Methods and equipment for manufacturing corrugated cardboard

Abstract

This invention discloses a method for manufacturing corrugated cardboard. The method includes: guiding a corrugated base paper from a corrugated base paper supply roll to a pair of corrugated rolls; and operating the pair of corrugated rolls to wrinkle the corrugated base paper; wherein each corrugated roll is operated at ambient temperature; wherein the step of operating the pair of corrugated rolls to wrinkle the corrugated base paper includes forming a groove web, wherein the corrugated base paper substantially conforms to a plurality of corrugator peaks and is spaced from a plurality of corrugator grooves of at least one of the pair of corrugated rolls.

Description

Technical Field

[0001] This invention relates to a method for manufacturing corrugated cardboard, an apparatus for manufacturing corrugated cardboard, and corrugated cardboard manufactured using the apparatus and / or method. Background Technology

[0002] Corrugated cardboard (sometimes called corrugated board or simply board) is used worldwide to produce cardboard boxes and pallets, providing inexpensive and practical packaging for a wide variety of goods.

[0003] However, due to the cost and size of the manufacturing equipment, only a few large, expensive factories produce corrugated cardboard and then ship it to the point of use. Although individual sheets of corrugated cardboard are not very heavy, the cardboard has a large volume due to its corrugated nature, and therefore the cost of shipping it to the individual factories used for packaging goods is disproportionately high. The carbon footprint associated with the shipment of corrugated cardboard also has an adverse environmental impact.

[0004] A typical existing paperboard manufacturing apparatus typically consists of a single-facer unit, a conveyor bridge, and a double-facer unit. A corrugated base paper (usually referred to as paper) is supplied from a supply roller conveniently located near the single-facer unit. Similarly, a further supply roller supplies an inner liner (again usually paper) to the single-facer unit. The inner liner is so named because it is typically configured to form an inner surface of a cardboard box / pallet.

[0005] Paper typically first passes through a series of rollers that are often heated to a temperature above 100 degrees Celsius (e.g., 140 degrees Celsius). This ensures that moisture is removed by evaporation, allowing the paper to be supplied in a consistent state before entering the single-facer or double-facer unit. Additionally, the heated rollers are used to heat the paper to enhance its elasticity.

[0006] Next, before the corrugated base paper is fed between a pair of corrugating rolls, directly applied steam is used to condition the paper, making it moist and flexible. The two corrugating rolls are also heated, often to a temperature above 100 degrees Celsius (e.g., 140 degrees Celsius). Heat helps maintain the flexibility of the corrugated base paper as it bends into corrugations. The corrugating rolls have interlocking teeth (similar to gear meshing) that cause the corrugated base paper to wrinkle. That is, the paper is forced into the gaps between the interlocking ridges of the corrugating rolls (sometimes called a labyrinth) to form a corrugated layer.

[0007] The corrugated layer is sometimes referred to as the fluted web, fluted pad, or corrugated pad, and the ridge of the fluted web is sometimes referred to as the column flute.

[0008] Due to the flexibility of the freshly heated and evaporated corrugated base paper, the paper remains in its proper position as the large corrugated rolls rotate. Next, a gluing station provides a thin layer of starch glue to the outer ridges or grooves of the web.

[0009] Gluing stations often have a glue bath with a roller that is in constant contact with the glue surface, so that a thin layer of glue is transferred onto the roller as it rotates. Then, the glue is transferred from the roller directly or via an intermediate transfer roller to the trough web.

[0010] The inner liner is fed onto the glued layer of the corrugated web by a series of rollers (which can be heated), where it is bonded to the outer ridge. This assembly of the corrugated base paper bonded to the inner liner is commonly referred to as a single-face web. The single-face web, which has poor rigidity, is fed to the conveyor bridge.

[0011] The conveyor bridge typically operates at a step speed lower than the output of the single-facer unit, allowing the single-facer web to form a loop on the conveyor bridge to handle any slack in the single-facer web. The adhesive between the trough web and the inner liner must dry on the conveyor bridge before the single-facer web is fed to the double-facer unit.

[0012] The double-sided machine unit glues an outer liner to a single-sided web to provide the final double-sided face. Starch adhesive is supplied from a second gluing station to the exposed ridges or grooves of the web opposite the inner liner. A further roller supplies an outer liner to the double-sided machine unit. The outer liner is fed through a series of rollers (which can be heated) and contacts the glued side of the single-sided web.

[0013] The double-sided panels are then dried and cooled to provide a three-layer laminate, which is then cut into any desired shape for use.

[0014] Existing creping processes are typically very long, reaching 100 meters or more. A conveyor bridge allows for a buffer between single-facer and double-facer units, enabling one or the other unit to stop or slow down for a short period without stopping / slowing down the other unit. In this case, the amount of loops stored in the single-facer web on the conveyor bridge increases or decreases.

[0015] For example, if a new paper roll needs to be installed on a double-facer unit, the double-facer unit speed can be reduced when the paper roll is changed. During this time, the single-facer unit remains constant, and therefore the number of loops accumulated on the conveyor bridge increases. Similarly, if the paper roll is changed on a single-facer unit, the number of loops stored in the single-facer web on the conveyor bridge will decrease.

[0016] Therefore, the total amount of paper on the conveyor bridge, and consequently the length of time a single web spends on the bridge, can vary dramatically depending on the latest history of the equipment.

[0017] To ensure the starch adhesive between the inner liner and the web dries, the conveyor bridge must be very long to guarantee that the single-sided web is completely dry and arrives at the double-sided machine unit under consistent conditions. Of course, the single-sided web will lose heat at this point and must be pre-conditioned using a heater unit before being fed to the double-sided machine unit, requiring further energy input.

[0018] Existing corrugated cardboard manufacturing equipment has many drawbacks.

[0019] The equipment is too large to be used at the point of use and requires a dedicated large-scale manufacturing facility and a large workforce to keep it running. This in turn means that bulky corrugated cardboard needs to be transported to the point of use, which is both expensive and environmentally unfriendly.

[0020] Providing heat to the corrugated base paper before creping requires a large steam boiler to supply enough steam to heat the large manufacturing volume. This necessitates very high energy consumption and further increases the size of the facilities required to house the equipment.

[0021] After cooling on the conveyor bridge, the single-sided web requires reheating and further energy input.

[0022] The unstretched single-sided web is left to dry on the conveyor belt and is therefore susceptible to varying drying conditions, depending on atmospheric conditions. Consequently, warping and shrinkage of the single-sided web, as well as variations and irregularities in the grooves, can occur.

[0023] For all the reasons mentioned above, the productivity and efficiency of existing corrugated board production lines are not as high as they appear. Furthermore, they do not produce the consistently high-quality corrugated boards as expected.

[0024] The goal is to reduce the size of the equipment to allow for installation at the point of use.

[0025] Further efforts are expected to reduce energy consumption during the manufacturing of corrugated cardboard to lower production costs and reduce environmental impact.

[0026] It is also desirable to produce consistent products with no (or minimal) warping or corrugation and increased strength for the same weight of paper.

[0027] Therefore, an objective of the present invention is to provide a method and apparatus for manufacturing corrugated cardboard that solves one or more of the above problems or provides at least one useful alternative. Summary of the Invention

[0028] To address the aforementioned problems related to the prior art, the present invention avoids the use of heat or steam in the manufacture of one-groove webs of corrugated cardboard and provides a compact corrugated cardboard manufacturing apparatus.

[0029] Specifically, the present invention relates to the manufacture of corrugated board using a cold (unheated) corrugating machine (which at least achieves and includes the formation of a flute web). In some embodiments, heat is not used anywhere in the process of manufacturing the corrugated board. In some embodiments, heat is not used when forming a flute web, although heat may be used for glue drying (e.g., via an infrared (IR) heater) after the flute web is glued to a first liner and / or a second liner. Therefore, heat is not used to condition the corrugated base paper.

[0030] According to one aspect of the present invention, a method for manufacturing corrugated cardboard is provided, the method comprising:

[0031] Guide a corrugated base paper from a corrugated base paper supply roll to a pair of corrugated rolls; and

[0032] Operate the pair of corrugated rollers to wrinkle the corrugated base paper;

[0033] Each corrugated roller operates at ambient temperature.

[0034] Therefore, embodiments of the present invention provide a cold corrugating machine in which heat is not required to produce consistently high-quality, high-strength corrugated cardboard.

[0035] The ambient temperature is understood to be a natural ambient temperature, meaning that no active heating or cooling is applied to the corrugating rolls during the corrugation process in the corrugated base paper. Therefore, a typical ambient temperature can be room temperature, which may vary between approximately 0 degrees Celsius and approximately 60 degrees Celsius depending on the location of the equipment and the local environment.

[0036] In addition, heat may not be applied to the corrugated base paper before the corrugation is formed.

[0037] This method can also be steam-free. That is, neither the corrugated base paper nor the web of the flute becomes damp by steam and therefore can be considered dry.

[0038] The step of operating the pair of corrugating rolls to crease the corrugated base paper may include forming a groove web, wherein the corrugated base paper substantially conforms to a plurality of corrugator peaks and is spaced from a plurality of corrugator grooves in at least one of the pair of corrugating rolls. This places less strain on the corrugated base paper to ensure that the paper does not tear even in the absence of heat and moisture. It may also help to provide a larger, flatter surface area at the peaks of the groove for more effective adhesion to a backing paper.

[0039] Operating the pair of corrugating rolls may include spacing the pair of rolls and / or applying pressure such that when the pair of rolls are engaged, the corrugator peak of the first roll is spaced apart from the corrugator groove of the second roll. As described above, this places less strain on the corrugated base paper to ensure that the paper does not tear even in the absence of heat and moisture.

[0040] At least one of the pair of corrugated rolls may include a series of corrugations having a height at least 10% greater than a target groove height of the corrugated base paper. This similarly ensures that the cold corrugated base paper does not tear as it passes through the pair of corrugated rolls.

[0041] At least one of the corrugating rolls may include a series of corrugations having a height pitch ratio of at least 0.5. This ratio is larger than that of a conventional corrugator with a height pitch ratio of about 0.4. This feature also helps to ensure that the paper does not need to meet the base of the corrugator flute to form a desired flute height, which further reduces the risk of tearing cold corrugated base paper.

[0042] At least one of the corrugated rolls may include a series of corrugations having a height pitch ratio of at least 0.6. In some cases, the height pitch ratio may be approximately 0.65.

[0043] The corrugated base paper supply roll can operate at ambient temperature. In fact, no part of the equipment requires heat during use, thus providing significant energy savings and allowing for the use of a more compact device to perform the method. In some embodiments, no heat may be applied to condition the corrugated base paper before corrugation. In some embodiments, no heat may be applied to any roll.

[0044] The ambient temperature can be below 60 degrees Celsius. In some examples, the ambient temperature may be below 50 degrees Celsius, below 40 degrees Celsius, below 30 degrees Celsius, below 20 degrees Celsius, or below 10 degrees Celsius.

[0045] When the paper passes through the pair of corrugating rolls, the corrugated base paper can have a moisture content consistent with environmental conditions. In other words, it is not necessary to apply moisture or vapor to the corrugated base paper. This is because the equipment is configured to form the corrugations in such a way that it places less strain on the corrugated base paper (e.g., by not pressing the paper against the base of the corrugator trough) so that it is not necessary to add moisture to make the paper flexible.

[0046] This method may include manufacturing corrugated cardboard without using a heat source. Therefore, significant energy savings are provided. In some embodiments, at least the method comprising forming a fluted web may not employ a heat source. In some embodiments, heat will not be used when forming a fluted web, although heat may be used for glue drying (e.g., via an infrared (IR) heater) after the fluted web is glued to a first liner and / or a second liner.

[0047] This method may include manufacturing corrugated cardboard without using steam. Some advantages believed to be that not using steam will allow the paper to better retain its strength and may result in a reduced tendency to warp.

[0048] The method may further include employing a vacuum system to hold the corrugated base paper on one of the pair of corrugating rolls to a predefined portion of rotation during creping into a grooved web. This vacuum helps to hold the grooves of the web in place against the elastic force that causes the cold paper to spring back into a flattened configuration.

[0049] The method may further include joining a first pad to a first side of the groove web to form a single-sided web while holding the groove web on one of the pair of corrugated rolls by means of the vacuum system. This ensures that the groove remains in a desired configuration when the pad is joined in place. A heat source may be used to accelerate the joining process (e.g., when the groove web is held on one of the pair of corrugated rolls). However, this heat source (if provided) will be directed to the paper after creping has occurred. Furthermore, this heat source will be located outside (not inside) the pair of corrugated rolls. Therefore, heat from this heat source will be directed to an outer surface of the first pad and the groove web.

[0050] The method may further include joining a second liner to a second side of the web of the groove to form a double-sided web. As described above, a heat source may be provided to accelerate the joining process of the second liner.

[0051] Bonding can be achieved using a thermoplastic adhesive (such as, for example, polyvinyl acetate (PVA) adhesive or polyethylene adhesive). Bonding can also be achieved using a water-based adhesive. Bonding can also be achieved using a non-carbohydrate-based adhesive. These adhesives are superior to starch adhesives, which significantly wet the web and gaskets, making them more prone to tearing, increasing drying time, and reducing the overall strength of the plate. PVA adhesives (for example) are less wet and cure rapidly at ambient temperature, further reducing the need for heat.

[0052] According to a second aspect of the invention, a corrugated board manufactured by the above-described method is provided. Compared to corrugated board manufactured using conventional methods, this corrugated board is stronger for the same weight of paper because it is believed that the absence of heat and steam (at least during corrugation formation) ensures that the paper strength is maintained throughout the manufacturing process, resulting in a lower tendency for corrugated board warping. Furthermore, the flutes of this corrugated board can be uniform and have larger and flatter peaks, which provides a better surface for bonding and results in fewer corrugations. The application of PVA adhesive (or similar materials) also ensures a stronger bond with the insulator. The increased strength per sheet weight also means that a lower weight of paper can be used to provide a given strength for the corrugated board, which can lead to a reduction in the amount of material required, which is better for the environment.

[0053] According to a third aspect of the present invention, an apparatus for manufacturing corrugated cardboard is provided, the apparatus comprising:

[0054] A pair of corrugating rolls configured to wrinkle a corrugated base paper when operating at ambient temperature.

[0055] The pair of corrugated rolls can be configured to operate such that when the pair of corrugated rolls are engaged together, the corrugating peak of the first roll is spaced apart from the corrugating groove of the second roll.

[0056] At least one of the corrugated rolls may include a series of corrugations having a height at least 10% greater than a target groove height of the corrugated base paper.

[0057] At least one of the corrugated rolls may include a series of corrugations having a height pitch ratio of at least 0.5.

[0058] At least one of the corrugated rolls may include a series of corrugations having a height pitch ratio of at least 0.6.

[0059] The device may further include a corrugated base paper supply roller configured to guide a corrugated base paper to the pair of corrugated rollers, wherein the corrugated base paper supply roller is configured to operate at ambient temperature.

[0060] The equipment can be configured to manufacture corrugated cardboard without using a heat source, at least achieving and including the formation of a grooved web.

[0061] The equipment can be configured to manufacture corrugated cardboard without using steam.

[0062] The device may further include a vacuum system configured to hold the corrugated base paper on one of the pair of corrugated rolls to a predefined portion of rotation as it is creased into a grooved web.

[0063] The device may further include a first joining assembly configured to join a first liner to a first side of the grooved web to form a single-sided web while the grooved web is held on one of the pair of corrugated rolls by the vacuum system.

[0064] The device may further include a second joining assembly configured to join a second liner to a second side of the slot web to form a double-sided web.

[0065] The first engagement assembly and / or the second engagement assembly may include a pressure roller and wherein the pressure roller is configured to operate at ambient temperature.

[0066] The ambient temperature can be below 60 degrees Celsius.

[0067] According to a fourth aspect of the present invention, a corrugated cardboard manufactured using the above-described equipment is provided. Attached Figure Description

[0068] Some embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, wherein:

[0069] Figure 1 A schematic diagram of an apparatus for manufacturing corrugated cardboard according to the present invention is shown.

[0070] Figure 2 Showing through Figure 1 An enlarged view of the corrugated base paper of the equipment's corrugated roller.

[0071] Figure 3 As shown Figure 1 An exploded view of a gluing station used in the equipment.

[0072] Figure 4 A method for manufacturing corrugated cardboard according to the present invention is illustrated.

[0073] Figure 5A and Figure 5B A plan view and a side view of a piece of corrugated cardboard manufactured according to the present invention are shown respectively. Detailed Implementation

[0074] Generally, the present invention provides an apparatus and method for manufacturing corrugated cardboard without using heat, which at least achieves and includes forming a grooved web.

[0075] The attached figures show some examples of solutions.

[0076] Figure 1 An apparatus 100 for manufacturing corrugated cardboard according to the present invention is shown. The apparatus 100 includes a pair of corrugating rollers 102a and 102b configured to crease a corrugated base paper 104 when operating at ambient temperature (e.g., without active internal heating or cooling). The corrugated base paper 104 is a large sheet of paper disposed on a corrugated base paper supply roller 106. Figure 1 As shown, the corrugated base paper 104 is guided to the first corrugated roll 102a via a guide roller 108a. However, in other embodiments, the corrugated base paper 104 may be guided directly from the corrugated base paper supply roller 106 to the first corrugated roll 102a, or any number of guide rollers may be provided in the path of the corrugated base paper 104. The corrugated base paper supply roller 106 and the guide roller 108a also operate at ambient temperature (e.g., without internal heating).

[0077] The corrugated base paper 104 is forced between the meshing teeth of the pair of corrugated rolls 102a and 102b to form a corrugated web 110, as described below relative to... Figure 2This will be described in more detail. Corrugating rolls 102a and 102b are configured to pull corrugated base paper 104 from corrugated base paper supply roll 106 to form a web 110. A vacuum force applied from inside the corrugating roll 102b holds the web 110 on the corrugating roll 102b so that air is drawn inward along with the corrugated base paper 104 through small holes (not shown) in the outer surface of the corrugating roll 102b. The vacuum force holds the web 110 on the corrugating roll 102b to a predefined portion of rotation and ensures that the web 110 contacts a bonding agent from a first bonding station 112a before being bonded to a first pad 114 via a first pressure roll 116a. In summary, the first bonding station 112a and the first pressure roll 116a can be considered as a first bonding assembly configured to bond the first pad 114 to a first side of the web 110 to form a single-sided web 120.

[0078] The first pad 114 is a large sheet of paper disposed on a first pad supply roller 118. For example... Figure 1 As shown, the first pad 114 is guided to the first pressure roller 116a via two guide rollers 108b and 108c. However, in other embodiments, the first pad 114 may be guided directly from the first pad supply roller 118 to the first pressure roller 116a, or any number of guide rollers may be provided in the path of the first pad 114. The first pad supply roller 118 and the guide rollers 108b and 108c also operate at ambient temperature.

[0079] The adhesive can be a thermoplastic, such as polyvinyl acetate (PVA) adhesive. This is better than starch adhesives, which significantly wet the web and gaskets, making them easier to tear, increasing drying time, and reducing the overall strength of the plate. On the other hand, PVA adhesive is less wet and can cure quickly at ambient temperature, further reducing the need for heat.

[0080] Next, the single-sided web 120 is guided from the corrugated roller 102b to a second joining assembly configured to join the second pad 122 to a second side of the grooved web 110 to form a double-sided web 126. The second joining assembly includes a second joining station 112b and a second pressure roller 116b. In an embodiment, Figure 1 A guide roller 108d is shown disposed between the second joining station 112b and the second pressure roller 116b. In other embodiments, a guide roller may not be required between the second joining station 112b and the second pressure roller 116b, or multiple guide rollers may be provided. Additionally, in this embodiment, no guide roller is provided between the corrugated roller 102b and the second joining station 112b. In other embodiments, one or more guide rollers may be provided between the corrugated roller 102b and the second joining station 112b.

[0081] The second pad 122 is a large sheet of paper disposed on the second pad supply roller 124. For example... Figure 1 As shown, the second pad 122 is guided directly to the second pressure roller 116b. However, in other embodiments, the second pad 122 may be guided to the second pressure roller 116b via one or more guide rollers. The second pad supply roller 124 and the guide roller 108d also operate at ambient temperature.

[0082] In some embodiments, the second liner 122 may not be required and the output from the device 100 may be a single-sided web 120. In other words, the second coupling assembly may not be required.

[0083] In some embodiments, the apparatus 100 may be configured to produce corrugated cardboard having multiple layers of corrugated material and / or padding material by means of feeding a single-sided web 120 or a double-sided web 126 with an additional device configured to join additional layers in a manner similar to that described above.

[0084] like Figure 1 As shown, the device 100 can be relatively compact. Advantageously, each corrugated roll 102a, 102b is configured to operate at an ambient temperature that can be below 60 degrees Celsius. This significantly reduces the complexity of the device 100 and its energy consumption compared to systems that require heating the corrugated rolls (which are often heated to above 100 degrees Celsius (e.g., 180 degrees Celsius)). Furthermore, heating any components of the device 100 may be unnecessary, further reducing energy consumption.

[0085] Furthermore, no steam is needed to wet the corrugated base paper 104 to make it more flexible before forming the web 110. This further reduces energy consumption and eliminates the need for long drying times, thereby allowing the equipment 100 to be compact. In addition, the absence of steam means that the corrugated board is less prone to warping, as this is believed to be caused by the different drying times in different areas of the corrugated board.

[0086] Although corrugated rollers 102a and 102b are in Figure 1 The figures are shown as approximately the same size, but this is not necessary. In fact, it may be advantageous for a first (e.g., lower) corrugating roll 102a to have a smaller diameter than the second (e.g., upper) corrugating roll 102b, as this reduces the number of engaging corrugations, which helps prevent tearing of the corrugated base paper (e.g., because less paper is stretched during corrugation). In one example, the first corrugating roll 102a may have a diameter of approximately 120 mm, while the second corrugating roll 102b may have a diameter of approximately 550 mm. More generally, the diameter of the first corrugating roll 102a may be 10%, 20%, 25%, 30%, 40%, 50%, 60%, or 75% smaller than the diameter of the second corrugating roll 102b. Advantageously, the second corrugating roll 102b is the larger of the pair of corrugating rolls to allow for a longer drying time when glue is deposited on the corrugated base paper.

[0087] Figure 2Shown in Figure 1 An enlarged view 200 shows the corrugated base paper 104 passing between the corrugations in the corrugating rolls 102a and 102b of the equipment 100. As illustrated, the corrugated base paper 104 substantially conforms to the corrugator peaks 202a and 202b and is spaced from the corrugator grooves 204a and 204b in each of the corrugating rolls 102a and 102b. This configuration can be attributed to the spacing between the pair of corrugating rolls 102a and 102b and / or to the application of a predefined pressure on at least one of the corrugating rolls 102a and 102b such that when the pair of corrugating rolls 102a and 102b are engaged together, the corrugator peak 202a of the first roll 102a is spaced apart by a distance s from the corrugator groove 204b of the second roll 102b.

[0088] In some embodiments, at least one of the corrugating rolls 102a and 102b may have a series of corrugations having a height h from the corrugator slots 204a and 204b to the corrugator peaks 202a and 202b, the height h being at least 10% greater than a target slot height of the corrugated base paper 104 when forming the slot web 110. For example, to achieve a slot height of 3 mm, a corrugation height h of 3.6 mm may be used, and the corrugator peak 202a of the first roll 102a may be spaced approximately 0.6 mm from the corrugator slot 204b of the second roll 102b. To achieve larger slots, an even larger corrugation height h may be used.

[0089] In some embodiments, the first roller 102a may have a different corrugation height than the second roller 102b. In other embodiments, the first roller 102a may have the same corrugation height as the second roller 102b but may be moved away from close contact by a reduced pressure applied to one or both rollers 102a, 102b.

[0090] In some embodiments, the series of corrugations in one or two corrugated rolls 102a, 102b may have a height h to pitch p ratio of at least 0.5, at least 0.6, or approximately 0.65. These ratios are significantly greater than those of existing equipment, which may have a ratio between 0.3 and 0.4. Therefore, to achieve a similar groove pitch, equipment 100 employs a significantly larger corrugation height.

[0091] It has been determined that, individually and collectively, the aforementioned features can help prevent tearing of the corrugated base paper 104 when it is forced between the corrugations in the corrugating rolls 102a and 102b. Conventional corrugating machines use heat and / or steam to make the corrugated base paper 104 more flexible to prevent tearing. However, in the proposed non-heated environment apparatus 100, it has now been found that tearing can be prevented (or at least minimized) by one or more of the aforementioned features. Specifically, it is believed that not forcing the corrugated base paper 104 to the base of the corrugating grooves 104a, 104b helps reduce the strain in the corrugated base paper 104 that could lead to tearing.

[0092] Furthermore, the described configuration can form a larger, flatter area at the peak of the web 110, which can provide a more effective surface for bonding to the liner material.

[0093] Figure 3 As shown Figure 1 An exploded view of a bonding station 112a, 112b used in the equipment. Each bonding station 112a, 112b includes a rubber roller 300, which includes a series of circumferential flange-like annular protrusions 302 spaced evenly along the axial length of the rubber roller 300. Each end of the rubber roller 300 is configured to lock into drive gears 304a, 304b configured with grooves to engage with the corrugations of the corrugated roller 102b, such that rotation of the corrugated roller 102b causes the rubber roller 300 to rotate at the same circumferential speed. During rotation, the protrusions 302 of the rubber roller 300 are configured to pass through a glue reservoir disposed in a groove 306 before passing through a comb 308 to remove excess glue from the rubber roller 300. When held on the corrugated roller 102b, further rotation of the rubber roller 300 applies the glue present on each of the protrusions 302 to the outer peak of the groove web 110. The series of protrusions 302 form a series of adhesive dots along the length of each peak in the web 110, and the spacing between the protrusions 302 determines the spacing between the adhesive dots. The comb 308 can be adjustable to regulate the amount of adhesive applied to the web 110, and different configurations of the protrusions 302 can be used to change the size and / or spacing of the adhesive dots. Other types of bonding stations 112a, 112b can be provided.

[0094] Understandably, when the padding material is pressed by a pressure roller 116a, 116b into contact with the web 110 of either the first bonding station 112a or the second bonding station 112b, the adhesive dots on the web 110 will promote bonding with the padding materials 114, 122, such as... Figure 1 As shown in the image.

[0095] Figure 4A method 400 for manufacturing corrugated cardboard according to the present invention is illustrated. Method 400 includes a first step 402 of guiding corrugated base paper 104 from a corrugated base paper supply roll 106 to a pair of corrugated rolls 102a, 102b; and a second step 404 of operating the pair of corrugated rolls 102a, 102b to wrinkle the corrugated base paper 104, wherein each corrugated roll 102a, 102b is operated at ambient temperature.

[0096] Figure 5A and Figure 5B A plan view and a side view of a corrugated cardboard 500 manufactured according to the present invention are shown respectively. The corrugated cardboard 500 is cut to form a large rectangular cuboid having a first pad 502 joined to a first side of a slotted web 504 and a second pad 506 joined to a second side of the slotted web 504.

[0097] Advantageously, due to the absence of heat and steam from the manufacturing process, corrugated board 500 is believed to have a less tendency to warp. Furthermore, when corrugated board 500 is manufactured using the described method, it is stronger than prior art corrugated board for the same weight of paper because the absence of heat in the process maintains the paper's strength. Moreover, the flatter peaks of the web 504 ensure a flatter outer surface, and the combination of these flatter peaks with the PVA adhesive achieves a stronger bond than in the prior art.

[0098] Embodiments of the present invention can be used in many different industries to manufacture corrugated cardboard for a variety of applications including (but not limited to) packaging.

[0099] Those skilled in the art will understand that, in the existing description and the accompanying claims, positional terms (such as "above," "along," "side") are used with reference to conceptual illustrations (such as those shown in the accompanying drawings). These terms are for convenience of reference but are not intended to be limiting. Therefore, these terms should be understood to refer to an object in a certain upward direction as shown in the accompanying drawings.

[0100] Although the invention has been described with reference to preferred embodiments as set forth above, it should be understood that these embodiments are illustrative only and the scope of the claims is not limited to these embodiments. In view of the invention, modifications and substitutions will be possible for those skilled in the art, and such modifications and substitutions are contemplated to fall within the scope of the appended claims. Features disclosed or illustrated herein may be incorporated into any embodiment, either alone or in any suitable combination with any other features disclosed or illustrated herein.

Claims

1. A method for manufacturing corrugated cardboard, characterized in that, The method includes: An unheated corrugated base paper is guided from a corrugated base paper supply roll to a pair of corrugated rolls, the pair of corrugated rolls including a first corrugated roll and a second corrugated roll; The pair of corrugated rolls are operated to wrinkle the unheated corrugated base paper; A vacuum system is used to hold the unheated corrugated base paper on the second corrugating roll as it is creased into a grooved web, to achieve a pre-defined portion of rotation; and While the vacuum system holds the grooved web on the second corrugated roll, a first pad is joined to a first side of the grooved web to form a single-sided web. Each corrugated roller operates at ambient temperature; The corrugated cardboard is manufactured without the use of a heat source, and at least achieves and includes corrugations forming the unheated corrugated base paper; The diameter of the first corrugated roll is at least 20% smaller than the diameter of the second corrugated roll, and The vacuum system holds the groove of the web in place to resist the elastic force that causes the unheated corrugated base paper to spring back into a flat configuration, at least from the formation of the web until the first liner is engaged with the web.

2. The method as described in claim 1, characterized in that, The diameter of the first corrugated roll is at least 25%, 30%, 40%, 50%, 60%, or 75% smaller than the diameter of the second corrugated roll.

3. The method as described in claim 1, characterized in that, The steps of operating the pair of corrugated rolls include spacing the pair of corrugated rolls and / or applying pressure such that when the pair of corrugated rolls are engaged together, the corrugating tip of the first corrugated roll is spaced apart from the corrugating groove of the second corrugated roll.

4. The method as described in claim 1, characterized in that, At least one of the pair of corrugated rolls includes a series of corrugations having a height at least 10% greater than a target groove height of the unheated corrugated base paper, and / or At least one of the pair of corrugated rolls comprises a series of corrugations having a height pitch ratio of at least 0.5 or at least 0.

6.

5. The method as described in claim 1, characterized in that, At least one of the unheated corrugated base paper supply rolls or a pressure roll is operated at ambient temperature.

6. The method as described in claim 5, characterized in that, All rollers used in the manufacture of corrugated cardboard operate at ambient temperature.

7. The method as described in claim 1, characterized in that, The ambient temperature is below 60 degrees Celsius.

8. The method as described in claim 1, characterized in that, When passing through the pair of corrugated rolls, the unheated corrugated base paper has a moisture content consistent with environmental conditions.

9. The method as described in claim 1, characterized in that, This includes manufacturing corrugated cardboard without using steam, at least achieving and including the formation of corrugations in the unheated corrugated base paper.

10. The method as described in claim 1, characterized in that, It also includes joining a second liner to a second side of the slotted web to form a double-sided web.

11. The method as described in claim 1, characterized in that, The bonding is achieved using PVA adhesive.

12. A corrugated cardboard manufactured by the method described in any one of claims 1 to 11.

13. An apparatus for manufacturing corrugated cardboard, characterized in that, The device includes: A pair of corrugated rolls configured to wrinkle an unheated corrugated base paper when operating at ambient temperature, the pair of corrugated rolls including a first corrugated roll and a second corrugated roll; A vacuum system configured to hold the unheated corrugated base paper on a second corrugated roll as it is creased into a grooved web, to achieve a predefined portion of rotation. A first joining assembly configured to join a first liner to a first side of the grooved web to form a single-sided web when the grooved web is held on the second corrugated roll by the vacuum system. The equipment is used to manufacture corrugated cardboard without the use of a heat source, at least achieving and including corrugation in the unheated corrugated base paper; The diameter of the first corrugated roll is at least 20% smaller than the diameter of the second corrugated roll, and The vacuum system holds the groove of the web in place to resist the elastic force that causes the unheated corrugated base paper to spring back into a flat configuration, at least from the formation of the web until the first liner is engaged with the web.

14. The device as claimed in claim 13, characterized in that, The first engagement assembly includes a pressure roller, and the pressure roller is configured to operate at ambient temperature.

15. The device as described in claim 13 or 14, characterized in that, The ambient temperature is below 60 degrees Celsius.

16. A corrugated cardboard manufactured using the apparatus as described in any one of claims 13 to 15.

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