MX2012010703A

MX2012010703A - Improved method and apparatus for forming corrugated board.

Info

Publication number: MX2012010703A
Application number: MX2012010703A
Authority: MX
Inventors: Patrick Petrus Antonius Maria Van Berlo
Original assignee: Corcel Ip Ltd
Priority date: 2010-03-31
Filing date: 2011-03-31
Publication date: 2012-11-06
Also published as: CL2013002595A1; ZA201307972B; SG10201501327YA; RU2012146351A; JP2015178279A; CN104476827A; ZA201208145B; HK1178489A1; SG10201501317WA; CN102821936B; MX348400B; WO2011122968A1; EP2552686A4; CN102821936A; SG184242A1; RU2015156631A; JP2013523492A; CN104129105A; HK1200773A1; EP2552686A1

Abstract

The present invention relates to an apparatus for, and method of, bonding a substantially planar porous sheet material to a porous corrugated sheet material in a continuous process, the apparatus comprising a linear corrugator module (300) comprising a corrugating roller (306); an endless fluted conveyor belt (301) wherein the fluted surface (302) of the conveyor belt intermeshes with the teeth on the corrugating roller; a glue applicator (308); and an endless tensioned belt assembly which holds the planar and corrugated sheets together so a bond is formed between them. The production rate (and therefore the dimensions of the corrugating roll) is governed by the formula RP=DHT/BT, where RP is the rate of production in metres/minute; DHT is the distance in metres for which the respective sheets are held together; and BT is the bond time of the adhesive in minutes.

Description

METHOD AND IMPROVED APPARATUS FOR FORMING A CORRUGATED CARDBOARD TECHNICAL FIELD The present invention relates to an improved method and apparatus for forming a corrugated board. In particular, the present invention describes a method and apparatus for manufacturing a corrugated cardboard on one side and / or, in some embodiments, corrugated cardboard on both sides.

PREVIOUS ART For ease of reference only, the present invention will be described in relation to the production of corrugated cardboard on one side although this should not be seen as a limitation and certain embodiments of the present invention can be used to produce corrugated cardboard on both sides.

As used throughout this description, the terms corrugated and fluted and grammatical variants thereof are used interchangeably and refer to a series of crests (raised portions) and alternate grooves (depressed portions).

Corrugated cardboard on one side is well known and used extensively in industry, especially in packaging where it is used as a lining and sheathing. This is also used as a basic component in the production of standard cardboard (ie corrugated cardboard on both sides) and many structural objects such as boxes, panels, pallets, etc.

Corrugated cardboard sheets on one side can be joined to form multi-layer corrugated boards of various thicknesses and hardness. One reason for the wide use of corrugated cardboard is its rigidity, hardness and relatively low weight.

Corrugated cardboard on one side is produced by bonding a sheet material of corrugated paper (usually recycled paper) to a coating sheet. The coating sheet is typically kraft paper although other materials may be used.

In a conventional machine for producing corrugated cardboard (also known as fluted) on one side, the fluted sheet is formed by passing a sheet of paper between two corrugation rolls. The two rollers are arranged so that there is a gear of the teeth in the periphery of each roller. A sheet of paper is inserted between the teeth of the rollers which forces the paper towards the grooves when the teeth of the rollers are engaged. The fluted sheet is held in contact with the teeth at the periphery of one of the corrugation rolls, typically by a vacuum formed within the corrugation roll, at least until the coating is added.

A line of adhesive is applied to the raised portions of the flutes to join the coating to the fluted paper. A sheet of paper liner is typically pressed into the raised portions by a smooth roll so that the coating is bonded to the fluted paper thereby forming a corrugated (or fluted) cardboard on one side.

A limiting factor in this process is the requirement to maintain contact between the fluted sheet and the coating for sufficient time for the adhesive to set and form a bond. This time can be several seconds or more at normal pressures and ambient temperatures. However, time has traditionally been reduced by raising the temperature during the bonding process and applying pressure to the joint between the raised portion and the liner.

High-pressure steam is commonly used to heat the cylinders on which the fluted paper and paper move 7 coating, raising the temperature of the paper. Typical operating temperatures for corrugation rolls can be approximately 150-200 ° C.

The pressure can be applied to the joint between the liner and each raised portion by a pressure roller arranged to press the liner against the raised portion covered with adhesive. Since the contact time between the pressure roller and the corrugation roller (which holds the fluted sheet) is relatively short, high pressures are generally required to materially increase the speed of the joining process.

With this type of arrangement (higher pressure heating) the bonding time can be reduced to a few thousandths of a second, allowing a high speed production of corrugated cardboard on one side. However, a problem with this arrangement is that the high pressure exerted by the pressure roller can distort the paper and leave unsightly marks on the surface of the coating paper, reducing its value.

Some machines are other devices, such as endless belts, for pressing the coating and fluted sheets together when they are moved around the corrugation roll. When the time period in which the pressure is applied is extended, lower pressures may be used so that the surface of the paperboard does not deform.

A typical arrangement of an apparatus for producing corrugated cardboard on one side as described above in a general manner is described in U.S. Patent No. 5,951,817 (Thomas).

The machinery described in U.S. Patent No. 5,951,817 has a limited contact time (and therefore a limited bonding time) between the fluted sheet and the coating - as evidenced by the combination of fluted sheet / coating that it comes in contact with only one third of the circumference of the corrugated cogwheel. Such limited contact time requires the use of a quick-drying adhesive such as a starch-based glue typically used in the industry. Unfortunately, starch based adhesives require the application of heat (in the order of 150 ° C approximately) to activate them. This leads to the disadvantages that are discussed below.

Although the use of heat can shorten the time required to form a bond between the fluted sheet and the coating, thereby facilitating high performance, this introduces a number of engineering issues that significantly increase the cost of machinery and the costs of operation for the process. The use of high pressure steam requires boilers, pipes and a casing to ensure steam containment at all times. There is a need for additional safety measures to ensure that the steam is produced and handled correctly and that the heat produced does not provide a safety risk during the operation of the machine. Typically an engineer is required in heating processes to operate the boiler and maintain the heating system, adding cost of additional expert work, as well as the potential stoppage of production if an appropriately qualified engineer is not available.

The addition of a high pressure steam system to the basic elements of the machine inevitably leads to an increase in the size of the machine and therefore the space required for the operation of the machine. The requirement of more space adds operating costs for the production of fluted cardboard on one side.

In addition, high pressure steam is very corrosive to many materials, and parts of the machine exposed to steam, for example corrugation rollers, need to be made of corrosion resistant materials. Such materials, for example 48CrMo alloyed steel hardened with standard HRC 58-62, are generally expensive and heavy. An apparatus made of such materials may require a substantial support structure to maintain the structural integrity of the machine.

A problem with both methods of applying pressure (roller and tape) is that the applied pressure can extend some of the adhesives away from the line of contact between the coating and the raised portion of the fluted sheet, thereby wetting the surrounding paper. The adhesive, which extends away from the raised portion (ie the contact line), will not dry quickly like the adhesive along the raised portion since it is not under pressure, and typically this does not form a union between two sheets of material. As a consequence the excess (extended) adhesive remains wet for a longer time which can lead to deformation problems of the cardboard when it dries at an uneven rate, and cutting or some additional process is difficult until it is completely dry. A common solution is to apply additional heating to dry the paper and the excess (extended) adhesive. However, this adds production costs and can limit the speed of the process.

The extended adhesive can also be transferred to the surface of the pressure applying device (e.g. roller or belt) requiring the surface to be cleaned continuously. In addition, part of the extended adhesive can be transferred to the outer surface of the coating, which can cause problems during storage when rolled up, since neighboring sheets can stick together leaving the product unusable. In addition, the excess of extended adhesive can mark the surface, adversely affecting the appearance and value of corrugated cardboard.

A further disadvantage with conventional machines is that typically both the feed rollers (used to feed the paper to the corrugating rollers if it is to be scored or used as a coating) and the corrugating rollers, are heated to dry the paper before add the adhesive. This is done to reduce the moisture content of the paper and to decrease the bonding time. The production of high pressure steam to heat the corrugating rollers and to preheat the paper may require a significant amount of energy. All the above factors can be added significantly to the costs of corrugated cardboard on one side made by conventional processes and machines.

The applicant has previously addressed many of these subjects in his PCT application WO2009 / 145642. However, it would be useful if a method and formula could be provided which can be used to: manipulate the configuration of the machine; I Accurately predict the manufacturing speed; when a cold process is used for the manufacture of corrugated sheet material.

In particular it would be useful if a manufacturing method could be provided which is optimized.

Previously, in WO2009 / 145642, the applicant thought that the production rate was determined by the diameter and speed of rotation of the second (larger) corrugation roller. The applicant also thought that the fact of the endless belt extended about three quarters of the second corrugating roller set the rotation speed to approximately 20 revolutions per minute. The Applicant mentions that for a second corrugation roll having a diameter of 1.6 m the production rate was about 100 m / min of corrugated cardboard on one side.

However, it was evident that the previous production rate was at best a rule of three and a more accurate production rate formula was necessary before constructing a machine to produce one-sided cardboard - to ensure that the machine meet the expected demand. The need for a more accurate rate of production formula is based particularly on the time, expenses and costs involved in the construction of a corrugation apparatus. It would be useful if a more accurate way of determining, in advance, the production rate could be provided.

At present, due to the heat used in the production of the corrugated sheet material it is not possible to attach the preprinted sheet material directly to the corrugated sheet material since the heat damages the print.

Therefore, flexographic rubber printing stereos are typically used to apply printing but since they require pressure to apply ink to the coating attached to the corrugated sheet material this damages the flutes of the corrugated sheet material. Since the grooves are slightly flattened by the rubber printing stereos by flexography this reduces the strength (ie the structural integrity) of the board. In addition, the ink rollers can only produce a low print quality on the cardboard, as can be seen in many fruit or apple boxes.

Therefore, it would be useful if a way of applying the preprinted sheet material directly to the corrugated sheet material could be provided as part of a continuous in-line process for the manufacture of single or double-sided cardboard. In particular a method which allows the pre-printed sheet to form the coating would be an advantage as this reduces the amount of material and the manufacturing steps and the time required to produce the boxes or other promotional corrugated cardboard material.

An additional problem with conventional corrugators is that: the application of heat to paper; combined with the continuous braking force applied to the paper exiting the spool maintains its straight path; All this results in the corrugated cardboard that is produced is rolled in the corners and therefore is not a completely flat sheet (as seen with the naked eye) which would be a final product with a higher value without waste.

Continuous braking is required because the paper that is already wound on the reel from the pulp and paper mill is subjected to tension forces to the left and right, which causes the paper to deviate from a straight path when it unwinds from the coil.

It is an object of the present invention to solve existing problems or at least offer the public a useful alternative.

All references, including any patents or patent applications cited in this description, are incorporated herein by reference. It has not been admitted that any reference constitutes an earlier art. The debate around the references suggests that their authors and applicants reserve the right to question the accuracy and relevance of the cited documents. It will be clearly understood that although reference is made in this document to a number of publications of the prior art, these references do not constitute an admission that any of these documents forms part of a general knowledge common in the proceeding, in New Zealand or in another country.

It should be known that the term 'comprises' can be attributed with any exclusive or inclusive meaning, depending on the jurisdiction. For the purpose of this description, and unless otherwise specified, the term 'comprises' will have an inclusive meaning - that is, it will be taken as meaning an inclusion of not only the components listed directly in the references, but also of the elements or components not specified. This logic will also be used when the term 'understood' or 'comprising' is used in relation to one or more steps in a method or process.

Additional aspects and advantages of the present invention will be apparent from the following description which is provided by way of example only DESCRIPTION OF THE INVENTION The term 'continuous process' as used herein refers to a process in which the corrugated sheet material can be attached to the flat sheet material immediately after formation of the corrugated sheet material by meshing the rolls of large and smaller corrugation imparting the flutes to a sheet material previously flattened so as to allow the production of single-sided cardboard by a single (ie uninterrupted) continuous process.

According to one aspect of the present invention there is provided a method for attaching a substantially flat sheet material to a corrugated sheet material which becomes porous using a continuous process, the method characterized by the steps of: a) applying a controlled amount of adhesive to the vertex contact portion of the corrugated sheet material; b) holding the respective corrugated and flat sheets together at a specific pressure and during a specific pressure application period so that a joint is formed between them.

Preferably, steps a) and b) are carried out at room temperature.

In some preferred embodiments the adhesive is applied and placed at room temperature. In other embodiments the adhesive can be heated before application (depending on the nature of the adhesive used) but in all these embodiments the selected adhesive must be one that will be placed at room temperature.

The term 'vertex contact portion' as used herein refers to the upper portion of the raised portion of a groove in a corrugated sheet material which is pressed until it meets the flat sheet in step b) of the process. The contact portion of the vertex includes the vertex of the raised portions and the region on each side of it that will be pressed in direct contact with, and then it is joined, by the extension of the adhesive, to the flat sheet (coating). The inventor has found that significant problems occur if the adhesive extends beyond the vertex contact portion on the sides of the corrugations. Such problems include: - increased bonding time since the porosity of the coating can not absorb moisture in the outer adhesive of the apex contact portion; - waste of adhesive; - dimples in the grooves; Rolled cardboard if the single-sided cardboard is used to produce double-sided cardboard.

Preferably, the specific pressure is as high as possible without compromising the integrity of the paper. In preferred embodiments, the specific pressure is less than the breaking strength of the selected porous sheet materials. The inventor has found that the higher the specific pressure the shorter the binding time.

The porous sheet material may generally be paper but may include other sheet materials with similar characteristics that make them suitable for forming a corrugated board. A key feature of the sheet material is that the porosity is sufficient to absorb substantially the majority of the moisture in the adhesive at the specific pressure.

According to another aspect of the present invention there is provided a method for joining a substantially flat porous sheet material to a corrugated porous sheet material using a substantially continuous process as described above wherein the production rate has been calculated by the formula : RP = DHT / BT where RP is the production rate in meters / minute; DHT is the distance in meters at which the two respective sheets are held together; and BT is the bonding time of the adhesive in minutes.

According to another aspect of the present invention there is provided a method for manufacturing an apparatus having large and small corrugating rollers that mesh to continuously produce a porous sheet material on one side comprising the step of using the formula: RP = DHT / BT to determine the diameter of the large corrugating roller and the percentage of the circumference of the large corrugating roller around which an endless belt assembly is needed to apply pressure so as to achieve the desired production rate; where RP is the production rate in meters / minute; DHT is the distance in meters for which the two respective blades are held together; and BT is the bonding time of the adhesive in minutes.

According to another aspect of the present invention there is provided an apparatus which joins the substantially flat porous sheet material to the corrugated porous sheet material, to produce a corrugated porous sheet material on one side as part of a continuous process which uses a large corrugating roller and a smaller glue applicator and corrugator roller assembly together with a tensioned endless belt, where the production rate of the apparatus has been determined by the formula: RP = DHT / BT where RP is the production rate in meters / minute; DHT is the distance in meters to which the two respective sheets are held together; and BT is the bonding time of the adhesive in minutes.

The term 'specific pressure application period' as used herein refers to the binding time (BT) calculated by the formula: BT = DHT / RP where RP is the production rate in meters / minute and DHT is the distance in meters at which the two respective sheets are held together.

If the apparatus of the present invention includes a larger diameter corrugation roll that meshes with a smaller diameter corrugation roll then the value of the DHT is defined as DHT = X. (n2r) where r is the radius of the largest corrugation roll, and where X is the percentage of the circumference C of the large corrugation roll around which the belt of the tensioned endless belt assembly can apply pressure while leaving enough space for the glue applicator assembly and the smallest corrugation roller. The maximum values of X increase with the increase in diameter of the largest corrugating roller as discussed below.

The terms' large roller ', large diameter corrugation roller' or 'large diameter corrugation roller which engages' or the like as used herein are interchangeable and refer to a corrugation roller having a diameter which it is at least twice the diameter of the 'smallest diameter roll', 'smallest diameter corrugation roll' or 'smaller diameter roll corrugation roll'.

According to another aspect of the present invention there is provided an apparatus which attaches a substantially flat porous sheet material to a corrugated porous sheet material, to produce a porous sheet material corrugated on one side by a continuous process, wherein the apparatus includes a large diameter corrugation roll that meshes with a smaller diameter corrugation roll, and a tensioned endless tape assembly is arranged to apply pressure on the circumferential surface of the large corrugation roll to facilitate rolling of the rolls. corrugated and flat sheets where the circumference of the large diameter corrugation roll around which the endless belt can apply tension is determined by the formula: C = (RP.BT) / X where C is the circumference of the roller (ie n 2r); RP is the production rate in meters / minute and BT is the union time in minutes; and X is the maximum percentage of the circumference around which pressure can be applied by the endless belt tensioned.

According to another aspect of the present invention there is provided an apparatus which attaches a substantially flat porous sheet material to a corrugated porous sheet material to form the corrugated porous sheet material on one side by a continuous process wherein the apparatus includes a large diameter corrugation roll that meshes with a smaller diameter corrugation roll, and a tensioned endless belt assembly which includes a tensioned tape arranged to apply pressure on the circumference of the large corrugation roll to facilitate rolling of the corrugated and flat sheets wherein the percentage of the circumference of the large corrugating roll which does not have the tape tensioned by applying pressure thereto is limited only by the relative minimum space required for the smaller corrugation roll and for the applicator assembly glue.

The inventor has discovered that instead of the rpm of the corrugation roll, the limiting factor of the rate is actually defined by the formula: RP = DHT / BT where RP is the production rate in meters / minute; DHT is the distance in meters to which the two respective sheets are held together; and BT is the union time in minutes.

Preferably, the belt assembly is configured so that the belt can apply pressure on 70% -93% of the circumference of the large corrugating roller.

In preferred embodiments, the inventor has found that the diameter of the large corrugation roll, which can vary substantially between 0.4 m - 2.0 m, determines the maximum percentage that the endless belt is capable of extending around the circumference of the corrugation roll plus large, while leaving room for: - the glue application equipment which includes a glue roller; Y - the smallest corrugation roller.

For example, for a large roll of 0.4 m in diameter, the maximum percentage at which the endless belt can extend around the periphery of the large roll is substantially 70%, and for a large roll of 2 m in diameter the percentage The maximum at which the endless belt can extend around the large roller is substantially 93%.

The inventor has found that the average circumferential distance of the large roll required to provide space for the incorporation of the glue roll and the smaller corrugation roll mentioned above may be substantially in the order of 0.45 m - 0.5 m.

In a preferred embodiment the large corrugating roller can have a diameter of substantially 0.62 m and the endless belt applies a pressure at approximately 76% of the circumference of the large roller.

In another embodiment the large corrugating roller can have a diameter of 2 m and the endless belt applies a pressure of approximately 93% around the circumference thereof.

According to a further aspect of the present invention there is a method for operating a large diameter corrugation roll that meshes with a smaller diameter corrugation roll and a tensioned endless belt comprising a pressure stage in which the Tensed tape is arranged to apply pressure on a portion of the circumferential surface of the large corrugating roll to form an adhesive bond between a substantially flat porous sheet material and a corrugated porous sheet material comprising the additional step of using the percentage of the stretch of tape around the circumference of a larger corrugation roll to determine the production rate.

According to still a further aspect of the present invention, there is provided a method for using a tensioned tape and a large diameter corrugation roll which meshes with a smaller diameter corrugation roll and glue applicator assembly to produce corrugated cardboard on one side from a flat porous sheet material and a corrugated flat sheet material, the method comprising the steps of applying an adhesive to the corrugated sheet material, at an ambient temperature, and then holding the respective corrugated and flat sheets together using the tensioned tape, during a specific period of time.

The inventor has discovered that the maximum production rate of an apparatus which includes large diameter and smaller diameter corrugating rollers that are engaged is determined by the formula: RP = X (n2 r) .BT where RP is the production rate in meters / minute and BT is the bonding time in minutes and X is the percentage of the circumference of the large corrugation roll around which pressure is applied by the tensioned endless belt.

An apparatus for manufacturing corrugated cardboard on one side from a porous sheet material where the apparatus operates at a maximum production rate determined by the formula: RP = X (n2 r) .BT where RP is the production rate in meters / minute, BT is the union time in minutes, and X is the percentage of the circumference of the large corrugation roll around which pressure can be applied by the endless belt tensioned.

A method which uses a large corrugating roller and an endless belt tensioned where the maximum production rate is determined by the formula: RP = X (n2 r) .BT where RP is the production rate in meters / minute, BT is the union time in minutes, and X is the percentage of the circumference of the large corrugation roll around which pressure is applied by the endless belt tensioned.

By way of explanation only, the above formula for the maximum production rate for the larger and smaller diameter corrugating rollers that are engaged is calculated by the roller circumference (ie n2 r) multiplied by X which is the percentage of the circumference around which the endless belt tensioned is capable of applying tension; which is multiplied by BT.

In a preferred embodiment RP is substantially in the range of at least 25 m / min - 200 m / min.

In a preferred embodiment the sheet material is kraft paper.

Kraft paper is commonly used in the formation of corrugated cardboard on one side. However, as mentioned above, other porous sheet materials can be used with the present invention and therefore the reference throughout this description to the sheet material which is kraft paper should not be a limitation.

The flat sheet material known as a coating can also be made of kraft paper.

With reference to the term "substantially flat" it should be understood that it refers to a sheet or band having a substantially flat surface, which remains as a single plane (at least when viewed with the naked eye).

In contrast, the term "corrugated" should be understood to refer to a sheet or web in which the surface is configured in a series of raised portions and alternating depressed portions (i.e., corrugations).

Corrugations in a corrugated sheet used to form a corrugated cardboard on one side are commonly referred to as strias. Striae are typically formed by passing a sheet of kraft paper through a pair of corrugating rollers positioned relative to one another so that the teeth of the corrugating rollers mesh-on either side of the kraft paper. The shape of the resulting groove depends on the shape and size of the teeth of the corrugation rollers. For example, (without limitation) a flute may be triangular, sinusoidal, trapezoidal, serrated, rhombic, square, or any other form of undulating repetition. Similarly, the size of the stria is determined by the size of the teeth and may vary depending on the final application of the corrugated cardboard on one side.

In a preferred embodiment the corrugated sheet material has flutes with a substantially triangular sectional profile.

An advantage of having grooves of substantially triangular sectional profile is that this profile is relatively simple to form using teeth conventionally formed in the corrugation rolls.

In addition, triangular grooves may have an added strength compared to some other shapes, in particular to compression along the length of a groove.

The adhesive used to bond a coating to the apex contact portions of a fluted sheet, where the coating and fluted sheet are formed from kraft paper, is typically a water based glue.

The adhesive may also be a non-water based glue which is provided as a liquid during application to the apex contact portion and can be absorbed by the porous sheet material according to the present invention.

The term "controlled amount of adhesive" refers to a measure of adhesive which is applied to the contact portion of the apex so that it does not extend beyond the vertex contact portion before or during the joining step b) . A "controlled amount of adhesive" may therefore include a band of glue, glue coating, or glue drops, which is (are) placed along, or in, the contact portion. of the apex of each elevated portion of a fluted sheet.

The controlled amounts of adhesive may vary in shape depending on the mode of application.

In some embodiments, the different quantities may be in the form of a fine line, spots, a network of interconnected fine lines, interrupted lines or dashes.

The key to achieving a bond between the respective sheets is that the adhesive first moistens and penetrates the corrugated sheet and then moistens and penetrates the second sheet (coating).

Having a controlled amount, less adhesive is applied to the fluted sheet than in the case of conventional methods. In addition, a controlled amount also ensures that the adhesive does not extend beyond the apex contact portion and especially during step b). Therefore a controlled amount allows some extensions of the adhesive to occur in dry areas of the respective sheets once the pressure has been applied to the coating and to the fluted sheet.

In a preferred embodiment the adhesive is applied through the vertex contact portion in separate drops in a manner substantially as described in the applicant's prior application, PCT WO 2009/145642, where the drops are applied to the raised portion.

It is to imagine that the drops will be small and round portions, or in the form of pear of adhesive that adheres to a surface, but this should not be seen as a limitation.

The preferred size of the drop may depend on a number of factors, including the nature of the fluted paper and the coating and the type of adhesive used. However, in all cases the size of the drop must be small enough so that the drop substantially retains its shape and does not collapse under its own weight. This is important since the relatively high volume in the surface area (as compared to a band or line of adhesive) reduces the moisture evaporation rate of the drop, thus extending the time available for the drop of adhesive to wet and penetrate the raised portion of the fluted paper and the coating before the adhesive dries.

A preferred size of the drop is in the order of 0.5 mm3. The preferred space between the drops is calculated by deining the desired thickness of the adhesive when the droplets are spread out and placed apart, so that when the spread drops reach the thickness they meet with each other.

In another preferred embodiment the adhesive is applied to the apex contact portion in the form of a continuous thin strip (i.e., a line of adhesive).

The Applicant has found that the present method can be used to produce corrugated cardboard on one side without the application of heat to effect a bond between the corrugated sheet maal and the coating sheet maal.

As used herein the "room temperature" refers to the temperature of the room / building in which the apparatus can operate and carry out the method of the present invention. In general, the ambient temperature is a temperature substantially between 5 ° C-60 ° C. More preferably an ambient temperature may be a temperature of substantially between 10 ° C-25 ° C.

It should be appreciated that the selection of the adhesive of the present invention is important. As noted in the prior art, starch-based adhesives require an activation temperature in the order of 150 ° C. Therefore, such an adhesive is not desirable for use with the present invention unless it is activated prior to application (e.g. by heating in a storage tub). Suitable adhesives that can be quickly placed at room temperature, and that have the required bond strength, are discussed lain this description.

It is a significant advantage of the present invention that corrugated cardboard can be produced without the application of heat to the porous maals that are bonded. As discussed further in the description, this eliminates the need for expensive machinery and significantly reduces the energy requirements. It should be noted that it is recognized that the application of a controlled amount of adhesive to the vertex contact portion of the porous corrugated sheet at a sufficient pressure allows the significant advantage to be achieved through shorbonding time at ambient temperatures.

In the second step of the method according to the present invention the coating is pressed against the fluted sheet at a specific pressure for a specific time so that a bond can be formed. These can be achieved by a variety of means.

In a preferred embodiment the flat sheet (liner) is pressed against the corrugated sheet (fluted) by an endless belt assembly tensioned It is well known in the art to exert pressure on a coating to press it against a fluted sheet by the use of a tensioned endless belt, and the requirements for this do not need to be discussed in great detail.

The 'specific pressure' as used herein refers to the pressure applied by the tape to the large surface of the corrugating roller which is set to be at, or to be just below, the maximum pressure that can be applied. apply without deforming the paper (coating and fluted paper). Excessive pressure can lead to wrinkling and / or tearing of the paper. The maximum pressure will vary depending on the maal used for the coating and fluted paper.

In a preferred embodiment the sheet materials are held together for a period of not less than two seconds.

The Applicant has found that when an endless belt (tensioned to hold the coating firmly against the raised portions without damaging the coating) is used, in combination with a suitable commercially available adhesive, the coating and fluted sheet need to be pressed together for a period of time. period (time of application of pressure) greater than two seconds at room temperature to ensure that the coating and fluted cardboard form a good bond.

Typically, if the pressure application time is less than about two seconds, or if the pressure between the sheets is too small, a corrugated cardboard on one side will not be formed completely or adequately. In such cases, the tension in the corrugated sheet is sufficient to break the joint, resulting in the coating coming out of the ribbed sheet.

For practical purposes at room temperature, waiting times between two seconds and four seconds are desirable, with a pressure application time of about three seconds preferred. Pressure application times greater than four seconds can be used, but are not preferred since such times can significantly reduce the rate of corrugated cardboard production on one side unless the size of the corrugation roll is increased.

However, the inventor discovered a formula that determines the specific processing time that allows a person skilled in the art to manipulate the configuration of the apparatus to achieve faster production rates within the confines of the physical properties of the paper and the adhesive that is being applied. uses.

A pressure application time of approximately two or three seconds is significantly less than that achieved by some prior art machines which use a combination of high temperature and high pressure. However, an advantage of the present invention is that it can produce quantities of corrugated cardboard on one side at an acceptable rate at room temperature. This provides the advantage of a process and apparatus which can produce corrugated cardboard on one side at a reduced cost and in a safe and environmentally friendly way.

The inventor considers that the combination of: use a controlled amount of adhesive; Apply the adhesive to the vertex contact of the corrugated sheet; hold the flat and corrugated sheets together a specific pressure application time to form a joint; Y use an adhesive that can be placed at room temperature; It allows the commercial manufacture of corrugated cardboard on one side by means of a cold process.

In a preferred embodiment the adhesive is a water-based adhesive suitable for bonding porous materials such as paper. In preferred embodiments the adhesive may be a vinyl acetate copolymer containing dispersion.

A vinyl acetate copolymer containing water-based dispersion adhesive may be preferred since, in normal use, it is a non-hazardous substance, and therefore can be used safely if normal ventilation is provided.

The vinyl acetate copolymer dispersions can be placed relatively quickly at room temperature and do not require a high activation temperature - other than starch based adhesives. These have a low viscosity, good adhesion and a long opening time. A relatively low viscosity is required to allow the adhesive to flow easily, (eg, when transferred from an applicator to the ribbed sheet) while good adhesion provides the ability to easily adhere to a surface.

The opening time is a measure of the time, under normal temperature and pressure, that the adhesive may be on an exposed surface before it loses its ability to wet the opposite surface and penetrate the fibers of the opposite surface. This wetting and penetration is required to form an effective bond between the fluted paper and the coating. An adhesive having a relatively long opening time is preferred since the adhesive can evaporate into the atmosphere sometime before application to the stretch marks.

Preferably the adhesive is Adhesin Z9129W, a vinyl acetate copolymer supplied by Henkel New Zealand Limited. The Applicant has found that Adhesin Z9129 has the required viscosity, and long opening time required for use with the present invention. For example, Adhesin ™ Z9129W has a viscosity in the range 2100-2200 m.Pa.S and an opening time of between 0.5 to 1 minute. However, it is to be imagined that other adhesives having similar properties can also be used.

The application of an adhesive (such as Adhesin (Z9129W) in the form of drops to the raised portion of a fluted sheet, and applying pressure to a coating against the raised portion for about 3 seconds to form a bond between the fluted sheet and the coating, provides a number of the significant advantages over the prior art.In particular, the method can be used to produce corrugated board on one side at room temperature.As a result there is no need to heat the corrugating rollers or to dry the corrugated cardboard on one side, which can be translated into a significant reduction in the use of energy and, therefore, in the reduction of the production costs of cardboard.

In some preferred embodiments, a glue applicator for applying a controlled amount of adhesive includes a roll wherein the outer surface of the roll has a contoured surface.

Another adhesive found to be suitable is Adhesin ™ Z9040 which takes about 2 seconds to form a bond between the ribbed sheet and the coating.

The contoured surface may be in a number of ways and in one embodiment may be an irregular or dimpled surface. In some embodiments the contoured surface may be in the form of a U-shaped groove. The roller in some other embodiments may be similar to an anilox roll.

Preferably, however, the contoured surface is in the form of thin corrugations reminiscent of a square wave.

In a preferred embodiment the contoured surface may be a corrugated surface. It should be understood that a corrugated surface refers to a surface formed with a series of raised portions and sunken portions.

In a preferred embodiment the raised portions (and the depressed portions) are substantially parallel and extend around the circumference of the roller.

In a preferred embodiment the raised portions form a spiral.

In other embodiments, the raised portions may form concentric circles.

Preferably the raised portions and the recessed portions can be formed by cutting (or shaping) a 'V' or a square-shaped groove in the surface of the glue roll. The current shape of the grooves is not critical, but a V-shaped groove is preferred since it is relatively easy to cut into a smooth cylindrical surface.

During use, the adhesive can be supplied to the glue roll by a smooth surface pick roller.

Alternatively, atomizing nozzles can be used or an air knife passing through a cuvette.

In an embodiment having a pickup roller, the pickup roller is preferably mounted adjacent to an adhesive bath so that the outer surface is coated with adhesive when the pickup roller rotates.

The glue roll is mounted with respect to the pick-up roller so that the raised portions of the glue roll make firm contact with the surface of the pick-up roller. In this way the adhesive is transferred from the surface of the pick-up roller to the grooves in the surface of the glue roll, with little or no adhesive applied to the raised portions of the applicator roll.

The space between the pickup roller and the glue roller determines the amount of glue that is applied.

Preferably the assembly of the glue roller is also such that the raised portions of the applicator roller make firm contact with the raised portions of the fluted sheet on the corrugating roller. With this arrangement, when the glue roller rotates, it picks up the adhesive in the grooves in its surface when it comes in contact with the pick-up roller, and then deposits the adhesive as droplets on the raised portions of the grooved sheet.

The amount of adhesive for each drop can be determined by the size (width and depth) of each slot, while the separation of the drops can be determined by separating the adjacent slots.

It should be appreciated that the grooves should be shallow enough to prevent too much glue from depositing on the corrugated sheet material. In other words, the grooves must be sized so that the glue is deposited only in the contact portion of the apex. In a preferred embodiment, the depth of the grooves is 0.5 mm and the width of the grooves is in the order of 1 mm.

In a preferred embodiment, the raised portion may take the form of an edge.

Preferably, the V-shaped grooves in the roller are arranged so that each groove abuts the adjacent grooves to form an edge such that a section through a series of grooves forms a continuous zigzag pattern. This arrangement can provide the minimum separation between the adjacent drops (for a given width of each slot).

In some other embodiments the raised portions may have a flat section, in which case the separation of the drops may be correspondingly greater.

The glue roll is mounted in a rotary manner so that the outer surface (raised portions) of the applicator is pressed against the raised portions of the fluted paper held in the second corrugating roller.

According to another aspect of the present invention there is provided a method for joining a substantially flat sheet material to a corrugated sheet material which becomes porous using a continuous process, the method characterized by the steps of: a) applying adhesive to the corrugated sheet material with a glue application roll (GA) which has left and right side grooves on the circumference of the roll GA which engage with the teeth in the corrugation roll where said grooves in the GA roll hold an established amount of glue in them b) holding the respective corrugated and flat sheets together at a specific pressure and for a specific time so that a joint is formed between them.

The dimensions of the grooves in the GA roller allow a line of adhesive is held in them; the teeth (or a portion thereof) on the corrugation roll and the vertex contact portion of the corrugated sheet are received therein; So that a line of adhesive can be applied to the vertex contact portion of the corrugated sheet.

According to another aspect of the present invention there is provided an apparatus for making corrugated cardboard on one side by joining a corrugated sheet material having one or more raised portions on a substantially flat sheet, which become porous, the apparatus including an applicator configured to apply adhesive to each raised portion of the corrugated sheet material, and a pressure mechanism to press the flat sheet against the elevated portion of the corrugated material characterized because the applicator is configured to apply a controlled amount of adhesive to the vertex contact portions in each raised portion of the corrugated sheet material and wherein the pressure mechanism is configured to press the sheet material against the corrugated sheet material a specific pressure for a specific time so that a union is formed between them.

Accordingly, an apparatus for making corrugated cardboard on one side according to the present invention has many features in common with some prior art machines. In particular, a fluted sheet is formed by passing a sheet material between the intermeshed teeth of the first and second corrugating rollers. The fluted sheet is held against the second corrugation roll, which has a larger diameter than the first corrugation roll, by a vacuum created inside the second corrugation roll.

When the second corrugating roller rotates, the fluted paper passes through an applicator where the adhesive is applied to the vertex contact portion of the fluted sheet. In a preferred embodiment the applicator includes a roller having a corrugated surface substantially as described above.

The corrugated surface of the glue roll and the grooved surface of the GA roll (as described above) are respectively configured to apply drops or a line of adhesive through a vertex contacting portion in a raised portion of a fluted sheet. This is contrary to conventional machines in which the applicator typically has a knurled surface so as to extend a relatively wide band or line of adhesive through the raised portion of the slot. Conventional machines therefore tend to apply more adhesive than required and the adhesive is therefore not contained within the apex contact region.

In a preferred embodiment the pressure mechanism is a tensioned endless belt assembly.

An endless belt can be configured to move around a plurality of rollers, the rollers being arranged so that the belt is held in contact with the coating when the coating and fluted sheet move around the periphery of the second roller. corrugation.

This arrangement can be achieved by placing two separate end guide rollers around the periphery of the second corrugating roller, the separation defining the distance at which the tape comes into contact with the coating. The two end guides can be mounted so as to provide pressure (via the tape) on the coating when it initially comes into contact with the fluted sheet, and again just before the fluted sheet of one face is removed from the second roll. corrugation.

The tape can be tensioned by adjusting one or more of the remaining rollers so that the tape applies pressure to the coating to press it against the fluted sheet.

Since heating is not required, a standard rubber tape can be used, instead of the more expensive materials used with heating rollers. The use of a standard rubber tape can result in less damage to the coating surface, and therefore in a superior product.

In other embodiments, the endless belt can be made of plastics or synthetic material.

An advantage of the present method, when applied at room temperature, is that the endless belt can be formed using heat-sensitive materials such as plastics, synthetics and some rubbers that would not be suitable in conventional heating processes.

In a preferred embodiment the endless belt is configured to press the sheet materials together for at least 2 seconds.

In a preferred embodiment the endless belt is configured to press the sheet materials together for a time between about 2 seconds and about 4 seconds as mentioned above.

In other words, the present invention allows the efficient production of corrugated cardboard on one side without additional requirement that heat be applied to the process.

This feature is achieved by the combination of applying a controlled amount of adhesive to the vertex contacting portion followed by pressing the coating against the fluted sheet at a specific pressure for a specific pressure application time until a bond is formed.

According to a further aspect there is provided an apparatus which attaches a substantially flat porous sheet material to a corrugated sheet material by a continuous process wherein the apparatus includes a large corrugation roll which engages with a further corrugation roll. small in which the diameter of the smallest roll is at least of a diameter substantially between 0.16 m-0.2 m and the large corrugating roll has a diameter of at least substantially between 0.4 m- 2.0 m.

The ability to form corrugated cardboard on one side at ambient temperatures provides one or more of the following advantages over the prior art.

Savings in energy costs and a lower carbon footprint than conventional methods through the elimination of the need to heat corrugation rolls and dry paper. This eliminates the requirement of high pressure steam which consumes a lot of energy.

. Savings in the cost of machinery. Since no heating is required, there is significant savings since no boilers, pipes and containments are required for high pressure steam. In addition, since the machine is operated at ambient temperatures, it can be constructed of simpler and less expensive materials, such as (without limitation) ceramics, plastics or wood. Since such materials are generally easier to form and lighter than the materials (usually hardened steel) used in conventional steam-powered machines, the machine can be cheaper to make and can be supported by lighter structures, saving again in material costs.

• Savings in space. The removal of the apparatus associated with heating can result in an appliance that requires less space than machines with conventional heating.

• Improved security. Since the machine operates at room temperature, the hazards associated with the production and use of high pressure steam do not occur for long.

• Savings in operating costs. In addition to the reduction in the use of energy, the present method can result in significantly less consumption of adhesive.

Importantly, an apparatus according to the present invention can be of a size and cost which makes it suitable for on-site corrugated cardboard production on one side. Machines with conventional heating are typically large, consume high energy and are expensive to build and operate. As a consequence, such machines are commonly operated in centralized locations, transporting corrugated cardboard on one side, or products made thereof, to consumers.

The size of the machine according to the present invention is scalable, mainly because a heating apparatus is not required. Therefore, an apparatus according to the present invention can be of a suitable size for its installation and operation at the consumer's site, for example to make packaging on the site. This can provide savings to the consumer, since the supply would be controlled by the consumer, and there would be no transport and handling costs from outside the production site.

In accordance with another aspect of the present invention, the use of the principle is provided: RP = DHT / BT in the construction of single-sided cardboard manufacturing facilities; where RP is the production rate in meters / minute; DHT is the distance in meters at which the two respective sheets are held together; and BT is the bonding time of the adhesive in minutes.

According to a further aspect of the present invention there is provided a use of a water-based adhesive in the production of single-sided cardboard.

According to still a further aspect of the present invention there is provided the use of an adhesive which may be a vinyl acetate copolymer containing dispersion.

According to yet another aspect of the present invention there is provided an apparatus for manufacturing a corrugated sheet material from a porous flat sheet material by an automated process wherein the apparatus includes: a corrugation roller; a knurled endless conveyor belt assembly having a surface of the knurled conveyor belt that includes a plurality of adjacent flutes wherein the flutes are configured to correspond with the teeth in the corrugating roller.

According to a further aspect of the present invention there is provided an apparatus for manufacturing a corrugated sheet of a face of porous material by an automated process wherein the apparatus includes: a corrugation roller; a knurled endless conveyor belt assembly having a surface of the knurled conveyor belt including a plurality of adjacent flutes where the flutes are configured to correspond with the teeth in the corrugating roller; a pressure mechanism configured to hold freshly corrugated sheet material to the surface of the knurled conveyor belt while applying an adhesive by means of a glue applicator; a tensioned endless belt assembly which holds the flat sheet material and the corrugated sheet material together so that a joint is formed between them.

It should be appreciated by one skilled in the art, that in addition to the replacement of a knurled endless belt assembly, instead of the large corrugating roller, the majority, but all the features and aspects described above in relation to the present invention they can also be applied to this conveyor without endless linear slat. With the exception, of course, of the peculiar aspects of the large corrugation roller. For example, the rate of production, specific pressure application time, adhesives, suitable porous sheet materials, all apply to the linear assembly.

The surface of the knurled conveyor belt can be in a variety of different forms without departing from the scope of the present invention.

In a preferred embodiment the surface of the knurled conveyor belt can be formed of a plurality of rotatably joined webs of rigid material which has a ribbed (corrugated) edge or surface.

In some preferred embodiments the band may be in the form of a ribbon.

In some preferred embodiments the band may be in the form of a bar which has a rectangular cross section.

The rods or slats may each have connecting portions at opposite ends thereof (with respect to the intended direction of movement along the conveyor belt) to allow a rotary union to the adjacent bands to form a surface of the belt. endless conveyor fluted.

In another preferred embodiment the surface of the fluted conveyor belt can be in the form of an endless belt. In some such embodiments, the tape may include a flexible base layer and a ribbed rigid outer layer, wherein the outer layer is configured to move around rolls forming part of the conveyor belt assembly.

The surface of the fluted belt can be made from a variety of different materials without departing from the scope of the present invention.

In a preferred embodiment the bars / slats are made of steel.

In other modalities the bars / slats can be made of plastics, wood, or composite materials.

In another preferred embodiment the bars / strips can be made from Perspex.

The teeth in the corrugator and the flutes in the endless conveyor belt can have a number of different profiles without departing from the scope of the present invention, provided the shape of the flutes which are capable of engaging with the teeth in a roller corrugation. For example the teeth on the roller can have any one of the shape profiles: A, B, C, D, E, F or G.

In a preferred embodiment the teeth / grooves can be formed by V-shaped grooves.

In some preferred embodiments the surface of the endless conveyor belt may include a number of openings that pass from the upper surface to the lower surface and are positioned substantially along the length of the surface of the endless conveyor belt. The purpose of the openings is to allow applications in which a vacuum supports the corrugated sheet material against the grooves of the surface of the endless conveyor belt.

In a preferred embodiment the openings may be in the form of slots which form a stepped pattern along the length of the surface of the endless conveyor belt.

The pressure mechanism can be in a variety of form without departing from the scope of the present invention.

In embodiments where the slats do not include the openings as mentioned above the pressure mechanism may be in the form of two or more elongated fingers which pass through radial grooves in the corrugation roll and in the glue roll. Alternatively the corrugation roller and the glue roller can be constructed in sections with the space between the sections in which the fingers can be located. The fingers are attached to a pressure device which allows the fingers to hold the corrugated sheet material against the slat conveyor.

In preferred embodiments the pressure mechanism can be in the form of a vacuum box located within the slat conveyor and configured to apply a vacuum to the slats when they pass through the vacuum box.

The endless belt assembly can be configured to move around a plurality of rollers as is well known in the art. The rollers are arranged so that the belt is held in contact with the coating when the coating and fluted sheet moves around the periphery of the non-fluted belt conveyor assembly which effectively functions as a second corrugating roller.

The fluted endless belt assembly which is formed of a plurality of adjacent slats can be configured in a number of different ways without departing from the scope of the present invention.

In a preferred embodiment the slat conveyor assembly may include one or more flexible tapes to which the slats are attached. The belts move around the rollers and are driven by a drive mechanism as is known in the art.

The glue applicator can take a number of different forms.

Preferably, the glue applicator may be a grooved glue roll which engages (engages) the teeth in the laths. The glue roll that receives the glue from a glue pickup roller and is associated with the glue tray.

However, the glue applicator can be further configured, in other ways substantially as described above.

According to another aspect of the present invention there is provided an apparatus for manufacturing corrugated cardboard on both sides by means of a continuous automated online process wherein the apparatus includes: i) a single-sided corrugator module comprising: - a corrugation roller; - a knurled endless conveyor belt assembly having a surface of the knurled conveyor belt that includes a plurality of adjacent flutes where the flutes are configured to correspond with the teeth in the corrugating roller.; wherein the module is configured so that the sheet material passing between the respective teeth engaging in the corrugation roll and the striated endless conveyor assembly is corrugated and subjected to a first pressure mechanism before entering in contact with a glue applicator and coming into contact with a flat sheet material and with a second pressing mechanism in the form of a tensioned endless belt assembly which holds the respective corrugated and flat sheets together so as to form a joint between them.; ii) a laminating module comprising: two vertically tensioned linear endless belt assemblies which receive between them: a) flat sheet material; Y b) Corrugated sheet material on one side of the corrugator module wherein a glue applicator applies adhesive to the corrugated cardboard on one side and / or to the flat sheet material before it enters the tensioned endless belt assemblies opposite which hold the flat sheet material and the corrugated cardboard on one side together so that a union is formed between them.

According to yet another aspect of the present invention, a joining method is provided for use in the manufacture of corrugated cardboard on one side or on both sides (which are porous) characterized by the steps of using an arrangement of at least a tensioned linear endless belt assembly and an endless belt conveyor assembly for holding the corrugated sheet material together with the flat sheet material so that a joint is formed therebetween.

According to another aspect of the present invention there is provided a method substantially as described above wherein the corrugated sheet material and the flat sheet material are held together for a specific pressure application time calculated by the formula: BT = DHT / RP where RP is the production rate in meters / minute; DHT is the distance in meters to which the two respective sheets are held together; and BT is the bonding time in minutes of the adhesive used and this determines the period of application of pressure.

According to another aspect of the present invention, a single-sided cardboard is provided which has been produced by a method substantially as described above.

According to yet another aspect of the present invention, a double-sided cardboard is provided which has been produced by a method substantially as described above.

According to a further aspect of the present invention there is provided a double-sided cardboard which has been produced from a single-sided board substantially as described above.

According to a further aspect of the present invention there is provided a single-sided cardboard which has been produced from a pre-printed flat sheet that is directly bonded to a corrugated sheet material at an ambient temperature.

According to a further aspect of the present invention there is provided a pre-printed double-sided cardboard which has been produced from a preprinted flat sheet which is directly bonded to a corrugated sheet material forming part of a single-sided cardboard which It occurred at an ambient temperature.

Preferably, the preprinted flat sheet is applied to the single-sided board immediately after it has been formed as part of the automated continuous-line process.

According to a further aspect of the present invention there is provided a double-sided cardboard which has been produced from two pre-printed flat sheets which are bonded directly to the upper and lower surfaces of a corrugated sheet material at an ambient temperature.

It should be understood that the preprinted flat sheets are joined to the corrugated sheet material so that the printed surface (s) are converted to the exposed surface (s) of the single-sided cardboard / double-sided The advantages achieved by the preferred embodiments of the tensioned linear endless belt assembly and the endless conveyor belt assembly may include: provide a way to increase the production rate according to the formula: RP = DHT / BT where RP is the production rate in meters / minute; DHT is the distance in meters to which the two respective sheets are held together; and BT is the union time in minutes.

In particular, the production rate is not limited by X with respect to non-linear corrugators (ie large and small corrugating rollers that mesh) which are determined by the formula C = (RP.BT) / X where C is the circumference of the largest roller (ie n 2r); RP is the production rate in meters / minute and BT is the union time in minutes; and X is the percentage of the circumference around which pressure is applied by the endless belt tensioned. This formula arises from the fact that DHT is equal to X (n 2r). The maximum value of X for the large corrugating roller constitutes a step of limiting the rate - because the diameter of the large corrugating roller can not be increased much more than 2 meters since it would make the roller incredibly heavy. On the contrary, it should be desired that the length of a linear corrugator can be increased easily and almost without limit.

Provide the aforementioned advantages for a cold process over conventional technology to produce not only corrugated cardboard on one side but also on both sides.

The advantages provided by the preferred embodiments of the present invention in relation to both linear and non-linear corrugators also include: - the ability to apply preprinted paper directly to corrugated cardboard as part of a continuous automated online process; the ability to produce corrugated cardboard on one side or on both sides which is completely flat to the naked eye and is not prone to rolling due to the fact that it has been produced in the absence of heat and with a passive braking system for the paper that comes out of the coil.

BRIEF DESCRIPTION OF THE DRAWINGS Other aspects of the present invention will become more apparent from the following description given by means of examples only and with reference to the complementary drawings in which: Figures 1A and IB show the contact portion of the vertex in a schematic lateral elevation of a fluted sheet both before and after joining to the coating; Figure 2 shows a schematic perspective view of part of a corrugation apparatus on one side according to a preferred embodiment of the present invention; Figure 3 shows a perspective view of the corrugation apparatus on one side shown in Figure 2; Figure 4 shows a schematic perspective view of part of a corrugation apparatus on one side according to a further preferred embodiment of the present invention; Figure 5 shows a schematic perspective view of a linear corrugator for producing corrugated cardboard on one side according to a preferred embodiment of a further aspect of the present invention; Y Figure 6 shows a schematic perspective view of an apparatus for manufacturing corrugated cardboard on both sides according to a preferred embodiment of a further aspect of the present invention which utilizes a linear corrugator substantially as shown in Figure 6.

Figure 7 shows a plan view of a cylindrical bar detailed in the embodiment shown in Figure 2.

Figure 8 shows a plan view of a detailed alignment bar in the embodiment shown in Figure 2.

Figure 9 shows a plan view of a detailed convex roller in the tensioned endless belt assembly of the embodiment shown in Figure 2.

Figure 10 shows a schematic perspective view of an apparatus for manufacturing corrugated cardboard on both sides according to a preferred embodiment of a further aspect of the present invention which utilizes a modified linear corrugator with respect to that shown in the Figure 6 Figure 11 shows a portion of a surface of the endless conveyor belt in the form of a conveyor belt made of a plurality of bands in the form of fluted bars.

Figure 12 shows a side view of a fluted bar forming part of the conveyor belt of Figure 11.

Figure 13 shows a cross-sectional view of the ribbed bar of Figure 12.

Figure 14 shows a perspective view of the ribbed bar of Figure 12.

BEST MODES TO CARRY OUT THE INVENTION Figures 1A and IB show a schematic view of a corrugated (scored) sheet of paper (100) illustrating the contact portion of the apex (101).

The contact portion of the apex includes the apex (102) of the raised portions (103) and a region of either side which will abut by the extension of adhesive (104) with the facing sheet (105).

Figures 2 and 3 show a portion of an apparatus for forming a corrugated cardboard on one side known as a corrugation apparatus on one side generally indicated by the arrow (200). The one-sided corrugation apparatus (200) has a smaller first corrugating roller (201) and a second large corrugating roller (202). It will be appreciated for clarity that the rollers (201, 202) shown in the drawings are not shown complete but are incorporated by assembling a series of roller components and placed side by side on an axis (not shown) until the desired width of the roller is achieved.

During operation the porous sheet material in the form of kraft paper (250) is introduced to the corrugating rollers (201) and (202). After passing the rollers (201,202) the kraft paper (250) becomes corrugated sheet material (fluted) (251) The second roller (202) has teeth (203) which engage with the lateral grooves (204) in the surface of a glue applicator roll (GA) (205). The surface of the glue applicator roll (205) picks up the Adhesin ™ Z9040 adhesive from a glue bath (not shown) and the excess glue is removed from the surface by a glue scraper (206) so that only holds adhesive in the slots (204). During use the newly corrugated sheet material (251), which is held by a vacuum to the second roll (202), passes between the second roll (202) and the glue roll (205) so that the contact portion of the vertex (not shown) of the corrugated sheet material is received within the grooves (204) together with the teeth (203) to achieve the transfer of the adhesive towards the vertex contact portion.

At this point the flat sheet material (coating) (260) in the form of kraft paper is inserted between a tensioned endless belt assembly (270) and the second corrugation roll (202) and comes into contact with the contact portions. of the vertex of the corrugated sheet material (251). The tensioned endless belt assembly has an endless belt (271) which applies a specific pressure to the flat sheet (260) to hold it against the corrugated sheet (251). The endless belt (271) applies a specific pressure to 76% of the large roller circumference (20) as indicated by the arrow X. It will be appreciated by those skilled in the art that the sheet material (260) can in some modalities to be preprinted with images and / or texts with high quality graphics.

The tensioned endless belt assembly has a series of rollers (290-294) that apply tension by radially adjusting a tension roller (292) with respect to the axis of the second large corrugation roller (202). During operation the tension in the belt (271) is first adjusted to the point where wrinkle or tear damage usually occurs, of the coating and / or fluted paper. The tension is then reduced by gradually adjusting the tension roller (292) back to a point where damage to the coating / fluted paper does not occur (ie the tension roller is adjusted back to the specified pressure).

The respective sheets (260,251) are held together for a specific time which is determined by the formula: BT = DHT / RP where RP is the production rate in meters / minute; DHT is the distance in meters to which the two respective sheets are held together; and BT is the union time in minutes. Therefore, as can be seen the percentage of 360 ° as indicated by the arrow of two heads X in which the tensioned endless belt comes into contact with the circumference of the roller (20) is critical to determine the distance at which they hold together and therefore the production rate The circumference of the second corrugating roller (202) is determined by the formula: C = (RP.BT) / X where C is the circumference of the roller (i.e. 2r); RP is the production rate in meters / minute; and BT is the union time in minutes and X is the percentage of the circumference around which pressure is applied by the endless belt tensioned.

Therefore, if a production rate of 44 m / min is required and the bonding time of the adhesive is 2s (ie 0.0333 min) the circumference of the second roller is 44x0.0333 which is 1.4666 divided by 76%, which is equal to 1.93 m. This is equal to a diameter of 0.62 m. In other words, the DHT in this example is equal to 2 r multiplied by 0.76%.

The used kraft paper can be recycled or virgin paper and ideally in the order of 90 to 150 gsm.

The second corrugating roller (202) has a network of conduits (not shown) which leads from a vacuum pump not shown to the surface of the roller (not shown) so that a partial vacuum can be created inside the roller of corrugation (202) by means of the vacuum pump. This partial void inside the second corrugation roller (202) holds the fluted sheet (260) in place against the teeth (203) of the second corrugation roller (203).

Also as shown in Figure 2 the apparatus (200) has a first and second alignment system generally indicated by the arrows (500) and (502).

The first alignment system (500) has three cylindrical bars (510-512) which define a zigzag path for the paper (250) coming out of the reel (not shown). The alignment system maintains the paper path (250) straight when it leaves the spool and enters the apparatus (200). The cylindrical bars (510-512) do not rotate but instead impart a frictional force which allows the bars to maintain the straight paper path and prevent any movement to the left or right of the paper when it leaves the reel. To further aid in the alignment of the paper the cylindrical bars (510-512) also have flanged ends (513) (refer to Figure 7) which prevents the paper from getting out of the cylindrical bars and loses alignment with the apparatus (200).

The second alignment system (502) has a first alignment bar (520) which has flared ends (525) (refer to Figure 8) which taper from a cylindrical central section which is the width of the paper (260 ) that comes out of a coil (not shown). The flared ends extend about 50 mm out from the edge of the paper (260) passing over the bar (520). The paper (260) then passes around a cylindrical bar (521) which has flanged ends (refer to Figure 7). The paper (260) then passes to a second alignment bar (522) which has flared ends (refer to Figure 8). Again the bars (520, 521 and 522) are stationary as in the first alignment system (500).

Before entering the apparatus (200) the paper (260) passes over the roller (290) of the tensioned endless belt assembly (270). The roller (290) has a convex outer surface (refer to Figure 9). The inventor has found that the convex outer surface in this roller minimizes the risk of paper accumulating in the center and wrinkling before it enters the apparatus (200) . This accumulation occurs as a result of the paper being redirected towards the center by the second alignment bar (522) whose flared ends prevent any deviation of the paper to the left or right on the bar (522).

It will be appreciated by those skilled in the art that the relative position of the bars relative to one another and the respective coils in the first and second alignment systems (500) and (502) can be adjustable so that the correct pressure can be adjusted. Apply to the paper to keep it aligned with the appliance (200).

During operation the tensioned endless belt assembly (270) by the belt (271) applies pressure to the coating (260) and fluted paper (251) (formerly kraft paper 250), when they travel respectively around 76% of the circumference of the roller (203) as indicated by the arrow X: until the corrugated cardboard on one side (280) is created and leaves the apparatus (200).

It should be appreciated by those skilled in the art that the embodiments with large and smaller corrugation rolls that engage as shown in Figures 2, 3 and 4 can also be used to form a corrugated cardboard on both sides. To do this, the apparatus further includes a two-sided corrugation apparatus (not shown) which is well known in the art.

It will be appreciated, though not shown, that the alignment systems for the paper exiting the reels are also employed in the embodiments depicted in Figures 4, 5 and 6. The alignment systems may be substantially the same as the one that is used. shows and is represented by Figure 2.

Figure 4 shows an apparatus which is similar to that shown in Figures 2 and 3 and therefore similar numeral references have been used to indicate similar elements. The key differences with the embodiment shown in Figure 4 is the fact that the radius of the large corrugation roller (202) is 1 m while in Figures 2 and 3 the large corrugation roller (202) has a diameter of 2. m and the endless belt (271) applies a pressure on 93% of the circumference of the large roller (202) as indicated by the arrow X.

Figure 5 shows an apparatus for manufacturing a corrugated sheet material on one side in the form of a linear corrugator generally indicated by the arrow (300). The apparatus (300) includes a surface of the knurled conveyor belt in the form of an endless conveyor belt assembly (301) which has a plurality of adjacent fluted slats (302) attached to a pair of flexible endless belts ( not shown) which is actuated by a drive mechanism which has a motor (not shown) and a pair of drive pinions (303). The endless conveyor assembly has a number of tube rollers (304) which hold the endless belt (not shown) and the slats (302) on the lower surface at a fixed height relative to a belt assembly without taut end (350). The drive mechanism and the rollers of the tensioned endless belt assembly (350) are not shown since such arrangements are well known in the art.

The endless conveyor belt assembly (301) has a vacuum pump (305) which can apply a vacuum to the recently corrugated sheet material in the form of kraft paper (not shown) which passes between the corrugation roll ( 306) and the endless conveyor belt assembly (301). The openings in the form of slots (307) in the slats (302) allow the vacuum to be imparted on the corrugated kraft paper.

After leaving the corrugation roll 306 the corrugated kraft paper has a controlled amount of adhesive (not shown) applied to the apex contact portions (not shown) of the raised portions (not shown) by a glue roll ( 308) which has a grooved surface (not shown). It should be appreciated that this glue roll 308 may be the same as that described as suitable for, and which is also shown, in the embodiment shown in Figures 2, 3 and 4. The adhesive is taken from a glue tray (not shown) and transferred to the glue roller (308) by means of a glue pick-up roller (309).

The glue roller (308) can preferably be configured to be able to move laterally with respect to the tensioned belt assembly (310) so that it can be adjusted to accommodate a paper of smaller width. [A flat sheet of material in the form of a kraft paper covering (not shown) is inserted between the strip conveyor assembly (301) and the tensioned endless belt assembly (350) at the point indicated by the arrow (310). ). The length (ie the extension) that the slat conveyor assembly (301) and the tensioned endless belt assembly (350) overlap represents the DHT.

As it should be understood, the length of the slat conveyor assembly (301) and the tensioned endless belt assembly (350) can both be extended to increase the production rate according to the formula: RP = DHT / BT.

Figure 6 shows a portion of an apparatus for manufacturing corrugated sheet material on both sides generally indicated by the arrow (400). The apparatus (400) has a corrugation module on one side in the form of a linear corrugator (401) substantially as described above in relation to Figure 5. Therefore, the kraft paper (402) to be corrugated enters the linear corrugator (401) as shown and the kraft paper (403) which will form the liner enters the linear corrugator after passing the glue rollers (407) as shown. The linear corrugator (401) mentioned above is a laminating module in the form of a double-sided corrugation apparatus (404). The double-sided corrugation apparatus 404 has two opposite tensioned endless belt assemblies 405,406 and an assembly of compression rollers and glue applicator 407 through which corrugated cardboard on one side passes before enter the corrugation apparatus on both sides (404). The glue roller assembly (407) is substantially the same as that described in relation to Figure 5. The kraft paper (408) which forms the double-sided coating enters the apparatus (400) and travels along the upper part of the endless belt conveyor (410) of the linear corrugator (401) before it enters the corrugation apparatus on both sides (404) together with the corrugated cardboard on one side at the point indicated by the arrow (409).

It will be appreciated by those skilled in the art that the flat sheet matl used in the embodiments shown in Figures 5 and 6 in some embodiments may be preprinted with images and / or texts with high quality graphics. For example in Figure 6 the flat sheet matl (403) and (408) may be preprinted.

Figure 10 shows a portion of an apparatus for manufacturing corrugated sheet matl on both sides generally indicated by the arrow (1000). The apparatus (1000) has a one-sided corrugation module in the form of a linear corrugator (1001) substantially as described above in relation to Figure 5. The aforementioned linear corrugator (1001) is a laminating module in the form of a corrugation apparatus on both sides (1004). The double-sided corrugation apparatus (1004) has two opposed tensioned endless belt assemblies (1005,1006) and an assembly of compression rollers and glue applicator (1007) through which corrugated cardboard on one side (not shown) produced by the linear corrugator (1001) passes before entg the corrugation apparatus on both sides (1004). The glue roller assembly (1007) is substantially the same as that described in relation to Figure 5. The kraft paper (not shown) which forms the double-sided coating enters the apparatus (1000) and travels along the the upper part of the surface of the grooved conveyor belt (1010) of the linear corrugator (1001) before it enters the corrugation apparatus on both sides (1004) together with the corrugated cardboard on one side at the point indicated by the arrow (1009).

A notable difference with the apparatus shown in Figure 10 on which it is shown and described in Figures 5 and 6 is related to the shape of the conveyor assembly of the linear corrugator (1001). The surface of the endless conveyor belt (1010) is formed of fluted bars (1011) - as shown in Figure 11 opposite to the fluted slats as shown in Figure 5 - which are again arranged to form a belt without end. The splined bars (1011) have connecting portions in the form of a pair of openings (1012) at either end thereof which can receive pins (not shown) to join the adjacent bars (1011) with respect to each other to form the tape (1010). The fluted bars (1011) are shown in more detail in Figures 12-14 and in particular the fluted upper surface (1012) of the bar (1011).

The linear corrugator (1001) has a belt (1010) driven by the rotation of the corrugating roller (1020) (by a motor not shown) so that the teeth of the roller (1021) engage with the grooves (1012) of the bars (1011) to move the ribbon (1010). In addition, additional movement to the belt can be imparted by the sprockets (1015) which are driven by a separate motor (not shown) so that the teeth (1016) can be coupled with pins connecting the bars (1011) through the spaces (1017) between the laterally adjacent bars (1011) on the tape (1010). The spaces (1017) also facilitate the application of a vacuum through the conveyor belt in a manner similar to that described above in relation to Figure 5.

EXAMPLE 1 To calculate the production rate for a second corrugation roll of 1.6 m in diameter (ie large) where the endless belt extends 76% around the second roll applying the new formula of the present invention RP = DHT / BT this is equal to an RP (production rate) of 0.76 (1.6) /0.05 which is equal to the production rate of 76 m / min where 0.05 minutes is a union time of 3 seconds. This production rate is significantly lower than that calculated by the applicant in WO2009 / 000085.

EXAMPLE 2 If a manufacturer requires a production rate which is 143 m / min using an adhesive having a BT of 0.033333 min (ie 2s) the diameter of the second corrugating roller (i.e. larger) by applying the new formula of the present invention DHT can be represent as 0.93x (2r) and the diameter can be calculated from DHT = RP.BT that would be (143 x 0.033333). Then to obtain the diameter the equation 0.93x (2r) = (143 x 0.033333) is reorganized so that 2r (ie the diameter) = ((143 x 0.033333) / 0 .76) / which is equal to a diameter of 2 m.

EXAMPLE 3 If you want to calculate the production rate for a roll of 2 m in diameter where the BT is 0.05 min (ie 3 s). The formula RP = DHT / BT 0.93 (2) / 0.05 is applied which is equal to 116 m / min.

In practice a diameter of 2 m is at or near the limit at which corrugated cardboard can be created by a pair of interlocking corrugation rolls: such as those described herein, shown in Figure 2 or as described in FIG. the previous PCT application WO2009 / 145642 of the applicant. One reason why in practice it is not possible to have a large corrugation roller with a diameter significantly greater than 2 m (for example a 2.5 m roller, 3 m or larger diameter) is because the increased weight of such a roller makes difficult to drive and move it particularly during the construction, maintenance and repair of such a large roller. In addition, the increased weight of a roller with a diameter greater than 2 m requires significantly more energy to rotate the roller and therefore increases the production cost. In addition there are problems to maintain a vacuum inside such a large roller and again more energy is required to achieve it. For these reasons any increase in the production rate achieved by a large corrugation roll having a diameter of more than 2 m has been found by the applicant to be effectively negative for the aforementioned problems.

EXAMPLE 4 A non-linear corrugator similar to that shown in Figure 4 can produce corrugated cardboard on one side at rates faster than those mentioned in the previous examples even though the bonding times of the adhesive are the same. For example to have a rate of 200 m / min where the BT is 0.033333 minutes would require an endless belt conveyor that overlaps with an endless belt assembly tensioned by a length of 6.6 m. According to the formula RP = DHT / BT.

The aspects of the present invention were described by way of example only and it will be appreciated that modifications and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims

A method for joining a substantially flat sheet material to a corrugated sheet material which becomes porous using a continuous process, the method characterized by the steps of: a) applying a controlled amount of adhesive to the vertex contact portion of the corrugated sheet material; Y b) holding the respective corrugated and flat sheets together at a specific pressure and during a specific pressure application period so that a joint is formed between them.
A method as claimed in claim 1 wherein steps a) and b) are carried out at room temperature.
A method as claimed in claim 1 or claim 2 wherein the period of application of specific pressure refers to the binding time (BT) calculated by the formula: BT = DHT / RP where RP is the production rate in meters / minute and DHT is the distance in meters at which the two respective sheets are held together.
A method for joining a substantially flat porous sheet material to a corrugated porous sheet material using a continuous process as claimed in claim 1 wherein the production rate has been calculated by the formula: RP = DHT / BT where RP is the production rate in meters / minute; DHT is the distance in meters for which the two respective blades are held together; and BT is the bonding time of the adhesive in minutes.
A method for manufacturing an apparatus having large and small corrugating rollers that mesh to continuously produce a porous sheet material on one side comprising the step of using the formula: RP = DHT / BT to determine the diameter of the large corrugating roller and the percentage of the circumference of the large corrugating roller around which an endless belt assembly is needed to apply pressure so as to achieve the desired production rate; where RP is the production rate in meters / minute; DHT is the distance in meters for which the two respective blades are held together; and BT is the bonding time of the adhesive in minutes.
An apparatus which attaches the substantially flat porous sheet material to the corrugated porous sheet material, to produce a corrugated porous sheet material on one side as part of a continuous process which utilizes a large corrugation roll and an applicator assembly. glue and smaller corrugator roller together with an endless belt tensioned, where the production rate of the apparatus has been determined by the formula: RP = DHT / BT where RP is the production rate in meters / minute; DHT is the distance in meters to which the two respective sheets are held together; and BT is the bonding time of the adhesive in minutes.
An apparatus which attaches a substantially flat porous sheet material to a corrugated porous sheet material, to produce a corrugated porous sheet material on one side by a continuous process, wherein the apparatus includes a large diameter corrugation roll that is gear with a smaller diameter corrugation roll, and a tensioned endless belt assembly is arranged to apply pressure on the circumferential surface of the large corrugation roll to facilitate the rolling of the corrugated and flat sheets where the circumference of the roll of Large diameter corrugation around which the endless belt can apply tension is determined by the formula: C = (RP.BT) / X where C is the circumference of the roller (ie n 2r); RP is the production rate in meters / minute and BT is the union time in minutes; and X is the maximum percentage of the circumference around which pressure can be applied by the endless belt tensioned.
An apparatus which attaches a substantially flat porous sheet material to a corrugated porous sheet material to form corrugated porous sheet material on one side by a continuous process wherein the apparatus includes a large diameter corrugation roll that meshes with a smaller diameter corrugation roll, and a tensioned endless belt assembly which includes a tensioned belt arranged to apply pressure on the circumference of the large corrugation roller to facilitate the rolling of the corrugated and flat sheets where the percentage of the circumference of the large corrugation roll which does not have the tape tensioned by applying pressure to it is limited only by the relative minimum space required for the assembly of the glue applicator and smaller corrugating roller.
A method for operating a large diameter corrugation roll that meshes with a smaller diameter corrugation roll and a tensioned endless belt comprising a pressure stage in which the tensioned tape is arranged to apply pressure on a portion of the circumferential surface of the large corrugation roll to form an adhesive bond between a substantially flat porous sheet material and a corrugated porous sheet material comprising the additional step of using the percentage of the length of tape on the circumference of a corrugation roll larger to determine the production rate.
A method for using a tensioned tape and a large diameter corrugation roll that meshes with an assembly of the glue applicator and smaller diameter corrugation roll to produce corrugated cardboard on one side from a flat porous sheet material and a corrugated flat sheet material, the method comprising the steps of applying an adhesive to the corrugated sheet material, at an ambient trature, and then holding the respective corrugated and flat sheets together by the tensioned tape, for a specific period of time.
A method as claimed in claim 1 which utilizes a large corrugating roller and a tensioned endless belt where the maximum production rate is determined by the formula: RP = X (n2 r) .BT where RP is the production rate in meters / minute, BT is the union time in minutes, and X is the percentage of the circumference of the large corrugation roll around which pressure is applied by the endless belt tensioned.
A method as claimed in claim 10 wherein the maximum production rate is determined by the formula: RP = X (n2 r) .BT where RP is the production rate in meters / minute, BT is the union time in minutes, and X is the percentage of the circumference of the large corrugation roll around which pressure is applied by the endless belt tensioned.
An apparatus as claimed in claim 7 wherein the tensioned endless belt is configured so that the belt can apply pressure on 70% -93% of the circumference of the large corrugation roll.
A method for attaching a substantially flat sheet material to a corrugated sheet material which becomes porous using an automated process, the method characterized by the steps of: a) applying adhesive to the corrugated sheet material with a glue application roll (GA) which has left and right side grooves on the circumference of the roll GA which engage with the teeth in the corrugation roll where said grooves in the GA roll hold an established amount of glue in them b) holding the respective corrugated and flat sheets together at a specific pressure and for a specific time so that a joint is formed between them.
15. A method for joining as claimed in claim 14 wherein the dimensions of the grooves in the GA roller allow a line of adhesive held in them; the teeth (or a portion thereof) on the corrugation roll and the vertex contact portion of the corrugated sheet are received therein; so that a line of adhesive can be applied to the vertex contact portions of the corrugated sheet.
An apparatus for making corrugated cardboard on one side by joining a corrugated sheet material having one or more raised portions on a substantially flat sheet, which are porous,: the apparatus including an applicator configured to apply adhesive to each raised portion of the corrugated sheet material, and a pressure mechanism to press the flat sheet against the elevated portion of the corrugated material wherein the applicator is configured to apply a controlled amount of adhesive to the vertex contacting portions in each raised portion of the corrugated sheet material and wherein the pressing mechanism is configured to press the sheet material flat against the sheet material corrugated at a specific pressure for a specific time so that a union is formed between them.
An apparatus which attaches substantially flat porous sheet material to a corrugated sheet material by a continuous process wherein the apparatus includes a large corrugation roll which meshes with a small corrugation roll where the diameter of the smaller roll is at least substantially between 0.16 m-0.2 m and the large corrugating roller has a diameter of at least substantially between 0.4 m-2.0 m.
18. An apparatus as claimed in claim 8 wherein the apparatus operates at a maximum production rate determined by the formula: RP = X (n2 r). BT where RP is the production rate in meters / minute, BT is the union time in minutes, and X is the percentage of the circumference of the large corrugation roll around which pressure can be applied by the endless belt tensioned.
19. The use of the principle: RP = DHT / BT in the construction of single-sided cardboard manufacturing facilities; where RP is the production rate in meters / minute; DHT is the distance in meters for which the two respective blades are held together; and BT is the bonding time of the adhesive in minutes.
20. A use of a water-based adhesive in the production of single-sided cardboard.
21. The use of claim 20 wherein the adhesive is a vinyl acetate copolymer containing dispersion.
22. An apparatus for manufacturing a corrugated sheet of a face of porous material by an automated process wherein the apparatus includes: a corrugation roller; a contoured roller for applying discrete glue drops to the raised portions of freshly corrugated sheet material. a knurled endless conveyor belt assembly having a surface of the knurled conveyor belt that includes a plurality of adjacent flutes wherein the flutes are configured to correspond with the teeth in the corrugating roller. a pressure mechanism configured to hold freshly corrugated sheet material to the surface of the knurled conveyor belt while applying an adhesive by means of a glue applicator; a tensioned endless belt assembly which holds the flat sheet material and the corrugated sheet material together so that a joint is formed between them; wherein the pressure mechanism is in the form of a vacuum pump and wherein the vacuum pump is positioned only at the front end of the non-grooved conveyor belt assembly. An apparatus to manufacture corrugated cardboard on both sides by means of a continuous automated online process where the apparatus includes: i) a single-sided corrugator module comprising: a corrugation roller; a knurled endless conveyor belt assembly having a grooved conveyor surface that includes a plurality of adjacent flutes where the flutes are configured to correspond with the teeth in the corrugation roll a pressure mechanism configured to hold the newly corrugated sheet material to the surface of the fluted belt while applying an adhesive by means of a glue applicator; wherein the pressure mechanism is in the form of a vacuum pump and wherein the vacuum pump is positioned only at the front end of the non-grooved conveyor belt assembly; wherein the module is configured so that the sheet material passing between the respective teeth engaging in the corrugation roll and the striated endless conveyor assembly is corrugated and subjected to a first pressure mechanism before entering in contact with a glue applicator in the form of a contoured roller and in contact with a flat sheet material and with a second pressing mechanism in the form of a tensioned endless belt assembly which holds the respective corrugated and flat sheets together so that a union is formed between them; ii) a laminating module comprising: - two assemblies of endless linear tape tensioned vertically opposite which receive between them: a) the flat sheet material; Y b) Corrugated sheet material on one side from the corrugator module wherein a glue applicator in the form of a contoured roller applies adhesive to the corrugated cardboard on one side and / or flat sheet material before it enters the tensioned endless belt assemblies opposite which hold the flat sheet material and the corrugated cardboard on one side together so that a joint is formed between them. A joining method for use in the manufacture of corrugated cardboard on one side or on both sides (which are porous) characterized by the steps of using an arrangement of at least one tensioned linear endless belt assembly and an assembly of endless belt conveyor strips to hold the corrugated sheet material together with the flat sheet material so that a joint is formed between them. A method as claimed in claim 24 wherein the corrugated sheet material and flat sheet material are held together for a specific pressure application time calculated by the formula: BT = DHT / RP where RP is the production rate in meters / minute; DHT is the distance in meters to which the two respective sheets are held together; and BT is the bonding time in minutes of the adhesive used and this determines the period of application of pressure. A corrugated sheet material produced by any of the method or machines of the preceding claims.