# US 11,441,272 B2 · Method to produce a paperboard, a paperboard and a corrugated board

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,441,272 B2
- Document ID: US11441272B2
- Status: Granted
- Kind: B2
- Application number: 16/643,060
- Filed: 2018-08-30
- Published: 2020-10-22
- Granted: 2022-09-13
- Earliest claimed: 2017-09-01
- Assignees: Stora Enso OYJ
- Applicants: Stora Enso OYJ
- Inventors: Tuomo Sippus
- Web page: https://patentgrep.com/patent/US11441272B2

## CPC

- D21H 11/18: Highly hydrated, swollen or fibrillatable fibres
- B32B 7/12: using interposed adhesives or interposed materials with bonding properties
- B32B 29/005: {next to another layer of paper or cardboard layer}
- B32B 29/08: Corrugated paper or cardboard
- C08L 1/02: Cellulose; Modified cellulose
- D21D 1/20: Methods of refining
- D21F 9/006: {paper or board consisting of two or more layers}
- D21F 11/04: paper or board consisting on two or more layers
- D21F 11/12: Making corrugated paper or board
- D21H 27/30: Multi-ply (for surface covering D21H27/18; making on paper-making machines D21F9/00, D21F11/00)
- D21H 27/40: at least one of the sheets being non-planar, e.g. crêped (crêping or corrugating paper B31F)
- B32B 2250/02: 2 layers
- B32B 2250/26: All layers being made of paper or paperboard
- B32B 2307/558: Impact strength, toughness
- B32B 2307/718: Weight, e.g. weight per square meter
- B32B 2307/722: Non-uniform density
- B32B 2307/748: Releasability
- B32B 2439/00: Containers; Receptacles
- B32B 2553/00: Packaging equipment or accessories not otherwise provided for
- D21H: PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- D21D: TREATMENT OF THE MATERIALS BEFORE PASSING TO THE PAPER-MAKING MACHINE
- D21F: PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON

## Abstract

The present invention relates to a method for producing a paperboard comprising the steps of; providing a furnish comprising cellulosic fibers, applying the furnish on at least one wire to form a web, dewatering the web on said at least one wire by subjecting the web to a pressure above 150 kPa without the use of a press roll nip and thereafter pressing the dewatered web to form a paperboard. The invention also relates to a paperboard and a corrugated board.

## Claims

### Claim 1

A method for producing a paperboard comprising the steps of;
a) providing a furnish comprising cellulosic fibers,
b) applying the furnish on at least one wire to form a web,
c) dewatering the web on said at least one wire by subjecting the web to a pressure above 150 kPa without the use of a press roll nip and thereafter,
d) pressing the dewatered web to form a paperboard,
wherein the web comprises a first and second side and the dewatering is done from both sides of the web.

### Claim 2 (depends on 1)

The method according to claim 1 wherein the pressure is above 200 kPa.

### Claim 3 (depends on 1)

The method according to claim 1 wherein the amount of water removed from the first side of the web is between 35-65% by weight of the total amount of water removed and the water removed from the second side of the web is between 35-65% by weight of the total amount of water removed.

### Claim 4 (depends on 1)

The method according to claim 1 wherein the dry content of the web after pressing in step d) is above 45% by weight.

### Claim 5 (depends on 1)

The method according to claim 1 wherein the density of the paperboard is above 680 kg/m3.

### Claim 6 (depends on 1)

The method according to claim 1 wherein the paperboard comprises a thickness having a top, bottom and middle parts, and wherein a difference in density between the top and bottom parts of the thickness of the paperboard and the middle part of the thickness of the paperboard is at least 10%.

### Claim 7 (depends on 1)

The method according to claim 1 wherein a geometrical Short-span Compressive Test (SCT) index of the paperboard is above 32 Nm/g.

### Claim 8 (depends on 1)

The method according to claim 1 wherein the furnish comprises more than 50% by weight of NSSC pulp based on the total fiber amount.

### Claim 9 (depends on 1)

The method according to claim 1 wherein the furnish comprises 0.1-10% by weight of microfibrillated cellulose based on the total fiber amount.

### Claim 10 (depends on 1)

The method according to claim 1 wherein the increased pressure is achieved by changing the wrap angle of the wire over a roll in a dewatering section and/or by the use of vacuum.

### Claim 11 (depends on 1)

The method according claim 1 wherein the method further comprises the step of corrugating the paperboard to form a corrugated medium.

### Claim 12 (depends on 1)

The method according to claim 1 wherein the method further comprises the step of forming the paperboard into a liner.