EP0431144A1 - Process and device for making a product consisting of a base having an adhesive with long-term effect and a protection band attached. - Google Patents

Abstract

The method is intended for manufacturing a product consisting of a support (20) on which there is an adhesive (2-10) with long-lasting effect and a protective tape (15) for a deferred use of said adhesive (2-10 ). It is characterized in that a support (20) is chosen, one face (22) of which receives the adhesive (2-10) has irregularities, and that the adhesive (2) is heated to a temperature at which it is pasty at the limit of the liquid state, then that it is led to at least one orifice (4) opening out above a plane (5) on which the support (20) is placed, then that one causes its flow at the same time as one causes a relative movement between the support (20) and the orifice (4) so that the adhesive (2) is deposited on the support (20) according to au less a thick bead (10), in particular continuous, that the temperature of the adhesive (2) deposited is lowered to increase its viscosity until it is pasty at the limit of the solid state, and that a pressure is exerted on the pasty adhesive (2-10) intended to cause the lateral spreading and the rolling of the bead (10) over its entire length, then optionally at least one subsequent cutting of the product constituted pa r a support (20), a strip of adhesive (10) and a protective tape (15).

Description

 METHOD AND DEVICE FOR MANUFACTURING A PRODUCT

CONSTITUTED BY A MEDIUM ON WHICH ARE

LONG-LASTING ADHESIVE AND PROTECTIVE TAPE

Modern adhesives have reached an excellent degree of efficiency and the trend is towards their generalization as a replacement for other means of assembly.

In the field of cardboard articles, and especially for packaging for example, it is often more advantageous to join two pieces with glue rather than with staples or connecting lugs.

The general problem of fixing with an adhesive can be divided into two families: immediate bonding and deferred bonding.

The present invention essentially relates to this second family which groups all the cases where an adhesive must first be deposited on a part, or "support", then the support coated with adhesive, which should only be used subsequently , sometimes very long after, to bring the first support to a so-called "destination" surface, after all kinds of events have taken place: printing, processing, storage, packaging, transport, delivery, new storage, retail destocking, various manipulations , etc.

The technique of immediate bonding has become relatively simple because, finally, it is now reduced to choosing a kind of adhesives and, if necessary, to adapt the adhesive retained to the problem posed, by adjusting its composition and / or its time. taken, because the two parts are fixed at the same time and there is no longer any need to distinguish an adhesive support and a destination surface.

On the other hand, deferred bonding is infinitely more complex since it is necessary to satisfy very diverse requirements, arising from the existence of three distinct situations instead of just one:

- deposit of adhesive on a given support,

- resistance of the adhesive to aging and to physical-mechanical stresses,

- effectiveness of the same adhesive on the destination surface, even long after the initial deposit on the support.

Here, it is therefore necessary to distinguish two very different operations, although they always involve the same adhesive: adhesion to the support then adhesion to the destination surface, the assembly having to ensure the effective joining of two parts: the support and the surface of destination.

The solutions which currently exist do not give complete satisfaction in all fields of application.

For example, it is quite easy to deposit so-called "self-adhesive" adhesives on supports made of materials having a regular surface and / or of excellent flatness.

This is the case of the paper used for making envelopes, especially because during the deposition of the adhesive paper is placed ^'on a rigid and plane support, such as a steel plate, so that its flexibility translates into adaptability to this support, the characteristics of which it acquires. Finally, if the paper is correctly guided and maintained, it behaves as if it were itself rigid and hard.

This is also the case for materials naturally offering these characteristics: -jQrre, metal, synthetic materials and compact cartons with correctly surface.

Assuming that the adhesive is firmly associated with the support, subsequent bonding to the destination surface is not guaranteed, since the qualities of the adhesive must still be preserved over time and it must find a surface. correct destination.

Here again, the case of paper is relatively simple because being both flexible and thin, the destination surface will be perfectly adapted to the adhesive.

In these favorable cases, the problem to be resolved is therefore to mask the adhesive so that it does not accidentally adhere to other objects and to protect it against dust retention as well as against aging (drying, oxidation, etc. .). The solution adopted consists in placing a tape associated with silicones on the adhesive, which adheres very little to the adhesive. On the other hand, "self-adhesive" adhesives are ill-suited to materials which are not either regular and rigid or, on the contrary, very flexible so that the destination surface matches the support.

A characteristic example of a poorly suited material is corrugated cardboard and it is this which is used here to explain the invention, although the latter has many other applications for various materials.

A sheet of corrugated cardboard essentially has a corrugated face and a so-called "flat" face, although one observes this one with attention one discerns, even with the naked eye, fairly well marked depressions.

In practice, the most frequently encountered sheet of corrugated cardboard has two flat faces placed on either side of a core having corrugations, or grooves. Naturally, depending on the specific resistance desired, it is also possible to give a sheet of corrugated cardboard a more complex structure: two corrugated cores and three flat faces, two outer and one inner separating the two corrugated cores, for example. To simplify the description, we will be satisfied here with the case where the sheet of corrugated cardboard has a corrugated core and two flat faces.

To apply self-adhesive adhesive to such a sheet, a ribbon of thin material is used, impermeable to the adhesive and weakly sensitive to the action of said adhesive. One of the two sides of this tape is coated with adhesive, with the possible use of a treatment allowing the adhesive to "hang" more on one side than on the other. This adhesive-tape set is stored on a reel. When applying the adhesive to the sheet of corrugated cardboard, the coated tape is unwound, an easy operation since the spiral winding has the effect that the adhesive is against the less adhesive side of the tape and there adheres very little.

The tape is applied by its coated side and the adhesive meets a material conducive to its adhesion.

The sheet-adhesive-tape assembly is then stored, transported, distributed, etc. until the actual use of the adhesive which is deferred in time compared to when the adhesive was applied to the tape. Generally, the sheet of corrugated cardboard is a constituent part of a blank intended to form a container.

It is therefore when the container is closed that the adhesive is needed to join the "support" part and the "destination surface" part. To do this, one end of the tape is lifted which detaches more easily from the adhesive than it detaches from the cardboard sheet. Also, can we easily remove the protective tape to release all the adhesive that remains attached to the cardboard sheet ("support") on which it was applied. On its exposed side by removal of the tape, the adhesive must have retained its adhesive power so as to allow by simple contact to fix the cardboard sheet (support) on another part also made of cardboard (destination surface). By thus applying the part carrying the adhesive on a part which does not have one, the two parts are bonded.

But such a coated and treated tape is quite expensive, both for its manufacture and for its installation, so that it is a solution generally discarded when the final product, incorporating the sheet of self-adhesive corrugated cardboard. , must be inexpensive.

Indeed, in addition to the actual constitution of the coated ribbon, the installation of this ribbon supposes that the sheet of corrugated cardboard offers a very regular surface, that is to say devoid of deformation.

However, during the manufacture of a sheet of corrugated cardboard with thin papers, the outer sheets which constitute the so-called "flat" faces of the sheet are applied and bonded directly to the corrugated core and despite all the precautions that one can take (tension of the sheet, guidance, control of the laying speed, quality of the adhesive, etc.) there are depressions of the outer sheets between the tops of two neighboring undulations.

These depressions are sometimes invisible to the naked eye and are barely sensitive to the touch.

This characteristic of this type of corrugated cardboard is well known to those skilled in the art since the determination of the thickness of a sheet of corrugated cardboard cannot be done with a simple device: it is necessary that the parts in contact with the two faces of the sheet whose thickness is to be measured have a relatively large area in order to compensate for the irregularities which are discussed here.

For example, the French standard NF Q 03-030 specifies that the parts of the device ("keys") in contact with the sheet must have ten square centimeters (10 cm2) each. In "LE COLLAGE INDUSTRIEL" by Philippe Cognard and Françoise Pardos, Editions L'Usine Nouvelle, Paris, page 12, it says:

"ACTUAL CONTACT SURFACE

The contact between the two surfaces of two solids is made only in a few points, if one places oneself from the microscopic point of view. If we assume the case of a liquid wetting a solid, there will be microscopic air bubbles which will prevent contact. So in these two cases, the real contact is lower than the proposed contact and the real resistance will therefore be much lower than the maximum theoretical resistance. SURFACE FAULTS

For an equal contact surface, an actual surface will provide a value of the adhesion force lower than that which an ideal regular surface would provide. This results from

The existence of many defects in real surfaces. "

To make a sheet of corrugated cardboard self-adhesive, it is above all necessary that it has a surface as regular as possible and that the tape used is itself of very good quality, these factors being incompatible with a low cost price. .

However, even with sheets of corrugated cardboard made with thick papers, one does not always achieve a satisfactory result. Up to now, better results have been obtained by using tapes comprising a central strip coated with an adhesive on both sides and made of a material on which the adhesive hangs vigorously. On one of the coated faces, a protective tape is placed which is weakly sensitive to the action of the adhesive and, therefore, capable of being easily removed. It is generally a ribbon made of paper or synthetic material associated with symbols. The entire central strip, the two layers of adhesive and the protective tape is wound up to be stored in reels.

To make an object (a box, for example) self-adhesive, we unwind a certain length of tape with or without a central strip, we apply the coated side to the object ("support") and we cut the unwound segment the length which corresponds to the dimension of the object already shaped.

When the tape is of the type comprising a central strip, the latter is thus fixed once and for all on the support and the adhesive applied will never be used again or even unmasked.

The support-central strip-adhesive-protective tape assembly is then stored, transported, distributed until the user has to use the adhesive, for example to close an envelope, by sticking a flap (support) on the envelope itself (destination surface) or to close a container of any other type.

For this, the user must remove the protective tape in order to unmask the adhesive located outside the central strip. Then, he applies the sheet (support) on another (destination surface) by applying the visible adhesive. Such an expensive and very elaborate tape improves the results and compensates by its high qualities the mediocrity of the flatness of the sheets of corrugated cardboard.

However, better results require the use of very thick papers to constitute the corrugated cardboard, so that the fixing of the support to the destination surface by the adhesive is correct.

It is therefore necessary to give up the best designed products from the cost point of view, which is unfortunate for consumers because either they have high-performance but very expensive products or else cheap but mediocre products. The present invention overcomes all the drawbacks mentioned above and makes it possible to obtain supports: sheets or panels of any material, provided with a long-acting adhesive for a deferred use of this adhesive and, what, whether the quality of the supports, the regularity or the irregularity of the surfaces present, the fineness or the thickness of the materials used.

To this end, the subject of the invention is a method for manufacturing a product consisting of a support on which there is a long-acting adhesive and a protective tape for deferred use of said adhesive, characterized in that the we choose a support with one side to receive the adhesive has irregularities, we heat the adhesive to a temperature at which it is pasty at the limit of the liquid state, then we lead it to at least one orifice opening above a plane on which the support is placed, and then causing it to flow at the same time as causing a relative movement between the support and the orifice so that the adhesive is deposited on the support according to at least one thick bead, in particular continuous, that the temperature of the deposited adhesive is lowered to increase its viscosity until it is pasty at the limit of the solid state, and that a pressure is exerted on the pasty adhesive inée to cause the lateral spreading and the rolling of the cord over its entire length, then that it is optionally carried out at least a subsequent cutting of the product consisting of a support, a strip of adhesive and a protective tape. According to other characteristics of this process:

- The product is intended to be shaped after placement of the adhesive and protective tape, to form a finished article, ready for use by using the adhesive discovered by removing the protective tape; the support being made of a relatively rigid material, it is subjected to a pressure force located in the area where the adhesive must flow, in order to obtain a softening of the support which, in this area, thus becomes more flexible than at 1 Origin; - the pressure force concerns a strip whose width is greater than that of the adhesive after spreading;

the pressure force is calibrated to be greater than the elastic resistance of the material forming the support; - the support material having an internal honeycomb structure, as is the case of corrugated cardboard whose grooves create longitudinal cells, the pressure force is calibrated to be able to break the walls of the cells forming spacers between two opposite faces of the support, but insufficient to remove any elasticity perpendicular to said faces;

- the process being implemented in a room at room temperature, the temperature of the adhesive is lowered by simple absence of heating and by causing the relative movement at a speed such that the time which elapses between the adhesive and its spreading by pressure corresponds to the desired temperature reduction;

- the process being implemented in a room at ambient temperature, and the relative movement having a given speed, a pressure is exerted on the adhesive at a distance from the flow orifice such that the time which elapses between the deposition of the adhesive and its spreading by pressure corresponds to the desired temperature reduction;

- After deposition, the adhesive bead is subjected to positive cooling means, such as a flow of cold air; the support is made of cardboard or similar material, a strip of thin material, impermeable to the adhesive and weakly sensitive to the action of said adhesive, is placed on the adhesive bead previously deposited on the support, and in order to spread the bead of adhesive on the support, pressure is exerted on the tape; - the support is made of cardboard or similar material wound over a great length in the form of a coil, at least one bead of longitudinal adhesive is deposited at the same time as the support is unrolled, a ribbon of thin material is placed on the bead , impermeable to the adhesive and weakly sensitive to the action of said adhesive, in order to spread the bead of adhesive on the support, pressure is exerted on the ribbon and this assembly is wound up on a spool for storage;

- the support is made of cardboard or similar material wound over a great length in the form of a coil, at least one bead of longitudinal adhesive is deposited at the same time as the support is unrolled, a ribbon of thin material is placed on the bead , impermeable to the adhesive and weakly sensitive to the action of said adhesive, in order to spread the bead of adhesive on the support, pressure is exerted on the tape, this assembly is wound up on a reel for storage, then , before using the adhesive, the support is cut into panels intended to constitute blanks, in particular for obtaining containers;

the support is a panel of cardboard or similar material, at least one bead is deposited on said panel with a first edge which the latter has at a second edge opposite to the previous one, a ribbon of thin material is placed on the cord, impermeable to the adhesive and weakly sensitive to the action of said adhesive, in order to spread the bead of adhesive on the support, pressure is exerted on the tape then, optionally, imperfect margins are eliminated. the support is a panel of cardboard or similar material, several panels are brought in one after the other, leaving a space between them, at least one bead is deposited on each panel with a first edge which they present to a second edge opposite the previous one, a ribbon of thin material is applied to the cord, impermeable to the adhesive and slightly sensitive to the action of said adhesive, a ribbon which is continuous and which extends from one panel to another. above the space which separates them and, in order to spread the bead of adhesive on each panel, pressure is exerted on the ribbon directly above each panel, then a ribbon is cut between the panels;

- the cut is made against the two opposite edges of each panel;

- the cut is made between the two edges opposite two neighboring panels; - the cut leaves at least one segment of ribbon remaining beyond at least one of the edges of each panel;

- the support is made of cardboard or similar material, a ribbon of thin material is applied to the bead of adhesive deposited, impermeable to the adhesive and slightly sensitive to the action of said adhesive, in order to spread the bead of adhesive over the support, pressure is exerted on the tape, the quantity of adhesive deposited and the value of the pressure exerted on the tape being coordinated so that after spreading the bead, the width that the adhesive occupies on the support is at most equal to that of said ribbon;

- The support is made of cardboard or similar material, a ribbon of thin material is applied to the bead of adhesive deposited, impermeable to the adhesive and slightly sensitive to the action of said adhesive and the bead is spread only when the temperature to which it has dropped after being deposited on the support has sufficiently increased its viscosity so that its degree of adhesion to the ribbon of thin material is significantly lower than the degree of adhesion that it has with the support;

- the support is made of cardboard or similar material, the adhesive is caused to flow through an orifice which has a section and an orientation such that the adhesive bead deposited by flow has a substantially circular section, the tape is laid in thin material at a certain distance from said orifice by coordinating this distance, the temperature at which the adhesive is deposited on the support and the speed of the relative displacement, so that the bead of adhesive sags a little laterally, then we place on the adhesive bead a ribbon of thin material, impermeable to the adhesive and weakly sensitive to the action of said adhesive and in order to spread the adhesive bead on the support, pressure is exerted on the ribbon;

the support is made of cardboard or similar material, at least one bead of adhesive is deposited, a ribbon of thin material is applied thereon, impermeable to the adhesive and weakly sensitive to the action of said adhesive, in order to spread the bead of adhesive on the support, apply pressure to the tape, deposit and laminate at least one bead of adhesive in sufficient quantity so that the bead, after spreading, fills all said irregularities and furthermore provides the ribbon of thin material with a flat and continuous surface;

- The support is made of cardboard or similar deformable material, the support is leveled at least according to the area to receive said adhesive, at least one bead of adhesive is applied, a ribbon of thin material, impermeable to water, is placed on it adhesive and weakly sensitive to the action of said adhesive and in order to spread the bead of adhesive on the support, pressure is exerted on the tape;

the support is made of cardboard or similar deformable material, a regular recess is produced over the entire area which is to receive said adhesive, at least one bead of adhesive is deposited in said recess, a ribbon of thin, impermeable material is placed on said bead to the adhesive and weakly sensitive to the action of said adhesive, in order to spread the bead of adhesive in the hollow of the support, pressure is exerted on the tape, the depth of said hollow being substantially equal to the total thickness of l spread adhesive tape and thin material; - The adhesive is heated, it is circulated in a closed circuit conduit and the said flow is caused by removing a fraction of adhesive circulating in the closed circuit conduit;

- the adhesive is heated, it is circulated in a closed circuit conduit, the adhesive which circulates in the closed circuit is maintained substantially at the temperature which it must have for its flow and one causes said flow by removing a fraction of adhesive flowing in the closed circuit conduit; -the adhesive is heated, it is circulated in a closed-circuit duct, a fraction of adhesive circulating in the closed-circuit duct is taken, the temperature of the adhesive fraction removed is increased and then provoked the flow of said fraction.

The invention also relates to a device for manufacturing a product consisting of a support on which there is a long-acting adhesive and a protective tape, for a deferred use of said adhesive, characterized in that it comprises a frame, guides for at least one support intended to receive adhesive, at least one adhesive reservoir, means for heating said adhesive in the reservoir, at least a conduit extending from the reservoir to at least one orifice, means for closing and opening the conduit close to the orifice as well as means for controlling said means for closing and opening, means for setting in relative motion of said orifice and at least one support intended to receive adhesive, means capable of exerting pressure and rolling in a direction substantially perpendicular to a plane in which the support intended to receive must be located adhesive and means for removing supports after receiving adhesive.

According to other characteristics of this device: - it is located in a room at room temperature and that the means capable of exerting pressure and rolling are distant from 1 orifice;

- It includes positive cooling means located between the orifice and the means capable of exerting pressure and rolling;

- It comprises means for storing at least one support made of cardboard or similar material, means for storing at least one strip of thin material, impermeable to the adhesive and weakly sensitive to the action of said adhesive, means for depositing adhesive, means for guiding said tape over adhesive deposited on the support, means for simultaneously pressing the tape on the adhesive and adhesive on the support as well as means for discharging in storage view of the support-adhesive-tape assembly;

- It comprises means for supporting at least one support coil of cardboard or similar material, means for depositing adhesive, means for unrolling the support and making it pass opposite at least one flow orifice d adhesive, means for storing at least one ribbon of thin material, impermeable to the adhesive and weakly sensitive to the action of said adhesive, means for guiding said ribbon over the adhesive deposited on the support, means for simultaneously pressing the tape on the adhesive and the adhesive on the support, means for winding the support-tape adhesive assembly according to at least one reel and means for supporting said reel; - It comprises means for storing at least one stack of panels of cardboard or similar material, means for removing and distributing said panels one by one, means for guiding said panels, means for unitary movement of said panels in view of their running opposite at least one adhesive flow orifice, means; for depositing adhesive with a first edge that each panel has at a second edge opposite to the first, means for storing at least one strip of thin material, impermeable to the adhesive and weakly sensitive to the action of said adhesive, means for guiding said strip over the adhesive deposited on each panel, means for simultaneously pressing the strip on the adhesive and adhesive on each panel, means for cutting said tape, means for removing the panel-adhesive-tape assembly and means for depositing each of said assemblies one on the other to constitute at least a battery;

- It comprises means for storing at least one stack of panels of cardboard or similar material, means for removing and distributing said panels one by one, means for guiding said panels, means for unitary movement of said panels in view of their running opposite at least one adhesive flow orifice, means for depositing adhesive from a first edge that each panel has at a second edge opposite to the first, means for storing at least less a ribbon of thin material, impermeable to the adhesive and weakly sensitive to the action of said adhesive, means for guiding said ribbon over the adhesive deposited on each panel, means for simultaneously pressing the ribbon on the adhesive and adhesive on each panel, means for simultaneously cutting said tape and a small fraction of the panel near the first and second edges of each panel, means for discharging the cut fractions, means for discharging the panel-adhesive-tape assembly and means for depositing each of said assemblies one on the other to constitute at least one pile;

- It comprises at least one orifice situated above a plane on which there must be a support so that the adhesive which has to flow through said orifice falls vertically onto the support;

- It comprises at least one orifice with a circular horizontal section and located above a plane on which there must be a support so that the adhesive which has to flow through said orifice falls vertically onto the support in a circular section;

- It includes a frame, guides for at least one support intended to receive adhesive, at least one adhesive reservoir. means for heating said adhesive in the reservoir, at least one conduit extending in a closed circuit to and from said reservoir, a branch in heat-conducting material, which is connected to said conduit, which ends in an orifice and which comprises sealing and opening means, heating members being placed outside said branch, the device further comprising means for regulating the heating means of the tank and heating members of the branch.

The invention will be better understood from the detailed description below made with reference to the accompanying drawing. Of course, the description and the drawing are given only by way of an indicative and nonlimiting example. Figure 1 is a schematic view of a device according to the invention, applied to obtaining sheets of great length having at least one line of adhesive.

Figure 2 is a schematic view of a device according to the invention, applied to obtaining panels, or plates, having at least one line of adhesive.

Figures 3 and 4 are two schematic views illustrating a phase of the process according to one invention and providing a preparation of the support before the introduction of the adhesive. Figure 5 is a schematic view in longitudinal section showing the phase of the process according to the invention which corresponds to the combination of a support, the adhesive and a protective tape.

Figure 6 is a schematic cross-sectional view showing the phase of the process according to the invention which corresponds to the deposition of the adhesive on a support.

Figure 7 is a schematic cross-sectional view showing the phase of the process according to the invention which corresponds to the deposition of the protective tape on the adhesive. Figure 8 is a schematic cross-sectional view showing the phase of the process according to the invention which corresponds to the combination of the support, the adhesive and the protective tape.

Figures 9 and 10 are partial schematic views illustrating a possibility that gives the method according to the invention for finishing a support having at least one line of adhesive.

Figures 11 and 12 are schematic sectional views showing the manner in which the adhesive is associated with a corrugated cardboard support of irregular surface, using the method according to the invention.

FIG. 13 is a partial schematic view illustrating a variant of the method according to the invention according to which the adhesive and the protective tape are deposited in a groove whose depth is equal to the thickness of the adhesive and of the tape. protection.

Figure 14 is a schematic view in longitudinal section of a machine according to the invention and allowing the industrial implementation of the method of the invention.

Figure 15 is a partial schematic view illustrating the implementation of the method according to the invention for obtaining a correct adhesive bead on supports formed by separate panels, or plates.

Figures 16, 17 and 18 are schematic views illustrating the possibility offered by the invention to obtain continuous or discontinuous adhesive tapes. Figure 19 is a schematic view illustrating a variant of the invention according to which the supports are separate panels while the protective tape is continuous.

Referring to the drawing, it is seen how the implementation of the method according to the invention is carried out.

First, in a heated and insulated tank 1, a certain amount of adhesive 2 is heated to about 175 degrees Celsius to bring it to a consistency according to which it is still pasty but at the limit of liquid state. By a conduit 3, the adhesive is brought to an orifice 4 opening above a fixed plane 5 on which a support is placed.

In Figure 1, there is shown the case where the support consists of corrugated cardboard 6 stored in a reel 7. The corrugated cardboard 6 is guided to extend on the plane 5 and to be moved by traction (as is known per se) parallel to this. Passing vertically from the orifice 4, the corrugated cardboard 6 receives adhesive 2 which flows at a regulated rate so that it is deposited according to a thick bead 10.

After deposition, the temperature of the bead adhesive 10 must be lowered so that its viscosity increases until its consistency is pasty, at the limit of the solid state.

This is a cardboard called "single face", that is to say that it has a corrugated core associated on one of its faces with a single sheet forming a face called "plane". Here, it is assumed that the room in which the method is implemented is at room temperature and the lowering of temperature is obtained by simple absence of heating by adjusting the speed of movement of the corrugated board 6 relative to the fixed support. 5.

When the bead 10 has acquired the desired consistency, a pressure is exerted on it intended to cause its lateral spreading (perpendicular to the direction of its movement) and its rolling over its entire length (parallel to the direction of its movement). This pressure is provided by a roller 11 associated with a jack 12 which urges it along the arrow F1 in the direction of the fixed support 5.

Thus, the cord 10 is crushed so as to finally have only a fairly small thickness compared to that which it presented before being subjected to the pressure of the roller 11, controlled by the jack 12.

The corrugated board 6 - adhesive 2 assembly is then wound in a spiral to form a coil 13. This constitutes a product according to the invention.

This product being a reel of corrugated cardboard provided with a bead of adhesive 10, is a semi-finished product which can be shaped in any desired manner: printing, cutting, creasing, folding, volume setting, etc. The adhesive can be used during this shaping or later, for example for closing the finished article if it is a container (box, box, case, envelope, etc.).

L " ¹ adhesive 2-10 is, of course, always active since it is intended to be used later but it must be isolated from the outside so that it is protected from dirt and to avoid that the cardboard thus coated accidentally sticks to other objects. For this purpose, a protective tape 15 is provided which is unwound from a reel 16 and which is guided over the bead of adhesive 10 just before it is pressed by the roller 11. Thus, the adhesive tape 10 is no longer crushed directly but with the interposition of the protective tape 15.

To obtain the desired temperature, and therefore also the desired viscosity, one must take into account not only the speed of movement of the corrugated cardboard 6 but also the distance X measured between the orifice 4 and the axis of the roller 11. The more the speed is great, the greater the distance X must be.

To combine a high speed of movement and a small distance X, the bead of adhesive 10 can be subjected to positive cooling means (not shown) such as a flow of cold air or a cooling tunnel. In FIG. 2, a variant is shown according to which the support is no longer continuous over a great length but consists of successive individual panels.

The same elements as those in FIG. 1 have the same references. The operations which are common to the two variants will not be described since they have already been explained.

The panels 20 are, for example, of "double-sided" corrugated cardboard, that is to say that they come from cutting from a sheet of corrugated cardboard comprising a corrugated core and a sheet on each of its two faces, to present two so-called flat faces.

It is in a material of this kind that containers of low price are generally created, in particular for shipments by post or by courier.

The panels 20 are stored in a stack from which they are extracted one by one to be individually driven under the orifice 4 and then under the pressure roller 11.

It is good to cause the flow of adhesive 2 through the orifice 4 as soon as the downstream edge of each panel 20 comes into line with said orifice 4 and to interrupt the jet of adhesive 2 coming out of the orifice 4 as soon as the upstream edge of each panel 20 reaches directly above said orifice 4. the words "upstream" and "downstream" must be interpreted by considering the direction in which the panels 20 move relative to the fixed support 5.

If the adhesive 2 flowed continuously, it would deposit not only on the panels 20 but also on the support 5 which is unmasked between the panels 20.

Each panel 20 being individualized, provision is made here for the protective tape 15 to be interrupted between two successive panels 20 by a cut made as close as possible to the downstream and upstream edges of each panel 20.

It is this solution which appears in FIG. 2, where the panels 20 have been voluntarily shown in several positions and in such a way that the roller 11 is released. It can thus be seen that the downstream edge of the panel 20 which is located under the coil 16 receives one end of the ribbon 15 which has been cut at the upstream edge of the panel 20 appearing partially to the left of the roller 11. The ends of the start and end of the bead 10, near the downstream and upstream edges of the panels 20, can then be less regular than its central area.

We will explain below how to eliminate these irregularities. As explained above, the essential problem of a delayed use adhesive results from the fact that the destination surface is often different from the surface of the support. However, in order to join the support and the destination surface, the adhesive must necessarily be as effective for one as for the other.

We have just shown how one can apply a well anchored adhesive to a support, in spite of surface irregularities of this support.

We will now describe means making it possible to ensure that the adhesive thus placed will be effectively fixed, later, on a destination surface in order to durably join the support and the destination surface.

It should be remembered that the present invention makes it possible to solve the most difficult problem in this field, namely that which involves a support and a destination surface having surface irregularities.

This recalled, it should also be emphasized that an important factor to be taken into account is the adaptability to one another of the support and of the destination surface. Thus, for example, it has been found that this problem is even more difficult to solve with a higher quality corrugated article because the more the quality of the corrugated cardboard increases, the more rigid it is.

But rigidity does not mean that the irregularities have disappeared. The product, on the contrary, presents increased defects: irregularities are always present and, in addition, the support and the destination surface are unable to adapt to each other.

We can better understand this phenomenon if we compare, by exaggeration, corrugated cardboard to a corrugated sheet, because we can easily imagine that it would be impossible to glue two corrugated sheets whose corrugations would not be strictly nested: the contact surfaces would minimal and all the weaker as neither of the two sheets would be able to match the undulations of the other by deformation of its own.

We understand, conversely, that if at least one of the sheets was deformable, for example if it was made of rubber, or else if a deformable seal was inserted between them, the "custom-made" contact surfaces would be increased "and one would finally ensure a correct junction, whatever the orientation of the sheets between them (parallel or more or less crossed corrugations) and whatever the transverse shift of the supposedly parallel corrugations.

Now transposing these explanations to the more subtle case of a support and a destination surface having surface irregularities, we understand that the more rigid the elements present, the lower the probabilities of a correct bonding, even if it has been ensured that the adhesive is correctly anchored on the support, when the adhesive is placed in the factory.

When, despite this, a rigid support and destination surface are chosen, the invention provides for reducing this rigidity in the area where the adhesive is to be applied.

FIG. 3 shows a section of a corrugated cardboard support 30 assumed to be of high quality: the paper of which it is made is of the long fiber type and of heavy weight. H has a core 31 of corrugated paper, glued to two opposite external faces 32 and 33.

The parts 34 of the core 31 which extend between the faces 32 and 33 determine longitudinal cells, or channels, 35 and constitute as many spacers which give the support 30 a large rigidity and high resistance to crushing, that is to say that, finally, the faces 32 and 33 are very slightly deformable and that their surface irregularities: hollows 36 and bumps 37 are definitively formed. To apply a face 33 against a face 32 to glue them is, to the nearest scale, to try to glue two corrugated sheets.

According to the invention, the support 30 is prepared for bonding to a destination surface, even before the product is completely produced. For this, we use a pressure means such as a roller

38 rotatably mounted on an axis 39 and biased in a direction perpendicular to the planes of the faces 32 and 33, in order to break the parts 34 forming spacers, without however eliminating any elasticity, on the contrary, between the two opposite faces 32 and 33; We see in Figure 4 that the parts 34 are deformed and have folds 34éi_ thanks to which the support 30 becomes elastic instead of being rigid. It is at the base of this elastic zone that we will deposit the adhesive.

Furthermore, to ensure bonding when using the adhesive 10, pressure is exerted (generally by hand) on the face opposite to that which carries the adhesive 10: if the latter has been applied to a face 32, the opposite face 33 will be pressed. If the support 30 is very rigid, the effort is insufficient to deform the face 32. With a support 30 of the type of that of FIG. 4, the pressure of the hand exerted on one side will be transmitted to the opposite side, allowing the latter to deform and, consequently, to match the irregularities of the destination surface.

Note that the force of the roller 38 slows the movement of the supports 30. To avoid any irregularity of movement, it is good to provide a positive drive of the supports, for example by means of bands or pebble rollers.

However, according to the invention, it is also possible to use the roller 38 itself and, for this, provide for its positive drive by means of a geared motor of known type (not shown) and ensure that its surface in contact with the supports 30 is rough, in particular by knurling, as is known per se.

The flexibility of the support 30, coming from the folds 34a_, is obviously only useful at the level of the adhesive 10, so that if we consider the formation of the folds 34a_ as a weakening, it is only of interest the area where the adhesive 10 is located and, consequently, does not in any way harm the overall mechanical strength of the support 30.

But it is good that the softening of the support 30 created by the roller 38 extend in a strip a little wider than that which the adhesive 10 will occupy when it is deposited and spread, in order to be assured that the pressure of the hand exerted on the opposite side is largely transmitted to all the adhesive.

Figure 5 on the one hand and Figures 6 to 8 on the other hand are schematic views on a larger scale than the previous ones, allowing to highlight the characteristics of the invention.

While the bead 10 travels the distance X, it cools and freezes and the heating of the adhesive 2 is adjusted so that at the outlet of the orifice 4, it has a consistency such that it deforms sagging.

The orifice 4 has a circular section so that the cord 10, when it is deposited, itself has a circular section (Figure 6).

But as it meets the support, it cannot physically keep this theoretical section and it flattens naturally. By moving away from the orifice 4, the cord 10 therefore becomes wider and less high (FIG. 5 and FIG. 7).

When the bead 10 is flattened (FIGS. 8 and 9), it offers a non-negligible surface to the protective tape 15 and since the adhesive 2 is chosen for its prolonged effect, sufficient adhesion is obtained between the bead 10 and the tape 15 to avoid any slipping between them. This arrangement is important because it allows fairly high running speeds despite the resistance offered by the ribbon 15 wound according to the spool 16, when a traction is exerted on it. After the action of the roller 11, the tape 15 is on the adhesive 2 which no longer has the shape of a thick bead but has become a thinner and wider strip (FIG. 8).

The quantity of adhesive 2 delivered by the orifice 4 is established so that after the pressure action of the roller 11, the adhesive strip 10 has a width at most equal to that of the protective tape 15.

The support 20 of Figures 2, 5, 9 and 10 comprises a corrugated core 21 as well as two faces said to be flat 22 and 23. The reference 24 denotes the downstream edge of the panel 20 and the reference 25 its upstream edge.

It can be seen in FIG. 5 that the strip of adhesive 10 as well as the protective tape 15 are practically aligned with the downstream edge 24.

On the other hand, in FIG. 9, it can be seen that the strip of adhesive 10 has an irregular width, coming from the casting of adhesive 2 out of the orifice 4, a casting which cannot immediately provide the desired width, unlike what is obtained, according to the known technique, with orifices located in contact with the support to be coated and whose very thin section delivers the adhesive in its almost final form of coating layer. These holes are known as "lip nozzles".

The same irregularity phenomenon occurs in the vicinity of the upstream edge 25, when the flow of adhesive 2 is interrupted.

In FIG. 5, it can be seen that the casting time is adjusted so that the bead 10 is interrupted a little below the upstream edge 25 because the lamination effected by the roller 11 tends to extend the strip of adhesive longitudinally in the last millimeters of the panel 20 and this must be taken into account so that the adhesive is not spilled out of the panel 20. If the protective tape 15 has the same width as the adhesive strip 10, the provisions of FIG. 9 (in the vicinity of the two downstream edges 24 and upstream 25) can be accepted because the absence of gluing of the protective tape 15 allows you to easily grasp it by its end when you want to remove it, for the application of the support on the destination surface.

However, by suitably adjusting the degree of adhesion of the tape 15 and of the adhesive 10, it is easy to remove the tape 15 without it being necessary to provide these unattractive arrangements.

They are even less useful when the protective tape 15 is wider than the adhesive strip 10, as shown in FIG. 9.

This is why, when the panels 20 are intended to be cut later, an imperfect margin is removed, according to a characteristic of the invention, so that only the central zone of the strip of adhesive 10 having the desired width remains.

For this, the support 20 is cut along lines 26 and 27. FIG. 9 shows the outline of the cutting line 26 to show that it passes as close as possible to the imperfect end of the strip of adhesive 10.

FIG. 10 shows the two oblique and symmetrical cut lines 26 and 27 which give the panel 20 a very attractive quality of appearance and finish.

In certain cases, it turns out to be necessary to finish the panels 20 by removing a more or less wide selvedge, all along their two downstream 24 and upstream edges 25. This advantage is then used to remove the imperfect margins . In this case, obviously, the lines 26 and 27 can no longer be oblique but located in the extension of the downstream 24 and upstream 25 edges.

It is good to carefully adjust the pressure force exerted by the roller 11 in order to obtain not only a crushing of the adhesive bead 10 but also a rolling effect, that is to say that the roller 11 does not follow the irregularities of the support and, on the contrary, remains at a constant distance from the nominal level of the plane 5.

In this way, it is ensured that the upper face of the strip of adhesive 10 will be both continuous and flat. This is illustrated by FIGS. 11 and 12. FIG. 11 shows a panel 20 on which a strip of adhesive 10 has been deposited, as indicated above, transversely with respect to the corrugations of the core 21. It can be seen that the faces external 22 and 23 are not absolutely flat but have depressions opposite the concave parts of the core 21. These irregularities are sometimes difficult to perceive with the naked eye but they are sufficient to make it practically impossible to apply adhesive directly economically on cardboard.

Tests have shown that the application of adhesive to such a support, using the method according to the invention, provides an adhesion surface greater than that which can be obtained with a "lip nozzle" of known type. , applying the same amount of adhesive. The reason is that with a "lip nozzle" the adhesive is deposited everywhere on the support but that, when fixing it on the destination surface, only the tops of the irregularities, that is to say -to say the parts located opposite the convex undulations, make contact. This result cannot be satisfactory because the aim is not only to deposit adhesive on a support. It is above all to allow this adhesive to reunite, subsequently, the support and the destination surface in a rapid, robust and long-lasting manner. However, the probabilities are high so that the concave irregularities of the support are precisely opposite concave irregularities of the destination surface and the adhesive fragments opposite concave irregularities. The bonding is then uncertain. It is uncertain when the attachment takes only a few hours and the assembled parts detach from each other because the adhesion surface provides a lower resistance to the stresses and stresses which stress the assembled parts.

According to the invention, the adhesive fills the concave irregularities and also covers the convex irregularities with a significant thickness for the subsequent fixing of the support on the destination surface, whatever the irregularities of the latter since the adhesive has a surface to both continuous and piane.

In FIG. 11, it can be seen that the strip of adhesive 10 has a thickness E opposite the concave irregularities and another thickness e_ opposite the convex irregularities. Its outer face 1θ is flat and continuous.

FIG. 12 shows the same characteristics in the case where the strip of adhesive 10 is parallel to the corrugations of the core 21 and no longer perpendicular.

The negative effects of an insufficient adhesive can only be combated, according to the state of the art, by improving the condition of the surfaces present, in particular by choosing thick, long-fiber and high-cost papers. The invention overcomes this drawback since it allows the choice of thin and inexpensive papers.

In this regard, it is known that the panels 20 often have faces 22 and 23 of different qualities. For reasons of rationalization, we choose a good quality paper, with long fibers, for the side intended to be outside the finished cardboard object (a container, for example) while for the side intended for to be inside, and therefore not visible, we choose a more ordinary paper, with short fibers, such as recycled paper. The adhesive 2 must precisely be deposited on the ordinary inner face (support), which is intended to be fixed on the outer face of better quality (destination surface).

Thanks to the invention, it is therefore possible to adopt the usual methods for choosing the qualities, without fear of defective bonding. The extra thickness created by a strip of adhesive 10 and its protective tape 15 located asymmetrically, has drawbacks for the storage on a reel 12 of the corrugated cardboard 6 (FIG. 1) or for the storage in a stack of the panels 20. Or else the coil 13 becomes frustoconical instead of being cylindrical, or the panels 20 are placed askew instead of being flat.

To avoid this drawback, the invention provides first of all to create a hollow over the entire location of the adhesive strip 10, at a depth equal to the total thickness of the adhesive strip 10 and the protective tape. 15.

This operation is easy to perform when the support is made of corrugated cardboard because it is a fairly soft material which deforms well.

It is described below with the embodiment of the invention according to which the support is a panel 20.

This hollow, or groove, 28 is formed upstream of the orifice 4 and can be obtained by means of a roller 14 driven in rotation and subjected to a pressure force directed perpendicular to the face.

22 of the panel 20, in order to obtain a deflection of the corrugations of the core 21, as shown diagrammatically in FIG. 13.

Controlling the temperature of the adhesive 2 deposited on the support is very important since this temperature conditions the consistency of the bead 10 and the smooth running of the process according to the invention. If one acted as simply as suggested by the diagram of FIGS. 1 and 2, one would risk having at the orifice 4 an adhesive of insufficient temperature, due in particular to the lowering of temperature in the conduit 3. A first precaution therefore consists of insulating the conduit 3, to avoid excessive temperature drops.

This, however, may prove to be insufficient and, according to the invention, a closed circuit is created in which the adhesive 2 circulates from the reservoir 1 and returning to the reservoir.

1. This circuit is thus maintained at a known and stable temperature. Then, the adhesive 2 is poured through the orifice 4 by sample in this circuit and the adhesive is heated to the immediate vicinity of orifice 4 to obtain the desired temperature with great precision (of the order of a few degrees Celsius).

For the implementation of the invention, it is advantageous to use a non-aqueous adhesive, so that it is not absorbed by the support when the latter is hydrophilic, as is the case with cardboard.

Such an adhesive is, for example a styrene isoprene-styrene without addition of solvents, having a viscosity of the order of 10,000 centipoise.

Referring now to Figures 14 and 15, there is shown a device for implementing the invention constituting a complete machine ensuring common functions (supplying panels for example) and specific functions of the invention. The ordinary functions are provided by mechanisms known to those skilled in the art and their description will be limited to understanding the invention.

The machine comprises a frame 40, guides for belts 41 constituting together a means of translation of the supports 20 relative to the machine itself. The belts

41 are in support at all the places where they undergo pressure forces (rollers 11 and 14 in particular),

The plane on which the panels are placed consists here of all of the translation belts 41. These are engaged on drive pinions 42 and on tension pinions 43.

At one end of the machine, there is a known type of mechanism, called a "feeder", 44 containing a stock of stacked supports 20 and comprising means 45 for removing these supports 20 to direct them one by one towards the belts 41 which drive them to the other end of the machine.

Above the belts 41, is the reservoir 1, the orifice 4 and an assembly 46 ensuring the supply of the protective tape 15 and the actuation of the pressure roller 11. The general operation of this device is as follows : The panels 20 are removed by the mechanism 45 and are supported by the belts 41 associated, as is known, with counter-belts together ensuring the maintenance and translation of each support 20. As soon as the downstream edge 24 of a panel 20 is plumb with the orifice 4, a detector 50 (FIG. 15) causes the flow of adhesive through said orifice 4 and this until another detector 51 (FIG. 15) perceives the arrival at its level of the upstream edge 25 of the panel 20, this detector 51 then causing the interruption of the flow of adhesive through the orifice 4.

Another detector 52 (FIG. 15) supplies the protective tape 15 as soon as the upstream edge 24 of the panel 20 approaches the plumb of the pressure roller 11. The tape 15, as explained above, adheres to the cord d adhesive 10 which has been deposited and is entrained with it under the roller 11. As soon as the upstream edge 25 of the panel 20 occurs, another detector 53 (FIG. 15) causes the cross-section of the protective tape 15 and, if necessary , stopping the mechanism (not shown) for unwinding and delivering the ribbon 15. The panel 20 is then placed on an elevator 60 which leads it, according to arrow F2, to a mechanism of known type called "stacker" 61 on which accumulate the panels 20 to a certain level and when this is reached, the entire stack is evacuated, for the storage of the panels 20, either for delivery in the state, or in view of additional operations, in particular for obtaining blanks intended to constitute containers.

A panel 20 provided with a strip of adhesive 1Q and a protective tape 15 constitutes a product according to the invention. π is a semi-finished product that can be shaped in any desired manner: printing, cutting, creasing, folding, volume setting, etc. The adhesive can be used during this shaping or later, for example for closing the finished article if it is a container (box, box, case, envelope, etc.). When the machine is served with rigid lambs, such as the panels 30 of FIGS. 3 and 4, use is made of the roller 38 which is located between the feeder 44 and the orifice 4. Thus, the softening zone is created just before that adhesive 2 flows over it, coming from orifice 4.

The pressure exerted by the roller 38 is advantageously adjustable so that the machine can be used with supports of different stiffnesses, requiring variable pressures.

This can be obtained, as is known per se, by means of a jack (not shown) whose rod acts on the axis 39.

If the supports used are not very rigid and do not require crushing, the roller 38 is neutralized.

FIG. 15 illustrates the coordination of the various specific functions of the machine with an embodiment particularly well suited to controlling the flow temperature of the adhesive.

The tank 1 is associated with a closed external circuit comprising the duct 3 and a return 70 on which there is a pump 71. The tank 1 is surrounded by an electrical heating resistor 72 protected by a heat-insulating lining 73.

A conduit 74 ends with 1 orifice 4 and is connected to the closed circuit 3 - 70 of which it constitutes a bypass which receives a solenoid valve 75 acting by all or nothing: "open" or "closed". The bypass is surrounded by a heating resistor 76 protected by a heat-insulating lining 77 as close as possible to the orifice 4.

During all the operation of the machine, the resistor 72 is supplied, and a thermostat 80 associated with a contact 81 of a relay, controls this supply to maintain the mass of adhesive 2 in pasty form at the limit of the liquid state. and at the right temperature. The pump 71 ensures the permanent circulation of adhesive to prevent a temperature gradient from being established between the upper layers and the lower layers of adhesive 2. This gives a stable temperature of the entire mass of adhesive 2, pretty much. The detector 50 is positioned so that it detects the downstream edge 24 of a panel 20 sufficiently in advance so that the substantially liquid adhesive 2 flows at the right temperature as soon as this downstream edge 24 is perpendicular to orifice 4, taking into account the following parameters:

The detector 50 actuates the solenoid valve 75, which causes the adhesive 2 to be expelled from the closed circuit and to flow through the bypass 74.

This is heated by the resistor 76 to transfer calories to the flowing adhesive 2, which is why the bypass is made of heat conducting material.

The temperature to which the branch 74 is brought and its length are established to obtain at the orifice 4 the desired temperature for the adhesive 2 to one or two degrees Celsius. The detector 51 is positioned so that it causes the solenoid valve 75 to close in time so that it no longer drips adhesive 2 beyond the downstream edge of the panels 20, taking into account the length of the bypass. 74, the contents of which continue to flow after the solenoid valve 75 has been closed. Furthermore, the double-acting cylinder 12 is supplied with pressurized fluid by two pipes (only one 82 is shown diagrammatically to simplify the drawing, this mechanism being within the reach of the skilled person) controlled by at least one solenoid valve 83. The control of this solenoid valve 83 is subjected to a feeler (not shown) either pre-adjusted or subject to parameters taking into account the thickness desired for the adhesive strip 10, the quality of the carton, the irregularities of its faces, etc.

The mechanism 46 will not be described in detail since it can be of different known types, more or less complex and comprising, consequently, more or less numerous command, guidance and control members. Its order was schematized globally, by a solenoid valve 84.

The solenoid valves 83 and 84 are slaved to the detectors 52 and 53 so that the delivery of protective tape 15 and the distance of the roller 11 from the surface of the panels 20 are constantly monitored and coordinated with the presence and absence of panels 20 on the belts 41 in the appropriate place.

The electrical circuit is connected to a current source 85 and includes a general switch 86. The heating resistor 76 is regulated by a thermostat 87 which controls a switch 88.

Naturally, in practice, this schematic circuit is more complex, in particular because it is combined with electronic circuits and components. The implementation of the invention does not require the adhesive bead to be continuous.

In FIG. 16, a continuous strip of adhesive 10 is shown schematically, but in FIGS. 17 and 18, other solutions are shown. FIG. 17 illustrates an example according to which the strip of adhesive is formed by the juxtaposition of three narrow strips 10a, 10b and 10c.

The strip is therefore discontinuous when considered in its width, but, on the other hand, each of these strips is continuous in the longitudinal direction.

FIG. 18 illustrates an example according to which the strip of adhesive is constituted by the juxtaposition of points 10d_ arranged in longitudinal and transverse lines. They could also be arranged in longitudinal lines but offset, for example in staggered rows, in the transverse direction.

The strip is therefore discontinuous both longitudinally and transversely.

If a discontinuous solution is adopted, the total quantity of adhesive must remain substantially the same as that of a continuous strip 1, in order to obtain good fixing of the support on the destination surface.

This means that a discontinuous strip like the one in FIG. 17 or in FIG. 18 has a total width greater than that of a continuous strip 10 like that shown in FIG. 16. The adhesive, set up in the factory before delivery to the customer, can be applied directly to the final product and is masked by the protective tape which can be of any color, including white, and attractive in appearance. The invention therefore applies well, not only to brown corrugated articles, but also to corrugated articles or other white material.

Referring now to Figure 19, we see that we can both use separate panels (and therefore discontinuous) and a continuous protective tape.

Schematically shown are five panels 20a_, 20b_, 2θ £, 20d and 2Cte and a continuous protective tape 15, passing, therefore, over the spaces 90, 91, 92 and 93 which separate two successive panels 20. To individualize the products consisting of a panel 20, an adhesive strip 10 and a protective tape 15, it is necessary to cut the latter. In practice, the cut is made between two panels 20, immediately after the ribbon 15 has been fixed to the second panel. The diagram in FIG. 19 therefore does not correspond to this hypothesis but it has been retained in spite of this because it simplifies the understanding of the different cutting possibilities which will now be described.

The ribbon 15 which passes over the space 90 existing between the panels θ and 20b is intact, that is to say that it is not cut.

Significantly in the middle of the space 91 which exists between the panels 20J3 and 20ç_, there is a line in phantom 94 which indicates a straight cut (transverse to the ribbon 15) which, repeated at the right of each space, leaves two tongues 15a_ and 15b_. Each finished panel 20 therefore has two tabs: the tab 15a on the side of its upstream edge 25 and the tab 15b on the side of its downstream edge 25.

The presence of these tabs may be desired to facilitate the removal of the protective tape 15 when it is necessary to use the strip of adhesive 10, leaving the user the choice of grasping which of these two tabs seems to him the most convenient.

Significantly against the downstream edge 24 of the panel 20d_, which is a limit of the space 92 which exists between the panels 2θ £ and 20d, is a line in phantom 95 which indicates a straight section (transverse to the ribbon 15) which, repeated for each space, leaves only one tab 15c_. Each finished panel 20 therefore has a single tongue 15 £ on the side of its upstream edge 25.

The presence of this tab may be desired to facilitate the removal of the protective tape 15 when the adhesive strip 10 must be used, but, here, the user no longer has the choice between two tabs. On the other hand, the tongue 15c is longer (practically double) than each of the tongues 15 and 15t ^, which can facilitate the removal of the ribbon 15. Significantly against the two downstream edges 24 and upstream 25 of the panels 20d_ and 20e, which delimit the space 93 which exists between the panels 20d_ and 20e_, there is a line in mixed lines respectively 96 and 97 which each indicate a straight section (transverse to the ribbon 15), which, repeated for each space, do not leave any tongue remaining but a fragment of ribbon 15d_ constituting a scrap to be eliminated. The finished panels 20 therefore have no tongue.

This solution may be desired when the products thus obtained are intended to be subsequently shaped mechanically, since the presence of one or two tongues may be discouraged, or even prohibited, if they risk catching in moving mechanical parts, for example. example, and then disrupt the operation of machines.

However, in all cases, it is possible to prefer the embodiment which has just been described with reference to FIG. 19 when a high machine throughput is sought.

Indeed, the installation of a segment of ribbon 15 for each panel has the consequence that one must be satisfied with a relatively slow production rate because one must allow the first millimeters of the ribbon 15 time to stick to the cord adhesive 10. By laying the tape 15 continuously, there is only one primer, at the start of production, and there is no longer any fear of the tape 15 coming off even at high speed because the strong traction which results on the tape 15 for unwinding it is balanced by a considerable resistance to detachment, because the tape extends continuously over the length of two panels 20.

This production gain can more than offset the increase in the amount of ribbon consumed.

In addition, as the tape is retained by the adhesive strip 10 of two successive panels, the intensity of the bonding can be lowered, which allows the use of inexpensive tapes 15 and which makes it possible to remove this tape 15 more easily when using the adhesive strip 10.

***

Claims

R E V E N D I C A T I O N S

1- Method for manufacturing a product consisting of a support (6-20) on which there is an adhesive (2-10) with prolonged effect and a protective tape (15) for a deferred use of said adhesive (2- 10), characterized in that a support (6-20-30) is chosen, one face (22-32) of which must receive the adhesive (2-10) has irregularities (36-37), which the the adhesive (2) is heated to a temperature at which it is pasty at the limit of the liquid state, then it is led to at least one orifice (4) opening out above a plane ( 5) on which the support (6-20-30) is placed, then causing it to flow at the same time as causing a relative movement between the support (6-20-30) and the orifice ( 4) so that the adhesive (2) is deposited on the support (6-20-30) along at least one thick bead (10), in particular continuous, so that the temperature of the adhesive (2) deposited is lowered to increase its viscosity until it is pasty to the limi te of the solid state, and that one exerts on the pasty adhesive (2-10) a pressure intended to cause the lateral spreading and the rolling of the bead (10) over its entire length, then that one optionally proceeds to at least a subsequent cutting of the product consisting of a support (6-20-30), an adhesive strip (2-10) and a protective tape (15).

2- Method according to claim 1, characterized in that the product is intended to be shaped after placement of the adhesive (2) and the protective tape (15), in order to constitute a finished article, ready for use by use of the adhesive (2) discovered by removing the protective tape (15).

3- A method according to claim 1, characterized in that the support (30) being made of a relatively rigid material, it is subjected to a pressure force located in the area where one must cause the flow of the adhesive (2), in order to obtain a softening of the support (30) which, in this zone, thus becomes more flexible than at the origin. 4- A method according to claim 3, characterized in that the pressure force concerns a strip whose width is greater than that of the adhesive (10) after spreading.

5- Method according to claim 3, characterized in that in that the pressure force is calibrated to be greater than the elastic resistance of the material forming the support (30).

6- A method according to claim 3, characterized in that the support material having an internal honeycomb structure, as is the case of corrugated cardboard whose grooves (31-34) create longitudinal cells (35), the effort pressure is calibrated to be able to break the walls (34) of the cells (35) forming spacers between two opposite faces (32 and 33) of the support (30) but insufficient to remove any elasticity perpendicular to said faces (32 and 33). 7- A method according to claim 1, characterized in that being implemented in a room at room temperature, the temperature of the adhesive (2-10) is lowered by simple absence of heating and by causing the movement relating to a speed such that the time which elapses between the deposition of the adhesive (2) and its spreading by pressure corresponds to the desired temperature reduction.

8- A method according to claim 1, characterized in that being implemented in a room at room temperature, and the relative movement having a given speed, pressure is exerted on the adhesive (2-10) at a distance of the flow orifice (4) such that the time which elapses between the deposition of the adhesive (2-10) and its spreading by pressure corresponds to the desired temperature reduction.

9- A method according to claim 1, characterized in that after deposition, the adhesive bead (10) is subjected to positive cooling means, such as a flow of cold air.

10- A method according to claim 1, characterized in that the support (6-20) is cardboard or similar material, which is placed on the adhesive bead (10) previously deposited on the support (6- 20) a ribbon (15) of thin material, impermeable to the adhesive (2-10) and weakly sensitive to the action of said adhesive (2-10) and in that in order to spread the bead of adhesive (10) on the support (6-20), pressure is exerted on the tape (15) .

11- Method according to claim 1, characterized in that the support (6) is made of cardboard or similar material wound over a great length in the form of a coil (7), that at least one bead of longitudinal adhesive is deposited ( 10) at the same time as the support (6) is unwound, a ribbon (15) made of thin material, impermeable to the adhesive (2-10) and weakly sensitive to, is placed on the cord (10) the action of said adhesive (2-10), that in order to spread the bead of adhesive (10) on the support (6), pressure is exerted on the tape (15) and that this assembly is wound up ( 6-10-15) according to a spool (13) for storage.

12- Method according to claim 1, characterized in that the support (6) is made of cardboard or similar material wound over a great length in the form of a coil (7), that at least one bead of longitudinal adhesive is deposited ( 10) at the same time as the support is unwound (6), that a ribbon of thin material (15) is impermeable to the adhesive (2-10) and slightly sensitive to the cord (10) the action of said adhesive (2-10), that in order to spread the bead of adhesive (10) on the support (6), pressure is exerted on the tape (15), which is rolled up this assembly ( 6-10-15) according to a reel (13) for storage, then before using the adhesive (2) the support (6) is cut into panels intended to constitute blanks, in particular for obtaining of containers.

13- Method according to claim 1, characterized in that the support is a panel (20) of cardboard or similar material, which is deposited at least one bead (10) on said panel (20) with a first edge ( 24) that the latter has at a second edge (25) opposite to the previous one (24), that a ribbon of thin material (15), impermeable to the adhesive (2-10) is placed on the cord (10) ) and weakly sensitive to the action of said adhesive (2-10), that in order to spread the adhesive cord (10) on the support (20), pressure is exerted on the tape (15) then, that 'possibly, imperfect margins are eliminated. 14- Method according to claim 1, characterized in that the support is a panel (20) of cardboard or similar material, which is treated several panels (20) brought one after the other leaving a space between them ( 90-93), that at least one bead (10) is deposited on each panel (20) with a first edge (24) which they present at a second edge (25) opposite the previous one (24), that 1 A ribbon of thin material (15) is impermeable to the bead (10), impermeable to the adhesive (2-10) and slightly sensitive to the action of said adhesive (2-10), a ribbon (15 which is continuous and which extends from one panel (20) to another over the space (90-93) which separates them and, that in order to spread the bead of adhesive (10) on each panel (20) , pressure is exerted on the ribbon (15) perpendicular to each panel (20), and then a ribbon (15) is cut between the panels (20). 15. A method according to claim 14 , characterized in that the cut is effe cut against the two opposite edges (24 and 25) of each panel (20).

16- Method according to claim 14, characterized in that the cutting is carried out between the two facing edges (25 and 24) of two neighboring panels (20).

17- The method of claim 14, characterized in that the cut leaves at least one segment (15 -15b-15c-15d_) of ribbon (15) beyond at least one of the edges (24 or 25) ) of each panel (20). 18- Method according to claim 1, characterized in that the support (6-20) is made of cardboard or similar material, which is placed on the bead of adhesive deposited (10) a ribbon of thin material (15), impermeable to the adhesive (2-10) and weakly sensitive to the action of said adhesive (2-10), in order to spread the bead of adhesive (10) on the support (6-20), pressure on the tape (15), the quantity of adhesive (2) deposited and the value of the pressure exerted on the tape (15) being coordinated so that after spreading the bead (10), the width that l adhesive (2-10) occupies on the support (6- 20) is at most equal to that of said tape (15). 19- A method according to claim 1, characterized in that the support (6-20) is made of cardboard or similar material, that 1 'is placed on the bead of adhesive deposited (10) a ribbon of thin material (15), impermeable to the adhesive (2-10) and weakly sensitive to the action of said adhesive (2-10) and in that the bead (10) is spread only when the temperature up to which it s '' is lowered after deposition on the support (6-20) has sufficiently increased its viscosity so that its degree of adhesion to the ribbon of thin material (15) is significantly lower than the degree of adhesion that it has with the support (6 -20).

20- A method according to claim 1, characterized in that the support (6-20) is cardboard or similar material, which causes the flow of the adhesive (2) through an orifice (4) which has a section and an ^orientation such that the adhesive bead (10) deposited by flow has a substantially circular cross section, that the ribbon is placed in thin material (15) at a distance from said orifice (4) by coordinating this distance , the temperature at which the adhesive (2) is deposited on the support (6-20) and the speed of relative movement, so that the bead of adhesive (10) sags a little laterally, which is then applied on the adhesive bead (10) a ribbon of thin material (15), impermeable to the adhesive (2-10) and slightly sensitive to the action of said adhesive (2-10) and that in order to spread the bead of adhesive (10) on the support (6-20), pressure is exerted on the tape (15). 21- Method according to claim 1, characterized in that the support (6-20) is made of cardboard or similar material, which is deposited at least one bead of adhesive (10), which is placed on it- ci u a ribbon of thin material (15), impermeable to the adhesive (2-10) and slightly sensitive to the action of said adhesive (2-10), that in order to spread the bead of adhesive (10) on the support (6-20), pressure is exerted on the strip (15), which is deposited and laminated at least u bead of adhesive (10) in sufficient quantity so that the bead (10) after its spreading, fills all said irregularities and also offers the ribbon of thin material (15) a flat and continuous surface. , 1 42

22- Method according to claim 1, characterized in that the support (6-20) is made of cardboard or similar deformable material, that the support (6-20) is flattened at least according to the area to receive said adhesive (2 ), that at least one bead of adhesive is deposited (10), that a ribbon of thin material (15) is applied thereto, impermeable to the adhesive (2-10) and slightly sensitive to the action of said adhesive (2-10) and that in order to spread the bead of adhesive (10) on the support (6-20), pressure is exerted on the tape (15).

23- A method according to claim 1, characterized in that the support (20) is made of cardboard or similar deformable material, that a regular recess (28) is produced over the entire area to receive said adhesive (2-10), that at least one bead of adhesive (10) is deposited in said hollow (28), that a ribbon of thin material (15) impermeable to the adhesive (2-) is placed on said bead 10) and weakly sensitive to the action of said adhesive (2-10), that in order to spread the bead of adhesive (10) in the hollow (28) of the support (20), pressure is exerted on the tape ( 15), the depth of said hollow (28) being substantially equal to the total thickness of the adhesive (2-10) spread and the ribbon of thin material (15). 24- The method of claim 1, characterized in that the adhesive is heated (2), that it is circulated in a conduit in a closed circuit (3-70) and in that one causes said flow by removing a fraction of adhesive (2) circulating in the closed circuit conduit (3-70). 25- A method according to claim 1, characterized in that the adhesive is heated (2), that it is circulated in a closed circuit conduit (3-70), that the adhesive is maintained ( 2) which circulates in the closed circuit conduit (3-70) substantially at the temperature which it must have for its flow and which one causes said flow by removing a fraction of adhesive (2) circulating in the conduit in closed circuit (3-70).

26- Method according to claim 1, characterized in that the adhesive is heated (2), that it is circulated in a closed circuit conduit (3-70), that one takes a fraction of adhesive (2) circulating in the closed circuit conduit (3-70), that the temperature of the adhesive fraction (2) withdrawn is increased and that said fraction is then caused to flow.

27- Device for manufacturing a product consisting of a support on which there is a long-acting adhesive and a protective tape, for a deferred use of said adhesive, characterized in that it comprises a frame (40), guides for at least one support (20) intended to receive adhesive (2), at least one reservoir (1) of adhesive (2), means for heating (72) of said adhesive (2) in the reservoir ( 1), at least one conduit (3-74) extending from the reservoir (1) to at least one orifice (4), means (75) for closing and opening the conduit (3-74 ) close to the orifice (4) as well as control means (50 to 53) of said means (75) for closing and opening, means (41) for setting relative movement of said orifice (4) and d '' at least one support (20) intended to receive adhesive (2), means (11-12) capable of exerting pressure and rolling in a direction substantially perpendicular to a plane in which must s hole ver support (20) intended to receive adhesive (2) and means (41-60-61) for evacuating supports (20) after reception of adhesive (2).

28- Device according to claim 27, characterized in c u_'il comprises means (38-39) for exerting a pressure perpendicular to the plane of a support (30) for receiving an adhesive (2-10).

29- Device according to claim 28, characterized in c that the means for exerting pressure consist of a scab (38) rotatably mounted and biased towards the plane of the support (30) selo an advantageously adjustable force. 30- Device according to claim 28, characterized in c that the roller (38) has a width greater than that which the adhesive (10) must avoi after spreading.

31- Device according to claim 28, characterized in c that the roller (38) is mol1été and positively driven in rotation. 32- Device according to claim 27, characterized in that it is located in a room at room temperature and that the means (11-12) capable of exerting pressure and rolling are remote from the orifice (4). 33- Device according to claim 27, characterized in that it comprises positive cooling means located between the orifice (4) and the means (11-12) capable of exerting pressure and rolling.

34- Device according to claim 27, characterized in that it comprises storage means (7-44) of at least one support (6- 20) of cardboard or similar material, storage means (16) of at least one strip (15) of thin material, impermeable to the adhesive (2) and weakly sensitive to the action of said adhesive (2), means (1-3-4) for depositing adhesive (2) , means for guiding said strip (15) over adhesive (2-10) deposited on the support (6-20), means (11-12) for simultaneously pressing the strip (15) on the adhesive (2-10) and adhesive (2-10) on the support (6-20) as well as means (13- 60) for evacuating for storage the support (6-20) -adhesive assembly ( 10) - tape (15). 35- Device according to claim 27, characterized in that it comprises means for supporting at least one coil (7) of support (6) made of cardboard or similar material, means (1-3-4) for depositing adhesive (2), means for unwinding the support (6) and scrolling it facing at least one orifice (4) for adhesive flow (2), storage means (16) for at least at least one strip (15) made of thin material, impermeable to the adhesive (2-10) and weakly sensitive to the action of said adhesive (2-10), means for guiding said strip above adhesive (2- 10) deposited on the support (6), means (11-12) for simultaneously pressing the tape (15) on the adhesive (2- 10) and the adhesive (2-10) on the support (6) , means for winding the support (6) -adhesive (2-10) -strip (15) assembly according to at least one coil (13) and means for supporting said coil (13). 36- Device according to claim 27, characterized in that it comprises storage means (44) of at least one stack of panels (20) made of cardboard or similar material, means (45) for collecting and distributing said panels (20) one by one, means for guiding said panels, means (41) for unitary displacement of said panels (20) in view of their running opposite at least one orifice (4) for flow of adhesive (2), means (1-3 4-50 to 53) for depositing adhesive (2-10) from a first edge (24) that each panel (20) has at a second opposite edge (25) in the first (24), means for storing at least one strip (15) of thin material, impermeable to the adhesive (2-10) and slightly sensitive to the action of said adhesive (2-10), means for guiding said strip (15) over adhesive (2-10) deposited on each panel (20), means (11-12) for simultaneously pressing the strip (15) on the adhesive (2- 10) and adhesive (2-10) on each panel (20), means for cutting said ribbon, means for evacuating (41-60) from the panel (20) -adhesive (2-10) -tape assembly (15) and means for depositing each of said assemblies (20-2-10-15) on top of each other to form at least one pile. 37- Device according to claim 27, characterized in that it comprises storage means (44) of at least one stack of panels (20) made of cardboard or similar material, means (45) for collecting and distributing said panels (20) one by one, means for guiding said panels, means (41) for unitary displacement of said panels (20) in view of their running opposite at least one orifice (4) for flow of adhesive (2), means (1-3 4-50 to 53) for depositing adhesive (2-10) from a first edge (24) that each panel (20) has at a second opposite edge (25) in the first (24), means for storing at least one strip (15) of thin material, impermeable to the adhesive (2-10) and slightly sensitive to the action of said adhesive (2-10), means for guiding said strip (15) over adhesive (2-10) deposited on each panel (20), means (11-12) for simultaneously pressing the strip (15) on the adhesive (2- 10) and adhesive (2-10) on each panel (20), means for simultaneously cutting said ribbon (15) and a small fraction of the panel near the first and second edges (24 and 25) of each panel (20), means for evacuating the cut fractions, means for evacuating (41-60) from the panel (20) -adhesive assembly (2 -10) -strip (15) and means for depositing each of said assemblies (20-2-10-15) one on the other to constitute at least one pile.

38- Device according to claim 27, characterized in that it comprises at least one orifice (4) located above a plane on which there must be a support (6-20) so that the adhesive (2 ) having to flow through said orifice (4) falls vertically on the support (6-20).

39- Device according to claim 27, characterized in that it comprises at least one orifice (4) with circular horizontal section and located above a plane on which must be a support (6- 20) so that the adhesive (2) having to flow through said orifice (4) falls vertically on the support (6-20) in a circular section

40- Device according to claim 27, characterized in that it comprises a frame (40), guides for at least one support (6-20) intended to receive adhesive (2), at least one reservoir (1 ) of adhesive (2), means of heating (72) of said adhesive (2) in the reservoir (1), at least one conduit (3-70) extending in closed circuit to and from said reservoir (1) , a branch (74) of heat conductive material, which is connected to said duct (3-70), which ends in an orifice (4) and which comprises means (75) for closing and opening organs heater (76) being placed outside said branch (74), the device further comprising means for regulating the heating means (72) of the tank (1) and heating elements (76) of the branch (74).

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