AU2006235890A1

AU2006235890A1 - Method of Applying an Image to a Sheet of Paper-Based Material

Info

Publication number: AU2006235890A1
Application number: AU2006235890A
Authority: AU
Inventors: George Ganzenmuller
Original assignee: AMCOR Ltd
Current assignee: Opal Packaging Australia Pty Ltd
Priority date: 2005-11-07
Filing date: 2006-11-06
Publication date: 2007-05-24
Anticipated expiration: 2026-11-06
Also published as: AU2006235890B2

Description

Name of Applicant: Actual Inventor: Address for Service: Invention Title: Details of Associated Provisi

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Amcor Limited George Ganzenmuller CULLEN CO Patent Trade Mark Attorneys, 239 George Street Brisbane Qld 4000 Australia Method of Applying an Image to a Sheet of Paper-Based Material onal Application: 2005906143 filed 7 November 2005 The following statement is a full description.of this invention, including the best method of performing it, known to us: IND 2 c Technical Field The present invention relates generally to printing and, in particular, to the Z application of printed images to corrugated paperboard.

Background Art The corrugated paperboard from which corrugated boxes are fabricated is 00 00 commonly manufactured from linerboard and corrugating medium using a corrugator machine. The liner and the corrugating medium are usually stored on large rolls and are usually fed to the corrugator from these rolls. As the corrugating medium passes C 10 through the corrugator, flutes or corrugations are formed in the corrugating medium by the machine. The corrugator then glues the liner to one or both sides of the corrugating medium. Prior to gluing, the corrugator heats either or both the corrugating medium and the liner to improve the adhesion of the glue to the corrugating medium or the liner.

A printing process such as a flexographic or gravure printing process is often used to apply printed matter to the linerboard prior to the linerboard being fed into the corrugator and adhered to the corrugating medium. A problem with pre-printing the linerboard before the linerboard is fed into the corrugator is that the print on the liner can be adversely affected by the heat which is applied to the corrugating medium or the liner prior to the corrugating medium and the liner being glued together by the corrugator. For example, the print may run or it may be smudged after heat is applied by the corrugator to the corrugating medium or the liner.

The quality of the print on the linerboard is dependent to a certain extent on the properties of the printed surface of the linerboard. For example, if the printed surface of the linerboard is a porous paper surface, the printing will usually not be as sharp as it would be if the printing was applied to a less porous surface such as a polymer surface.

It would therefore be desirable to be able to print on a corrugated paperboard liner prior to the liner being adhered to the corrugating medium of the paperboard without the print being adversely affected by the heat which is applied to the corrugating medium or the liner by a corrugator machine prior to the corrugating O 3 medium and the liner being glued together.

It would also be desirable to have a corrugated paperboard liner which has a Z printing surface which is conducive to high-quality printing.

Disclosure of the Invention It is an object of the present invention to overcome, or at least ameliorate, 00 00one or more of the deficiencies of the prior art mentioned above, or to provide the consumer with a useful or commercial choice.

Other objects and advantages of the present invention will become apparent C 10 from the following description, taken in connection with the accompanying illustration, wherein, by way of illustration and example, a preferred embodiment of the present invention is disclosed.

According to a first broad aspect of the present invention there is provided a method of applying an image to a sheet of corrugated paperboard, the method comprising the steps of: printing the image on a surface of a sheet of transparent polymer; (ii) laminating a sheet of paper with the transparent polymer sheet such that the printed surface of the polymer sheet faces the paper sheet; and (iii) laminating a corrugated sheet of corrugating medium with the paper sheet.

The laminated transparent polymer and paper sheets form a linerboard of the corrugated paperboard. The linerboard is preferably an outside linerboard of the corrugated paperboard.

The image which is printed on the polymer sheet is able to be viewed through a surface of the polymer sheet on which the image is not printed by virtue of the transparency of the polymer sheet.

If, a corrugating machine is used to laminate the corrugating medium with the linerboard which includes the laminated transparent polymer sheet and the paper sheet, the print on the polymer sheet is less likely to be adversely affected by the heat which is applied by the corrugator to the liner or the corrugating medium because the print is located between the polymer sheet and the paper sheet and is unable to contact O 4 Sthe corrugator.

The printing surface of the polymer sheet is more conducive to high-quality Z printing than the paper sheet.

NThe sheet of corrugated paperboard may be any suitable type of corrugated paperboard. For example, the corrugated paperboard may be single or double faced corrugated paperboard, twin cushion corrugated paperboard, triple flute corrugated 00 00 paperboard or Duo Arch corrugated paperboard.

SAny type of image may be applied to the corrugated paperboard. For

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example, the image may include letters, numbers, logos, photos, or any combination S 10 thereof.

The image may be printed on the transparent polymer sheet using any suitable printing process. For example, the image may be printed on the transparent polymer sheet by a flexographic or gravure printing process.

Preferably, the image is reverse printed on the transparent polymer sheet so that the correct image is able to be viewed through a surface of the polymer sheet on which the image is not printed.

The transparent polymer sheet may be a sheet of any suitable type of transparent polymer. Preferably, the transparent polymer sheet is a sheet of transparent polyethylene terephthalate (PET).

The paper sheet may be a sheet of any suitable type of paper. For example, the paper sheet may be a sheet of kraft paper. In a particular preferred form, the paper sheet is a sheet of 80 or 100 gsm kraft paper.

Preferably, the printed surface of the transparent polymer sheet is laminated with an intermediate polymer sheet, and the paper sheet is laminated with the intermediate polymer sheet so that the intermediate polymer sheet is located between the transparent polymer sheet and the paper sheet.

The intermediate polymer sheet may be a sheet of any suitable type of polymer. Preferably, the intermediate polymer sheet is a sheet of medium density polyethylene (MDPE) which is a blend of low density polyethylene (LDPE) and high density polyethylene (HDPE).

In another preferred form, the transparent polymer sheet on which the image O is printed is adhered directly to the paper sheet.

>The printed surface of the transparent polymer sheet may be laminated with Z the paper sheet in any suitable manner. Preferably, the transparent polymer sheet is Ilaminated with the paper sheet before the resultant linerboard is fed into a corrugator machine to be laminated with the corrugating medium.

According to a second broad aspect of the present invention there is provided 00 0t a sheet of corrugated paperboard comprising a sheet of transparent polymer, an image printed on a surface of the transparent polymer sheet, a sheet of paper laminated with the transparent polymer sheet such that the printed surface of the polymer sheet faces I 10 the paper sheet, and a corrugated sheet of corrugating medium laminated with the paper sheet.

Any type of image may be printed on the transparent polymer sheet. For example, the image may include letters, numbers, logos, photos, or any combination thereof.

The intermediate polymer sheet may be a sheet of any suitable type of IO 6 c polymer. Preferably, the intermediate polymer sheet is a sheet of medium density polyethylene (MDPE).

Z In another preferred form, the transparent polymer sheet on which the image printed is adhered directly to the paper sheet.

According to a third broad aspect of the present invention there is provided a container which is erected from a blank which is fabricated from a sheet of corrugated 00 0n paperboard comprising a sheet of transparent polymer, an image printed on a surface C of the transparent polymer sheet, a sheet of paper laminated with the transparent

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polymer sheet such that the printed surface of the polymer sheet faces the paper sheet, Ci 10 and a corrugated sheet of corrugating medium laminated with the paper sheet.

The container may be any suitable type of container. For example, the container may be a carton or a tray.

Brief Description of the Illustration In order that the invention may be more fully understood and put into practice, a preferred embodiment thereof will now be described with reference to the accompanying illustration, in which figure 1 depicts the layers of a corrugated paperboard sheet according to the preferred embodiment of the present invention.

Best Mode for Carrying Out the Invention Referring to figure 1, a corrugated paperboard sheet 10 includes a sheet 11 of transparent polyethylene terephthalate (PET). An image which is represented by a layer 12 in figure 1 is printed on a surface 13 of sheet 11. The image is reverse printed on the surface 13 of sheet 11 so that the correct image is able to be viewed through the other surface of sheet 11.

The printed surface 13 of sheet 11 is laminated with a sheet 14 of medium density polyethylene (MDPE) 14. Medium density polyethylene is a blend of low density polyethylene (LDPE) and high density polyethylene (HDPE).

A sheet 15 of 80 or 100 gsm kraft paper is laminated with the medium density polyethylene sheet 14.

A corrugated sheet 16 of corrugating medium is laminated with the sheet O 7 so that sheets 11, 14, 15 and 16 form the corrugated paperboard sheet 10. The corrugated paperboard sheet 10 includes a linerboard 17 provided by the laminated Z sheets 11, 14 and Throughout the specification and the claims, unless the context requires otherwise, the term "comprise", or variations such as "comprises" or "comprising", will be understood to apply the inclusion of the stated integer or group of integers but 00 0t not the exclusion of any other integer or group of integers.

SThroughout the specification and claims, unless the context requires

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otherwise, the term "substantially" or "about" will be understood to not be limited to S 10 the value for the range qualified by the terms.

It will be appreciated by those skilled in the art that variations and modifications to the invention described herein will be apparent without departing from the spirit and scope thereof. The variations and modifications as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein set forth.

Any reference herein to prior art is not to be taken as an admission that the referenced prior art is common general knowledge.

Claims

1. A method of applying an image to a sheet of corrugated paperboard, the Z method comprising the steps of: (ii) printing the image on a surface of a sheet of transparent polymer; (ii) laminating a sheet of paper with the transparent polymer sheet such that the printed surface of the polymer sheet faces the paper sheet; and 00 00 (iii) laminating a corrugated sheet of corrugating medium with the paper sheet.

2. The method of claim 1, wherein the image is printed on the transparent NI 10 polymer sheet by a flexographic or gravure printing process.

3. The method of any one of the preceding claims, wherein the image is reverse printed on the transparent polymer sheet.

4. The method of any one of the preceding claims, wherein the transparent polymer sheet is a sheet of transparent polyethylene terephthalate.

5. The method of any one of the preceding claims, wherein the paper sheet is a sheet of kraft paper.

6. The method of claim 5, wherein the paper sheet is a sheet of 80 or 100 gsm kraft paper.

7. The method of any one of the preceding claims, wherein the method includes the further steps of: (iv) laminating the printed surface of the transparent polymer sheet with an intermediate polymer sheet; and laminating the paper sheet with the intermediate polymer sheet.

8. The method of claim 7, wherein the intermediate polymer sheet is a sheet of medium density polyethylene.

9. The method of any one of claims 1 to 6, wherein the transparent polymer sheet is adhered directly to the paper sheet.

The method of any one of the preceding claims, wherein the transparent polymer sheet is laminated with the paper sheet before the corrugated sheet of corrugating medium is laminated with the paper sheet.

11. A sheet of corrugated paperboard comprising a sheet of transparent polymer, N 9 an image printed on a surface of the transparent polymer sheet, a sheet of paper laminated with the transparent polymer sheet such that the printed surface of the \O Z polymer sheet faces the paper sheet, and a corrugated sheet of corrugating medium laminated with the paper sheet.

12. The sheet of claim 11, wherein the transparent polymer sheet is a sheet of transparent polyethylene terephthalate. 00 00

13. The sheet of claim 11 or 12, wherein the image is reverse printed on the Stransparent polymer sheet.

14. The sheet of any one of claims 11 to 13, wherein the paper sheet is a sheet of C 10 kraft paper.

The sheet of claim 14, wherein the paper sheet is a sheet of 80 or 100 gsm kraft paper.

16. The sheet of any one of claims 11 to 15, wherein the sheet further comprises an intermediate polymer sheet between the transparent polymer sheet and the paper sheet.

17. The sheet of claim 16, wherein the intermediate polymer sheet is a sheet of medium density polyethylene.

18. A container which is erected from a blank which is fabricated from a sheet of corrugated paperboard comprising a sheet of transparent polymer, an image printed on a surface of the transparent polymer sheet, a sheet of paper laminated with the transparent polymer sheet such that the printed surface of the polymer sheet faces the paper sheet, and a corrugated sheet of corrugating medium laminated with the paper sheet.

19. A sheet of corrugated paperboard substantially as herein described with reference to figure 1.