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CN-117284008-B - Method for manufacturing printed corrugated board

CN117284008BCN 117284008 BCN117284008 BCN 117284008BCN-117284008-B

Abstract

The invention relates to a method for producing printed corrugated board, comprising the steps of a) providing a paper liner (23) having an ink-receiving layer, and b) inkjet printing an image on the ink-receiving layer with one or more pigmented aqueous inkjet inks using a piezo-through printhead (25) having nozzles with an outer nozzle surface area NS of less than 500 [ mu ] m 2 , wherein the one or more pigmented aqueous inkjet inks contain water in an amount of A% by weight defined by wherein the% by weight is based on the total weight of the aqueous inkjet ink, wherein sqrt (NS) represents the square root of the outer nozzle surface area NS, and wherein A% by weight is not less than 40% by weight.

Inventors

  • S. De MUTEL
  • LENAERTS JENS

Assignees

  • 爱克发有限公司

Dates

Publication Date
20260505
Application Date
20200910
Priority Date
20190925

Claims (20)

  1. 1. A method of manufacturing printed corrugated board, the method comprising the steps of: a) Providing a paper backing (23) with an ink-receiving layer, and B) Ink jet printing an image on the ink receiving layer with one or more pigmented aqueous inkjet inks using a piezo-through flow printhead (25) having nozzles with an outer nozzle surface area NS of less than 500 μm 2 ; wherein the one or more pigmented aqueous inkjet inks contain water in an amount of a wt% defined by formula (I): 100wt%-sqrt(NS)x3.8wt%/μm≤Awt%≤100wt%-sqrt(NS)x2.2wt%/μm Formula (I) Wherein the wt% is based on the total weight of the aqueous inkjet ink; wherein sqrt (NS) represents the square root of the outer nozzle surface area NS, and Wherein A is greater than or equal to 40% by weight, and Wherein the application of the ink-receiving liquid for forming the ink-receiving layer is performed by inkjet.
  2. 2. A method of manufacture as claimed in claim 1, comprising the step c) of laminating an ink-jet printed paper liner (27) to the fluted board of the corrugated board.
  3. 3. The manufacturing method according to claim 1, wherein the inkjet printing is performed according to a single pass printing method.
  4. 4. The production method according to claim 1, wherein the ink-receiver liquid comprises an acidic compound or a polyvalent cation compound.
  5. 5. The method of manufacturing of claim 1, comprising the step of applying a protective varnish layer over the inkjet printed image.
  6. 6. The method of manufacture of claim 5, wherein the protective varnish layer is applied by inkjet.
  7. 7. The method of manufacturing of claim 1, wherein the outer nozzle surface area NS is less than 300 μιη 2 .
  8. 8. The method of manufacture of claim 1, wherein the one or more aqueous inkjet inks have a viscosity between 3.0 and 8.0mpa.s at 32 ℃ at a shear rate of 1,000s -1 .
  9. 9. The production method according to claim 1, wherein a dry weight of the ink-receiving layer is less than 0.8g/m 2 .
  10. 10. A manufacturing method as claimed in claim 1, wherein the paper backing (23) is provided in the form of a roll.
  11. 11. The manufacturing method according to claim 1, wherein the colored aqueous inkjet ink includes: a) A cyan aqueous inkjet ink containing a β -copper phthalocyanine pigment; b) A magenta or red aqueous inkjet ink containing a pigment selected from the group consisting of c.i. pigment red 57/1, c.i. pigment red 122, c.i. pigment violet 19 and mixed crystals thereof; c) A yellow aqueous inkjet ink containing a pigment selected from the group consisting of C.I. pigment yellow 74, C.I. pigment yellow 138, C.I. pigment yellow 151, and mixed crystals thereof, and D) A black aqueous inkjet ink containing a carbon black pigment.
  12. 12. The manufacturing method according to claim 1, wherein the paper backing (23) has a white color.
  13. 13. The method of manufacturing of claim 1, wherein the printed corrugated board is single wall corrugated board.
  14. 14. An inkjet printing apparatus for manufacturing printed corrugated board, the apparatus comprising: a) A piezo-electric through-flow printhead having nozzles with an outer nozzle surface area NS of less than 500 μm 2 , and B) An aqueous inkjet ink from an aqueous inkjet ink set, wherein the aqueous inkjet ink contains water in an amount of a wt% defined by formula (I): 100wt%-sqrt(NS)x3.8wt%/μm≤Awt%≤100wt%-sqrt(NS)x2.2wt%/μm Formula (I) Wherein the wt% is based on the total weight of the aqueous inkjet ink; wherein sqrt (NS) represents the square root of the outer nozzle surface area NS, and Wherein the weight percent of A is more than or equal to 40 percent.
  15. 15. The inkjet printing apparatus of claim 14 which is a single pass inkjet printing apparatus.
  16. 16. The inkjet printing apparatus of claim 15, wherein the single pass inkjet printing apparatus uses a plurality of staggered inkjet printheads.
  17. 17. The inkjet printing apparatus of claim 15 wherein a wt% is equal to or greater than 44 wt%.
  18. 18. The inkjet printing apparatus of claim 15 wherein the outer nozzle surface area NS is less than 300 μm 2 .
  19. 19. The inkjet printing apparatus of claim 14, wherein the aqueous inkjet ink has a viscosity at 32 ℃ of between 3.0 and 8.0mpa.s at a shear rate of 1,000s -1 .
  20. 20. The inkjet printing apparatus of claim 15, comprising an NIR dryer.

Description

Method for manufacturing printed corrugated board The application is a divisional application of the following application No. 202080067191.7, the application No. 2020, no. 09, no. 10, entitled "method for manufacturing printed corrugated Board". Technical Field The present invention relates to a method for manufacturing printed corrugated board. Background Corrugated board is a preferred packaging material because of its low cost and low weight. Lightweight packaging materials reduce shipping costs and facilitate handling during delivery to customers. A further benefit is that the corrugated cardboard boxes are stackable so that they are easy to store and transport. Corrugated board is a packaging material formed by gluing one or more fluted cardboard sheets (called corrugated medium) to one or more flat liner sheets (called facers). It is of four general types, (1) one fluted sheet glued to one facing layer (two sheets total), (2) single wall: one fluted sheet sandwiched between two facing layers (three sheets total), also known as double or single layer, (3) double wall: one single wall glued to one single wall such that two fluted sheets are alternately sandwiched between three flat sheets (five sheets total), also known as double pad or double layer, and (4) triple wall: two single walls glued to one single wall such that three fluted sheets are alternately sandwiched between four flat sheets (seven sheets total), also known as triple layer. Traditionally, images are printed on corrugated board using flexographic and offset printing techniques. As the role of electronic commerce becomes more and more important, the direct contact of sellers with clients decreases. Companies are researching ways to maintain and enhance customer experience and customer participation. Packaging is becoming a way to achieve this through customized or even personalized messaging. However, printing such messaging by flexographic or offset plates is extremely expensive. A preferred alternative technique is inkjet, which has no printer set-up time (no plates and plate change) and allows for short delivery cycles. Because packaging has a significant impact on consumer purchases, there is a need to improve image quality. For example, EP3360934 a (FUJIFILM) discloses an inkjet ink set for corrugated board, which contains five colors of inks having different hues, whereas four color ink sets consisting of yellow (Y) ink, magenta (M) ink, cyan (C) ink, and black (K) ink have been generally used so far. In addition to image quality, high productivity is also required in an industrial environment. Especially when using a single pass inkjet printing system, the reliability of inkjet printing is of paramount importance. Single pass inkjet machines run at very high speeds, some even up to 150m/min. For example, ink jet ink blocking one or more nozzles causes line artifacts in the printed image, material waste, and interruption of the printing process. This represents not only financial loss but also productivity loss. There remains a need for improved methods for manufacturing printed corrugated board in an economical manner with inkjet printing methods having high reliability and improved image quality. Disclosure of Invention In order to overcome the above problems, a preferred embodiment of the present invention has been achieved by a method of manufacturing printed corrugated board as defined in claim 1. It has surprisingly been found that for certain piezoelectric printheads there is a relationship between the outer nozzle surface area of the nozzles in the printhead and the water content in the aqueous inkjet ink such that reliable inkjet printing is achieved. It is an object of the present invention to provide an improved method of manufacturing printed corrugated board using specific aqueous inkjet inks in a piezo-electric through-flow printhead having nozzles with an outer nozzle surface area NS of less than 500 μm 2. It is another object of the present invention to provide a combination of a piezo-electric through-flow printhead having nozzles with an outer nozzle surface area NS of less than 500 μm 2 with a specific pigmented aqueous inkjet ink from an aqueous inkjet ink set for producing printed corrugated board with high image quality and reliability. These and other objects will become apparent from the detailed description that follows. Drawings Fig. 1 illustrates the structure of a corrugated board formed by gluing a fluted board (1) to a paper liner (2) and a paper liner (3) with glue (4). Fig. 2.A shows a cross section of an end-jet printhead, wherein the printhead wall (10) encloses an ink channel (14) that supplies inkjet ink via an ink inlet (12), which can leave the printhead via ink jets (11) as jetted ink droplets (17) only through nozzles (16) in a nozzle plate (15) of the printhead. The piezoelectric elements of the print head for forming the ejected droplets (17) are not shown in the schematic diagram. Fig. 2.