NZ607894B2 - Improvements in and Relating to Paperboard Manufacture - Google Patents

Abstract

607894 A machine (1000) for producing corrugated paperboard (1004) is disclosed. The machine includes an endless fluted conveyor belt assembly having an endless fluted conveyor belt (102). The belt has a plurality of adjacent flutes thereon wherein the flutes are configured to correspond to the teeth on a corrugating roller which is located at the upstream end of the endless fluted conveyor assembly. At least one source of electromagnetic radiation (111) and associated support surface is located downstream of a glue applicator (110). The associated support surface is also positioned substantially parallel to the plane of the endless fluted conveyor belt. The associated support surface is capable of at least partially holding the newly glued planar sheet and corrugated sheet material together. An additional laminating station (200) may be downstream of the corrugating machine to apply a second liner sheet to the corrugated paper board. An industrial inkjet printer (1001) may be positioned to print a planar liner before it is glued to the corrugated paperboard. A galvo-head laser (1003) unit may positioned to cut paperboard exiting the machine. th on a corrugating roller which is located at the upstream end of the endless fluted conveyor assembly. At least one source of electromagnetic radiation (111) and associated support surface is located downstream of a glue applicator (110). The associated support surface is also positioned substantially parallel to the plane of the endless fluted conveyor belt. The associated support surface is capable of at least partially holding the newly glued planar sheet and corrugated sheet material together. An additional laminating station (200) may be downstream of the corrugating machine to apply a second liner sheet to the corrugated paper board. An industrial inkjet printer (1001) may be positioned to print a planar liner before it is glued to the corrugated paperboard. A galvo-head laser (1003) unit may positioned to cut paperboard exiting the machine.

Description

JAWS Ref: 237594NZCOG/14 JV IMPROVEMENTS IN AND RELATING TO PAPERBOARD MANUFACTURE TECHNICAL FIELD The present ion relates to improvements in and relating to paperboard manufacture.

BACKGROUND ART In the manufacture of conventional corrugated paperboard the corrugated sheet material is formed by g the paper to be corrugated in between two corrugating rollers.

This is illustrated in the ary example depicted in Figure 1 which is taken from US 4,447,285. In Figure 1 it can be seen the paper after being meshed between the two intermeshing rollers travels at least partially around one of the rollers to enable the newly formed paper flutes to remain in contact with the corrugations of the roller following formation.

This retention of the newly fluted paper against the corrugations of the corrugating roller - post intermeshing of the paper between the opposed ating rollers — helps to reduce ation of the newly imparted flute e to the paper: prior to lamination to a planar liner sheet. In addition, this retention enables a glue roller to contact the flute tips without deforming the flutes as they are resting on the corrugated teeth of the corrugating roller; and this also enables a pressure roller to t and apply pressure to the flute tips, as the liner sheet is brought into contact, to form single face corrugated paperboard.

However, a drawback of conventional ators as shown in Figure 1 is that they turn the freshly corrugated medium through at least 90°C or more, as it travels around one of the ator rollers. The reason why this turning is a drawback, is that it places the paper under undue tension which in turn causes some flattening of the corrugations.

It is an object of the present invention to address the foregoing problems or at least to provide the public with a useful choice.

All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any nce constitutes prior art. The sion of the references states what their authors , and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the JAWS Ref: 237594NZCOG/14 JV common general knowledge in the art, in New Zealand or in any other y. hout this specification, the word "comprise", or ions thereof such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element, r or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, rs or steps.

Further aspects and ages of the present invention will become apparent from the ensuing description which is given by way of example only.

DEFINITIONS The term ‘associated support surface’ as used herein refers to a substantially planar surface from or h which omagnetic magnetic radiation is, or can be, emitted, r directly or indirectly.

The term ‘industrial inkjet printer’ as used herein refers to a single pass high speed inkjet printer which has a printer head which has an array of nozzles which span the width of the material to be printed and preferably includes a heat source.

SUMMARY OF INVENTION According to a first aspect there is provided a machine for producing corrugated paperboard which includes: - an endless fluted conveyor belt assembly having an endless fluted conveyor belt including a plurality of adjacent flutes thereon wherein the flutes are configured to correspond to the teeth on a corrugating roller which is located at the upstream end of the endless fluted conveyor assembly; — at least one source of electromagnetic ion and associated support surface located downstream of a glue applicator, the ated support surface also positioned substantially parallel to, the plane of the endless fluted conveyor belt said associated support surface also being sufficiently proximate to the flutes on the endless fluted conveyor belt, so as in use, to be capable of at least partially holding newly glued planar sheet and corrugated sheet material together.

JAWS Ref: 237594NZCOG/14 JV According to a second aspect of the present invention there is provided a machine for producing ated paperboard ntially as bed above wherein the associated t surface covers a source of electromagnetic radiation.

According to a third aspect of the present invention there is provided a machine for producing corrugated paperboard substantially as described above wherein the associated support surface is also the source of electromagnetic radiation itself.

According to a fourth aspect of the present invention there is provided a machine for producing corrugated paperboard substantially as described above wherein the source of electromagnetic radiation and associated support surface are located adjacently ream of a redirect bar which brings the planar sheet into contact with droplets of glue on the crests of the corrugated sheet material.

According to a fifth aspect of the t invention there is provided a e for producing corrugated paperboard substantially as described above wherein the associated support surface is located ntly downstream of a ct bar which brings the planar sheet into contact with droplets of glue on the crests of the corrugated sheet material.

According to a sixth aspect of the present invention there is provided a machine for producing corrugated paperboard substantially as described above wherein the machine includes an endless tensioned belt assembly which holds planar sheet material and the corrugated sheet material together so a bond is formed there between which is located adjacently downstream of the source of omagnetic radiation and associated support surface.

According to a seventh aspect of the present invention there is provided a machine for producing corrugated paperboard substantially as described above wherein the machine includes a laminator module comprising: - upper and lower opposed contact surfaces at least one being in the form of a tensioned conveyor belt, the upper and lower opposed contact es, in use, being configured to e and press there between: a) planar sheet material; and b) single face corrugated sheet material from the ator module; and JAWS Ref: 237594NZCOG/14 JV - a glue applicator for ng adhesive to the single face corrugated board and/or planar sheet material prior to travelling between the upper and lower contact surfaces which hold the planar sheet material and single face corrugated board together so a bond is formed there between; and - wherein either the upper or the lower opposed contact surface includes as part thereof, or is formed from, at least one source of electromagnetic radiation and ated support said associated support surface being positioned so as to at least lly hold newly glued double face sheet al together.

According to the eighth aspect there is provided a corrugated sheet material substantially as described above. According to a ninth aspect there is provided a machine for producing corrugated paperboard substantially as described above wherein the machine includes an inkjet printer which is positioned to print a planar liner sheet prior to the liner sheet being bonded to a corrugated sheet material.

According to a tenth aspect there is provided a machine for producing ated paperboard ntially as described above wherein the machine includes a galvo-head laser unit oned to cut paperboard exiting the machine.

According to a eleventh aspect there is provided a machine for producing corrugated paperboard via a process not requiring steam which includes an industrial inkjet printer which is oned to print a liner sheet prior to the liner sheet being bonded to a corrugated .

According to a twelfth aspect there is provided a machine for producing corrugated paperboard via a s not ing steam which includes a galvo-head laser unit positioned to cut paperboard exiting the machine.

According to a thirteenth aspect there is provided a method of increasing the speed of a machine for producing corrugated paperboard via a process not requiring steam via use: - an upstream industrial inkjet printer; to warm the liner sheet prior to bonding to a corrugated medium.

JAWS Ref: 237594NZCOG/14 JV BRIEF DESCRIPTION OF THE DRAWINGS Further aspects of the present invention will become apparent from the ensuing description which is given by way of example only and with reference to the accompanying drawings in which: Figure 1 shows exemplary prior art corrugator taken from Figure 2 of US4,447,285.

Figure 2 shows a schematic perspective view of a single face linear ator in accordance with one aspect of the present invention; Figure 3 shows a side view of a double face linear corrugator in ance with another aspect of the present invention; Figure 4 shows a schematic side view of a double face linear corrugators in accordance with r aspect of the present invention.

BEST MODES AND ILLUSTRATIVE EXAMPLES Figure 2 shows an apparatus for manufacturing single face ated sheet material in the form of a single face linear corrugator generally indicated by arrow (100). Figure 3 shows the single face corrugator (100) of Figure 2 fitted with a double facer laminating station. For ease of reference the paper sheets used in the corrugator (100) are shown in Figure 3 and not Figure 1.

In Figure 2 the single face linear corrugator (100) has an endless slatted conveyor belt assembly (101) having an s fluted conveyor belt (102) — (formed from a plurality of adjacent fluted slats (not shown)) - which is driven by a drive mechanism having a motor (not shown) and drive sprockets (103). The endless conveyor belt assembly (101) has a number of dummy rollers (104) which keep the or belt (102) pressed onto: - an associated support surface in the form of a sheet quartz glass (111) which covers a source of electromagnetic radiation in the form of a bank of medium wave infrared s (112) which span: across the width of the corrugator, and along the length of the glass 111 in the direction in which the newly glued single face paperboard travels; and - an endless tensioned belt assembly (150).

The drive mechanism and rollers of the endless tensioned belt assembly (150) are not shown given such arrangements are well known in the art.

JAWS Ref: 237594NZCOG/14 JV The linear single face corrugator (100) has a corrugating roller (106) which is formed by a number of spaced apart adjacent ating discs which are located a spindle (198). In between each of the corrugating discs are support fingers (199) which hold the Kraft paper to be ated (180) against the fluted slats on the endless fluted conveyor belt (102) as the paper (180) enters the corrugator (100).

The endless slatted conveyor belt assembly (101) has a vacuum pump (105) 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 (106) and endless slatted conveyor belt (102). Gaps between the adjacent slats allow the vacuum to be imparted onto the corrugated Kraft paper - this feature is known in the art and is shown in Figure 11 of the applicant’s earlier patent application. .

After g the corrugating roller (106) 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 (108) which has a helically grooved surface (not depicted). In use, adhesive is taken from a glue tray (not shown) and transferred to the glue roller (108) via a glue pick-up roller (109).

A planar sheet of al in the form of Kraft paper (herein the "first liner sheet") (181) passes around a redirect bar (110) and is feed between the endless fluted conveyor surface (102) and the associated support surface (111). The redirect bar (110) as well as a set of dummy rollers (104) in conjunction with surface (102) apply pressure to the corrugated paper and liner sheet to hold them together until the bond is at least partially formed.

Additionally, the heat from the medium wave IR heater (112) helps set the glue which will hold the corrugated paper to the liner sheet to form single face paperboard (182). To further ensure a bond has formed between the ated paper and the liner sheet the newly formed single face paperboard (182) then s along endless tensioned belt assembly (150). The length of the source of electromagnetic ion and associated support surface (111) relative to the direction in which the newly formed corrugated paperboard travels, s on the speed at which the newly formed corrugated oard is travelling, and bond time of the adhesive used.

JAWS Ref: 237594NZCOG/14 JV Figure 3 shows a double facer apparatus as ted by arrow (200). The apparatus (200) situated below a single face corrugating module in the form of a linear corrugator (100) substantially as described above in relation to Figure 2.

As can be seen Kraft paper (180) to be corrugated enters the linear corrugator (100) upstream of corrugating (106) and Kraft paper (181) which will form the first liner sheet enters the linear corrugator (100) after the glue s (108,109) as shown.

The double facer (200) has d upper and lower contact surfaces which are in the form of endless opposed ned belt assemblies (201,202) and a glue applicator and nip roller assembly (203) h which the single face corrugated board (182) passes before entering the double facer (200). The glue roller assembly (203) is substantially the same as that described in relation to Figure 2. The Kraft paper (183) which forms the double face liner sheet enters the apparatus (200) and travels above the top of the endless slatted conveyor (101 ) of the linear corrugator (100) on support bars (204) before it enters the double facer (200) er with the single face corrugated board at the point indicated by arrow (205).

The double facer (200) also has as part of the lower t surface an associated support surface (206) positioned above an source of electromagnetic radiation in the form of a bank of medium wave infrared heaters (207) positioned adjacent and downstream of the redirect bar (208) which directs the liner sheet (183) into the double facer (200).

It will be appreciated by those skilled in the art that the planar sheet material used in the embodiments shown in Figures 2 and 3 can in some embodiments be pre-printed with high quality graphic images and/or text . For example, in Figure 3 the planar sheet material (183) can be pre-printed.

In Figure 4 there is an apparatus (1000) for producing double face corrugated paperboard. The apparatus is similar to that shown in Figure 3 but includes a number of further features: First, the apparatus (1000) includes an industrial UV inkjet printer (1001) manufactured by XAAR aar.com) through which first liner sheet (1002) passes before going around redirect bar (110) and being fed between the endless fluted conveyor surface (102) and associated support surface (111).

Second, the apparatus (1000) includes a galvo-head CNC laser station (1003) which receives double face board (1004) exiting the double facer (200). The head CNC laser station JAWS Ref: 237594NZCOG/14 JV (1003) cuts, scores or marks the double face board according to the product that is sought to be produced as pre—programmed. For example, the galvo-head CNC laser station can produce box blanks (1005) or other ated product blanks (not shown). The galvo-head CNC laser station includes an optical scanner which enables the laser to track the varying speed of the paperboard.

This embodiment has a number of features which provides additional advantages which can include: - the ability to print high quality c images as part of a continuous or line s for the manufacture of paperboard; - the ability to increase the speed at which printed paperboard is produced; - the ability to increase the speed of the oard manufacturing s when the industrial inkjet printer has a heat source which pre-heats the liner sheet which reduces the cure time for the adhesive; and - the y to produce boxes which are pre-printed as part of a continuous process for the manufacture of paperboard.

DETAILED DISCUSSION OF ALTERNATE WAYS TO IMPLEMENT THE INVENTION The electromagnetic radiation source may include any source electromagnetic radiation capable of ly or indirectly heating paper and/or heating or curing adhesive suitable for bonding sheets of paper to one another.

In some embodiments there may be two or more different types of electromagnetic radiation.

For example, there may be infrared radiation and UV radiation sources.

In some embodiments the additional types of radiation source may be utilised for purposes other than curing the adhesive.

In one embodiment the electromagnetic radiation source may be a medium wave IR heater.

In another ment the electromagnetic radiation source may be a medium wave carbon infrared heater.

JAWS Ref: 237594NZCOG/14 JV In a further embodiment the electromagnetic radiation source may be a medium wave quartz infrared heater.

In a further embodiment the electromagnetic radiation source may be medium wave IR LEDs.

In another embodiment the electromagnetic radiation source may be a medium wave ceramic IR heater.

In still a further embodiment the electromagnetic ion source may be a UV lamp.

The associated support surface may come in a y of different forms without departing from the scope of the t invention.

In one embodiment the associated support surface may have a continuous uninterrupted t surface provided said surface emits electromagnetic radiation, or allows electromagnetic radiation, to pass hrough.

In another ment the associated support surface may have a number of holes or slots therein which allow electromagnetic ion to pass therethrough. The holes and slots being arranged so the ated support surface is still capable of supporting the newly formed ated single face or double face paperboard.

In one embodiment the associated support surface may be CLEARCERAMTM glass-ceramic.

In another embodiment the associated support may be a quartz glass.

In some embodiments the glass may be a low thermal expansion glass.

The associated support surface may preferably be arranged to be capable of being raised or lowered with respect to the s fluted conveyor. This ability to move the associated support surface towards and away from the endless fluted conveyor provides a number of advantages, two non-limiting examples are: — adjusting the degree of pressure placed on the planar and ated sheet materials during the lamination process; and - allowing the EMR surface to be automatically moved away from contact with the planar and corrugated sheet materials if the machine is stopped so as to lessen any risk of fire.

JAWS Ref: 237594NZCOG/14 JV Aspects of the present invention have been described by way of example only and it should be appreciated that cations and additions may be made thereto without departing from the scope thereof as defined in the appended claims.

JAWS Ref: 237594NZCOG/14 JV

Claims (9)

WHAT WE CLAIM IS:

1. A machine for ing corrugated paperboard which es: an endless fluted conveyor belt assembly having an endless fluted conveyor belt including a plurality of adjacent flutes thereon wherein the flutes are configured to correspond to the teeth on a corrugating roller which is located at the upstream end of the endless fluted conveyor assembly; — at least one source of electromagnetic radiation and associated support surface d downstream of a glue ator, the associated support surface also positioned substantially parallel to, the plane of the endless fluted conveyor belt said associated support surface also being sufficiently ate to the flutes on the endless fluted conveyor belt, so as in use, to be capable of at least lly holding newly glued planar sheet and corrugated sheet material together; and - wherein the machine further includes an industrial inkjet printer which is positioned to print a planar liner sheet prior to the liner sheet being bonded to a corrugated sheet material.

2. A machine for producing corrugated paperboard as d in claim 1 wherein the associated support surface covers a source of omagnetic radiation.

3. A e for producing corrugated paperboard as claimed in claim 1 wherein the associated support surface is also the source of electromagnetic radiation itself.

4. A machine for producing corrugated paperboard as claimed in any one of the preceding claims wherein the source of electromagnetic radiation and associated support surface are d adjacently downstream of a ct bar which brings the planar sheet into contact with droplets of glue on the crests of the corrugated sheet material.

5. A machine for producing corrugated paperboard as claimed in any one of claims 1—3 n the associated support surface is located adjacently downstream of a redirect bar which brings the planar sheet into contact with droplets of glue on the crests of the corrugated sheet material. JAWS Ref: 237594NZCOG/14 JV

6. A machine for ing corrugated paperboard as d in any one of the preceding claims n the machine includes an endless tensioned belt assembly which holds * planar sheet material and the corrugated sheet material together so a bond is formed there between which is located adjacently downstream of the source of electromagnetic radiation and associated support surface.

7. A machine for producing corrugated paperboard as claimed in claim 1 wherein the machine includes a laminator module comprising: - upper and lower opposed contact surfaces at least one being in the form of a tensioned conveyor belt, the upper and lower opposed contact surfaces, in use, being configured to receive and press there between: a) planar sheet material; and b) single face corrugated sheet material from a corrugator module; and - a glue applicator for applying adhesive to the single face corrugated board and/or planar sheet material prior to travelling between the upper and lower contact surfaces which hold the planar sheet al and single face corrugated board together so a bond is formed there between; and - wherein either the upper or the lower opposed contact surface es as part thereof, or is formed from, at least one source of electromagnetic radiation and ated support surface said associated support surface being oned so as to at least partially hold newly glued double face sheet material together; and - wherein the machine further includes an industrial inkjet printer which is positioned to print a planar liner sheet prior to the liner sheet being bonded to a corrugated sheet material.

8. A corrugated sheet al produced by the machine as d in any one of the preceding claims. JAWS Ref: 237594NZCOG/14 JV

9. A machine for producing corrugated paperboard as claimed in claim 1 or claim 7 wherein the machine includes a galvo-head laser unit positioned to cut paperboard exiting the machine. Corcel lP Limited; by its Attorneys m)MW‘K.‘2””vaé» «Why; James & Wells ectual Property