Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31F—MECHANICAL WORKING OR DEFORMATION OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31F1/00—Mechanical deformation without removing material, e.g. in combination with laminating
  • B31F1/20—Corrugating; Corrugating combined with laminating to other layers
  • B31F1/24—Making webs in which the channel of each corrugation is transverse to the web feed
  • B31F1/26—Making webs in which the channel of each corrugation is transverse to the web feed by interengaging toothed cylinders cylinder constructions
  • B31F1/28—Making webs in which the channel of each corrugation is transverse to the web feed by interengaging toothed cylinders cylinder constructions combined with uniting the corrugated webs to flat webs ; Making double-faced corrugated cardboard
  • B31F1/2818—Glue application specially adapted therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31F—MECHANICAL WORKING OR DEFORMATION OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31F1/00—Mechanical deformation without removing material, e.g. in combination with laminating
  • B31F1/20—Corrugating; Corrugating combined with laminating to other layers
  • B31F1/24—Making webs in which the channel of each corrugation is transverse to the web feed
  • B31F1/26—Making webs in which the channel of each corrugation is transverse to the web feed by interengaging toothed cylinders cylinder constructions
  • B31F1/28—Making webs in which the channel of each corrugation is transverse to the web feed by interengaging toothed cylinders cylinder constructions combined with uniting the corrugated webs to flat webs ; Making double-faced corrugated cardboard
  • B31F1/2895—Making webs in which the channel of each corrugation is transverse to the web feed by interengaging toothed cylinders cylinder constructions combined with uniting the corrugated webs to flat webs ; Making double-faced corrugated cardboard from corrugated webs having corrugations of particular shape
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B31—MAKING ARTICLES OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER; WORKING PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31F—MECHANICAL WORKING OR DEFORMATION OF PAPER, CARDBOARD OR MATERIAL WORKED IN A MANNER ANALOGOUS TO PAPER
  • B31F1/00—Mechanical deformation without removing material, e.g. in combination with laminating
  • B31F1/20—Corrugating; Corrugating combined with laminating to other layers
  • B31F1/24—Making webs in which the channel of each corrugation is transverse to the web feed
  • B31F1/30—Tools secured to endless chains, e.g. toothed belts; combined with uniting the corrugated web to flat webs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B29/00—Layered products comprising a layer of paper or cardboard
  • B32B29/002—Layered products comprising a layer of paper or cardboard as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B29/005—Layered products comprising a layer of paper or cardboard as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to another layer of paper or cardboard layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B29/00—Layered products comprising a layer of paper or cardboard
  • B32B29/08—Corrugated paper or cardboard
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
  • B32B3/26—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/26—All layers being made of paper or paperboard
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2255/00—Coating on the layer surface
  • B32B2255/12—Coating on the layer surface on paper layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2255/00—Coating on the layer surface
  • B32B2255/26—Polymeric coating

Definitions

• the present invention relates to an improved method and apparatus for forming corrugated board.
• the present invention discloses a method and apparatus for manufacturing single face corrugated board and/or, in some embodiments, double face corrugated board.
• corrugated and fluted and grammatical variants thereof are used interchangeably and refer to a series of alternate ridges (crests) and grooves (troughs).
• Single face corrugated paper board is very well known and is used extensively in industry, especially in packaging where it is used as protective padding and wrapping. It is also used as a basic component in the production of standard cardboard (i.e. double face corrugated board) and many structural objects such as boxes, panels, pallets etc.
• Sheets of single face corrugated paper board can be bonded together to form multilayer corrugated paper boards of various thicknesses and strengths.
• One reason for the wide use of corrugated paper board is its relative light weight, rigidity and strength.
• Single face corrugated paper board is made by bonding a fluted sheet material (generally recycled paper) paper, onto a liner sheet.
• the liner sheet is typically Kraft paper although other materials may be used.
• the fluted sheet is formed by passing a sheet of paper between two corrugating rollers.
• the two rollers are arranged such that there is an inter- meshing of the teeth at the periphery of each roller.
• a sheet of paper is fed between the teeth of the rollers which forces the paper into flutes as the teeth of the rollers intermesh.
• the fluted sheet is held in contact with the teeth on the periphery of one of the corrugating rollers, typically by a vacuum formed within the corrugating cylinder, at least until the liner is added.
• a line of adhesive is applied to the crests of the flutes to bond the liner to the fluted paper.
• a sheet of liner paper is typically pressed onto the crests by a smooth roller so as to bond the liner with the fluted paper thereby forming a single face corrugated (or fluted) board.
• a limiting factor in this process is the requirement to maintain contact between the fluted sheet and the liner for sufficient time for the adhesive to set and a bond to be formed. This time can be several seconds or longer at normal room temperatures and pressures. However, the time has traditionally been reduced by raising the temperature during the bonding process and by applying pressure to the join between the crest and the liner.
• High pressure steam is commonly used to heat the cylinders over which the fluted paper and liner paper move, raising the temperature of the paper.
• Typical operating temperatures for the corrugating rollers can be around 150-20 ⁇ 6 C.
• Pressure can be applied to the joint between the liner and each crest by a pressure roller arranged to press the liner against the adhesive covered crest.
• a pressure roller arranged to press the liner against the adhesive covered crest.
• Some machines are other devices, such as endless belts, to press the liner and fluted sheets together as they move around the corrugating roller. As this extends the period of time pressure is applied, lower pressures can be used so as not to deform the surface of the paper board.
• a problem with both methods of applying pressure is that the applied pressure can spread some of the adhesive away from the contact line between the liner and the crest of the fluted sheet, thus wetting the surrounding paper.
• Adhesive which is spread away from the crest i.e. the contact line
• the superfluous (spread) adhesive remains wet for longer which can lead to problems of the paper board deforming as it dries at an uneven rate, and being difficult to cut or process further until it is fully dry.
• a common solution is to apply additional heating to dry out the paper and superfluous (spread) adhesive. However, this adds to the cost of production and may limit the speed of the process.
• the spread adhesive can also get transferred to the surface of the device applying the pressure (e.g. the roller or belt) requiring that surface to be continually cleaned. Furthermore, some of the spread adhesive can be transferred to the outer surface of the liner, which can cause problems during storage when rolled, as neighbouring sheets can stick together making the product unusable. In addition, the excess spread adhesive can mark the surface, adversely affecting the appearance and the value of the corrugated board.
• a further disadvantage with conventional machines is that typically both the feed rollers (used to feed the paper onto the corrugating rollers whether to be fluted or used as a liner) and the corrugating rollers, are heated in order to dry out the paper prior to addition of 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 pre-heat the paper can require a significant amount of energy. All of the above factors can add significantly to the cost of single face corrugated board made by conventional processes and machines.
• a further problem with conventional corrugators is that: the application of heat to the paper ;combined with the continuous adjusted braking force applied to the paper coming off the reel stand to keep its path straight; all result in corrugated board being produced which curls at the corners and is thus not a dead flat sheet (as observed with the naked eye) which would be a higher value end product with no wastage.
• Continuous braking is required because the paper as it is wound onto the reel at the pulp and paper factory, is subjected to left and right tensional forces, which cause the paper to deviate from a straight path when it is unwound off the reel.
• continuous process' refers to a process in which the corrugated sheet material can be bonded to the planar sheet material immediately following the formation of the corrugated sheet material by the intermeshing of the large and smaller corrugating rollers imparting flutes to a previously planar sheet material so as to enable the production of single face board by a single continuous (i.e. uninterrupted) process.
• a method of bonding a substantially planar sheet material to a corrugated sheet material both of which are porous using a continuous process the method characterised by the steps of: a) applying a controlled amount of adhesive to the apex contact portion of the corrugated sheet material; and b) holding the respective planar and corrugated sheets together at a specified pressure and for a specified pressing period so that a bond is formed between them.
• steps a) and b) are undertaken at an ambient temperature.
• the adhesive is applied and sets at an ambient temperature.
• the adhesive may be heated prior to application (depending on the nature of the adhesive used) but in all such embodiments the adhesive selected must be such that it will set at an ambient temperature.
• 'apex contact portion' refers to the top part of the crest of a flute on a corrugated sheet of material which becomes pressed into abutment with the planar sheet at step b) of the process.
• the apex contact portion includes the apex of the crests and that region on either side thereof which will become pressed into direct contact with, and then bonded, by the spread of adhesive, to the planar (liner) sheet.
• the inventor has found that significant problems occur if the adhesive extends beyond the apex contact portion onto the sides of the
• Such problems include: increased bond time as the porosity of the liner cannot absorb the moisture in the adhesive outside the apex contact portion;
• the specified pressure is as high as possible without compromising the integrity of the paper.
• the specified pressure is less than the tear strength of the porous sheet materials selected. The inventor has found that the higher the specified pressure the quicker the bond time.
• the porous sheet material may generally be paper but can include other sheet materials with similar characteristics making it suitable for forming corrugated board.
• a key characteristic of the sheet material is that the porosity is sufficient to absorb substantially most of the moisture in the adhesive at the specified pressure.
• RP DHT/BT wherein RP is the rate of production in metres/minute; DHT is the distance in metres for which the two respective sheets are held together; and BT is the bond time of the adhesive in minutes.
• RP DHT/BT to determine the diameter of the large corrugating roller and percentage of the circumference of the large corrugating roller about which an endless belt assembly needs to apply pressure so as to achieve the desired rate of production; wherein RP is the rate of production in metres/minute; DHT is the distance in metres for which the two respective sheets are held together; and BT is the bond time of the adhesive in minutes.
• an apparatus which bonds substantially planar porous sheet material to corrugated porous sheet material, to produce a single face corrugated porous sheet material as part of a continuous process which utilises a large corrugating roller and a smaller corrugator roller and glue applicator assembly together with an endless tensioned belt , wherein the rate of production of the apparatus has been determined by the formula:
• RP DHT/BT wherein RP is the rate of production in metres/minute; DHT is the distance in metres the two respective sheets are held together; and BT is the bond time of the adhesive in minutes.
• BT DHT/RP wherein RP is the rate of production in metres/minute and DHT is the distance in metres the two respective sheets are held together.
• the maximum values of X increase with increasing diameter of the larger corrugating roller as outlined further below.
• 'large roller', 'large diameter corrugating roller' or 'large diameter intermeshing corrugating roller' or the like as used herein are interchangeable and refer to a corrugating roller that has a diameter which is at least twice the diameter of the 'smaller diameter roller', 'smaller diameter corrugating roller' or 'smaller diameter intermeshing corrugating roller'.
• an apparatus which bonds a substantially planar porous sheet material to a corrugated porous sheet material, to produce a single face corrugated porous sheet material via a continuous process
• the apparatus includes a large diameter corrugating roller intermeshing with a smaller diameter corrugating roller, and an endless tensioned belt assembly arranged to apply pressure over the circumferential surface of the large corrugating roller to facilitate lamination of the planar and corrugated sheets wherein the circumference of the large diameter corrugating roller about which the endless belt can apply tension is governed by the formula:
• C (RP.BT)/X wherein C is the circumference of the roller (i.e. ⁇ 2r) ; RP is the rate of production in metres/minute and BT is the bond time in minutes; and X is maximum
• an apparatus which bonds a substantially planar porous sheet material to a corrugated porous sheet material to form single face corrugated porous sheet material via a continuous process
• the apparatus includes a large diameter corrugating .
• roller intermeshing with a smaller diameter corrugating roller, and a endless tensioned belt assembly which includes a tensioned belt arranged to apply pressure over the circumference of the large corrugating roller to facilitate lamination of the planar and corrugated sheets wherein the percentage of the circumference of the large corrugating roller which does not have the tensioned belt applying pressure thereto is limited solely by the minimum relative space required for the smaller corrugating roller and glue applicator assembly.
• RP DHT/BT wherein RP is the rate of production in metres/minute; DHT is the distance in metres the two respective sheets are held together; and BT is the bond time in minutes.
• the belt assembly is configured so the belt can apply pressure over 70% - 93% of the circumference of the large corrugating roller.
• the inventor has found the diameter of the large corrugating roller which can range substantially anywhere from 0.4m - 2.0m determines the maximum percentage that the endless belt is able to extend around the circumference of the largest corrugating roller, whilst leaving room for:
• the maximum percentage the endless belt can extend around the periphery Of the large roller is substantially 70%
• the maximum percentage the endless belt can extend around the large roller is substantially 93%.
• the inventor has found the average circumferential distance of the large roller required to provide room for the glue roller and smaller corrugating roller embodiment mentioned above may be substantially in the order of 0.45m - 0.5m.
• the large corrugating roller may have a diameter of substantially 0.62m and the endless belt applies a pressure around 76% of the circumference of the large roller.
• the large corrugating roller may have a diameter of 2m and the endless belt applies a pressure around 93% about the circumference thereof.
• a method of operating a large diameter corrugating roller intermeshing with a smaller diameter corrugating roller and an endless tensioned belt comprising a pressing step in which the tensioned belt is arranged to apply pressure over a portion of the circumferential surface of the large corrugating roller to form an adhesive bond between a substantially planar porous sheet material and a corrugated porous sheet material comprising the further step of using the percentage of belt span about the circumference of a larger corrugating roller to determine the rate of production.
• a method of using a tensioned belt and a large diameter corrugating roller intermeshing with a smaller diameter corrugating roller and glue applicator assembly to produce single face corrugated board from a porous planar sheet material and planar corrugated sheet material comprising the step of applying an adhesive to the corrugated sheet material, at an ambient temperature, and then holding the respective planar and corrugated sheets together via the tensioned belt, for a specified period of time.
• RP XCrr2 r).BT wherein RP is the rate of production in metres/minute and BT is the bond time in minutes and X is the percentage of the circumference of the large corrugating roller about which pressure is applied by the endless tensioned belt.
• RP ⁇ ( ⁇ 2 r).BT wherein RP is the rate of production in metres/minute, BT is the bond time in minutes, and X is the percentage of the circumference of the large corrugating roller about which pressure can be applied by the endless tensioned belt.
• RP X0rr2 r).BT wherein RP is the rate of production in metres/minute, BT is the bond time in minutes, and X is the percentage of the circumference of the large corrugating roller about which pressure is applied by the endless tensioned belt.
• RP is substantially in the range of at least 25m/min - 200m/min.
• the sheet material is Kraft paper.
• Kraft paper is commonly used in the formation of single face corrugated board.
• other porous sheet materials may be used with the present invention and therefore reference throughout this specification to sheet material being Kraft paper should not be seen as limiting.
• planar sheet material known as a liner may also be made from Kraft paper.
• substantially planar should be understood to refer to a sheet or web having a substantially flat surface, in which lies with a single plane (at least when viewed with the naked eye).
• corrugated In contrast reference to the term “corrugated” should be understood to refer to a sheet or web in which the surface is configured into a series of alternating crests and troughs (i.e. corrugations).
• the corrugations in a corrugated sheet used to form a single face corrugated paper board are commonly referred to as flutes.
• Flutes are typically formed by passing a sheet of Kraft paper through a pair of corrugating rollers set in relation to one another so that the teeth of the corrugating rollers intermesh-on either side of the Kraft paper.
• the shape of the resulting flute is dependent on the shape and size of the teeth on the corrugating rolls.
• a flute can be triangular, sinusoidal, trapezoidal, saw-tooth, rhombic, square or any other suitable repeating undulating shape.
• the size of the flute is determined by the equi-size of the teeth and may be varied depending on the end application for the single face corrugated board.
• the corrugated sheet material has flutes with a substantially triangular sectional profile.
• An advantage of having a substantially triangular sectional profile flutes is that this profile is relatively simple to form using conventionally formed teeth on the corrugating rollers.
• triangular shaped flutes may have added strength in comparison to . some of the other shapes, particular against compression along the length of a flute.
• the adhesive used to bond a liner to the apex contact portions of a fluted sheet, where the liner and the fluted sheet are formed from Kraft paper, is typically a water-based glue.
• the adhesive may also be a non-water based glue provided it is liquid-like during application to the apex contact portion and can be absorbed by the porous sheet material in accordance with the present invention.
• controlled amount of adhesive refers to a measure of adhesive which is applied to the apex contact portion such that it does not extend beyond the apex contact portion prior to or during bonding step b).
• a "controlled amount of adhesive” can therefore include a bead of glue, coating of glue, or droplets of glue, which is/are placed along, or on, the apex contact portion of each crest of a fluted sheet.
• the controlled amounts of adhesive can vary in form depending on the mode of application.
• the distinct amounts may be in the form of a thin line, smear, a network of fine interconnected lines, interrupted line(s) or dash(es).
• the key for achieving a bond between the respective sheets is for the adhesive to first wet and penetrate the corrugated sheet and then wet and penetrate the second sheet (liner).
• a controlled amount By having a controlled amount, less adhesive is applied to the fluted sheet than is the case with conventional methods. Further, a controlled amount also ensures that the adhesive does not extend beyond the apex contact portion and especially so during step b). Thus a controlled amount allows for some spread of adhesive to occur on to dry areas of the respective sheets once pressure has been applied to the liner and the fluted sheet.
• the adhesive is applied across the apex contact portion in spaced apart droplets in a manner substantially as is disclosed in the applicant's earlier PCT Application WO 2009/1 5642 where the droplets are applied to the crest.
• the droplets will be small round, or pear shaped portions of adhesive that adhere to a surface, but this should not be seen as limiting.
• the preferred size of the droplet may depend on a number of factors, including the nature of the fluted paper and liner and the type of adhesive used. However, in all cases the droplet size should be small enough that the droplet substantially retains its form and does not collapse under its own weight. This is important as the relatively high volume to surface area (in comparison say to a strip or line of adhesive) reduces the rate of evaporation of moisture from the droplet, thus extending the time available for the droplet of adhesive to wet and penetrate the crest of the fluted paper and the liner prior to the adhesive drying out.
• a preferred droplet size is in the order of 0.5mm 3 .
• the preferred gap between droplets is calculated by ascertaining the desired adhesive thickness when spread and placing the droplets apart so when the spread droplets reach that thickness they just meet each other.
• the adhesive is applied to the apex contact portion in the form of a thin continuous bead (i.e. line of adhesive).
• the applicant has found that the present method can be used to produce single face corrugated board without the application of heat to effect a bond between the fluted sheet material and the liner sheet material.
• ambient temperature refers to the temperature of the room/building in which the apparatus can operate and perform the method of the present invention.
• the ambient temperature is a temperature between substantially 5°C - 60°C.
• an ambient temperature may be a temperature of between substantially 10 °C - 25 °C.
• the liner is pressed against the fluted sheet at a specified pressure for a specified time so a bond can form. This may be achieved by a variety of means.
• planar (liner) sheet is pressed against the corrugated (fluted) sheet by a tensioned endless belt assembly
• 'specified pressure' refers to the pressure applied by the belt to the large surface of the corrugating roller which is set to be at, or just below, the maximum pressure that can be applied without deforming the paper (liner and fluted papers). Excessive pressure can lead to creasing and/or tearing of the paper. The maximum pressure will vary depending on the material used for the liner and fluted paper.
• the sheet materials are held together for a period not less than two seconds.
• the liner and fluted sheet need to be pressed together for a period (pressing time) longer than about two seconds at room temperature to ensure the liner and fluted board form a good bond.
• the pressing time is less than around two seconds, or if the. pressure between the sheets is too little, a single face corrugated board will not be completely or adequately formed. In such cases, the tension in the corrugated sheet is sufficient to break the bond, resulting in the liner coming away from the fluted sheet.
• a pressing time of around two or three seconds is significantly slower than that achieved by some prior art machines which use a combination of high temperature and high pressure.
• an advantage of the present invention is that it may produce quantities of single face corrugated board at an acceptable rate at room temperature. This provides the advantage of a process and apparatus which may produce single face corrugated board at a reduced cost and in a safe and environmental friendly manner.
• the inventor considers the combination of: using a controlled amount of adhesive; - applying the adhesive to the apex contact of the corrugated sheet;
• the adhesive is a water-based glue suitable for bonding porous materials such as paper.
• the adhesive may be a dispersion containing vinyl acetate copolymer.
• a water-based adhesive containing vinyl acetate copolymer in dispersion may be preferred as, under normal use, it is a non-hazardous substance, and therefore can be used safely provided normal ventilation is provided.
• Vinyl acetate copolymer dispersions can be relatively quick setting at room temperature and do not require a high activation temperature - unlike starch based glues. They have a low viscosity, good adhesion and a long open time. A relatively low viscosity is required to allow the adhesive to flow readily, (e.g., when being transferred from an applicator to the fluted sheet) while a good adhesion provides the ability to adhere quickly to a surface.
• the open time is a measure of the time, under normal temperature and pressure, that the adhesive can have an exposed surface before it loses its ability to wet the opposing surface and penetrate into the opposing surface fibres. This wetting and penetration is required to form an effective bond between the fluted paper and the liner.
• An adhesive having a relatively long open time is preferred as the adhesive may be open to the atmosphere for some time prior to application to the flutes.
• the adhesive is AdhesinTM Z9129W, a vinyl acetate copolymer supplied by Henkel New Zealand Limited.
• AdhesinTM Z9129W has the required viscosity, and long open time required for use with the present invention.
• AdhesinTM Z9129W has a viscosity in the range 2100-2200 m.Pa.S and an open time of between 0.5 to 1 minute.
• other adhesives having similar properties may also be used.
• an adhesive such as Adhesin( Z9129W) in droplet form to the crest of a fluted sheet, and pressing a liner against the crest for around 3 seconds to form a bond between the fluted sheet and liner, provides a number of significant advantages over the prior art.
• the method may be used to produce single face corrugated paper board at ambient temperature. As a result there is no need for heating of the corrugating rolls or drying out of the single face corrugated board. This may translate into a significant reduction in energy use and hence lower the production cost of the paper board.
• a glue applicator for applying a controlled amount of adhesive includes a roller wherein the outer surface of the roller has a contoured surface.
• AdhesinTM Z9040 which takes around 2 seconds to form bond between the fluted sheet and the liner.
• the contoured surface can come in a number of forms and in one embodiment may be a dimpled or an irregular surface. In some embodiments the contoured surface may be in the form of a U-shaped groove.
• the roller may also in some further embodiments be similar to an anilox roller.
• the contoured surface is in the form of fine corrugations reminiscent of a square wave.
• the contoured surface may be a corrugated surface. It should be understood that a corrugated surface refers to a surface formed into a series of crests and troughs.
• the crests (and troughs) are substantially parallel and extend around the circumference of the roller.
• the crests form a spiral.
• the crests may form concentric circles.
• the crests and troughs may be formed by cutting (or otherwise shaping) a 'V or square shaped groove in the surface of the glue roller.
• the actual shape of the groove is not critical, but a 'V shaped groove is preferred as it is relatively easily cut into a smooth cylindrical surface.
• adhesive may be supplied to the glue roller by a smooth surface pick-up roller.
• spray nozzles may be used or an air blade that passes through a trough.
• the pick-up roller is preferably mounted adjacent to an adhesive bath such that the outer surface is coated with adhesive as the pick-up roller rotates.
• the glue roller is mounted with respect to the pick-up roller such that the crests of the glue roller make firm contact with the surface of the pick-up roller. In this way adhesive is transferred from the surface of the pick-up roller into the grooves in the surface of the glue roller, with little or no adhesive being applied to the crests of the applicator roller.
• the gap between the pick up roller and the glue roller determines the amount of glue being applied.
• the mounting of the glue roller is also such that the crests of the applicator roller make firm contact with the crests of the fluted sheet on the corrugating roller.
• the glue roller rotates it picks up adhesive in the grooves on its surface as it contacts the pick-up roller, and then deposits the adhesive as droplets onto the crests of the fluted sheet.
• the amount of adhesive for each droplet may be determined by the size (width and depth) of each groove, while the separation of the droplets may be determined by the separation of adjacent grooves.
• the groove should be sufficiently shallow to avoid too much glue being deposited onto the corrugated sheet material.
• the groove should be dimensioned so that glue is only deposited onto the apex contact portion.
• the depth of the groove is 0.5 mm and the width of the groove is in the order of 1 mm.
• the crest may take the form of a sharp edge.
• the 'V'-shaped grooves on the roller are arranged such that each groove abuts the adjacent grooves to form a sharp edge so that a section through a series of grooves forms a continuous zigzag pattern.
• This arrangement may provide the minimum separation between adjacent droplets (for a given width of each groove).
• the crests may have a flat section, in which case the separation of the droplets may be correspondingly larger.
• the glue roller is rotatably mounted such that the outer surface (crests) of the applicator press against the crests of the fluted paper held on the second corrugating roller.
• a method of " bonding a substantially planar sheet material to a corrugated sheet material both of which are porous using a continuous process the method characterised by the steps of: a) applying adhesive to the corrugated sheet material with a glue application (GA) roller which has lateral left to right grooves about the GA roller's circumference which engage with teeth on the corrugating roller wherein said grooves in the GA roller hold a set amount of glue therein b) holding the respective planar and corrugated sheets together at a specified pressure and for a specified time so a bond is formed there between.
• a glue application (GA) roller which has lateral left to right grooves about the GA roller's circumference which engage with teeth on the corrugating roller wherein said grooves in the GA roller hold a set amount of glue therein
• the dimensions of the grooves on the GA roller enable a line of adhesive to be held therein; the teeth (or a portion thereof) on the corrugating roller and apex contact portion of the corrugated sheet to be received therein; such that a line of adhesive can be applied to the apex contact portion of the corrugated sheet.
• an apparatus for making single face corrugated board by bonding a corrugated sheet material having one or more crests onto a substantially planar sheet, both of which are porous including an applicator configured to apply adhesive to each crest of the corrugated sheet material, and a pressing mechanism for pressing the planar sheet against the crest of the corrugated material characterised in that the applicator is configured to apply a controlled amount of adhesive to apex contact portions on each crest of the corrugated sheet material and wherein the pressing mechanism is configured to press the planar sheet material against the corrugated sheet material at a specified pressure for a specified time so a bond is formed there between.
• an apparatus for making single face corrugated board according to the present invention has many features in common with some prior art machines.
• a fluted sheet is formed by passing a sheet material between the intermeshed teeth of first and second corrugating rollers.
• the fluted sheet is held against the second corrugating roller, which has a larger diameter than the first corrugating roller, by a vacuum created inside the second corrugating roller.
• the fluted paper passes an applicator where adhesive is applied to the apex contact portion of the fluted sheet.
• the applicator includes a roller having a corrugated surface substantially as described above.
• the corrugated surface of the glue roller and grooved surface of the GA roller are respectively configured to apply droplets or a line of adhesive across an apex contact portion on a crest of a fluted sheet. This is in contrast to conventional machines in which the applicator typically has a knurled surface so as to spread a relatively broad strip or line of adhesive across the crest of the flute. Conventional machines therefore tend to apply more adhesive than is required and the adhesive is thus not contained within the apex contact region.
• the pressing mechanism is a tensioned endless belt assembly.
• An endless belt may be configured to move around a plurality of rollers, the rollers being arranged such that the belt is held in contact with the liner as the liner and fluted sheet move around the periphery of the second corrugating roller.
• This arrangement may be achieved by placing two end guide rollers spaced apart around the periphery of the second corrugating roller, the spacing defining the distance over which the belt contacts the liner.
• the two end guides may be mounted so as to provide pressure (via the belt) onto the liner as it initially contacts the fluted sheet, and again just before the single face fluted sheet is removed from the second corrugating roll.
• the belt may be tensioned by adjustment of one or more of the remaining rollers so that the belt applies pressure to the liner to press it against the fluted sheet.
• a standard rubber belt may be used, rather than the more expensive materials used with heated rollers. Use of a standard rubber belt may result in less damage to the surface of the liner, and hence a superior product.
• the endless belt may be made of plastics or synthetic material.
• the endless belt when applied at ambient temperature, is that the endless belt may be formed using heat sensitive materials such as plastics, synthetics and some rubbers that would not be suitable in conventional, heated processes.
• the endless belt is configured to press the sheet materials together for at least 2 seconds.
• the endless belt is configured to press the sheet materials together for a time between about 2 seconds and about 4 seconds as aforesaid.
• the present invention allows the efficient production of single face corrugated board without requiring additional heat to be applied to the process.
• This feature is achieved by the combination of applying a controlled amount of adhesive to the apex contact portion followed by pressing the liner against the ⁇ fluted sheet at a specified pressure for a specified pressing time until a bond is formed.
• an apparatus which bonds substantially planar porous sheet material to a corrugated sheet material via a continuous process
• the apparatus includes large corrugating roller which intermeshes with a smaller corrugating roller wherein the diameter of the smaller roller is at least substantially between 0.16m-0.2m diameter and the large corrugating roller has a diameter of at least substantially between 0.4m-2.0m.
• the machine may be cheaper to make and be supported by a lighter frame, again saving on material cost.
• the present method may result in significantly less consumption of adhesive.
• an apparatus according to the present invention may be of a size and cost that makes it suitable for on-site production of single face corrugated board.
• Conventional heated machines are typically large, energy intensive and expensive to construct and operate. As a consequence such machines are commonly operated in centralised locations, with the single face corrugated board, or products made from it, transported to consumers.
• the size of the machine according to the present invention is scalable, mainly because no heating apparatus is required.
• an apparatus according to the present invention may be of a size suitable for installation and operation on the site of the consumer, for example to make packaging on site. This may provide savings to the consumer, as supply would be controlled by the consumer, and there would be no transport and handling costs from off-site production.
• RP DHT/BT in the construction of a single face paperboard manufacturing facility; wherein RP is the rate of production in metres/minute; DHT is the distance in metres for which the two respective sheets are held together; and BT is the bond time of the adhesive in minutes.
• adhesive may be a dispersion containing vinyl acetate copolymer.
• an apparatus for manufacturing corrugated sheet of material from porous planar sheet material via an automated process wherein the apparatus includes: a corrugating roller; an endless fluted conveyor belt assembly having an endless fluted conveyor surface including a plurality of adjacent flutes wherein the flutes are configured to correspond to the teeth on the corrugating roller.
• an apparatus for manufacturing a single face corrugated sheet of porous material via an automated process wherein the apparatus includes: a . corrugating roller; an endless fluted conveyor belt assembly having an endless fluted conveyor surface including a plurality of adjacent flutes wherein the flutes are configured to correspond to the teeth on the corrugating roller.; a pressure mechanism configured to hold freshly corrugated sheet material to the fluted conveyor surface whilst adhesive is applied by a glue applicator; an endless tensioned belt assembly which holds planar sheet material and the corrugated sheet material together so a bond is formed there between.
• the endless fluted conveyor surface may come in a variety of different forms without departing from the scope of the present invention.
• the strip may be in the form of a slat. In some further preferred embodiments the strip may be in the form of a bar which has a rectangular transverse cross section.
• the bars or slats may each have connection portions at opposed ends thereof (with respect to the intended direction of travel along the conveyor) to enable pivotal attachment to adjacent strips to form and endless fluted conveyor surface.
• the endless fluted conveyor surface may be in the form of an endless belt.
• the belt may include a flexible base layer and a fluted rigid outer layer, wherein the outer layer is configured to move around rollers forming part of the conveyor belt assembly.
• the endless fluted conveyor surface may be made from a variety of different materials without departing from the scope of the present invention.
• the bars/slats are made from steel.
• the bars/slats may be made from plastics, wood, or composite materials.
• the bars/slats may be made of Perspex.
• the teeth on the corrugator and flutes on the endless conveyor may have a number of different profiles without departing from the scope of the present invention provided the shape of the flutes are capable of intermeshing with the teeth on a corrugating roller.
• the teeth on the roller may have any one of: A, B, C, D, E, F or G shaped profiles.
• the teeth/flutes may be formed via V-Shaped grooves.
• the endless conveyor surface may include a number of apertures passing from the top to the bottom surface and positioned substantially along the length of the endless conveyor surface.
• the purpose of the apertures is to allow for the application of a vacuum to the corrugated sheet material to hold it against the flutes of the endless conveyor surface.
• the apertures may be in the form of slots which form a staggered pattern along the length of the endless conveyor surface.
• the pressure mechanism may come in a variety of forms without departing from the scope of the present invention.
• the pressure mechanism may be in the form of two or more elongate fingers which pass through radial grooves in the corrugating roller and glue roller.
• the corrugating roller and glue roller may be constructed in sections with a gap between sections in which the fingers may be located. The fingers are attached to a biasing device which allows the fingers to hold the corrugated sheet material against the slatted conveyor.
• the pressure mechanism may be in the form of a vacuum box located within the slatted conveyor and configured to apply a vacuum to the slats as they pass the vacuum box.
• the endless belt assembly may be configured to move around a plurality of rollers as is well known in the art.
• the rollers being arranged such that the belt is held in contact with the liner as the liner and fluted sheet move around the periphery of the endless fluted conveyor belt assembly which effectively functions as a second corrugating roller.
• the endless fluted conveyor belt assembly which is formed from a plurality of adjacent slats may be configured in a number of different ways without departing from the scope of the present invention.
• the slatted conveyor belt assembly may include one or more flexible belts to which the slats are attached.
• the belts move around rollers and are driven by a drive mechanism as is known in the art.
• the glue applicator may take a number of different forms.
• the glue applicator may be a grooved glue roller which intermeshes (engages) with the teeth on the slats.
• the glue roller receiving glue from a glue pick up roller and associated glue tray.
• glue applicator may also be configured in other ways substantially as described above.
• an apparatus for manufacturing double face corrugated board via a continuous in-line automated process wherein the apparatus includes: i) a single face corrugator module comprising:
• an endless fluted conveyor belt assembly having an endless fluted conveyor surface including a plurality of adjacent flutes wherein the flutes are configured to correspond to the teeth on the corrugating roller.
• the module is configured so that sheet material passing between the respective intermeshing teeth on the corrugating roller and endless fluted conveyor belt assembly becomes corrugated and is subjected to a first pressure mechanism before contacting a glue applicator and coming into contact with planar sheet material and a second pressure mechanism in the form of an endless tensioned belt assembly which holds the respective planar and corrugated sheets together so a bond is formed there between.
• a laminator module comprising:
• BT DHT/RP wherein RP is the rate of production in metres/minute; DHT is the distance in metres the two respective sheets are held together; and BT is the bond time in minutes of the adhesive used and this determines the pressing period.
• single face board which has been produced by a method substantially as described above.
• double face board which has been produced by a method substantially as described above.
• double face board which has been produced from single face board substantially as described above.
• single face board which has been produced from a pre-printed planar sheet being directly bonded to a corrugated sheet material at an ambient temperature.
• pre-printed double face board which has been produced from a pre-printed planar sheet being directly bonded to a corrugated sheet of material forming part of a single face board which was produced at an ambient temperature.
• the pre-printed planar sheet is applied to the single face board immediately after it has been formed as part of the automated continuous in-line process.
• double face board which has been produced from two pre-printed planar sheets being directly bonded to upper and lower surfaces of a corrugated sheet material at an ambient temperature. It will be understood that the pre-printed planar sheets are bonded to the corrugated sheet material so that the printed surface(s) become exposed surface(s) of the single face/double face board.
• DHT equates to ⁇ ( ⁇ 2r).
• the maximum value of X for large corrugator roller constitutes a rate limiting step - as the diameter of the large corrugator roller cannot be increased much beyond 2 meters as this would make the roller incredibly heavy.
• the length of a linear corrugator can be increased easily and almost without limit should this be desired.
• the advantages provided by preferred embodiments of the present invention in relation to both linear and non-linear corrugators also include: the ability to apply pre-printed paper directly to the corrugated board as part of an in-line continuous automated process; the ability to produce single or double face corrugated board which is dead flat to the naked eye and not prone to curling due to the fact it has been produced with the absence of heat and with a passive braking system for paper coming off the reel.
• Figures 1A and I B show the apex contact portion on a schematic side elevation of a fluted sheet both pre- and post- bonding to the liner;
• Figure 2 shows a schematic perspective view_of part of a single facer apparatus according to one preferred embodiment of the present invention.
• Figure 3 shows a perspective view of the single facer apparatus shown in
• Figure 4 Shows a schematic perspective view of part of a single facer apparatus according to a further preferred embodiment of the present invention.
• Figure 5 shows a schematic perspective view of a linear corrugators for producing single face corrugated board in accordance with a preferred embodiment of a further aspect of the present invention.
• Figure 6 shows a schematic perspective view of an apparatus for
• Figure 7 shows a plan view of a cylindrical bar detailed in the
• Figure 8 shows a plan view of an alignment bar detailed in the
• Figure 9 shows a plan view of a convex roller detailed in the endless tensioned belt assembly of the embodiment shown in Figure 2.
• Figure 10 shows a schematic perspective view of an apparatus for
• Figure 11 shows a portion of an endless conveyor surface in the form of a conveyor belt made from a plurality of strips in the form of fluted bars.
• Figure 12 shows side view of a fluted bar forming part of the conveyor belt of Figure 11.
• Figure 13 shows transverse cross sectional view of the flute bar in Figure 12.
• Figure 14 shows a perspective view of the fluted bar in Figure 12.
• FIGs 1 A and 1 B there is shown a schematic view of a corrugated (fluted) sheet of paper (100) illustrating the apex contact portion (101 ).
• the apex contact portion includes the apex (102) of the crests (103) and a region either side which will become abutted by the spread of adhesive (104) to the liner sheet (105).
• FIGS 2 and 3 show a portion of an apparatus for forming single face corrugated board known as a single facer generally indicated by arrow (200).
• the single facer (200) has a first smaller corrugating roller (201 ) and a second large corrugating roller (202). It will be appreciated for clarity the rollers(201 ,202) pictured in this drawing are not shown in full but would be built up by a assembling a series of the roller components and placing these side by side on an axle (not shown) until the desired width of roller is achieved.
• porous sheet material in the form of Kraft paper (250) is fed to the corrugating rollers (201) and (202). After passing the rollers (201 ,202) the Kraft paper (250) becomes corrugated (fluted) sheet material (251 ).
• the second roller (202) has teeth (203) which engage with lateral grooves (204) on the surface of a glue applicator (GA) roller (205).
• the surface of the glue applicator roller (205) picks up adhesive in the form of AdhesinTM Z9040 from a glue bath (not shown) and excess glue is removed from the surface via a glue scraper (206) such that adhesive only remains in grooves (204).
• newly corrugated sheet material (251 ) which is held via a vacuum to second roller (202) passes between the second roller (202) and glue roller (205) such that the apex contact portion (not shown) of the corrugated sheet material is received within the grooves (204) along with teeth (203) to achieve the transfer of adhesive to the apex contact portion.
• planar (liner) sheet material (260) in the form of Kraft paper is fed in between an endless tensioned belt assembly (270) and the second corrugating - roller (202) and bought into contact with the apex contact portions of the corrugated sheet material (251).
• the endless tensioned belt assembly has an endless belt (271) which applies a specified pressure to the planar sheet (260) to hold against the corrugated sheet (251).
• the endless belt (271) applies a specified pressure to 76% of the circumference of large roller (20) as indicated by arrow X.
• the sheet material (260) can in some embodiments be pre-printed with high quality graphic images and/or text.
• the endless tensioned belt assembly has a series of rollers (290 - 294) tension applied by radially adjusting a tension roller (292) with respect to the axis of the second large corrugating roller (202).
• tension in the belt (271) is first adjusted to the point where damage normally in the form of, creasing or tearing, of the liner and/or fluted paper occurs.
• the tension is then reduced by gradually adjusting the tensioning roller (292) back to a point where damage no longer occurs to the liner/fluted paper (i.e. the tensioning roller is adjusted back to the specified pressure).
• BT DHT/RP wherein RP is the rate of production in metres/minute; DHT is the distance in metres the two respective sheets are held together; and BT is the bond time in minutes.
• RP the rate of production in metres/minute
• DHT the distance in metres the two respective sheets are held together
• BT the bond time in minutes.
• the circumference of the second corrugating roller (202) is governed by the formula:
• C (RP.BT)/X wherein C is the circumference of the roller (i.e. ⁇ 2r) ; RP is the rate of production in metres/minute; and BT is the bond time in minutes and X is the percentage of the circumference about which pressure is applied by the endless tensioned belt.
• the circumference of the second roller is 44x0.0333 which is 1 .4666 divided by 76% which equals 1 .93 m. This equates to a diameter of 0.62m. In other words the DHT in this example is equal to 2nr multiplied by 0.76%.
• the Kraft paper used may 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 lead from a vacuum pump not shown to the surface of the roller (not shown) so that a partial vacuum can be created inside the corrugating roller (202) via the vacuum pump. This partial vacuum inside the second corrugating roller (202) holds the fluted sheet (260) in place against the teeth (203) of the second corrugating roller (203).
• the apparatus (200) has a first and second alignment system generally indicated by 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 off the reel (not shown).
• the alignment system keeps the path of the paper (250) straight as it comes off the reel and enters the apparatus (200).
• the cylindrical bars (510-512) do not rotate but instead impart a frictional force which allows the bars to keep the path of the paper straight and prevent any left and right movement of the paper as it comes off the reel.
• the cylindrical bars (510-512) also have flanged ends (513) (refer Figure 7) which prevent the paper from tracking off the cylindrical bars and becoming non-aligned with the apparatus (200).
• the second alignment system (502) has a first alignment bar (520) which has flared ends (525) (refer Figure 8) which taper out from a cylindrical centre section which is the width of the paper (260) coming off a reel (not shown).
• the flared ends extend about 50mm 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 Figure 7).
• the paper (260) then passes to a second alignment bar (522) which has flared ends refer (Figure 8). Again the bars ((520,521 and 522) are stationary as with the first alignment system (500).
• the paper (260) passes over roller (290) of the endless tensioned belt assembly (270).
• the roller (290) has a convex outer surface (refer Figure 9). The inventor has found that the convex outer surface on this roller minimises the risk of the paper gathering in the centre and creasing prior to entering the apparatus (200). This gathering occurring as a result of the paper being redirected towards the centre via the second alignment bar (522) whose flared ends prevent any left or right deviation of the paper over the bar (522).
• the relative position of the bars with respect to each other and the respective reels in the first and second alignment systems (500) and (502) may be adjustable so the right pressure can be applied to the paper to keep it aligned with the apparatus (200).
• the endless tensioned belt assembly (270) via the belt (271) applies pressure to the liner (260) and the fluted paper (251) (formerly Kraft paper 250), as they respectively travel around 76% of the circumference of the roller (203) as indicated by arrow X: until single face corrugated board (280) is created and exits the apparatus (200).
• the apparatus also includes a double facer (not shown) but which is well known in the art.
• Figure 4 shows an apparatus which is similar to that shown in Figures 2 and 3 and thus like reference numerals 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 corrugating roller (202) is 1m whereas in Figures 2 and 3 the large corrugating roller (202) has a diameter of 2m and the endless belt (271) applies a pressure about 93% of the circumference of the large roller (202) as indicated by arrow X.
• FIG. 5 shows an apparatus for manufacturing single face corrugated sheet material in the form of a linear corrugator generally indicated by arrow (300).
• the apparatus (300) includes an endless fluted conveyor surface in the form of an endless slatted conveyor belt assembly (301) which has a plurality of adjacent fluted slats (302) attached to a couple of flexible endless belts (not shown) which is driven by a drive mechanism which has a motor (not shown) and a pair of drive sprockets (303).
• the endless conveyor belt assembly has a number of dummy rollers (304) which keep the endless belt (not shown) and slats (302) on the bottom surface at a fixed height relative to an endless tensioned belt assembly (350).
• the drive mechanism and rollers of the endless tensioned belt assembly (350) are not shown given such arrangements are well known in the art.
• the endless slatted conveyor belt assembly (301 ) has a vacuum pump (305) which can apply a vacuum to freshly corrugated sheet material in the form of Kraft paper (not shown) which has just passed in between corrugating roller (306) and endless slatted conveyor belt assembly (301 ). Apertures in the form of slots (307) in the slats (302) allow the vacuum to be imparted onto the corrugated Kraft paper.
• the corrugated Kraft paper After exiting the corrugating roller (306) the corrugated Kraft paper has a controlled amount of adhesive (not shown) applied to the apex contact portions (not shown) of the crests (not shown) via a glue roller (308) which has a grooved surface (not depicted).
• this glue roller (308) may also be the same as that described as being suitable for, as well as that actually depicted, in the embodiment shown in Figures 2, 3 and 4.
• Adhesive is taken from a glue tray (not shown) and transferred to the glue roller (308) via a glue pick-up roller (309).
• the glue roller (308) may preferably be configured to be capable of being moved laterally with respect to the tensioned belt assembly (310) so as to be adjustable in order to accommodate smaller width paper.
• a planar sheet of material in the form of Kraft paper liner (not shown) is introduced in between the slatted conveyor belt assembly (301) and the endless tensioned belt assembly (350) at the point indicated by arrow (310).
• the length (i.e. the extent) that the slatted conveyor belt assembly (301) and endless tensioned belt assembly (350) overlap represents the DHT.
• FIG 6 shows a portion of an apparatus for manufacturing double face corrugated sheet material generally indicated by arrow (400).
• the apparatus (400) has a single face corrugating module in the form of a linear corrugator (401) substantially as described above in relation to Figure 5.
• Kraft paper (402) to be corrugated enters the linear corrugator (401) as shown and Kraft paper (403) which will form the liner enters the linear corrugator after the glue rollers (407) as shown.
• a laminator module in the form of a double facer (404).
• the double facer (404) has two endless opposed tensioned belt assemblies (405,406) and a glue applicator and nip roller assembly (407) through which the single face corrugated board passes before entering the double facer (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 face liner enters the apparatus (400) and travels along the top of the endless slatted conveyor (410) of the linear corrugator (401) before it enters the double facer (404) together with the single face corrugated board at the point indicated by arrow (409).
• planar sheet material used in the embodiments shown in Figures 5 and 6 can in some embodiments be preprinted with high quality graphic images and/or text .
• planar sheet material (403) and (408) can be pre-printed.
• Figure 10 shows a portion of an apparatus for manufacturing double face corrugated sheet material generally indicated by arrow (1000).
• the apparatus
• (1000) has a single face corrugating module in the form of a linear corrugator
• the double facer (1004) has two endless opposed tensioned belt assemblies (1005,1006) and a glue applicator and nip roller assembly (1007) through which the single face corrugated board (not shown) produced by the linear corrugators (1001) passes before entering the double facer (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 face liner enters the apparatus (1000) and travels along the top of the endless fluted conveyor surface (1010) of the linear corrugator (1001) before it enters the double facer (1004) together with the single face corrugated board at the point indicated by arrow (1009).
• the endless conveyor surface (1010) is formed from fluted bars (1011) - as shown in Figure 11 as opposed to fluted slats as shown in Figure 5 - which are again arranged to form an endless belt.
• the fluted bars (1011) have connection portions in the form of a pair of apertures (1012) at either end thereof which can receive pins (not shown) to join adjacent bars (1011) to one another to form the belt (1010)
• the fluted bars (1011 ) are shown in greater detail in Figures 12 -14 and in particular the fluted top surface (1012) of the bar (101 1).
• the linear corrugator (1001) has belt (1010) driven via the rotation of corrugating roller (1020) (via a motor not shown) such that the teeth of the roller (1021) engage with the flutes (1012) of the bars (1011) to move the belt (1010).
• further motion can be imparted to the belt via toothed drive wheels (1015) are driven by a separate motor (not shown) so that the teeth (1016) may engage with pins connecting the bars (1011) through the gaps (1017) between laterally adjacent bars (1011) in the belt (1010).
• the gaps (1017) also facilitate the application of a vacuum through the conveyor in a similar manner to that already described above in relation to Figure 5.
• a diameter of 2m is at or near the limit at which corrugated cardboard can be created via a pair of intermeshing corrugating rollers: such as described herein, shown in Figure 2 or as described in the applicant's previous PCT

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Machines For Manufacturing Corrugated Board In Mechanical Paper-Making Processes (AREA)
• Laminated Bodies (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)
• Replacement Of Web Rolls (AREA)
• Registering, Tensioning, Guiding Webs, And Rollers Therefor (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=44712440

Family Applications (1)

Country Status (12)

Families Citing this family (21)

Citations (8)

Family Cites Families (18)

• 2011
  • 2011-03-31 CN CN201180015633.4A patent/CN102821936B/zh not_active Expired - Fee Related
  • 2011-03-31 KR KR1020127028685A patent/KR20130114562A/ko not_active Application Discontinuation
  • 2011-03-31 JP JP2013502518A patent/JP2013523492A/ja active Pending
  • 2011-03-31 SG SG10201501327YA patent/SG10201501327YA/en unknown
  • 2011-03-31 EP EP11763109.3A patent/EP2552686A4/de not_active Withdrawn
  • 2011-03-31 RU RU2015156631A patent/RU2015156631A/ru not_active Application Discontinuation
  • 2011-03-31 CN CN201410250869.1A patent/CN104129105A/zh active Pending
  • 2011-03-31 MX MX2012010703A patent/MX348400B/es active IP Right Grant
  • 2011-03-31 SG SG2012070884A patent/SG184242A1/en unknown
  • 2011-03-31 SG SG10201501317WA patent/SG10201501317WA/en unknown
  • 2011-03-31 BR BR112012024867A patent/BR112012024867A2/pt not_active IP Right Cessation
  • 2011-03-31 CN CN201410610783.5A patent/CN104476827A/zh active Pending
  • 2011-03-31 WO PCT/NZ2011/000044 patent/WO2011122968A1/en active Application Filing
• 2012
  • 2012-09-27 CL CL2012002694A patent/CL2012002694A1/es unknown
  • 2012-10-29 ZA ZA2012/08145A patent/ZA201208145B/en unknown
• 2013
  • 2013-05-09 HK HK13105575.7A patent/HK1178489A1/xx not_active IP Right Cessation
  • 2013-05-09 HK HK15101300.6A patent/HK1200773A1/xx unknown
  • 2013-09-10 CL CL2013002595A patent/CL2013002595A1/es unknown
  • 2013-09-10 CL CL2013002596A patent/CL2013002596A1/es unknown
  • 2013-10-24 ZA ZA2013/07972A patent/ZA201307972B/en unknown
• 2015
  • 2015-06-10 JP JP2015117509A patent/JP2015178279A/ja not_active Withdrawn
• 2017
  • 2017-03-06 JP JP2017041446A patent/JP2017124630A/ja active Pending

Patent Citations (8)

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events