Ink jet primer applied on corrugated board manufacturing device

Abstract

To provide a UV ink jet receptive primer that can be applied on a corrugated board manufacturing device.SOLUTION: A UV ink jet receptive primer is applied by a corrugated board manufacturing device to produce a UV ink jet printable, continuous folded, corrugated material (e.g. fan fold). Priming is performed in-line by the corrugated board manufacturing device. The primer withstands the heat, humidity, and abrasion of the corrugated board manufacturing device, yielding a surface that can be printed with UV inkjet ink and resulting in a high quality image.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] (Related Applications) This application claims priority to Provisional Patent Application No. 63 / 648,256, filed May 16, 2024, which is incorporated herein by reference in its entirety.

[0002] Various embodiments disclosed herein relate to UV inkjet receptive primers that are applied to corrugating machines. [Background technology]

[0003] UV inkjet printing on paper-based corrugated substrates requires a primer to achieve good quality when printed with UV inkjet inks. Corrugated inkjet printing is typically done in a sheet-fed format, and sheets are primed in-line using a flexographic printing station or analog coating system such as a roller coater.

[0004] Downstream in-line automated processing requires folded continuous corrugated material (called fanfold material).

[0005] Fanfold material cannot be primed using analog methods because the folding process causes coating defects, so the liner must be primed beforehand and then formed into the fanfold shape. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] Metsa Pro, https: / / www.metsagroup.com / metsaboard / products-and-services / products / white-kraftliners / metsaboard-pro-wkl / [Non-patent document 2] Metsa Classic, https: / / www.metsagroup.com / metsaboard / products-and-services / products / white-kraftliners / metsaboard-classic-wkl / [Non-patent document 3] https: / / www.bhs-world.com / en / corrugators / corrugator-lines Summary of the Invention

[0007] UV inkjet receptive primers are applied by the corrugating machine to produce continuous folding corrugated board (e.g., fanfold) that is UV inkjet printable. The priming is done inline with the corrugating machine. The primer is designed to withstand the heat, humidity, and abrasion of the corrugating machine and create a surface that can be printed with UV inkjet inks, resulting in high-quality images.

[0008] An embodiment of the present invention allows for the repurposing of a printing station on a corrugating machine as a primer treatment unit to prime paper during the manufacturing process. This primer prepares fanfold paper for UV inkjet printing. This primer improves print quality by controlling dot spread and absorption of ink or ink components into the paper liner. For typical clay-coated boards, such as those described in References 1 and 2, the primer increases dot gain and produces smooth, uniform solid prints compared to unprimed boards.

[0009] Currently, there is no other way to prepare fanfold paper for inkjet printing. [Brief explanation of the drawings]

[0010] [Figure 1]1 is a schematic diagram of a corrugated cardboard manufacturing machine in which a primer is applied in-line, according to one embodiment of the present invention. [Figure 2] 2 is a detailed schematic diagram of a portion of the corrugated cardboard manufacturing machine of FIG. 1 according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The invention disclosed herein uniquely provides a method and apparatus for priming fanfold corrugated board for inkjet printing. One of the technical challenges in priming such board for UV inkjet inks prior to converting and fanfolding is the need to maintain surface quality and uniformity of surface energy even under the harsh corrugating conditions of temperatures exceeding 135°C, steam, and abrasion. An example of a corrugating machine can be found at the link in Citation 3.

[0012] Although the priming process can be performed offline in a subsequent corrugating process, it is preferable to perform the process inline by connecting a coating station directly to the corrugating machine. Inline coating is preferred because it requires less logistics and paper roll movement, making it more cost-effective. In both inline and offline coating, the primer must withstand the harsh conditions of the corrugating machine, as previously mentioned.

[0013] Embodiments of the present invention provide a method and apparatus in which a primer is applied in-line within a corrugating machine and then fed directly to the machine from a primer application station. This primed top layer becomes the printable portion of the fanfold that exits the corrugating machine. A typical primer formulation consists of 5-20% acrylic colloid polymer, 10-30% crosslinked styrenated acrylic emulsion, 20-50% styrene butadiene polymer, 0-6% inorganic filler, 10-15% polymer wax, 2-3% commonly used additives such as defoamers, pH adjusters, and biocides, and the remainder of the formulation is deionized water.

[0014] FIG. 1 is a schematic diagram of a corrugating machine 100 that applies a primer in-line in accordance with one embodiment of the present invention. In FIG. 1, a top liner 102 is coated with a primer 106 upon contact with an application roller 104. A doctor chamber 110 controls the amount of primer applied to the liner. The primer application station can be any commonly used coating station, such as an anilox coater 108 or roll coater. Coating stations are common equipment on corrugating machines, often used to apply a single color ink, such as Staples Red, before corrugating. In embodiments of the present invention, printing plates are not required because the ink application is full coverage. The primer application station can optionally include a dryer.

[0015] The primed top layer 114 passes over a central impression cylinder 112, which supports the liner during primer application, and idler rollers 116, which guide the liner, before being conditioned by a triple-stack steam drum 118. The triple-stack steam drum prepares the liner for gluing and joining the fluted middle layer of the corrugated board structure. The starch adhesive applied to the liner just before it enters the double-backer 120 adheres to the liner by conditioning on the triple-stack steam drum. Within the double-backer, the primed layer contacts a heated plate under pressure from the ballast belt above, forming the corrugated board structure. The primer layer can wear away within the double-backer.

[0016] The primer must enable high-quality UV inkjet printing by ensuring good dot spread of the UV inkjet droplets so that the image is formed uniformly and consistently, while avoiding excessive spread to maintain character definition. Furthermore, the primer must ensure good adhesion throughout the system. The primer must adhere well to the paper, and the ink must adhere well to the primer. Otherwise, the printed image may easily peel or chip off.

[0017] The primer must be able to withstand temperatures up to 135°C and the abrasion in the corrugating machine, and dry quickly enough so that it forms when it reaches the steam and abrasion areas in the corrugating machine. The primer must be hard enough so that it does not soften and sink into the paper under the high temperatures in the corrugating machine, and not wear away when it is subjected to pressure in the double backer where the corrugations are formed. Conversely, the primer must not be so hard that it becomes too chemically crosslinked, making it brittle and reducing adhesion.

[0018] 2 is a detailed schematic diagram of a portion of the corrugating machine of FIG. 1 in accordance with one embodiment of the present invention. The coating device 108 (FIG. 1) is an existing part of the corrugating machine, as it is typically used for a single-color flexographic ink printing process on the top layer of the corrugated board. In contrast to the prior art, embodiments of the present invention use a full-surface coating rather than using a printing plate to reverse print a single-color image.

[0019] In FIG. 2, the bottom liner board 205 and corrugated medium 206 make up the single-face corrugated board 207. The top liner 102 is primed after the mill roll stand 202 and before the preheater 203. The bonding device 200 is shown in FIG. 2 along with the double backer 120, which includes a heat plate 208 used to bond the top liner to the bonded medium and bottom liner. In FIG. 2, the preheaters 203 and 204 correspond to the steam drum 118 in FIG. 1. The finished sheet 209 is conveyed from the cardboard making machine via roller group 210. The primed corrugated sheet is then printed, cut, and folded as needed.

[0020] The language used herein has been chosen primarily for purposes of readability and explanation. It has not been chosen to delineate or limit the subject matter. Accordingly, it is intended that the scope of the claims be limited not by this detailed description, but by the claims issued based on this application. Accordingly, the disclosure of various embodiments is intended to illustrate, but not limit, the scope of the technology, which is set forth in the following claims.

Claims

1. 1. A method for processing fanfold corrugated board material in a corrugating machine for inkjet printing, comprising: applying a primer in-line to a top liner of fanfold corrugated board at a primer application station within the corrugating machine, the primer comprising 5-20% acrylic colloid polymer, 10-30% crosslinked styrenated acrylic emulsion, 20-50% styrene butadiene polymer, 0-6% inorganic filler, 10-15% polymer wax, 2-3% additives including any of an antifoaming agent, a pH adjuster, and a biocide, and the balance comprising deionized water; feeding the primed top liner from the primer application station to a double backer in the corrugating machine; Equipped with the primed top layer comprises the printable portion of the fanfold exiting the corrugating machine; method.

2. A corrugated cardboard manufacturing machine, a roller configured to apply a primer to the entire top liner at an in-line application station within the corrugating machine; a central impression cylinder configured to support the top liner while the primer is applied by the roller; an idler roller configured to guide the top liner; A triple-stack steam drum configured to prepare a liner for bonding and joining fluting interlayers of a corrugated board structure; and The primed top liner contacts the heating plate under pressure from the ballast belt, forming the double backer that forms the corrugated board structure. A cardboard manufacturing machine comprising:

3. 3. The corrugating machine of claim 2, wherein a doctor chamber controls the amount of primer applied to the top liner.

4. 3. The corrugating machine of claim 2, wherein the roller comprises either an anilox coater or a roll coater.

5. 3. The cardboard machine of claim 2, wherein the coating station further comprises a dryer.

6. the primer withstands temperatures and abrasion up to 135°C in the corrugating machine; the primer dries quickly enough so that it forms when it reaches the area of ​​the corrugating machine that is subject to steam and abrasion; The primer does not soften and sink into the top liner even under the high temperatures of the corrugating machine, the primer has sufficient hardness so that it does not wear away where the corrugations are formed under pressure in the double backer; and the primer is not so hard as to become brittle and lose adhesion, and is not chemically crosslinked; 3. The cardboard manufacturing machine according to claim 2.

7. the primer comprises 5-20% acrylic colloid polymer, 10-30% crosslinked styrenated acrylic emulsion, 20-50% styrene butadiene polymer, 0-6% inorganic filler, 10-15% polymer wax, 2-3% additives comprising any of an antifoaming agent, a pH adjuster, and a biocide, and the balance comprising deionized water; 7. The cardboard manufacturing machine according to claim 6.

8. A primer for application to fanfold corrugated board material in a corrugating machine for inkjet printing, comprising 5-20% acrylic colloid polymer, 10-30% crosslinked styrenated acrylic emulsion, 20-50% styrene butadiene polymer, 0-6% inorganic filler, 10-15% polymer wax, 2-3% additives including any of a defoamer, a pH adjuster, and a biocide, and the balance comprising deionized water.

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