Online corrugated board laminating equipment

Abstract

An online corrugated cardboard apparatus comprises: a first corrugated group (10) adapted to form a first fluted corrugation (C1); a second set of corrugations (20) adapted to form second fluted corrugations (C2); a laminating machine (50) comprising a magazine (52) of laminates (51); and a coupling unit (60) for coupling the laminate (51), adapted to couple the laminate (51) to one or more of the fluted corrugations (C1, C2) to form a laminated corrugated cardboard. The apparatus comprises a bonding unit (30) and a double backing unit (40) arranged downstream of the two corrugation groups (10, 20) and upstream of the laminating machine (30) with respect to a movement direction (F) in a longitudinal direction (X-X) in which the fluted corrugations (C1, C2) move.

Description

Technical Field

[0001] The present invention relates to the field of equipment for producing single - wave or double - wave corrugated cardboard, and is developed specifically for on - line corrugated cardboard lamination equipment. Background Art

[0002] Known types of lamination equipment generally include a laminator that is particularly suitable for joining laminate sheets to single - wave or double - wave corrugated cardboard.

[0003] Typically, an on - line laminator (i.e., a machine that forms part of a cardboard production equipment) receives at least one continuous composite cardboard, called "canneté", which is formed by connecting a corrugated (rippled) paper web to a flat paper web (cover sheet). The laminator also includes a gluer, a trimming device, and a cutting device. The gluer applies an adhesive (usually an ethylene - type glue) to the crests to allow subsequent bonding of the canneté to the laminate sheet. Subsequently, the trimming and cutting devices trim and cut the cardboard formed by the canneté and the laminate sheet to dimensions corresponding to those of the desired laminated cardboard. For example, see document DE10331357A1.

[0004] In the case of producing laminated corrugated cardboard consisting of double - wave corrugated cardboard, the laminator receives two cannetés and includes two gluers. The first canneté reaches the first gluer, which applies an adhesive (usually an ethylene - type glue) to the crests of the first canneté to join the first canneté to the cover sheet of the second canneté by bonding. Then, the second canneté encounters the first canneté, and its bottom cover sheet comes into contact with the glue previously deposited on the crests of the first canneté, forming a double - wave canneté. Then, the two joined cannetés are fed into the second gluer, where an adhesive (usually an ethylene - type glue) is applied to the waves of the second canneté to allow subsequent bonding of the double - wave canneté to the laminate sheet.

[0005] To make the layers of the two cannetés have the same width and be aligned, there are at least two cutting and trimming units in the laminator, one for each canneté, and associated waste removal systems and at least two paper alignment systems.

[0006] One of the main problems with these types of on - line lamination equipment is the use of ethylene - type glue to connect the first canneté to the second canneté. Ethylene glue allows bonding of papers under "cold" conditions (i.e., at low temperatures, such as at room temperature), but requires a predetermined period of time for the crests of the first canneté to fully adhere to the cover sheet of the second canneté.

[0007] Due to this fact, the individual paper layers to be joined together must be kept at the same speed until the joining process is completed, because any - even minimal - difference can cause relative slippage of the individual layers, which will have a negative impact on cohesion and thus on the frontal alignment.

[0008] To achieve the same speed and prevent slippage, the industry uses various additional elements, although these elements greatly complicate the laminator and the production process, resulting in a series of "adjustments" that must often be repeated even when changing the processed product.

[0009] A second important issue lies in the fact that the individual paper layers must also be aligned transversely to ensure correct application of the laminate. Therefore, before the gluing step, the two grooved corrugations must be trimmed to the appropriate size and then kept perfectly aligned throughout the process.

[0010] Numerous experiments carried out by the applicant have shown that it is necessary to overcome these problems in order to allow simplification of existing online corrugated cardboard laminating equipment while improving the characteristics of the laminated corrugated cardboard produced by this equipment.

[0011] Another requirement identified is the need to reduce the paper passage time, simplify these operations and reduce their complexity. Summary of the Invention

[0012] These requirements are met by the features of the invention as set out in the independent claims. The dependent claims define the preferred and / or particularly advantageous features of the invention. Description of the Drawings

[0013] It should be understood that the elements and features of one embodiment can be incorporated into other embodiments without further ado.

[0014] Reference will now be made in detail to various embodiments of the invention, in particular with reference to the drawings, in which:

[0015] - Figure 1 is an overall view of an online corrugated cardboard laminating device according to the invention;

[0016] - Figure 2 is a view of the first part of the device including a corrugation group Figure 1 of the device;

[0017] - Figure 3 is a view of the second part of the device including a double backing unit and a laminator Figure 1 of the device;

[0018] - Figures 4a to 4d is a different use embodiment of the gluing unit according to the invention;

[0019] -Figure 5 is Figure 1 and 3 views of the laminator as shown in; and

[0020] - Figure 6a is a simplified view of a double-wave laminated corrugated board according to the prior art;

[0021] - Figure 6b is a simplified view of a double-wave laminated corrugated board according to the present invention;

[0022] - Figure 7 is a plan view of a longitudinal cutting unit according to the present invention; and

[0023] - Figure 8 is an overall view of another embodiment of an on-line corrugated board laminating apparatus. Detailed Description

[0024] Each example is only for illustration of the present invention and should not be construed as a limitation of the present invention. For example, since the technical features shown or described form part of one embodiment, they can be incorporated into or associated with other embodiments to produce additional embodiments. It is to be understood that the present invention will include such modifications and variations.

[0025] An on-line corrugated board production apparatus according to the present invention, generally designated by 1, includes a plurality of processing devices and / or stations and / or operating units arranged in series and aligned along a longitudinal X-X, wherein the material moves in a first moving direction F along said longitudinal X-X.

[0026] With particular reference to Figure 1 , the on-line laminating apparatus 1 includes a first corrugating group 10, including a corrugator 12, and a plurality of successive paper web material cassettes 14, 16. The first cassette 14 includes a continuous paper web roll particularly suitable for forming a corrugated web. The second cassette 16 includes a roll of continuous paper web particularly suitable for connection to the corrugated web.

[0027] The corrugator 12 includes a pair of corrugating rolls suitable for forming a corrugated web, an application station for applying an adhesive (preferably a starch-based glue) to the crests formed on the corrugated board, and a pressing element for promoting the adhesion of the flat sheet to the corrugated board.

[0028] Thus, the corrugating group 10 is intended to form a fluted corrugation C1, i.e., a composite board composed of a corrugated board connected to a corresponding flat sheet.

[0029] According to this embodiment, the corrugation set 10 is configured and / or arranged such that the fluted corrugation C1 output from the corrugator 12 has waves arranged upwardly. For example, the corrugation set 10 may include one or more deflectors, such as one or more turning rollers, for deflecting the fluted corrugation C1 in such a way that the fluted corrugation C1 is conveyed in the apparatus with the waves arranged upwardly.

[0030] The in-line laminating apparatus 1 includes a second corrugation set 20, which includes a corrugator 22 and a plurality of continuous web material cassettes 24, 26. The first cassette 24 includes a continuous web roll that is particularly suitable for forming a corrugated web. The second cassette 26 includes a continuous web roll that is particularly suitable for being joined to the corrugated web.

[0031] The corrugator 22 includes a pair of corrugating rollers suitable for forming a corrugated web, an adhesive station for applying an adhesive (preferably a starch-based glue) to the crests of the corrugations formed on the corrugated board, and a press element for facilitating the adhesion of the flat sheet to the corrugated board.

[0032] Thus, the corrugation set 20 is intended to form a second fluted corrugation C2, i.e., a composite board composed of a corrugated board joined to a corresponding flat sheet.

[0033] According to this embodiment, the corrugation set 20 is configured and / or arranged such that the fluted corrugation C2 output from the corrugator 22 has waves arranged upwardly. For example, the corrugation set 20 may include one or more deflectors, such as one or more turning rollers, for deflecting the fluted corrugation C2 in such a way that the fluted corrugation C2 is conveyed in the apparatus with the waves arranged upwardly.

[0034] The in-line laminating apparatus 1 further includes an additional continuous web material cassette 100, e.g., a continuous web roll, which is suitable for forming a cover plate C0 that is associated with a cardboard web formed by a single fluted corrugation C1, C2, or with a cardboard web formed by a pair of fluted corrugations C1, C2 joined together, which will be clearer below. In Figure 1 the illustrated embodiment, the cassette for the cover plate C0 is arranged upstream of the first corrugation set, but may also have a different arrangement along the laminating apparatus 1, e.g., in Figure 8 the illustrated embodiment, the cover plate cassette 100 is arranged at an elevated position relative to the other units of the laminating apparatus 1.

[0035] The in-line laminating apparatus 1 includes a laminator 50, which is adapted to join a laminating sheet to one or more sheets of fluted corrugation C1, C2 to form a laminated corrugated board.

[0036] The in-line laminating apparatus 1 according to the present invention further includes an adhesive unit 30 and a double-backing unit 40, both of which are arranged downstream of the two corrugation sets 10, 20 and upstream of the laminator 50 in the longitudinal direction X of the material movement in the moving direction F.

[0037] The gluing unit 30 is arranged upstream of the double backing unit 40 (e.g., near the entrance of the double backing unit 40) and has the following functions: depositing a thin and uniform adhesive layer on the crests of the fluted corrugations C1, C2 from the corrugation group to allow the first fluted corrugation C1 to be glued to the second fluted corrugation C2, or the fluted corrugations C1, C2 to be glued to a paper or cover sheet web C0. As will be shown more clearly below, the gluing unit 30 can consist of one or two levels to allow the production of single-wave or double-wave cardboard webs; each level is responsible for applying glue to the crests of the corresponding fluted corrugations C1, C2.

[0038] As described above, the configuration and / or arrangement of the corrugation groups 10, 20 are such that at least one of the fluted corrugations C1, C2 has an upwardly arranged wave at least at adjacent positions upstream of the gluing unit 30.

[0039] According to the embodiment shown in the figures, the gluing unit 30 includes a first gluing device 32 through which the first fluted corrugation C1 supplied from the first corrugation group 10 can pass inside; and a second gluing device 34 through which the second fluted corrugation C2 supplied from the second corrugation group 20 can pass inside.

[0040] The fluted corrugations C1, C2 are inserted into the gluing unit 30 in such a way that at the entrance and exit of the gluing devices 32, 34, their waves are arranged upward.

[0041] The distribution of the glue is carried out by passing the fluted corrugations C1, C2 through a gluing roller and a pressing roller. The latter applies a slight pressure to the fluted corrugations on the cover sheet side to bring the crests into contact with the gluing roller that applies a uniform dose of adhesive.

[0042] Referring to the embodiment shown in the accompanying drawings, each gluing device 32, 34 includes a reservoir for an adhesive (preferably a starch-based glue), and at least one gluing roller 31 designed to pick up the glue from the reservoir during use and distribute a glue layer on the crest portions of the respective fluted corrugations C1, C2.

[0043] Each gluing device 32, 34 includes a turning roller 33 fixed to a support arm 35. The arm 35 is movably engaged with the gluing devices 32, 34 such that the turning roller 33 can be selectively moved towards and away from the gluing cylinder 31. According to this configuration, the turning roller 33 can assume a rest position in which the turning roller 33 is arranged at a certain distance from the gluing cylinder 31, and can assume an operating position in which the turning roller 33 is arranged close to the gluing cylinder 31. In the rest position, the fluted corrugations C1, C2 passing over the turning roller 33 do not reach close to the gluing cylinder 31, and the glue layer is not dispensed on top of the crests of the respective fluted corrugations C1, C2. In the operating position, the turning roller 33 exerts a slight pressure on the fluted corrugations C1, C2 on the cover plate side so that the crests come into contact with the gluing cylinder 31 that applies a uniform dose of adhesive.

[0044] Figures 4a to 4d Some possible embodiments of the gluing device according to the present invention are shown.

[0045] In Figure 4a In the first gluing device 32, the turning roller 33 is in the operating position, and the gluing cylinder 31 applies glue to the crests of the first fluted corrugation C1. Differently, in the second gluing device 34, the turning roller 33 is in the rest position, and the gluing cylinder 31 does not apply glue to the crests of the second fluted corrugation C2. According to this embodiment, the two fluted corrugations C1, C2 are glued together, and the crests of the second fluted corrugation C2 are joined to the cover plate of the first fluted corrugation C1. Then the two fluted corrugations C1, C2 are inserted into the double backing unit 40 to complete the gluing operation, and once the laminate has been applied to the laminator 50, a double-wave laminated corrugated board is obtained.

[0046] In Figure 4b only the second fluted corrugation C2 is inserted into the gluing unit 30, and the turning rollers 33 of the two gluing devices 32, 34 are in the rest position. According to this embodiment, once the laminate has been applied to the second fluted corrugation C2 in the laminator 50, a single-wave laminated corrugated board is obtained.

[0047] In Figure 4c in the two gluing devices 32, 34, the turning rollers 33 are in the operating position, and the gluing roller 31 applies glue to the crests of the respective fluted corrugations C1, C2. According to this embodiment, the two fluted corrugations C1, C2 are glued together, the crests of the second fluted corrugation C2 are joined to the cover plate of the first fluted corrugation C1, and the cover plate C0 is glued to the first fluted corrugation C1, and the crests of the first fluted corrugation C1 are joined to the cover plate C0. Then, all the paper layers are inserted into the double backing unit 40 to complete the gluing and obtain a double-wave corrugated board web.

[0048] In Figure 4dAmong them, only the first fluted corrugation C1 is inserted into the gluing unit 30, and the turning roller 33 of the first gluing device 32 is in the operating position. Therefore, the gluing roller 31 applies glue to the peaks of the first fluted corrugation C1. According to this embodiment, the cover plate C0 is glued to the first fluted corrugation C1, where the peaks of the first fluted corrugation C1 are connected to the cover plate C0. Then, all the paper layers are inserted into the double backing unit 40 to complete the gluing and obtain a single-wave corrugated cardboard web.

[0049] Obviously, in addition to those described and shown in the above drawings, other combinations of the configurations of the gluing devices 32, 34 can be envisioned without departing from the scope of the present invention. For example, a configuration similar to Figure 4b the one shown can be provided, where only the first fluted corrugation C1 is inserted into the gluing unit 30. Also in this case, once the laminate is applied to the first fluted corrugation C1 in the laminator 50, the device can produce single-wave laminated corrugated cardboard.

[0050] The configuration and / or arrangement of the gluing unit 30 is such that at least one of the fluted corrugations C1, C2 has an upwardly arranged wave at least at adjacent positions downstream of the gluing unit 30 and upstream of the double backing unit 40.

[0051] The double backing unit 40 has the function of driving one or more webs of the fluted corrugations C1, C2 from the gluing unit 30, gradually heating them, completing the process of gluing them together, and pushing them towards the laminator 50.

[0052] The double backing unit is a machine designed to bond two or more sheets of paper material together. More specifically, the double backing unit is used to bond a cover plate to a fluted corrugation to obtain a single-wave cardboard, or to facilitate the bonding of the first fluted corrugation to the second fluted corrugation to obtain a double-wave cardboard. In other words, the double backing unit can be defined as a device capable of producing at least one double-sided laminated corrugated cardboard web by associating a corrugated cardboard web laminated on one side with a laminate.

[0053] The double backing unit 40 according to the present invention can include two main parts: a first part, called the hot part, designed to heat the parts to be bonded to facilitate their adhesion; and a second part, called the cold part, designed to move the corrugated cardboard or two fluted corrugations and keep the bonded parts in contact with each other.

[0054] The hot part is formed by a support frame and two metal plates on which the fluted corrugations slide, and the metal plates are manufactured to ensure stability, easy sliding, and uniform heat transfer over the entire contact surface, thus allowing uniform bonding. Generally, the external temperature of these plates can vary between 90° and 200°C, depending on the type of cardboard to be produced and the actions performed by the plates.

[0055] Specifically, the board can be divided into a heating subgroup and a drying subgroup. The heating subgroup is designed to heat the sheets to be bonded to improve the bonding ability of the glue used, and the drying subgroup is designed to evaporate the excess moisture to obtain the correct humidity value of the corrugated board.

[0056] The top part of the double backing unit performs the driving of one or more fluted corrugations and applies a predetermined pressure to facilitate the bonding operation. It can consist of a drive drum located at the start of the double backing unit 40 and a pad guided by a drive drum located at the end of the double backing unit 40.

[0057] To ensure sufficient pressure and thus ensure correct bonding action, the force applied to the pad can be adjusted by small pressure rollers or shoes, which are cold or partially heated and designed to press the pad itself against the fluted corrugation.

[0058] As can be clearly seen from the above, the lamination equipment according to the present invention provides various alternatives for the final product, making the equipment particularly flexible and capable of producing not only double-wave laminated corrugated board ( Figure 4a ), but also various other types of products, such as single-wave laminated corrugated board ( Figure 4b ), single-wave corrugated board ( Figure 4d ) and double-wave corrugated board ( Figure 4c ).

[0059] With particular reference to Figure 5 , the in-line corrugated board lamination equipment 1 according to the present invention further includes a laminator 50, which is arranged downstream of the double backing unit 40 with respect to the moving direction (F) of the longitudinal (X-X) moving along the fluted corrugations (C1, C2). The laminator 50 includes a magazine 52 for the laminate sheet 51, an ethylene bonding machine 56 and a coupling unit 60 for coupling the laminate sheet 51 to the corrugated board.

[0060] The in-line lamination equipment 1 further includes a longitudinal cutting unit or trimming unit 54 and a transverse cutting unit 58, which are arranged downstream of the double backing unit 40 and upstream of the coupling unit 60.

[0061] In the illustrated embodiment, the laminator 50 may further include a discard unit 53 located upstream of the trimming unit 54, which is designed to discard the cardboard considered unsuitable for lamination.

[0062] With particular reference to Figure 7, the longitudinal cutting unit 54 or the trimming unit has the following functions: trimming the fluted corrugations C1, C2 to a predetermined width in a continuous manner (in the case of manufacturing single-wave laminated corrugated board) or trimming a pair of fluted corrugations C1, C2 (in the case of manufacturing double-wave laminated corrugated board), the pair of fluted corrugations C1, C2 being connected together and pre-bonded by the bonding unit 30 and the double backing unit 40.

[0063] Its function is to allow continuous processing of the cardboard on which it operates, longitudinally cutting with respect to its advancing direction, and this cutting determines the width of the cardboard output from the laminating equipment.

[0064] The trimming unit 54 includes a beam 80 extending along a longitudinal Y-Y orthogonal to the longitudinal X-X along which the fluted corrugations C1, C2 move. The trimming unit 54 also includes at least a pair of side blades 82, 84 movably arranged along the beam 80.

[0065] According to a particularly advantageous feature, the side blades 82, 84 are configured such that the cutting can be performed from above, through the blade / pair of blades contrast action of the Teflon rods located on the beam below the sliding movement plane of the cardboard, thus ensuring suitable cutting of the corrugated board, and even more suitable cutting of double-wave cardboard, because of the rigidity provided by this type of cardboard including at least four layers of corrugated paper and smooth paper bonded together.

[0066] Each side blade 82, 84 can move along the beam 80 independently of the other blade 82, 84 in order to be able to be positioned at the optimal cutting point. The working or stationary state of each blade is automatically managed and depends on the processing program.

[0067] According to one embodiment, the trimming unit 54 includes a central blade 86.

[0068] There is a suction unit downstream of the trimming unit 54, where two nozzles connected to the suction device pick up the cardboard trimmings generated by the cutting blades of the trimming unit 54.

[0069] According to one embodiment of the present invention, the two side blades 82, 84 or additional auxiliary blades 88 can be directly connected to or arranged close to the suction nozzle 90 to pick up the trimmings.

[0070] The transverse cutting unit 58 is suitable for cutting the fluted corrugations C1, C2 (in the case of manufacturing single-wave corrugated board) or cutting a pair of fluted corrugations C1, C2 connected together and pre-bonded by the bonding machine 30 and the double backing unit 40 (in the case of manufacturing double-wave laminated corrugated board), in order to divide the continuous cardboard web into cardboard sheets of a predetermined length. The transverse cutting unit 58 is arranged downstream of the ethylene-type bonding machine 56 and upstream of the coupling group 60 for coupling the laminate 51.

[0071] After being cut to a certain size, the cardboard is conveyed by a perforated belt with a vacuum sealing system to the joining unit 60 where it is joined to the laminate 51.

[0072] Thus, the in-line laminating device according to the invention produces single-wave or double-wave continuous cardboard webs, but joins the cardboard to the laminate 51 in the form of sheets in the joining unit 60. This feature is crucial for obtaining a very precise join between the cardboard and the laminate, which is usually printed, thus ensuring the high quality of the finished product.

[0073] Therefore, the advantages obtained by the present invention are obvious. The laminator 50 includes a single trimming and cutting unit 54 instead of the two trimming and cutting units present in prior art laminators, as well as the associated systems for removing material. In addition, the laminator does not require, and thus does not include, two paper alignment systems, which are present in prior art laminators. Finally, the laminator 50 includes a single ethylene-type gluer 56, which is different from prior art laminators.

[0074] Due to the above configuration, a shorter paper path layout can be obtained and the material wasted each time the device is started up can be reduced.

[0075] Another advantage of the present invention is that the longitudinal cutting or trimming is performed on a pair of grooved corrugated sheets that have been bonded together in the upstream region of the device and are thus firmly fixed together. In this way, all possible problems encountered in known types of devices, where the grooved corrugated sheets are bonded in the laminator and must be realigned after bonding and before being joined to the laminate, can be avoided.

[0076] Furthermore, it should be noted that in addition to reducing the production difficulties present in performing the processing using prior art in-line laminators, the proposed solution can obtain a higher quality and a lower cost laminated product.

[0077] The product of a conventional in-line laminator actually consists of two cold glue paper layers and two hot glue layers, as Figure 6a shown. The product achieved using the solution according to the invention consists of one cold glue paper layer and three hot glue layers, as Figure 6b shown.

Claims

1. An online corrugated board laminating device, comprising: - a first fluting group (10) comprising a corrugating machine (12) and a plurality of magazines (14, 16) of continuous paper web material, said first fluting group being suitable for forming first fluted flutes (C1), - a second fluting group (20) comprising a corrugating machine (22) and a plurality of magazines (24, 26) of continuous paper web material, said second fluting group being suitable for forming second fluted flutes (C2), - a laminating machine (50) comprising a magazine (52) for laminating sheets (51) and a coupling unit (60) for coupling the laminating sheets (51), the laminating machine being suitable for coupling the laminating sheets (51) to one or more of the fluted flutes (C1, C2) to form a laminated corrugated board, The device further comprises a bonding unit (30) and a double backing unit (40), which are arranged downstream of the two fluting groups (10, 20) and upstream of the laminating machine (50) relative to the moving direction (F) along the longitudinal direction (XX) of the fluted fluting (C1, C2), A trimming unit (54) and a transverse cutting unit (58) are arranged downstream of the double backing unit (40) and upstream of the coupling unit (60), and are respectively configured to trim to a predetermined width and transversely cut the grooved corrugated paper (C1, C2) or a pair of grooved corrugated paper (C1, C2) coupled together in a continuous manner.

2. The device according to claim 1, characterized in that The bonding unit (30) is arranged upstream of the double backing unit (40).

3. The device according to claim 2, characterized in that The flute groups (10, 20) are configured and / or arranged so that at least one grooved flute (C1, C2) has upwardly arranged waves at least at an adjacent position upstream of the gluing unit (30).

4. The device according to claim 2, characterized in that The bonding unit (30) is configured and / or arranged so that at least one grooved flute (C1, C2) has upwardly arranged waves at least at an adjacent position downstream of the bonding unit (30) and upstream of the double backing unit (40).

5. The device according to claim 2, characterized in that The bonding unit (30) comprises a starch-based glue reservoir.

6. The device according to claim 4, characterized in that The bonding unit (30) comprises two bonding devices (32, 34), each bonding device comprising a bonding roller (31) and a deflection roller (33), the deflection roller being movably engaged with the bonding device (32, 34) so ​​that the deflection roller (33) can be selectively moved toward and away from the bonding roller (31).

7. The device according to claim 1, characterized in that The laminator (50) comprises a vinyl bonder (56) arranged upstream of a coupling unit (60) for coupling the laminated sheets (51).

8. The device according to claim 8, characterized in that The longitudinal cutting unit (54) comprises at least one pair of side blades (82, 84) movably arranged along a beam (80) extending in a longitudinal direction (YY) orthogonal to the longitudinal direction (XX) in which the fluted flutes C1, C2 move.

9. The device according to claim 1, characterized in that The device comprises a cover sheet magazine (100) which is arranged in an elevated position relative to the other units of the laminating device (1).

Images