Method of slot die coating over deformable back-up roll

Patent metadata

Field	Value
Publication number	US-11712713-B2
Application number	US-201917309602-A
Country	US
Kind code	B2
Filing date	Dec 3, 2019
Priority date	Dec 13, 2018
Publication date	Aug 1, 2023
Grant date	Aug 1, 2023

Abstract

Methods and apparatuses for applying coatings ( 9 ) on a moving web ( 3 ) are provided. A slot die ( 20 ) and a back-up roll ( 11 ) engage with each other. The back-up roll has a deformable inner layer ( 12 ) with a surface thereof covered by a deformable outer layer ( 14 ). The slot die and the flexible web at a contacting area are impressed into the back-up roll with an engagement depth D, which enables formation of a coating having a substantially uniform thickness.

First claim

What is claimed is:

1. A method of applying a coating onto a web, the method comprising:
positioning a slot die having one or more die lips extending along a cross direction proximate to a back-up roll having a deformable inner layer with a surface thereof covered by a deformable outer layer, the inner layer being softer than the outer layer;
disposing a flexible web between the back-up roll and the one or more die lips;
dispensing a liquid coating material from the slot die onto the flexible web;
wherein the slot die is positioned proximate to the back-up roll such that the pressure of the liquid coating material between the slot die and the flexible web impresses the flexible web at a contacting area into the back-up roll with an engagement depth D wherein adjusting the engagement depth D in a range from about one micrometer to about 2 mm.

2. The method of claim 1 , further comprising metering a liquid flow through the slot die to control a wet thickness of the coating.

3. The method of claim 2 , wherein the wet thickness of the coating is adjusted to be within the range of about 1 to about 500 micrometers.

4. The method of claim 1 , wherein the flexible web has one or more surface non-flatness characteristics.

5. The method of claim 4 , wherein the flexible web is a baggy web.

6. The method of claim 4 , wherein the one or more surface non-flatness characteristics includes a splice, a web thickness variation, or a web wrinkle.

7. The method of claim 1 , wherein the flexible web is wrapped around the back-up roll where the liquid coating material is dispensed from the slot die onto the flexible web.

8. The method of claim 1 , wherein the back-up roll has an S-Factor measured against a rigid flat plate, averaged over a range of the engagement D from about 0.05 mm to about 1 mm, being less than about 15 (10 6 ·N/m 5/2 ), wherein

S
=

F

D
·

R
E

and F is force, D is the engagement depth, and RE=0.5.

9. The coating method of claim 1 , wherein the liquid coating material has a viscosity lower than about 10,000 centipoise (cps).

10. The coating method of claim 1 , wherein the deformable outer layer has a hardness greater than about 40 Shore A.

11. The coating method of claim 1 , wherein the deformable inner layer has a hardness less than about 20 Shore A.

Assignees

• 3M Innovative Properties Company

Inventors

• Dodds Shawn C
• Rattray Tyler J
• Meyers Kara A
• Pekurovsky Mikhail L
• Ciliske Scott L
• Dobbs James N
• Javid Samad

Classifications

• B05C13/00

  Means for manipulating or holding work, e.g. for separate articles {(B05C1/0821 takes precedence)} · CPC title

• B05D1/265 Primary

  Extrusion coatings · CPC title

• B05C5/0254 Primary

  Coating heads with slot-shaped outlet (B05C5/0283 takes precedence) · CPC title

• B05C1/083

  being passed between the coating roller and one or more backing rollers · CPC title

• B05C5/027

  Coating heads with several outlets, e.g. aligned transversally to the moving direction of a web to be coated (B05C5/0254 takes precedence) · CPC title