished Envelope as it leaves the manufacturing machine, packed and shipped. In this case, the flap 14, the of Glue is completely free, against an area of the inner Surface of the front folded while against the Rear 16 folded foldback flap 18 the pressure-sensitive adhesive area 23 covers, which is brought to the release agent portion 22.

Before using the envelope, i. his filling, will First, the flap 14 folded up while the Folding flap 18 still remains in its position according to FIG. 3. This will make a very large and easily accessible Filling opening formed. After filling then the Folding flap folded up, so that the envelope the position 4 assumes.

It dissolves due to the different ad- and Dehäsivverhältnisse the pressure-sensitive adhesive layer 23 "of the release agent area 22. The pressure-sensitive adhesive is thus on the fold-back flap transferred (Fig. 4). In this case, in Fig. 3rd indicated recesses 27 of the pressure-sensitive adhesive area 23 help. They form gripping recesses for lifting the fold-back flap 18th

After closing by folding down the flap 14 on the PSA area, located on the now unfolded foldback flap 18 is the envelope closed (Fig. 5).

The envelope is thus protected by an adhesive and safe, usually not nondestructive openable adhesive closure closed, without the pressure-sensitive area previously by a Separate cover strip had to be freed. The release agent layer, which is also referred to as an anti-adhesion layer can be in the form of a varnish or a different kind Coating applied one or more layers be neither the usability nor visually, as he e.g. can be transparent. A special advantage lies in that the opened flap on which the contents slides along, is completely free of glue. It would be too possible, the release agent layer with a print of the To connect envelope. It is also conceivable that the envelope is made of a material whose outer surface is made of a relative to the pressure-sensitive adhesive used 29 'Dehäsiven material exists, whereby by special measures a liability between the pressure-sensitive adhesive layer 23 "and the corresponding area the fold-back flap is made. The inside of the Envelope could be a surface without release properties or this could be separate in the flap area be generated.

If, in one variant, the pressure-sensitive adhesive on the inside the closure flap is provided and the release agent the covered on the opposite side of the inside, then Although the envelope outside can be kept free of release agent be, but the flap can only after filling of the envelope are folded outward, resulting in the use less advantageous.

The device 30 shown in Fig. 7 for the production of Envelopes 11 from a paper web 31 is from the following, after Type of a modular system lined up stations built up:

In a unwinding station 32 is a supply roll 33 for the Paper web 31 stored. The web 31 is deducted from this and passed over a compensation path 34, the u.a. for one uniform web tension ensures. It may also be the possibility a roll change be provided without machine stop. she then runs over a railway control station 35, which is also a Transverse alignment of the web, in a printing station 36th one, in the printing units 37, mostly as flexographic printing are formed, for printing the paper web, for example for the inside of the envelope, are provided. In this Print station is also an order or printing unit 38 for the Application of the release agent portion 22 is provided.

With the applicator 38 is the release agent, for example a so-called release varnish, applied to the corresponding Place, for example, from Figures 1 to 3, a dehäsive surface forms, in which For example, the paper pores closed and covered fibers are. In the device 30, this is done on the undivided course, that is not yet according to the form the later envelope is tailored.

Subsequently, the release agent layer by means of a Drying device 39, for example with infrared or Dried UV lamps. This is followed in web direction 40 a Fensterausschneidestation 41, with the possibly the cutout is cut out for an address window. In the subsequent window material station 42 is of a Roll 42a transparent window material fed and over glued or sealed the window. In the following Form cutting station 43, at still coherent web, the two sides of the web so circumcised, that the side flaps 19, etc. performing Edge contour arises. At the same time or in other stations a grooving of the various fold lines 13, 15, 17 and 20.

In the Seitenklappenfalz- and -gummierstation 44, the possible close to the mold cutting station, the Side flaps 19 folded inwards and with two to each other provided parallel strip 21 of an adhesive. Especially at the adjacent to the fold line 17 area can Glue strips 21 also be connected to each other To connect area particularly effective. Finally will in the separating cutting station 45, the material web is cross-cut, i.e. the edge 24 of the fallback flap is from the edge 26 of the flap separately. Subsequently, the Rear or bottom flap 16 folded about the fold line 15 and over the two parallel glue lines 21 on each side glued to the side flaps 19, but the area the fold-back flap 18 remains free.

After that, a scaling or staggering of the envelopes takes place the relay station 46 instead. This can be a relay 47 have, which is cylindrical and formed on his Surface sequentially opposite to the conveying direction has pointing steps or stops in the desired Staffelabstand are provided. This roller can therefore accordingly have a sawtooth profile, similar to a wheel a ratchet mechanism. The relay wheel 47 creates a shingled stream of envelopes 11 in that the incoming Envelopes with their leading fold edge 15 by the arrangement of the relay wheel and by the opposite the incoming envelopes lower peripheral speed of the relay wheel under the leading, already slower promoted envelopes and against as grades trained stops with the desired and on the Accelerate peripheral speed coordinated clearance spacing. The result is a scaly stream of envelopes 11, the by a conveyor, e.g. Belt conveyor, continue is transported. It serves the very high conveying speed the flow of single envelopes up to 600 m / min. by reducing the overlap of the envelopes. In conventional devices this was because of the necessary drying of the applied after staggering moisture-activated glue (rubber coating) or latex gluing necessary, otherwise the drying section is too long would have become and the high conveying speed at the individual envelopes would have led to problems. Furthermore in such gumming the glue application was continuous made, i. the graduation only left of each envelope free the area to be gummed.

According to the invention, in the following pressure-sensitive adhesive application station one similar to a rotating roller a printing unit working adhesive applicator 49th provided with the pressure-sensitive adhesive on the release agent area 22 is applied (see Fig. 2). The adhesive effect on the Separating layer should be at least so large that the pressure-sensitive adhesive while processing in the machine is liable.

The pressure-sensitive adhesive area can be so large that it almost the entire folding door 18 occupies. This station works preferably with an applicator roll having one or more individual, spaced apart circumferentially application segments. These can be used for uniform adhesive application with a screened, i. with closely juxtaposed Wells equipped surface provided be after the glue loading, for example by immersion or transfer of an adhesive-carrying Roller, being doctored. This will be a special uniform and laterally precisely defined pressure-sensitive adhesive surface reached.

As for the adhesive no subsequent drying before Further processing is necessary, so the usual, thereafter to be provided drying line omitted. The graduation The envelopes in the relay station also do not need to be so tight as it is there because of the gluing and drying is necessary, but it only depends on the speed, with the application roller of the pressure-sensitive adhesive application station 48 can circulate. In any case, the to be coated Stay free. Because of the omission of the drying route It is not absolutely necessary, as with Previous machines otherwise usual, then a special Regulating or aligning provided to the on the Dry stretch slightly shifted from the exact sequence Align envelopes again. By the omission The drying line are also no hold-down in the form of Belts needed to be left for the gaps in the gluing had. This limited the complete gluing over almost the entire width of the envelopes, according to the invention is possible.

In a subsequent extension station 75, which simultaneously the subsequent folding flap folding station 50 will be charged the envelopes 11 again isolated.

Thereafter, the scattered envelopes 11 run in the foldback fold-folding station 50 on. She works according to a scheme which is shown in Fig. 8. The envelope 11 runs with its leading Bodenfalz edge 15 against a on an upper folding roller 51 provided stop 52, the one Alignment function takes over, if necessary. The upper Folding roller 51 and the lower parallel and with opposite Rotation revolving, slightly set back in the conveying direction Faltwalze 53 form a gap 54 between them, through which the envelopes are running. The folding rollers are with selectively controllable depending on its circumferential position Suction slots or openings 55, 56, 57 provided. These Be about not shown conventional controls according to Art connected by rotary valves to a corresponding suction air source. The arriving on a conveyor or conveyor table 88 Envelopes will, at the same time as the start of the Stop 52, from the suction openings 55 to the folding roller 51st sucked in and in the direction of which, at the beginning of the Conveying direction 40 corresponds, taken in the direction of rotation. The suction openings selectively supply the envelope in the direction of rotation free in time for him to be caught by a trap 58 which is from an obliquely upwardly directed catch plate 59 and a pocket bottom forming stop 60th consists. The envelope will be in the area of the stop 60, without Stopping it hard stopped because the suction at the lower, also in the region of the gap 54 in the conveying direction rotating folding roller 53 is activated and the local Suction slots 57, the flap 14 and capture it with take the rotation of the folding roller.

In time, a series of narrow suction holes or Slits 56 activated on the upper folding roller 51 in Edge region of a recess 61 are arranged.

At the adhesive area 23 (above the Release agent portion 22) is a recess 68 in the upper Faltwalze 51 provided, if necessary, a Trennmitteischicht 62nd of polytetrafluoroethylene (PTFE) at its bottom. The fold-back flap 1B is grasped by fold surfaces 69, 70, have the suction openings 56, 56a. The flat 69, 70, the in the range of a to be recognized in detail in Fig. 8, about triangular recess 61 are, are designed so that the Folding flap in its adjacent to the fold line 17 Area at a shallower angle from the suction port 56th is sucked. If then the envelope 11 with the fold line 13 comes close to the folding gap 63 by the rotation of the folding rollers, then the suction air is switched off at the suction slot 56 and for those at the suction gap 56 a, which belongs to the surface 70 turned on. It could also be a simultaneous connection be made. This area is under a larger one Angle opposite the tangent to the folding roller 51 employed. Since the unfolding of the fold-back flap 18 at the high operating speed done very quickly, it can through Dynamic forces buckling or bending and supporting from the suction of the openings 56a, to the surface 70 create. When pulling the envelope from the top ' Faltwalze 51, the fold-back then the surface 69th starting, so to speak, "peeled off" after the vacuum is switched off and possibly actively dismantled. This is when Folding the fold-back flap 18 a harmonious and gentle Transfer to the individual folding positions done. This enables high working speeds with great reliability. A rounding between the surfaces 69, 70 or one total curved surface, this effect could possibly still improve.

When switching off the vacuum, the suction air leading Openings and channels usually over the described Valves or rotary valves vented to relieve the vacuum. To speed up this process may take the passive Be provided with an active ventilation by using the the Ventilation-causing valves Compressed air is given up. This Although already proposed for the rejection of cutting waste been unusual, but at folding rollers, because a active repulsion of the fold-back flap is undesirable. Active ventilation should therefore be limited to a level which causes a quick detachment.

During synchronous further rotation of the folding rollers 51, 53 is the Closure flap 14 at the fold line 13 and the fold-back flap 18 folded at the fold line 17 and the entire envelope in a folding gap 63 between the lower folding roller 53 and a take-off roller 64 pulled. The flap 14th and the fold-back flap 18 are correspondingly to those shown in FIG. Created 3 recognizable points of the envelope, the Pressure-sensitive adhesive area 23 resting on the release agent area 22 applied to the hitherto uncoated folding flap 18 and is pressed. The adhesive transfer from the Separation layer to the fold-back flap causing pressure will either still in the device or even when packaging or applied in the packaging.

The double-line gluing the side flaps over the ever Side flap two parallel glue seams 21 and one extra fast-setting adhesives make for a special safe bonding and also that the glue despite the high conveying speed has already set, if the Envelope reaches the folding station. Thereby and through the in this area three-layered envelope structure (front, Back and side flap) along with the in between lying glue between the bottom fold 15 and the fold line 17th This area is relatively stiff, so that the refolding of Rückfalzklappe along the fold line 17 easily done can. It is mainly avoided by the fact that through the Refolding of the folding flap, the adhesive flow between the Side flaps and the back cover is torn open. Furthermore, it is possible by these two parallel glue lines, a gluing covering a relatively large area without applying so much glue that he pushed out laterally or in the direction of the fold-back flap becomes.

In the subsequent storage station 65 is by means of a Storage drum 66 (fan wheel) the flow of envelopes stored a conveyor 67 and forwarded to the packaging.

According to the type and design of the envelopes can in such a device 30 additional stations for provided the individual to be made or partly also stations exchanged for others or be omitted. Also another succession is possible.

Fig. 6 shows an enlarged partial section, in which before in particular, the material thicknesses to be representable, strong are excessive. The release agent layer 22 is on a primer layer 22 'applied, on the one hand a preparation for the release agent, e.g. by closing the paper pores and on the other hand, an adhesion between paper and release agent can make. This can be demonstrated in the following Fig. 7 described device another applicator in a printing station, depending on the type of primer with or without Drying or hardening device before the release agent application.

Fig. 6 shows finer, that at the Rückfaltklappe 18 a front, to the edge 24th subsequent handle portion 27 'may be provided, outside the Pressure-sensitive adhesive area 23 and from this by a pre-break line 27 "(grooving, Line stamping o. The like.) Is separated. This strip-shaped grip portion 27 'can be light set up with a finger and taken to pull off the folding door 18 and to be able to set up.

The invention thus provides an envelope in an advantageous embodiment, consisting of a front and a back, which have side flaps connected to each other. He has a fold-back flap on which a pressure-sensitive adhesive layer 23 "is applied, and the pressure-sensitive adhesive is applied to the fold-back flap by transfer, i. the pressure-sensitive adhesive is in the manufacture of the release agent layer applied and taken over when erecting the fold-back of this. It is a strong-acting, adhesive adhesive without moistening or other activation is effective. The fold-back flap is used for transport and Storage applied to the Umschlrückückseite, with a release agent coated The area is provided to the redissolution of the pressure-sensitive adhesive before use enable. To close the otherwise uncoated flap pressed on the adhesive-coated fold-back flap.

Claims (20)

1. Envelope having a closure flap (14) joined to an envelope front (12) and a fold-back flap (18) which can be flapped up from a stored state into a closed state and which in the stored state is flapped onto the envelope back (16), with adhesive closure by means of a pressure sensitive adhesive coating (23'), which in the stored state engages on a separating area formed by a surface area of the envelope back, and in which the fold-back flap (18) can in the closed state be adhered to the closure flap (14), characterized in that the pressure sensitive adhesive coating (23'), the surface of a pressure sensitive adhesive area (23) on the fold-back flap (18) and the separating area (22) are constructed in cooperating manner in such a way that the pressure sensitive adhesive coating (23") applied to the separating area (22) has such a limited adhesion with respect to the separating area that its underside admittedly detachably adheres to the separating area (22) during application to the latter carried out during envelope manufacture, but the adhesion between the pressure sensitive adhesive area (23) of the fold-back flap (18) and the pressure sensitive adhesive coating (23") is sufficiently great that the top of the latter adheres firmly to the surface of the pressure sensitive adhesive area (23) pressed onto the top, the previous underside of the pressure sensitive adhesive coating (23") forming the surface of the latter after flapping up the fold-back flap has pressure sensitive adhesive characteristics for sealing by flapping down the closure flap onto the pressure sensitive adhesive coating.
2. Envelope having a closure flap (14) joined to the envelope front (12) and a fold-back flap (18) which can be flapped up from a stored state into a closed state and which in the stored state is flapped onto the envelope back (16), with an adhesive closure by means of a pressure sensitive adhesive coating (23'), which in the stored state engages on a separating area formed by surface areas of the envelope inside, and where the fold-back flap (18) in the closed state can be adhered to the closure flap (14), characterized in that the pressure sensitive adhesive coating (23'), the surface of a pressure sensitive adhesive area (23) on the closure flap (14) and the separating area (22) are constructed in cooperating manner in such a way that the pressure sensitive adhesive coating (23") applied to the separating area (22) has such a limited adhesion with respect to the separating area that its underside admittedly detachably adheres to the separating area during application to the latter carried out during envelope manufacture, but the adhesion between the pressure sensitive adhesive area (23) of the closure flap (14) and the pressure sensitive adhesive coating (23") is sufficiently great for the top of the latter to adhere firmly to the surface of the pressure sensitive adhesive area (23) pressed onto the top, the previous underside of the pressure sensitive adhesive coating (23") forming the surface of the latter after flapping down the closure flap (14) having pressure sensitive adhesive characteristics for sealing the envelope.
3. Envelope according to claim 1, characterized in that the pressure sensitive adhesive coating (23') is provided on the fold-back flap (18) and at least in a separating area (22) on which engages the pressure sensitive adhesive area (23) taken up by the pressure sensitive adhesive coating the envelope back (6) has the surface with the separating characteristics.
4. Envelope according to one of the preceding claims, characterized in that the surface area with the separating characteristics has a separating agent coating, which in particular contains acrylate resins, silicone acrylate, other silicone compounds, etc.
5. Envelope according to one of the preceding claims, characterized in that the separating area has two superimposed coatings, namely a primer coating, which forms a first coating, and a separating agent coating, whose adhesion to the primer coating is better than to the pressure sensitive adhesive coating.
6. Envelope according to one of the preceding claims, characterized in that on its edge adjacent to the outer edge of the fold-back flap (18) the pressure sensitive adhesive area (23) has gripping recesses (27) or a prebreak (27¹¹) defining a gripping zone (27').
7. Envelope according to one of the preceding claims, characterized in that the pressure sensitive adhesive area (23) extends close to the envelope outer edges (20).
8. Envelope according to one of the preceding claims, characterized in that the side flaps (19) linking the front and back (12, 16) of the envelope (11) in each case have parallel glue seams (21), which can optionally be interconnected at at least one end.
9. Method for the manufacture of an envelope, which has a closure flap (14) joined to an envelope front (12) and a fold-back flap (18) which can be flapped up from a stored state into a closed state and which in the stored state is flapped onto the envelope back (16) and having an adhesive closure by means of a pressure sensitive adhesive coating (23') which in the stored state engages with a separating area (22) having separating characteristics formed on surface areas of the envelope, the fold-back flap (18) being adhered in the closed state to the closure flap (14), characterized in that a surface area of the envelope (11) forming a separating area is provided with a separating agent, the latter is dried and/or hardened and that the pressure sensitive adhesive coating (23') is applied to the separating area (22) of the envelope (11) provided with the separating agent and subsequently the envelope fold-back flap (18) is pressed against the pressure sensitive adhesive coating (23') in such a way that in the stored state the pressure sensitive adhesive adheres thereto and as a result of its adhesion characteristics being better than the separating agent can be released following the lifting of the fold-round area from the surface provided with the separating agent and consequently having inferior adhesion characteristics.
10. Method according to claim 9, characterized in that the folding round of the fold-back flap (18) and/or the closure flap (14) takes place by means of controlled suction air support and the termination of the suction action is accelerated by compressed air addition.
11. Method according to one of the claims 9 or 10, characterized in that the pressure sensitive adhesive coating (23') is applied to a flow of successive envelopes in areas spaced from one another in the conveying direction and optionally the flow has a limited or no mutual overlap of the envelopes (11).
12. Apparatus for the manufacture of an envelope in the stored state having a closure flap (14) joined to the envelope front (12) and a fold-back flap (18) which can be flapped up from a stored state into a closed state and which in the stored state is flapped onto the envelope back (16), and which has an adhesive closure by means of a pressure sensitive adhesive coating (23') engaging in the stored state with a separating area (22) having separating characteristics formed on surface areas of the envelope, the apparatus having a storage means (33) for a paper web (31), a shape cutting station (43) for the blank forming the envelope and a folding and adhesive coating station (44) for side flaps, characterized in that the apparatus has a separating agent application station (36) in the manner of a printing mechanism (38) for application purposes and optionally a drying device (39) for drying and/or hardening the separating agent and that in the production direction following the same has a pressure sensitive adhesive coating application station (48) having an application roll with one or more individual, mutually circumferentially spaced application segments with optionally latticed and, following adhesive feed, scraped surface and is provided for placing on a separating area (22) previously provided with the separating agent, and that following onto the same is a folding station (50) for folding the fold-back flap (18) against the envelope back (16) and optionally the closure flap (14).
13. Apparatus according to claim 12, characterized in that the folding station has a folding roll (51) for the fold-back flap (18), which in an area of the envelope (11) provided with the pressure sensitive adhesive (23) has a recess (68) and/or a separating agent surface (62).
14. Apparatus according to claim 13, characterized in that the folding roll (51) has a suction area with suction openings (56, 56a) located in the vicinity of a recess (61) of the folding roll (51) and whose suction faces (69, 70) towards the outer edge (24) of the fold-back flap (18) form a larger angle to the tangent to the folding roll (18).
15. Apparatus according to claim 13 or 14, characterized in that the folding station (50) is connected directly onto an extraction station (75) in which the envelopes (11) are separated and which directly supplies the folding station (50).
16. Apparatus according to one of the claims 12 to 15, characterized in that the application station (36) is positioned following an unwinding location for a material web (31) from which the envelopes (11) are manufactured and optionally with the application station (36) is associated a fixing station (39) for drying and/or hardening the separating agent, particularly using UV lamps.
17. Apparatus according to one of the claims 12 to 16, characterized in that it has a conveyor conveying the envelopes (11) between the separating cutting station (45) and the closure and fold-back flap folding station (50) in the form of an only slightly staggered or unstaggered flow of successive envelopes.
18. Apparatus according to one of the claims 12 to 17, characterized in that the folding station (50) is connected without interposing drying station to the pressure sensitive adhesive application station (48).
19. Apparatus according to one of the claims 12 to 18, characterized in that it has a staggering station (46) with at least one staggering roll (47), which cooperates with the in each case leading edge (15) of each envelope (11) and that said staggering roll (47) is provided on its circumference with stops or steps.
20. Apparatus according to one of the claims 12 to 18, characterized in that the folding roll (51) has an orienting stop (52) for the leading bottom edge (15) of each envelope in conveying direction (40).

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