Method and device for starch application

Patent metadata

Field	Value
Publication number	US-11767638-B2
Application number	US-201917263634-A
Country	US
Kind code	B2
Filing date	Jul 9, 2019
Priority date	Jul 27, 2018
Publication date	Sep 26, 2023
Grant date	Sep 26, 2023

Abstract

A method and a device for the application of starch on a moving fiber web, especially on a packaging paper web such as a testliner or a corrugated medium web, include first applying starch to a first roll and/or a second roll and passing the fiber web through a treatment nip formed by the first roll and the second roll. At least one of the first or the second roll, preferably both rolls, have a hardness of 15 P&J (Pusey & Jones) or lower, preferably 5 P&J or lower and most preferably 1 P&J or lower. The starch is applied to the first roll and/or the second roll by a slot die and/or a slide die and then transferred to the fiber web in the treatment nip.

First claim

The invention claimed is:

1. A device for the application of starch on a moving fiber web, the device comprising:
a first roll and a second roll positioned to form a treatment nip for the fiber web, said first roll and said second roll each having an outer layer or cover with a hardness of 1 P&J (Pusey & Jones) or lower; and
an applicator for applying starch on at least one of said rolls, said applicator including at least one of a slot die or a slide die forming a free-falling curtain of starch with at least one of a solid content between 6% and 25% or a viscosity between 5 mPas and 60 mPas.

2. The device according to claim 1 , wherein:
said free-falling curtain of starch has at least one of a solid content between 8% and 18%.

3. The device according to claim 1 , wherein:
said free-falling curtain of starch has a viscosity between 10 mPas and 40 mPas.

4. The device according to claim 1 , which further comprises a device for removing an air boundary layer from at least one of said first roll or said second roll.

5. The device according to claim 4 , wherein said device for removing the air boundary layer includes at least one of a doctor blade, an air jet, a brush or a foil.

6. The device according to claim 4 , wherein said first roll and said second roll have diameters being identical or differing by less than 10%.

7. The device according to claim 4 , wherein at least one of said first roll or said second roll has a diameter of between 0.25 m and 2 m.

8. The device according to claim 4 , wherein at least one of said first roll or said second roll has a diameter of between 0.7 m and 1.8 m.

9. The device according to claim 4 , wherein at least one of said rolls has:
said cover and said cover is formed of a metal or a ceramic with a layer thickness of less than 1 mm, or
said cover and said cover is formed of a rubber, a polyurethane or a composite material with a layer thickness of between 10 mm and 20 mm.

10. The device according to claim 9 , wherein said cover formed of a metal or a ceramic has a layer thickness of between 50 μm and 150 μm.

11. The device according to claim 4 , wherein at least one of said first roll or said second roll has at least one sensor for measuring a nip load.

12. The device according to claim 1 , wherein at least one roll selected from the group consisting of said first roll and said second roll is a controlled deflection roll.

Assignees

• Voith Patent Gmbh

Inventors

• Henninger Christoph
• Doermann Michael

Classifications

• D21H19/54 Primary

  Starch · CPC title

• B05C1/0834

  the coating roller co-operating with other rollers, e.g. dosing, transfer rollers · CPC title

• B05C5/008

  Slide-hopper curtain coaters · CPC title

• D21G9/009

  Apparatus for glaze-coating paper webs · CPC title

• D21H17/28

  Starch · CPC title