Method for coating a fibrous web, and a surface coated fibrous web

Patent metadata

Field	Value
Publication number	US-12006633-B2
Application number	US-202017757257-A
Country	US
Kind code	B2
Filing date	Dec 22, 2020
Priority date	Dec 23, 2019
Publication date	Jun 11, 2024
Grant date	Jun 11, 2024

Abstract

A method is provided for coating a fibrous web, in particular a fibrous web comprising nanocellulose fibres. The method includes steps of applying a coating agent to a textured surface region of a textured substrate, applying a fibre furnish or a wet fibrous web onto the coated textured surface region of the textured substrate, optionally dewatering to provide a wet fibrous web, and drying said wet fibrous web such that at least a portion of said coating agent is transferred to said fibrous web. The method provides a coated fibrous web with improved barrier properties.

First claim

The invention claimed is:

1. A method for coating a fibrous web, said method comprising the steps of:
a. providing a textured substrate having at least one textured surface region,
b. applying a coating agent to the textured surface region of said textured substrate, so as to provide a coated, textured surface region of said textured substrate;
c. applying a fibre furnish onto the coated, textured surface region of said textured substrate; and dewatering said fibre furnish to provide a wet fibrous web, or,
d. applying a wet fibrous web onto the coated, textured surface region of said textured substrate;
e. drying said wet fibrous web from step c. or step d. such that at least a portion of said coating agent is transferred to said fibrous web, and
f. removing the fibrous web from said textured surface region after step e., thereby providing a coated fibrous web.

2. The method according to claim 1 , wherein said textured surface region has a predetermined texture.

3. The method according to claim 1 , wherein the fibrous web comprises cellulosic fibres.

4. The method according to claim 1 , wherein said textured substrate is a textured belt.

5. The method according to claim 1 , wherein said fibre furnish or said wet fibrous web is in contact with the coated textured surface region of said textured substrate for a length in a machine direction of at least 2 m.

6. The method according to claim 1 , wherein the coating agent comprises one or more coating components selected from a group consisting of waxes, oils, polar lipids, metallic soaps, rosins, and mixtures thereof.

7. The method according to claim 1 , wherein the coating agent comprises one or more coating components being an alkyl ketene dimer (AKD) or a fatty acid resin.

8. The method according to claim 1 , wherein the coating agent is a water in oil (W/O) emulsion or an oil in water (O/W) emulsion.

9. The method according to claim 1 , wherein the coating agent comprises one or more adhesion agents.

10. The method according to claim 1 , wherein the fibrous web comprises nanocellulose in an amount of between 0.01-100 wt % based on a total solids content.

11. The method according to claim 1 , wherein the textured surface region comprises a plurality of recesses such that the textured surface region has a cell volume of 0.5-1000 cm 3 /m 2 .

12. The method according to claim 1 , wherein the drying step takes place at a temperature above a melting point of at least one component of the coating agent.

13. The method according to claim 1 , wherein the drying step takes place at a temperature greater than 60° C. and at a temperature of less than 400° C.

14. The method according to claim 1 , wherein said coated fibrous web is transparent or translucent.

15. The method according to claim 1 , wherein said coated fibrous web is a coated, textured fibrous web.

16. The method according to claim 1 , wherein the coating composition is applied to the textured surface region in an amount of 0.1-100 gsm by dry weight.

17. The method according to claim 1 , wherein said coated fibrous web has at least one barrier property selected from a group consisting of: UV barrier, oil and grease barrier, oxygen barrier, aroma barrier, water vapour barrier, and combinations thereof.

18. The method according to claim 1 , wherein the fibrous web has a width, in a cross direction of the textured substrate, which is greater than 500 mm.

19. The method according to claim 1 , wherein excess coating agent is removed from the textured surface region prior to step c or step d.

Assignees

• Stora Enso Oyj

Inventors

• Backfolk Kaj
• Heiskanen Isto
• Nylén Otto

Classifications

• D21H27/02

  Patterned paper (patterned coatings D21H19/66; embossing B31F1/07; prepared on the paper-making machines D21F11/00) · CPC title

• D21H19/66

  Coatings characterised by a special visual effect, e.g. patterned, textured (marbled paper D21H27/04) · CPC title

• D21H19/28

  Polyesters · CPC title

• D21H19/16

  comprising curable or polymerisable compounds (D21H19/24 takes precedence) · CPC title

• D21F11/006

  Making patterned paper · CPC title