EP0224631B1 - Envelope, particularly for automatic enveloping - Google Patents

Description

The invention relates to an envelope, in particular for machine inserting, with the features of the preamble of claim 1 and a method for producing the aforementioned envelopes.

The automatic filling of envelopes suitable for inserting machines encounters difficulties in practice, since when filling the filling material the filling material runs into the adhesive seam between the bottom flap and side flaps and gets caught between these two parts of the envelope. This applies particularly to envelopes with internal side flaps.

Methods are proposed for fitting the rubber coating of the side flaps in such a way that they can be bonded absolutely and without interlocking between the side flaps and the bottom flap (cf. DE-A 2 220 206). However, this measure applies to certain processing methods, e.g. limited to those in which paper is pulled from a roll and processed on a one-line machine.

In other known methods, an absolute and interlocking gluing is only possible if one accepts that glue also gets onto the rear surface of the front of the envelope with the risk that the front and bottom flap of the envelope will stick together and the envelope will become unusable.

Gumming is understood to mean any customary application of adhesive for producing the bonded connections.

In the well-known one-line production, the paper is unwound from the roll, then gummed and the gum e.g. Dried over microwave, whereupon the format is cut by a rotary knife and the blank is folded with the rubberized side flaps to the cover. The glue previously applied and dried on the side flaps is then reactivated and the gluing between the bottom flap and the side flaps is carried out while the side flaps are folded under the bottom flap. When processing sheets, the rubber coating must first be carried out separately on a roller punch and the rubber coating dried. The sheet is then punched out and the blanks are stored. The application of glue results in locally different material thicknesses or, in the case of stacking, locally different stacking heights, which lead to the blanks being deformed like a bowl in the stack. This leads to difficulties in storage and stacking. The same applies to the application of the blanks deformed in this way to the sheet machine which further processes the blanks. Pre-gumming in strip form on a gumming machine with subsequent cross-cutting in order to obtain a reusable sheet can lead to waves. Modern and automatically controlled machines can hardly be used for the subsequent punching.

It is an object of the invention to avoid the disadvantages shown and to design an envelope and a method for its production so that the envelope can be produced in a simple and inexpensive manner and an absolutely hook-free adhesive bond between the bottom flap and the side flaps is ensured without that there is a risk that the bottom flap and the front cover stick together.

The above object is achieved by the teaching of claim 1 and with respect to the method by claims 10 and 11.

With the aforementioned training, the otherwise necessary precision when applying the rubber coating is completely dispensed with. Rather, it is consciously accepted or placed on the fact that the rubber coating, which is applied to the side flap and / or the bottom flap, projects beyond the free edge of the side flap at least in the direction of the closure flap or also towards the center of the front, and so a part the rubber coating also reaches the back of the front of the envelope. This ensures that the side flaps are reliably coated with rubber, especially in the critical areas immediately adjacent to the flap edge facing the flap. The effect of the rubber coating on the rear surface of the front of the envelope when applying and / or gluing the bottom flap is rendered harmless by providing a release agent between the rear surface of the front surface and these rubber coating areas, which makes the adhesive force ineffective after the rubber coating has dried that gluing between the front of the envelope and the bottom flap is excluded.

The sub-claims 2 to 5 relate to advantageous developments of the teaching of claim 1.

According to subclaims 2 to 5, the arrangement of the separating layer is provided exclusively in the region of the free edges of the folded side flaps and should extend outside of the side flaps. This makes it possible to use a relatively small amount of the release agent, since it only has to be applied in strips to the rear surface of the front.

The release agents can be based on lacquer, silicone or wax or similar suitable agents.

Compared to claims 1 to 5, the solution according to claims 6 to 8 provides for a full-surface application of the separating layer on the rear surface of the front side and the rear surface of the bottom flap between the edge zones interacting with the side flaps, the separating layers being pigmented, the translucency of the front side and the bottom flap reducing or preventing coatings are formed. As a result, the otherwise necessary printing on the rear surfaces of the front side and the bottom flap can be dispensed with, in order to avoid the risk of the contents of the envelope showing through. In practical tests, separating layers according to claims 7 and 8 have proven their worth. As printing inks for

The dispersions mentioned are suitable for pigment preparations which are dispersible in water and low-volatility, water-miscible organic solvents, so that the previously required use of printing inks with a very volatile solvent for the internal printing of the envelopes can be dispensed with. In this way, a reduction in environmental pollution is achieved at the same time.

Particularly favorable conditions for secure gluing of the side flaps to the bottom flap result if the required amount of the rubber material is applied as a strip to the rear surface of the bottom flap and half as a strip to the respective side flap and the rubber strips on the side and Bottom flap are laterally offset from each other so that they still overlap over part of their width.

The application of the rubber strips to the side flaps and the bottom flap results in a wider zone over which the flaps are glued to one another, with a very secure and resistant bond being achieved in the area of the overlapping of the rubber strips that are offset laterally, but on the other hand in the side sufficient coverage is still present in the overlapping zones so that disruptions in the later handling of the envelope, for example in the automatic distribution in the postal service, are avoided. The areas of the bottom flap and the side flaps lying one on top of the other can be connected sufficiently firmly over a wide zone with a relatively low amount of adhesive. Another advantage results from the fact that when the bottom flap is pressed onto the side flaps, only in the area of the overlapping rubber strips can a correspondingly small amount of adhesive be squeezed out over the edge of the side flap facing the closure flap, which edge gets there on the separating layer and due to the relative small amount dries very quickly there, without it can develop an adhesive effect.

On the other hand, however, in the area of the edges mentioned, which are facing the closure flap, secure gluing of the bottom and side flaps is achieved, which is of crucial importance for the automatic inserting. To produce the new envelope, the invention provides procedures according to claims 10 to 12, wherein claim 10 the manufacture of envelopes according to claims 1 to 5 and 9 and claim 11 the method for the manufacture of envelopes according to claims 1 and 6 to 8 concerns.

The amounts of the gumming material mentioned in process claim 12 have proven to be particularly expedient and, based on experience, also sufficient to achieve a secure bond in the area of the overlapping gumming strips and in the area outside of this overlap to achieve sufficient liability, which also applies to automatic handling of the envelope Sorting machines is preserved.

The manufacture of the envelopes is extremely simple in accordance with the process claims and, because of the reduced precision requirements for the application of the rubber coating, is also inexpensive in relation to the free edges of the side flaps. The described full-surface application of the release agent mixed with color pigments onto the entire rear surface of the front side and the rear surface of the bottom flap in the area between the edge zones interacting with the side flaps eliminates the otherwise necessary printing of the surfaces mentioned, so that a whole operation in the production of such envelopes is omitted is saved. You can use the roll format as well as the sheet or sheet format to manufacture the envelopes.

With the full-surface coating of the rear surfaces of the front and the bottom flap, it is also ensured that glue particles that should get onto the rear surface of the front or the bottom flap cannot lead to an adhesive bond between the front and the bottom flap. In this respect, too, the full-surface coating of the mentioned rear surfaces of the front and the bottom flap with the release agent is advantageous.

• Fig. 1 zeigt einen fertigen Zuschnitt für eine erste Variante des neuen Briefumschlages,
• Fig. 2 gibt entsprechend Fig. 1 eine zweite Variante des fertigen Zuschnittes wieder.

The invention is explained in more detail below with the aid of schematic drawings using two exemplary embodiments.

• 1 shows a finished blank for a first variant of the new envelope,
• FIG. 2 shows a second variant of the finished blank corresponding to FIG. 1.

The envelope according to FIG. 1 has a front side 13, the rear surface of which faces the viewer, and to which the closure flap 5 and the bottom flap 4 are connected via fold lines 6, 7. 3 side flaps 2 continue to connect to the front 13 via fold lines. To finish the envelope, these are folded inwards, provided with glue and glued to the bottom flap 4. In this case, instead of or in addition to the application of glue to the side flaps, the bottom flap can be provided with glue in the area of its contact surfaces on the side flaps.

For a machine-appropriate behavior of the envelope during automatic inserting, it is essential that the side flaps lying inside the envelope, at least in the region of their ends facing the closure flap, are bonded edge-tight to the bottom flap 4, since otherwise the documents to be introduced can get caught between these two parts , which interferes with the automatic inserting process.

This is achieved in a simple manner in the envelope shown in FIG. 1. It does not matter whether the blank shown is made from roll paper or from sheet or sheet paper. According to the example shown, after the side flaps 2 have been folded in, the glue or another adhesive is used to rubberize the screen tenklappen applied to this for example with the help of segments. The application is thus in the form of strips 8.9. The further inside adhesive strip 9 is deliberately applied so that it overlaps the edge 10 of the side flap 2 both in length and in width of the side flap 2. As a result, glue areas 12 also reach the rear surface of the front 13 of the envelope, as shown in the figure. This type of glue application ensures in any case that during the subsequent bonding between the side flaps 2 and the bottom flap 4, the connection is absolutely tight and firm up to the edge 10 of the side flaps 2.

In order to prevent the rear surface of the front side 13 from sticking to the bottom flap 3 due to the protruding glue areas 12, a release agent is applied to the blank before the side flaps 2 are folded in. In the example shown in FIG. 1, this is applied as a release agent strip 11, at least over the height of the rear surface of the front 13 of the envelope. In the example shown, the release agent strip 11 extends into the closure flap 5. The position of the release agent strip 11 is selected so that the edge 10 of the side flap 2 comes to lie approximately centrally on the release agent strip when the side flap is folded. The width of the release agent strip 11 is chosen so that with this relative position the full width of the rubber strip 9 comes to rest securely on the release agent strip 11, as shown at the top right in the area of the leading edge of the side flap 2 at reference number 12.

The release agent strip 11 is expediently chosen to be sufficiently wide to reliably compensate for tolerances in the application of the rubber strip 9 and to ensure that no adhesive gets directly onto the rear surface of the front 13 of the envelope, but only onto the release agent areas. The release agent ensures that after the rubber coating has dried, the adhesive strength of the rubber coating in the area of the release agent becomes ineffective.

In the envelope or blank of FIG. 2, the parts corresponding to FIG. 1 are provided with the same reference numerals.

The envelope or blank shown in FIG. 2 is equipped on the rear surface of the front side 13 with a full-surface release agent coating 11a. The rear surface of the bottom flap 4 also has a full-surface coating 11 b, which extends in the area between the edge zones interacting with the side flaps 2. The release agent layers 11a and 11b, which are applied in one go during production, are designed as a dispersion mixed with a pigment preparation and thus simultaneously represent an internal printing on the front 13 and the bottom flap 4, so that the content of the envelope does not follow shines through to the outside and is therefore not recognizable from the outside, in particular is not legible.

2, the side flaps 2 are shown in dashed lines in the unfolded and in solid lines in their folded position folded over on the rear surface of the front side 13. In the right part of FIG. 2, the side flap 2 is shown with rubber strips 8 and 9 applied, as are also shown in FIG. 1. In the right part of the bottom flap 4 it is indicated by dash-dotted lines that in addition to or instead of the rubber strips 8 and 9 of the side flap 2, two rubber strips 8 'and 9' can be applied.

Another particularly useful arrangement of the rubber strips is shown in the left part of FIG. 2. In this embodiment, a rubber strip 9a, which extends approximately to the free edge 10 of the side flap 2, is shown on the side flap 2 and in this example extends to a little over half the width of the side flap. A second rubber strip 9b is laterally offset on the bottom flap 4 with respect to the rubber strip 9a, in such a way that the two rubber strips 9a and 9b overlap over part of their width. The overlap area 9c is indicated on the side flap 2 by a tight hatching.

The rubber strip 9a, like the rubber strip 9, has an area 12 which extends beyond the side flap 2 onto the rear surface of the front side 13.

It can be seen from the left part of FIG. 2 that the overlap region 9c of the rubber strips 9a and 9b extends beyond the free edge 10 of the side flap facing the closure flap 5, so that a secure and permanent connection of the bottom flap 4 to the side flap 2 is guaranteed in this area, which is of crucial importance for the automatic filling of the envelopes. The areas of the rubber strips 9a and 9b located outside the overlap zone 9c in the folded state of the envelope ensure sufficient adhesion between the bottom flap 4 and the side flaps 2, which do not come loose during later handling, so that such envelopes are also passed through automated sorting systems can.

Instead of letting the rubber strip 9a in FIG. 2 end approximately with the free edge 10 of the side flap 2, this could also protrude above the free edge 10, as is shown in the right part of FIG. 2.

Claims (12)

1. An envelope, more particularly for machine assembly, in which the base flap is adhered with gum to the side flaps which lie inside the envelope, characterised in that for firm adhesion up to the respective free edge (10) of the side flaps (2) the gum (9, 12) overlaps the side flap at least in the direction towards the closure flap (5) and outside the side flap (2) a separating layer (11) is provided between the rear surface of the front side (13) of the envelope (1) and the gum.

2. An envelope according to claim 1, characterised in that the gum (9, 12) is applied to the folded side flaps (2) and/or to the rear surface of the base flap (4) and overlaps the edge (10) of the side flap (2) in both width and length.

3. An envelope according to claim 1 or 2 characterised in that the gum (9, 12) is applied to the side flaps (2) and/or the base flap (4) with the aid of segments in the form of narrow strips (8, 9; 8', 9').

4. An envelope according to any one of the preceding claims, characterised in that a separating layer strip (11) running longitudinally of each side flap is provided, its width exceeding the width of the gum (9, 12), said strip (11) extending substantially over the height of the front side (13).

5. An envelope according to any one of claims 1 to 4, characterised in that a silicone or paint containing separating agent or one synthesized on to a wax base is sprayed on or printed on as a separating layer (11).

6. An envelope according to claim 1, characterised in that there are provided on the rear surface of the front side (13) completely covering it and on the rear surface of the base flap (4) completely covering it in the region between the edge areas cooperating with the side flaps (2) a separating layer (11 a or 11 b), and that the separating layers are formed as pigmented coatings reducing or preventing the translucence of the front side and the base flap.

7. An envelope according to claim 6, characterised in that a polymer dispersion mixed with a printing ink is sprayed or pressed onto the rear surface of the front side (13) and the rear surface of the base flap (4) as the separating layer (11a; 11 b).

8. An envelope according to claim 6, characterised in that a dilute polyethylene primary dispersion mixed with printing ink is sprayed or pressed on to the rear surface of the front side (13) and the rear surface of the base flap (4) as the separating layer (11 a; 11 b).

9. An envelope according to any one of claims 1 to 7, characterised in that the quantity of gum material required for firm adhesion of each side flap (2) to the base flap (4) is applied half as a strip (9b) on to the rear surface of the base flap and the other half as a strip (9a) on to the respective side flap and the gummed strips are laterally offset from one another on the side and base flaps so that they overlap over a part (9c) of their width.

10. A method of manufacturing an envelope suitable for mechanical envelope making in accordance with any one of claims 1 to 5 and 9, in which roll-type starting material is processed along the "one-line" production line or sheet-form or letter-form starting material is used initially and in which after applying gum to the side flaps and/or the base flap the side flaps are adhered to the base flap, characterised in that the gum is so applied to the side flaps after they have been folded round on to the rear surface of the front side of the envelope and/or on to the rear surface of the base flap with the aid of segments in strip shape, that when applying the gum and/or when folding and pressing the base flap a gummed strip overlaps the respective free edge of the side flaps and covers both regions of the side flaps and regions of the rear surface of the front side of the envelope and that before folding the side flaps in the region of the rear surface of the front side, in which the edges of the side flaps come to rest after folding, a separating agent is so applied that it lies, after applying the gum, between the rear surface of the front side of the envelope and the gummed regions located on this rear surface.

11. A method of manufacturing an envelope according to any one of claims 1 and 6 to 8 in accordance with the preamble of claim 10, characterised in that before folding the side flaps the rear surface of the front side of the envelope and the rear surface of the base flap in the region between the edge regions cooperating with the side flaps is coated, more particularly printed completely with a color pigmented polymer or polyethylene primary dispersion, and that gummed strips are so applied to the rear surface of the base flap and/or to the folded side flaps that they extend at least in the direction towards the closure flap up to the adjacent regions of the rear surface of the front side of the envelope when applied to the side flaps and/or when folding and pressing on the base flap over the regions of the free edges of the side flaps.

12. A method of manufacturing an envelope according to any one of claims 10 or 11, characterised in that gummed strips, which are offset laterally from one another but which overlap over a part of their width are applied on the rear surface of the base flap and on the folded side flaps, and that the gum material is applied in a quantity of about 10 g/m² per strip.

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