# US 2021/0276345 A1 · Apparatus and method for inkjet printing on flexible webs

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- Number: US 2021/0276345 A1
- Document ID: US20210276345A1
- Status: Published application
- Kind: A1
- Application number: 17/260,042
- Filed: 2019-07-15
- Published: 2021-09-09
- Earliest claimed: 2018-07-16
- Assignees: Xeikon Manufacturing N.V.
- Applicants: Xeikon Manufacturing N.V.
- Inventors: Tomas PRAET; Herman Jan Godelieve VAN DE STRAETE; Werner Jozef Johan OP DE BEECK; Roel DE MONDT; Lode Erik Dries DEPREZ
- Web page: https://patentgrep.com/patent/US20210276345A1

## CPC

- B41J 11/00214: {using UV radiation}
- B41J 2/21: for multi-colour printing
- B41J 11/00216: {using infrared [IR] radiation or microwaves}
- B41J 15/04: Supporting, feeding, or guiding devices; Mountings for web rolls or spindles
- B41J 2025/008: {comprising a plurality of print heads placed around a drum}
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS

## Abstract

An inkjet printing apparatus for printing on a substrate, such as a flexible packaging material, includes at least three inkjet heads including a first inkjet head, a second inkjet head, and at least one further inkjet head. At least one drying unit includes a first drying unit arranged opposite a first drying location which is located between the first and second inkjet location, the first drying unit being configured for physically removing liquid from ink applied by the first inkjet head. At least a first drum and a second drum, where the first and second inkjet locations as well as the first drying location are located on an outer surface of the first drum; and the at least one further inkjet location is located on an outer surface of the second drum.

## Claims

### Claim 1

An inkjet printing apparatus for printing on a substrate, such as a flexible packaging material, comprising:
at least three inkjet heads including a first inkjet head, a second inkjet head, and at least one further inkjet head;
a transport system configured for transporting the substrate from a first location opposite the first inkjet head to a second location opposite the second inkjet head, to at least one further location opposite the at least one further inkjet head; and
at least one drying unit comprising a first drying unit arranged opposite a first drying location which is located, seen in a transport direction of the substrate, between the first and second location, said first drying unit being configured for physically removing liquid from ink applied by the first inkjet head;
wherein the transport system comprises at least a first drum and a second drum on which the substrate is transported, and wherein the first and second locations as well as the first drying location are located on an outer surface of the first drum; and the at least one further location is located on an outer surface of the second drum.

### Claim 2 (depends on 1)

The apparatus of claim 1, wherein there are no guide elements in contact with a printed side of the substrate between the first and second drum.

### Claim 3 (depends on 1)

The apparatus of claim 1, wherein the transport system comprises a moving part configured to move at a moving speed and to transport the substrate on said moving part from the first location to the second location at a speed which is substantially the same as the moving speed.

### Claim 4 (depends on 1)

The apparatus of claim 1, wherein the first drying unit is configured for removing the liquid by evaporation.

### Claim 5 (depends on 1)

The apparatus of claim 1, wherein the at least two inkjet heads and the at least one drying unit associated with the first drum are positioned opposite an upper segment of the first drum, said upper segment describing an angle of less than 240°.

### Claim 6 (depends on 1)

The apparatus of claim 1, wherein no drying unit with a drying power larger than 50% of the drying power of the first drying unit is present between the first drum and the second drum seen along a transport path of the substrate.

### Claim 7 (depends on 1)

The apparatus of claim 1, wherein the at least one further inkjet head associated with the second drum comprises at least a first inkjet head and a second inkjet head arranged downstream of said first inkjet head seen in the transport direction of the substrate, wherein the second drum is configured for transporting the substrate from a first location opposite the first inkjet head associated with the second drum to a second location opposite the second inkjet head associated with the second drum; and wherein a drying unit is arranged between said first and second inkjet head, seen in the transport direction of the substrate.

### Claim 8 (depends on 1)

The apparatus of claim 1, wherein the at least one further inkjet head associated with the second drum is positioned opposite an upper segment of the second drum, said upper segment describing an angle of less than 240°.

### Claim 9 (depends on 1)

The apparatus of claim 1, wherein the first drum and/or the second drum has a diameter between 0.5 and 5 meters (m).

### Claim 10 (depends on 1)

The apparatus of claim 1, further comprising a main drying unit downstream of the transport system.

### Claim 11 (depends on 1)

The apparatus of claim 1, wherein the at least three inkjet heads comprise a third inkjet head arranged opposite the first drum, downstream of the second inkjet head seen in a transport direction of the substrate through the printing apparatus; and wherein the apparatus further comprises a second drying unit arranged, seen in the transport direction of the substrate, between the second and third inkjet head.

### Claim 12 (depends on 11)

The apparatus of claim 11, wherein the at least three inkjet heads comprise a fourth inkjet head arranged opposite the first drum, downstream of the third inkjet head seen in a transport direction of the substrate through the printing apparatus; and wherein the apparatus comprises a third drying unit arranged, seen in the transport direction of the substrate, between the third and fourth inkjet head.

### Claim 13 (depends on 12)

The apparatus of claim 12, wherein the first, second, third and fourth inkjet heads are configured to print four different colours.

### Claim 14 (depends on 1)

The apparatus of claim 1, wherein the transport system is configured to transport the substrate through the printing apparatus at a speed between 0.5 and 10 meters/second (m/s).

### Claim 15 (depends on 1)

The apparatus of claim 1, wherein the at least one drying unit comprises one or more of: an Ultraviolet (UV) dryer, a hot air dryer, an infrared (IR) or near-infrared (NIR) dryer, a microwave dryer, or any combination thereof.

### Claim 16

A method for printing on a substrate, preferably a flexible substrate such as a flexible packaging material, using at least three inkjet heads, said method comprising:
applying ink on a substrate at a first location on a first drum using a first inkjet head of said at least three inkjet heads;
physically removing liquid from ink applied by the first inkjet head, at a drying location on the first drum;
after the removing step, applying ink at a second location on the first drum using a second inkjet head of said at least three inkjet heads;
transporting the substrate from the first drum to a second drum; and
applying ink on the substrate at at least one further location on the second drum using at least one further inkjet head of said at least three inkjet heads.

### Claim 17 (depends on 16)

The method of claim 16, wherein applying ink on the substrate at at least one further location on the second drum comprises: applying ink using a further first inkjet head associated with the second drum; removing liquid from ink applied by the further first inkjet head; and applying ink using a further second inkjet head associated with the second drum, after said removing step.

### Claim 18 (depends on 16)

The method of claim 16, wherein the substrate is transported from the first drum to the second drum such that a printed side of the substrate is not brought in contact with any elements; and wherein the liquid is removed by evaporation.

### Claim 19 (depends on 16)

The method of claim 16, wherein the substrate is a non-fibrous flexible substrate.

### Claim 20 (depends on 16)

The method of claim 16, wherein the substrate is transported on a moving part from the first location to the second location at a speed which is substantially the same as a moving speed of the moving part.

### Claim at position 21

21-23. (canceled)